GIT a94420b9eb297332a4c66a978f228270468623cc git+ssh://master.kernel.org/pub/scm/linux/kernel/git/ezk/unionfs.git commit a94420b9eb297332a4c66a978f228270468623cc Author: Erez Zadok Date: Thu Dec 13 18:36:32 2007 -0500 Unionfs: clarify usage.txt mount options CC: Jim Kissel Signed-off-by: Erez Zadok commit f7ca7e43445d888589e20817106007e241e050b6 Author: Erez Zadok Date: Wed Dec 12 22:40:15 2007 -0500 Unionfs: avoid using drop_pagecache_sb in remount Exporting drop_pagecache_sb to modules is somewhat risky because one cannot sleep inside invalidate_mapping_pages. This could cause a lot of latency in the pre-emption code. So don't export this symbol to minimize the risk that others will use it. Instead, unionfs will try to directly invalidate as many pages it can from the unionfs_remount code. Invalidating those inode pages is not strictly required, but helpful in encouraging a revalidation of inodes sooner than waiting for individual f/s ops to access the union. Since a remount is already an expensive but rare operation, this inode pages invalidation shouldn't add too much overhead. CC: Nick Piggin Signed-off-by: Erez Zadok commit 8aa8d4e5939a79c06b087eed9f2a7a5dea4599ce Author: Erez Zadok Date: Fri Dec 7 19:55:12 2007 -0500 Unionfs: reduce the amount of cache-coherency debugging messages Signed-off-by: Erez Zadok commit 4850b3f7b10aa80c22ad70782187dd70bfd0a9f3 Author: Erez Zadok Date: Fri Dec 7 19:54:59 2007 -0500 Unionfs: cleanup/consolidate branch-mode parsing code Also a bug fix: disallow unrecognized branch modes at mount time, instead of defaulting to "rw". Signed-off-by: Erez Zadok commit a7170c1808f3dd6a8a2671d6cd0ce3bc1f563334 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: use generic_file_aio_read/write There's no apparent need to define our own aio_read/write methods. Signed-off-by: Erez Zadok commit a98fda2ee3d769d13e89a4dba569fda10d89a7a3 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: update our inode size correctly upon partial write Signed-off-by: Erez Zadok commit 44826bc5b9c8cfa76ae31f55713cb9ddc4f06318 Author: Erez Zadok Date: Mon Nov 26 19:44:04 2007 -0500 Unionfs: prevent multiple writers to lower_page Without this patch, the LTP fs test "rwtest04" triggers a BUG_ON(PageWriteback(page)) in fs/buffer.c:1706. CC: Hugh Dickins Signed-off-by: Erez Zadok commit ae21a5caa75efeb0461f1d2a7d96e5a923040516 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: support splice(2) Also remove redundant variable from unionfs_readpage (saves a bit on stack space). Signed-off-by: Erez Zadok commit ff9991101ffb63a336d90646bcef1e2b43c79998 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: reintroduce a bmap method This is needed for swapon(2) files in the union. Signed-off-by: Erez Zadok commit 8e3b3618fbedb033bce63cc865dda0b8dbfe8d56 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: update times in setattr Needed to maintain Unix semantics via utimes(2). Signed-off-by: Erez Zadok commit 635f9297dfad4cff12574d453c33c07d2a26704c Author: Erez Zadok Date: Sun Nov 25 23:39:46 2007 -0500 Unionfs: create opaque directories' whiteouts unconditionally Needed to maintain Unix semantics (LTP testing). Signed-off-by: Erez Zadok commit 65cfcd84534cddc39ad1e1fcb3d94b3b10985948 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: don't create whiteouts on rightmost branch If we are unlinking/rmdir'ing an object on the rightmost branch, there's no need to create a whiteout there: this saves on storage space and inodes. Also, in the (degenerate) case of having only one branch, this really saves on whiteouts. CC: Hugh Dickins Signed-off-by: Erez Zadok commit abd2b310c5d1a029ea11e807eeb205b127c70b32 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: release lower resources on successful rmdir This patch prevents those resources from lingering around until memory pressure would have forced them out. The patch also properly handles directories that have been rmdir'ed which are still some process's cwd. CC: Hugh Dickins Signed-off-by: Erez Zadok commit 60eaec57cb053d3d0e60991e907502aa9980a68d Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: remove useless debugging messages These are considered normal behaviour, they don't really reveal any insight to the person debugging the code, and they tend to clutter console messages. Signed-off-by: Erez Zadok commit 74a433a9040791d2e2d8d24f3aaead0f2e994d5c Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: handle whiteouts more efficiently in filldir If we cache a dirent for file "foo", and then it gets deleted, then we look for a ".wh.foo" whiteout entry in the same dirent cache. But our dirent cache strips the ".wh." prefix, thus looking for an entry named "foo" whose filldir_node->whiteout should be 1 instead of 0. In that case, don't display an incorrect printk message that the file system may be corrupt, but set that filldir_node->whiteout to 1. CC: Hugh Dickins Signed-off-by: Erez Zadok commit 5fa9020acbdc6b823b348e03f74cdc13097f087e Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: set lower mnt after mkdir which resulted in copyup Signed-off-by: Erez Zadok commit 944a2c5c4f2c208c60931a5f2bed4159a387f445 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: minor cleanup in the debugging infrastructure Signed-off-by: Erez Zadok commit 52d66cb4fc6c6ae5a9db9283d0de357d51ccda32 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: minor coding standards applied Signed-off-by: Erez Zadok commit 0f4f3805e25d39c58ca5cba67e80ff666652e828 Author: Hugh Dickins Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: minor cleanup in writepage Signed-off-by: Erez Zadok commit c0d8732b285f675f788a3ce385e8d5e1921f8345 Author: Erez Zadok Date: Sun Nov 25 20:01:17 2007 -0500 Unionfs: use f_path instead of f_dentry/mnt Signed-off-by: Erez Zadok commit 3089bd91cfa75366f16bf3a1db54067807c44023 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: move debugging checks inside locks This is to ensure that the objects we want to check aren't being destroyed or changed by another thread. Signed-off-by: Erez Zadok commit 1fd4be17e703ed88304b9682888c599f4512a807 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: fold do_readpage into unionfs_readpage Simplify the code and reduce stack pressure a bit. Signed-off-by: Erez Zadok commit 1f5e88fff622d6fe526a5417d15b490bd06b6976 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: remove unnecessary lower atime updates No need for this because our readpage calls vfs_read on the lower objects, which would update the atime as/if needed. Signed-off-by: Erez Zadok commit c1b16828093831079b0234e5664121f4acbc4130 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: debugging updates Don't perform dentry+inode checks unless both are valid. Signed-off-by: Erez Zadok commit e523db366791ab9e82588cc68337df3623d4c958 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: clear partial read in readpage Signed-off-by: Hugh Dickins Signed-off-by: Erez Zadok commit ebfd92875f44c1883753e63cc6fbc9e24479a5c9 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: writepage updates Don't set/reset the PageUptodate flag on our page. Call flush_dcache_page on the lower page after copy_highpage, and set it uptodate. Call set_page_dirty right before clear_page_dirty_for_io. CC: Hugh Dickins Signed-off-by: Erez Zadok commit dd1ef6550432c1b4a51dbf2ea18c221c542e9fcf Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: update cache-coherency detection heuristics Use a small delay to reduce the number of times unionfs has to detect changed mtime's/ctime's, and also reduce the potential for false positives. See Documentation/filesystems/unionfs/concepts.txt for a detailed discussion. Signed-off-by: Erez Zadok commit 14691bdfca36a8e6ba01a0bd88b34b913ae64be6 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: use i_size wrappers Signed-off-by: Erez Zadok commit 1d55610574e44390e7b3d6ab2867b5a2aa2c6284 Author: Erez Zadok Date: Tue Nov 13 03:12:20 2007 -0500 Unionfs: flush and release updates Remove the totalopens counter which was intended to reduce unnecessary processing of d_deleted dentries. Move that processing from file_release to flush. Cc: Hugh Dickins Signed-off-by: Erez Zadok commit 2cb6155cf68ce34346b0bac3654fe77ea2e9855d Author: Erez Zadok Date: Fri Nov 2 20:03:21 2007 -0400 Unionfs/VFS: no need to export 2 symbols in security/security.c Signed-off-by: Erez Zadok commit ab3160df0288773eb208828ac91874ee526e35f6 Author: Erez Zadok Date: Fri Nov 2 19:01:54 2007 -0400 Unionfs: don't printk an error if it's due to common copyup Signed-off-by: Erez Zadok commit 9eeef9a9fb26c7fd0fb6436b9310cd8be320fdcf Author: Erez Zadok Date: Fri Nov 2 19:01:54 2007 -0400 Unionfs: don't bother validating inode if it has no lower branches Signed-off-by: Erez Zadok commit b959c4bd60a5846b3866534134b4022b1d27df86 Author: Erez Zadok Date: Fri Nov 2 19:06:09 2007 -0400 Unionfs: avoid a deadlock during branch-management on a pivot_root'ed union Signed-off-by: Erez Zadok Acked-by: Herton Ronaldo Krzesinski commit 5b2d7b13da60dee131e5d99953e5d1ed2b7e126d Author: Erez Zadok Date: Fri Nov 2 19:01:54 2007 -0400 Unionfs: mmap updates Rewrite unionfs_writepage to minimize dependence on AOP_WRITEPAGE_ACTIVEATE, handle memory pressure better, and update documentation. Remove unionfs_sync_page because it's not needed. CC: Hugh Dickins CC: Pekka Enberg Signed-off-by: Erez Zadok commit 78eb8ff1526c9a08b3f66914e2178c9ebf41a279 Author: Erez Zadok Date: Fri Nov 2 20:28:18 2007 -0400 Unionfs: update usage.txt documentation Signed-off-by: Erez Zadok commit 7d593320ad1aafedc5f88d0c6cb1149041519f28 Author: Erez Zadok Date: Fri Nov 2 19:01:54 2007 -0400 Unionfs: cleanup permission checking code Use vfs helpers and avoid redundant checks performed by the VFS already. Signed-off-by: Erez Zadok commit 2f6190c1b34c99dd780b91ddeaabb4c1fdf1ab3d Author: Erez Zadok Date: Fri Nov 2 19:01:54 2007 -0400 Unionfs: delete whiteouts in sticky directories This is needed to maintain Unix semantics. Signed-off-by: Erez Zadok commit 5789493be228d89ae39a6acaa548fa1405f53a47 Author: Erez Zadok Date: Sun Oct 21 16:13:26 2007 -0400 Unionfs: remove obsolete #define and comment Signed-off-by: Erez Zadok commit 12d6d6d03dd908896542b25ecaef21230ae7ef08 Author: Jeff Layton Date: Sun Oct 21 16:13:36 2007 -0400 Unionfs: fix unionfs_setattr to handle ATTR_KILL_S*ID Don't allow unionfs_setattr to trip the BUG() in notify_change. Clear ATTR_MODE if the either ATTR_KILL_S*ID is set. This also allows the lower filesystem to interpret these bits in its own way. Signed-off-by: Jeff Layton Cc: Josef 'Jeff' Sipek Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Erez Zadok commit aa1eb3fa0b81e1c90667be9247ef899f8ca169e6 Author: Erez Zadok Date: Thu Oct 18 17:16:51 2007 -0400 Unionfs: remove for_writepages nfs workaround This is no longer necessary since struct writeback_control no longer has a fs_private field which lower file systems (esp. nfs) use. Plus, unionfs now defines its own ->writepages method. Signed-off-by: Erez Zadok commit 9c09bf0162dd5a52bc5b085b8094e234a889f806 Author: Erez Zadok Date: Thu Oct 18 14:03:16 2007 -0400 Unionfs: convert a printk to pr_debug in release This is mostly an informational message, not an error. Signed-off-by: Erez Zadok commit 99ec7bc85cc3cad82e8981da028f980809ef7e04 Author: Erez Zadok Date: Wed Oct 17 17:35:02 2007 -0400 Unionfs: don't bother validating dentry if it has no lower branches Signed-off-by: Erez Zadok commit 13b7216b8a976a2d28b591d31c31afde59fbcc4d Author: Erez Zadok Date: Wed Oct 17 16:37:51 2007 -0400 Unionfs: don't printk trivial message upon normal rename-copyup Signed-off-by: Erez Zadok commit ade6e96277c808d43bf71cdfa20ae874275e1b71 Author: Erez Zadok Date: Tue Oct 16 10:50:16 2007 -0400 Unionfs: support lower filesystems without writeback capability Implement unionfs_writepages. As per mm/filemap.c:__filemap_fdatawrite_range(), don't call our writepage if the lower mapping has BDI_CAP_NO_WRITEBACK capability set. Signed-off-by: Pekka J Enberg Signed-off-by: Erez Zadok commit 0b8f4c73f1bde8724680c2d0e040f8bfba0308b3 Author: Andrew Morton Date: Thu Oct 18 15:54:55 2007 -0400 Unionfs: slab api remove useless ctor parameter and reorder parameters fs/unionfs/super.c: In function 'unionfs_init_inode_cache': fs/unionfs/super.c:874: warning: passing argument 5 of 'kmem_cache_create' from incompatible pointer type Cc: Christoph Lameter Cc: Josef 'Jeff' Sipek Signed-off-by: Andrew Morton Signed-off-by: Erez Zadok commit a7edc24ee2b7a368004c7f986db8591e79240671 Author: Andrew Morton Date: Thu Oct 18 15:50:15 2007 -0400 Unionfs: security convert lsm into a static interface fix ERROR: "security_inode_permission" [fs/unionfs/unionfs.ko] undefined! ERROR: "security_file_ioctl" [fs/unionfs/unionfs.ko] undefined! Need these back. Cc: "Serge E. Hallyn" Cc: Arjan van de Ven Cc: Chris Wright Cc: James Morris Cc: Stephen Smalley Cc: Josef 'Jeff' Sipek Signed-off-by: Andrew Morton Signed-off-by: Erez Zadok commit a5dea2817e6d31db32b6c1e10f0da1715088e61d Author: Erez Zadok Date: Fri Sep 28 16:10:42 2007 -0400 Unionfs: coding style: avoid lines longer than 80 chars Signed-off-by: Erez Zadok commit b9e0f7591fa822138e81313d5a059cba2b74cb8d Author: Erez Zadok Date: Fri Sep 28 16:10:15 2007 -0400 Unionfs: coding style: miscellaneous fixes No braces around single-statement if's. No externs in .c files. use not . Use (foo *) not (foo*). Signed-off-by: Erez Zadok commit e6909cf934a9f51ef6146eaa5979a95beb464bcd Author: Erez Zadok Date: Fri Sep 28 16:08:35 2007 -0400 Unionfs: coding style: avoid multiple assignments on same line Signed-off-by: Erez Zadok commit 57cc55ddd2ad02134e5477e8a0ef0ca7ebc9636a Author: Erez Zadok Date: Fri Sep 28 15:47:25 2007 -0400 Unionfs: coding style: take assignments out of "if" conditions Signed-off-by: Erez Zadok commit 5a88de491733e08a74a2344edfc1bbb498024910 Author: Erez Zadok Date: Sun Sep 30 13:02:36 2007 -0400 Unionfs: coding style: proper spacing Signed-off-by: Erez Zadok commit 42c0f3787adc354a8844e77bbccabb5c6a8dc44e Author: Erez Zadok Date: Fri Sep 28 02:26:31 2007 -0400 Unionfs: use braces in both branches of conditionals As per CodingStyle, if one branch of an if-then-else has braces because it has multiple statements, then the other branch should have braces too, even if the other branch has only one statement in it. Signed-off-by: Erez Zadok commit 80b9bc1f8f85b233fd6d8a99c8006996ae10a233 Author: Erez Zadok Date: Fri Sep 28 02:05:21 2007 -0400 Unionfs: remove periods from the end of printk strings Signed-off-by: Erez Zadok commit cd7d35022c837ae884e64fddc93e42dd55be2947 Author: Erez Zadok Date: Fri Sep 28 02:00:56 2007 -0400 Unionfs: update/assign a KERN_* level to all printk statements Also use pr_info() instead of printk(KERN_INFO ...) Signed-off-by: Erez Zadok commit a6546ac74c143e8a3443ef3989a7d45152664252 Author: Erez Zadok Date: Fri Sep 28 01:42:04 2007 -0400 Unionfs: add missing newlines in printk's Signed-off-by: Erez Zadok commit 036de7da9c4d363c009f7b8c1193b5b97001435f Author: Erez Zadok Date: Fri Sep 28 01:38:43 2007 -0400 Unionfs: convert all appropriate printk's to pr_debug calls Signed-off-by: Erez Zadok commit 98021bee1c7b7ba8031ab324cc435ba922a1127a Author: Erez Zadok Date: Fri Sep 28 01:06:22 2007 -0400 Unionfs: use pr_debug() instead of custom dprintk() Also turn on DEBUG if CONFIG_UNION_FS_DEBUG is on Signed-off-by: Erez Zadok commit a9124c01dff3aa1c0e6cde8906b0b002c54359da Author: Erez Zadok Date: Fri Sep 28 00:31:12 2007 -0400 Unionfs: use page_offset() helper Signed-off-by: Erez Zadok commit 43560c9ab4b8e22b5298bf59a15733829f88f060 Author: Erez Zadok Date: Fri Sep 28 00:25:20 2007 -0400 Unionfs: remove unnecessary if condition The condition is always true there. Signed-off-by: Erez Zadok commit 72782c91c13ffd16b9b99a10676ee36ad6fc7e61 Author: Erez Zadok Date: Fri Sep 28 00:23:18 2007 -0400 Unionfs: properly indent static struct Signed-off-by: Erez Zadok commit b0ad2ef66aa710a8fce18a592a7eb2826a423a64 Author: Erez Zadok Date: Fri Sep 28 00:23:56 2007 -0400 Unionfs: use UNIONFS_NAME macro Signed-off-by: Erez Zadok commit 91252d392ab15550f87c6120c85ea4176dc8b7bc Author: Erez Zadok Date: Fri Sep 28 00:24:11 2007 -0400 Unionfs: use consistent printk prefixes Signed-off-by: Erez Zadok commit 5fea73bb4a5a35c9f89757e5ac4852e61de13995 Author: Erez Zadok Date: Fri Sep 28 00:23:45 2007 -0400 Unionfs: minor comment cleanups Signed-off-by: Erez Zadok commit ddef32eb04ddd6894ee0b79255d2c4bb86b8b72a Author: Erez Zadok Date: Fri Sep 28 00:08:03 2007 -0400 Unionfs: add un/likely on conditionals Signed-off-by: Erez Zadok commit 426e1b18714dfd434cac23b79e1060f2691b6339 Author: Erez Zadok Date: Sat Sep 29 01:05:01 2007 -0400 Unionfs: compile if debug is off Signed-of-by: John Johansen Signed-off-by: Erez Zadok commit cdc13d77f4d9fa17af9661f02fc04f3898a419ef Author: Erez Zadok Date: Thu Sep 27 22:20:41 2007 -0400 Unionfs: use poison.h for safe poison pointers This also fixes a compile warning on 64-bit systems. Signed-off-by: Josef 'Jeff' Sipek Signed-off-by: Erez Zadok commit ccf8cb1dfa8a34fab9f56d56e10368cc20c11ac5 Author: Erez Zadok Date: Tue Sep 25 22:59:57 2007 -0400 Unionfs: lower nameidata support for nfsv4 Pass nameidata structures as needed to the lower file system, support LOOKUP_ACCESS/OPEN intents. This makes unionfs work on top of nfsv4. Signed-off-by: Erez Zadok Acked-by: Josef 'Jeff' Sipek commit 1db41602cf657448c14a8af6d5e90bfdd280512a Author: Erez Zadok Date: Mon Sep 24 11:38:35 2007 -0400 Unionfs: add lower nameidata debugging support Signed-off-by: Erez Zadok commit 1348b0bfd64da023f756b4456e8e511087883912 Author: Erez Zadok Date: Mon Sep 24 11:38:35 2007 -0400 Unionfs: minor coding style updates Signed-off-by: Erez Zadok commit 022fc95bfa4e9a0cdc573f798898992326a0bede Author: Erez Zadok Date: Tue Sep 25 23:00:22 2007 -0400 Unionfs: cast page->index loff_t before shifting Fixes bugs in number promotion/demotion computation, as per Signed-off-by: Erez Zadok Acked-by: Josef 'Jeff' Sipek commit 7f7fb4bb2196689882ebd37cf477756ac76513fb Author: Olivier Blin Date: Mon Sep 24 22:50:53 2007 -0400 Unionfs: cache-coherency fixes Do not update mtime if there is no upper branch for the inode. This prevents from calling unionfs_lower_inode_idx() with a negative index, which triggers a bug. Signed-off-by: Olivier Blin Signed-off-by: Erez Zadok commit 226bdf03c9ff97ea8ab4aeb52f4c0f36622d71d4 Author: Erez Zadok Date: Tue Sep 25 22:59:31 2007 -0400 Unionfs: display informational messages only if debug is on This is to avoid filling the console/logs with messages that are primarily of debugging use. Signed-off-by: Erez Zadok Acked-by: Josef 'Jeff' Sipek commit 2651f9727892c77f812c6441249df6da8f06a750 Author: Josef 'Jeff' Sipek Date: Mon Sep 24 22:52:51 2007 -0400 Unionfs: Remove unused #defines Signed-off-by: Josef 'Jeff' Sipek Signed-off-by: Erez Zadok commit 2d14124f7c1245965920df31cf06e9568193cef7 Author: Josef 'Jeff' Sipek Date: Mon Sep 24 22:52:51 2007 -0400 Unionfs: Simplify unionfs_get_nlinks Since we set the right value for d_type in readdir, there's really no point in having to calculate the number of directory links. Some on-disk filesystems don't even store the number of links for directories. Signed-off-by: Josef 'Jeff' Sipek Signed-off-by: Erez Zadok commit 5682020b40e1c056f90ed34b0a3b63bd1ad22b0a Author: Erez Zadok Date: Wed Sep 19 14:48:22 2007 -0400 Unionfs: cache coherency after lower objects are removed Prevent an oops if a lower file is deleted and then it is stat'ed from the upper layer. Ensure that we return a negative dentry so the user will get an ENOENT. Properly dput/mntput so we don't leak references at the lower file system. Signed-off-by: Erez Zadok Acked-by: Josef Sipek commit 1f9df48c2b910ce32ab033c760395a36b9ed4a98 Author: Erez Zadok Date: Wed Sep 19 14:48:22 2007 -0400 Unionfs: unionfs_lookup locking consistency Ensure that our lookup locking is consistent and symmetric: if a lock existed before calling lookup_backend, it should remain so; only if performing a lookup of a known new dentry, should lookup_backend return a newly-locked dentry-inode info (and only if there was no error). Document this behavior. This cleanup allowed us to remove two unnecessary int declarations. Signed-off-by: Erez Zadok Acked-by: Josef Sipek commit b43ee3b1263f2e89bd0b60137ba1dd7476f2e4af Author: Erez Zadok Date: Wed Sep 19 15:40:42 2007 -0400 Unionfs: check integrity only if validated dentry successfully Signed-off-by: Erez Zadok Acked-by: Josef Sipek commit 892efa9f49fc7d43d8e4ca1ca057009346b2348b Author: Erez Zadok Date: Wed Sep 19 14:48:16 2007 -0400 Unionfs: add missing newlines to printks Signed-off-by: Erez Zadok Acked-by: Josef Sipek commit cf03dee3e0af201c1f33f174fddbc3862022099d Author: Erez Zadok Date: Wed Sep 19 14:48:22 2007 -0400 Unionfs: remove unnecessary comment Signed-off-by: Erez Zadok Acked-by: Josef Sipek commit ca85d7e67a49b147e092eec7a0cc59745427a859 Author: Erez Zadok Date: Wed Sep 19 14:48:22 2007 -0400 Unionfs: use bool type in dentry and file revalidation code Signed-off-by: Erez Zadok Acked-by: Josef Sipek commit 9da03e6635d2e97ef1bfe4aef5621869b087f0b0 Author: Josef 'Jeff' Sipek Date: Fri Aug 31 19:31:58 2007 -0400 Unionfs: unionfs_create rewrite The code was hard to follow and violated some invariants (e.g., never modify a read only branch, and always create on branch 0). Signed-off-by: Josef 'Jeff' Sipek commit e2cb8b1f58b0a488c826e287c59e781191cc1e34 Author: Erez Zadok Date: Tue Sep 4 18:15:49 2007 -0400 Unionfs: debugging and validation of fan-out invariants Introduce debugging functionality, Makefile support to turn it on at compile time, and hooks in the main code to verify fan-out invariants. This is very similar to how other file systems provide debugging functionality. This code has been very useful in detecting and fixing problems, especially when stacking on top of assorted file systems. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 3663f07e0f9b6508447bcf04a8ee34d94673261e Author: Erez Zadok Date: Mon Sep 3 19:53:58 2007 -0400 Unionfs: update unionfs version number Update version number from 2.0 to 2.1 to reflect the amount of work that had gone in since 2.0 was first released, and also to sync up with Unionfs 2.x releases for earlier kernels. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit e00853534e377c1993f9b3918f2b06a1c0bbb5b5 Author: Erez Zadok Date: Fri Aug 31 19:07:34 2007 -0400 Unionfs: assorted comment and style updates Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 88770e1a1b234a4af2c6858fd19918d180609a98 Author: Erez Zadok Date: Fri Aug 31 18:59:25 2007 -0400 Unionfs: use file f_path field Start using file->f_path.dentry instead of file->f_dentry Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 6eb48193bac6b2f5c49aa24ef29d06c2d60543a0 Author: Erez Zadok Date: Fri Aug 31 18:55:36 2007 -0400 Unionfs: extended attributes fixes Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 7018cbd4b405ba3956da4b087389c2b210ae75ae Author: Erez Zadok Date: Fri Aug 31 18:55:08 2007 -0400 Unionfs: minor remount fixes Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 29c3c99e092257e1b55828c62357a43b435f2c63 Author: Erez Zadok Date: Fri Aug 31 18:53:43 2007 -0400 Unionfs: readonly branch test fix Bug fix to test if a lower branch is readonly, even when given negative dentries. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 1d80c4ad5a1cb7df367366d1662b6b30a7ddbcdf Author: Erez Zadok Date: Fri Aug 31 18:49:51 2007 -0400 Unionfs: remove old nfsro option Ensure that a branch set as 'ro' behaves like a real readonly mounted lower file system. This allows us to remove the old 'nfsro' option. Now unionfs handles even an readonly exported NFS file system, which was mounted on the client in readwrite mode. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit f65ed1ad946021c190d8b83c7c03ca9ec908f20a Author: Erez Zadok Date: Fri Aug 31 18:49:29 2007 -0400 Unionfs: mount-time option parsing fix Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 86b1dc453436767eca919004b07da89f672abef0 Author: Erez Zadok Date: Fri Aug 31 18:46:38 2007 -0400 Unionfs: handling lower vfsmount fixes Properly increase/release lower vfsmounts. Validate proper use of unionfs mntget/put. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 5fca017890a3adfffed6948387bb2477dfc0e315 Author: Erez Zadok Date: Fri Aug 31 18:38:58 2007 -0400 Unionfs: mmap fixes Most important fixes prevent deadlocks especially under low-memory conditions, when one is not supposed to cause more memory pressure; also handle AOP_WRITEPAGE_ACTIVATE from lower file systems. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 5cef4ebd3f59298414c21d60ff3106ec8ccea743 Author: Erez Zadok Date: Fri Aug 31 18:36:38 2007 -0400 Unionfs: lower nameidata support Create and free custom nameidata structures, and pass them to lower file systems when needed via vfs_create. (This code will get updated when/if nameidata is split into an intent structure and a VFS-level only structure.) Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 7116cf222b57fdd156bc0c201ae469952293da64 Author: Erez Zadok Date: Fri Aug 31 18:35:08 2007 -0400 Unionfs: partial_lookup update Handle new semantics of lookup_backend. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit dce4cb4a1d8f494cc6df9be240e5096c6b08727f Author: Erez Zadok Date: Fri Aug 31 18:34:36 2007 -0400 Unionfs: unionfs_ioctl bug fixes Properly update lower objects, and release lower mnts upon ioctl success or failure. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 03d35b8f4af39c809bff12e41a511693a6424f33 Author: Erez Zadok Date: Fri Aug 31 18:30:56 2007 -0400 Unionfs: interpose updates Update unionfs_interpose to handle spliced dentries, which is important for NFS exporting. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 10cc5f50b17d38b9a3948677bc7bc03aa4511bb1 Author: Erez Zadok Date: Fri Aug 31 18:30:07 2007 -0400 Unionfs: minor file_release updates Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit a19e1a39e64d2abcf4da22aa517e0830431c07c3 Author: Erez Zadok Date: Fri Aug 31 18:28:02 2007 -0400 Unionfs: implement f/async Unionfs needs its own fsync and fasync instead of calling the generic file_fsync, because it may have to sync multiple writable lower branches (not just one). This also allows Unionfs to compile with CONFIG_BLOCK=n. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 44f3a130b37a04a5e84791902eef7d3fc25255a8 Author: Erez Zadok Date: Fri Aug 31 18:27:14 2007 -0400 Unionfs: file_revalidate updates Correctly revalidate a file and account for lower mnts, even when branches are updated or inserted. Better info upon file copyup. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 238c143e734164ec43ba8853af315b41eb0dcb4a Author: Erez Zadok Date: Fri Aug 31 16:57:56 2007 -0400 Unionfs: copyup updates Fixes, updates, and better documentation for the file-copyup functionality. Include two additional utility functions useful for copyup code callers. Parent directory copyup updates: create_parents now takes a string name instead of the whole dentry. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 1d8d7cedd963dcb8be5db025679335a643109da9 Author: Erez Zadok Date: Mon Sep 3 19:53:02 2007 -0400 Unionfs: documentation updates Details of cache-coherency implementation (as per OLS'07 talk). Also explain new incgen support via remount, not ioctl. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit fdf03e91dd6443cc52de8b6858159645070fc8ca Author: Erez Zadok Date: Fri Aug 31 16:24:35 2007 -0400 Unionfs: cache-coherency and fixes for unionfs_rename Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit d5f8824353d116f2e3c12a7adf9c4bb3a97933af Author: Erez Zadok Date: Fri Aug 31 16:17:51 2007 -0400 Unionfs: cache-coherency - file flush Update our inode's time after flush. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 854355a64ffc322b6a57a1d86c27bc86809cb98c Author: Erez Zadok Date: Thu Sep 6 12:40:28 2007 -0400 Unionfs: cache-coherency - dentries Utility functions to check if lower dentries/inodes are newer than upper ones, and purging cached data if lower objects are newer. Also passed flag to our d_revalidate_chain, to tell it if the caller may be writing data or just reading it. [jsipek: changed purge_inode_data to take a struct inode] Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 8f97d7284666f688254eb0b7bb4b6234c9ed0ffd Author: Erez Zadok Date: Fri Aug 31 16:12:11 2007 -0400 Unionfs: cache-coherency - update inode times Part of cache-coherency support (as per OLS'07 talk and Documentation/filesystems/unionfs/concepts.txt): update our inode time if lower had changed. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 1baf37ff5a565c02edc51ac39cf946afda123b8a Author: Erez Zadok Date: Fri Aug 31 16:04:50 2007 -0400 Unionfs: cpp endif comments Add comments to #endif's to help clarify code. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 892863974598614d463e4f2e36ce5036bffa9b28 Author: Erez Zadok Date: Fri Aug 31 16:03:58 2007 -0400 Unionfs: copyright corrections and updates Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 768dded312a22f2ad2146537899b60262adb000c Author: Erez Zadok Date: Fri Aug 31 16:09:20 2007 -0400 Unionfs: do not use fsstack_copy_attr_all Unionfs needs a special fan-out version of fsstack_copy_attr_all, which is called unionfs_copy_attr_all. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 29e6840d4b7a15cc4e8a6b3ee6d41eb6e34b0e23 Author: Andrew Morton Date: Fri Aug 31 16:10:29 2007 -0400 Unionfs: fixed compilation error Signed-off-by: Andrew Morton Signed-off-by: Josef 'Jeff' Sipek commit ed5f8abe66f4f79bf12f8a0d97b2ebe3e7dcbdfe Author: Erez Zadok Date: Fri Aug 31 15:47:54 2007 -0400 VFS/fsstack: remove 3rd argument to fsstack_copy_attr_all Unionfs needs a special fan-out version of fsstack_copy_attr_all. A single-level stackable file systems such as eCryptfs can therefore use a simplified fsstack_copy_attr_all function; remove its 3rd argument, which was never used by eCryptfs and was only used by Unionfs. Acked-by: Michael Halcrow Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 02af11463402e5caff83f9f543efceade9d9322d Author: Erez Zadok Date: Fri Aug 31 15:34:45 2007 -0400 VFS: export release_open_intent symbol Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 273c1ecf93de07838e860eab3e7ccd862d5c620e Author: Josef 'Jeff' Sipek Date: Mon Jul 23 11:28:40 2007 -0400 Unionfs: Remove slab destructors from kmem_cache_create() Signed-off-by: Josef 'Jeff' Sipek commit 4fde783341e696a9a27c4fdc3e334faff8af6a0f Author: Erez Zadok Date: Fri Jul 20 23:36:11 2007 -0400 Unionfs: Set copied up open file mode to read-write When we copyup a file, we used to set the new file's open mode to write only. But we need read permission too. We need write permission because we're creating a new file; and we need read permission because the original file had to have been readable. If we don't set the new files permission to BOTH read and write, we get -EBADF when trying calling vfs_read/vfs_write on a copied up file. (This fix is somewhat related to unionfs_readpage fixes that use vfs_read instead of calling the lower readpage.) Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 452ae35d340235930afc87b74164809c2d76afbe Author: Erez Zadok Date: Sat Jul 21 21:03:39 2007 -0400 Unionfs: Rewrite do_unionfs_readpage to use vfs_read In do_unionfs_readpage, we used to call the lower file system's ->readpage. However, some file systems (e.g., tmpfs) don't implement ->readpage, causing a NULL pointer dereference under certain conditions, especially under severe memory pressure. This patch reimplements do_unionfs_readpage using vfs_read, which makes the code simpler and more reliable, as we depend on the VFS to do most of the hard work (even if this implementation might be a bit slower). This fix also makes sense because it makes the mmap code in unionfs more symmetric with unionfs_commit_write --- which uses vfs_write(). Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 4a69852d4e419312753338886d9caa11e3c44da0 Author: Erez Zadok Date: Fri Jul 20 23:34:28 2007 -0400 Unionfs: Fix minor typo in a comment Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 65d8ddf9c351ed11e9d4a7a444b65a39c7fef455 Author: Erez Zadok Date: Fri Jul 20 23:34:13 2007 -0400 Unionfs: Use splice_read file method instead of sendfile Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit bc95e6bba69a127383283d561ceac04f9a7b0237 Author: Erez Zadok Date: Fri Jul 20 23:33:29 2007 -0400 Unionfs: Fix renaming symlinks on readonly branches bug Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit ef580e2647d6fdfcb655e197d3bcf2bc8858f853 Author: Erez Zadok Date: Fri Jul 20 23:32:49 2007 -0400 Unionfs: Prevent deadlock with branch-management code Don't grab the superblock read-lock in unionfs_permission, which prevents a deadlock with the branch-management "add branch" code (which grabbed the write lock). It is safe to not grab the read lock here, because even with branch management taking place, there is no chance that unionfs_permission, or anything it calls, will use stale branch information. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 1ddb4f0c3f777ebf5bc09527c22b940af72a3576 Author: Adrian Bunk Date: Mon Jul 2 14:27:57 2007 -0400 [PATCH] unionfs: make functions static This patch makes some needlessly global functions static. Signed-off-by: Adrian Bunk Signed-off-by: Josef 'Jeff' Sipek commit 4dbd7117049dd367949a3e642e6306211a8b5b8d Author: Erez Zadok Date: Fri Jun 29 02:02:11 2007 -0400 Unionfs: Remove unnecessary BUG_ON in unionfs_follow_link Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 6ed075f8aaba00090a6f1edd6180c9448d0854a7 Author: Erez Zadok Date: Fri Jun 29 02:03:17 2007 -0400 Unionfs: Clarification comment for unionfs_lookup Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 8e5310a5a2bd48e26ed505fdfcdbf542f3e0dcf4 Author: Erez Zadok Date: Fri Jun 29 01:49:08 2007 -0400 Unionfs: Use file->f_path instead of file->f_dentry Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit b0d0c03f3e2b56be6ad42a88842950412fd89f22 Author: Josef 'Jeff' Sipek Date: Fri Jun 29 01:53:16 2007 -0400 Unionfs: Add missing unlock call in unionfs_file_release Signed-off-by: Josef 'Jeff' Sipek commit 54473bef1026c30156f33dae64055ee9e45e6af1 Author: Erez Zadok Date: Mon Jul 23 15:26:18 2007 -0400 Unionfs: Convert all instances of "hidden" to "lower" The Unionfs code contained many references to symbols whose name had the string "hidden" in it, referring to, for example, a "hidden inode" below the Unionfs inode. The term "hidden" was there for historical reasons and was a misnomer, implying that the objects at Unionfs's lower branches were somehow hidden or unavailable. This was not just incorrect, but confusing. The lower objects are just that: lower. They are not hidden from users. In fact, users can 'cd' to lower branches and manipulate files directly there. This long patch renames all such mis-named symbols, and re-indents the code as needed to comply with coding standards. [jsipek: fixed up few rejects] Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 2aa1f8883eb8da800892c955b77f0e3d4b43b604 Author: Josef 'Jeff' Sipek Date: Fri Jun 8 11:08:33 2007 -0400 Unionfs: Remove superfluous check for NULL pointer Since we use containers and the struct inode is _inside_ the unionfs_inode_info structure, UNIONFS_I will always (given a non-NULL inode pointer), return a valid non-NULL pointer. Signed-off-by: Josef 'Jeff' Sipek commit e8a91805f7c08296dda2eb418d301086734ae442 Author: Josef 'Jeff' Sipek Date: Fri Jun 8 17:04:40 2007 -0400 Unionfs: Change the semantics of sb info's rwsem This rw semaphore is used to make sure that a branch management operation... 1) will not begin before all currently in-flight operations complete 2) any new operations do not execute until the currently running branch management operation completes TODO: rename the functions unionfs_{read,write}_{,un}lock() to something more descriptive. Signed-off-by: Josef 'Jeff' Sipek commit 75a937ea98b8aece05f11abd3369b0d873d6823f Author: Josef 'Jeff' Sipek Date: Fri Jun 8 10:58:21 2007 -0400 Unionfs: Add BUG_ONs to unionfs_lower_* Signed-off-by: Josef 'Jeff' Sipek commit 3e3a8666f04e98faf4574dd4339d3e80e8a9961a Author: Josef 'Jeff' Sipek Date: Fri Jun 8 10:58:22 2007 -0400 Unionfs: Change free_dentry_private_info to take a struct dentry This makes it more symmetric with new_dentry_private_info. Signed-off-by: Josef 'Jeff' Sipek commit 96ac35ac6377f7c10821b6b678dd73de4a2df755 Author: Josef 'Jeff' Sipek Date: Fri Jun 8 10:58:24 2007 -0400 Unionfs: Cleanup new_dentry_private_data Signed-off-by: Josef 'Jeff' Sipek commit fcc3343d56ccf048255d874fa653c04e1ae1d231 Author: Erez Zadok Date: Fri Jun 8 10:39:11 2007 -0400 Unionfs: Revalidate dentries passed to all inode/super operations Be sure to properly revalidate all dentry chains passed to all inode and super_block operations. Remove the older BUG_ON test is_valid_dentry(). This should help improve cache-coherency. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 7045df24893adc02ca12a80951cd05a4a192d730 Author: Erez Zadok Date: Fri Jun 8 10:36:23 2007 -0400 Unionfs: merge find_new_branch_index and branch_id_to_idx into one function Useful code cleanup and consolidation between the ODF code and non-ODF code. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit a3b997e5e4624706d5b0519d1ff9a16f6e1a4903 Author: Yiannis Pericleous Date: Fri Jun 8 10:29:29 2007 -0400 Unionfs: mmap implementation Signed-off-by: Shaya Potter Signed-off-by: Erez Zadok Signed-off-by: Yiannis Pericleous Signed-off-by: Josef 'Jeff' Sipek commit 8041b4466f003a617a8ced961795739211d1d986 Author: Erez Zadok Date: Thu Jun 7 17:42:59 2007 -0400 Unionfs: Remove unnecessary #define UNIONFS_TMPNAM_LEN is used in only one place, and we have calculate the length of the string to begin with. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit a79a635ccbfdc8bd8ec061d0bcda2416be8bdf8e Author: Erez Zadok Date: Thu Jun 7 17:41:10 2007 -0400 Unionfs: Add standard copyright comment to include/linux/union_fs.h Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit a6162c920928f076bef4e3ee47bd0e7c6342d499 Author: Erez Zadok Date: Thu Jun 7 17:40:22 2007 -0400 MAINTAINERS: Add Erez Zadok as a maintainer of Unionfs Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 18353bc9c1c6f0853d42f89311e3af748ac1bd99 Author: Erez Zadok Date: Thu Jun 7 17:28:37 2007 -0400 Unionfs: call statfs on lower file system properly Get the correct lower dentry to use to statfs the first branch (always), Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit f9871259c6ae1e6279d3c193b6ce9868526486e2 Author: Erez Zadok Date: Thu Jun 7 17:45:12 2007 -0400 Unionfs: Set lower inodes correctly after branch management succeeds Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 996a0e01cc94549d6ade0e3cd9d0ec9cab99fbf0 Author: Erez Zadok Date: Thu Jun 7 17:05:07 2007 -0400 Unionfs: Retry lookup for different silly-renamed files When we have to copyup an open-but-unlinked file, we have to give it a temporary name, similar to NFS's silly-renamed files. So we generate temporary file names until we find one that doesn't exist, and use it. The code had a bug where if the silly-renamed file name already existed, Unionfs would oops upon copyup to that temp name. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 73cda5ed00515bddea7bcc9f1a4b13d57e0dc5c6 Author: Erez Zadok Date: Thu Jun 7 17:05:00 2007 -0400 Unionfs: Don't revalidate dropped dentries This fixes a harmless but annoying message that unionfs prints if a dropped dentry is being revalidated, which could happen if you unlink open files. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 78dae7f5e8cd59cdd931368995dfa6b3513522fb Author: Randy Dunlap Date: Wed Jun 6 20:38:19 2007 -0400 [PATCH] unionfs section mismatch Fix section marker in header file: WARNING: fs/unionfs/unionfs.o(.init.text+0x56): Section mismatch: reference to .exit.text:stop_sioq (between 'init_module' and 'init_sioq') Signed-off-by: Randy Dunlap Signed-off-by: Josef 'Jeff' Sipek commit bbdd40631fff710da751a2dff6568b011deaff7a Author: Josef 'Jeff' Sipek Date: Sun Jun 3 22:06:33 2007 -0400 Unionfs: Fix lock leak in unionfs_ioctl Signed-off-by: Josef 'Jeff' Sipek commit c92e6b778776b2fe6edf61c497bdf441269c4f2f Author: Erez Zadok Date: Wed May 23 18:27:24 2007 -0400 Unionfs: Correctly decrement refcounts of mnt's upon branch management The old logic was broken in one place, which another place tried to "fix" incorrectly. Also added detailed comments to explain the new/correct logic. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 8c5928bbcfd900422f4ce29ea691a3946c309345 Author: Yiannis Pericleous Date: Wed May 23 18:25:47 2007 -0400 Unionfs: Removed a trailing whitespace Signed-off-by: Yiannis Pericleous Signed-off-by: Josef 'Jeff' Sipek commit eb1936047a8124290c55b7e58446673d331c29a6 Author: Josef 'Jeff' Sipek Date: Wed May 23 19:51:47 2007 -0400 Unionfs: Actually catch bad use of unionfs_mnt{get,put} Signed-off-by: Josef 'Jeff' Sipek commit 215844d43ffc48a01a49a5cd8178b90aa8b1284a Author: Erez Zadok Date: Wed May 23 17:57:31 2007 -0400 Unionfs: Remove defunct unionfs_put_inode super op Removed old workaround code that was needed to get mmap working, is no longer needed with recent kernels. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 341979835556f9aaa58e30ae98690825cd6cf0cc Author: Erez Zadok Date: Wed May 23 17:55:28 2007 -0400 Unionfs: Documentation update regarding overlapping branches and new lookup code Added detailed comment and updated documentation to explain why overlapping branches are disallowed, and better explain the cache coherency issues. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit fa1add96b50b0080d381ef2f8bc019584485a630 Author: Erez Zadok Date: Wed May 23 17:48:11 2007 -0400 Unionfs: Disallow setting leftmost branch to readonly Unionfs requires the leftmost branch to be writeable for copyup to work properly and simply. If, through branch-management commands (add, delete, or mode change), the leftmost branch will becomes readonly, then return an error (and tell the user to use "remount,ro" if they want a readonly union). [jsipek: fixed up to apply cleanly] Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 42ca33f812f0f2c1ebab6f7302276618ec6090c9 Author: Josef 'Jeff' Sipek Date: Wed May 23 17:17:31 2007 -0400 Unionfs: Use krealloc instead of open-coding the functionality Change the branch management code to use krealloc instead of playing tricks with kmalloc/memcpy/kfree. Signed-off-by: Josef 'Jeff' Sipek commit bb0bd8b25179ddcaf78ea25cc27705df7b16d353 Author: Josef 'Jeff' Sipek Date: Wed May 23 17:06:08 2007 -0400 Unionfs: Call realloc unconditionally krealloc already checks if the new size is greater than the old size. Therefore, we can call realloc unconditionally - making the code simpler and cleaner. Signed-off-by: Josef 'Jeff' Sipek commit c99cc0bc2937849fb837d4da357580aa45aa10ef Author: Josef 'Jeff' Sipek Date: Wed May 23 16:44:54 2007 -0400 Unionfs: Don't leak resources when copyup fails partially Original-patch-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit a1f61849ce1ec5625a32ac1d1e3b7bed75a58489 Author: Erez Zadok Date: Wed May 23 16:33:24 2007 -0400 Unionfs: Prefix external functions with 'extern' properly Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 5fe694dc682dcf883a288b09300828322c8cf3a6 Author: Josef 'Jeff' Sipek Date: Wed May 23 16:25:21 2007 -0400 Unionfs: Combine unionfs_write with __unionfs_write. The __unionfs_write helper function was used only by unionfs_write, and there is really no reason why they should not be combined. Signed-off-by: Josef 'Jeff' Sipek commit 2c71f9ad87aeddec15b57e545a4c59dcca93e442 Author: Josef 'Jeff' Sipek Date: Sun May 20 17:12:48 2007 -0400 Unionfs: Move unionfs_query_file to commonfops.c Moved unionfs_query_file closer to its one user in commonfops.c. Additionally, it can now become static, and branchman.c can be removed as it is empty. Signed-off-by: Josef 'Jeff' Sipek commit e8d5ac4225653382a749c07b1a90e10a8f1c0142 Author: Erez Zadok Date: Sun May 20 16:44:52 2007 -0400 Unionfs: Rename our "do_rename" to __unionfs_rename To avoid confusion with the VFS function do_rename, and to help ctags, rename our utility (static) function do_rename to __unionfs_rename. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 552cf97158a3f930be4d9ce3d536cf44233806f3 Author: Erez Zadok Date: Sun May 20 16:23:01 2007 -0400 Unionfs: Rename Unionfs's double_lock_dentry to avoid confusion To avoid potential confusion with a VFS function, rename our version of double_lock_dentry to unionfs_double_lock_dentry. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 6aa7d08edea1d2f736dce15079587173e548b302 Author: Erez Zadok Date: Sun May 20 16:03:00 2007 -0400 Unionfs: Consistent pointer declaration spacing Change instances of "foo * var" to "foo *var" for consistency. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit ddb100df16a2411166ac67600328d333f5ab11d2 Author: Erez Zadok Date: Sun May 20 16:46:21 2007 -0400 Unionfs: Added numerous comments Audited entire code for documentation. Added comments at top of functions where it felt necessary (i.e., function's name and size don't make it clear what it may be doing precisely). Reformatted some long comments. Fixed a few comment typos and spelling errors. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 4c83ecfdb9271048f7341d70bd884e4e476650a0 Author: Erez Zadok Date: Mon Jul 23 15:19:58 2007 -0400 Unionfs: Cleanup of strings and comments Includes: - consistent style for multi-line comments - spell-check of all strings and comments Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit b4c75c7af385e82d45e7b3cd95a4d90931881a56 Author: Erez Zadok Date: Sun May 20 15:21:08 2007 -0400 Unionfs: Add missing copyright notices Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit f8a97d46cf2638f0903df12425db3dcefab33ab8 Author: Erez Zadok Date: Sun May 20 15:36:32 2007 -0400 Unionfs: Every printk should prefix with "unionfs: " consistently Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 010e768218b3c1d612be04ae1b73ed9b7a7c61fd Author: Erez Zadok Date: Mon Jul 23 15:18:35 2007 -0400 Unionfs: Coding style fixes Includes: - indentation fixes - 80 column wrapping - removing unnecessary braces - removing trailing whitespace Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 305a81226029295d5d7bc7463ba029b0ea41394c Author: Erez Zadok Date: Sun May 20 15:18:38 2007 -0400 Unionfs: Tiny documentation fixups Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit a1af1be82628b515d403073d57dfd4ff8ab6b671 Author: Josef 'Jeff' Sipek Date: Sat May 19 03:14:30 2007 -0400 Unionfs: SLAB_CTOR_CONSTRUCTOR has been removed from vanilla Signed-off-by: Josef 'Jeff' Sipek commit f87961a331d3ed6e3b440e4ea8f67420175bc77d Author: Pekka Enberg Date: Sun May 13 12:55:44 2007 -0400 [PATCH] unionfs: fix slab abuses with krealloc This changes unionfs to use krealloc() for reallocating memory so that we don't need to play tricks with slab internals. Cc: Josef Sipek Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Josef 'Jeff' Sipek commit d05f56aa4686a9318094e3e85768cf38a60f6099 Author: Adrian Bunk Date: Sat May 5 15:28:33 2007 -0400 [PATCH] fix unionfs compilation On Sat, May 05, 2007 at 01:49:55AM -0700, Andrew Morton wrote: >... > Changes since 2.6.21-rc7-mm2: >... > git-unionfs.patch >... > git trees >... <-- snip --> ... CC fs/unionfs/super.o /home/bunk/linux/kernel-2.6/linux-2.6.21-mm1/fs/unionfs/super.c: In function ‘init_once’: /home/bunk/linux/kernel-2.6/linux-2.6.21-mm1/fs/unionfs/super.c:822: error: ‘SLAB_CTOR_VERIFY’ undeclared (first use in this function) /home/bunk/linux/kernel-2.6/linux-2.6.21-mm1/fs/unionfs/super.c:822: error: (Each undeclared identifier is reported only once /home/bunk/linux/kernel-2.6/linux-2.6.21-mm1/fs/unionfs/super.c:822: error: for each function it appears in.) make[3]: *** [fs/unionfs/super.o] Error 1 <-- snip --> Signed-off-by: Adrian Bunk Signed-off-by: Josef 'Jeff' Sipek commit d4868a8a1727b52dde14f3869062dd7a6b0b0959 Author: Adrian Brunyate Date: Thu Apr 26 18:51:16 2007 -0400 Unionfs: Check remount options for being NULL Signed-off-by: Adrian Brunyate Signed-off-by: Josef 'Jeff' Sipek commit 0c0e00f5376669fe7a0ae5a377806fa8b9b89038 Author: Adrian Brunyate Date: Thu Apr 26 18:51:09 2007 -0400 Unionfs: Accept MS_SILENT during remount [jsipek: whitespace cleanup] Signed-off-by: Adrian Brunyate Signed-off-by: Josef 'Jeff' Sipek commit 70f6fa1110d8c61565f3389f2b36bb87ed9bfef7 Author: Erez Zadok Date: Fri Mar 23 13:10:46 2007 -0400 Unionfs: Don't inline do_remount_{add,del,mode}_option gcc4 decided to inline do_remount_{add,del,mode}_option creating an 600 byte stack abuser on a x86_64 test box. Reported by: Josef 'Jeff' Sipek Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 7fe1826b13ce6b26f3c4ee358e6df38eae60a1d8 Author: Erez Zadok Date: Fri Mar 23 13:07:14 2007 -0400 Unionfs: Added several BUG_ONs to assert dentry validity This should help catch races between the VFS and the branch-management code. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 90e6e8a6f563c1a59b062f4810212c53102c9400 Author: Erez Zadok Date: Thu Mar 22 20:17:48 2007 -0400 Unionfs: Properly handle stale inodes passed to unionfs_permission Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 09cfe1913bab9a343d9c0135e1eaf8601890a653 Author: Erez Zadok Date: Thu Mar 22 20:09:07 2007 -0400 Unionfs: Pass lowernd to lower ->revalidate function Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit a2e31679c70849041bf380aa9b1e2c2d648d89f8 Author: Erez Zadok Date: Thu Mar 22 20:08:30 2007 -0400 Unionfs: vfsmount reference counting fixes Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 3354b2273096f65d41e5a37ed751acd70f0a794c Author: Erez Zadok Date: Thu Mar 22 20:01:56 2007 -0400 Unionfs: unionfs_create needs to revalidate the dentry We have to read-lock the superblock rwsem, and we have to revalidate the parent dentry and this one. A branch-management operation could have taken place, mid-way through a VFS operation that eventually reaches unionfs_create(). So we have to ensure consistency, just as we do with the file operations. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit e8b97d5488437c5b159aea14e816671462d921e7 Author: Erez Zadok Date: Thu Mar 22 19:47:43 2007 -0400 Unionfs: Decrement totalopens counter on error in unionfs_open Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 469ae5d5d604f5bf0f63b0cf9ab3ea73b80a4216 Author: Josef 'Jeff' Sipek Date: Sun Mar 18 16:30:45 2007 -0400 Unionfs: Document unionfs_d_release locking Signed-off-by: Josef 'Jeff' Sipek commit 91645096a3ca86187a87db0dd3dec88a60cec911 Author: Josef 'Jeff' Sipek Date: Sun Mar 18 16:22:03 2007 -0400 Unionfs: Remove the older incgen ioctl The new remount code now has the "incgen" functionality. Signed-off-by: Josef 'Jeff' Sipek commit d890d8023cedff562a4e11b145448180b642435a Author: Erez Zadok Date: Thu Mar 22 19:32:40 2007 -0400 Unionfs: Grab the unionfs sb private data lock around branch info users Locking/concurrency/race fixes. Use the unionfs superblock rwsem, and grab the read lock around every op that uses branch-related information, such as branch counters. Grab the write rwsem lock in operations which attempt to change branch information, such as when adding/deleting branches. This will, for example, cause branch-management remount commands (which are infrequent) to block a bit until all in-progress file operations on open files are done. Signed-off-by: Erez Zadok [jsipek: whitespace fixes & more locks/unlocks] Signed-off-by: Josef 'Jeff' Sipek commit 0466840723b91a6c509b42274f0c493ef895b97c Author: Erez Zadok Date: Mon Mar 19 21:02:55 2007 -0400 Unionfs: Rewrite unionfs_d_revalidate Rewrite unionfs_d_revalidate code to avoid stack-unfriendly recursion: split into a call to revalidate just one dentry, and an interative driver function to revalidate an entire dentry-parent chain. Fix vfsmount ref leaks which prevented lower f/s from being unmounted after generation increment, esp. during heavy loads. Fix one deadlock between revalidation code and VFS. Better documentation of what the code does. Signed-off-by: Erez Zadok [jsipek: compile & whitespace fixes] Signed-off-by: Josef 'Jeff' Sipek commit 46e7fc9364ff54729d05f439c0e53143bb20b6c3 Author: Erez Zadok Date: Mon Mar 19 20:57:49 2007 -0400 Unionfs: Introduce unionfs_mnt{get,put} Helper inline functions to perform Unionfs's mntget/put ops on lower branches. Signed-off-by: Erez Zadok [jsipek: cleanup branching in unionfs_mnt{get,put} and compile fixes] Signed-off-by: Josef 'Jeff' Sipek commit 2d9120f87b59a311e9159eaa6f6ed9a652417cbe Author: Erez Zadok Date: Mon Mar 19 20:44:12 2007 -0400 Unionfs: Bulk of branch-management remount code Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 73390fcf27e245a8195cb704805cb05c2fe098a3 Author: Erez Zadok Date: Thu Mar 22 19:43:29 2007 -0400 Unionfs: Introduce branch-id code Each branch gets a unique ID, which helps during branch additions, deletions, and changes, to locate where branches were moved to, and perform proper reference-counting. This is useful even if the same directory was added more than once to union. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit e6c494517fa73957345165025053e1d3f84cb226 Author: Erez Zadok Date: Mon Apr 9 09:57:51 2007 -0400 Unionfs: Actually verify if dentry's info node is locked Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 248bdde1b64b99aaf0b8a7c428a2a40827e0d930 Author: Erez Zadok Date: Mon Mar 19 03:01:49 2007 -0400 Unionfs: Provide more helpful info on branch leaks during unmount Signed-off-by: Erez Zadok [jsipek: no need to take a read lock on the superblock private data] Signed-off-by: Josef 'Jeff' Sipek commit d80016709014588c705506d21dc8ca198c11bb4b Author: Erez Zadok Date: Mon Mar 19 00:46:03 2007 -0400 Unionfs: Rename unionfs_data sbcount field to more appropriate open_files Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit cb446dd863bde68397f3cf23c1c1a7e442d99f9d Author: Josef 'Jeff' Sipek Date: Sun Mar 18 19:37:51 2007 -0400 Unionfs: Proper comment on rwsem field Signed-off-by: Josef 'Jeff' Sipek commit 5742bd8c8199047d90e2b78f677d23b6199ae336 Author: Erez Zadok Date: Fri Mar 23 17:17:07 2007 -0400 Unionfs: Documentation updates for branch-management Describe dynamic branch-management introduced by subsequent patches. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 54db4771ee4d836f4563a0a64abe671389076a59 Author: Erez Zadok Date: Wed May 23 20:39:35 2007 -0400 fs: Export drop_pagecache_sb symbol Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 58fe7c171f4b7b94122e2a4d51f49a8c99d9e727 Author: Erez Zadok Date: Wed May 23 20:42:50 2007 -0400 fs: Introduce path{get,put} Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 960ab76a9a5ed8894c146369e52146f702bbb7a3 Author: Randy Dunlap Date: Mon Mar 19 19:15:22 2007 -0400 [PATCH] Unionfs: sioq not __exit stop_sioq() is called from both __init and __exit functions, so it shouldn't be marked __exit. Reported on the kernelnewbies mailing list, but no patch offered there. Signed-off-by: Randy Dunlap Signed-off-by: Josef 'Jeff' Sipek commit ba3bc9ce303f7b486e20a9ed14bebdb239b0bc86 Author: Josef 'Jeff' Sipek Date: Sat Mar 17 19:42:25 2007 -0400 MAINTAINERS: Unionfs URL update Signed-off-by: Josef 'Jeff' Sipek commit 07302e099bd2f6e7a934be9dfce10e77c3c97ebf Author: Erez Zadok Date: Sun Mar 4 18:02:11 2007 -0500 fs/unionfs/: Fix unlocking in error paths Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 079e33558080b69ba51ced4c88f56b6036b571dc Author: Erez Zadok Date: Sun Mar 4 15:21:14 2007 -0500 fs/unionfs/: Fix dentry leak in copyup_named_dentry When we chmod a directory on a readonly branch, and have to copy it up, we forget to dput(). If this was a file, it gets dput indirectly through other functions we call, but not if it was a directory. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 3a5ca19e6b4c9b98108bea1460a9469d57f6d9e8 Author: Erez Zadok Date: Fri Mar 2 13:10:56 2007 -0500 fs/unionfs/: mntput in __cleanup_dentry This fixes a mnt refleak which occured during copyup when directory hierarchy was recreated on a writable branch. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 2a5d0333bd35afbd88fd8d21277116afe43407e5 Author: Erez Zadok Date: Sun Mar 4 00:41:51 2007 -0500 fs/unionfs/: Fix copyup_deleted_file dentry leak Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 7157678f5b34e921675648ae3c6b17dd652596b3 Author: Josef 'Jeff' Sipek Date: Fri Mar 2 13:14:01 2007 -0500 fs/unionfs/: Miscellaneous coding style fixes Signed-off-by: Josef 'Jeff' Sipek commit 6aadcf2296a3af037892aeab9a8d6a8b60f4dd35 Author: Josef 'Jeff' Sipek Date: Tue Feb 27 14:27:25 2007 -0500 fs/unionfs/: Check return value of d_path Signed-off-by: Josef 'Jeff' Sipek commit d71c0d90773fafc6907be9f38d232c907172ec61 Author: Josef 'Jeff' Sipek Date: Sun Feb 25 17:32:46 2007 -0500 fs/unionfs/: Use SEEK_{SET,CUR} instead of hardcoded values Signed-off-by: Josef 'Jeff' Sipek commit cb692a9616005307155d648ea316520b89b51678 Author: Josef 'Jeff' Sipek Date: Sun Feb 25 17:30:34 2007 -0500 fs/unionfs/: Remove alloc_filldir_node alloc_filldir_node was used only once. Additionally, all the arguments passed to it were ignored wasting stack space for no reason whatsoever. Signed-off-by: Josef 'Jeff' Sipek commit e4284cd73ddfe6911347b45ac3f7fe944adfa79c Author: Josef 'Jeff' Sipek Date: Sat Feb 24 16:47:45 2007 -0500 fs/unionfs/: Rename unionfs_d_revalidate_wrap Follow the convention of "foo" calling "__foo". Signed-off-by: Josef 'Jeff' Sipek commit ff7ad2019691df40ff6c97ae2788c0a789031289 Author: Josef 'Jeff' Sipek Date: Sat Feb 24 16:46:08 2007 -0500 fs/unionfs/: Several small cleanups in unionfs_interpose 1) No need to lock the inode - lockdep was complaining about potential circular dependency 2) No need to use temporary variable for iunique() inode number 3) Removed unneeded comment Signed-off-by: Josef 'Jeff' Sipek commit 7966756c7edc5a0d93fdbfc180c4959553af1dc5 Author: Josef 'Jeff' Sipek Date: Fri Feb 23 01:04:09 2007 -0500 fs/unionfs/: Don't grab dentry private data mutex in unionfs_d_release Grabbing the UNIONFS_D(dentry)->lock is completely unnecessary and there are no other references; we are about to free the object anyway. Additionally, grabbing the mutex produces warning when the slab object is reused - as it was freed while there still was a reference to it. Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 8676ef3c2c9c14a300b4738c1f148b4fffeebc41 Author: Erez Zadok Date: Fri Mar 2 13:35:33 2007 -0500 fs/unionfs/: Fix a memory leak in unionfs_read_super Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit e9fb861a1c3a7523bc8960ebbb1dd8cf5928effa Author: Erez Zadok Date: Fri Mar 2 13:00:57 2007 -0500 fs/unionfs: Fix a memory leak & null pointer dereference Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit cc794ffdaef6e94b911b4af12b5ec9d9d3753d7d Author: Adrian Bunk Date: Wed Feb 21 01:30:10 2007 -0500 [PATCH] UNION_FS must depend on SLAB On Sat, Feb 17, 2007 at 09:51:46PM -0800, Andrew Morton wrote: >... > Changes since 2.6.20-mm1: >... > git-unionfs.patch >... > git trees >... <-- snip --> ... CC fs/unionfs/copyup.o /home/bunk/linux/kernel-2.6/linux-2.6.20-mm2/fs/unionfs/copyup.c: In function 'create_parents_named': /home/bunk/linux/kernel-2.6/linux-2.6.20-mm2/fs/unionfs/copyup.c:620: error: 'malloc_sizes' undeclared (first use in this function) /home/bunk/linux/kernel-2.6/linux-2.6.20-mm2/fs/unionfs/copyup.c:620: error: (Each undeclared identifier is reported only once /home/bunk/linux/kernel-2.6/linux-2.6.20-mm2/fs/unionfs/copyup.c:620: error: for each function it appears in.) make[3]: *** [fs/unionfs/copyup.o] Error 1 <-- snip --> Signed-off-by: Adrian Bunk Signed-off-by: Josef 'Jeff' Sipek commit 9b8cde5f1f390bfd6966c7ca837c64812179195f Author: Josef 'Jeff' Sipek Date: Sat Feb 17 03:25:15 2007 -0500 fs/unionfs/: Remove unused structure members & macros This patch removes: - hidden_mnt pointer from struct unionfs_data - mount_flag from struct unionfs_sb_info - mount_flag related macros Signed-off-by: Josef 'Jeff' Sipek commit 46c46d2c93ed2a192bd073a259c57cf7d1006928 Author: Erez Zadok Date: Mon Feb 12 12:36:38 2007 -0500 Unionfs: Documentation update Be little gentler & updated the URLs Signed-off-by: Erez Zadok Signed-off-by: Josef 'Jeff' Sipek commit 6006c7db0bad2803b2de8274cf6aa2e63c6067c8 Author: Josef 'Jeff' Sipek Date: Mon Feb 19 23:35:32 2007 -0500 fs/: Move eCryptfs & Unionfs config options into a sub-menu Using The Misc filesystems sub-menu for layered/stackable filesystems only makes it harder for users to find eCryptfs/Unionfs. Additionally, the menu can be easily turned into a menuconfig, which could be used to turn on any VFS/VM functionality required by layered filesystems (there is none at the moment). Signed-off-by: Josef 'Jeff' Sipek Signed-off-by: Michael Halcrow commit 2d2a1cac9abdfc3637b04de52c967ffb0207bd92 Author: Josef 'Jeff' Sipek Date: Thu Feb 1 12:14:03 2007 -0500 fs/unionfs/: Use __roundup_pow_of_two instead of custom rounding code Signed-off-by: Josef 'Jeff' Sipek commit 48e2222d54bce303dd03b4f7ad181812a5f1e05e Author: Josef 'Jeff' Sipek Date: Sun Jan 28 14:20:19 2007 -0500 fs/unionfs/: Don't duplicate the struct nameidata The only fields that we have to watch out for are the dentry and vfsmount. Additionally, this makes Unionfs gentler on the stack as nameidata is rather large. Signed-off-by: Josef 'Jeff' Sipek commit d5a0f64d345c374b068e896bc9ca743380366f2d Author: Josef 'Jeff' Sipek Date: Sun Jan 28 14:20:49 2007 -0500 fs/unionfs/: Andrew Morton's comments - rename {,un}lock_dentry to unionfs_{,un}lock_dentry - few minor coding style fixes - removed prototypes from .c files - replaced dbstart macros etc with static inlines - replaced UNIONFS_D(d)->sem semaphore with a mutex - renamed sioq struct workqueue to superio_workqueue - made unionfs_get_nlinks and alloc_whname not inlined Signed-off-by: Josef 'Jeff' Sipek commit 07ceebc0bca5e051e034ba9c1ebc828f1e4ee3b9 Author: Adrian Bunk Date: Thu Jan 25 03:15:59 2007 -0500 fs/unionfs/: possible cleanups This patch contains the following possible cleanups: - every function should #include the headers containing the prototypes of it's global functions - static functions in C files shouldn't be marked "inline", gcc should know best when to inline them - make needlessly global code static - #if 0 the following unused global function: - stale_inode.c: is_stale_inode() Signed-off-by: Adrian Bunk [removed stale inode related fixes as stale_inode.c is gone] Signed-off-by: Josef 'Jeff' Sipek commit 029e0fbcc605a4cb21742c7666ad7d7c47724879 Author: Josef 'Jeff' Sipek Date: Sun Jan 28 15:52:43 2007 -0500 fs/unionfs/: Remove stale_inode.c The stale inode operations were heavily based on bad inode operations. This patch removes stale_inode.c and converts all users of stale_inode_ops to bad_inode_ops as there seems to be no reason to return ESTALE instead of EIO. This is the more appropriate than porting the bad_inode.c fix (commit be6aab0e9fa6d3c6d75aa1e38ac972d8b4ee82b8) to stale_inode.c. Signed-off-by: Josef 'Jeff' Sipek commit 0aeef50c5f4c3b5a6a8e5ecf93f4418e7fca63a4 Author: Josef "Jeff" Sipek Date: Sun Jan 28 15:11:23 2007 -0500 Unionfs: Extended Attributes support Extended attribute support. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 756d500ad2427290c58c304a0176bc8cf7bf7d67 Author: Josef "Jeff" Sipek Date: Sun Jan 28 15:10:20 2007 -0500 Unionfs: Kconfig and Makefile This patch contains the changes to fs Kconfig file, Makefiles, and Maintainers file for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit c9da41822b76681906a4eabff68607293539d275 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:47:57 2007 -0500 Unionfs: Unlink This patch provides unlink functionality for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit e9606b6463dc0fb84d8fe47e88863a5d2187777f Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:47:43 2007 -0500 Unionfs: Include file Global include file - can be included from userspace by utilities. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 8c432d0f4c29275cef8b96865dd690354b3d6156 Author: Josef "Jeff" Sipek Date: Sun Jan 28 15:05:29 2007 -0500 Unionfs: Internal include file This patch contains an internal Unionfs include file. The include file is specific to kernel code only, and therefore is separate from include/linux/unionfs.h. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit bf48a00f9ba44bbc678279d3862a971f6709f24e Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:46:56 2007 -0500 Unionfs: Helper macros/inlines This patch contains many macros and inline functions used thoughout Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit c02bddfb26818e9e8d91afc2da9dd93291dab2e4 Author: Josef "Jeff" Sipek Date: Sun Jan 28 15:05:07 2007 -0500 Unionfs: Handling of stale inodes Provides nicer handling of stale inodes. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit ee462f9b74787760fe78251401515181269ffbff Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:46:47 2007 -0500 Unionfs: Superblock operations This patch contains the superblock operations for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 19e682daa3f79c16f2a80ec1e1bcd6b240a02de6 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:46:39 2007 -0500 Unionfs: Miscellaneous helper functions This patch contains miscellaneous helper functions used thoughout Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 25532091260778fa408665ea5a5efd4c67de3671 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:46:11 2007 -0500 Unionfs: Privileged operations workqueue Workqueue & helper functions used to perform privileged operations on behalf of the user process. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 9315b8400c0da596350850d3e33a7e593e80ebda Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:45:56 2007 -0500 Unionfs: Rename This patch provides rename functionality for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 0d27e6744426acb6cabb334d6fc79cf906969626 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:45:48 2007 -0500 Unionfs: Readdir state This file contains the routines for maintaining readdir state. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 94f0af68ff56161f19b2d30f4e79107ccbfef84e Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:45:28 2007 -0500 Unionfs: Main module functions Module init & cleanup code, as well as interposition functions. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 4c086c6b85804bc1d6c951740631205ef1b837b8 Author: Josef "Jeff" Sipek Date: Mon Jul 23 15:13:25 2007 -0400 Unionfs: Lookup helper functions This patch provides helper functions for the lookup operations in Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit bb1b4211426b69f83573cf93b4c0901698d94187 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:44:54 2007 -0500 Unionfs: Inode operations This patch provides the inode operations for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 9d8ed06ac7b803e0c89d863c0b2e2773911bf6d3 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:44:35 2007 -0500 Unionfs: Directory manipulation helper functions This patch contains directory manipulation helper functions. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 681c6908a43187c59342967ac7ff7d63bf8ff0e2 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:44:24 2007 -0500 Unionfs: Directory file operations This patch provides directory file operations. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 8c93e23f5c007583120c942992f759423996c918 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:44:05 2007 -0500 Unionfs: File operations This patch provides the file operations for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit fd31be4df195dddf08e3a7071efd9f8c466b73b7 Author: Josef "Jeff" Sipek Date: Sun Jan 28 15:05:21 2007 -0500 Unionfs: Dentry operations This patch contains the dentry operations for Unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 40f5ce8f99198bbace3dd98c30575dfc6f44e2e8 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:42:32 2007 -0500 Unionfs: Copyup Functionality This patch contains the functions used to perform copyup operations in unionfs. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 0ec26e2f6f5c72726404f8a51a7802fdf827f7d4 Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:42:16 2007 -0500 Unionfs: Common file operations This patch contains helper functions used through the rest of the code which pertains to files. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit c77046445d2e5ba7e200ad2d578d67bdc3920fad Author: Josef "Jeff" Sipek Date: Sun Jan 21 18:42:01 2007 -0500 Unionfs: Branch management functionality This patch contains the ioctls to increase the union generation and to query which branch a file exists on. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok commit 367225a9dc2e35afeda1a9240ebe68b01817ab0a Author: Josef "Jeff" Sipek Date: Mon Feb 19 23:31:35 2007 -0500 Unionfs: Documentation This patch contains documentation for Unionfs. You will find several files outlining basic unification concepts and rename semantics. Signed-off-by: Josef "Jeff" Sipek Signed-off-by: David Quigley Signed-off-by: Erez Zadok Signed-off-by: Andrew Morton --- Documentation/filesystems/00-INDEX | 2 Documentation/filesystems/unionfs/00-INDEX | 10 Documentation/filesystems/unionfs/concepts.txt | 199 ++ Documentation/filesystems/unionfs/issues.txt | 24 Documentation/filesystems/unionfs/rename.txt | 31 Documentation/filesystems/unionfs/usage.txt | 131 + MAINTAINERS | 9 fs/Kconfig | 53 fs/Makefile | 1 fs/ecryptfs/dentry.c | 2 fs/ecryptfs/inode.c | 6 fs/ecryptfs/main.c | 2 fs/namei.c | 1 fs/stack.c | 30 fs/unionfs/Makefile | 13 fs/unionfs/commonfops.c | 827 ++++++++++ fs/unionfs/copyup.c | 897 +++++++++++ fs/unionfs/debug.c | 532 ++++++ fs/unionfs/dentry.c | 509 ++++++ fs/unionfs/dirfops.c | 290 +++ fs/unionfs/dirhelper.c | 272 +++ fs/unionfs/fanout.h | 355 ++++ fs/unionfs/file.c | 227 ++ fs/unionfs/inode.c | 1154 +++++++++++++++ fs/unionfs/lookup.c | 652 ++++++++ fs/unionfs/main.c | 783 ++++++++++ fs/unionfs/mmap.c | 338 ++++ fs/unionfs/rdstate.c | 285 +++ fs/unionfs/rename.c | 533 ++++++ fs/unionfs/sioq.c | 119 + fs/unionfs/sioq.h | 92 + fs/unionfs/subr.c | 242 +++ fs/unionfs/super.c | 1010 +++++++++++++ fs/unionfs/union.h | 592 +++++++ fs/unionfs/unlink.c | 236 +++ fs/unionfs/xattr.c | 153 + include/linux/fs_stack.h | 21 include/linux/magic.h | 2 include/linux/namei.h | 13 include/linux/union_fs.h | 24 40 files changed, 10637 insertions(+), 35 deletions(-) diff -puN Documentation/filesystems/00-INDEX~git-unionfs Documentation/filesystems/00-INDEX --- a/Documentation/filesystems/00-INDEX~git-unionfs +++ a/Documentation/filesystems/00-INDEX @@ -96,6 +96,8 @@ udf.txt - info and mount options for the UDF filesystem. ufs.txt - info on the ufs filesystem. +unionfs/ + - info on the unionfs filesystem vfat.txt - info on using the VFAT filesystem used in Windows NT and Windows 95 vfs.txt diff -puN /dev/null Documentation/filesystems/unionfs/00-INDEX --- /dev/null +++ a/Documentation/filesystems/unionfs/00-INDEX @@ -0,0 +1,10 @@ +00-INDEX + - this file. +concepts.txt + - A brief introduction of concepts. +issues.txt + - A summary of known issues with unionfs. +rename.txt + - Information regarding rename operations. +usage.txt + - Usage information and examples. diff -puN /dev/null Documentation/filesystems/unionfs/concepts.txt --- /dev/null +++ a/Documentation/filesystems/unionfs/concepts.txt @@ -0,0 +1,199 @@ +Unionfs 2.1 CONCEPTS: +===================== + +This file describes the concepts needed by a namespace unification file +system. + + +Branch Priority: +================ + +Each branch is assigned a unique priority - starting from 0 (highest +priority). No two branches can have the same priority. + + +Branch Mode: +============ + +Each branch is assigned a mode - read-write or read-only. This allows +directories on media mounted read-write to be used in a read-only manner. + + +Whiteouts: +========== + +A whiteout removes a file name from the namespace. Whiteouts are needed when +one attempts to remove a file on a read-only branch. + +Suppose we have a two-branch union, where branch 0 is read-write and branch +1 is read-only. And a file 'foo' on branch 1: + +./b0/ +./b1/ +./b1/foo + +The unified view would simply be: + +./union/ +./union/foo + +Since 'foo' is stored on a read-only branch, it cannot be removed. A +whiteout is used to remove the name 'foo' from the unified namespace. Again, +since branch 1 is read-only, the whiteout cannot be created there. So, we +try on a higher priority (lower numerically) branch and create the whiteout +there. + +./b0/ +./b0/.wh.foo +./b1/ +./b1/foo + +Later, when Unionfs traverses branches (due to lookup or readdir), it +eliminate 'foo' from the namespace (as well as the whiteout itself.) + + +Duplicate Elimination: +====================== + +It is possible for files on different branches to have the same name. +Unionfs then has to select which instance of the file to show to the user. +Given the fact that each branch has a priority associated with it, the +simplest solution is to take the instance from the highest priority +(numerically lowest value) and "hide" the others. + + +Copyup: +======= + +When a change is made to the contents of a file's data or meta-data, they +have to be stored somewhere. The best way is to create a copy of the +original file on a branch that is writable, and then redirect the write +though to this copy. The copy must be made on a higher priority branch so +that lookup and readdir return this newer "version" of the file rather than +the original (see duplicate elimination). + + +Cache Coherency: +================ + +Unionfs users often want to be able to modify files and directories directly +on the lower branches, and have those changes be visible at the Unionfs +level. This means that data (e.g., pages) and meta-data (dentries, inodes, +open files, etc.) have to be synchronized between the upper and lower +layers. In other words, the newest changes from a layer below have to be +propagated to the Unionfs layer above. If the two layers are not in sync, a +cache incoherency ensues, which could lead to application failures and even +oopses. The Linux kernel, however, has a rather limited set of mechanisms +to ensure this inter-layer cache coherency---so Unionfs has to do most of +the hard work on its own. + +Maintaining Invariants: + +The way Unionfs ensures cache coherency is as follows. At each entry point +to a Unionfs file system method, we call a utility function to validate the +primary objects of this method. Generally, we call unionfs_file_revalidate +on open files, and __unionfs_d_revalidate_chain on dentries (which also +validates inodes). These utility functions check to see whether the upper +Unionfs object is in sync with any of the lower objects that it represents. +The checks we perform include whether the Unionfs superblock has a newer +generation number, or if any of the lower objects mtime's or ctime's are +newer. (Note: generation numbers change when branch-management commands are +issued, so in a way, maintaining cache coherency is also very important for +branch-management.) If indeed we determine that any Unionfs object is no +longer in sync with its lower counterparts, then we rebuild that object +similarly to how we do so for branch-management. + +While rebuilding Unionfs's objects, we also purge any page mappings and +truncate inode pages (see fs/unionfs/dentry.c:purge_inode_data). This is to +ensure that Unionfs will re-get the newer data from the lower branches. We +perform this purging only if the Unionfs operation in question is a reading +operation; if Unionfs is performing a data writing operation (e.g., ->write, +->commit_write, etc.) then we do NOT flush the lower mappings/pages: this is +because (1) a self-deadlock could occur and (2) the upper Unionfs pages are +considered more authoritative anyway, as they are newer and will overwrite +any lower pages. + +Unionfs maintains the following important invariant regarding mtime's, +ctime's, and atime's: the upper inode object's times are the max() of all of +the lower ones. For non-directory objects, there's only one object below, +so the mapping is simple; for directory objects, there could me multiple +lower objects and we have to sync up with the newest one of all the lower +ones. This invariant is important to maintain, especially for directories +(besides, we need this to be POSIX compliant). A union could comprise +multiple writable branches, each of which could change. If we don't reflect +the newest possible mtime/ctime, some applications could fail. For example, +NFSv2/v3 exports check for newer directory mtimes on the server to determine +if the client-side attribute cache should be purged. + +To maintain these important invariants, of course, Unionfs carefully +synchronizes upper and lower times in various places. For example, if we +copy-up a file to a top-level branch, the parent directory where the file +was copied up to will now have a new mtime: so after a successful copy-up, +we sync up with the new top-level branch's parent directory mtime. + +Implementation: + +This cache-coherency implementation is efficient because it defers any +synchronizing between the upper and lower layers until absolutely needed. +Consider the example a common situation where users perform a lot of lower +changes, such as untarring a whole package. While these take place, +typically the user doesn't access the files via Unionfs; only after the +lower changes are done, does the user try to access the lower files. With +our cache-coherency implementation, the entirety of the changes to the lower +branches will not result in a single CPU cycle spent at the Unionfs level +until the user invokes a system call that goes through Unionfs. + +We have considered two alternate cache-coherency designs. (1) Using the +dentry/inode notify functionality to register interest in finding out about +any lower changes. This is a somewhat limited and also a heavy-handed +approach which could result in many notifications to the Unionfs layer upon +each small change at the lower layer (imagine a file being modified multiple +times in rapid succession). (2) Rewriting the VFS to support explicit +callbacks from lower objects to upper objects. We began exploring such an +implementation, but found it to be very complicated--it would have resulted +in massive VFS/MM changes which are unlikely to be accepted by the LKML +community. We therefore believe that our current cache-coherency design and +implementation represent the best approach at this time. + +Limitations: + +Our implementation works in that as long as a user process will have caused +Unionfs to be called, directly or indirectly, even to just do +->d_revalidate; then we will have purged the current Unionfs data and the +process will see the new data. For example, a process that continually +re-reads the same file's data will see the NEW data as soon as the lower +file had changed, upon the next read(2) syscall (even if the file is still +open!) However, this doesn't work when the process re-reads the open file's +data via mmap(2) (unless the user unmaps/closes the file and remaps/reopens +it). Once we respond to ->readpage(s), then the kernel maps the page into +the process's address space and there doesn't appear to be a way to force +the kernel to invalidate those pages/mappings, and force the process to +re-issue ->readpage. If there's a way to invalidate active mappings and +force a ->readpage, let us know please (invalidate_inode_pages2 doesn't do +the trick). + +Our current Unionfs code has to perform many file-revalidation calls. It +would be really nice if the VFS would export an optional file system hook +->file_revalidate (similarly to dentry->d_revalidate) that will be called +before each VFS op that has a "struct file" in it. + +Certain file systems have micro-second granularity (or better) for inode +times, and asynchronous actions could cause those times to change with some +small delay. In such cases, Unionfs may see a changed inode time that only +differs by a tiny fraction of a second: such a change may be a false +positive indication that the lower object has changed, whereas if unionfs +waits a little longer, that false indication will not be seen. (These false +positives are harmless, because they would at most cause unionfs to +re-validate an object that may need no revalidation, and print a debugging +message that clutters the console/logs.) Therefore, to minimize the chances +of these situations, we delay the detection of changed times by a small +factor of a few seconds, called UNIONFS_MIN_CC_TIME (which defaults to 3 +seconds, as does NFS). This means that we will detect the change, only a +couple of seconds later, if indeed the time change persists in the lower +file object. This delayed detection has an added performance benefit: we +reduce the number of times that unionfs has to revalidate objects, in case +there's a lot of concurrent activity on both the upper and lower objects, +for the same file(s). Lastly, this delayed time attribute detection is +similar to how NFS clients operate (e.g., acregmin). + +For more information, see . diff -puN /dev/null Documentation/filesystems/unionfs/issues.txt --- /dev/null +++ a/Documentation/filesystems/unionfs/issues.txt @@ -0,0 +1,24 @@ +KNOWN Unionfs 2.1 ISSUES: +========================= + +1. Unionfs should not use lookup_one_len() on the underlying f/s as it + confuses NFSv4. Currently, unionfs_lookup() passes lookup intents to the + lower file-system, this eliminates part of the problem. The remaining + calls to lookup_one_len may need to be changed to pass an intent. We are + currently introducing VFS changes to fs/namei.c's do_path_lookup() to + allow proper file lookup and opening in stackable file systems. + +2. Lockdep (a debugging feature) isn't aware of stacking, and so it + incorrectly complains about locking problems. The problem boils down to + this: Lockdep considers all objects of a certain type to be in the same + class, for example, all inodes. Lockdep doesn't like to see a lock held + on two inodes within the same task, and warns that it could lead to a + deadlock. However, stackable file systems do precisely that: they lock + an upper object, and then a lower object, in a strict order to avoid + locking problems; in addition, Unionfs, as a fan-out file system, may + have to lock several lower inodes. We are currently looking into Lockdep + to see how to make it aware of stackable file systems. In the meantime, + if you get any warnings from Lockdep, you can safely ignore them (or feel + free to report them to the Unionfs maintainers, just to be sure). + +For more information, see . diff -puN /dev/null Documentation/filesystems/unionfs/rename.txt --- /dev/null +++ a/Documentation/filesystems/unionfs/rename.txt @@ -0,0 +1,31 @@ +Rename is a complex beast. The following table shows which rename(2) operations +should succeed and which should fail. + +o: success +E: error (either unionfs or vfs) +X: EXDEV + +none = file does not exist +file = file is a file +dir = file is a empty directory +child= file is a non-empty directory +wh = file is a directory containing only whiteouts; this makes it logically + empty + + none file dir child wh +file o o E E E +dir o E o E o +child X E X E X +wh o E o E o + + +Renaming directories: +===================== + +Whenever a empty (either physically or logically) directory is being renamed, +the following sequence of events should take place: + +1) Remove whiteouts from both source and destination directory +2) Rename source to destination +3) Make destination opaque to prevent anything under it from showing up + diff -puN /dev/null Documentation/filesystems/unionfs/usage.txt --- /dev/null +++ a/Documentation/filesystems/unionfs/usage.txt @@ -0,0 +1,131 @@ +Unionfs is a stackable unification file system, which can appear to merge +the contents of several directories (branches), while keeping their physical +content separate. Unionfs is useful for unified source tree management, +merged contents of split CD-ROM, merged separate software package +directories, data grids, and more. Unionfs allows any mix of read-only and +read-write branches, as well as insertion and deletion of branches anywhere +in the fan-out. To maintain Unix semantics, Unionfs handles elimination of +duplicates, partial-error conditions, and more. + +GENERAL SYNTAX +============== + +# mount -t unionfs -o , none MOUNTPOINT + +OPTIONS can be any legal combination one of: + +- ro # mount file system read-only +- rw # mount file system read-write +- remount # remount the file system (see Branch Management below) +- incgen # increment generation no. (see Cache Consistency below) + +BRANCH-OPTIONS can be either (1) a list of branches given to the "dirs=" +option, or (2) a list of individual branch manipulation commands, described +in the "Branch Management" section below. + +The syntax for the "dirs=" mount option is: + + dirs=branch[=ro|=rw][:...] + +The "dirs=" option takes a colon-delimited list of directories to compose +the union, with an optional branch mode for each of those directories. +Directories that come earlier (specified first, on the left) in the list +have a higher precedence than those which come later. Additionally, +read-only or read-write permissions of the branch can be specified by +appending =ro or =rw (default) to each directory. + +Syntax: + + dirs=/branch1[=ro|=rw]:/branch2[=ro|=rw]:...:/branchN[=ro|=rw] + +Example: + + dirs=/writable_branch=rw:/read-only_branch=ro + + +BRANCH MANAGEMENT +================= + +Once you mount your union for the first time, using the "dirs=" option, you +can then change the union's overall mode or reconfigure the branches, using +the remount option, as follows. + +To downgrade a union from read-write to read-only: + +# mount -t unionfs -o remount,ro none MOUNTPOINT + +To upgrade a union from read-only to read-write: + +# mount -t unionfs -o remount,rw none MOUNTPOINT + +To delete a branch /foo, regardless where it is in the current union: + +# mount -t unionfs -o remount,del=/foo none MOUNTPOINT + +To insert (add) a branch /foo before /bar: + +# mount -t unionfs -o remount,add=/bar:/foo none MOUNTPOINT + +To insert (add) a branch /foo (with the "rw" mode flag) before /bar: + +# mount -t unionfs -o remount,add=/bar:/foo=rw none MOUNTPOINT + +To insert (add) a branch /foo (in "rw" mode) at the very beginning (i.e., a +new highest-priority branch), you can use the above syntax, or use a short +hand version as follows: + +# mount -t unionfs -o remount,add=/foo none MOUNTPOINT + +To append a branch to the very end (new lowest-priority branch): + +# mount -t unionfs -o remount,add=:/foo none MOUNTPOINT + +To append a branch to the very end (new lowest-priority branch), in +read-only mode: + +# mount -t unionfs -o remount,add=:/foo=ro none MOUNTPOINT + +Finally, to change the mode of one existing branch, say /foo, from read-only +to read-write, and change /bar from read-write to read-only: + +# mount -t unionfs -o remount,mode=/foo=rw,mode=/bar=ro none MOUNTPOINT + +Note: in Unionfs 2.x, you cannot set the leftmost branch to readonly because +then Unionfs won't have any writable place for copyups to take place. +Moreover, the VFS can get confused when it tries to modify something in a +file system mounted read-write, but isn't permitted to write to it. +Instead, you should set the whole union as readonly, as described above. +If, however, you must set the leftmost branch as readonly, perhaps so you +can get a snapshot of it at a point in time, then you should insert a new +writable top-level branch, and mark the one you want as readonly. This can +be accomplished as follows, assuming that /foo is your current leftmost +branch: + +# mount -t tmpfs -o size=NNN /new +# mount -t unionfs -o remount,add=/new,mode=/foo=ro none MOUNTPOINT + +# mount -t unionfs -o remount,del=/new,mode=/foo=rw none MOUNTPOINT + +# umount /new + +CACHE CONSISTENCY +================= + +If you modify any file on any of the lower branches directly, while there is +a Unionfs 2.1 mounted above any of those branches, you should tell Unionfs +to purge its caches and re-get the objects. To do that, you have to +increment the generation number of the superblock using the following +command: + +# mount -t unionfs -o remount,incgen none MOUNTPOINT + +Note that the older way of incrementing the generation number using an +ioctl, is no longer supported in Unionfs 2.0 and newer. Ioctls in general +are not encouraged. Plus, an ioctl is per-file concept, whereas the +generation number is a per-file-system concept. Worse, such an ioctl +requires an open file, which then has to be invalidated by the very nature +of the generation number increase (read: the old generation increase ioctl +was pretty racy). + + +For more information, see . diff -puN MAINTAINERS~git-unionfs MAINTAINERS --- a/MAINTAINERS~git-unionfs +++ a/MAINTAINERS @@ -3830,6 +3830,15 @@ L: linux-kernel@vger.kernel.org W: http://www.kernel.dk S: Maintained +UNIONFS +P: Erez Zadok +M: ezk@cs.sunysb.edu +P: Josef "Jeff" Sipek +M: jsipek@cs.sunysb.edu +L: unionfs@filesystems.org +W: http://unionfs.filesystems.org +S: Maintained + USB ACM DRIVER P: Oliver Neukum M: oliver@neukum.name diff -puN fs/Kconfig~git-unionfs fs/Kconfig --- a/fs/Kconfig~git-unionfs +++ a/fs/Kconfig @@ -1035,6 +1035,47 @@ config CONFIGFS_FS endmenu +menu "Layered filesystems" + +config ECRYPT_FS + tristate "eCrypt filesystem layer support (EXPERIMENTAL)" + depends on EXPERIMENTAL && KEYS && CRYPTO && NET + help + Encrypted filesystem that operates on the VFS layer. See + to learn more about + eCryptfs. Userspace components are required and can be + obtained from . + + To compile this file system support as a module, choose M here: the + module will be called ecryptfs. + +config UNION_FS + tristate "Union file system (EXPERIMENTAL)" + depends on EXPERIMENTAL + help + Unionfs is a stackable unification file system, which appears to + merge the contents of several directories (branches), while keeping + their physical content separate. + + See for details + +config UNION_FS_XATTR + bool "Unionfs extended attributes" + depends on UNION_FS + help + Extended attributes are name:value pairs associated with inodes by + the kernel or by users (see the attr(5) manual page). + + If unsure, say N. + +config UNION_FS_DEBUG + bool "Debug Unionfs" + depends on UNION_FS + help + If you say Y here, you can turn on debugging output from Unionfs. + +endmenu + menu "Miscellaneous filesystems" config ADFS_FS @@ -1087,18 +1128,6 @@ config AFFS_FS To compile this file system support as a module, choose M here: the module will be called affs. If unsure, say N. -config ECRYPT_FS - tristate "eCrypt filesystem layer support (EXPERIMENTAL)" - depends on EXPERIMENTAL && KEYS && CRYPTO && NET - help - Encrypted filesystem that operates on the VFS layer. See - to learn more about - eCryptfs. Userspace components are required and can be - obtained from . - - To compile this file system support as a module, choose M here: the - module will be called ecryptfs. - config HFS_FS tristate "Apple Macintosh file system support (EXPERIMENTAL)" depends on BLOCK && EXPERIMENTAL diff -puN fs/Makefile~git-unionfs fs/Makefile --- a/fs/Makefile~git-unionfs +++ a/fs/Makefile @@ -118,3 +118,4 @@ obj-$(CONFIG_HPPFS) += hppfs/ obj-$(CONFIG_DEBUG_FS) += debugfs/ obj-$(CONFIG_OCFS2_FS) += ocfs2/ obj-$(CONFIG_GFS2_FS) += gfs2/ +obj-$(CONFIG_UNION_FS) += unionfs/ diff -puN fs/ecryptfs/dentry.c~git-unionfs fs/ecryptfs/dentry.c --- a/fs/ecryptfs/dentry.c~git-unionfs +++ a/fs/ecryptfs/dentry.c @@ -62,7 +62,7 @@ static int ecryptfs_d_revalidate(struct struct inode *lower_inode = ecryptfs_inode_to_lower(dentry->d_inode); - fsstack_copy_attr_all(dentry->d_inode, lower_inode, NULL); + fsstack_copy_attr_all(dentry->d_inode, lower_inode); } out: return rc; diff -puN fs/ecryptfs/inode.c~git-unionfs fs/ecryptfs/inode.c --- a/fs/ecryptfs/inode.c~git-unionfs +++ a/fs/ecryptfs/inode.c @@ -588,9 +588,9 @@ ecryptfs_rename(struct inode *old_dir, s lower_new_dir_dentry->d_inode, lower_new_dentry); if (rc) goto out_lock; - fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL); + fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode); if (new_dir != old_dir) - fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL); + fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode); out_lock: unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry); dput(lower_new_dentry->d_parent); @@ -924,7 +924,7 @@ static int ecryptfs_setattr(struct dentr rc = notify_change(lower_dentry, ia); out: - fsstack_copy_attr_all(inode, lower_inode, NULL); + fsstack_copy_attr_all(inode, lower_inode); return rc; } diff -puN fs/ecryptfs/main.c~git-unionfs fs/ecryptfs/main.c --- a/fs/ecryptfs/main.c~git-unionfs +++ a/fs/ecryptfs/main.c @@ -211,7 +211,7 @@ int ecryptfs_interpose(struct dentry *lo d_add(dentry, inode); else d_instantiate(dentry, inode); - fsstack_copy_attr_all(inode, lower_inode, NULL); + fsstack_copy_attr_all(inode, lower_inode); /* This size will be overwritten for real files w/ headers and * other metadata */ fsstack_copy_inode_size(inode, lower_inode); diff -puN fs/namei.c~git-unionfs fs/namei.c --- a/fs/namei.c~git-unionfs +++ a/fs/namei.c @@ -389,6 +389,7 @@ void release_open_intent(struct nameidat else fput(nd->intent.open.file); } +EXPORT_SYMBOL(release_open_intent); static inline struct dentry * do_revalidate(struct dentry *dentry, struct nameidata *nd) diff -puN fs/stack.c~git-unionfs fs/stack.c --- a/fs/stack.c~git-unionfs +++ a/fs/stack.c @@ -1,8 +1,20 @@ +/* + * Copyright (c) 2006-2007 Erez Zadok + * Copyright (c) 2006-2007 Josef 'Jeff' Sipek + * Copyright (c) 2006-2007 Stony Brook University + * Copyright (c) 2006-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + #include #include #include -/* does _NOT_ require i_mutex to be held. +/* + * does _NOT_ require i_mutex to be held. * * This function cannot be inlined since i_size_{read,write} is rather * heavy-weight on 32-bit systems @@ -14,11 +26,11 @@ void fsstack_copy_inode_size(struct inod } EXPORT_SYMBOL_GPL(fsstack_copy_inode_size); -/* copy all attributes; get_nlinks is optional way to override the i_nlink +/* + * copy all attributes; get_nlinks is optional way to override the i_nlink * copying */ -void fsstack_copy_attr_all(struct inode *dest, const struct inode *src, - int (*get_nlinks)(struct inode *)) +void fsstack_copy_attr_all(struct inode *dest, const struct inode *src) { dest->i_mode = src->i_mode; dest->i_uid = src->i_uid; @@ -29,14 +41,6 @@ void fsstack_copy_attr_all(struct inode dest->i_ctime = src->i_ctime; dest->i_blkbits = src->i_blkbits; dest->i_flags = src->i_flags; - - /* - * Update the nlinks AFTER updating the above fields, because the - * get_links callback may depend on them. - */ - if (!get_nlinks) - dest->i_nlink = src->i_nlink; - else - dest->i_nlink = (*get_nlinks)(dest); + dest->i_nlink = src->i_nlink; } EXPORT_SYMBOL_GPL(fsstack_copy_attr_all); diff -puN /dev/null fs/unionfs/Makefile --- /dev/null +++ a/fs/unionfs/Makefile @@ -0,0 +1,13 @@ +obj-$(CONFIG_UNION_FS) += unionfs.o + +unionfs-y := subr.o dentry.o file.o inode.o main.o super.o \ + rdstate.o copyup.o dirhelper.o rename.o unlink.o \ + lookup.o commonfops.o dirfops.o sioq.o mmap.o + +unionfs-$(CONFIG_UNION_FS_XATTR) += xattr.o + +unionfs-$(CONFIG_UNION_FS_DEBUG) += debug.o + +ifeq ($(CONFIG_UNION_FS_DEBUG),y) +EXTRA_CFLAGS += -DDEBUG +endif diff -puN /dev/null fs/unionfs/commonfops.c --- /dev/null +++ a/fs/unionfs/commonfops.c @@ -0,0 +1,827 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * 1) Copyup the file + * 2) Rename the file to '.unionfs' - obviously + * stolen from NFS's silly rename + */ +static int copyup_deleted_file(struct file *file, struct dentry *dentry, + int bstart, int bindex) +{ + static unsigned int counter; + const int i_inosize = sizeof(dentry->d_inode->i_ino) * 2; + const int countersize = sizeof(counter) * 2; + const int nlen = sizeof(".unionfs") + i_inosize + countersize - 1; + char name[nlen + 1]; + int err; + struct dentry *tmp_dentry = NULL; + struct dentry *lower_dentry; + struct dentry *lower_dir_dentry = NULL; + + lower_dentry = unionfs_lower_dentry_idx(dentry, bstart); + + sprintf(name, ".unionfs%*.*lx", + i_inosize, i_inosize, lower_dentry->d_inode->i_ino); + + /* + * Loop, looking for an unused temp name to copyup to. + * + * It's somewhat silly that we look for a free temp tmp name in the + * source branch (bstart) instead of the dest branch (bindex), where + * the final name will be created. We _will_ catch it if somehow + * the name exists in the dest branch, but it'd be nice to catch it + * sooner than later. + */ +retry: + tmp_dentry = NULL; + do { + char *suffix = name + nlen - countersize; + + dput(tmp_dentry); + counter++; + sprintf(suffix, "%*.*x", countersize, countersize, counter); + + pr_debug("unionfs: trying to rename %s to %s\n", + dentry->d_name.name, name); + + tmp_dentry = lookup_one_len(name, lower_dentry->d_parent, + nlen); + if (IS_ERR(tmp_dentry)) { + err = PTR_ERR(tmp_dentry); + goto out; + } + } while (tmp_dentry->d_inode != NULL); /* need negative dentry */ + dput(tmp_dentry); + + err = copyup_named_file(dentry->d_parent->d_inode, file, name, bstart, + bindex, + i_size_read(file->f_path.dentry->d_inode)); + if (err) { + if (unlikely(err == -EEXIST)) + goto retry; + goto out; + } + + /* bring it to the same state as an unlinked file */ + lower_dentry = unionfs_lower_dentry_idx(dentry, dbstart(dentry)); + if (!unionfs_lower_inode_idx(dentry->d_inode, bindex)) { + atomic_inc(&lower_dentry->d_inode->i_count); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, + lower_dentry->d_inode); + } + lower_dir_dentry = lock_parent(lower_dentry); + err = vfs_unlink(lower_dir_dentry->d_inode, lower_dentry); + unlock_dir(lower_dir_dentry); + +out: + if (!err) + unionfs_check_dentry(dentry); + return err; +} + +/* + * put all references held by upper struct file and free lower file pointer + * array + */ +static void cleanup_file(struct file *file) +{ + int bindex, bstart, bend; + struct file **lower_files; + struct file *lower_file; + struct super_block *sb = file->f_path.dentry->d_sb; + + lower_files = UNIONFS_F(file)->lower_files; + bstart = fbstart(file); + bend = fbend(file); + + for (bindex = bstart; bindex <= bend; bindex++) { + int i; /* holds (possibly) updated branch index */ + int old_bid; + + lower_file = unionfs_lower_file_idx(file, bindex); + if (!lower_file) + continue; + + /* + * Find new index of matching branch with an open + * file, since branches could have been added or + * deleted causing the one with open files to shift. + */ + old_bid = UNIONFS_F(file)->saved_branch_ids[bindex]; + i = branch_id_to_idx(sb, old_bid); + if (unlikely(i < 0)) { + printk(KERN_ERR "unionfs: no superblock for " + "file %p\n", file); + continue; + } + + /* decrement count of open files */ + branchput(sb, i); + /* + * fput will perform an mntput for us on the correct branch. + * Although we're using the file's old branch configuration, + * bindex, which is the old index, correctly points to the + * right branch in the file's branch list. In other words, + * we're going to mntput the correct branch even if branches + * have been added/removed. + */ + fput(lower_file); + UNIONFS_F(file)->lower_files[bindex] = NULL; + UNIONFS_F(file)->saved_branch_ids[bindex] = -1; + } + + UNIONFS_F(file)->lower_files = NULL; + kfree(lower_files); + kfree(UNIONFS_F(file)->saved_branch_ids); + /* set to NULL because caller needs to know if to kfree on error */ + UNIONFS_F(file)->saved_branch_ids = NULL; +} + +/* open all lower files for a given file */ +static int open_all_files(struct file *file) +{ + int bindex, bstart, bend, err = 0; + struct file *lower_file; + struct dentry *lower_dentry; + struct dentry *dentry = file->f_path.dentry; + struct super_block *sb = dentry->d_sb; + + bstart = dbstart(dentry); + bend = dbend(dentry); + + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) + continue; + + dget(lower_dentry); + unionfs_mntget(dentry, bindex); + branchget(sb, bindex); + + lower_file = + dentry_open(lower_dentry, + unionfs_lower_mnt_idx(dentry, bindex), + file->f_flags); + if (IS_ERR(lower_file)) { + err = PTR_ERR(lower_file); + goto out; + } else { + unionfs_set_lower_file_idx(file, bindex, lower_file); + } + } +out: + return err; +} + +/* open the highest priority file for a given upper file */ +static int open_highest_file(struct file *file, bool willwrite) +{ + int bindex, bstart, bend, err = 0; + struct file *lower_file; + struct dentry *lower_dentry; + struct dentry *dentry = file->f_path.dentry; + struct inode *parent_inode = dentry->d_parent->d_inode; + struct super_block *sb = dentry->d_sb; + + bstart = dbstart(dentry); + bend = dbend(dentry); + + lower_dentry = unionfs_lower_dentry(dentry); + if (willwrite && IS_WRITE_FLAG(file->f_flags) && is_robranch(dentry)) { + for (bindex = bstart - 1; bindex >= 0; bindex--) { + err = copyup_file(parent_inode, file, bstart, bindex, + i_size_read(dentry->d_inode)); + if (!err) + break; + } + atomic_set(&UNIONFS_F(file)->generation, + atomic_read(&UNIONFS_I(dentry->d_inode)-> + generation)); + goto out; + } + + dget(lower_dentry); + unionfs_mntget(dentry, bstart); + lower_file = dentry_open(lower_dentry, + unionfs_lower_mnt_idx(dentry, bstart), + file->f_flags); + if (IS_ERR(lower_file)) { + err = PTR_ERR(lower_file); + goto out; + } + branchget(sb, bstart); + unionfs_set_lower_file(file, lower_file); + /* Fix up the position. */ + lower_file->f_pos = file->f_pos; + + memcpy(&lower_file->f_ra, &file->f_ra, sizeof(struct file_ra_state)); +out: + return err; +} + +/* perform a delayed copyup of a read-write file on a read-only branch */ +static int do_delayed_copyup(struct file *file) +{ + int bindex, bstart, bend, err = 0; + struct dentry *dentry = file->f_path.dentry; + struct inode *parent_inode = dentry->d_parent->d_inode; + + bstart = fbstart(file); + bend = fbend(file); + + BUG_ON(!S_ISREG(dentry->d_inode->i_mode)); + + unionfs_check_file(file); + unionfs_check_dentry(dentry); + for (bindex = bstart - 1; bindex >= 0; bindex--) { + if (!d_deleted(dentry)) + err = copyup_file(parent_inode, file, bstart, + bindex, + i_size_read(dentry->d_inode)); + else + err = copyup_deleted_file(file, dentry, bstart, + bindex); + + if (!err) + break; + } + if (err || (bstart <= fbstart(file))) + goto out; + bend = fbend(file); + for (bindex = bstart; bindex <= bend; bindex++) { + if (unionfs_lower_file_idx(file, bindex)) { + branchput(dentry->d_sb, bindex); + fput(unionfs_lower_file_idx(file, bindex)); + unionfs_set_lower_file_idx(file, bindex, NULL); + } + if (unionfs_lower_mnt_idx(dentry, bindex)) { + unionfs_mntput(dentry, bindex); + unionfs_set_lower_mnt_idx(dentry, bindex, NULL); + } + if (unionfs_lower_dentry_idx(dentry, bindex)) { + BUG_ON(!dentry->d_inode); + iput(unionfs_lower_inode_idx(dentry->d_inode, bindex)); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, + NULL); + dput(unionfs_lower_dentry_idx(dentry, bindex)); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + } + } + /* for reg file, we only open it "once" */ + fbend(file) = fbstart(file); + set_dbend(dentry, dbstart(dentry)); + ibend(dentry->d_inode) = ibstart(dentry->d_inode); + +out: + unionfs_check_file(file); + unionfs_check_dentry(dentry); + return err; +} + +/* + * Revalidate the struct file + * @file: file to revalidate + * @willwrite: true if caller may cause changes to the file; false otherwise. + */ +int unionfs_file_revalidate(struct file *file, bool willwrite) +{ + struct super_block *sb; + struct dentry *dentry; + int sbgen, fgen, dgen; + int bstart, bend; + int size; + int err = 0; + + dentry = file->f_path.dentry; + unionfs_lock_dentry(dentry); + sb = dentry->d_sb; + + /* + * First revalidate the dentry inside struct file, + * but not unhashed dentries. + */ + if (unlikely(!d_deleted(dentry) && + !__unionfs_d_revalidate_chain(dentry, NULL, willwrite))) { + err = -ESTALE; + goto out_nofree; + } + + sbgen = atomic_read(&UNIONFS_SB(sb)->generation); + dgen = atomic_read(&UNIONFS_D(dentry)->generation); + fgen = atomic_read(&UNIONFS_F(file)->generation); + + BUG_ON(sbgen > dgen); + + /* + * There are two cases we are interested in. The first is if the + * generation is lower than the super-block. The second is if + * someone has copied up this file from underneath us, we also need + * to refresh things. + */ + if (unlikely(!d_deleted(dentry) && + (sbgen > fgen || dbstart(dentry) != fbstart(file)))) { + /* save orig branch ID */ + int orig_brid = + UNIONFS_F(file)->saved_branch_ids[fbstart(file)]; + + /* First we throw out the existing files. */ + cleanup_file(file); + + /* Now we reopen the file(s) as in unionfs_open. */ + bstart = fbstart(file) = dbstart(dentry); + bend = fbend(file) = dbend(dentry); + + size = sizeof(struct file *) * sbmax(sb); + UNIONFS_F(file)->lower_files = kzalloc(size, GFP_KERNEL); + if (unlikely(!UNIONFS_F(file)->lower_files)) { + err = -ENOMEM; + goto out; + } + size = sizeof(int) * sbmax(sb); + UNIONFS_F(file)->saved_branch_ids = kzalloc(size, GFP_KERNEL); + if (unlikely(!UNIONFS_F(file)->saved_branch_ids)) { + err = -ENOMEM; + goto out; + } + + if (S_ISDIR(dentry->d_inode->i_mode)) { + /* We need to open all the files. */ + err = open_all_files(file); + if (err) + goto out; + } else { + int new_brid; + /* We only open the highest priority branch. */ + err = open_highest_file(file, willwrite); + if (err) + goto out; + new_brid = UNIONFS_F(file)-> + saved_branch_ids[fbstart(file)]; + if (unlikely(new_brid != orig_brid && sbgen > fgen)) { + /* + * If we re-opened the file on a different + * branch than the original one, and this + * was due to a new branch inserted, then + * update the mnt counts of the old and new + * branches accordingly. + */ + unionfs_mntget(dentry, bstart); + unionfs_mntput(sb->s_root, + branch_id_to_idx(sb, orig_brid)); + } + } + atomic_set(&UNIONFS_F(file)->generation, + atomic_read( + &UNIONFS_I(dentry->d_inode)->generation)); + } + + /* Copyup on the first write to a file on a readonly branch. */ + if (willwrite && IS_WRITE_FLAG(file->f_flags) && + !IS_WRITE_FLAG(unionfs_lower_file(file)->f_flags) && + is_robranch(dentry)) { + pr_debug("unionfs: do delay copyup of \"%s\"\n", + dentry->d_name.name); + err = do_delayed_copyup(file); + } + +out: + if (err) { + kfree(UNIONFS_F(file)->lower_files); + kfree(UNIONFS_F(file)->saved_branch_ids); + } +out_nofree: + if (!err) + unionfs_check_file(file); + unionfs_unlock_dentry(dentry); + return err; +} + +/* unionfs_open helper function: open a directory */ +static int __open_dir(struct inode *inode, struct file *file) +{ + struct dentry *lower_dentry; + struct file *lower_file; + int bindex, bstart, bend; + struct vfsmount *mnt; + + bstart = fbstart(file) = dbstart(file->f_path.dentry); + bend = fbend(file) = dbend(file->f_path.dentry); + + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = + unionfs_lower_dentry_idx(file->f_path.dentry, bindex); + if (!lower_dentry) + continue; + + dget(lower_dentry); + unionfs_mntget(file->f_path.dentry, bindex); + mnt = unionfs_lower_mnt_idx(file->f_path.dentry, bindex); + lower_file = dentry_open(lower_dentry, mnt, file->f_flags); + if (IS_ERR(lower_file)) + return PTR_ERR(lower_file); + + unionfs_set_lower_file_idx(file, bindex, lower_file); + + /* + * The branchget goes after the open, because otherwise + * we would miss the reference on release. + */ + branchget(inode->i_sb, bindex); + } + + return 0; +} + +/* unionfs_open helper function: open a file */ +static int __open_file(struct inode *inode, struct file *file) +{ + struct dentry *lower_dentry; + struct file *lower_file; + int lower_flags; + int bindex, bstart, bend; + + lower_dentry = unionfs_lower_dentry(file->f_path.dentry); + lower_flags = file->f_flags; + + bstart = fbstart(file) = dbstart(file->f_path.dentry); + bend = fbend(file) = dbend(file->f_path.dentry); + + /* + * check for the permission for lower file. If the error is + * COPYUP_ERR, copyup the file. + */ + if (lower_dentry->d_inode && is_robranch(file->f_path.dentry)) { + /* + * if the open will change the file, copy it up otherwise + * defer it. + */ + if (lower_flags & O_TRUNC) { + int size = 0; + int err = -EROFS; + + /* copyup the file */ + for (bindex = bstart - 1; bindex >= 0; bindex--) { + err = copyup_file( + file->f_path.dentry->d_parent->d_inode, + file, bstart, bindex, size); + if (!err) + break; + } + return err; + } else { + lower_flags &= ~(OPEN_WRITE_FLAGS); + } + } + + dget(lower_dentry); + + /* + * dentry_open will decrement mnt refcnt if err. + * otherwise fput() will do an mntput() for us upon file close. + */ + unionfs_mntget(file->f_path.dentry, bstart); + lower_file = + dentry_open(lower_dentry, + unionfs_lower_mnt_idx(file->f_path.dentry, bstart), + lower_flags); + if (IS_ERR(lower_file)) + return PTR_ERR(lower_file); + + unionfs_set_lower_file(file, lower_file); + branchget(inode->i_sb, bstart); + + return 0; +} + +int unionfs_open(struct inode *inode, struct file *file) +{ + int err = 0; + struct file *lower_file = NULL; + struct dentry *dentry = NULL; + int bindex = 0, bstart = 0, bend = 0; + int size; + + unionfs_read_lock(inode->i_sb); + + file->private_data = + kzalloc(sizeof(struct unionfs_file_info), GFP_KERNEL); + if (unlikely(!UNIONFS_F(file))) { + err = -ENOMEM; + goto out_nofree; + } + fbstart(file) = -1; + fbend(file) = -1; + atomic_set(&UNIONFS_F(file)->generation, + atomic_read(&UNIONFS_I(inode)->generation)); + + size = sizeof(struct file *) * sbmax(inode->i_sb); + UNIONFS_F(file)->lower_files = kzalloc(size, GFP_KERNEL); + if (unlikely(!UNIONFS_F(file)->lower_files)) { + err = -ENOMEM; + goto out; + } + size = sizeof(int) * sbmax(inode->i_sb); + UNIONFS_F(file)->saved_branch_ids = kzalloc(size, GFP_KERNEL); + if (unlikely(!UNIONFS_F(file)->saved_branch_ids)) { + err = -ENOMEM; + goto out; + } + + dentry = file->f_path.dentry; + unionfs_lock_dentry(dentry); + + bstart = fbstart(file) = dbstart(dentry); + bend = fbend(file) = dbend(dentry); + + /* + * open all directories and make the unionfs file struct point to + * these lower file structs + */ + if (S_ISDIR(inode->i_mode)) + err = __open_dir(inode, file); /* open a dir */ + else + err = __open_file(inode, file); /* open a file */ + + /* freeing the allocated resources, and fput the opened files */ + if (err) { + for (bindex = bstart; bindex <= bend; bindex++) { + lower_file = unionfs_lower_file_idx(file, bindex); + if (!lower_file) + continue; + + branchput(file->f_path.dentry->d_sb, bindex); + /* fput calls dput for lower_dentry */ + fput(lower_file); + } + } + + /* XXX: should this unlock be moved to the function bottom? */ + unionfs_unlock_dentry(dentry); + +out: + if (err) { + kfree(UNIONFS_F(file)->lower_files); + kfree(UNIONFS_F(file)->saved_branch_ids); + kfree(UNIONFS_F(file)); + } +out_nofree: + unionfs_check_inode(inode); + if (!err) { + unionfs_check_file(file); + unionfs_check_dentry(file->f_path.dentry->d_parent); + } + unionfs_read_unlock(inode->i_sb); + return err; +} + +/* + * release all lower object references & free the file info structure + * + * No need to grab sb info's rwsem. + */ +int unionfs_file_release(struct inode *inode, struct file *file) +{ + struct file *lower_file = NULL; + struct unionfs_file_info *fileinfo; + struct unionfs_inode_info *inodeinfo; + struct super_block *sb = inode->i_sb; + struct dentry *dentry = file->f_path.dentry; + int bindex, bstart, bend; + int fgen, err = 0; + + unionfs_read_lock(sb); + /* + * Yes, we have to revalidate this file even if it's being released. + * This is important for open-but-unlinked files, as well as mmap + * support. + */ + err = unionfs_file_revalidate(file, true); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + fileinfo = UNIONFS_F(file); + BUG_ON(file->f_path.dentry->d_inode != inode); + inodeinfo = UNIONFS_I(inode); + + /* fput all the lower files */ + fgen = atomic_read(&fileinfo->generation); + bstart = fbstart(file); + bend = fbend(file); + + unionfs_lock_dentry(dentry); + for (bindex = bstart; bindex <= bend; bindex++) { + lower_file = unionfs_lower_file_idx(file, bindex); + + if (lower_file) { + fput(lower_file); + branchput(sb, bindex); + } + + /* if there are no more refs to the dentry, dput it */ + if (d_deleted(dentry)) { + dput(unionfs_lower_dentry_idx(dentry, bindex)); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + } + } + unionfs_unlock_dentry(dentry); + + kfree(fileinfo->lower_files); + kfree(fileinfo->saved_branch_ids); + + if (fileinfo->rdstate) { + fileinfo->rdstate->access = jiffies; + spin_lock(&inodeinfo->rdlock); + inodeinfo->rdcount++; + list_add_tail(&fileinfo->rdstate->cache, + &inodeinfo->readdircache); + mark_inode_dirty(inode); + spin_unlock(&inodeinfo->rdlock); + fileinfo->rdstate = NULL; + } + kfree(fileinfo); + +out: + unionfs_read_unlock(sb); + return err; +} + +/* pass the ioctl to the lower fs */ +static long do_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct file *lower_file; + int err; + + lower_file = unionfs_lower_file(file); + + err = -ENOTTY; + if (!lower_file || !lower_file->f_op) + goto out; + if (lower_file->f_op->unlocked_ioctl) { + err = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); + } else if (lower_file->f_op->ioctl) { + lock_kernel(); + err = lower_file->f_op->ioctl( + lower_file->f_path.dentry->d_inode, + lower_file, cmd, arg); + unlock_kernel(); + } + +out: + return err; +} + +/* + * return to user-space the branch indices containing the file in question + * + * We use fd_set and therefore we are limited to the number of the branches + * to FD_SETSIZE, which is currently 1024 - plenty for most people + */ +static int unionfs_ioctl_queryfile(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int err = 0; + fd_set branchlist; + int bstart = 0, bend = 0, bindex = 0; + int orig_bstart, orig_bend; + struct dentry *dentry, *lower_dentry; + struct vfsmount *mnt; + + dentry = file->f_path.dentry; + unionfs_lock_dentry(dentry); + orig_bstart = dbstart(dentry); + orig_bend = dbend(dentry); + err = unionfs_partial_lookup(dentry); + if (err) + goto out; + bstart = dbstart(dentry); + bend = dbend(dentry); + + FD_ZERO(&branchlist); + + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) + continue; + if (likely(lower_dentry->d_inode)) + FD_SET(bindex, &branchlist); + /* purge any lower objects after partial_lookup */ + if (bindex < orig_bstart || bindex > orig_bend) { + dput(lower_dentry); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + iput(unionfs_lower_inode_idx(dentry->d_inode, bindex)); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, + NULL); + mnt = unionfs_lower_mnt_idx(dentry, bindex); + if (!mnt) + continue; + unionfs_mntput(dentry, bindex); + unionfs_set_lower_mnt_idx(dentry, bindex, NULL); + } + } + /* restore original dentry's offsets */ + set_dbstart(dentry, orig_bstart); + set_dbend(dentry, orig_bend); + ibstart(dentry->d_inode) = orig_bstart; + ibend(dentry->d_inode) = orig_bend; + + err = copy_to_user((void __user *)arg, &branchlist, sizeof(fd_set)); + if (unlikely(err)) + err = -EFAULT; + +out: + unionfs_unlock_dentry(dentry); + return err < 0 ? err : bend; +} + +long unionfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + long err; + + unionfs_read_lock(file->f_path.dentry->d_sb); + + err = unionfs_file_revalidate(file, true); + if (unlikely(err)) + goto out; + + /* check if asked for local commands */ + switch (cmd) { + case UNIONFS_IOCTL_INCGEN: + /* Increment the superblock generation count */ + pr_info("unionfs: incgen ioctl deprecated; " + "use \"-o remount,incgen\"\n"); + err = -ENOSYS; + break; + + case UNIONFS_IOCTL_QUERYFILE: + /* Return list of branches containing the given file */ + err = unionfs_ioctl_queryfile(file, cmd, arg); + break; + + default: + /* pass the ioctl down */ + err = do_ioctl(file, cmd, arg); + break; + } + +out: + unionfs_check_file(file); + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +int unionfs_flush(struct file *file, fl_owner_t id) +{ + int err = 0; + struct file *lower_file = NULL; + struct dentry *dentry = file->f_path.dentry; + int bindex, bstart, bend; + + unionfs_read_lock(dentry->d_sb); + + err = unionfs_file_revalidate(file, true); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + bstart = fbstart(file); + bend = fbend(file); + for (bindex = bstart; bindex <= bend; bindex++) { + lower_file = unionfs_lower_file_idx(file, bindex); + + if (lower_file && lower_file->f_op && + lower_file->f_op->flush) { + err = lower_file->f_op->flush(lower_file, id); + if (err) + goto out; + } + + } + + /* on success, update our times */ + unionfs_copy_attr_times(dentry->d_inode); + /* parent time could have changed too (async) */ + unionfs_copy_attr_times(dentry->d_parent->d_inode); + +out: + unionfs_check_file(file); + unionfs_read_unlock(dentry->d_sb); + return err; +} diff -puN /dev/null fs/unionfs/copyup.c --- /dev/null +++ a/fs/unionfs/copyup.c @@ -0,0 +1,897 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * For detailed explanation of copyup see: + * Documentation/filesystems/unionfs/concepts.txt + */ + +#ifdef CONFIG_UNION_FS_XATTR +/* copyup all extended attrs for a given dentry */ +static int copyup_xattrs(struct dentry *old_lower_dentry, + struct dentry *new_lower_dentry) +{ + int err = 0; + ssize_t list_size = -1; + char *name_list = NULL; + char *attr_value = NULL; + char *name_list_buf = NULL; + + /* query the actual size of the xattr list */ + list_size = vfs_listxattr(old_lower_dentry, NULL, 0); + if (list_size <= 0) { + err = list_size; + goto out; + } + + /* allocate space for the actual list */ + name_list = unionfs_xattr_alloc(list_size + 1, XATTR_LIST_MAX); + if (unlikely(!name_list || IS_ERR(name_list))) { + err = PTR_ERR(name_list); + goto out; + } + + name_list_buf = name_list; /* save for kfree at end */ + + /* now get the actual xattr list of the source file */ + list_size = vfs_listxattr(old_lower_dentry, name_list, list_size); + if (list_size <= 0) { + err = list_size; + goto out; + } + + /* allocate space to hold each xattr's value */ + attr_value = unionfs_xattr_alloc(XATTR_SIZE_MAX, XATTR_SIZE_MAX); + if (unlikely(!attr_value || IS_ERR(attr_value))) { + err = PTR_ERR(name_list); + goto out; + } + + /* in a loop, get and set each xattr from src to dst file */ + while (*name_list) { + ssize_t size; + + /* Lock here since vfs_getxattr doesn't lock for us */ + mutex_lock(&old_lower_dentry->d_inode->i_mutex); + size = vfs_getxattr(old_lower_dentry, name_list, + attr_value, XATTR_SIZE_MAX); + mutex_unlock(&old_lower_dentry->d_inode->i_mutex); + if (size < 0) { + err = size; + goto out; + } + if (size > XATTR_SIZE_MAX) { + err = -E2BIG; + goto out; + } + /* Don't lock here since vfs_setxattr does it for us. */ + err = vfs_setxattr(new_lower_dentry, name_list, attr_value, + size, 0); + /* + * Selinux depends on "security.*" xattrs, so to maintain + * the security of copied-up files, if Selinux is active, + * then we must copy these xattrs as well. So we need to + * temporarily get FOWNER privileges. + * XXX: move entire copyup code to SIOQ. + */ + if (err == -EPERM && !capable(CAP_FOWNER)) { + cap_raise(current->cap_effective, CAP_FOWNER); + err = vfs_setxattr(new_lower_dentry, name_list, + attr_value, size, 0); + cap_lower(current->cap_effective, CAP_FOWNER); + } + if (err < 0) + goto out; + name_list += strlen(name_list) + 1; + } +out: + unionfs_xattr_kfree(name_list_buf); + unionfs_xattr_kfree(attr_value); + /* Ignore if xattr isn't supported */ + if (err == -ENOTSUPP || err == -EOPNOTSUPP) + err = 0; + return err; +} +#endif /* CONFIG_UNION_FS_XATTR */ + +/* + * Determine the mode based on the copyup flags, and the existing dentry. + * + * Handle file systems which may not support certain options. For example + * jffs2 doesn't allow one to chmod a symlink. So we ignore such harmless + * errors, rather than propagating them up, which results in copyup errors + * and errors returned back to users. + */ +static int copyup_permissions(struct super_block *sb, + struct dentry *old_lower_dentry, + struct dentry *new_lower_dentry) +{ + struct inode *i = old_lower_dentry->d_inode; + struct iattr newattrs; + int err; + + newattrs.ia_atime = i->i_atime; + newattrs.ia_mtime = i->i_mtime; + newattrs.ia_ctime = i->i_ctime; + newattrs.ia_gid = i->i_gid; + newattrs.ia_uid = i->i_uid; + newattrs.ia_valid = ATTR_CTIME | ATTR_ATIME | ATTR_MTIME | + ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_FORCE | + ATTR_GID | ATTR_UID; + err = notify_change(new_lower_dentry, &newattrs); + if (err) + goto out; + + /* now try to change the mode and ignore EOPNOTSUPP on symlinks */ + newattrs.ia_mode = i->i_mode; + newattrs.ia_valid = ATTR_MODE | ATTR_FORCE; + err = notify_change(new_lower_dentry, &newattrs); + if (err == -EOPNOTSUPP && + S_ISLNK(new_lower_dentry->d_inode->i_mode)) { + printk(KERN_WARNING + "unionfs: changing \"%s\" symlink mode unsupported\n", + new_lower_dentry->d_name.name); + err = 0; + } + +out: + return err; +} + +/* + * create the new device/file/directory - use copyup_permission to copyup + * times, and mode + * + * if the object being copied up is a regular file, the file is only created, + * the contents have to be copied up separately + */ +static int __copyup_ndentry(struct dentry *old_lower_dentry, + struct dentry *new_lower_dentry, + struct dentry *new_lower_parent_dentry, + char *symbuf) +{ + int err = 0; + umode_t old_mode = old_lower_dentry->d_inode->i_mode; + struct sioq_args args; + + if (S_ISDIR(old_mode)) { + args.mkdir.parent = new_lower_parent_dentry->d_inode; + args.mkdir.dentry = new_lower_dentry; + args.mkdir.mode = old_mode; + + run_sioq(__unionfs_mkdir, &args); + err = args.err; + } else if (S_ISLNK(old_mode)) { + args.symlink.parent = new_lower_parent_dentry->d_inode; + args.symlink.dentry = new_lower_dentry; + args.symlink.symbuf = symbuf; + args.symlink.mode = old_mode; + + run_sioq(__unionfs_symlink, &args); + err = args.err; + } else if (S_ISBLK(old_mode) || S_ISCHR(old_mode) || + S_ISFIFO(old_mode) || S_ISSOCK(old_mode)) { + args.mknod.parent = new_lower_parent_dentry->d_inode; + args.mknod.dentry = new_lower_dentry; + args.mknod.mode = old_mode; + args.mknod.dev = old_lower_dentry->d_inode->i_rdev; + + run_sioq(__unionfs_mknod, &args); + err = args.err; + } else if (S_ISREG(old_mode)) { + struct nameidata nd; + err = init_lower_nd(&nd, LOOKUP_CREATE); + if (unlikely(err < 0)) + goto out; + args.create.nd = &nd; + args.create.parent = new_lower_parent_dentry->d_inode; + args.create.dentry = new_lower_dentry; + args.create.mode = old_mode; + + run_sioq(__unionfs_create, &args); + err = args.err; + release_lower_nd(&nd, err); + } else { + printk(KERN_CRIT "unionfs: unknown inode type %d\n", + old_mode); + BUG(); + } + +out: + return err; +} + +static int __copyup_reg_data(struct dentry *dentry, + struct dentry *new_lower_dentry, int new_bindex, + struct dentry *old_lower_dentry, int old_bindex, + struct file **copyup_file, loff_t len) +{ + struct super_block *sb = dentry->d_sb; + struct file *input_file; + struct file *output_file; + struct vfsmount *output_mnt; + mm_segment_t old_fs; + char *buf = NULL; + ssize_t read_bytes, write_bytes; + loff_t size; + int err = 0; + + /* open old file */ + unionfs_mntget(dentry, old_bindex); + branchget(sb, old_bindex); + /* dentry_open calls dput and mntput if it returns an error */ + input_file = dentry_open(old_lower_dentry, + unionfs_lower_mnt_idx(dentry, old_bindex), + O_RDONLY | O_LARGEFILE); + if (IS_ERR(input_file)) { + dput(old_lower_dentry); + err = PTR_ERR(input_file); + goto out; + } + if (unlikely(!input_file->f_op || !input_file->f_op->read)) { + err = -EINVAL; + goto out_close_in; + } + + /* open new file */ + dget(new_lower_dentry); + output_mnt = unionfs_mntget(sb->s_root, new_bindex); + branchget(sb, new_bindex); + output_file = dentry_open(new_lower_dentry, output_mnt, + O_RDWR | O_LARGEFILE); + if (IS_ERR(output_file)) { + err = PTR_ERR(output_file); + goto out_close_in2; + } + if (unlikely(!output_file->f_op || !output_file->f_op->write)) { + err = -EINVAL; + goto out_close_out; + } + + /* allocating a buffer */ + buf = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (unlikely(!buf)) { + err = -ENOMEM; + goto out_close_out; + } + + input_file->f_pos = 0; + output_file->f_pos = 0; + + old_fs = get_fs(); + set_fs(KERNEL_DS); + + size = len; + err = 0; + do { + if (len >= PAGE_SIZE) + size = PAGE_SIZE; + else if ((len < PAGE_SIZE) && (len > 0)) + size = len; + + len -= PAGE_SIZE; + + read_bytes = + input_file->f_op->read(input_file, + (char __user *)buf, size, + &input_file->f_pos); + if (read_bytes <= 0) { + err = read_bytes; + break; + } + + write_bytes = + output_file->f_op->write(output_file, + (char __user *)buf, + read_bytes, + &output_file->f_pos); + if ((write_bytes < 0) || (write_bytes < read_bytes)) { + err = write_bytes; + break; + } + } while ((read_bytes > 0) && (len > 0)); + + set_fs(old_fs); + + kfree(buf); + + if (!err) + err = output_file->f_op->fsync(output_file, + new_lower_dentry, 0); + + if (err) + goto out_close_out; + + if (copyup_file) { + *copyup_file = output_file; + goto out_close_in; + } + +out_close_out: + fput(output_file); + +out_close_in2: + branchput(sb, new_bindex); + +out_close_in: + fput(input_file); + +out: + branchput(sb, old_bindex); + + return err; +} + +/* + * dput the lower references for old and new dentry & clear a lower dentry + * pointer + */ +static void __clear(struct dentry *dentry, struct dentry *old_lower_dentry, + int old_bstart, int old_bend, + struct dentry *new_lower_dentry, int new_bindex) +{ + /* get rid of the lower dentry and all its traces */ + unionfs_set_lower_dentry_idx(dentry, new_bindex, NULL); + set_dbstart(dentry, old_bstart); + set_dbend(dentry, old_bend); + + dput(new_lower_dentry); + dput(old_lower_dentry); +} + +/* + * Copy up a dentry to a file of specified name. + * + * @dir: used to pull the ->i_sb to access other branches + * @dentry: the non-negative dentry whose lower_inode we should copy + * @bstart: the branch of the lower_inode to copy from + * @new_bindex: the branch to create the new file in + * @name: the name of the file to create + * @namelen: length of @name + * @copyup_file: the "struct file" to return (optional) + * @len: how many bytes to copy-up? + */ +int copyup_dentry(struct inode *dir, struct dentry *dentry, int bstart, + int new_bindex, const char *name, int namelen, + struct file **copyup_file, loff_t len) +{ + struct dentry *new_lower_dentry; + struct dentry *old_lower_dentry = NULL; + struct super_block *sb; + int err = 0; + int old_bindex; + int old_bstart; + int old_bend; + struct dentry *new_lower_parent_dentry = NULL; + mm_segment_t oldfs; + char *symbuf = NULL; + + verify_locked(dentry); + + old_bindex = bstart; + old_bstart = dbstart(dentry); + old_bend = dbend(dentry); + + BUG_ON(new_bindex < 0); + BUG_ON(new_bindex >= old_bindex); + + sb = dir->i_sb; + + err = is_robranch_super(sb, new_bindex); + if (err) + goto out; + + /* Create the directory structure above this dentry. */ + new_lower_dentry = create_parents(dir, dentry, name, new_bindex); + if (IS_ERR(new_lower_dentry)) { + err = PTR_ERR(new_lower_dentry); + goto out; + } + + old_lower_dentry = unionfs_lower_dentry_idx(dentry, old_bindex); + /* we conditionally dput this old_lower_dentry at end of function */ + dget(old_lower_dentry); + + /* For symlinks, we must read the link before we lock the directory. */ + if (S_ISLNK(old_lower_dentry->d_inode->i_mode)) { + + symbuf = kmalloc(PATH_MAX, GFP_KERNEL); + if (unlikely(!symbuf)) { + __clear(dentry, old_lower_dentry, + old_bstart, old_bend, + new_lower_dentry, new_bindex); + err = -ENOMEM; + goto out_free; + } + + oldfs = get_fs(); + set_fs(KERNEL_DS); + err = old_lower_dentry->d_inode->i_op->readlink( + old_lower_dentry, + (char __user *)symbuf, + PATH_MAX); + set_fs(oldfs); + if (err < 0) { + __clear(dentry, old_lower_dentry, + old_bstart, old_bend, + new_lower_dentry, new_bindex); + goto out_free; + } + symbuf[err] = '\0'; + } + + /* Now we lock the parent, and create the object in the new branch. */ + new_lower_parent_dentry = lock_parent(new_lower_dentry); + + /* create the new inode */ + err = __copyup_ndentry(old_lower_dentry, new_lower_dentry, + new_lower_parent_dentry, symbuf); + + if (err) { + __clear(dentry, old_lower_dentry, + old_bstart, old_bend, + new_lower_dentry, new_bindex); + goto out_unlock; + } + + /* We actually copyup the file here. */ + if (S_ISREG(old_lower_dentry->d_inode->i_mode)) + err = __copyup_reg_data(dentry, new_lower_dentry, new_bindex, + old_lower_dentry, old_bindex, + copyup_file, len); + if (err) + goto out_unlink; + + /* Set permissions. */ + err = copyup_permissions(sb, old_lower_dentry, new_lower_dentry); + if (err) + goto out_unlink; + +#ifdef CONFIG_UNION_FS_XATTR + /* Selinux uses extended attributes for permissions. */ + err = copyup_xattrs(old_lower_dentry, new_lower_dentry); + if (err) + goto out_unlink; +#endif /* CONFIG_UNION_FS_XATTR */ + + /* do not allow files getting deleted to be re-interposed */ + if (!d_deleted(dentry)) + unionfs_reinterpose(dentry); + + goto out_unlock; + +out_unlink: + /* + * copyup failed, because we possibly ran out of space or + * quota, or something else happened so let's unlink; we don't + * really care about the return value of vfs_unlink + */ + vfs_unlink(new_lower_parent_dentry->d_inode, new_lower_dentry); + + if (copyup_file) { + /* need to close the file */ + + fput(*copyup_file); + branchput(sb, new_bindex); + } + + /* + * TODO: should we reset the error to something like -EIO? + * + * If we don't reset, the user may get some nonsensical errors, but + * on the other hand, if we reset to EIO, we guarantee that the user + * will get a "confusing" error message. + */ + +out_unlock: + unlock_dir(new_lower_parent_dentry); + +out_free: + /* + * If old_lower_dentry was a directory, we need to dput it. If it + * was a file, then it was already dput indirectly by other + * functions we call above which operate on regular files. + */ + if (old_lower_dentry && old_lower_dentry->d_inode && + (S_ISDIR(old_lower_dentry->d_inode->i_mode) || + S_ISLNK(old_lower_dentry->d_inode->i_mode))) + dput(old_lower_dentry); + kfree(symbuf); + + if (err) + goto out; + if (!S_ISDIR(dentry->d_inode->i_mode)) { + unionfs_postcopyup_release(dentry); + if (!unionfs_lower_inode(dentry->d_inode)) { + /* + * If we got here, then we copied up to an + * unlinked-open file, whose name is .unionfsXXXXX. + */ + struct inode *inode = new_lower_dentry->d_inode; + atomic_inc(&inode->i_count); + unionfs_set_lower_inode_idx(dentry->d_inode, + ibstart(dentry->d_inode), + inode); + } + } + unionfs_postcopyup_setmnt(dentry); + /* sync inode times from copied-up inode to our inode */ + unionfs_copy_attr_times(dentry->d_inode); + unionfs_check_inode(dir); + unionfs_check_dentry(dentry); +out: + return err; +} + +/* + * This function creates a copy of a file represented by 'file' which + * currently resides in branch 'bstart' to branch 'new_bindex.' The copy + * will be named "name". + */ +int copyup_named_file(struct inode *dir, struct file *file, char *name, + int bstart, int new_bindex, loff_t len) +{ + int err = 0; + struct file *output_file = NULL; + + err = copyup_dentry(dir, file->f_path.dentry, bstart, new_bindex, + name, strlen(name), &output_file, len); + if (!err) { + fbstart(file) = new_bindex; + unionfs_set_lower_file_idx(file, new_bindex, output_file); + } + + return err; +} + +/* + * This function creates a copy of a file represented by 'file' which + * currently resides in branch 'bstart' to branch 'new_bindex'. + */ +int copyup_file(struct inode *dir, struct file *file, int bstart, + int new_bindex, loff_t len) +{ + int err = 0; + struct file *output_file = NULL; + struct dentry *dentry = file->f_path.dentry; + + err = copyup_dentry(dir, dentry, bstart, new_bindex, + dentry->d_name.name, dentry->d_name.len, + &output_file, len); + if (!err) { + fbstart(file) = new_bindex; + unionfs_set_lower_file_idx(file, new_bindex, output_file); + } + + return err; +} + +/* purge a dentry's lower-branch states (dput/mntput, etc.) */ +static void __cleanup_dentry(struct dentry *dentry, int bindex, + int old_bstart, int old_bend) +{ + int loop_start; + int loop_end; + int new_bstart = -1; + int new_bend = -1; + int i; + + loop_start = min(old_bstart, bindex); + loop_end = max(old_bend, bindex); + + /* + * This loop sets the bstart and bend for the new dentry by + * traversing from left to right. It also dputs all negative + * dentries except bindex + */ + for (i = loop_start; i <= loop_end; i++) { + if (!unionfs_lower_dentry_idx(dentry, i)) + continue; + + if (i == bindex) { + new_bend = i; + if (new_bstart < 0) + new_bstart = i; + continue; + } + + if (!unionfs_lower_dentry_idx(dentry, i)->d_inode) { + dput(unionfs_lower_dentry_idx(dentry, i)); + unionfs_set_lower_dentry_idx(dentry, i, NULL); + + unionfs_mntput(dentry, i); + unionfs_set_lower_mnt_idx(dentry, i, NULL); + } else { + if (new_bstart < 0) + new_bstart = i; + new_bend = i; + } + } + + if (new_bstart < 0) + new_bstart = bindex; + if (new_bend < 0) + new_bend = bindex; + set_dbstart(dentry, new_bstart); + set_dbend(dentry, new_bend); + +} + +/* set lower inode ptr and update bstart & bend if necessary */ +static void __set_inode(struct dentry *upper, struct dentry *lower, + int bindex) +{ + unionfs_set_lower_inode_idx(upper->d_inode, bindex, + igrab(lower->d_inode)); + if (likely(ibstart(upper->d_inode) > bindex)) + ibstart(upper->d_inode) = bindex; + if (likely(ibend(upper->d_inode) < bindex)) + ibend(upper->d_inode) = bindex; + +} + +/* set lower dentry ptr and update bstart & bend if necessary */ +static void __set_dentry(struct dentry *upper, struct dentry *lower, + int bindex) +{ + unionfs_set_lower_dentry_idx(upper, bindex, lower); + if (likely(dbstart(upper) > bindex)) + set_dbstart(upper, bindex); + if (likely(dbend(upper) < bindex)) + set_dbend(upper, bindex); +} + +/* + * This function replicates the directory structure up-to given dentry + * in the bindex branch. + */ +struct dentry *create_parents(struct inode *dir, struct dentry *dentry, + const char *name, int bindex) +{ + int err; + struct dentry *child_dentry; + struct dentry *parent_dentry; + struct dentry *lower_parent_dentry = NULL; + struct dentry *lower_dentry = NULL; + const char *childname; + unsigned int childnamelen; + int nr_dentry; + int count = 0; + int old_bstart; + int old_bend; + struct dentry **path = NULL; + struct super_block *sb; + + verify_locked(dentry); + + err = is_robranch_super(dir->i_sb, bindex); + if (err) { + lower_dentry = ERR_PTR(err); + goto out; + } + + old_bstart = dbstart(dentry); + old_bend = dbend(dentry); + + lower_dentry = ERR_PTR(-ENOMEM); + + /* There is no sense allocating any less than the minimum. */ + nr_dentry = 1; + path = kmalloc(nr_dentry * sizeof(struct dentry *), GFP_KERNEL); + if (unlikely(!path)) + goto out; + + /* assume the negative dentry of unionfs as the parent dentry */ + parent_dentry = dentry; + + /* + * This loop finds the first parent that exists in the given branch. + * We start building the directory structure from there. At the end + * of the loop, the following should hold: + * - child_dentry is the first nonexistent child + * - parent_dentry is the first existent parent + * - path[0] is the = deepest child + * - path[count] is the first child to create + */ + do { + child_dentry = parent_dentry; + + /* find the parent directory dentry in unionfs */ + parent_dentry = child_dentry->d_parent; + unionfs_lock_dentry(parent_dentry); + + /* find out the lower_parent_dentry in the given branch */ + lower_parent_dentry = + unionfs_lower_dentry_idx(parent_dentry, bindex); + + /* grow path table */ + if (count == nr_dentry) { + void *p; + + nr_dentry *= 2; + p = krealloc(path, nr_dentry * sizeof(struct dentry *), + GFP_KERNEL); + if (unlikely(!p)) { + lower_dentry = ERR_PTR(-ENOMEM); + goto out; + } + path = p; + } + + /* store the child dentry */ + path[count++] = child_dentry; + } while (!lower_parent_dentry); + count--; + + sb = dentry->d_sb; + + /* + * This code goes between the begin/end labels and basically + * emulates a while(child_dentry != dentry), only cleaner and + * shorter than what would be a much longer while loop. + */ +begin: + /* get lower parent dir in the current branch */ + lower_parent_dentry = unionfs_lower_dentry_idx(parent_dentry, bindex); + unionfs_unlock_dentry(parent_dentry); + + /* init the values to lookup */ + childname = child_dentry->d_name.name; + childnamelen = child_dentry->d_name.len; + + if (child_dentry != dentry) { + /* lookup child in the underlying file system */ + lower_dentry = lookup_one_len(childname, lower_parent_dentry, + childnamelen); + if (IS_ERR(lower_dentry)) + goto out; + } else { + /* + * Is the name a whiteout of the child name ? lookup the + * whiteout child in the underlying file system + */ + lower_dentry = lookup_one_len(name, lower_parent_dentry, + strlen(name)); + if (IS_ERR(lower_dentry)) + goto out; + + /* Replace the current dentry (if any) with the new one */ + dput(unionfs_lower_dentry_idx(dentry, bindex)); + unionfs_set_lower_dentry_idx(dentry, bindex, + lower_dentry); + + __cleanup_dentry(dentry, bindex, old_bstart, old_bend); + goto out; + } + + if (lower_dentry->d_inode) { + /* + * since this already exists we dput to avoid + * multiple references on the same dentry + */ + dput(lower_dentry); + } else { + struct sioq_args args; + + /* it's a negative dentry, create a new dir */ + lower_parent_dentry = lock_parent(lower_dentry); + + args.mkdir.parent = lower_parent_dentry->d_inode; + args.mkdir.dentry = lower_dentry; + args.mkdir.mode = child_dentry->d_inode->i_mode; + + run_sioq(__unionfs_mkdir, &args); + err = args.err; + + if (!err) + err = copyup_permissions(dir->i_sb, child_dentry, + lower_dentry); + unlock_dir(lower_parent_dentry); + if (err) { + struct inode *inode = lower_dentry->d_inode; + /* + * If we get here, it means that we created a new + * dentry+inode, but copying permissions failed. + * Therefore, we should delete this inode and dput + * the dentry so as not to leave cruft behind. + */ + if (lower_dentry->d_op && lower_dentry->d_op->d_iput) + lower_dentry->d_op->d_iput(lower_dentry, + inode); + else + iput(inode); + lower_dentry->d_inode = NULL; + dput(lower_dentry); + lower_dentry = ERR_PTR(err); + goto out; + } + + } + + __set_inode(child_dentry, lower_dentry, bindex); + __set_dentry(child_dentry, lower_dentry, bindex); + /* + * update times of this dentry, but also the parent, because if + * we changed, the parent may have changed too. + */ + unionfs_copy_attr_times(parent_dentry->d_inode); + unionfs_copy_attr_times(child_dentry->d_inode); + + parent_dentry = child_dentry; + child_dentry = path[--count]; + goto begin; +out: + /* cleanup any leftover locks from the do/while loop above */ + if (IS_ERR(lower_dentry)) + while (count) + unionfs_unlock_dentry(path[count--]); + kfree(path); + return lower_dentry; +} + +/* + * Post-copyup helper to ensure we have valid mnts: set lower mnt of + * dentry+parents to the first parent node that has an mnt. + */ +void unionfs_postcopyup_setmnt(struct dentry *dentry) +{ + struct dentry *parent, *hasone; + int bindex = dbstart(dentry); + + if (unionfs_lower_mnt_idx(dentry, bindex)) + return; + hasone = dentry->d_parent; + /* this loop should stop at root dentry */ + while (!unionfs_lower_mnt_idx(hasone, bindex)) + hasone = hasone->d_parent; + parent = dentry; + while (!unionfs_lower_mnt_idx(parent, bindex)) { + unionfs_set_lower_mnt_idx(parent, bindex, + unionfs_mntget(hasone, bindex)); + parent = parent->d_parent; + } +} + +/* + * Post-copyup helper to release all non-directory source objects of a + * copied-up file. Regular files should have only one lower object. + */ +void unionfs_postcopyup_release(struct dentry *dentry) +{ + int bindex; + + BUG_ON(S_ISDIR(dentry->d_inode->i_mode)); + for (bindex = dbstart(dentry)+1; bindex <= dbend(dentry); bindex++) { + if (unionfs_lower_mnt_idx(dentry, bindex)) { + unionfs_mntput(dentry, bindex); + unionfs_set_lower_mnt_idx(dentry, bindex, NULL); + } + if (unionfs_lower_dentry_idx(dentry, bindex)) { + dput(unionfs_lower_dentry_idx(dentry, bindex)); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + iput(unionfs_lower_inode_idx(dentry->d_inode, bindex)); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, + NULL); + } + } + bindex = dbstart(dentry); + set_dbend(dentry, bindex); + ibend(dentry->d_inode) = ibstart(dentry->d_inode) = bindex; +} diff -puN /dev/null fs/unionfs/debug.c --- /dev/null +++ a/fs/unionfs/debug.c @@ -0,0 +1,532 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * Helper debugging functions for maintainers (and for users to report back + * useful information back to maintainers) + */ + +/* it's always useful to know what part of the code called us */ +#define PRINT_CALLER(fname, fxn, line) \ + do { \ + if (!printed_caller) { \ + pr_debug("PC:%s:%s:%d\n", (fname), (fxn), (line)); \ + printed_caller = 1; \ + } \ + } while (0) + +/* + * __unionfs_check_{inode,dentry,file} perform exhaustive sanity checking on + * the fan-out of various Unionfs objects. We check that no lower objects + * exist outside the start/end branch range; that all objects within are + * non-NULL (with some allowed exceptions); that for every lower file + * there's a lower dentry+inode; that the start/end ranges match for all + * corresponding lower objects; that open files/symlinks have only one lower + * objects, but directories can have several; and more. + */ +void __unionfs_check_inode(const struct inode *inode, + const char *fname, const char *fxn, int line) +{ + int bindex; + int istart, iend; + struct inode *lower_inode; + struct super_block *sb; + int printed_caller = 0; + void *poison_ptr; + + /* for inodes now */ + BUG_ON(!inode); + sb = inode->i_sb; + istart = ibstart(inode); + iend = ibend(inode); + /* don't check inode if no lower branches */ + if (istart < 0 && iend < 0) + return; + if (unlikely(istart > iend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci0: inode=%p istart/end=%d:%d\n", + inode, istart, iend); + } + if (unlikely((istart == -1 && iend != -1) || + (istart != -1 && iend == -1))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci1: inode=%p istart/end=%d:%d\n", + inode, istart, iend); + } + if (!S_ISDIR(inode->i_mode)) { + if (unlikely(iend != istart)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci2: inode=%p istart=%d iend=%d\n", + inode, istart, iend); + } + } + + for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) { + if (unlikely(!UNIONFS_I(inode))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci3: no inode_info %p\n", inode); + return; + } + if (unlikely(!UNIONFS_I(inode)->lower_inodes)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci4: no lower_inodes %p\n", inode); + return; + } + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (lower_inode) { + memset(&poison_ptr, POISON_INUSE, sizeof(void *)); + if (unlikely(bindex < istart || bindex > iend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci5: inode/linode=%p:%p bindex=%d " + "istart/end=%d:%d\n", inode, + lower_inode, bindex, istart, iend); + } else if (unlikely(lower_inode == poison_ptr)) { + /* freed inode! */ + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci6: inode/linode=%p:%p bindex=%d " + "istart/end=%d:%d\n", inode, + lower_inode, bindex, istart, iend); + } + continue; + } + /* if we get here, then lower_inode == NULL */ + if (bindex < istart || bindex > iend) + continue; + /* + * directories can have NULL lower inodes in b/t start/end, + * but NOT if at the start/end range. + */ + if (unlikely(S_ISDIR(inode->i_mode) && + bindex > istart && bindex < iend)) + continue; + PRINT_CALLER(fname, fxn, line); + pr_debug(" Ci7: inode/linode=%p:%p " + "bindex=%d istart/end=%d:%d\n", + inode, lower_inode, bindex, istart, iend); + } +} + +void __unionfs_check_dentry(const struct dentry *dentry, + const char *fname, const char *fxn, int line) +{ + int bindex; + int dstart, dend, istart, iend; + struct dentry *lower_dentry; + struct inode *inode, *lower_inode; + struct super_block *sb; + struct vfsmount *lower_mnt; + int printed_caller = 0; + void *poison_ptr; + + BUG_ON(!dentry); + sb = dentry->d_sb; + inode = dentry->d_inode; + dstart = dbstart(dentry); + dend = dbend(dentry); + /* don't check dentry/mnt if no lower branches */ + if (dstart < 0 && dend < 0) + goto check_inode; + BUG_ON(dstart > dend); + + if (unlikely((dstart == -1 && dend != -1) || + (dstart != -1 && dend == -1))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CD0: dentry=%p dstart/end=%d:%d\n", + dentry, dstart, dend); + } + /* + * check for NULL dentries inside the start/end range, or + * non-NULL dentries outside the start/end range. + */ + for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (lower_dentry) { + if (unlikely(bindex < dstart || bindex > dend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CD1: dentry/lower=%p:%p(%p) " + "bindex=%d dstart/end=%d:%d\n", + dentry, lower_dentry, + (lower_dentry ? lower_dentry->d_inode : + (void *) -1L), + bindex, dstart, dend); + } + } else { /* lower_dentry == NULL */ + if (bindex < dstart || bindex > dend) + continue; + /* + * Directories can have NULL lower inodes in b/t + * start/end, but NOT if at the start/end range. + * Ignore this rule, however, if this is a NULL + * dentry or a deleted dentry. + */ + if (unlikely(!d_deleted((struct dentry *) dentry) && + inode && + !(inode && S_ISDIR(inode->i_mode) && + bindex > dstart && bindex < dend))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CD2: dentry/lower=%p:%p(%p) " + "bindex=%d dstart/end=%d:%d\n", + dentry, lower_dentry, + (lower_dentry ? + lower_dentry->d_inode : + (void *) -1L), + bindex, dstart, dend); + } + } + } + + /* check for vfsmounts same as for dentries */ + for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) { + lower_mnt = unionfs_lower_mnt_idx(dentry, bindex); + if (lower_mnt) { + if (unlikely(bindex < dstart || bindex > dend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CM0: dentry/lmnt=%p:%p bindex=%d " + "dstart/end=%d:%d\n", dentry, + lower_mnt, bindex, dstart, dend); + } + } else { /* lower_mnt == NULL */ + if (bindex < dstart || bindex > dend) + continue; + /* + * Directories can have NULL lower inodes in b/t + * start/end, but NOT if at the start/end range. + * Ignore this rule, however, if this is a NULL + * dentry. + */ + if (unlikely(inode && + !(inode && S_ISDIR(inode->i_mode) && + bindex > dstart && bindex < dend))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CM1: dentry/lmnt=%p:%p " + "bindex=%d dstart/end=%d:%d\n", + dentry, lower_mnt, bindex, + dstart, dend); + } + } + } + +check_inode: + /* for inodes now */ + if (!inode) + return; + istart = ibstart(inode); + iend = ibend(inode); + /* don't check inode if no lower branches */ + if (istart < 0 && iend < 0) + return; + BUG_ON(istart > iend); + if (unlikely((istart == -1 && iend != -1) || + (istart != -1 && iend == -1))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI0: dentry/inode=%p:%p istart/end=%d:%d\n", + dentry, inode, istart, iend); + } + if (unlikely(istart != dstart)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI1: dentry/inode=%p:%p istart=%d dstart=%d\n", + dentry, inode, istart, dstart); + } + if (unlikely(iend != dend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI2: dentry/inode=%p:%p iend=%d dend=%d\n", + dentry, inode, iend, dend); + } + + if (!S_ISDIR(inode->i_mode)) { + if (unlikely(dend != dstart)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI3: dentry/inode=%p:%p dstart=%d dend=%d\n", + dentry, inode, dstart, dend); + } + if (unlikely(iend != istart)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI4: dentry/inode=%p:%p istart=%d iend=%d\n", + dentry, inode, istart, iend); + } + } + + for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (lower_inode) { + memset(&poison_ptr, POISON_INUSE, sizeof(void *)); + if (unlikely(bindex < istart || bindex > iend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI5: dentry/linode=%p:%p bindex=%d " + "istart/end=%d:%d\n", dentry, + lower_inode, bindex, istart, iend); + } else if (unlikely(lower_inode == poison_ptr)) { + /* freed inode! */ + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI6: dentry/linode=%p:%p bindex=%d " + "istart/end=%d:%d\n", dentry, + lower_inode, bindex, istart, iend); + } + continue; + } + /* if we get here, then lower_inode == NULL */ + if (bindex < istart || bindex > iend) + continue; + /* + * directories can have NULL lower inodes in b/t start/end, + * but NOT if at the start/end range. + */ + if (unlikely(S_ISDIR(inode->i_mode) && + bindex > istart && bindex < iend)) + continue; + PRINT_CALLER(fname, fxn, line); + pr_debug(" CI7: dentry/linode=%p:%p " + "bindex=%d istart/end=%d:%d\n", + dentry, lower_inode, bindex, istart, iend); + } + + /* + * If it's a directory, then intermediate objects b/t start/end can + * be NULL. But, check that all three are NULL: lower dentry, mnt, + * and inode. + */ + if (dstart >= 0 && dend >= 0 && S_ISDIR(inode->i_mode)) + for (bindex = dstart+1; bindex < dend; bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + lower_dentry = unionfs_lower_dentry_idx(dentry, + bindex); + lower_mnt = unionfs_lower_mnt_idx(dentry, bindex); + if (unlikely(!((lower_inode && lower_dentry && + lower_mnt) || + (!lower_inode && + !lower_dentry && !lower_mnt)))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" Cx: lmnt/ldentry/linode=%p:%p:%p " + "bindex=%d dstart/end=%d:%d\n", + lower_mnt, lower_dentry, lower_inode, + bindex, dstart, dend); + } + } + /* check if lower inode is newer than upper one (it shouldn't) */ + if (unlikely(is_newer_lower(dentry))) { + PRINT_CALLER(fname, fxn, line); + for (bindex = ibstart(inode); bindex <= ibend(inode); + bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (unlikely(!lower_inode)) + continue; + pr_debug(" CI8: bindex=%d mtime/lmtime=%lu.%lu/%lu.%lu " + "ctime/lctime=%lu.%lu/%lu.%lu\n", + bindex, + inode->i_mtime.tv_sec, + inode->i_mtime.tv_nsec, + lower_inode->i_mtime.tv_sec, + lower_inode->i_mtime.tv_nsec, + inode->i_ctime.tv_sec, + inode->i_ctime.tv_nsec, + lower_inode->i_ctime.tv_sec, + lower_inode->i_ctime.tv_nsec); + } + } +} + +void __unionfs_check_file(const struct file *file, + const char *fname, const char *fxn, int line) +{ + int bindex; + int dstart, dend, fstart, fend; + struct dentry *dentry; + struct file *lower_file; + struct inode *inode; + struct super_block *sb; + int printed_caller = 0; + + BUG_ON(!file); + dentry = file->f_path.dentry; + sb = dentry->d_sb; + dstart = dbstart(dentry); + dend = dbend(dentry); + BUG_ON(dstart > dend); + fstart = fbstart(file); + fend = fbend(file); + BUG_ON(fstart > fend); + + if (unlikely((fstart == -1 && fend != -1) || + (fstart != -1 && fend == -1))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CF0: file/dentry=%p:%p fstart/end=%d:%d\n", + file, dentry, fstart, fend); + } + if (unlikely(fstart != dstart)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CF1: file/dentry=%p:%p fstart=%d dstart=%d\n", + file, dentry, fstart, dstart); + } + if (unlikely(fend != dend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CF2: file/dentry=%p:%p fend=%d dend=%d\n", + file, dentry, fend, dend); + } + inode = dentry->d_inode; + if (!S_ISDIR(inode->i_mode)) { + if (unlikely(fend != fstart)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CF3: file/inode=%p:%p fstart=%d fend=%d\n", + file, inode, fstart, fend); + } + if (unlikely(dend != dstart)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CF4: file/dentry=%p:%p dstart=%d dend=%d\n", + file, dentry, dstart, dend); + } + } + + /* + * check for NULL dentries inside the start/end range, or + * non-NULL dentries outside the start/end range. + */ + for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) { + lower_file = unionfs_lower_file_idx(file, bindex); + if (lower_file) { + if (unlikely(bindex < fstart || bindex > fend)) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CF5: file/lower=%p:%p bindex=%d " + "fstart/end=%d:%d\n", file, + lower_file, bindex, fstart, fend); + } + } else { /* lower_file == NULL */ + if (bindex >= fstart && bindex <= fend) { + /* + * directories can have NULL lower inodes in + * b/t start/end, but NOT if at the + * start/end range. + */ + if (unlikely(!(S_ISDIR(inode->i_mode) && + bindex > fstart && + bindex < fend))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CF6: file/lower=%p:%p " + "bindex=%d fstart/end=%d:%d\n", + file, lower_file, bindex, + fstart, fend); + } + } + } + } + + __unionfs_check_dentry(dentry, fname, fxn, line); +} + +void __unionfs_check_nd(const struct nameidata *nd, + const char *fname, const char *fxn, int line) +{ + struct file *file; + int printed_caller = 0; + + if (unlikely(!nd)) + return; + if (nd->flags & LOOKUP_OPEN) { + file = nd->intent.open.file; + if (unlikely(file->f_path.dentry && + strcmp(file->f_path.dentry->d_sb->s_type->name, + UNIONFS_NAME))) { + PRINT_CALLER(fname, fxn, line); + pr_debug(" CND1: lower_file of type %s\n", + file->f_path.dentry->d_sb->s_type->name); + BUG(); + } + } +} + +/* useful to track vfsmount leaks that could cause EBUSY on unmount */ +void __show_branch_counts(const struct super_block *sb, + const char *file, const char *fxn, int line) +{ + int i; + struct vfsmount *mnt; + + pr_debug("BC:"); + for (i = 0; i < sbmax(sb); i++) { + if (likely(sb->s_root)) + mnt = UNIONFS_D(sb->s_root)->lower_paths[i].mnt; + else + mnt = NULL; + pr_debug("%d:", (mnt ? atomic_read(&mnt->mnt_count) : -99)); + } + pr_debug("%s:%s:%d\n", file, fxn, line); +} + +void __show_inode_times(const struct inode *inode, + const char *file, const char *fxn, int line) +{ + struct inode *lower_inode; + int bindex; + + for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (unlikely(!lower_inode)) + continue; + pr_debug("IT(%lu:%d): ", inode->i_ino, bindex); + pr_debug("%s:%s:%d ", file, fxn, line); + pr_debug("um=%lu/%lu lm=%lu/%lu ", + inode->i_mtime.tv_sec, inode->i_mtime.tv_nsec, + lower_inode->i_mtime.tv_sec, + lower_inode->i_mtime.tv_nsec); + pr_debug("uc=%lu/%lu lc=%lu/%lu\n", + inode->i_ctime.tv_sec, inode->i_ctime.tv_nsec, + lower_inode->i_ctime.tv_sec, + lower_inode->i_ctime.tv_nsec); + } +} + +void __show_dinode_times(const struct dentry *dentry, + const char *file, const char *fxn, int line) +{ + struct inode *inode = dentry->d_inode; + struct inode *lower_inode; + int bindex; + + for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (!lower_inode) + continue; + pr_debug("DT(%s:%lu:%d): ", dentry->d_name.name, inode->i_ino, + bindex); + pr_debug("%s:%s:%d ", file, fxn, line); + pr_debug("um=%lu/%lu lm=%lu/%lu ", + inode->i_mtime.tv_sec, inode->i_mtime.tv_nsec, + lower_inode->i_mtime.tv_sec, + lower_inode->i_mtime.tv_nsec); + pr_debug("uc=%lu/%lu lc=%lu/%lu\n", + inode->i_ctime.tv_sec, inode->i_ctime.tv_nsec, + lower_inode->i_ctime.tv_sec, + lower_inode->i_ctime.tv_nsec); + } +} + +void __show_inode_counts(const struct inode *inode, + const char *file, const char *fxn, int line) +{ + struct inode *lower_inode; + int bindex; + + if (unlikely(!inode)) { + pr_debug("SiC: Null inode\n"); + return; + } + for (bindex = sbstart(inode->i_sb); bindex <= sbend(inode->i_sb); + bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (unlikely(!lower_inode)) + continue; + pr_debug("SIC(%lu:%d:%d): ", inode->i_ino, bindex, + atomic_read(&(inode)->i_count)); + pr_debug("lc=%d ", atomic_read(&(lower_inode)->i_count)); + pr_debug("%s:%s:%d\n", file, fxn, line); + } +} diff -puN /dev/null fs/unionfs/dentry.c --- /dev/null +++ a/fs/unionfs/dentry.c @@ -0,0 +1,509 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * Revalidate a single dentry. + * Assume that dentry's info node is locked. + * Assume that parent(s) are all valid already, but + * the child may not yet be valid. + * Returns true if valid, false otherwise. + */ +static bool __unionfs_d_revalidate_one(struct dentry *dentry, + struct nameidata *nd) +{ + bool valid = true; /* default is valid */ + struct dentry *lower_dentry; + int bindex, bstart, bend; + int sbgen, dgen; + int positive = 0; + int locked = 0; + int interpose_flag; + struct nameidata lowernd; /* TODO: be gentler to the stack */ + + if (nd) + memcpy(&lowernd, nd, sizeof(struct nameidata)); + else + memset(&lowernd, 0, sizeof(struct nameidata)); + + verify_locked(dentry); + + /* if the dentry is unhashed, do NOT revalidate */ + if (d_deleted(dentry)) + goto out; + + BUG_ON(dbstart(dentry) == -1); + if (dentry->d_inode) + positive = 1; + dgen = atomic_read(&UNIONFS_D(dentry)->generation); + sbgen = atomic_read(&UNIONFS_SB(dentry->d_sb)->generation); + /* + * If we are working on an unconnected dentry, then there is no + * revalidation to be done, because this file does not exist within + * the namespace, and Unionfs operates on the namespace, not data. + */ + if (unlikely(sbgen != dgen)) { + struct dentry *result; + int pdgen; + + /* The root entry should always be valid */ + BUG_ON(IS_ROOT(dentry)); + + /* We can't work correctly if our parent isn't valid. */ + pdgen = atomic_read(&UNIONFS_D(dentry->d_parent)->generation); + BUG_ON(pdgen != sbgen); /* should never happen here */ + + /* Free the pointers for our inodes and this dentry. */ + bstart = dbstart(dentry); + bend = dbend(dentry); + if (bstart >= 0) { + struct dentry *lower_dentry; + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = + unionfs_lower_dentry_idx(dentry, + bindex); + dput(lower_dentry); + } + } + set_dbstart(dentry, -1); + set_dbend(dentry, -1); + + interpose_flag = INTERPOSE_REVAL_NEG; + if (positive) { + interpose_flag = INTERPOSE_REVAL; + /* + * During BRM, the VFS could already hold a lock on + * a file being read, so don't lock it again + * (deadlock), but if you lock it in this function, + * then release it here too. + */ + if (!mutex_is_locked(&dentry->d_inode->i_mutex)) { + mutex_lock(&dentry->d_inode->i_mutex); + locked = 1; + } + + bstart = ibstart(dentry->d_inode); + bend = ibend(dentry->d_inode); + if (bstart >= 0) { + struct inode *lower_inode; + for (bindex = bstart; bindex <= bend; + bindex++) { + lower_inode = + unionfs_lower_inode_idx( + dentry->d_inode, + bindex); + iput(lower_inode); + } + } + kfree(UNIONFS_I(dentry->d_inode)->lower_inodes); + UNIONFS_I(dentry->d_inode)->lower_inodes = NULL; + ibstart(dentry->d_inode) = -1; + ibend(dentry->d_inode) = -1; + if (locked) + mutex_unlock(&dentry->d_inode->i_mutex); + } + + result = unionfs_lookup_backend(dentry, &lowernd, + interpose_flag); + if (result) { + if (IS_ERR(result)) { + valid = false; + goto out; + } + /* + * current unionfs_lookup_backend() doesn't return + * a valid dentry + */ + dput(dentry); + dentry = result; + } + + if (unlikely(positive && UNIONFS_I(dentry->d_inode)->stale)) { + make_bad_inode(dentry->d_inode); + d_drop(dentry); + valid = false; + goto out; + } + goto out; + } + + /* The revalidation must occur across all branches */ + bstart = dbstart(dentry); + bend = dbend(dentry); + BUG_ON(bstart == -1); + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry || !lower_dentry->d_op + || !lower_dentry->d_op->d_revalidate) + continue; + /* + * Don't pass nameidata to lower file system, because we + * don't want an arbitrary lower file being opened or + * returned to us: it may be useless to us because of the + * fanout nature of unionfs (cf. file/directory open-file + * invariants). We will open lower files as and when needed + * later on. + */ + if (!lower_dentry->d_op->d_revalidate(lower_dentry, NULL)) + valid = false; + } + + if (!dentry->d_inode) + valid = false; + + if (valid) { + /* + * If we get here, and we copy the meta-data from the lower + * inode to our inode, then it is vital that we have already + * purged all unionfs-level file data. We do that in the + * caller (__unionfs_d_revalidate_chain) by calling + * purge_inode_data. + */ + unionfs_copy_attr_all(dentry->d_inode, + unionfs_lower_inode(dentry->d_inode)); + fsstack_copy_inode_size(dentry->d_inode, + unionfs_lower_inode(dentry->d_inode)); + } + +out: + return valid; +} + +/* + * Determine if the lower inode objects have changed from below the unionfs + * inode. Return true if changed, false otherwise. + * + * We check if the mtime or ctime have changed. However, the inode times + * can be changed by anyone without much protection, including + * asynchronously. This can sometimes cause unionfs to find that the lower + * file system doesn't change its inode times quick enough, resulting in a + * false positive indication (which is harmless, it just makes unionfs do + * extra work in re-validating the objects). To minimize the chances of + * these situations, we still consider such small time changes valid, but we + * don't print debugging messages unless the time changes are greater than + * UNIONFS_MIN_CC_TIME (which defaults to 3 seconds, as with NFS's acregmin) + * because significant changes are more likely due to users manually + * touching lower files. + */ +bool is_newer_lower(const struct dentry *dentry) +{ + int bindex; + struct inode *inode; + struct inode *lower_inode; + + /* ignore if we're called on semi-initialized dentries/inodes */ + if (!dentry || !UNIONFS_D(dentry)) + return false; + inode = dentry->d_inode; + if (!inode || !UNIONFS_I(inode) || + ibstart(inode) < 0 || ibend(inode) < 0) + return false; + + for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (!lower_inode) + continue; + + /* check if mtime/ctime have changed */ + if (unlikely(timespec_compare(&inode->i_mtime, + &lower_inode->i_mtime) < 0)) { + if ((lower_inode->i_mtime.tv_sec - + inode->i_mtime.tv_sec) > UNIONFS_MIN_CC_TIME) { + pr_info("unionfs: new lower inode mtime " + "(bindex=%d, name=%s)\n", bindex, + dentry->d_name.name); + show_dinode_times(dentry); + } + return true; + } + if (unlikely(timespec_compare(&inode->i_ctime, + &lower_inode->i_ctime) < 0)) { + if ((lower_inode->i_ctime.tv_sec - + inode->i_ctime.tv_sec) > UNIONFS_MIN_CC_TIME) { + pr_info("unionfs: new lower inode ctime " + "(bindex=%d, name=%s)\n", bindex, + dentry->d_name.name); + show_dinode_times(dentry); + } + return true; + } + } + return false; /* default: lower is not newer */ +} + +/* + * Purge/remove/unmap all date pages of a unionfs inode. This is called + * when the lower inode has changed, and we have to force processes to get + * the new data. + * + * XXX: Our implementation works in that as long as a user process will have + * caused Unionfs to be called, directly or indirectly, even to just do + * ->d_revalidate; then we will have purged the current Unionfs data and the + * process will see the new data. For example, a process that continually + * re-reads the same file's data will see the NEW data as soon as the lower + * file had changed, upon the next read(2) syscall (even if the file is + * still open!) However, this doesn't work when the process re-reads the + * open file's data via mmap(2) (unless the user unmaps/closes the file and + * remaps/reopens it). Once we respond to ->readpage(s), then the kernel + * maps the page into the process's address space and there doesn't appear + * to be a way to force the kernel to invalidate those pages/mappings, and + * force the process to re-issue ->readpage. If there's a way to invalidate + * active mappings and force a ->readpage, let us know please + * (invalidate_inode_pages2 doesn't do the trick). + */ +static inline void purge_inode_data(struct inode *inode) +{ + /* remove all non-private mappings */ + unmap_mapping_range(inode->i_mapping, 0, 0, 0); + + if (inode->i_data.nrpages) + truncate_inode_pages(&inode->i_data, 0); +} + +void purge_sb_data(struct super_block *sb) +{ + struct inode *inode; + + list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { + if (inode->i_state & (I_FREEING|I_WILL_FREE)) + continue; + purge_inode_data(inode); + } +} + +/* + * Revalidate a parent chain of dentries, then the actual node. + * Assumes that dentry is locked, but will lock all parents if/when needed. + * + * If 'willwrite' is true, and the lower inode times are not in sync, then + * *don't* purge_inode_data, as it could deadlock if ->write calls us and we + * try to truncate a locked page. Besides, if unionfs is about to write + * data to a file, then there's the data unionfs is about to write is more + * authoritative than what's below, therefore we can safely overwrite the + * lower inode times and data. + */ +bool __unionfs_d_revalidate_chain(struct dentry *dentry, struct nameidata *nd, + bool willwrite) +{ + bool valid = false; /* default is invalid */ + struct dentry **chain = NULL; /* chain of dentries to reval */ + int chain_len = 0; + struct dentry *dtmp; + int sbgen, dgen, i; + int saved_bstart, saved_bend, bindex; + + /* find length of chain needed to revalidate */ + /* XXX: should I grab some global (dcache?) lock? */ + chain_len = 0; + sbgen = atomic_read(&UNIONFS_SB(dentry->d_sb)->generation); + dtmp = dentry->d_parent; + dgen = atomic_read(&UNIONFS_D(dtmp)->generation); + /* XXX: should we check if is_newer_lower all the way up? */ + if (unlikely(is_newer_lower(dtmp))) { + /* + * Special case: the root dentry's generation number must + * always be valid, but its lower inode times don't have to + * be, so sync up the times only. + */ + if (IS_ROOT(dtmp)) { + unionfs_copy_attr_times(dtmp->d_inode); + } else { + /* + * reset generation number to zero, guaranteed to be + * "old" + */ + dgen = 0; + atomic_set(&UNIONFS_D(dtmp)->generation, dgen); + } + purge_inode_data(dtmp->d_inode); + } + while (sbgen != dgen) { + /* The root entry should always be valid */ + BUG_ON(IS_ROOT(dtmp)); + chain_len++; + dtmp = dtmp->d_parent; + dgen = atomic_read(&UNIONFS_D(dtmp)->generation); + } + if (chain_len == 0) + goto out_this; /* shortcut if parents are OK */ + + /* + * Allocate array of dentries to reval. We could use linked lists, + * but the number of entries we need to alloc here is often small, + * and short lived, so locality will be better. + */ + chain = kzalloc(chain_len * sizeof(struct dentry *), GFP_KERNEL); + if (unlikely(!chain)) { + printk(KERN_CRIT "unionfs: no more memory in %s\n", + __FUNCTION__); + goto out; + } + + /* + * lock all dentries in chain, in child to parent order. + * if failed, then sleep for a little, then retry. + */ + dtmp = dentry->d_parent; + for (i = chain_len-1; i >= 0; i--) { + chain[i] = dget(dtmp); + dtmp = dtmp->d_parent; + } + + /* + * call __unionfs_d_revalidate_one() on each dentry, but in parent + * to child order. + */ + for (i = 0; i < chain_len; i++) { + unionfs_lock_dentry(chain[i]); + saved_bstart = dbstart(chain[i]); + saved_bend = dbend(chain[i]); + sbgen = atomic_read(&UNIONFS_SB(dentry->d_sb)->generation); + dgen = atomic_read(&UNIONFS_D(chain[i])->generation); + + valid = __unionfs_d_revalidate_one(chain[i], nd); + /* XXX: is this the correct mntput condition?! */ + if (valid && chain_len > 0 && + sbgen != dgen && chain[i]->d_inode && + S_ISDIR(chain[i]->d_inode->i_mode)) { + for (bindex = saved_bstart; bindex <= saved_bend; + bindex++) + unionfs_mntput(chain[i], bindex); + } + unionfs_unlock_dentry(chain[i]); + + if (unlikely(!valid)) + goto out_free; + } + + +out_this: + /* finally, lock this dentry and revalidate it */ + verify_locked(dentry); + dgen = atomic_read(&UNIONFS_D(dentry)->generation); + + if (unlikely(is_newer_lower(dentry))) { + /* root dentry special case as aforementioned */ + if (IS_ROOT(dentry)) { + unionfs_copy_attr_times(dentry->d_inode); + } else { + /* + * reset generation number to zero, guaranteed to be + * "old" + */ + dgen = 0; + atomic_set(&UNIONFS_D(dentry)->generation, dgen); + } + if (!willwrite) + purge_inode_data(dentry->d_inode); + } + valid = __unionfs_d_revalidate_one(dentry, nd); + + /* + * If __unionfs_d_revalidate_one() succeeded above, then it will + * have incremented the refcnt of the mnt's, but also the branch + * indices of the dentry will have been updated (to take into + * account any branch insertions/deletion. So the current + * dbstart/dbend match the current, and new, indices of the mnts + * which __unionfs_d_revalidate_one has incremented. Note: the "if" + * test below does not depend on whether chain_len was 0 or greater. + */ + if (valid && sbgen != dgen) + for (bindex = dbstart(dentry); + bindex <= dbend(dentry); + bindex++) + unionfs_mntput(dentry, bindex); + +out_free: + /* unlock/dput all dentries in chain and return status */ + if (chain_len > 0) { + for (i = 0; i < chain_len; i++) + dput(chain[i]); + kfree(chain); + } +out: + return valid; +} + +static int unionfs_d_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + int err; + + unionfs_read_lock(dentry->d_sb); + + unionfs_lock_dentry(dentry); + err = __unionfs_d_revalidate_chain(dentry, nd, false); + if (likely(err > 0)) { /* true==1: dentry is valid */ + unionfs_check_dentry(dentry); + unionfs_check_nd(nd); + } + unionfs_unlock_dentry(dentry); + + unionfs_read_unlock(dentry->d_sb); + + return err; +} + +/* + * At this point no one can reference this dentry, so we don't have to be + * careful about concurrent access. + */ +static void unionfs_d_release(struct dentry *dentry) +{ + int bindex, bstart, bend; + + unionfs_read_lock(dentry->d_sb); + + unionfs_check_dentry(dentry); + /* this could be a negative dentry, so check first */ + if (unlikely(!UNIONFS_D(dentry))) { + printk(KERN_ERR "unionfs: dentry without private data: %.*s\n", + dentry->d_name.len, dentry->d_name.name); + goto out; + } else if (dbstart(dentry) < 0) + goto out_free; /* due to a (normal) failed lookup */ + + /* Release all the lower dentries */ + bstart = dbstart(dentry); + bend = dbend(dentry); + for (bindex = bstart; bindex <= bend; bindex++) { + dput(unionfs_lower_dentry_idx(dentry, bindex)); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + /* NULL lower mnt is ok if this is a negative dentry */ + if (!dentry->d_inode && !unionfs_lower_mnt_idx(dentry, bindex)) + continue; + unionfs_mntput(dentry, bindex); + unionfs_set_lower_mnt_idx(dentry, bindex, NULL); + } + /* free private data (unionfs_dentry_info) here */ + kfree(UNIONFS_D(dentry)->lower_paths); + UNIONFS_D(dentry)->lower_paths = NULL; + +out_free: + /* No need to unlock it, because it is disappeared. */ + free_dentry_private_data(dentry); + +out: + unionfs_read_unlock(dentry->d_sb); + return; +} + +struct dentry_operations unionfs_dops = { + .d_revalidate = unionfs_d_revalidate, + .d_release = unionfs_d_release, +}; diff -puN /dev/null fs/unionfs/dirfops.c --- /dev/null +++ a/fs/unionfs/dirfops.c @@ -0,0 +1,290 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* Make sure our rdstate is playing by the rules. */ +static void verify_rdstate_offset(struct unionfs_dir_state *rdstate) +{ + BUG_ON(rdstate->offset >= DIREOF); + BUG_ON(rdstate->cookie >= MAXRDCOOKIE); +} + +struct unionfs_getdents_callback { + struct unionfs_dir_state *rdstate; + void *dirent; + int entries_written; + int filldir_called; + int filldir_error; + filldir_t filldir; + struct super_block *sb; +}; + +/* based on generic filldir in fs/readir.c */ +static int unionfs_filldir(void *dirent, const char *name, int namelen, + loff_t offset, u64 ino, unsigned int d_type) +{ + struct unionfs_getdents_callback *buf = dirent; + struct filldir_node *found = NULL; + int err = 0; + int is_wh_entry = 0; + + buf->filldir_called++; + + if ((namelen > UNIONFS_WHLEN) && + !strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) { + name += UNIONFS_WHLEN; + namelen -= UNIONFS_WHLEN; + is_wh_entry = 1; + } + + found = find_filldir_node(buf->rdstate, name, namelen, is_wh_entry); + + if (found) { + /* + * If we had non-whiteout entry in dir cache, then mark it + * as a whiteout and but leave it in the dir cache. + */ + if (is_wh_entry && !found->whiteout) + found->whiteout = is_wh_entry; + goto out; + } + + /* if 'name' isn't a whiteout, filldir it. */ + if (!is_wh_entry) { + off_t pos = rdstate2offset(buf->rdstate); + u64 unionfs_ino = ino; + + err = buf->filldir(buf->dirent, name, namelen, pos, + unionfs_ino, d_type); + buf->rdstate->offset++; + verify_rdstate_offset(buf->rdstate); + } + /* + * If we did fill it, stuff it in our hash, otherwise return an + * error. + */ + if (err) { + buf->filldir_error = err; + goto out; + } + buf->entries_written++; + err = add_filldir_node(buf->rdstate, name, namelen, + buf->rdstate->bindex, is_wh_entry); + if (err) + buf->filldir_error = err; + +out: + return err; +} + +static int unionfs_readdir(struct file *file, void *dirent, filldir_t filldir) +{ + int err = 0; + struct file *lower_file = NULL; + struct inode *inode = NULL; + struct unionfs_getdents_callback buf; + struct unionfs_dir_state *uds; + int bend; + loff_t offset; + + unionfs_read_lock(file->f_path.dentry->d_sb); + + err = unionfs_file_revalidate(file, false); + if (unlikely(err)) + goto out; + + inode = file->f_path.dentry->d_inode; + + uds = UNIONFS_F(file)->rdstate; + if (!uds) { + if (file->f_pos == DIREOF) { + goto out; + } else if (file->f_pos > 0) { + uds = find_rdstate(inode, file->f_pos); + if (unlikely(!uds)) { + err = -ESTALE; + goto out; + } + UNIONFS_F(file)->rdstate = uds; + } else { + init_rdstate(file); + uds = UNIONFS_F(file)->rdstate; + } + } + bend = fbend(file); + + while (uds->bindex <= bend) { + lower_file = unionfs_lower_file_idx(file, uds->bindex); + if (!lower_file) { + uds->bindex++; + uds->dirpos = 0; + continue; + } + + /* prepare callback buffer */ + buf.filldir_called = 0; + buf.filldir_error = 0; + buf.entries_written = 0; + buf.dirent = dirent; + buf.filldir = filldir; + buf.rdstate = uds; + buf.sb = inode->i_sb; + + /* Read starting from where we last left off. */ + offset = vfs_llseek(lower_file, uds->dirpos, SEEK_SET); + if (offset < 0) { + err = offset; + goto out; + } + err = vfs_readdir(lower_file, unionfs_filldir, &buf); + + /* Save the position for when we continue. */ + offset = vfs_llseek(lower_file, 0, SEEK_CUR); + if (offset < 0) { + err = offset; + goto out; + } + uds->dirpos = offset; + + /* Copy the atime. */ + fsstack_copy_attr_atime(inode, + lower_file->f_path.dentry->d_inode); + + if (err < 0) + goto out; + + if (buf.filldir_error) + break; + + if (!buf.entries_written) { + uds->bindex++; + uds->dirpos = 0; + } + } + + if (!buf.filldir_error && uds->bindex >= bend) { + /* Save the number of hash entries for next time. */ + UNIONFS_I(inode)->hashsize = uds->hashentries; + free_rdstate(uds); + UNIONFS_F(file)->rdstate = NULL; + file->f_pos = DIREOF; + } else { + file->f_pos = rdstate2offset(uds); + } + +out: + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +/* + * This is not meant to be a generic repositioning function. If you do + * things that aren't supported, then we return EINVAL. + * + * What is allowed: + * (1) seeking to the same position that you are currently at + * This really has no effect, but returns where you are. + * (2) seeking to the beginning of the file + * This throws out all state, and lets you begin again. + */ +static loff_t unionfs_dir_llseek(struct file *file, loff_t offset, int origin) +{ + struct unionfs_dir_state *rdstate; + loff_t err; + + unionfs_read_lock(file->f_path.dentry->d_sb); + + err = unionfs_file_revalidate(file, false); + if (unlikely(err)) + goto out; + + rdstate = UNIONFS_F(file)->rdstate; + + /* + * we let users seek to their current position, but not anywhere + * else. + */ + if (!offset) { + switch (origin) { + case SEEK_SET: + if (rdstate) { + free_rdstate(rdstate); + UNIONFS_F(file)->rdstate = NULL; + } + init_rdstate(file); + err = 0; + break; + case SEEK_CUR: + err = file->f_pos; + break; + case SEEK_END: + /* Unsupported, because we would break everything. */ + err = -EINVAL; + break; + } + } else { + switch (origin) { + case SEEK_SET: + if (rdstate) { + if (offset == rdstate2offset(rdstate)) + err = offset; + else if (file->f_pos == DIREOF) + err = DIREOF; + else + err = -EINVAL; + } else { + struct inode *inode; + inode = file->f_path.dentry->d_inode; + rdstate = find_rdstate(inode, offset); + if (rdstate) { + UNIONFS_F(file)->rdstate = rdstate; + err = rdstate->offset; + } else { + err = -EINVAL; + } + } + break; + case SEEK_CUR: + case SEEK_END: + /* Unsupported, because we would break everything. */ + err = -EINVAL; + break; + } + } + +out: + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +/* + * Trimmed directory options, we shouldn't pass everything down since + * we don't want to operate on partial directories. + */ +struct file_operations unionfs_dir_fops = { + .llseek = unionfs_dir_llseek, + .read = generic_read_dir, + .readdir = unionfs_readdir, + .unlocked_ioctl = unionfs_ioctl, + .open = unionfs_open, + .release = unionfs_file_release, + .flush = unionfs_flush, + .fsync = unionfs_fsync, + .fasync = unionfs_fasync, +}; diff -puN /dev/null fs/unionfs/dirhelper.c --- /dev/null +++ a/fs/unionfs/dirhelper.c @@ -0,0 +1,272 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * Delete all of the whiteouts in a given directory for rmdir. + * + * lower directory inode should be locked + */ +int do_delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist) +{ + int err = 0; + struct dentry *lower_dir_dentry = NULL; + struct dentry *lower_dentry; + char *name = NULL, *p; + struct inode *lower_dir; + int i; + struct list_head *pos; + struct filldir_node *cursor; + + /* Find out lower parent dentry */ + lower_dir_dentry = unionfs_lower_dentry_idx(dentry, bindex); + BUG_ON(!S_ISDIR(lower_dir_dentry->d_inode->i_mode)); + lower_dir = lower_dir_dentry->d_inode; + BUG_ON(!S_ISDIR(lower_dir->i_mode)); + + err = -ENOMEM; + name = __getname(); + if (unlikely(!name)) + goto out; + strcpy(name, UNIONFS_WHPFX); + p = name + UNIONFS_WHLEN; + + err = 0; + for (i = 0; !err && i < namelist->size; i++) { + list_for_each(pos, &namelist->list[i]) { + cursor = + list_entry(pos, struct filldir_node, + file_list); + /* Only operate on whiteouts in this branch. */ + if (cursor->bindex != bindex) + continue; + if (!cursor->whiteout) + continue; + + strcpy(p, cursor->name); + lower_dentry = + lookup_one_len(name, lower_dir_dentry, + cursor->namelen + + UNIONFS_WHLEN); + if (IS_ERR(lower_dentry)) { + err = PTR_ERR(lower_dentry); + break; + } + if (lower_dentry->d_inode) + err = vfs_unlink(lower_dir, lower_dentry); + dput(lower_dentry); + if (err) + break; + } + } + + __putname(name); + + /* After all of the removals, we should copy the attributes once. */ + fsstack_copy_attr_times(dentry->d_inode, lower_dir_dentry->d_inode); + +out: + return err; +} + +/* delete whiteouts in a dir (for rmdir operation) using sioq if necessary */ +int delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist) +{ + int err; + struct super_block *sb; + struct dentry *lower_dir_dentry; + struct inode *lower_dir; + struct sioq_args args; + + sb = dentry->d_sb; + + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode)); + BUG_ON(bindex < dbstart(dentry)); + BUG_ON(bindex > dbend(dentry)); + err = is_robranch_super(sb, bindex); + if (err) + goto out; + + lower_dir_dentry = unionfs_lower_dentry_idx(dentry, bindex); + BUG_ON(!S_ISDIR(lower_dir_dentry->d_inode->i_mode)); + lower_dir = lower_dir_dentry->d_inode; + BUG_ON(!S_ISDIR(lower_dir->i_mode)); + + mutex_lock(&lower_dir->i_mutex); + if (!permission(lower_dir, MAY_WRITE | MAY_EXEC, NULL)) { + err = do_delete_whiteouts(dentry, bindex, namelist); + } else { + args.deletewh.namelist = namelist; + args.deletewh.dentry = dentry; + args.deletewh.bindex = bindex; + run_sioq(__delete_whiteouts, &args); + err = args.err; + } + mutex_unlock(&lower_dir->i_mutex); + +out: + return err; +} + +#define RD_NONE 0 +#define RD_CHECK_EMPTY 1 +/* The callback structure for check_empty. */ +struct unionfs_rdutil_callback { + int err; + int filldir_called; + struct unionfs_dir_state *rdstate; + int mode; +}; + +/* This filldir function makes sure only whiteouts exist within a directory. */ +static int readdir_util_callback(void *dirent, const char *name, int namelen, + loff_t offset, u64 ino, unsigned int d_type) +{ + int err = 0; + struct unionfs_rdutil_callback *buf = dirent; + int whiteout = 0; + struct filldir_node *found; + + buf->filldir_called = 1; + + if (name[0] == '.' && (namelen == 1 || + (name[1] == '.' && namelen == 2))) + goto out; + + if (namelen > UNIONFS_WHLEN && + !strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) { + namelen -= UNIONFS_WHLEN; + name += UNIONFS_WHLEN; + whiteout = 1; + } + + found = find_filldir_node(buf->rdstate, name, namelen, whiteout); + /* If it was found in the table there was a previous whiteout. */ + if (found) + goto out; + + /* + * if it wasn't found and isn't a whiteout, the directory isn't + * empty. + */ + err = -ENOTEMPTY; + if ((buf->mode == RD_CHECK_EMPTY) && !whiteout) + goto out; + + err = add_filldir_node(buf->rdstate, name, namelen, + buf->rdstate->bindex, whiteout); + +out: + buf->err = err; + return err; +} + +/* Is a directory logically empty? */ +int check_empty(struct dentry *dentry, struct unionfs_dir_state **namelist) +{ + int err = 0; + struct dentry *lower_dentry = NULL; + struct super_block *sb; + struct file *lower_file; + struct unionfs_rdutil_callback *buf = NULL; + int bindex, bstart, bend, bopaque; + + sb = dentry->d_sb; + + + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode)); + + err = unionfs_partial_lookup(dentry); + if (err) + goto out; + + bstart = dbstart(dentry); + bend = dbend(dentry); + bopaque = dbopaque(dentry); + if (0 <= bopaque && bopaque < bend) + bend = bopaque; + + buf = kmalloc(sizeof(struct unionfs_rdutil_callback), GFP_KERNEL); + if (unlikely(!buf)) { + err = -ENOMEM; + goto out; + } + buf->err = 0; + buf->mode = RD_CHECK_EMPTY; + buf->rdstate = alloc_rdstate(dentry->d_inode, bstart); + if (unlikely(!buf->rdstate)) { + err = -ENOMEM; + goto out; + } + + /* Process the lower directories with rdutil_callback as a filldir. */ + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) + continue; + if (!lower_dentry->d_inode) + continue; + if (!S_ISDIR(lower_dentry->d_inode->i_mode)) + continue; + + dget(lower_dentry); + unionfs_mntget(dentry, bindex); + branchget(sb, bindex); + lower_file = + dentry_open(lower_dentry, + unionfs_lower_mnt_idx(dentry, bindex), + O_RDONLY); + if (IS_ERR(lower_file)) { + err = PTR_ERR(lower_file); + dput(lower_dentry); + branchput(sb, bindex); + goto out; + } + + do { + buf->filldir_called = 0; + buf->rdstate->bindex = bindex; + err = vfs_readdir(lower_file, + readdir_util_callback, buf); + if (buf->err) + err = buf->err; + } while ((err >= 0) && buf->filldir_called); + + /* fput calls dput for lower_dentry */ + fput(lower_file); + branchput(sb, bindex); + + if (err < 0) + goto out; + } + +out: + if (buf) { + if (namelist && !err) + *namelist = buf->rdstate; + else if (buf->rdstate) + free_rdstate(buf->rdstate); + kfree(buf); + } + + + return err; +} diff -puN /dev/null fs/unionfs/fanout.h --- /dev/null +++ a/fs/unionfs/fanout.h @@ -0,0 +1,355 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _FANOUT_H_ +#define _FANOUT_H_ + +/* + * Inode to private data + * + * Since we use containers and the struct inode is _inside_ the + * unionfs_inode_info structure, UNIONFS_I will always (given a non-NULL + * inode pointer), return a valid non-NULL pointer. + */ +static inline struct unionfs_inode_info *UNIONFS_I(const struct inode *inode) +{ + return container_of(inode, struct unionfs_inode_info, vfs_inode); +} + +#define ibstart(ino) (UNIONFS_I(ino)->bstart) +#define ibend(ino) (UNIONFS_I(ino)->bend) + +/* Superblock to private data */ +#define UNIONFS_SB(super) ((struct unionfs_sb_info *)(super)->s_fs_info) +#define sbstart(sb) 0 +#define sbend(sb) (UNIONFS_SB(sb)->bend) +#define sbmax(sb) (UNIONFS_SB(sb)->bend + 1) +#define sbhbid(sb) (UNIONFS_SB(sb)->high_branch_id) + +/* File to private Data */ +#define UNIONFS_F(file) ((struct unionfs_file_info *)((file)->private_data)) +#define fbstart(file) (UNIONFS_F(file)->bstart) +#define fbend(file) (UNIONFS_F(file)->bend) + +/* macros to manipulate branch IDs in stored in our superblock */ +static inline int branch_id(struct super_block *sb, int index) +{ + BUG_ON(!sb || index < 0); + return UNIONFS_SB(sb)->data[index].branch_id; +} + +static inline void set_branch_id(struct super_block *sb, int index, int val) +{ + BUG_ON(!sb || index < 0); + UNIONFS_SB(sb)->data[index].branch_id = val; +} + +static inline void new_branch_id(struct super_block *sb, int index) +{ + BUG_ON(!sb || index < 0); + set_branch_id(sb, index, ++UNIONFS_SB(sb)->high_branch_id); +} + +/* + * Find new index of matching branch with an existing superblock of a known + * (possibly old) id. This is needed because branches could have been + * added/deleted causing the branches of any open files to shift. + * + * @sb: the new superblock which may have new/different branch IDs + * @id: the old/existing id we're looking for + * Returns index of newly found branch (0 or greater), -1 otherwise. + */ +static inline int branch_id_to_idx(struct super_block *sb, int id) +{ + int i; + for (i = 0; i < sbmax(sb); i++) { + if (branch_id(sb, i) == id) + return i; + } + /* in the non-ODF code, this should really never happen */ + printk(KERN_WARNING "unionfs: cannot find branch with id %d\n", id); + return -1; +} + +/* File to lower file. */ +static inline struct file *unionfs_lower_file(const struct file *f) +{ + BUG_ON(!f); + return UNIONFS_F(f)->lower_files[fbstart(f)]; +} + +static inline struct file *unionfs_lower_file_idx(const struct file *f, + int index) +{ + BUG_ON(!f || index < 0); + return UNIONFS_F(f)->lower_files[index]; +} + +static inline void unionfs_set_lower_file_idx(struct file *f, int index, + struct file *val) +{ + BUG_ON(!f || index < 0); + UNIONFS_F(f)->lower_files[index] = val; + /* save branch ID (may be redundant?) */ + UNIONFS_F(f)->saved_branch_ids[index] = + branch_id((f)->f_path.dentry->d_sb, index); +} + +static inline void unionfs_set_lower_file(struct file *f, struct file *val) +{ + BUG_ON(!f); + unionfs_set_lower_file_idx((f), fbstart(f), (val)); +} + +/* Inode to lower inode. */ +static inline struct inode *unionfs_lower_inode(const struct inode *i) +{ + BUG_ON(!i); + return UNIONFS_I(i)->lower_inodes[ibstart(i)]; +} + +static inline struct inode *unionfs_lower_inode_idx(const struct inode *i, + int index) +{ + BUG_ON(!i || index < 0); + return UNIONFS_I(i)->lower_inodes[index]; +} + +static inline void unionfs_set_lower_inode_idx(struct inode *i, int index, + struct inode *val) +{ + BUG_ON(!i || index < 0); + UNIONFS_I(i)->lower_inodes[index] = val; +} + +static inline void unionfs_set_lower_inode(struct inode *i, struct inode *val) +{ + BUG_ON(!i); + UNIONFS_I(i)->lower_inodes[ibstart(i)] = val; +} + +/* Superblock to lower superblock. */ +static inline struct super_block *unionfs_lower_super( + const struct super_block *sb) +{ + BUG_ON(!sb); + return UNIONFS_SB(sb)->data[sbstart(sb)].sb; +} + +static inline struct super_block *unionfs_lower_super_idx( + const struct super_block *sb, + int index) +{ + BUG_ON(!sb || index < 0); + return UNIONFS_SB(sb)->data[index].sb; +} + +static inline void unionfs_set_lower_super_idx(struct super_block *sb, + int index, + struct super_block *val) +{ + BUG_ON(!sb || index < 0); + UNIONFS_SB(sb)->data[index].sb = val; +} + +static inline void unionfs_set_lower_super(struct super_block *sb, + struct super_block *val) +{ + BUG_ON(!sb); + UNIONFS_SB(sb)->data[sbstart(sb)].sb = val; +} + +/* Branch count macros. */ +static inline int branch_count(const struct super_block *sb, int index) +{ + BUG_ON(!sb || index < 0); + return atomic_read(&UNIONFS_SB(sb)->data[index].open_files); +} + +static inline void set_branch_count(struct super_block *sb, int index, int val) +{ + BUG_ON(!sb || index < 0); + atomic_set(&UNIONFS_SB(sb)->data[index].open_files, val); +} + +static inline void branchget(struct super_block *sb, int index) +{ + BUG_ON(!sb || index < 0); + atomic_inc(&UNIONFS_SB(sb)->data[index].open_files); +} + +static inline void branchput(struct super_block *sb, int index) +{ + BUG_ON(!sb || index < 0); + atomic_dec(&UNIONFS_SB(sb)->data[index].open_files); +} + +/* Dentry macros */ +static inline struct unionfs_dentry_info *UNIONFS_D(const struct dentry *dent) +{ + BUG_ON(!dent); + return dent->d_fsdata; +} + +static inline int dbstart(const struct dentry *dent) +{ + BUG_ON(!dent); + return UNIONFS_D(dent)->bstart; +} + +static inline void set_dbstart(struct dentry *dent, int val) +{ + BUG_ON(!dent); + UNIONFS_D(dent)->bstart = val; +} + +static inline int dbend(const struct dentry *dent) +{ + BUG_ON(!dent); + return UNIONFS_D(dent)->bend; +} + +static inline void set_dbend(struct dentry *dent, int val) +{ + BUG_ON(!dent); + UNIONFS_D(dent)->bend = val; +} + +static inline int dbopaque(const struct dentry *dent) +{ + BUG_ON(!dent); + return UNIONFS_D(dent)->bopaque; +} + +static inline void set_dbopaque(struct dentry *dent, int val) +{ + BUG_ON(!dent); + UNIONFS_D(dent)->bopaque = val; +} + +static inline void unionfs_set_lower_dentry_idx(struct dentry *dent, int index, + struct dentry *val) +{ + BUG_ON(!dent || index < 0); + UNIONFS_D(dent)->lower_paths[index].dentry = val; +} + +static inline struct dentry *unionfs_lower_dentry_idx( + const struct dentry *dent, + int index) +{ + BUG_ON(!dent || index < 0); + return UNIONFS_D(dent)->lower_paths[index].dentry; +} + +static inline struct dentry *unionfs_lower_dentry(const struct dentry *dent) +{ + BUG_ON(!dent); + return unionfs_lower_dentry_idx(dent, dbstart(dent)); +} + +static inline void unionfs_set_lower_mnt_idx(struct dentry *dent, int index, + struct vfsmount *mnt) +{ + BUG_ON(!dent || index < 0); + UNIONFS_D(dent)->lower_paths[index].mnt = mnt; +} + +static inline struct vfsmount *unionfs_lower_mnt_idx( + const struct dentry *dent, + int index) +{ + BUG_ON(!dent || index < 0); + return UNIONFS_D(dent)->lower_paths[index].mnt; +} + +static inline struct vfsmount *unionfs_lower_mnt(const struct dentry *dent) +{ + BUG_ON(!dent); + return unionfs_lower_mnt_idx(dent, dbstart(dent)); +} + +/* Macros for locking a dentry. */ +static inline void unionfs_lock_dentry(struct dentry *d) +{ + BUG_ON(!d); + mutex_lock(&UNIONFS_D(d)->lock); +} + +static inline void unionfs_unlock_dentry(struct dentry *d) +{ + BUG_ON(!d); + mutex_unlock(&UNIONFS_D(d)->lock); +} + +static inline void verify_locked(struct dentry *d) +{ + BUG_ON(!d); + BUG_ON(!mutex_is_locked(&UNIONFS_D(d)->lock)); +} + +/* copy a/m/ctime from the lower branch with the newest times */ +static inline void unionfs_copy_attr_times(struct inode *upper) +{ + int bindex; + struct inode *lower; + + if (!upper || ibstart(upper) < 0) + return; + for (bindex = ibstart(upper); bindex <= ibend(upper); bindex++) { + lower = unionfs_lower_inode_idx(upper, bindex); + if (!lower) + continue; /* not all lower dir objects may exist */ + if (unlikely(timespec_compare(&upper->i_mtime, + &lower->i_mtime) < 0)) + upper->i_mtime = lower->i_mtime; + if (unlikely(timespec_compare(&upper->i_ctime, + &lower->i_ctime) < 0)) + upper->i_ctime = lower->i_ctime; + if (unlikely(timespec_compare(&upper->i_atime, + &lower->i_atime) < 0)) + upper->i_atime = lower->i_atime; + } +} + +/* + * A unionfs/fanout version of fsstack_copy_attr_all. Uses a + * unionfs_get_nlinks to properly calcluate the number of links to a file. + * Also, copies the max() of all a/m/ctimes for all lower inodes (which is + * important if the lower inode is a directory type) + */ +static inline void unionfs_copy_attr_all(struct inode *dest, + const struct inode *src) +{ + dest->i_mode = src->i_mode; + dest->i_uid = src->i_uid; + dest->i_gid = src->i_gid; + dest->i_rdev = src->i_rdev; + + unionfs_copy_attr_times(dest); + + dest->i_blkbits = src->i_blkbits; + dest->i_flags = src->i_flags; + + /* + * Update the nlinks AFTER updating the above fields, because the + * get_links callback may depend on them. + */ + dest->i_nlink = unionfs_get_nlinks(dest); +} + +#endif /* not _FANOUT_H */ diff -puN /dev/null fs/unionfs/file.c --- /dev/null +++ a/fs/unionfs/file.c @@ -0,0 +1,227 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +static ssize_t unionfs_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + int err; + + unionfs_read_lock(file->f_path.dentry->d_sb); + err = unionfs_file_revalidate(file, false); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + err = do_sync_read(file, buf, count, ppos); + +out: + unionfs_check_file(file); + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +static ssize_t unionfs_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + int err = 0; + + unionfs_read_lock(file->f_path.dentry->d_sb); + err = unionfs_file_revalidate(file, true); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + err = do_sync_write(file, buf, count, ppos); + /* update our inode times upon a successful lower write */ + if (err >= 0) { + unionfs_copy_attr_times(file->f_path.dentry->d_inode); + unionfs_check_file(file); + } + +out: + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +static int unionfs_file_readdir(struct file *file, void *dirent, + filldir_t filldir) +{ + return -ENOTDIR; +} + +static int unionfs_mmap(struct file *file, struct vm_area_struct *vma) +{ + int err = 0; + bool willwrite; + struct file *lower_file; + + unionfs_read_lock(file->f_path.dentry->d_sb); + + /* This might be deferred to mmap's writepage */ + willwrite = ((vma->vm_flags | VM_SHARED | VM_WRITE) == vma->vm_flags); + err = unionfs_file_revalidate(file, willwrite); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + /* + * File systems which do not implement ->writepage may use + * generic_file_readonly_mmap as their ->mmap op. If you call + * generic_file_readonly_mmap with VM_WRITE, you'd get an -EINVAL. + * But we cannot call the lower ->mmap op, so we can't tell that + * writeable mappings won't work. Therefore, our only choice is to + * check if the lower file system supports the ->writepage, and if + * not, return EINVAL (the same error that + * generic_file_readonly_mmap returns in that case). + */ + lower_file = unionfs_lower_file(file); + if (willwrite && !lower_file->f_mapping->a_ops->writepage) { + err = -EINVAL; + printk(KERN_ERR "unionfs: branch %d file system does not " + "support writeable mmap\n", fbstart(file)); + } else { + err = generic_file_mmap(file, vma); + if (err) + printk(KERN_ERR + "unionfs: generic_file_mmap failed %d\n", err); + } + +out: + if (!err) { + /* copyup could cause parent dir times to change */ + unionfs_copy_attr_times(file->f_path.dentry->d_parent->d_inode); + unionfs_check_file(file); + unionfs_check_dentry(file->f_path.dentry->d_parent); + } + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +int unionfs_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + int bindex, bstart, bend; + struct file *lower_file; + struct dentry *lower_dentry; + struct inode *lower_inode, *inode; + int err = -EINVAL; + + unionfs_read_lock(file->f_path.dentry->d_sb); + err = unionfs_file_revalidate(file, true); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + bstart = fbstart(file); + bend = fbend(file); + if (bstart < 0 || bend < 0) + goto out; + + inode = dentry->d_inode; + if (unlikely(!inode)) { + printk(KERN_ERR + "unionfs: null lower inode in unionfs_fsync\n"); + goto out; + } + for (bindex = bstart; bindex <= bend; bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (!lower_inode || !lower_inode->i_fop->fsync) + continue; + lower_file = unionfs_lower_file_idx(file, bindex); + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + mutex_lock(&lower_inode->i_mutex); + err = lower_inode->i_fop->fsync(lower_file, + lower_dentry, + datasync); + mutex_unlock(&lower_inode->i_mutex); + if (err) + goto out; + } + + unionfs_copy_attr_times(inode); + +out: + unionfs_check_file(file); + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +int unionfs_fasync(int fd, struct file *file, int flag) +{ + int bindex, bstart, bend; + struct file *lower_file; + struct dentry *dentry; + struct inode *lower_inode, *inode; + int err = 0; + + unionfs_read_lock(file->f_path.dentry->d_sb); + err = unionfs_file_revalidate(file, true); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + bstart = fbstart(file); + bend = fbend(file); + if (bstart < 0 || bend < 0) + goto out; + + dentry = file->f_path.dentry; + inode = dentry->d_inode; + if (unlikely(!inode)) { + printk(KERN_ERR + "unionfs: null lower inode in unionfs_fasync\n"); + goto out; + } + for (bindex = bstart; bindex <= bend; bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (!lower_inode || !lower_inode->i_fop->fasync) + continue; + lower_file = unionfs_lower_file_idx(file, bindex); + mutex_lock(&lower_inode->i_mutex); + err = lower_inode->i_fop->fasync(fd, lower_file, flag); + mutex_unlock(&lower_inode->i_mutex); + if (err) + goto out; + } + + unionfs_copy_attr_times(inode); + +out: + unionfs_check_file(file); + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; +} + +struct file_operations unionfs_main_fops = { + .llseek = generic_file_llseek, + .read = unionfs_read, + .aio_read = generic_file_aio_read, + .write = unionfs_write, + .aio_write = generic_file_aio_write, + .readdir = unionfs_file_readdir, + .unlocked_ioctl = unionfs_ioctl, + .mmap = unionfs_mmap, + .open = unionfs_open, + .flush = unionfs_flush, + .release = unionfs_file_release, + .fsync = unionfs_fsync, + .fasync = unionfs_fasync, + .splice_read = generic_file_splice_read, + .splice_write = generic_file_splice_write, +}; diff -puN /dev/null fs/unionfs/inode.c --- /dev/null +++ a/fs/unionfs/inode.c @@ -0,0 +1,1154 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +static int unionfs_create(struct inode *parent, struct dentry *dentry, + int mode, struct nameidata *nd) +{ + int err = 0; + struct dentry *lower_dentry = NULL; + struct dentry *wh_dentry = NULL; + struct dentry *lower_parent_dentry = NULL; + char *name = NULL; + int valid = 0; + struct nameidata lower_nd; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + unionfs_lock_dentry(dentry->d_parent); + valid = __unionfs_d_revalidate_chain(dentry->d_parent, nd, false); + unionfs_unlock_dentry(dentry->d_parent); + if (unlikely(!valid)) { + err = -ESTALE; /* same as what real_lookup does */ + goto out; + } + valid = __unionfs_d_revalidate_chain(dentry, nd, false); + /* + * It's only a bug if this dentry was not negative and couldn't be + * revalidated (shouldn't happen). + */ + BUG_ON(!valid && dentry->d_inode); + + /* + * We shouldn't create things in a read-only branch; this check is a + * bit redundant as we don't allow branch 0 to be read-only at the + * moment + */ + err = is_robranch_super(dentry->d_sb, 0); + if (err) { + err = -EROFS; + goto out; + } + + /* + * We _always_ create on branch 0 + */ + lower_dentry = unionfs_lower_dentry_idx(dentry, 0); + if (lower_dentry) { + /* + * check if whiteout exists in this branch, i.e. lookup .wh.foo + * first. + */ + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); + if (unlikely(IS_ERR(name))) { + err = PTR_ERR(name); + goto out; + } + + wh_dentry = lookup_one_len(name, lower_dentry->d_parent, + dentry->d_name.len + UNIONFS_WHLEN); + if (IS_ERR(wh_dentry)) { + err = PTR_ERR(wh_dentry); + wh_dentry = NULL; + goto out; + } + + if (wh_dentry->d_inode) { + /* + * .wh.foo has been found, so let's unlink it + */ + struct dentry *lower_dir_dentry; + + lower_dir_dentry = lock_parent(wh_dentry); + err = vfs_unlink(lower_dir_dentry->d_inode, wh_dentry); + unlock_dir(lower_dir_dentry); + + /* + * Whiteouts are special files and should be deleted + * no matter what (as if they never existed), in + * order to allow this create operation to succeed. + * This is especially important in sticky + * directories: a whiteout may have been created by + * one user, but the newly created file may be + * created by another user. Therefore, in order to + * maintain Unix semantics, if the vfs_unlink above + * ailed, then we have to try to directly unlink the + * whiteout. Note: in the ODF version of unionfs, + * whiteout are handled much more cleanly. + */ + if (err == -EPERM) { + struct inode *inode = lower_dir_dentry->d_inode; + err = inode->i_op->unlink(inode, wh_dentry); + } + if (err) { + printk(KERN_ERR "unionfs: create: could not " + "unlink whiteout, err = %d\n", err); + goto out; + } + } + } else { + /* + * if lower_dentry is NULL, create the entire + * dentry directory structure in branch 0. + */ + lower_dentry = create_parents(parent, dentry, + dentry->d_name.name, 0); + if (IS_ERR(lower_dentry)) { + err = PTR_ERR(lower_dentry); + goto out; + } + } + + lower_parent_dentry = lock_parent(lower_dentry); + if (IS_ERR(lower_parent_dentry)) { + err = PTR_ERR(lower_parent_dentry); + goto out; + } + + err = init_lower_nd(&lower_nd, LOOKUP_CREATE); + if (unlikely(err < 0)) + goto out; + err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, + &lower_nd); + release_lower_nd(&lower_nd, err); + + if (!err) { + err = PTR_ERR(unionfs_interpose(dentry, parent->i_sb, 0)); + if (!err) { + unionfs_copy_attr_times(parent); + fsstack_copy_inode_size(parent, + lower_parent_dentry->d_inode); + /* update no. of links on parent directory */ + parent->i_nlink = unionfs_get_nlinks(parent); + } + } + + unlock_dir(lower_parent_dentry); + +out: + dput(wh_dentry); + kfree(name); + + if (!err) + unionfs_postcopyup_setmnt(dentry); + + unionfs_check_inode(parent); + if (!err) { + unionfs_check_dentry(dentry->d_parent); + unionfs_check_nd(nd); + } + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + return err; +} + +/* + * unionfs_lookup is the only special function which takes a dentry, yet we + * do NOT want to call __unionfs_d_revalidate_chain because by definition, + * we don't have a valid dentry here yet. + */ +static struct dentry *unionfs_lookup(struct inode *parent, + struct dentry *dentry, + struct nameidata *nd) +{ + struct path path_save; + struct dentry *ret; + + unionfs_read_lock(dentry->d_sb); + + /* save the dentry & vfsmnt from namei */ + if (nd) { + path_save.dentry = nd->dentry; + path_save.mnt = nd->mnt; + } + + /* + * unionfs_lookup_backend returns a locked dentry upon success, + * so we'll have to unlock it below. + */ + ret = unionfs_lookup_backend(dentry, nd, INTERPOSE_LOOKUP); + + /* restore the dentry & vfsmnt in namei */ + if (nd) { + nd->dentry = path_save.dentry; + nd->mnt = path_save.mnt; + } + if (!IS_ERR(ret)) { + if (ret) + dentry = ret; + /* parent times may have changed */ + unionfs_copy_attr_times(dentry->d_parent->d_inode); + } + + unionfs_check_inode(parent); + unionfs_check_dentry(dentry); + unionfs_check_dentry(dentry->d_parent); + unionfs_check_nd(nd); + if (!IS_ERR(ret)) + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + + return ret; +} + +static int unionfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + int err = 0; + struct dentry *lower_old_dentry = NULL; + struct dentry *lower_new_dentry = NULL; + struct dentry *lower_dir_dentry = NULL; + struct dentry *whiteout_dentry; + char *name = NULL; + + unionfs_read_lock(old_dentry->d_sb); + unionfs_double_lock_dentry(new_dentry, old_dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(old_dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + if (unlikely(new_dentry->d_inode && + !__unionfs_d_revalidate_chain(new_dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + lower_new_dentry = unionfs_lower_dentry(new_dentry); + + /* + * check if whiteout exists in the branch of new dentry, i.e. lookup + * .wh.foo first. If present, delete it + */ + name = alloc_whname(new_dentry->d_name.name, new_dentry->d_name.len); + if (unlikely(IS_ERR(name))) { + err = PTR_ERR(name); + goto out; + } + + whiteout_dentry = lookup_one_len(name, lower_new_dentry->d_parent, + new_dentry->d_name.len + + UNIONFS_WHLEN); + if (IS_ERR(whiteout_dentry)) { + err = PTR_ERR(whiteout_dentry); + goto out; + } + + if (!whiteout_dentry->d_inode) { + dput(whiteout_dentry); + whiteout_dentry = NULL; + } else { + /* found a .wh.foo entry, unlink it and then call vfs_link() */ + lower_dir_dentry = lock_parent(whiteout_dentry); + err = is_robranch_super(new_dentry->d_sb, dbstart(new_dentry)); + if (!err) + err = vfs_unlink(lower_dir_dentry->d_inode, + whiteout_dentry); + + fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); + dir->i_nlink = unionfs_get_nlinks(dir); + unlock_dir(lower_dir_dentry); + lower_dir_dentry = NULL; + dput(whiteout_dentry); + if (err) + goto out; + } + + if (dbstart(old_dentry) != dbstart(new_dentry)) { + lower_new_dentry = create_parents(dir, new_dentry, + new_dentry->d_name.name, + dbstart(old_dentry)); + err = PTR_ERR(lower_new_dentry); + if (IS_COPYUP_ERR(err)) + goto docopyup; + if (!lower_new_dentry || IS_ERR(lower_new_dentry)) + goto out; + } + lower_new_dentry = unionfs_lower_dentry(new_dentry); + lower_old_dentry = unionfs_lower_dentry(old_dentry); + + BUG_ON(dbstart(old_dentry) != dbstart(new_dentry)); + lower_dir_dentry = lock_parent(lower_new_dentry); + err = is_robranch(old_dentry); + if (!err) + err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode, + lower_new_dentry); + unlock_dir(lower_dir_dentry); + +docopyup: + if (IS_COPYUP_ERR(err)) { + int old_bstart = dbstart(old_dentry); + int bindex; + + for (bindex = old_bstart - 1; bindex >= 0; bindex--) { + err = copyup_dentry(old_dentry->d_parent->d_inode, + old_dentry, old_bstart, + bindex, old_dentry->d_name.name, + old_dentry->d_name.len, NULL, + i_size_read(old_dentry->d_inode)); + if (!err) { + lower_new_dentry = + create_parents(dir, new_dentry, + new_dentry->d_name.name, + bindex); + lower_old_dentry = + unionfs_lower_dentry(old_dentry); + lower_dir_dentry = + lock_parent(lower_new_dentry); + /* do vfs_link */ + err = vfs_link(lower_old_dentry, + lower_dir_dentry->d_inode, + lower_new_dentry); + unlock_dir(lower_dir_dentry); + goto check_link; + } + } + goto out; + } + +check_link: + if (err || !lower_new_dentry->d_inode) + goto out; + + /* Its a hard link, so use the same inode */ + new_dentry->d_inode = igrab(old_dentry->d_inode); + d_instantiate(new_dentry, new_dentry->d_inode); + unionfs_copy_attr_all(dir, lower_new_dentry->d_parent->d_inode); + fsstack_copy_inode_size(dir, lower_new_dentry->d_parent->d_inode); + + /* propagate number of hard-links */ + old_dentry->d_inode->i_nlink = unionfs_get_nlinks(old_dentry->d_inode); + /* new dentry's ctime may have changed due to hard-link counts */ + unionfs_copy_attr_times(new_dentry->d_inode); + +out: + if (!new_dentry->d_inode) + d_drop(new_dentry); + + kfree(name); + if (!err) + unionfs_postcopyup_setmnt(new_dentry); + + unionfs_check_inode(dir); + unionfs_check_dentry(new_dentry); + unionfs_check_dentry(old_dentry); + + unionfs_unlock_dentry(new_dentry); + unionfs_unlock_dentry(old_dentry); + unionfs_read_unlock(old_dentry->d_sb); + + return err; +} + +static int unionfs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + int err = 0; + struct dentry *lower_dentry = NULL; + struct dentry *whiteout_dentry = NULL; + struct dentry *lower_dir_dentry = NULL; + umode_t mode; + int bindex = 0, bstart; + char *name = NULL; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(dentry->d_inode && + !__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + /* We start out in the leftmost branch. */ + bstart = dbstart(dentry); + + lower_dentry = unionfs_lower_dentry(dentry); + + /* + * check if whiteout exists in this branch, i.e. lookup .wh.foo + * first. If present, delete it + */ + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); + if (unlikely(IS_ERR(name))) { + err = PTR_ERR(name); + goto out; + } + + whiteout_dentry = + lookup_one_len(name, lower_dentry->d_parent, + dentry->d_name.len + UNIONFS_WHLEN); + if (IS_ERR(whiteout_dentry)) { + err = PTR_ERR(whiteout_dentry); + goto out; + } + + if (!whiteout_dentry->d_inode) { + dput(whiteout_dentry); + whiteout_dentry = NULL; + } else { + /* + * found a .wh.foo entry, unlink it and then call + * vfs_symlink(). + */ + lower_dir_dentry = lock_parent(whiteout_dentry); + + err = is_robranch_super(dentry->d_sb, bstart); + if (!err) + err = vfs_unlink(lower_dir_dentry->d_inode, + whiteout_dentry); + dput(whiteout_dentry); + + fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); + /* propagate number of hard-links */ + dir->i_nlink = unionfs_get_nlinks(dir); + + unlock_dir(lower_dir_dentry); + + if (err) { + /* exit if the error returned was NOT -EROFS */ + if (!IS_COPYUP_ERR(err)) + goto out; + /* + * should now try to create symlink in the another + * branch. + */ + bstart--; + } + } + + /* + * deleted whiteout if it was present, now do a normal vfs_symlink() + * with possible recursive directory creation + */ + for (bindex = bstart; bindex >= 0; bindex--) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) { + /* + * if lower_dentry is NULL, create the entire + * dentry directory structure in branch 'bindex'. + * lower_dentry will NOT be null when bindex == + * bstart because lookup passed as a negative + * unionfs dentry pointing to a lone negative + * underlying dentry + */ + lower_dentry = create_parents(dir, dentry, + dentry->d_name.name, + bindex); + if (!lower_dentry || IS_ERR(lower_dentry)) { + if (IS_ERR(lower_dentry)) + err = PTR_ERR(lower_dentry); + if (!IS_COPYUP_ERR(err)) + printk(KERN_ERR + "unionfs: create_parents for " + "symlink failed: bindex=%d " + "err=%d\n", bindex, err); + continue; + } + } + + lower_dir_dentry = lock_parent(lower_dentry); + + err = is_robranch_super(dentry->d_sb, bindex); + if (!err) { + mode = S_IALLUGO; + err = vfs_symlink(lower_dir_dentry->d_inode, + lower_dentry, symname, mode); + } + unlock_dir(lower_dir_dentry); + + if (err || !lower_dentry->d_inode) { + /* + * break out of for loop if error returned was NOT + * -EROFS. + */ + if (!IS_COPYUP_ERR(err)) + break; + } else { + /* + * Only INTERPOSE_LOOKUP can return a value other + * than 0 on err. + */ + err = PTR_ERR(unionfs_interpose(dentry, + dir->i_sb, 0)); + if (!err) { + fsstack_copy_attr_times(dir, + lower_dir_dentry-> + d_inode); + fsstack_copy_inode_size(dir, + lower_dir_dentry-> + d_inode); + /* + * update number of links on parent + * directory. + */ + dir->i_nlink = unionfs_get_nlinks(dir); + } + break; + } + } + +out: + if (!dentry->d_inode) + d_drop(dentry); + + kfree(name); + if (!err) + unionfs_postcopyup_setmnt(dentry); + + unionfs_check_inode(dir); + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + + return err; +} + +static int unionfs_mkdir(struct inode *parent, struct dentry *dentry, int mode) +{ + int err = 0; + struct dentry *lower_dentry = NULL, *whiteout_dentry = NULL; + struct dentry *lower_parent_dentry = NULL; + int bindex = 0, bstart; + char *name = NULL; + int whiteout_unlinked = 0; + struct sioq_args args; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(dentry->d_inode && + !__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + bstart = dbstart(dentry); + + lower_dentry = unionfs_lower_dentry(dentry); + + /* + * check if whiteout exists in this branch, i.e. lookup .wh.foo + * first. + */ + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); + if (unlikely(IS_ERR(name))) { + err = PTR_ERR(name); + goto out; + } + + whiteout_dentry = lookup_one_len(name, lower_dentry->d_parent, + dentry->d_name.len + UNIONFS_WHLEN); + if (IS_ERR(whiteout_dentry)) { + err = PTR_ERR(whiteout_dentry); + goto out; + } + + if (!whiteout_dentry->d_inode) { + dput(whiteout_dentry); + whiteout_dentry = NULL; + } else { + lower_parent_dentry = lock_parent(whiteout_dentry); + + /* found a.wh.foo entry, remove it then do vfs_mkdir */ + err = is_robranch_super(dentry->d_sb, bstart); + if (!err) { + args.unlink.parent = lower_parent_dentry->d_inode; + args.unlink.dentry = whiteout_dentry; + run_sioq(__unionfs_unlink, &args); + err = args.err; + } + dput(whiteout_dentry); + + unlock_dir(lower_parent_dentry); + + if (err) { + /* exit if the error returned was NOT -EROFS */ + if (!IS_COPYUP_ERR(err)) + goto out; + bstart--; + } else { + whiteout_unlinked = 1; + } + } + + for (bindex = bstart; bindex >= 0; bindex--) { + int i; + int bend = dbend(dentry); + + if (is_robranch_super(dentry->d_sb, bindex)) + continue; + + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) { + lower_dentry = create_parents(parent, dentry, + dentry->d_name.name, + bindex); + if (!lower_dentry || IS_ERR(lower_dentry)) { + printk(KERN_ERR "unionfs: lower dentry " + " NULL for bindex = %d\n", bindex); + continue; + } + } + + lower_parent_dentry = lock_parent(lower_dentry); + + if (IS_ERR(lower_parent_dentry)) { + err = PTR_ERR(lower_parent_dentry); + goto out; + } + + err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, + mode); + + unlock_dir(lower_parent_dentry); + + /* did the mkdir succeed? */ + if (err) + break; + + for (i = bindex + 1; i < bend; i++) { + if (unionfs_lower_dentry_idx(dentry, i)) { + dput(unionfs_lower_dentry_idx(dentry, i)); + unionfs_set_lower_dentry_idx(dentry, i, NULL); + } + } + set_dbend(dentry, bindex); + + /* + * Only INTERPOSE_LOOKUP can return a value other than 0 on + * err. + */ + err = PTR_ERR(unionfs_interpose(dentry, parent->i_sb, 0)); + if (!err) { + unionfs_copy_attr_times(parent); + fsstack_copy_inode_size(parent, + lower_parent_dentry->d_inode); + + /* update number of links on parent directory */ + parent->i_nlink = unionfs_get_nlinks(parent); + } + + err = make_dir_opaque(dentry, dbstart(dentry)); + if (err) { + printk(KERN_ERR "unionfs: mkdir: error creating " + ".wh.__dir_opaque: %d\n", err); + goto out; + } + + /* we are done! */ + break; + } + +out: + if (!dentry->d_inode) + d_drop(dentry); + + kfree(name); + + if (!err) { + unionfs_copy_attr_times(dentry->d_inode); + unionfs_postcopyup_setmnt(dentry); + } + unionfs_check_inode(parent); + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + + return err; +} + +static int unionfs_mknod(struct inode *dir, struct dentry *dentry, int mode, + dev_t dev) +{ + int err = 0; + struct dentry *lower_dentry = NULL, *whiteout_dentry = NULL; + struct dentry *lower_parent_dentry = NULL; + int bindex = 0, bstart; + char *name = NULL; + int whiteout_unlinked = 0; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(dentry->d_inode && + !__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + bstart = dbstart(dentry); + + lower_dentry = unionfs_lower_dentry(dentry); + + /* + * check if whiteout exists in this branch, i.e. lookup .wh.foo + * first. + */ + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); + if (unlikely(IS_ERR(name))) { + err = PTR_ERR(name); + goto out; + } + + whiteout_dentry = lookup_one_len(name, lower_dentry->d_parent, + dentry->d_name.len + UNIONFS_WHLEN); + if (IS_ERR(whiteout_dentry)) { + err = PTR_ERR(whiteout_dentry); + goto out; + } + + if (!whiteout_dentry->d_inode) { + dput(whiteout_dentry); + whiteout_dentry = NULL; + } else { + /* found .wh.foo, unlink it */ + lower_parent_dentry = lock_parent(whiteout_dentry); + + /* found a.wh.foo entry, remove it then do vfs_mkdir */ + err = is_robranch_super(dentry->d_sb, bstart); + if (!err) + err = vfs_unlink(lower_parent_dentry->d_inode, + whiteout_dentry); + dput(whiteout_dentry); + + unlock_dir(lower_parent_dentry); + + if (err) { + if (!IS_COPYUP_ERR(err)) + goto out; + bstart--; + } else { + whiteout_unlinked = 1; + } + } + + for (bindex = bstart; bindex >= 0; bindex--) { + if (is_robranch_super(dentry->d_sb, bindex)) + continue; + + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) { + lower_dentry = create_parents(dir, dentry, + dentry->d_name.name, + bindex); + if (IS_ERR(lower_dentry)) { + printk(KERN_ERR "unionfs: failed to create " + "parents on %d, err = %ld\n", + bindex, PTR_ERR(lower_dentry)); + continue; + } + } + + lower_parent_dentry = lock_parent(lower_dentry); + if (IS_ERR(lower_parent_dentry)) { + err = PTR_ERR(lower_parent_dentry); + goto out; + } + + err = vfs_mknod(lower_parent_dentry->d_inode, + lower_dentry, mode, dev); + + if (err) { + unlock_dir(lower_parent_dentry); + break; + } + + /* + * Only INTERPOSE_LOOKUP can return a value other than 0 on + * err. + */ + err = PTR_ERR(unionfs_interpose(dentry, dir->i_sb, 0)); + if (!err) { + fsstack_copy_attr_times(dir, + lower_parent_dentry->d_inode); + fsstack_copy_inode_size(dir, + lower_parent_dentry->d_inode); + /* update number of links on parent directory */ + dir->i_nlink = unionfs_get_nlinks(dir); + } + unlock_dir(lower_parent_dentry); + + break; + } + +out: + if (!dentry->d_inode) + d_drop(dentry); + + kfree(name); + + if (!err) + unionfs_postcopyup_setmnt(dentry); + + unionfs_check_inode(dir); + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + + return err; +} + +static int unionfs_readlink(struct dentry *dentry, char __user *buf, + int bufsiz) +{ + int err; + struct dentry *lower_dentry; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + lower_dentry = unionfs_lower_dentry(dentry); + + if (!lower_dentry->d_inode->i_op || + !lower_dentry->d_inode->i_op->readlink) { + err = -EINVAL; + goto out; + } + + err = lower_dentry->d_inode->i_op->readlink(lower_dentry, + buf, bufsiz); + if (err > 0) + fsstack_copy_attr_atime(dentry->d_inode, + lower_dentry->d_inode); + +out: + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + + return err; +} + +/* + * unionfs_follow_link takes a dentry, but it is simple. It only needs to + * allocate some memory and then call our ->readlink method. Our + * unionfs_readlink *does* lock our dentry and revalidate the dentry. + * Therefore, we do not have to lock our dentry here, to prevent a deadlock; + * nor do we need to revalidate it either. It is safe to not lock our + * dentry here, nor revalidate it, because unionfs_follow_link does not do + * anything (prior to calling ->readlink) which could become inconsistent + * due to branch management. + */ +static void *unionfs_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + char *buf; + int len = PAGE_SIZE, err; + mm_segment_t old_fs; + + unionfs_read_lock(dentry->d_sb); + + /* This is freed by the put_link method assuming a successful call. */ + buf = kmalloc(len, GFP_KERNEL); + if (unlikely(!buf)) { + err = -ENOMEM; + goto out; + } + + /* read the symlink, and then we will follow it */ + old_fs = get_fs(); + set_fs(KERNEL_DS); + err = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len); + set_fs(old_fs); + if (err < 0) { + kfree(buf); + buf = NULL; + goto out; + } + buf[err] = 0; + nd_set_link(nd, buf); + err = 0; + +out: + unionfs_check_dentry(dentry); + unionfs_check_nd(nd); + unionfs_read_unlock(dentry->d_sb); + return ERR_PTR(err); +} + +/* FIXME: We may not have to lock here */ +static void unionfs_put_link(struct dentry *dentry, struct nameidata *nd, + void *cookie) +{ + unionfs_read_lock(dentry->d_sb); + + unionfs_lock_dentry(dentry); + if (unlikely(!__unionfs_d_revalidate_chain(dentry, nd, false))) + printk(KERN_ERR + "unionfs: put_link failed to revalidate dentry\n"); + + unionfs_check_dentry(dentry); + unionfs_check_nd(nd); + kfree(nd_get_link(nd)); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); +} + +/* + * Don't grab the superblock read-lock in unionfs_permission, which prevents + * a deadlock with the branch-management "add branch" code (which grabbed + * the write lock). It is safe to not grab the read lock here, because even + * with branch management taking place, there is no chance that + * unionfs_permission, or anything it calls, will use stale branch + * information. + */ +static int unionfs_permission(struct inode *inode, int mask, + struct nameidata *nd) +{ + struct inode *lower_inode = NULL; + int err = 0; + int bindex, bstart, bend; + const int is_file = !S_ISDIR(inode->i_mode); + const int write_mask = (mask & MAY_WRITE) && !(mask & MAY_READ); + + bstart = ibstart(inode); + bend = ibend(inode); + if (unlikely(bstart < 0 || bend < 0)) { + /* + * With branch-management, we can get a stale inode here. + * If so, we return ESTALE back to link_path_walk, which + * would discard the dcache entry and re-lookup the + * dentry+inode. This should be equivalent to issuing + * __unionfs_d_revalidate_chain on nd.dentry here. + */ + if (is_file) /* dirs can be unlinked but chdir'ed to */ + err = -ESTALE; /* force revalidate */ + goto out; + } + + for (bindex = bstart; bindex <= bend; bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (!lower_inode) + continue; + + /* + * check the condition for D-F-D underlying files/directories, + * we don't have to check for files, if we are checking for + * directories. + */ + if (!is_file && !S_ISDIR(lower_inode->i_mode)) + continue; + + /* + * We check basic permissions, but we ignore any conditions + * such as readonly file systems or branches marked as + * readonly, because those conditions should lead to a + * copyup taking place later on. + */ + err = permission(lower_inode, mask, nd); + if (err && bindex > 0) { + umode_t mode = lower_inode->i_mode; + if (is_robranch_super(inode->i_sb, bindex) && + (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) + err = 0; + if (IS_COPYUP_ERR(err)) + err = 0; + } + + /* + * The permissions are an intersection of the overall directory + * permissions, so we fail if one fails. + */ + if (err) + goto out; + + /* only the leftmost file matters. */ + if (is_file || write_mask) { + if (is_file && write_mask) { + err = get_write_access(lower_inode); + if (!err) + put_write_access(lower_inode); + } + break; + } + } + /* sync times which may have changed (asynchronously) below */ + unionfs_copy_attr_times(inode); + +out: + unionfs_check_inode(inode); + unionfs_check_nd(nd); + return err; +} + +static int unionfs_setattr(struct dentry *dentry, struct iattr *ia) +{ + int err = 0; + struct dentry *lower_dentry; + struct inode *inode = NULL; + struct inode *lower_inode = NULL; + int bstart, bend, bindex; + int i; + int copyup = 0; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + bstart = dbstart(dentry); + bend = dbend(dentry); + inode = dentry->d_inode; + + /* + * mode change is for clearing setuid/setgid. Allow lower filesystem + * to reinterpret it in its own way. + */ + if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) + ia->ia_valid &= ~ATTR_MODE; + + for (bindex = bstart; (bindex <= bend) || (bindex == bstart); + bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) + continue; + BUG_ON(lower_dentry->d_inode == NULL); + + /* If the file is on a read only branch */ + if (is_robranch_super(dentry->d_sb, bindex) + || IS_RDONLY(lower_dentry->d_inode)) { + if (copyup || (bindex != bstart)) + continue; + /* Only if its the leftmost file, copyup the file */ + for (i = bstart - 1; i >= 0; i--) { + loff_t size = i_size_read(dentry->d_inode); + if (ia->ia_valid & ATTR_SIZE) + size = ia->ia_size; + err = copyup_dentry(dentry->d_parent->d_inode, + dentry, bstart, i, + dentry->d_name.name, + dentry->d_name.len, + NULL, size); + + if (!err) { + copyup = 1; + lower_dentry = + unionfs_lower_dentry(dentry); + break; + } + /* + * if error is in the leftmost branch, pass + * it up. + */ + if (i == 0) + goto out; + } + + } + err = notify_change(lower_dentry, ia); + if (err) + goto out; + break; + } + + /* for mmap */ + if (ia->ia_valid & ATTR_SIZE) { + if (ia->ia_size != i_size_read(inode)) { + err = vmtruncate(inode, ia->ia_size); + if (err) + printk(KERN_ERR + "unionfs: setattr: vmtruncate failed\n"); + } + } + + /* get the size from the first lower inode */ + lower_inode = unionfs_lower_inode(inode); + unionfs_copy_attr_all(inode, lower_inode); + /* + * unionfs_copy_attr_all will copy the lower times to our inode if + * the lower ones are newer (useful for cache coherency). However, + * ->setattr is the only place in which we may have to copy the + * lower inode times absolutely, to support utimes(2). + */ + if (ia->ia_valid & ATTR_MTIME_SET) + inode->i_mtime = lower_inode->i_mtime; + if (ia->ia_valid & ATTR_CTIME) + inode->i_ctime = lower_inode->i_ctime; + if (ia->ia_valid & ATTR_ATIME_SET) + inode->i_atime = lower_inode->i_atime; + fsstack_copy_inode_size(inode, lower_inode); + /* if setattr succeeded, then parent dir may have changed */ + unionfs_copy_attr_times(dentry->d_parent->d_inode); +out: + unionfs_check_dentry(dentry); + unionfs_check_dentry(dentry->d_parent); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + + return err; +} + +struct inode_operations unionfs_symlink_iops = { + .readlink = unionfs_readlink, + .permission = unionfs_permission, + .follow_link = unionfs_follow_link, + .setattr = unionfs_setattr, + .put_link = unionfs_put_link, +}; + +struct inode_operations unionfs_dir_iops = { + .create = unionfs_create, + .lookup = unionfs_lookup, + .link = unionfs_link, + .unlink = unionfs_unlink, + .symlink = unionfs_symlink, + .mkdir = unionfs_mkdir, + .rmdir = unionfs_rmdir, + .mknod = unionfs_mknod, + .rename = unionfs_rename, + .permission = unionfs_permission, + .setattr = unionfs_setattr, +#ifdef CONFIG_UNION_FS_XATTR + .setxattr = unionfs_setxattr, + .getxattr = unionfs_getxattr, + .removexattr = unionfs_removexattr, + .listxattr = unionfs_listxattr, +#endif /* CONFIG_UNION_FS_XATTR */ +}; + +struct inode_operations unionfs_main_iops = { + .permission = unionfs_permission, + .setattr = unionfs_setattr, +#ifdef CONFIG_UNION_FS_XATTR + .setxattr = unionfs_setxattr, + .getxattr = unionfs_getxattr, + .removexattr = unionfs_removexattr, + .listxattr = unionfs_listxattr, +#endif /* CONFIG_UNION_FS_XATTR */ +}; diff -puN /dev/null fs/unionfs/lookup.c --- /dev/null +++ a/fs/unionfs/lookup.c @@ -0,0 +1,652 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +static int realloc_dentry_private_data(struct dentry *dentry); + +/* is the filename valid == !(whiteout for a file or opaque dir marker) */ +static int is_validname(const char *name) +{ + if (!strncmp(name, UNIONFS_WHPFX, UNIONFS_WHLEN)) + return 0; + if (!strncmp(name, UNIONFS_DIR_OPAQUE_NAME, + sizeof(UNIONFS_DIR_OPAQUE_NAME) - 1)) + return 0; + return 1; +} + +/* The rest of these are utility functions for lookup. */ +static noinline int is_opaque_dir(struct dentry *dentry, int bindex) +{ + int err = 0; + struct dentry *lower_dentry; + struct dentry *wh_lower_dentry; + struct inode *lower_inode; + struct sioq_args args; + + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + lower_inode = lower_dentry->d_inode; + + BUG_ON(!S_ISDIR(lower_inode->i_mode)); + + mutex_lock(&lower_inode->i_mutex); + + if (!permission(lower_inode, MAY_EXEC, NULL)) { + wh_lower_dentry = + lookup_one_len(UNIONFS_DIR_OPAQUE, lower_dentry, + sizeof(UNIONFS_DIR_OPAQUE) - 1); + } else { + args.is_opaque.dentry = lower_dentry; + run_sioq(__is_opaque_dir, &args); + wh_lower_dentry = args.ret; + } + + mutex_unlock(&lower_inode->i_mutex); + + if (IS_ERR(wh_lower_dentry)) { + err = PTR_ERR(wh_lower_dentry); + goto out; + } + + /* This is an opaque dir iff wh_lower_dentry is positive */ + err = !!wh_lower_dentry->d_inode; + + dput(wh_lower_dentry); +out: + return err; +} + +/* + * Main (and complex) driver function for Unionfs's lookup + * + * Returns: NULL (ok), ERR_PTR if an error occurred, or a non-null non-error + * PTR if d_splice returned a different dentry. + * + * If lookupmode is INTERPOSE_PARTIAL/REVAL/REVAL_NEG, the passed dentry's + * inode info must be locked. If lookupmode is INTERPOSE_LOOKUP (i.e., a + * newly looked-up dentry), then unionfs_lookup_backend will return a locked + * dentry's info, which the caller must unlock. + */ +struct dentry *unionfs_lookup_backend(struct dentry *dentry, + struct nameidata *nd, int lookupmode) +{ + int err = 0; + struct dentry *lower_dentry = NULL; + struct dentry *wh_lower_dentry = NULL; + struct dentry *lower_dir_dentry = NULL; + struct dentry *parent_dentry = NULL; + struct dentry *d_interposed = NULL; + int bindex, bstart = -1, bend, bopaque; + int dentry_count = 0; /* Number of positive dentries. */ + int first_dentry_offset = -1; /* -1 is uninitialized */ + struct dentry *first_dentry = NULL; + struct dentry *first_lower_dentry = NULL; + struct vfsmount *first_lower_mnt = NULL; + int locked_parent = 0; + int opaque; + char *whname = NULL; + const char *name; + int namelen; + + /* + * We should already have a lock on this dentry in the case of a + * partial lookup, or a revalidation. Otherwise it is returned from + * new_dentry_private_data already locked. + */ + if (lookupmode == INTERPOSE_PARTIAL || lookupmode == INTERPOSE_REVAL || + lookupmode == INTERPOSE_REVAL_NEG) + verify_locked(dentry); + else /* this could only be INTERPOSE_LOOKUP */ + BUG_ON(UNIONFS_D(dentry) != NULL); + + switch (lookupmode) { + case INTERPOSE_PARTIAL: + break; + case INTERPOSE_LOOKUP: + err = new_dentry_private_data(dentry); + if (unlikely(err)) + goto out; + break; + default: + /* default: can only be INTERPOSE_REVAL/REVAL_NEG */ + err = realloc_dentry_private_data(dentry); + if (unlikely(err)) + goto out; + break; + } + + /* must initialize dentry operations */ + dentry->d_op = &unionfs_dops; + + parent_dentry = dget_parent(dentry); + /* We never partial lookup the root directory. */ + if (parent_dentry != dentry) { + unionfs_lock_dentry(parent_dentry); + locked_parent = 1; + } else { + dput(parent_dentry); + parent_dentry = NULL; + goto out; + } + + name = dentry->d_name.name; + namelen = dentry->d_name.len; + + /* No dentries should get created for possible whiteout names. */ + if (!is_validname(name)) { + err = -EPERM; + goto out_free; + } + + /* Now start the actual lookup procedure. */ + bstart = dbstart(parent_dentry); + bend = dbend(parent_dentry); + bopaque = dbopaque(parent_dentry); + BUG_ON(bstart < 0); + + /* + * It would be ideal if we could convert partial lookups to only have + * to do this work when they really need to. It could probably improve + * performance quite a bit, and maybe simplify the rest of the code. + */ + if (lookupmode == INTERPOSE_PARTIAL) { + bstart++; + if ((bopaque != -1) && (bopaque < bend)) + bend = bopaque; + } + + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (lookupmode == INTERPOSE_PARTIAL && lower_dentry) + continue; + BUG_ON(lower_dentry != NULL); + + lower_dir_dentry = + unionfs_lower_dentry_idx(parent_dentry, bindex); + + /* if the parent lower dentry does not exist skip this */ + if (!(lower_dir_dentry && lower_dir_dentry->d_inode)) + continue; + + /* also skip it if the parent isn't a directory. */ + if (!S_ISDIR(lower_dir_dentry->d_inode->i_mode)) + continue; + + /* Reuse the whiteout name because its value doesn't change. */ + if (!whname) { + whname = alloc_whname(name, namelen); + if (unlikely(IS_ERR(whname))) { + err = PTR_ERR(whname); + goto out_free; + } + } + + /* check if whiteout exists in this branch: lookup .wh.foo */ + wh_lower_dentry = lookup_one_len(whname, lower_dir_dentry, + namelen + UNIONFS_WHLEN); + if (IS_ERR(wh_lower_dentry)) { + dput(first_lower_dentry); + unionfs_mntput(first_dentry, first_dentry_offset); + err = PTR_ERR(wh_lower_dentry); + goto out_free; + } + + if (wh_lower_dentry->d_inode) { + /* We found a whiteout so let's give up. */ + if (S_ISREG(wh_lower_dentry->d_inode->i_mode)) { + set_dbend(dentry, bindex); + set_dbopaque(dentry, bindex); + dput(wh_lower_dentry); + break; + } + err = -EIO; + printk(KERN_ERR "unionfs: EIO: invalid whiteout " + "entry type %d\n", + wh_lower_dentry->d_inode->i_mode); + dput(wh_lower_dentry); + dput(first_lower_dentry); + unionfs_mntput(first_dentry, first_dentry_offset); + goto out_free; + } + + dput(wh_lower_dentry); + wh_lower_dentry = NULL; + + /* Now do regular lookup; lookup foo */ + lower_dentry = lookup_one_len(name, lower_dir_dentry, namelen); + if (IS_ERR(lower_dentry)) { + dput(first_lower_dentry); + unionfs_mntput(first_dentry, first_dentry_offset); + err = PTR_ERR(lower_dentry); + goto out_free; + } + + /* + * Store the first negative dentry specially, because if they + * are all negative we need this for future creates. + */ + if (!lower_dentry->d_inode) { + if (!first_lower_dentry && (dbstart(dentry) == -1)) { + first_lower_dentry = lower_dentry; + /* + * FIXME: following line needs to be changed + * to allow mount-point crossing + */ + first_dentry = parent_dentry; + first_lower_mnt = + unionfs_mntget(parent_dentry, bindex); + first_dentry_offset = bindex; + } else { + dput(lower_dentry); + } + + continue; + } + + /* number of positive dentries */ + dentry_count++; + + /* store underlying dentry */ + if (dbstart(dentry) == -1) + set_dbstart(dentry, bindex); + unionfs_set_lower_dentry_idx(dentry, bindex, lower_dentry); + /* + * FIXME: the following line needs to get fixed to allow + * mount-point crossing + */ + unionfs_set_lower_mnt_idx(dentry, bindex, + unionfs_mntget(parent_dentry, + bindex)); + set_dbend(dentry, bindex); + + /* update parent directory's atime with the bindex */ + fsstack_copy_attr_atime(parent_dentry->d_inode, + lower_dir_dentry->d_inode); + + /* We terminate file lookups here. */ + if (!S_ISDIR(lower_dentry->d_inode->i_mode)) { + if (lookupmode == INTERPOSE_PARTIAL) + continue; + if (dentry_count == 1) + goto out_positive; + /* This can only happen with mixed D-*-F-* */ + BUG_ON(!S_ISDIR(unionfs_lower_dentry(dentry)-> + d_inode->i_mode)); + continue; + } + + opaque = is_opaque_dir(dentry, bindex); + if (opaque < 0) { + dput(first_lower_dentry); + unionfs_mntput(first_dentry, first_dentry_offset); + err = opaque; + goto out_free; + } else if (opaque) { + set_dbend(dentry, bindex); + set_dbopaque(dentry, bindex); + break; + } + } + + if (dentry_count) + goto out_positive; + else + goto out_negative; + +out_negative: + if (lookupmode == INTERPOSE_PARTIAL) + goto out; + + /* If we've only got negative dentries, then use the leftmost one. */ + if (lookupmode == INTERPOSE_REVAL) { + if (dentry->d_inode) + UNIONFS_I(dentry->d_inode)->stale = 1; + goto out; + } + /* This should only happen if we found a whiteout. */ + if (first_dentry_offset == -1) { + first_lower_dentry = lookup_one_len(name, lower_dir_dentry, + namelen); + first_dentry_offset = bindex; + if (IS_ERR(first_lower_dentry)) { + err = PTR_ERR(first_lower_dentry); + goto out; + } + + /* + * FIXME: the following line needs to be changed to allow + * mount-point crossing + */ + first_dentry = dentry; + first_lower_mnt = unionfs_mntget(dentry->d_sb->s_root, + bindex); + } + unionfs_set_lower_dentry_idx(dentry, first_dentry_offset, + first_lower_dentry); + unionfs_set_lower_mnt_idx(dentry, first_dentry_offset, + first_lower_mnt); + set_dbstart(dentry, first_dentry_offset); + set_dbend(dentry, first_dentry_offset); + + if (lookupmode == INTERPOSE_REVAL_NEG) + BUG_ON(dentry->d_inode != NULL); + else + d_add(dentry, NULL); + goto out; + +/* This part of the code is for positive dentries. */ +out_positive: + BUG_ON(dentry_count <= 0); + + /* + * If we're holding onto the first negative dentry & corresponding + * vfsmount - throw it out. + */ + dput(first_lower_dentry); + unionfs_mntput(first_dentry, first_dentry_offset); + + /* Partial lookups need to re-interpose, or throw away older negs. */ + if (lookupmode == INTERPOSE_PARTIAL) { + if (dentry->d_inode) { + unionfs_reinterpose(dentry); + goto out; + } + + /* + * This somehow turned positive, so it is as if we had a + * negative revalidation. + */ + lookupmode = INTERPOSE_REVAL_NEG; + + update_bstart(dentry); + bstart = dbstart(dentry); + bend = dbend(dentry); + } + + /* + * Interpose can return a dentry if d_splice returned a different + * dentry. + */ + d_interposed = unionfs_interpose(dentry, dentry->d_sb, lookupmode); + if (IS_ERR(d_interposed)) + err = PTR_ERR(d_interposed); + else if (d_interposed) + dentry = d_interposed; + + if (err) + goto out_drop; + + goto out; + +out_drop: + d_drop(dentry); + +out_free: + /* should dput all the underlying dentries on error condition */ + bstart = dbstart(dentry); + if (bstart >= 0) { + bend = dbend(dentry); + for (bindex = bstart; bindex <= bend; bindex++) { + dput(unionfs_lower_dentry_idx(dentry, bindex)); + unionfs_mntput(dentry, bindex); + } + } + kfree(UNIONFS_D(dentry)->lower_paths); + UNIONFS_D(dentry)->lower_paths = NULL; + set_dbstart(dentry, -1); + set_dbend(dentry, -1); + +out: + if (!err && UNIONFS_D(dentry)) { + BUG_ON(dbend(dentry) > UNIONFS_D(dentry)->bcount); + BUG_ON(dbend(dentry) > sbmax(dentry->d_sb)); + if (dbstart(dentry) < 0 && + dentry->d_inode && bstart >= 0 && + (!UNIONFS_I(dentry->d_inode) || + !UNIONFS_I(dentry->d_inode)->lower_inodes)) { + unionfs_mntput(dentry->d_sb->s_root, bstart); + dput(first_lower_dentry); + UNIONFS_I(dentry->d_inode)->stale = 1; + } + } + kfree(whname); + if (locked_parent) + unionfs_unlock_dentry(parent_dentry); + dput(parent_dentry); + if (err && (lookupmode == INTERPOSE_LOOKUP)) + unionfs_unlock_dentry(dentry); + if (!err && d_interposed) + return d_interposed; + if (dentry->d_inode && UNIONFS_I(dentry->d_inode)->stale && + first_dentry_offset >= 0) + unionfs_mntput(dentry->d_sb->s_root, first_dentry_offset); + return ERR_PTR(err); +} + +/* + * This is a utility function that fills in a unionfs dentry. + * + * Returns: 0 (ok), or -ERRNO if an error occurred. + */ +int unionfs_partial_lookup(struct dentry *dentry) +{ + struct dentry *tmp; + struct nameidata nd = { .flags = 0 }; + int err = -ENOSYS; + + tmp = unionfs_lookup_backend(dentry, &nd, INTERPOSE_PARTIAL); + if (!tmp) { + err = 0; + goto out; + } + if (IS_ERR(tmp)) { + err = PTR_ERR(tmp); + goto out; + } + /* need to change the interface */ + BUG_ON(tmp != dentry); +out: + return err; +} + +/* The dentry cache is just so we have properly sized dentries. */ +static struct kmem_cache *unionfs_dentry_cachep; +int unionfs_init_dentry_cache(void) +{ + unionfs_dentry_cachep = + kmem_cache_create("unionfs_dentry", + sizeof(struct unionfs_dentry_info), + 0, SLAB_RECLAIM_ACCOUNT, NULL); + + return (unionfs_dentry_cachep ? 0 : -ENOMEM); +} + +void unionfs_destroy_dentry_cache(void) +{ + if (unionfs_dentry_cachep) + kmem_cache_destroy(unionfs_dentry_cachep); +} + +void free_dentry_private_data(struct dentry *dentry) +{ + if (!dentry || !dentry->d_fsdata) + return; + kmem_cache_free(unionfs_dentry_cachep, dentry->d_fsdata); + dentry->d_fsdata = NULL; +} + +static inline int __realloc_dentry_private_data(struct dentry *dentry) +{ + struct unionfs_dentry_info *info = UNIONFS_D(dentry); + void *p; + int size; + + BUG_ON(!info); + + size = sizeof(struct path) * sbmax(dentry->d_sb); + p = krealloc(info->lower_paths, size, GFP_ATOMIC); + if (unlikely(!p)) + return -ENOMEM; + + info->lower_paths = p; + + info->bstart = -1; + info->bend = -1; + info->bopaque = -1; + info->bcount = sbmax(dentry->d_sb); + atomic_set(&info->generation, + atomic_read(&UNIONFS_SB(dentry->d_sb)->generation)); + + memset(info->lower_paths, 0, size); + + return 0; +} + +/* UNIONFS_D(dentry)->lock must be locked */ +static int realloc_dentry_private_data(struct dentry *dentry) +{ + if (!__realloc_dentry_private_data(dentry)) + return 0; + + kfree(UNIONFS_D(dentry)->lower_paths); + free_dentry_private_data(dentry); + return -ENOMEM; +} + +/* allocate new dentry private data */ +int new_dentry_private_data(struct dentry *dentry) +{ + struct unionfs_dentry_info *info = UNIONFS_D(dentry); + + BUG_ON(info); + + info = kmem_cache_alloc(unionfs_dentry_cachep, GFP_ATOMIC); + if (unlikely(!info)) + return -ENOMEM; + + mutex_init(&info->lock); + mutex_lock(&info->lock); + + info->lower_paths = NULL; + + dentry->d_fsdata = info; + + if (!__realloc_dentry_private_data(dentry)) + return 0; + + mutex_unlock(&info->lock); + free_dentry_private_data(dentry); + return -ENOMEM; +} + +/* + * scan through the lower dentry objects, and set bstart to reflect the + * starting branch + */ +void update_bstart(struct dentry *dentry) +{ + int bindex; + int bstart = dbstart(dentry); + int bend = dbend(dentry); + struct dentry *lower_dentry; + + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) + continue; + if (lower_dentry->d_inode) { + set_dbstart(dentry, bindex); + break; + } + dput(lower_dentry); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + } +} + + +/* + * Initialize a nameidata structure (the intent part) we can pass to a lower + * file system. Returns 0 on success or -error (only -ENOMEM possible). + * Inside that nd structure, this function may also return an allocated + * struct file (for open intents). The caller, when done with this nd, must + * kfree the intent file (using release_lower_nd). + * + * XXX: this code, and the callers of this code, should be redone using + * vfs_path_lookup() when (1) the nameidata structure is refactored into a + * separate intent-structure, and (2) open_namei() is broken into a VFS-only + * function and a method that other file systems can call. + */ +int init_lower_nd(struct nameidata *nd, unsigned int flags) +{ + int err = 0; +#ifdef ALLOC_LOWER_ND_FILE + /* + * XXX: one day we may need to have the lower return an open file + * for us. It is not needed in 2.6.23-rc1 for nfs2/nfs3, but may + * very well be needed for nfs4. + */ + struct file *file; +#endif /* ALLOC_LOWER_ND_FILE */ + + memset(nd, 0, sizeof(struct nameidata)); + if (!flags) + return err; + + switch (flags) { + case LOOKUP_CREATE: + nd->intent.open.flags |= O_CREAT; + /* fall through: shared code for create/open cases */ + case LOOKUP_OPEN: + nd->flags = flags; + nd->intent.open.flags |= (FMODE_READ | FMODE_WRITE); +#ifdef ALLOC_LOWER_ND_FILE + file = kzalloc(sizeof(struct file), GFP_KERNEL); + if (unlikely(!file)) { + err = -ENOMEM; + break; /* exit switch statement and thus return */ + } + nd->intent.open.file = file; +#endif /* ALLOC_LOWER_ND_FILE */ + break; + case LOOKUP_ACCESS: + nd->flags = flags; + break; + default: + /* + * We should never get here, for now. + * We can add new cases here later on. + */ + pr_debug("unionfs: unknown nameidata flag 0x%x\n", flags); + BUG(); + break; + } + + return err; +} + +void release_lower_nd(struct nameidata *nd, int err) +{ + if (!nd->intent.open.file) + return; + else if (!err) + release_open_intent(nd); +#ifdef ALLOC_LOWER_ND_FILE + kfree(nd->intent.open.file); +#endif /* ALLOC_LOWER_ND_FILE */ +} diff -puN /dev/null fs/unionfs/main.c --- /dev/null +++ a/fs/unionfs/main.c @@ -0,0 +1,783 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" +#include +#include + +static void unionfs_fill_inode(struct dentry *dentry, + struct inode *inode) +{ + struct inode *lower_inode; + struct dentry *lower_dentry; + int bindex, bstart, bend; + + bstart = dbstart(dentry); + bend = dbend(dentry); + + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) { + unionfs_set_lower_inode_idx(inode, bindex, NULL); + continue; + } + + /* Initialize the lower inode to the new lower inode. */ + if (!lower_dentry->d_inode) + continue; + + unionfs_set_lower_inode_idx(inode, bindex, + igrab(lower_dentry->d_inode)); + } + + ibstart(inode) = dbstart(dentry); + ibend(inode) = dbend(dentry); + + /* Use attributes from the first branch. */ + lower_inode = unionfs_lower_inode(inode); + + /* Use different set of inode ops for symlinks & directories */ + if (S_ISLNK(lower_inode->i_mode)) + inode->i_op = &unionfs_symlink_iops; + else if (S_ISDIR(lower_inode->i_mode)) + inode->i_op = &unionfs_dir_iops; + + /* Use different set of file ops for directories */ + if (S_ISDIR(lower_inode->i_mode)) + inode->i_fop = &unionfs_dir_fops; + + /* properly initialize special inodes */ + if (S_ISBLK(lower_inode->i_mode) || S_ISCHR(lower_inode->i_mode) || + S_ISFIFO(lower_inode->i_mode) || S_ISSOCK(lower_inode->i_mode)) + init_special_inode(inode, lower_inode->i_mode, + lower_inode->i_rdev); + + /* all well, copy inode attributes */ + unionfs_copy_attr_all(inode, lower_inode); + fsstack_copy_inode_size(inode, lower_inode); +} + +/* + * Connect a unionfs inode dentry/inode with several lower ones. This is + * the classic stackable file system "vnode interposition" action. + * + * @sb: unionfs's super_block + */ +struct dentry *unionfs_interpose(struct dentry *dentry, struct super_block *sb, + int flag) +{ + int err = 0; + struct inode *inode; + int is_negative_dentry = 1; + int bindex, bstart, bend; + int need_fill_inode = 1; + struct dentry *spliced = NULL; + + verify_locked(dentry); + + bstart = dbstart(dentry); + bend = dbend(dentry); + + /* Make sure that we didn't get a negative dentry. */ + for (bindex = bstart; bindex <= bend; bindex++) { + if (unionfs_lower_dentry_idx(dentry, bindex) && + unionfs_lower_dentry_idx(dentry, bindex)->d_inode) { + is_negative_dentry = 0; + break; + } + } + BUG_ON(is_negative_dentry); + + /* + * We allocate our new inode below, by calling iget. + * iget will call our read_inode which will initialize some + * of the new inode's fields + */ + + /* + * On revalidate we've already got our own inode and just need + * to fix it up. + */ + if (flag == INTERPOSE_REVAL) { + inode = dentry->d_inode; + UNIONFS_I(inode)->bstart = -1; + UNIONFS_I(inode)->bend = -1; + atomic_set(&UNIONFS_I(inode)->generation, + atomic_read(&UNIONFS_SB(sb)->generation)); + + UNIONFS_I(inode)->lower_inodes = + kcalloc(sbmax(sb), sizeof(struct inode *), GFP_KERNEL); + if (unlikely(!UNIONFS_I(inode)->lower_inodes)) { + err = -ENOMEM; + goto out; + } + } else { + /* get unique inode number for unionfs */ + inode = iget(sb, iunique(sb, UNIONFS_ROOT_INO)); + if (!inode) { + err = -EACCES; + goto out; + } + if (atomic_read(&inode->i_count) > 1) + goto skip; + } + + need_fill_inode = 0; + unionfs_fill_inode(dentry, inode); + +skip: + /* only (our) lookup wants to do a d_add */ + switch (flag) { + case INTERPOSE_DEFAULT: + case INTERPOSE_REVAL_NEG: + d_instantiate(dentry, inode); + break; + case INTERPOSE_LOOKUP: + spliced = d_splice_alias(inode, dentry); + if (IS_ERR(spliced)) { + err = PTR_ERR(spliced); + } else if (spliced && spliced != dentry) { + /* + * d_splice can return a dentry if it was + * disconnected and had to be moved. We must ensure + * that the private data of the new dentry is + * correct and that the inode info was filled + * properly. Finally we must return this new + * dentry. + */ + spliced->d_op = &unionfs_dops; + spliced->d_fsdata = dentry->d_fsdata; + dentry->d_fsdata = NULL; + dentry = spliced; + if (need_fill_inode) { + need_fill_inode = 0; + unionfs_fill_inode(dentry, inode); + } + goto out_spliced; + } + break; + case INTERPOSE_REVAL: + /* Do nothing. */ + break; + default: + printk(KERN_CRIT "unionfs: invalid interpose flag passed!\n"); + BUG(); + } + goto out; + +out_spliced: + if (!err) + return spliced; +out: + return ERR_PTR(err); +} + +/* like interpose above, but for an already existing dentry */ +void unionfs_reinterpose(struct dentry *dentry) +{ + struct dentry *lower_dentry; + struct inode *inode; + int bindex, bstart, bend; + + verify_locked(dentry); + + /* This is pre-allocated inode */ + inode = dentry->d_inode; + + bstart = dbstart(dentry); + bend = dbend(dentry); + for (bindex = bstart; bindex <= bend; bindex++) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) + continue; + + if (!lower_dentry->d_inode) + continue; + if (unionfs_lower_inode_idx(inode, bindex)) + continue; + unionfs_set_lower_inode_idx(inode, bindex, + igrab(lower_dentry->d_inode)); + } + ibstart(inode) = dbstart(dentry); + ibend(inode) = dbend(dentry); +} + +/* + * make sure the branch we just looked up (nd) makes sense: + * + * 1) we're not trying to stack unionfs on top of unionfs + * 2) it exists + * 3) is a directory + */ +int check_branch(struct nameidata *nd) +{ + /* XXX: remove in ODF code -- stacking unions allowed there */ + if (!strcmp(nd->dentry->d_sb->s_type->name, UNIONFS_NAME)) + return -EINVAL; + if (!nd->dentry->d_inode) + return -ENOENT; + if (!S_ISDIR(nd->dentry->d_inode->i_mode)) + return -ENOTDIR; + return 0; +} + +/* checks if two lower_dentries have overlapping branches */ +static int is_branch_overlap(struct dentry *dent1, struct dentry *dent2) +{ + struct dentry *dent = NULL; + + dent = dent1; + while ((dent != dent2) && (dent->d_parent != dent)) + dent = dent->d_parent; + + if (dent == dent2) + return 1; + + dent = dent2; + while ((dent != dent1) && (dent->d_parent != dent)) + dent = dent->d_parent; + + return (dent == dent1); +} + +/* + * Parse "ro" or "rw" options, but default to "rw" if no mode options was + * specified. Fill the mode bits in @perms. If encounter an unknown + * string, return -EINVAL. Otherwise return 0. + */ +int parse_branch_mode(const char *name, int *perms) +{ + if (!name || !strcmp(name, "rw")) { + *perms = MAY_READ | MAY_WRITE; + return 0; + } + if (!strcmp(name, "ro")) { + *perms = MAY_READ; + return 0; + } + return -EINVAL; +} + +/* + * parse the dirs= mount argument + * + * We don't need to lock the superblock private data's rwsem, as we get + * called only by unionfs_read_super - it is still a long time before anyone + * can even get a reference to us. + */ +static int parse_dirs_option(struct super_block *sb, struct unionfs_dentry_info + *lower_root_info, char *options) +{ + struct nameidata nd; + char *name; + int err = 0; + int branches = 1; + int bindex = 0; + int i = 0; + int j = 0; + struct dentry *dent1; + struct dentry *dent2; + + if (options[0] == '\0') { + printk(KERN_ERR "unionfs: no branches specified\n"); + err = -EINVAL; + goto out; + } + + /* + * Each colon means we have a separator, this is really just a rough + * guess, since strsep will handle empty fields for us. + */ + for (i = 0; options[i]; i++) + if (options[i] == ':') + branches++; + + /* allocate space for underlying pointers to lower dentry */ + UNIONFS_SB(sb)->data = + kcalloc(branches, sizeof(struct unionfs_data), GFP_KERNEL); + if (unlikely(!UNIONFS_SB(sb)->data)) { + err = -ENOMEM; + goto out; + } + + lower_root_info->lower_paths = + kcalloc(branches, sizeof(struct path), GFP_KERNEL); + if (unlikely(!lower_root_info->lower_paths)) { + err = -ENOMEM; + goto out; + } + + /* now parsing a string such as "b1:b2=rw:b3=ro:b4" */ + branches = 0; + while ((name = strsep(&options, ":")) != NULL) { + int perms; + char *mode = strchr(name, '='); + + if (!name) + continue; + if (!*name) { /* bad use of ':' (extra colons) */ + err = -EINVAL; + goto out; + } + + branches++; + + /* strip off '=' if any */ + if (mode) + *mode++ = '\0'; + + err = parse_branch_mode(mode, &perms); + if (err) { + printk(KERN_ERR "unionfs: invalid mode \"%s\" for " + "branch %d\n", mode, bindex); + goto out; + } + /* ensure that leftmost branch is writeable */ + if (!bindex && !(perms & MAY_WRITE)) { + printk(KERN_ERR "unionfs: leftmost branch cannot be " + "read-only (use \"-o ro\" to create a " + "read-only union)\n"); + err = -EINVAL; + goto out; + } + + err = path_lookup(name, LOOKUP_FOLLOW, &nd); + if (err) { + printk(KERN_ERR "unionfs: error accessing " + "lower directory '%s' (error %d)\n", + name, err); + goto out; + } + + err = check_branch(&nd); + if (err) { + printk(KERN_ERR "unionfs: lower directory " + "'%s' is not a valid branch\n", name); + path_release(&nd); + goto out; + } + + lower_root_info->lower_paths[bindex].dentry = nd.dentry; + lower_root_info->lower_paths[bindex].mnt = nd.mnt; + + set_branchperms(sb, bindex, perms); + set_branch_count(sb, bindex, 0); + new_branch_id(sb, bindex); + + if (lower_root_info->bstart < 0) + lower_root_info->bstart = bindex; + lower_root_info->bend = bindex; + bindex++; + } + + if (branches == 0) { + printk(KERN_ERR "unionfs: no branches specified\n"); + err = -EINVAL; + goto out; + } + + BUG_ON(branches != (lower_root_info->bend + 1)); + + /* + * Ensure that no overlaps exist in the branches. + * + * This test is required because the Linux kernel has no support + * currently for ensuring coherency between stackable layers and + * branches. If we were to allow overlapping branches, it would be + * possible, for example, to delete a file via one branch, which + * would not be reflected in another branch. Such incoherency could + * lead to inconsistencies and even kernel oopses. Rather than + * implement hacks to work around some of these cache-coherency + * problems, we prevent branch overlapping, for now. A complete + * solution will involve proper kernel/VFS support for cache + * coherency, at which time we could safely remove this + * branch-overlapping test. + */ + for (i = 0; i < branches; i++) { + dent1 = lower_root_info->lower_paths[i].dentry; + for (j = i + 1; j < branches; j++) { + dent2 = lower_root_info->lower_paths[j].dentry; + if (is_branch_overlap(dent1, dent2)) { + printk(KERN_ERR "unionfs: branches %d and " + "%d overlap\n", i, j); + err = -EINVAL; + goto out; + } + } + } + +out: + if (err) { + for (i = 0; i < branches; i++) + if (lower_root_info->lower_paths[i].dentry) { + dput(lower_root_info->lower_paths[i].dentry); + /* initialize: can't use unionfs_mntput here */ + mntput(lower_root_info->lower_paths[i].mnt); + } + + kfree(lower_root_info->lower_paths); + kfree(UNIONFS_SB(sb)->data); + + /* + * MUST clear the pointers to prevent potential double free if + * the caller dies later on + */ + lower_root_info->lower_paths = NULL; + UNIONFS_SB(sb)->data = NULL; + } + return err; +} + +/* + * Parse mount options. See the manual page for usage instructions. + * + * Returns the dentry object of the lower-level (lower) directory; + * We want to mount our stackable file system on top of that lower directory. + */ +static struct unionfs_dentry_info *unionfs_parse_options( + struct super_block *sb, + char *options) +{ + struct unionfs_dentry_info *lower_root_info; + char *optname; + int err = 0; + int bindex; + int dirsfound = 0; + + /* allocate private data area */ + err = -ENOMEM; + lower_root_info = + kzalloc(sizeof(struct unionfs_dentry_info), GFP_KERNEL); + if (unlikely(!lower_root_info)) + goto out_error; + lower_root_info->bstart = -1; + lower_root_info->bend = -1; + lower_root_info->bopaque = -1; + + while ((optname = strsep(&options, ",")) != NULL) { + char *optarg; + char *endptr; + int intval; + + if (!optname || !*optname) + continue; + + optarg = strchr(optname, '='); + if (optarg) + *optarg++ = '\0'; + + /* + * All of our options take an argument now. Insert ones that + * don't, above this check. + */ + if (!optarg) { + printk(KERN_ERR "unionfs: %s requires an argument\n", + optname); + err = -EINVAL; + goto out_error; + } + + if (!strcmp("dirs", optname)) { + if (++dirsfound > 1) { + printk(KERN_ERR + "unionfs: multiple dirs specified\n"); + err = -EINVAL; + goto out_error; + } + err = parse_dirs_option(sb, lower_root_info, optarg); + if (err) + goto out_error; + continue; + } + + /* All of these options require an integer argument. */ + intval = simple_strtoul(optarg, &endptr, 0); + if (*endptr) { + printk(KERN_ERR + "unionfs: invalid %s option '%s'\n", + optname, optarg); + err = -EINVAL; + goto out_error; + } + + err = -EINVAL; + printk(KERN_ERR + "unionfs: unrecognized option '%s'\n", optname); + goto out_error; + } + if (dirsfound != 1) { + printk(KERN_ERR "unionfs: dirs option required\n"); + err = -EINVAL; + goto out_error; + } + goto out; + +out_error: + if (lower_root_info && lower_root_info->lower_paths) { + for (bindex = lower_root_info->bstart; + bindex >= 0 && bindex <= lower_root_info->bend; + bindex++) { + struct dentry *d; + struct vfsmount *m; + + d = lower_root_info->lower_paths[bindex].dentry; + m = lower_root_info->lower_paths[bindex].mnt; + + dput(d); + /* initializing: can't use unionfs_mntput here */ + mntput(m); + } + } + + kfree(lower_root_info->lower_paths); + kfree(lower_root_info); + + kfree(UNIONFS_SB(sb)->data); + UNIONFS_SB(sb)->data = NULL; + + lower_root_info = ERR_PTR(err); +out: + return lower_root_info; +} + +/* + * our custom d_alloc_root work-alike + * + * we can't use d_alloc_root if we want to use our own interpose function + * unchanged, so we simply call our own "fake" d_alloc_root + */ +static struct dentry *unionfs_d_alloc_root(struct super_block *sb) +{ + struct dentry *ret = NULL; + + if (sb) { + static const struct qstr name = { + .name = "/", + .len = 1 + }; + + ret = d_alloc(NULL, &name); + if (likely(ret)) { + ret->d_op = &unionfs_dops; + ret->d_sb = sb; + ret->d_parent = ret; + } + } + return ret; +} + +/* + * There is no need to lock the unionfs_super_info's rwsem as there is no + * way anyone can have a reference to the superblock at this point in time. + */ +static int unionfs_read_super(struct super_block *sb, void *raw_data, + int silent) +{ + int err = 0; + struct unionfs_dentry_info *lower_root_info = NULL; + int bindex, bstart, bend; + + if (!raw_data) { + printk(KERN_ERR + "unionfs: read_super: missing data argument\n"); + err = -EINVAL; + goto out; + } + + /* Allocate superblock private data */ + sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL); + if (unlikely(!UNIONFS_SB(sb))) { + printk(KERN_CRIT "unionfs: read_super: out of memory\n"); + err = -ENOMEM; + goto out; + } + + UNIONFS_SB(sb)->bend = -1; + atomic_set(&UNIONFS_SB(sb)->generation, 1); + init_rwsem(&UNIONFS_SB(sb)->rwsem); + UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */ + + lower_root_info = unionfs_parse_options(sb, raw_data); + if (IS_ERR(lower_root_info)) { + printk(KERN_ERR + "unionfs: read_super: error while parsing options " + "(err = %ld)\n", PTR_ERR(lower_root_info)); + err = PTR_ERR(lower_root_info); + lower_root_info = NULL; + goto out_free; + } + if (lower_root_info->bstart == -1) { + err = -ENOENT; + goto out_free; + } + + /* set the lower superblock field of upper superblock */ + bstart = lower_root_info->bstart; + BUG_ON(bstart != 0); + sbend(sb) = bend = lower_root_info->bend; + for (bindex = bstart; bindex <= bend; bindex++) { + struct dentry *d = lower_root_info->lower_paths[bindex].dentry; + unionfs_set_lower_super_idx(sb, bindex, d->d_sb); + } + + /* max Bytes is the maximum bytes from highest priority branch */ + sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes; + + sb->s_op = &unionfs_sops; + + /* See comment next to the definition of unionfs_d_alloc_root */ + sb->s_root = unionfs_d_alloc_root(sb); + if (unlikely(!sb->s_root)) { + err = -ENOMEM; + goto out_dput; + } + + /* link the upper and lower dentries */ + sb->s_root->d_fsdata = NULL; + err = new_dentry_private_data(sb->s_root); + if (unlikely(err)) + goto out_freedpd; + + /* Set the lower dentries for s_root */ + for (bindex = bstart; bindex <= bend; bindex++) { + struct dentry *d; + struct vfsmount *m; + + d = lower_root_info->lower_paths[bindex].dentry; + m = lower_root_info->lower_paths[bindex].mnt; + + unionfs_set_lower_dentry_idx(sb->s_root, bindex, d); + unionfs_set_lower_mnt_idx(sb->s_root, bindex, m); + } + set_dbstart(sb->s_root, bstart); + set_dbend(sb->s_root, bend); + + /* Set the generation number to one, since this is for the mount. */ + atomic_set(&UNIONFS_D(sb->s_root)->generation, 1); + + /* + * Call interpose to create the upper level inode. Only + * INTERPOSE_LOOKUP can return a value other than 0 on err. + */ + err = PTR_ERR(unionfs_interpose(sb->s_root, sb, 0)); + unionfs_unlock_dentry(sb->s_root); + if (!err) + goto out; + /* else fall through */ + +out_freedpd: + if (UNIONFS_D(sb->s_root)) { + kfree(UNIONFS_D(sb->s_root)->lower_paths); + free_dentry_private_data(sb->s_root); + } + dput(sb->s_root); + +out_dput: + if (lower_root_info && !IS_ERR(lower_root_info)) { + for (bindex = lower_root_info->bstart; + bindex <= lower_root_info->bend; bindex++) { + struct dentry *d; + struct vfsmount *m; + + d = lower_root_info->lower_paths[bindex].dentry; + m = lower_root_info->lower_paths[bindex].mnt; + + dput(d); + /* initializing: can't use unionfs_mntput here */ + mntput(m); + } + kfree(lower_root_info->lower_paths); + kfree(lower_root_info); + lower_root_info = NULL; + } + +out_free: + kfree(UNIONFS_SB(sb)->data); + kfree(UNIONFS_SB(sb)); + sb->s_fs_info = NULL; + +out: + if (lower_root_info && !IS_ERR(lower_root_info)) { + kfree(lower_root_info->lower_paths); + kfree(lower_root_info); + } + return err; +} + +static int unionfs_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, + void *raw_data, struct vfsmount *mnt) +{ + return get_sb_nodev(fs_type, flags, raw_data, unionfs_read_super, mnt); +} + +static struct file_system_type unionfs_fs_type = { + .owner = THIS_MODULE, + .name = UNIONFS_NAME, + .get_sb = unionfs_get_sb, + .kill_sb = generic_shutdown_super, + .fs_flags = FS_REVAL_DOT, +}; + +static int __init init_unionfs_fs(void) +{ + int err; + + pr_info("Registering unionfs " UNIONFS_VERSION "\n"); + + err = unionfs_init_filldir_cache(); + if (unlikely(err)) + goto out; + err = unionfs_init_inode_cache(); + if (unlikely(err)) + goto out; + err = unionfs_init_dentry_cache(); + if (unlikely(err)) + goto out; + err = init_sioq(); + if (unlikely(err)) + goto out; + err = register_filesystem(&unionfs_fs_type); +out: + if (unlikely(err)) { + stop_sioq(); + unionfs_destroy_filldir_cache(); + unionfs_destroy_inode_cache(); + unionfs_destroy_dentry_cache(); + } + return err; +} + +static void __exit exit_unionfs_fs(void) +{ + stop_sioq(); + unionfs_destroy_filldir_cache(); + unionfs_destroy_inode_cache(); + unionfs_destroy_dentry_cache(); + unregister_filesystem(&unionfs_fs_type); + pr_info("Completed unionfs module unload\n"); +} + +MODULE_AUTHOR("Erez Zadok, Filesystems and Storage Lab, Stony Brook University" + " (http://www.fsl.cs.sunysb.edu)"); +MODULE_DESCRIPTION("Unionfs " UNIONFS_VERSION + " (http://unionfs.filesystems.org)"); +MODULE_LICENSE("GPL"); + +module_init(init_unionfs_fs); +module_exit(exit_unionfs_fs); diff -puN /dev/null fs/unionfs/mmap.c --- /dev/null +++ a/fs/unionfs/mmap.c @@ -0,0 +1,338 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2006 Shaya Potter + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +static int unionfs_writepage(struct page *page, struct writeback_control *wbc) +{ + int err = -EIO; + struct inode *inode; + struct inode *lower_inode; + struct page *lower_page; + struct address_space *lower_mapping; /* lower inode mapping */ + gfp_t mask; + + BUG_ON(!PageUptodate(page)); + inode = page->mapping->host; + lower_inode = unionfs_lower_inode(inode); + lower_mapping = lower_inode->i_mapping; + + /* + * find lower page (returns a locked page) + * + * We turn off __GFP_FS while we look for or create a new lower + * page. This prevents a recursion into the file system code, which + * under memory pressure conditions could lead to a deadlock. This + * is similar to how the loop driver behaves (see loop_set_fd in + * drivers/block/loop.c). If we can't find the lower page, we + * redirty our page and return "success" so that the VM will call us + * again in the (hopefully near) future. + */ + mask = mapping_gfp_mask(lower_mapping) & ~(__GFP_FS); + lower_page = find_or_create_page(lower_mapping, page->index, mask); + if (!lower_page) { + err = 0; + set_page_dirty(page); + goto out; + } + + /* copy page data from our upper page to the lower page */ + copy_highpage(lower_page, page); + flush_dcache_page(lower_page); + SetPageUptodate(lower_page); + set_page_dirty(lower_page); + + /* + * Call lower writepage (expects locked page). However, if we are + * called with wbc->for_reclaim, then the VFS/VM just wants to + * reclaim our page. Therefore, we don't need to call the lower + * ->writepage: just copy our data to the lower page (already done + * above), then mark the lower page dirty and unlock it, and return + * success. + */ + if (wbc->for_reclaim) { + unlock_page(lower_page); + goto out_release; + } + + BUG_ON(!lower_mapping->a_ops->writepage); + wait_on_page_writeback(lower_page); /* prevent multiple writers */ + clear_page_dirty_for_io(lower_page); /* emulate VFS behavior */ + err = lower_mapping->a_ops->writepage(lower_page, wbc); + if (err < 0) + goto out_release; + + /* + * Lower file systems such as ramfs and tmpfs, may return + * AOP_WRITEPAGE_ACTIVATE so that the VM won't try to (pointlessly) + * write the page again for a while. But those lower file systems + * also set the page dirty bit back again. Since we successfully + * copied our page data to the lower page, then the VM will come + * back to the lower page (directly) and try to flush it. So we can + * save the VM the hassle of coming back to our page and trying to + * flush too. Therefore, we don't re-dirty our own page, and we + * never return AOP_WRITEPAGE_ACTIVATE back to the VM (we consider + * this a success). + * + * We also unlock the lower page if the lower ->writepage returned + * AOP_WRITEPAGE_ACTIVATE. (This "anomalous" behaviour may be + * addressed in future shmem/VM code.) + */ + if (err == AOP_WRITEPAGE_ACTIVATE) { + err = 0; + unlock_page(lower_page); + } + + /* all is well */ + + /* lower mtimes have changed: update ours */ + unionfs_copy_attr_times(inode); + +out_release: + /* b/c find_or_create_page increased refcnt */ + page_cache_release(lower_page); +out: + /* + * We unlock our page unconditionally, because we never return + * AOP_WRITEPAGE_ACTIVATE. + */ + unlock_page(page); + return err; +} + +static int unionfs_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + int err = 0; + struct inode *lower_inode; + struct inode *inode; + + inode = mapping->host; + if (ibstart(inode) < 0 && ibend(inode) < 0) + goto out; + lower_inode = unionfs_lower_inode(inode); + if (!lower_inode) + goto out; + + if (!mapping_cap_writeback_dirty(lower_inode->i_mapping)) + goto out; + + err = generic_writepages(mapping, wbc); + if (!err) + unionfs_copy_attr_times(inode); +out: + return err; +} + +/* Readpage expects a locked page, and must unlock it */ +static int unionfs_readpage(struct file *file, struct page *page) +{ + int err; + struct file *lower_file; + struct inode *inode; + mm_segment_t old_fs; + char *page_data = NULL; + mode_t orig_mode; + + unionfs_read_lock(file->f_path.dentry->d_sb); + err = unionfs_file_revalidate(file, false); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + if (!UNIONFS_F(file)) { + err = -ENOENT; + goto out; + } + + lower_file = unionfs_lower_file(file); + /* FIXME: is this assertion right here? */ + BUG_ON(lower_file == NULL); + + inode = file->f_path.dentry->d_inode; + + page_data = (char *) kmap(page); + /* + * Use vfs_read because some lower file systems don't have a + * readpage method, and some file systems (esp. distributed ones) + * don't like their pages to be accessed directly. Using vfs_read + * may be a little slower, but a lot safer, as the VFS does a lot of + * the necessary magic for us. + */ + lower_file->f_pos = page_offset(page); + old_fs = get_fs(); + set_fs(KERNEL_DS); + /* + * generic_file_splice_write may call us on a file not opened for + * reading, so temporarily allow reading. + */ + orig_mode = lower_file->f_mode; + lower_file->f_mode |= FMODE_READ; + err = vfs_read(lower_file, page_data, PAGE_CACHE_SIZE, + &lower_file->f_pos); + lower_file->f_mode = orig_mode; + set_fs(old_fs); + if (err >= 0 && err < PAGE_CACHE_SIZE) + memset(page_data + err, 0, PAGE_CACHE_SIZE - err); + kunmap(page); + + if (err < 0) + goto out; + err = 0; + + /* if vfs_read succeeded above, sync up our times */ + unionfs_copy_attr_times(inode); + + flush_dcache_page(page); + + /* + * we have to unlock our page, b/c we _might_ have gotten a locked + * page. but we no longer have to wakeup on our page here, b/c + * UnlockPage does it + */ +out: + if (err == 0) + SetPageUptodate(page); + else + ClearPageUptodate(page); + + unlock_page(page); + unionfs_check_file(file); + unionfs_read_unlock(file->f_path.dentry->d_sb); + + return err; +} + +static int unionfs_prepare_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + int err; + + unionfs_read_lock(file->f_path.dentry->d_sb); + /* + * This is the only place where we unconditionally copy the lower + * attribute times before calling unionfs_file_revalidate. The + * reason is that our ->write calls do_sync_write which in turn will + * call our ->prepare_write and then ->commit_write. Before our + * ->write is called, the lower mtimes are in sync, but by the time + * the VFS calls our ->commit_write, the lower mtimes have changed. + * Therefore, the only reasonable time for us to sync up from the + * changed lower mtimes, and avoid an invariant violation warning, + * is here, in ->prepare_write. + */ + unionfs_copy_attr_times(file->f_path.dentry->d_inode); + err = unionfs_file_revalidate(file, true); + unionfs_check_file(file); + unionfs_read_unlock(file->f_path.dentry->d_sb); + + return err; +} + +static int unionfs_commit_write(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + int err = -ENOMEM; + struct inode *inode, *lower_inode; + struct file *lower_file = NULL; + unsigned bytes = to - from; + char *page_data = NULL; + mm_segment_t old_fs; + + BUG_ON(file == NULL); + + unionfs_read_lock(file->f_path.dentry->d_sb); + err = unionfs_file_revalidate(file, true); + if (unlikely(err)) + goto out; + unionfs_check_file(file); + + inode = page->mapping->host; + lower_inode = unionfs_lower_inode(inode); + + if (UNIONFS_F(file) != NULL) + lower_file = unionfs_lower_file(file); + + /* FIXME: is this assertion right here? */ + BUG_ON(lower_file == NULL); + + page_data = (char *)kmap(page); + lower_file->f_pos = page_offset(page) + from; + + /* + * We use vfs_write instead of copying page data and the + * prepare_write/commit_write combo because file system's like + * GFS/OCFS2 don't like things touching those directly, + * calling the underlying write op, while a little bit slower, will + * call all the FS specific code as well + */ + old_fs = get_fs(); + set_fs(KERNEL_DS); + err = vfs_write(lower_file, page_data + from, bytes, + &lower_file->f_pos); + set_fs(old_fs); + + kunmap(page); + + if (err < 0) + goto out; + + /* if vfs_write succeeded above, sync up our times/sizes */ + fsstack_copy_inode_size(inode, lower_inode); + unionfs_copy_attr_times(inode); + mark_inode_dirty_sync(inode); + +out: + if (err < 0) + ClearPageUptodate(page); + + unionfs_check_file(file); + unionfs_read_unlock(file->f_path.dentry->d_sb); + return err; /* assume all is ok */ +} + +/* + * Although unionfs isn't a block-based file system, it may stack on one. + * ->bmap is needed, for example, to swapon(2) files. + */ +sector_t unionfs_bmap(struct address_space *mapping, sector_t block) +{ + int err = -EINVAL; + struct inode *inode, *lower_inode; + sector_t (*bmap)(struct address_space *, sector_t); + + inode = (struct inode *)mapping->host; + lower_inode = unionfs_lower_inode(inode); + if (!lower_inode) + goto out; + bmap = lower_inode->i_mapping->a_ops->bmap; + if (bmap) + err = bmap(lower_inode->i_mapping, block); +out: + return err; +} + + +struct address_space_operations unionfs_aops = { + .writepage = unionfs_writepage, + .writepages = unionfs_writepages, + .readpage = unionfs_readpage, + .prepare_write = unionfs_prepare_write, + .commit_write = unionfs_commit_write, + .bmap = unionfs_bmap, +}; diff -puN /dev/null fs/unionfs/rdstate.c --- /dev/null +++ a/fs/unionfs/rdstate.c @@ -0,0 +1,285 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* This file contains the routines for maintaining readdir state. */ + +/* + * There are two structures here, rdstate which is a hash table + * of the second structure which is a filldir_node. + */ + +/* + * This is a struct kmem_cache for filldir nodes, because we allocate a lot + * of them and they shouldn't waste memory. If the node has a small name + * (as defined by the dentry structure), then we use an inline name to + * preserve kmalloc space. + */ +static struct kmem_cache *unionfs_filldir_cachep; + +int unionfs_init_filldir_cache(void) +{ + unionfs_filldir_cachep = + kmem_cache_create("unionfs_filldir", + sizeof(struct filldir_node), 0, + SLAB_RECLAIM_ACCOUNT, NULL); + + return (unionfs_filldir_cachep ? 0 : -ENOMEM); +} + +void unionfs_destroy_filldir_cache(void) +{ + if (unionfs_filldir_cachep) + kmem_cache_destroy(unionfs_filldir_cachep); +} + +/* + * This is a tuning parameter that tells us roughly how big to make the + * hash table in directory entries per page. This isn't perfect, but + * at least we get a hash table size that shouldn't be too overloaded. + * The following averages are based on my home directory. + * 14.44693 Overall + * 12.29 Single Page Directories + * 117.93 Multi-page directories + */ +#define DENTPAGE 4096 +#define DENTPERONEPAGE 12 +#define DENTPERPAGE 118 +#define MINHASHSIZE 1 +static int guesstimate_hash_size(struct inode *inode) +{ + struct inode *lower_inode; + int bindex; + int hashsize = MINHASHSIZE; + + if (UNIONFS_I(inode)->hashsize > 0) + return UNIONFS_I(inode)->hashsize; + + for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (!lower_inode) + continue; + + if (i_size_read(lower_inode) == DENTPAGE) + hashsize += DENTPERONEPAGE; + else + hashsize += (i_size_read(lower_inode) / DENTPAGE) * + DENTPERPAGE; + } + + return hashsize; +} + +int init_rdstate(struct file *file) +{ + BUG_ON(sizeof(loff_t) != + (sizeof(unsigned int) + sizeof(unsigned int))); + BUG_ON(UNIONFS_F(file)->rdstate != NULL); + + UNIONFS_F(file)->rdstate = alloc_rdstate(file->f_path.dentry->d_inode, + fbstart(file)); + + return (UNIONFS_F(file)->rdstate ? 0 : -ENOMEM); +} + +struct unionfs_dir_state *find_rdstate(struct inode *inode, loff_t fpos) +{ + struct unionfs_dir_state *rdstate = NULL; + struct list_head *pos; + + spin_lock(&UNIONFS_I(inode)->rdlock); + list_for_each(pos, &UNIONFS_I(inode)->readdircache) { + struct unionfs_dir_state *r = + list_entry(pos, struct unionfs_dir_state, cache); + if (fpos == rdstate2offset(r)) { + UNIONFS_I(inode)->rdcount--; + list_del(&r->cache); + rdstate = r; + break; + } + } + spin_unlock(&UNIONFS_I(inode)->rdlock); + return rdstate; +} + +struct unionfs_dir_state *alloc_rdstate(struct inode *inode, int bindex) +{ + int i = 0; + int hashsize; + unsigned long mallocsize = sizeof(struct unionfs_dir_state); + struct unionfs_dir_state *rdstate; + + hashsize = guesstimate_hash_size(inode); + mallocsize += hashsize * sizeof(struct list_head); + mallocsize = __roundup_pow_of_two(mallocsize); + + /* This should give us about 500 entries anyway. */ + if (mallocsize > PAGE_SIZE) + mallocsize = PAGE_SIZE; + + hashsize = (mallocsize - sizeof(struct unionfs_dir_state)) / + sizeof(struct list_head); + + rdstate = kmalloc(mallocsize, GFP_KERNEL); + if (unlikely(!rdstate)) + return NULL; + + spin_lock(&UNIONFS_I(inode)->rdlock); + if (UNIONFS_I(inode)->cookie >= (MAXRDCOOKIE - 1)) + UNIONFS_I(inode)->cookie = 1; + else + UNIONFS_I(inode)->cookie++; + + rdstate->cookie = UNIONFS_I(inode)->cookie; + spin_unlock(&UNIONFS_I(inode)->rdlock); + rdstate->offset = 1; + rdstate->access = jiffies; + rdstate->bindex = bindex; + rdstate->dirpos = 0; + rdstate->hashentries = 0; + rdstate->size = hashsize; + for (i = 0; i < rdstate->size; i++) + INIT_LIST_HEAD(&rdstate->list[i]); + + return rdstate; +} + +static void free_filldir_node(struct filldir_node *node) +{ + if (node->namelen >= DNAME_INLINE_LEN_MIN) + kfree(node->name); + kmem_cache_free(unionfs_filldir_cachep, node); +} + +void free_rdstate(struct unionfs_dir_state *state) +{ + struct filldir_node *tmp; + int i; + + for (i = 0; i < state->size; i++) { + struct list_head *head = &(state->list[i]); + struct list_head *pos, *n; + + /* traverse the list and deallocate space */ + list_for_each_safe(pos, n, head) { + tmp = list_entry(pos, struct filldir_node, file_list); + list_del(&tmp->file_list); + free_filldir_node(tmp); + } + } + + kfree(state); +} + +struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate, + const char *name, int namelen, + int is_whiteout) +{ + int index; + unsigned int hash; + struct list_head *head; + struct list_head *pos; + struct filldir_node *cursor = NULL; + int found = 0; + + BUG_ON(namelen <= 0); + + hash = full_name_hash(name, namelen); + index = hash % rdstate->size; + + head = &(rdstate->list[index]); + list_for_each(pos, head) { + cursor = list_entry(pos, struct filldir_node, file_list); + + if (cursor->namelen == namelen && cursor->hash == hash && + !strncmp(cursor->name, name, namelen)) { + /* + * a duplicate exists, and hence no need to create + * entry to the list + */ + found = 1; + + /* + * if a duplicate is found in this branch, and is + * not due to the caller looking for an entry to + * whiteout, then the file system may be corrupted. + */ + if (unlikely(!is_whiteout && + cursor->bindex == rdstate->bindex)) + printk(KERN_ERR "unionfs: filldir: possible " + "I/O error: a file is duplicated " + "in the same branch %d: %s\n", + rdstate->bindex, cursor->name); + break; + } + } + + if (!found) + cursor = NULL; + + return cursor; +} + +int add_filldir_node(struct unionfs_dir_state *rdstate, const char *name, + int namelen, int bindex, int whiteout) +{ + struct filldir_node *new; + unsigned int hash; + int index; + int err = 0; + struct list_head *head; + + BUG_ON(namelen <= 0); + + hash = full_name_hash(name, namelen); + index = hash % rdstate->size; + head = &(rdstate->list[index]); + + new = kmem_cache_alloc(unionfs_filldir_cachep, GFP_KERNEL); + if (unlikely(!new)) { + err = -ENOMEM; + goto out; + } + + INIT_LIST_HEAD(&new->file_list); + new->namelen = namelen; + new->hash = hash; + new->bindex = bindex; + new->whiteout = whiteout; + + if (namelen < DNAME_INLINE_LEN_MIN) { + new->name = new->iname; + } else { + new->name = kmalloc(namelen + 1, GFP_KERNEL); + if (unlikely(!new->name)) { + kmem_cache_free(unionfs_filldir_cachep, new); + new = NULL; + goto out; + } + } + + memcpy(new->name, name, namelen); + new->name[namelen] = '\0'; + + rdstate->hashentries++; + + list_add(&(new->file_list), head); +out: + return err; +} diff -puN /dev/null fs/unionfs/rename.c --- /dev/null +++ a/fs/unionfs/rename.c @@ -0,0 +1,533 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +static int __unionfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + int bindex, struct dentry **wh_old) +{ + int err = 0; + struct dentry *lower_old_dentry; + struct dentry *lower_new_dentry; + struct dentry *lower_old_dir_dentry; + struct dentry *lower_new_dir_dentry; + struct dentry *lower_wh_dentry; + struct dentry *lower_wh_dir_dentry; + char *wh_name = NULL; + + lower_new_dentry = unionfs_lower_dentry_idx(new_dentry, bindex); + lower_old_dentry = unionfs_lower_dentry_idx(old_dentry, bindex); + + if (!lower_new_dentry) { + lower_new_dentry = + create_parents(new_dentry->d_parent->d_inode, + new_dentry, new_dentry->d_name.name, + bindex); + if (IS_ERR(lower_new_dentry)) { + err = PTR_ERR(lower_new_dentry); + if (IS_COPYUP_ERR(err)) + goto out; + printk(KERN_ERR "unionfs: error creating directory " + "tree for rename, bindex=%d err=%d\n", + bindex, err); + goto out; + } + } + + wh_name = alloc_whname(new_dentry->d_name.name, + new_dentry->d_name.len); + if (unlikely(IS_ERR(wh_name))) { + err = PTR_ERR(wh_name); + goto out; + } + + lower_wh_dentry = lookup_one_len(wh_name, lower_new_dentry->d_parent, + new_dentry->d_name.len + + UNIONFS_WHLEN); + if (IS_ERR(lower_wh_dentry)) { + err = PTR_ERR(lower_wh_dentry); + goto out; + } + + if (lower_wh_dentry->d_inode) { + /* get rid of the whiteout that is existing */ + if (lower_new_dentry->d_inode) { + printk(KERN_ERR "unionfs: both a whiteout and a " + "dentry exist when doing a rename!\n"); + err = -EIO; + + dput(lower_wh_dentry); + goto out; + } + + lower_wh_dir_dentry = lock_parent(lower_wh_dentry); + err = is_robranch_super(old_dentry->d_sb, bindex); + if (!err) + err = vfs_unlink(lower_wh_dir_dentry->d_inode, + lower_wh_dentry); + + dput(lower_wh_dentry); + unlock_dir(lower_wh_dir_dentry); + if (err) + goto out; + } else { + dput(lower_wh_dentry); + } + + dget(lower_old_dentry); + lower_old_dir_dentry = dget_parent(lower_old_dentry); + lower_new_dir_dentry = dget_parent(lower_new_dentry); + + lock_rename(lower_old_dir_dentry, lower_new_dir_dentry); + + err = is_robranch_super(old_dentry->d_sb, bindex); + if (err) + goto out_unlock; + + /* + * ready to whiteout for old_dentry. caller will create the actual + * whiteout, and must dput(*wh_old) + */ + if (wh_old) { + char *whname; + whname = alloc_whname(old_dentry->d_name.name, + old_dentry->d_name.len); + err = PTR_ERR(whname); + if (unlikely(IS_ERR(whname))) + goto out_unlock; + *wh_old = lookup_one_len(whname, lower_old_dir_dentry, + old_dentry->d_name.len + + UNIONFS_WHLEN); + kfree(whname); + err = PTR_ERR(*wh_old); + if (IS_ERR(*wh_old)) { + *wh_old = NULL; + goto out_unlock; + } + } + + err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry, + lower_new_dir_dentry->d_inode, lower_new_dentry); + +out_unlock: + unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry); + + dput(lower_old_dir_dentry); + dput(lower_new_dir_dentry); + dput(lower_old_dentry); + +out: + if (!err) { + /* Fixup the new_dentry. */ + if (bindex < dbstart(new_dentry)) + set_dbstart(new_dentry, bindex); + else if (bindex > dbend(new_dentry)) + set_dbend(new_dentry, bindex); + } + + kfree(wh_name); + + return err; +} + +/* + * Main rename code. This is sufficiently complex, that it's documented in + * Documentation/filesystems/unionfs/rename.txt. This routine calls + * __unionfs_rename() above to perform some of the work. + */ +static int do_unionfs_rename(struct inode *old_dir, + struct dentry *old_dentry, + struct inode *new_dir, + struct dentry *new_dentry) +{ + int err = 0; + int bindex, bwh_old; + int old_bstart, old_bend; + int new_bstart, new_bend; + int do_copyup = -1; + struct dentry *parent_dentry; + int local_err = 0; + int eio = 0; + int revert = 0; + struct dentry *wh_old = NULL; + + old_bstart = dbstart(old_dentry); + bwh_old = old_bstart; + old_bend = dbend(old_dentry); + parent_dentry = old_dentry->d_parent; + + new_bstart = dbstart(new_dentry); + new_bend = dbend(new_dentry); + + /* Rename source to destination. */ + err = __unionfs_rename(old_dir, old_dentry, new_dir, new_dentry, + old_bstart, &wh_old); + if (err) { + if (!IS_COPYUP_ERR(err)) + goto out; + do_copyup = old_bstart - 1; + } else { + revert = 1; + } + + /* + * Unlink all instances of destination that exist to the left of + * bstart of source. On error, revert back, goto out. + */ + for (bindex = old_bstart - 1; bindex >= new_bstart; bindex--) { + struct dentry *unlink_dentry; + struct dentry *unlink_dir_dentry; + + unlink_dentry = unionfs_lower_dentry_idx(new_dentry, bindex); + if (!unlink_dentry) + continue; + + unlink_dir_dentry = lock_parent(unlink_dentry); + err = is_robranch_super(old_dir->i_sb, bindex); + if (!err) + err = vfs_unlink(unlink_dir_dentry->d_inode, + unlink_dentry); + + fsstack_copy_attr_times(new_dentry->d_parent->d_inode, + unlink_dir_dentry->d_inode); + /* propagate number of hard-links */ + new_dentry->d_parent->d_inode->i_nlink = + unionfs_get_nlinks(new_dentry->d_parent->d_inode); + + unlock_dir(unlink_dir_dentry); + if (!err) { + if (bindex != new_bstart) { + dput(unlink_dentry); + unionfs_set_lower_dentry_idx(new_dentry, + bindex, NULL); + } + } else if (IS_COPYUP_ERR(err)) { + do_copyup = bindex - 1; + } else if (revert) { + dput(wh_old); + goto revert; + } + } + + if (do_copyup != -1) { + for (bindex = do_copyup; bindex >= 0; bindex--) { + /* + * copyup the file into some left directory, so that + * you can rename it + */ + err = copyup_dentry(old_dentry->d_parent->d_inode, + old_dentry, old_bstart, bindex, + old_dentry->d_name.name, + old_dentry->d_name.len, NULL, + i_size_read(old_dentry->d_inode)); + /* if copyup failed, try next branch to the left */ + if (err) + continue; + dput(wh_old); + bwh_old = bindex; + err = __unionfs_rename(old_dir, old_dentry, + new_dir, new_dentry, + bindex, &wh_old); + break; + } + } + + /* make it opaque */ + if (S_ISDIR(old_dentry->d_inode->i_mode)) { + err = make_dir_opaque(old_dentry, dbstart(old_dentry)); + if (err) + goto revert; + } + + /* + * Create whiteout for source, only if: + * (1) There is more than one underlying instance of source. + * (2) We did a copy_up + */ + if ((old_bstart != old_bend) || (do_copyup != -1)) { + struct dentry *lower_parent; + struct nameidata nd; + if (!wh_old || wh_old->d_inode || bwh_old < 0) { + printk(KERN_ERR "unionfs: rename error " + "(wh_old=%p/%p bwh_old=%d)\n", wh_old, + (wh_old ? wh_old->d_inode : NULL), bwh_old); + err = -EIO; + goto out; + } + err = init_lower_nd(&nd, LOOKUP_CREATE); + if (unlikely(err < 0)) + goto out; + lower_parent = lock_parent(wh_old); + local_err = vfs_create(lower_parent->d_inode, wh_old, S_IRUGO, + &nd); + unlock_dir(lower_parent); + if (!local_err) { + set_dbopaque(old_dentry, bwh_old); + } else { + /* + * we can't fix anything now, so we cop-out and use + * -EIO. + */ + printk(KERN_ERR "unionfs: can't create a whiteout for " + "the source in rename!\n"); + err = -EIO; + } + release_lower_nd(&nd, local_err); + } + +out: + dput(wh_old); + return err; + +revert: + /* Do revert here. */ + local_err = unionfs_refresh_lower_dentry(new_dentry, old_bstart); + if (local_err) { + printk(KERN_ERR "unionfs: revert failed in rename: " + "the new refresh failed\n"); + eio = -EIO; + } + + local_err = unionfs_refresh_lower_dentry(old_dentry, old_bstart); + if (local_err) { + printk(KERN_ERR "unionfs: revert failed in rename: " + "the old refresh failed\n"); + eio = -EIO; + goto revert_out; + } + + if (!unionfs_lower_dentry_idx(new_dentry, bindex) || + !unionfs_lower_dentry_idx(new_dentry, bindex)->d_inode) { + printk(KERN_ERR "unionfs: revert failed in rename: " + "the object disappeared from under us!\n"); + eio = -EIO; + goto revert_out; + } + + if (unionfs_lower_dentry_idx(old_dentry, bindex) && + unionfs_lower_dentry_idx(old_dentry, bindex)->d_inode) { + printk(KERN_ERR "unionfs: revert failed in rename: " + "the object was created underneath us!\n"); + eio = -EIO; + goto revert_out; + } + + local_err = __unionfs_rename(new_dir, new_dentry, + old_dir, old_dentry, old_bstart, NULL); + + /* If we can't fix it, then we cop-out with -EIO. */ + if (local_err) { + printk(KERN_ERR "unionfs: revert failed in rename!\n"); + eio = -EIO; + } + + local_err = unionfs_refresh_lower_dentry(new_dentry, bindex); + if (local_err) + eio = -EIO; + local_err = unionfs_refresh_lower_dentry(old_dentry, bindex); + if (local_err) + eio = -EIO; + +revert_out: + if (eio) + err = eio; + return err; +} + +static struct dentry *lookup_whiteout(struct dentry *dentry) +{ + char *whname; + int bindex = -1, bstart = -1, bend = -1; + struct dentry *parent, *lower_parent, *wh_dentry; + + whname = alloc_whname(dentry->d_name.name, dentry->d_name.len); + if (unlikely(IS_ERR(whname))) + return (void *)whname; + + parent = dget_parent(dentry); + unionfs_lock_dentry(parent); + bstart = dbstart(parent); + bend = dbend(parent); + wh_dentry = ERR_PTR(-ENOENT); + for (bindex = bstart; bindex <= bend; bindex++) { + lower_parent = unionfs_lower_dentry_idx(parent, bindex); + if (!lower_parent) + continue; + wh_dentry = lookup_one_len(whname, lower_parent, + dentry->d_name.len + UNIONFS_WHLEN); + if (IS_ERR(wh_dentry)) + continue; + if (wh_dentry->d_inode) + break; + dput(wh_dentry); + wh_dentry = ERR_PTR(-ENOENT); + } + unionfs_unlock_dentry(parent); + dput(parent); + kfree(whname); + return wh_dentry; +} + +/* + * We can't copyup a directory, because it may involve huge numbers of + * children, etc. Doing that in the kernel would be bad, so instead we + * return EXDEV to the user-space utility that caused this, and let the + * user-space recurse and ask us to copy up each file separately. + */ +static int may_rename_dir(struct dentry *dentry) +{ + int err, bstart; + + err = check_empty(dentry, NULL); + if (err == -ENOTEMPTY) { + if (is_robranch(dentry)) + return -EXDEV; + } else if (err) { + return err; + } + + bstart = dbstart(dentry); + if (dbend(dentry) == bstart || dbopaque(dentry) == bstart) + return 0; + + set_dbstart(dentry, bstart + 1); + err = check_empty(dentry, NULL); + set_dbstart(dentry, bstart); + if (err == -ENOTEMPTY) + err = -EXDEV; + return err; +} + +int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + int err = 0; + struct dentry *wh_dentry; + + unionfs_read_lock(old_dentry->d_sb); + unionfs_double_lock_dentry(old_dentry, new_dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(old_dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + if (unlikely(!d_deleted(new_dentry) && new_dentry->d_inode && + !__unionfs_d_revalidate_chain(new_dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + if (!S_ISDIR(old_dentry->d_inode->i_mode)) + err = unionfs_partial_lookup(old_dentry); + else + err = may_rename_dir(old_dentry); + + if (err) + goto out; + + err = unionfs_partial_lookup(new_dentry); + if (err) + goto out; + + /* + * if new_dentry is already lower because of whiteout, + * simply override it even if the whited-out dir is not empty. + */ + wh_dentry = lookup_whiteout(new_dentry); + if (!IS_ERR(wh_dentry)) { + dput(wh_dentry); + } else if (new_dentry->d_inode) { + if (S_ISDIR(old_dentry->d_inode->i_mode) != + S_ISDIR(new_dentry->d_inode->i_mode)) { + err = S_ISDIR(old_dentry->d_inode->i_mode) ? + -ENOTDIR : -EISDIR; + goto out; + } + + if (S_ISDIR(new_dentry->d_inode->i_mode)) { + struct unionfs_dir_state *namelist; + /* check if this unionfs directory is empty or not */ + err = check_empty(new_dentry, &namelist); + if (err) + goto out; + + if (!is_robranch(new_dentry)) + err = delete_whiteouts(new_dentry, + dbstart(new_dentry), + namelist); + + free_rdstate(namelist); + + if (err) + goto out; + } + } + err = do_unionfs_rename(old_dir, old_dentry, new_dir, new_dentry); +out: + if (err) { + /* clear the new_dentry stuff created */ + d_drop(new_dentry); + } else { + /* + * force re-lookup since the dir on ro branch is not renamed, + * and lower dentries still indicate the un-renamed ones. + */ + if (S_ISDIR(old_dentry->d_inode->i_mode)) + atomic_dec(&UNIONFS_D(old_dentry)->generation); + else + unionfs_postcopyup_release(old_dentry); + if (new_dentry->d_inode && + !S_ISDIR(new_dentry->d_inode->i_mode)) { + unionfs_postcopyup_release(new_dentry); + unionfs_postcopyup_setmnt(new_dentry); + if (!unionfs_lower_inode(new_dentry->d_inode)) { + /* + * If we get here, it means that no copyup + * was needed, and that a file by the old + * name already existing on the destination + * branch; that file got renamed earlier in + * this function, so all we need to do here + * is set the lower inode. + */ + struct inode *inode; + inode = unionfs_lower_inode( + old_dentry->d_inode); + igrab(inode); + unionfs_set_lower_inode_idx( + new_dentry->d_inode, + dbstart(new_dentry), inode); + } + + } + /* if all of this renaming succeeded, update our times */ + unionfs_copy_attr_times(old_dir); + unionfs_copy_attr_times(new_dir); + unionfs_copy_attr_times(old_dentry->d_inode); + unionfs_copy_attr_times(new_dentry->d_inode); + unionfs_check_inode(old_dir); + unionfs_check_inode(new_dir); + unionfs_check_dentry(old_dentry); + unionfs_check_dentry(new_dentry); + } + + unionfs_unlock_dentry(new_dentry); + unionfs_unlock_dentry(old_dentry); + unionfs_read_unlock(old_dentry->d_sb); + return err; +} diff -puN /dev/null fs/unionfs/sioq.c --- /dev/null +++ a/fs/unionfs/sioq.c @@ -0,0 +1,119 @@ +/* + * Copyright (c) 2006-2007 Erez Zadok + * Copyright (c) 2006 Charles P. Wright + * Copyright (c) 2006-2007 Josef 'Jeff' Sipek + * Copyright (c) 2006 Junjiro Okajima + * Copyright (c) 2006 David P. Quigley + * Copyright (c) 2006-2007 Stony Brook University + * Copyright (c) 2006-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * Super-user IO work Queue - sometimes we need to perform actions which + * would fail due to the unix permissions on the parent directory (e.g., + * rmdir a directory which appears empty, but in reality contains + * whiteouts). + */ + +static struct workqueue_struct *superio_workqueue; + +int __init init_sioq(void) +{ + int err; + + superio_workqueue = create_workqueue("unionfs_siod"); + if (!IS_ERR(superio_workqueue)) + return 0; + + err = PTR_ERR(superio_workqueue); + printk(KERN_ERR "unionfs: create_workqueue failed %d\n", err); + superio_workqueue = NULL; + return err; +} + +void stop_sioq(void) +{ + if (superio_workqueue) + destroy_workqueue(superio_workqueue); +} + +void run_sioq(work_func_t func, struct sioq_args *args) +{ + INIT_WORK(&args->work, func); + + init_completion(&args->comp); + while (!queue_work(superio_workqueue, &args->work)) { + /* TODO: do accounting if needed */ + schedule(); + } + wait_for_completion(&args->comp); +} + +void __unionfs_create(struct work_struct *work) +{ + struct sioq_args *args = container_of(work, struct sioq_args, work); + struct create_args *c = &args->create; + + args->err = vfs_create(c->parent, c->dentry, c->mode, c->nd); + complete(&args->comp); +} + +void __unionfs_mkdir(struct work_struct *work) +{ + struct sioq_args *args = container_of(work, struct sioq_args, work); + struct mkdir_args *m = &args->mkdir; + + args->err = vfs_mkdir(m->parent, m->dentry, m->mode); + complete(&args->comp); +} + +void __unionfs_mknod(struct work_struct *work) +{ + struct sioq_args *args = container_of(work, struct sioq_args, work); + struct mknod_args *m = &args->mknod; + + args->err = vfs_mknod(m->parent, m->dentry, m->mode, m->dev); + complete(&args->comp); +} + +void __unionfs_symlink(struct work_struct *work) +{ + struct sioq_args *args = container_of(work, struct sioq_args, work); + struct symlink_args *s = &args->symlink; + + args->err = vfs_symlink(s->parent, s->dentry, s->symbuf, s->mode); + complete(&args->comp); +} + +void __unionfs_unlink(struct work_struct *work) +{ + struct sioq_args *args = container_of(work, struct sioq_args, work); + struct unlink_args *u = &args->unlink; + + args->err = vfs_unlink(u->parent, u->dentry); + complete(&args->comp); +} + +void __delete_whiteouts(struct work_struct *work) +{ + struct sioq_args *args = container_of(work, struct sioq_args, work); + struct deletewh_args *d = &args->deletewh; + + args->err = do_delete_whiteouts(d->dentry, d->bindex, d->namelist); + complete(&args->comp); +} + +void __is_opaque_dir(struct work_struct *work) +{ + struct sioq_args *args = container_of(work, struct sioq_args, work); + + args->ret = lookup_one_len(UNIONFS_DIR_OPAQUE, args->is_opaque.dentry, + sizeof(UNIONFS_DIR_OPAQUE) - 1); + complete(&args->comp); +} diff -puN /dev/null fs/unionfs/sioq.h --- /dev/null +++ a/fs/unionfs/sioq.h @@ -0,0 +1,92 @@ +/* + * Copyright (c) 2006-2007 Erez Zadok + * Copyright (c) 2006 Charles P. Wright + * Copyright (c) 2006-2007 Josef 'Jeff' Sipek + * Copyright (c) 2006 Junjiro Okajima + * Copyright (c) 2006 David P. Quigley + * Copyright (c) 2006-2007 Stony Brook University + * Copyright (c) 2006-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _SIOQ_H +#define _SIOQ_H + +struct deletewh_args { + struct unionfs_dir_state *namelist; + struct dentry *dentry; + int bindex; +}; + +struct is_opaque_args { + struct dentry *dentry; +}; + +struct create_args { + struct inode *parent; + struct dentry *dentry; + umode_t mode; + struct nameidata *nd; +}; + +struct mkdir_args { + struct inode *parent; + struct dentry *dentry; + umode_t mode; +}; + +struct mknod_args { + struct inode *parent; + struct dentry *dentry; + umode_t mode; + dev_t dev; +}; + +struct symlink_args { + struct inode *parent; + struct dentry *dentry; + char *symbuf; + umode_t mode; +}; + +struct unlink_args { + struct inode *parent; + struct dentry *dentry; +}; + + +struct sioq_args { + struct completion comp; + struct work_struct work; + int err; + void *ret; + + union { + struct deletewh_args deletewh; + struct is_opaque_args is_opaque; + struct create_args create; + struct mkdir_args mkdir; + struct mknod_args mknod; + struct symlink_args symlink; + struct unlink_args unlink; + }; +}; + +/* Extern definitions for SIOQ functions */ +extern int __init init_sioq(void); +extern void stop_sioq(void); +extern void run_sioq(work_func_t func, struct sioq_args *args); + +/* Extern definitions for our privilege escalation helpers */ +extern void __unionfs_create(struct work_struct *work); +extern void __unionfs_mkdir(struct work_struct *work); +extern void __unionfs_mknod(struct work_struct *work); +extern void __unionfs_symlink(struct work_struct *work); +extern void __unionfs_unlink(struct work_struct *work); +extern void __delete_whiteouts(struct work_struct *work); +extern void __is_opaque_dir(struct work_struct *work); + +#endif /* not _SIOQ_H */ diff -puN /dev/null fs/unionfs/subr.c --- /dev/null +++ a/fs/unionfs/subr.c @@ -0,0 +1,242 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * Pass an unionfs dentry and an index. It will try to create a whiteout + * for the filename in dentry, and will try in branch 'index'. On error, + * it will proceed to a branch to the left. + */ +int create_whiteout(struct dentry *dentry, int start) +{ + int bstart, bend, bindex; + struct dentry *lower_dir_dentry; + struct dentry *lower_dentry; + struct dentry *lower_wh_dentry; + struct nameidata nd; + char *name = NULL; + int err = -EINVAL; + + verify_locked(dentry); + + bstart = dbstart(dentry); + bend = dbend(dentry); + + /* create dentry's whiteout equivalent */ + name = alloc_whname(dentry->d_name.name, dentry->d_name.len); + if (unlikely(IS_ERR(name))) { + err = PTR_ERR(name); + goto out; + } + + for (bindex = start; bindex >= 0; bindex--) { + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + + if (!lower_dentry) { + /* + * if lower dentry is not present, create the + * entire lower dentry directory structure and go + * ahead. Since we want to just create whiteout, we + * only want the parent dentry, and hence get rid of + * this dentry. + */ + lower_dentry = create_parents(dentry->d_inode, + dentry, + dentry->d_name.name, + bindex); + if (!lower_dentry || IS_ERR(lower_dentry)) { + int ret = PTR_ERR(lower_dentry); + if (!IS_COPYUP_ERR(ret)) + printk(KERN_ERR + "unionfs: create_parents for " + "whiteout failed: bindex=%d " + "err=%d\n", bindex, ret); + continue; + } + } + + lower_wh_dentry = + lookup_one_len(name, lower_dentry->d_parent, + dentry->d_name.len + UNIONFS_WHLEN); + if (IS_ERR(lower_wh_dentry)) + continue; + + /* + * The whiteout already exists. This used to be impossible, + * but now is possible because of opaqueness. + */ + if (lower_wh_dentry->d_inode) { + dput(lower_wh_dentry); + err = 0; + goto out; + } + + err = init_lower_nd(&nd, LOOKUP_CREATE); + if (unlikely(err < 0)) + goto out; + lower_dir_dentry = lock_parent(lower_wh_dentry); + err = is_robranch_super(dentry->d_sb, bindex); + if (!err) + err = vfs_create(lower_dir_dentry->d_inode, + lower_wh_dentry, + ~current->fs->umask & S_IRWXUGO, + &nd); + unlock_dir(lower_dir_dentry); + dput(lower_wh_dentry); + release_lower_nd(&nd, err); + + if (!err || !IS_COPYUP_ERR(err)) + break; + } + + /* set dbopaque so that lookup will not proceed after this branch */ + if (!err) + set_dbopaque(dentry, bindex); + +out: + kfree(name); + return err; +} + +/* + * This is a helper function for rename, which ends up with hosed over + * dentries when it needs to revert. + */ +int unionfs_refresh_lower_dentry(struct dentry *dentry, int bindex) +{ + struct dentry *lower_dentry; + struct dentry *lower_parent; + int err = 0; + + verify_locked(dentry); + + unionfs_lock_dentry(dentry->d_parent); + lower_parent = unionfs_lower_dentry_idx(dentry->d_parent, bindex); + unionfs_unlock_dentry(dentry->d_parent); + + BUG_ON(!S_ISDIR(lower_parent->d_inode->i_mode)); + + lower_dentry = lookup_one_len(dentry->d_name.name, lower_parent, + dentry->d_name.len); + if (IS_ERR(lower_dentry)) { + err = PTR_ERR(lower_dentry); + goto out; + } + + dput(unionfs_lower_dentry_idx(dentry, bindex)); + iput(unionfs_lower_inode_idx(dentry->d_inode, bindex)); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, NULL); + + if (!lower_dentry->d_inode) { + dput(lower_dentry); + unionfs_set_lower_dentry_idx(dentry, bindex, NULL); + } else { + unionfs_set_lower_dentry_idx(dentry, bindex, lower_dentry); + unionfs_set_lower_inode_idx(dentry->d_inode, bindex, + igrab(lower_dentry->d_inode)); + } + +out: + return err; +} + +int make_dir_opaque(struct dentry *dentry, int bindex) +{ + int err = 0; + struct dentry *lower_dentry, *diropq; + struct inode *lower_dir; + struct nameidata nd; + kernel_cap_t orig_cap; + + /* + * Opaque directory whiteout markers are special files (like regular + * whiteouts), and should appear to the users as if they don't + * exist. They should be created/deleted regardless of directory + * search/create permissions, but only for the duration of this + * creation of the .wh.__dir_opaque: file. Note, this does not + * circumvent normal ->permission). + */ + orig_cap = current->cap_effective; + cap_raise(current->cap_effective, CAP_DAC_READ_SEARCH); + cap_raise(current->cap_effective, CAP_DAC_OVERRIDE); + + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + lower_dir = lower_dentry->d_inode; + BUG_ON(!S_ISDIR(dentry->d_inode->i_mode) || + !S_ISDIR(lower_dir->i_mode)); + + mutex_lock(&lower_dir->i_mutex); + diropq = lookup_one_len(UNIONFS_DIR_OPAQUE, lower_dentry, + sizeof(UNIONFS_DIR_OPAQUE) - 1); + if (IS_ERR(diropq)) { + err = PTR_ERR(diropq); + goto out; + } + + err = init_lower_nd(&nd, LOOKUP_CREATE); + if (unlikely(err < 0)) + goto out; + if (!diropq->d_inode) + err = vfs_create(lower_dir, diropq, S_IRUGO, &nd); + if (!err) + set_dbopaque(dentry, bindex); + release_lower_nd(&nd, err); + + dput(diropq); + +out: + mutex_unlock(&lower_dir->i_mutex); + current->cap_effective = orig_cap; + return err; +} + +/* + * returns the right n_link value based on the inode type + */ +int unionfs_get_nlinks(const struct inode *inode) +{ + /* don't bother to do all the work since we're unlinked */ + if (inode->i_nlink == 0) + return 0; + + if (!S_ISDIR(inode->i_mode)) + return unionfs_lower_inode(inode)->i_nlink; + + /* + * For directories, we return 1. The only place that could cares + * about links is readdir, and there's d_type there so even that + * doesn't matter. + */ + return 1; +} + +/* construct whiteout filename */ +char *alloc_whname(const char *name, int len) +{ + char *buf; + + buf = kmalloc(len + UNIONFS_WHLEN + 1, GFP_KERNEL); + if (unlikely(!buf)) + return ERR_PTR(-ENOMEM); + + strcpy(buf, UNIONFS_WHPFX); + strlcat(buf, name, len + UNIONFS_WHLEN + 1); + + return buf; +} diff -puN /dev/null fs/unionfs/super.c --- /dev/null +++ a/fs/unionfs/super.c @@ -0,0 +1,1010 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* + * The inode cache is used with alloc_inode for both our inode info and the + * vfs inode. + */ +static struct kmem_cache *unionfs_inode_cachep; + +static void unionfs_read_inode(struct inode *inode) +{ + int size; + struct unionfs_inode_info *info = UNIONFS_I(inode); + + unionfs_read_lock(inode->i_sb); + + memset(info, 0, offsetof(struct unionfs_inode_info, vfs_inode)); + info->bstart = -1; + info->bend = -1; + atomic_set(&info->generation, + atomic_read(&UNIONFS_SB(inode->i_sb)->generation)); + spin_lock_init(&info->rdlock); + info->rdcount = 1; + info->hashsize = -1; + INIT_LIST_HEAD(&info->readdircache); + + size = sbmax(inode->i_sb) * sizeof(struct inode *); + info->lower_inodes = kzalloc(size, GFP_KERNEL); + if (unlikely(!info->lower_inodes)) { + printk(KERN_CRIT "unionfs: no kernel memory when allocating " + "lower-pointer array!\n"); + BUG(); + } + + inode->i_version++; + inode->i_op = &unionfs_main_iops; + inode->i_fop = &unionfs_main_fops; + + inode->i_mapping->a_ops = &unionfs_aops; + + unionfs_read_unlock(inode->i_sb); +} + +/* + * we now define delete_inode, because there are two VFS paths that may + * destroy an inode: one of them calls clear inode before doing everything + * else that's needed, and the other is fine. This way we truncate the inode + * size (and its pages) and then clear our own inode, which will do an iput + * on our and the lower inode. + * + * No need to lock sb info's rwsem. + */ +static void unionfs_delete_inode(struct inode *inode) +{ + i_size_write(inode, 0); /* every f/s seems to do that */ + + if (inode->i_data.nrpages) + truncate_inode_pages(&inode->i_data, 0); + + clear_inode(inode); +} + +/* + * final actions when unmounting a file system + * + * No need to lock rwsem. + */ +static void unionfs_put_super(struct super_block *sb) +{ + int bindex, bstart, bend; + struct unionfs_sb_info *spd; + int leaks = 0; + + spd = UNIONFS_SB(sb); + if (!spd) + return; + + bstart = sbstart(sb); + bend = sbend(sb); + + /* Make sure we have no leaks of branchget/branchput. */ + for (bindex = bstart; bindex <= bend; bindex++) + if (unlikely(branch_count(sb, bindex) != 0)) { + printk(KERN_CRIT + "unionfs: branch %d has %d references left!\n", + bindex, branch_count(sb, bindex)); + leaks = 1; + } + BUG_ON(leaks != 0); + + kfree(spd->data); + kfree(spd); + sb->s_fs_info = NULL; +} + +/* + * Since people use this to answer the "How big of a file can I write?" + * question, we report the size of the highest priority branch as the size of + * the union. + */ +static int unionfs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + int err = 0; + struct super_block *sb; + struct dentry *lower_dentry; + + sb = dentry->d_sb; + + unionfs_read_lock(sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + unionfs_check_dentry(dentry); + + lower_dentry = unionfs_lower_dentry(sb->s_root); + err = vfs_statfs(lower_dentry, buf); + + /* set return buf to our f/s to avoid confusing user-level utils */ + buf->f_type = UNIONFS_SUPER_MAGIC; + /* + * Our maximum file name can is shorter by a few bytes because every + * file name could potentially be whited-out. + * + * XXX: this restriction goes away with ODF. + */ + buf->f_namelen -= UNIONFS_WHLEN; + + /* + * reset two fields to avoid confusing user-land. + * XXX: is this still necessary? + */ + memset(&buf->f_fsid, 0, sizeof(__kernel_fsid_t)); + memset(&buf->f_spare, 0, sizeof(buf->f_spare)); + +out: + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(sb); + return err; +} + +/* handle mode changing during remount */ +static noinline int do_remount_mode_option(char *optarg, int cur_branches, + struct unionfs_data *new_data, + struct path *new_lower_paths) +{ + int err = -EINVAL; + int perms, idx; + char *modename = strchr(optarg, '='); + struct nameidata nd; + + /* by now, optarg contains the branch name */ + if (!*optarg) { + printk(KERN_ERR + "unionfs: no branch specified for mode change\n"); + goto out; + } + if (!modename) { + printk(KERN_ERR "unionfs: branch \"%s\" requires a mode\n", + optarg); + goto out; + } + *modename++ = '\0'; + err = parse_branch_mode(modename, &perms); + if (err) { + printk(KERN_ERR "unionfs: invalid mode \"%s\" for \"%s\"\n", + modename, optarg); + goto out; + } + + /* + * Find matching branch index. For now, this assumes that nothing + * has been mounted on top of this Unionfs stack. Once we have /odf + * and cache-coherency resolved, we'll address the branch-path + * uniqueness. + */ + err = path_lookup(optarg, LOOKUP_FOLLOW, &nd); + if (err) { + printk(KERN_ERR "unionfs: error accessing " + "lower directory \"%s\" (error %d)\n", + optarg, err); + goto out; + } + for (idx = 0; idx < cur_branches; idx++) + if (nd.mnt == new_lower_paths[idx].mnt && + nd.dentry == new_lower_paths[idx].dentry) + break; + path_release(&nd); /* no longer needed */ + if (idx == cur_branches) { + err = -ENOENT; /* err may have been reset above */ + printk(KERN_ERR "unionfs: branch \"%s\" " + "not found\n", optarg); + goto out; + } + /* check/change mode for existing branch */ + /* we don't warn if perms==branchperms */ + new_data[idx].branchperms = perms; + err = 0; +out: + return err; +} + +/* handle branch deletion during remount */ +static noinline int do_remount_del_option(char *optarg, int cur_branches, + struct unionfs_data *new_data, + struct path *new_lower_paths) +{ + int err = -EINVAL; + int idx; + struct nameidata nd; + + /* optarg contains the branch name to delete */ + + /* + * Find matching branch index. For now, this assumes that nothing + * has been mounted on top of this Unionfs stack. Once we have /odf + * and cache-coherency resolved, we'll address the branch-path + * uniqueness. + */ + err = path_lookup(optarg, LOOKUP_FOLLOW, &nd); + if (err) { + printk(KERN_ERR "unionfs: error accessing " + "lower directory \"%s\" (error %d)\n", + optarg, err); + goto out; + } + for (idx = 0; idx < cur_branches; idx++) + if (nd.mnt == new_lower_paths[idx].mnt && + nd.dentry == new_lower_paths[idx].dentry) + break; + path_release(&nd); /* no longer needed */ + if (idx == cur_branches) { + printk(KERN_ERR "unionfs: branch \"%s\" " + "not found\n", optarg); + err = -ENOENT; + goto out; + } + /* check if there are any open files on the branch to be deleted */ + if (atomic_read(&new_data[idx].open_files) > 0) { + err = -EBUSY; + goto out; + } + + /* + * Now we have to delete the branch. First, release any handles it + * has. Then, move the remaining array indexes past "idx" in + * new_data and new_lower_paths one to the left. Finally, adjust + * cur_branches. + */ + pathput(&new_lower_paths[idx]); + + if (idx < cur_branches - 1) { + /* if idx==cur_branches-1, we delete last branch: easy */ + memmove(&new_data[idx], &new_data[idx+1], + (cur_branches - 1 - idx) * + sizeof(struct unionfs_data)); + memmove(&new_lower_paths[idx], &new_lower_paths[idx+1], + (cur_branches - 1 - idx) * sizeof(struct path)); + } + + err = 0; +out: + return err; +} + +/* handle branch insertion during remount */ +static noinline int do_remount_add_option(char *optarg, int cur_branches, + struct unionfs_data *new_data, + struct path *new_lower_paths, + int *high_branch_id) +{ + int err = -EINVAL; + int perms; + int idx = 0; /* default: insert at beginning */ + char *new_branch , *modename = NULL; + struct nameidata nd; + + /* + * optarg can be of several forms: + * + * /bar:/foo insert /foo before /bar + * /bar:/foo=ro insert /foo in ro mode before /bar + * /foo insert /foo in the beginning (prepend) + * :/foo insert /foo at the end (append) + */ + if (*optarg == ':') { /* append? */ + new_branch = optarg + 1; /* skip ':' */ + idx = cur_branches; + goto found_insertion_point; + } + new_branch = strchr(optarg, ':'); + if (!new_branch) { /* prepend? */ + new_branch = optarg; + goto found_insertion_point; + } + *new_branch++ = '\0'; /* holds path+mode of new branch */ + + /* + * Find matching branch index. For now, this assumes that nothing + * has been mounted on top of this Unionfs stack. Once we have /odf + * and cache-coherency resolved, we'll address the branch-path + * uniqueness. + */ + err = path_lookup(optarg, LOOKUP_FOLLOW, &nd); + if (err) { + printk(KERN_ERR "unionfs: error accessing " + "lower directory \"%s\" (error %d)\n", + optarg, err); + goto out; + } + for (idx = 0; idx < cur_branches; idx++) + if (nd.mnt == new_lower_paths[idx].mnt && + nd.dentry == new_lower_paths[idx].dentry) + break; + path_release(&nd); /* no longer needed */ + if (idx == cur_branches) { + printk(KERN_ERR "unionfs: branch \"%s\" " + "not found\n", optarg); + err = -ENOENT; + goto out; + } + + /* + * At this point idx will hold the index where the new branch should + * be inserted before. + */ +found_insertion_point: + /* find the mode for the new branch */ + if (new_branch) + modename = strchr(new_branch, '='); + if (modename) + *modename++ = '\0'; + if (!new_branch || !*new_branch) { + printk(KERN_ERR "unionfs: null new branch\n"); + err = -EINVAL; + goto out; + } + err = parse_branch_mode(modename, &perms); + if (err) { + printk(KERN_ERR "unionfs: invalid mode \"%s\" for " + "branch \"%s\"\n", modename, new_branch); + goto out; + } + err = path_lookup(new_branch, LOOKUP_FOLLOW, &nd); + if (err) { + printk(KERN_ERR "unionfs: error accessing " + "lower directory \"%s\" (error %d)\n", + new_branch, err); + goto out; + } + /* + * It's probably safe to check_mode the new branch to insert. Note: + * we don't allow inserting branches which are unionfs's by + * themselves (check_branch returns EINVAL in that case). This is + * because this code base doesn't support stacking unionfs: the ODF + * code base supports that correctly. + */ + err = check_branch(&nd); + if (err) { + printk(KERN_ERR "unionfs: lower directory " + "\"%s\" is not a valid branch\n", optarg); + path_release(&nd); + goto out; + } + + /* + * Now we have to insert the new branch. But first, move the bits + * to make space for the new branch, if needed. Finally, adjust + * cur_branches. + * We don't release nd here; it's kept until umount/remount. + */ + if (idx < cur_branches) { + /* if idx==cur_branches, we append: easy */ + memmove(&new_data[idx+1], &new_data[idx], + (cur_branches - idx) * sizeof(struct unionfs_data)); + memmove(&new_lower_paths[idx+1], &new_lower_paths[idx], + (cur_branches - idx) * sizeof(struct path)); + } + new_lower_paths[idx].dentry = nd.dentry; + new_lower_paths[idx].mnt = nd.mnt; + + new_data[idx].sb = nd.dentry->d_sb; + atomic_set(&new_data[idx].open_files, 0); + new_data[idx].branchperms = perms; + new_data[idx].branch_id = ++*high_branch_id; /* assign new branch ID */ + + err = 0; +out: + return err; +} + + +/* + * Support branch management options on remount. + * + * See Documentation/filesystems/unionfs/ for details. + * + * @flags: numeric mount options + * @options: mount options string + * + * This function can rearrange a mounted union dynamically, adding and + * removing branches, including changing branch modes. Clearly this has to + * be done safely and atomically. Luckily, the VFS already calls this + * function with lock_super(sb) and lock_kernel() held, preventing + * concurrent mixing of new mounts, remounts, and unmounts. Moreover, + * do_remount_sb(), our caller function, already called shrink_dcache_sb(sb) + * to purge dentries/inodes from our superblock, and also called + * fsync_super(sb) to purge any dirty pages. So we're good. + * + * XXX: however, our remount code may also need to invalidate mapped pages + * so as to force them to be re-gotten from the (newly reconfigured) lower + * branches. This has to wait for proper mmap and cache coherency support + * in the VFS. + * + */ +static int unionfs_remount_fs(struct super_block *sb, int *flags, + char *options) +{ + int err = 0; + int i; + char *optionstmp, *tmp_to_free; /* kstrdup'ed of "options" */ + char *optname; + int cur_branches = 0; /* no. of current branches */ + int new_branches = 0; /* no. of branches actually left in the end */ + int add_branches; /* est. no. of branches to add */ + int del_branches; /* est. no. of branches to del */ + int max_branches; /* max possible no. of branches */ + struct unionfs_data *new_data = NULL, *tmp_data = NULL; + struct path *new_lower_paths = NULL, *tmp_lower_paths = NULL; + struct inode **new_lower_inodes = NULL; + int new_high_branch_id; /* new high branch ID */ + int size; /* memory allocation size, temp var */ + int old_ibstart, old_ibend; + + unionfs_write_lock(sb); + + /* + * The VFS will take care of "ro" and "rw" flags, and we can safely + * ignore MS_SILENT, but anything else left over is an error. So we + * need to check if any other flags may have been passed (none are + * allowed/supported as of now). + */ + if ((*flags & ~(MS_RDONLY | MS_SILENT)) != 0) { + printk(KERN_ERR + "unionfs: remount flags 0x%x unsupported\n", *flags); + err = -EINVAL; + goto out_error; + } + + /* + * If 'options' is NULL, it's probably because the user just changed + * the union to a "ro" or "rw" and the VFS took care of it. So + * nothing to do and we're done. + */ + if (!options || options[0] == '\0') + goto out_error; + + /* + * Find out how many branches we will have in the end, counting + * "add" and "del" commands. Copy the "options" string because + * strsep modifies the string and we need it later. + */ + tmp_to_free = kstrdup(options, GFP_KERNEL); + optionstmp = tmp_to_free; + if (unlikely(!optionstmp)) { + err = -ENOMEM; + goto out_free; + } + cur_branches = sbmax(sb); /* current no. branches */ + new_branches = sbmax(sb); + del_branches = 0; + add_branches = 0; + new_high_branch_id = sbhbid(sb); /* save current high_branch_id */ + while ((optname = strsep(&optionstmp, ",")) != NULL) { + char *optarg; + + if (!optname || !*optname) + continue; + + optarg = strchr(optname, '='); + if (optarg) + *optarg++ = '\0'; + + if (!strcmp("add", optname)) + add_branches++; + else if (!strcmp("del", optname)) + del_branches++; + } + kfree(tmp_to_free); + /* after all changes, will we have at least one branch left? */ + if ((new_branches + add_branches - del_branches) < 1) { + printk(KERN_ERR + "unionfs: no branches left after remount\n"); + err = -EINVAL; + goto out_free; + } + + /* + * Since we haven't actually parsed all the add/del options, nor + * have we checked them for errors, we don't know for sure how many + * branches we will have after all changes have taken place. In + * fact, the total number of branches left could be less than what + * we have now. So we need to allocate space for a temporary + * placeholder that is at least as large as the maximum number of + * branches we *could* have, which is the current number plus all + * the additions. Once we're done with these temp placeholders, we + * may have to re-allocate the final size, copy over from the temp, + * and then free the temps (done near the end of this function). + */ + max_branches = cur_branches + add_branches; + /* allocate space for new pointers to lower dentry */ + tmp_data = kcalloc(max_branches, + sizeof(struct unionfs_data), GFP_KERNEL); + if (unlikely(!tmp_data)) { + err = -ENOMEM; + goto out_free; + } + /* allocate space for new pointers to lower paths */ + tmp_lower_paths = kcalloc(max_branches, + sizeof(struct path), GFP_KERNEL); + if (unlikely(!tmp_lower_paths)) { + err = -ENOMEM; + goto out_free; + } + /* copy current info into new placeholders, incrementing refcnts */ + memcpy(tmp_data, UNIONFS_SB(sb)->data, + cur_branches * sizeof(struct unionfs_data)); + memcpy(tmp_lower_paths, UNIONFS_D(sb->s_root)->lower_paths, + cur_branches * sizeof(struct path)); + for (i = 0; i < cur_branches; i++) + pathget(&tmp_lower_paths[i]); /* drop refs at end of fxn */ + + /******************************************************************* + * For each branch command, do path_lookup on the requested branch, + * and apply the change to a temp branch list. To handle errors, we + * already dup'ed the old arrays (above), and increased the refcnts + * on various f/s objects. So now we can do all the path_lookups + * and branch-management commands on the new arrays. If it fail mid + * way, we free the tmp arrays and *put all objects. If we succeed, + * then we free old arrays and *put its objects, and then replace + * the arrays with the new tmp list (we may have to re-allocate the + * memory because the temp lists could have been larger than what we + * actually needed). + *******************************************************************/ + + while ((optname = strsep(&options, ",")) != NULL) { + char *optarg; + + if (!optname || !*optname) + continue; + /* + * At this stage optname holds a comma-delimited option, but + * without the commas. Next, we need to break the string on + * the '=' symbol to separate CMD=ARG, where ARG itself can + * be KEY=VAL. For example, in mode=/foo=rw, CMD is "mode", + * KEY is "/foo", and VAL is "rw". + */ + optarg = strchr(optname, '='); + if (optarg) + *optarg++ = '\0'; + /* incgen remount option (instead of old ioctl) */ + if (!strcmp("incgen", optname)) { + err = 0; + goto out_no_change; + } + + /* + * All of our options take an argument now. (Insert ones + * that don't above this check.) So at this stage optname + * contains the CMD part and optarg contains the ARG part. + */ + if (!optarg || !*optarg) { + printk(KERN_ERR "unionfs: all remount options require " + "an argument (%s)\n", optname); + err = -EINVAL; + goto out_release; + } + + if (!strcmp("add", optname)) { + err = do_remount_add_option(optarg, new_branches, + tmp_data, + tmp_lower_paths, + &new_high_branch_id); + if (err) + goto out_release; + new_branches++; + if (new_branches > UNIONFS_MAX_BRANCHES) { + printk(KERN_ERR "unionfs: command exceeds " + "%d branches\n", UNIONFS_MAX_BRANCHES); + err = -E2BIG; + goto out_release; + } + continue; + } + if (!strcmp("del", optname)) { + err = do_remount_del_option(optarg, new_branches, + tmp_data, + tmp_lower_paths); + if (err) + goto out_release; + new_branches--; + continue; + } + if (!strcmp("mode", optname)) { + err = do_remount_mode_option(optarg, new_branches, + tmp_data, + tmp_lower_paths); + if (err) + goto out_release; + continue; + } + + /* + * When you use "mount -o remount,ro", mount(8) will + * reportedly pass the original dirs= string from + * /proc/mounts. So for now, we have to ignore dirs= and + * not consider it an error, unless we want to allow users + * to pass dirs= in remount. Note that to allow the VFS to + * actually process the ro/rw remount options, we have to + * return 0 from this function. + */ + if (!strcmp("dirs", optname)) { + printk(KERN_WARNING + "unionfs: remount ignoring option \"%s\"\n", + optname); + continue; + } + + err = -EINVAL; + printk(KERN_ERR + "unionfs: unrecognized option \"%s\"\n", optname); + goto out_release; + } + +out_no_change: + + /****************************************************************** + * WE'RE ALMOST DONE: check if leftmost branch might be read-only, + * see if we need to allocate a small-sized new vector, copy the + * vectors to their correct place, release the refcnt of the older + * ones, and return. Also handle invalidating any pages that will + * have to be re-read. + *******************************************************************/ + + if (!(tmp_data[0].branchperms & MAY_WRITE)) { + printk(KERN_ERR "unionfs: leftmost branch cannot be read-only " + "(use \"remount,ro\" to create a read-only union)\n"); + err = -EINVAL; + goto out_release; + } + + /* (re)allocate space for new pointers to lower dentry */ + size = new_branches * sizeof(struct unionfs_data); + new_data = krealloc(tmp_data, size, GFP_KERNEL); + if (unlikely(!new_data)) { + err = -ENOMEM; + goto out_release; + } + + /* allocate space for new pointers to lower paths */ + size = new_branches * sizeof(struct path); + new_lower_paths = krealloc(tmp_lower_paths, size, GFP_KERNEL); + if (unlikely(!new_lower_paths)) { + err = -ENOMEM; + goto out_release; + } + + /* allocate space for new pointers to lower inodes */ + new_lower_inodes = kcalloc(new_branches, + sizeof(struct inode *), GFP_KERNEL); + if (unlikely(!new_lower_inodes)) { + err = -ENOMEM; + goto out_release; + } + + /* + * OK, just before we actually put the new set of branches in place, + * we need to ensure that our own f/s has no dirty objects left. + * Luckily, do_remount_sb() already calls shrink_dcache_sb(sb) and + * fsync_super(sb), taking care of dentries, inodes, and dirty + * pages. So all that's left is for us to invalidate any leftover + * (non-dirty) pages to ensure that they will be re-read from the + * new lower branches (and to support mmap). + */ + + /* + * Once we finish the remounting successfully, our superblock + * generation number will have increased. This will be detected by + * our dentry-revalidation code upon subsequent f/s operations + * through unionfs. The revalidation code will rebuild the union of + * lower inodes for a given unionfs inode and invalidate any pages + * of such "stale" inodes (by calling our purge_inode_data + * function). This revalidation will happen lazily and + * incrementally, as users perform operations on cached inodes. We + * would like to encourage this revalidation to happen sooner if + * possible, so we try to invalidate as many other pages in our + * superblock as we can. + */ + purge_sb_data(sb); + + /* copy new vectors into their correct place */ + tmp_data = UNIONFS_SB(sb)->data; + UNIONFS_SB(sb)->data = new_data; + new_data = NULL; /* so don't free good pointers below */ + tmp_lower_paths = UNIONFS_D(sb->s_root)->lower_paths; + UNIONFS_D(sb->s_root)->lower_paths = new_lower_paths; + new_lower_paths = NULL; /* so don't free good pointers below */ + + /* update our unionfs_sb_info and root dentry index of last branch */ + i = sbmax(sb); /* save no. of branches to release at end */ + sbend(sb) = new_branches - 1; + set_dbend(sb->s_root, new_branches - 1); + old_ibstart = ibstart(sb->s_root->d_inode); + old_ibend = ibend(sb->s_root->d_inode); + ibend(sb->s_root->d_inode) = new_branches - 1; + UNIONFS_D(sb->s_root)->bcount = new_branches; + new_branches = i; /* no. of branches to release below */ + + /* + * Update lower inodes: 3 steps + * 1. grab ref on all new lower inodes + */ + for (i = dbstart(sb->s_root); i <= dbend(sb->s_root); i++) { + struct dentry *lower_dentry = + unionfs_lower_dentry_idx(sb->s_root, i); + igrab(lower_dentry->d_inode); + new_lower_inodes[i] = lower_dentry->d_inode; + } + /* 2. release reference on all older lower inodes */ + for (i = old_ibstart; i <= old_ibend; i++) { + iput(unionfs_lower_inode_idx(sb->s_root->d_inode, i)); + unionfs_set_lower_inode_idx(sb->s_root->d_inode, i, NULL); + } + kfree(UNIONFS_I(sb->s_root->d_inode)->lower_inodes); + /* 3. update root dentry's inode to new lower_inodes array */ + UNIONFS_I(sb->s_root->d_inode)->lower_inodes = new_lower_inodes; + new_lower_inodes = NULL; + + /* maxbytes may have changed */ + sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes; + /* update high branch ID */ + sbhbid(sb) = new_high_branch_id; + + /* update our sb->generation for revalidating objects */ + i = atomic_inc_return(&UNIONFS_SB(sb)->generation); + atomic_set(&UNIONFS_D(sb->s_root)->generation, i); + atomic_set(&UNIONFS_I(sb->s_root->d_inode)->generation, i); + if (!(*flags & MS_SILENT)) + pr_info("unionfs: new generation number %d\n", i); + /* finally, update the root dentry's times */ + unionfs_copy_attr_times(sb->s_root->d_inode); + err = 0; /* reset to success */ + + /* + * The code above falls through to the next label, and releases the + * refcnts of the older ones (stored in tmp_*): if we fell through + * here, it means success. However, if we jump directly to this + * label from any error above, then an error occurred after we + * grabbed various refcnts, and so we have to release the + * temporarily constructed structures. + */ +out_release: + /* no need to cleanup/release anything in tmp_data */ + if (tmp_lower_paths) + for (i = 0; i < new_branches; i++) + pathput(&tmp_lower_paths[i]); +out_free: + kfree(tmp_lower_paths); + kfree(tmp_data); + kfree(new_lower_paths); + kfree(new_data); + kfree(new_lower_inodes); +out_error: + unionfs_check_dentry(sb->s_root); + unionfs_write_unlock(sb); + return err; +} + +/* + * Called by iput() when the inode reference count reached zero + * and the inode is not hashed anywhere. Used to clear anything + * that needs to be, before the inode is completely destroyed and put + * on the inode free list. + * + * No need to lock sb info's rwsem. + */ +static void unionfs_clear_inode(struct inode *inode) +{ + int bindex, bstart, bend; + struct inode *lower_inode; + struct list_head *pos, *n; + struct unionfs_dir_state *rdstate; + + list_for_each_safe(pos, n, &UNIONFS_I(inode)->readdircache) { + rdstate = list_entry(pos, struct unionfs_dir_state, cache); + list_del(&rdstate->cache); + free_rdstate(rdstate); + } + + /* + * Decrement a reference to a lower_inode, which was incremented + * by our read_inode when it was created initially. + */ + bstart = ibstart(inode); + bend = ibend(inode); + if (bstart >= 0) { + for (bindex = bstart; bindex <= bend; bindex++) { + lower_inode = unionfs_lower_inode_idx(inode, bindex); + if (!lower_inode) + continue; + iput(lower_inode); + } + } + + kfree(UNIONFS_I(inode)->lower_inodes); + UNIONFS_I(inode)->lower_inodes = NULL; +} + +static struct inode *unionfs_alloc_inode(struct super_block *sb) +{ + struct unionfs_inode_info *i; + + i = kmem_cache_alloc(unionfs_inode_cachep, GFP_KERNEL); + if (unlikely(!i)) + return NULL; + + /* memset everything up to the inode to 0 */ + memset(i, 0, offsetof(struct unionfs_inode_info, vfs_inode)); + + i->vfs_inode.i_version = 1; + return &i->vfs_inode; +} + +static void unionfs_destroy_inode(struct inode *inode) +{ + kmem_cache_free(unionfs_inode_cachep, UNIONFS_I(inode)); +} + +/* unionfs inode cache constructor */ +static void init_once(struct kmem_cache *cachep, void *obj) +{ + struct unionfs_inode_info *i = obj; + + inode_init_once(&i->vfs_inode); +} + +int unionfs_init_inode_cache(void) +{ + int err = 0; + + unionfs_inode_cachep = + kmem_cache_create("unionfs_inode_cache", + sizeof(struct unionfs_inode_info), 0, + SLAB_RECLAIM_ACCOUNT, init_once); + if (unlikely(!unionfs_inode_cachep)) + err = -ENOMEM; + return err; +} + +/* unionfs inode cache destructor */ +void unionfs_destroy_inode_cache(void) +{ + if (unionfs_inode_cachep) + kmem_cache_destroy(unionfs_inode_cachep); +} + +/* + * Called when we have a dirty inode, right here we only throw out + * parts of our readdir list that are too old. + * + * No need to grab sb info's rwsem. + */ +static int unionfs_write_inode(struct inode *inode, int sync) +{ + struct list_head *pos, *n; + struct unionfs_dir_state *rdstate; + + spin_lock(&UNIONFS_I(inode)->rdlock); + list_for_each_safe(pos, n, &UNIONFS_I(inode)->readdircache) { + rdstate = list_entry(pos, struct unionfs_dir_state, cache); + /* We keep this list in LRU order. */ + if ((rdstate->access + RDCACHE_JIFFIES) > jiffies) + break; + UNIONFS_I(inode)->rdcount--; + list_del(&rdstate->cache); + free_rdstate(rdstate); + } + spin_unlock(&UNIONFS_I(inode)->rdlock); + + return 0; +} + +/* + * Used only in nfs, to kill any pending RPC tasks, so that subsequent + * code can actually succeed and won't leave tasks that need handling. + */ +static void unionfs_umount_begin(struct vfsmount *mnt, int flags) +{ + struct super_block *sb, *lower_sb; + struct vfsmount *lower_mnt; + int bindex, bstart, bend; + + if (!(flags & MNT_FORCE)) + /* + * we are not being MNT_FORCE'd, therefore we should emulate + * old behavior + */ + return; + + sb = mnt->mnt_sb; + + unionfs_read_lock(sb); + + bstart = sbstart(sb); + bend = sbend(sb); + for (bindex = bstart; bindex <= bend; bindex++) { + lower_mnt = unionfs_lower_mnt_idx(sb->s_root, bindex); + lower_sb = unionfs_lower_super_idx(sb, bindex); + + if (lower_mnt && lower_sb && lower_sb->s_op && + lower_sb->s_op->umount_begin) + lower_sb->s_op->umount_begin(lower_mnt, flags); + } + + unionfs_read_unlock(sb); +} + +static int unionfs_show_options(struct seq_file *m, struct vfsmount *mnt) +{ + struct super_block *sb = mnt->mnt_sb; + int ret = 0; + char *tmp_page; + char *path; + int bindex, bstart, bend; + int perms; + + unionfs_read_lock(sb); + + unionfs_lock_dentry(sb->s_root); + + tmp_page = (char *) __get_free_page(GFP_KERNEL); + if (unlikely(!tmp_page)) { + ret = -ENOMEM; + goto out; + } + + bstart = sbstart(sb); + bend = sbend(sb); + + seq_printf(m, ",dirs="); + for (bindex = bstart; bindex <= bend; bindex++) { + path = d_path(unionfs_lower_dentry_idx(sb->s_root, bindex), + unionfs_lower_mnt_idx(sb->s_root, bindex), + tmp_page, PAGE_SIZE); + if (IS_ERR(path)) { + ret = PTR_ERR(path); + goto out; + } + + perms = branchperms(sb, bindex); + + seq_printf(m, "%s=%s", path, + perms & MAY_WRITE ? "rw" : "ro"); + if (bindex != bend) + seq_printf(m, ":"); + } + +out: + free_page((unsigned long) tmp_page); + + unionfs_unlock_dentry(sb->s_root); + + unionfs_read_unlock(sb); + + return ret; +} + +struct super_operations unionfs_sops = { + .read_inode = unionfs_read_inode, + .delete_inode = unionfs_delete_inode, + .put_super = unionfs_put_super, + .statfs = unionfs_statfs, + .remount_fs = unionfs_remount_fs, + .clear_inode = unionfs_clear_inode, + .umount_begin = unionfs_umount_begin, + .show_options = unionfs_show_options, + .write_inode = unionfs_write_inode, + .alloc_inode = unionfs_alloc_inode, + .destroy_inode = unionfs_destroy_inode, +}; diff -puN /dev/null fs/unionfs/union.h --- /dev/null +++ a/fs/unionfs/union.h @@ -0,0 +1,592 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _UNION_H_ +#define _UNION_H_ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +/* the file system name */ +#define UNIONFS_NAME "unionfs" + +/* unionfs root inode number */ +#define UNIONFS_ROOT_INO 1 + +/* number of times we try to get a unique temporary file name */ +#define GET_TMPNAM_MAX_RETRY 5 + +/* maximum number of branches we support, to avoid memory blowup */ +#define UNIONFS_MAX_BRANCHES 128 + +/* minimum time (seconds) required for time-based cache-coherency */ +#define UNIONFS_MIN_CC_TIME 3 + +/* Operations vectors defined in specific files. */ +extern struct file_operations unionfs_main_fops; +extern struct file_operations unionfs_dir_fops; +extern struct inode_operations unionfs_main_iops; +extern struct inode_operations unionfs_dir_iops; +extern struct inode_operations unionfs_symlink_iops; +extern struct super_operations unionfs_sops; +extern struct dentry_operations unionfs_dops; +extern struct address_space_operations unionfs_aops; + +/* How long should an entry be allowed to persist */ +#define RDCACHE_JIFFIES (5*HZ) + +/* file private data. */ +struct unionfs_file_info { + int bstart; + int bend; + atomic_t generation; + + struct unionfs_dir_state *rdstate; + struct file **lower_files; + int *saved_branch_ids; /* IDs of branches when file was opened */ +}; + +/* unionfs inode data in memory */ +struct unionfs_inode_info { + int bstart; + int bend; + atomic_t generation; + int stale; + /* Stuff for readdir over NFS. */ + spinlock_t rdlock; + struct list_head readdircache; + int rdcount; + int hashsize; + int cookie; + + /* The lower inodes */ + struct inode **lower_inodes; + + struct inode vfs_inode; +}; + +/* unionfs dentry data in memory */ +struct unionfs_dentry_info { + /* + * The semaphore is used to lock the dentry as soon as we get into a + * unionfs function from the VFS. Our lock ordering is that children + * go before their parents. + */ + struct mutex lock; + int bstart; + int bend; + int bopaque; + int bcount; + atomic_t generation; + struct path *lower_paths; +}; + +/* These are the pointers to our various objects. */ +struct unionfs_data { + struct super_block *sb; + atomic_t open_files; /* number of open files on branch */ + int branchperms; + int branch_id; /* unique branch ID at re/mount time */ +}; + +/* unionfs super-block data in memory */ +struct unionfs_sb_info { + int bend; + + atomic_t generation; + + /* + * This rwsem is used to make sure that a branch management + * operation... + * 1) will not begin before all currently in-flight operations + * complete. + * 2) any new operations do not execute until the currently + * running branch management operation completes. + * + * The write_lock_owner records the PID of the task which grabbed + * the rw_sem for writing. If the same task also tries to grab the + * read lock, we allow it. This prevents a self-deadlock when + * branch-management is used on a pivot_root'ed union, because we + * have to ->lookup paths which belong to the same union. + */ + struct rw_semaphore rwsem; + pid_t write_lock_owner; /* PID of rw_sem owner (write lock) */ + int high_branch_id; /* last unique branch ID given */ + struct unionfs_data *data; +}; + +/* + * structure for making the linked list of entries by readdir on left branch + * to compare with entries on right branch + */ +struct filldir_node { + struct list_head file_list; /* list for directory entries */ + char *name; /* name entry */ + int hash; /* name hash */ + int namelen; /* name len since name is not 0 terminated */ + + /* + * we can check for duplicate whiteouts and files in the same branch + * in order to return -EIO. + */ + int bindex; + + /* is this a whiteout entry? */ + int whiteout; + + /* Inline name, so we don't need to separately kmalloc small ones */ + char iname[DNAME_INLINE_LEN_MIN]; +}; + +/* Directory hash table. */ +struct unionfs_dir_state { + unsigned int cookie; /* the cookie, based off of rdversion */ + unsigned int offset; /* The entry we have returned. */ + int bindex; + loff_t dirpos; /* offset within the lower level directory */ + int size; /* How big is the hash table? */ + int hashentries; /* How many entries have been inserted? */ + unsigned long access; + + /* This cache list is used when the inode keeps us around. */ + struct list_head cache; + struct list_head list[0]; +}; + +/* externs needed for fanout.h or sioq.h */ +extern int unionfs_get_nlinks(const struct inode *inode); + +/* include miscellaneous macros */ +#include "fanout.h" +#include "sioq.h" + +/* externs for cache creation/deletion routines */ +extern void unionfs_destroy_filldir_cache(void); +extern int unionfs_init_filldir_cache(void); +extern int unionfs_init_inode_cache(void); +extern void unionfs_destroy_inode_cache(void); +extern int unionfs_init_dentry_cache(void); +extern void unionfs_destroy_dentry_cache(void); + +/* Initialize and free readdir-specific state. */ +extern int init_rdstate(struct file *file); +extern struct unionfs_dir_state *alloc_rdstate(struct inode *inode, + int bindex); +extern struct unionfs_dir_state *find_rdstate(struct inode *inode, + loff_t fpos); +extern void free_rdstate(struct unionfs_dir_state *state); +extern int add_filldir_node(struct unionfs_dir_state *rdstate, + const char *name, int namelen, int bindex, + int whiteout); +extern struct filldir_node *find_filldir_node(struct unionfs_dir_state *rdstate, + const char *name, int namelen, + int is_whiteout); + +extern struct dentry **alloc_new_dentries(int objs); +extern struct unionfs_data *alloc_new_data(int objs); + +/* We can only use 32-bits of offset for rdstate --- blech! */ +#define DIREOF (0xfffff) +#define RDOFFBITS 20 /* This is the number of bits in DIREOF. */ +#define MAXRDCOOKIE (0xfff) +/* Turn an rdstate into an offset. */ +static inline off_t rdstate2offset(struct unionfs_dir_state *buf) +{ + off_t tmp; + + tmp = ((buf->cookie & MAXRDCOOKIE) << RDOFFBITS) + | (buf->offset & DIREOF); + return tmp; +} + +static inline void unionfs_read_lock(struct super_block *sb) +{ + if (UNIONFS_SB(sb)->write_lock_owner && + UNIONFS_SB(sb)->write_lock_owner == current->pid) + return; + down_read(&UNIONFS_SB(sb)->rwsem); +} +static inline void unionfs_read_unlock(struct super_block *sb) +{ + if (UNIONFS_SB(sb)->write_lock_owner && + UNIONFS_SB(sb)->write_lock_owner == current->pid) + return; + up_read(&UNIONFS_SB(sb)->rwsem); +} +static inline void unionfs_write_lock(struct super_block *sb) +{ + down_write(&UNIONFS_SB(sb)->rwsem); + UNIONFS_SB(sb)->write_lock_owner = current->pid; +} +static inline void unionfs_write_unlock(struct super_block *sb) +{ + up_write(&UNIONFS_SB(sb)->rwsem); + UNIONFS_SB(sb)->write_lock_owner = 0; +} + +static inline void unionfs_double_lock_dentry(struct dentry *d1, + struct dentry *d2) +{ + if (d2 < d1) { + struct dentry *tmp = d1; + d1 = d2; + d2 = tmp; + } + unionfs_lock_dentry(d1); + unionfs_lock_dentry(d2); +} + +extern int new_dentry_private_data(struct dentry *dentry); +extern void free_dentry_private_data(struct dentry *dentry); +extern void update_bstart(struct dentry *dentry); +extern int init_lower_nd(struct nameidata *nd, unsigned int flags); +extern void release_lower_nd(struct nameidata *nd, int err); + +/* + * EXTERNALS: + */ + +/* replicates the directory structure up to given dentry in given branch */ +extern struct dentry *create_parents(struct inode *dir, struct dentry *dentry, + const char *name, int bindex); +extern int make_dir_opaque(struct dentry *dir, int bindex); + +/* partial lookup */ +extern int unionfs_partial_lookup(struct dentry *dentry); + +/* + * Pass an unionfs dentry and an index and it will try to create a whiteout + * in branch 'index'. + * + * On error, it will proceed to a branch to the left + */ +extern int create_whiteout(struct dentry *dentry, int start); +/* copies a file from dbstart to newbindex branch */ +extern int copyup_file(struct inode *dir, struct file *file, int bstart, + int newbindex, loff_t size); +extern int copyup_named_file(struct inode *dir, struct file *file, + char *name, int bstart, int new_bindex, + loff_t len); +/* copies a dentry from dbstart to newbindex branch */ +extern int copyup_dentry(struct inode *dir, struct dentry *dentry, + int bstart, int new_bindex, const char *name, + int namelen, struct file **copyup_file, loff_t len); +/* helper functions for post-copyup actions */ +extern void unionfs_postcopyup_setmnt(struct dentry *dentry); +extern void unionfs_postcopyup_release(struct dentry *dentry); + +extern int remove_whiteouts(struct dentry *dentry, + struct dentry *lower_dentry, int bindex); + +extern int do_delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist); + +/* Is this directory empty: 0 if it is empty, -ENOTEMPTY if not. */ +extern int check_empty(struct dentry *dentry, + struct unionfs_dir_state **namelist); +/* Delete whiteouts from this directory in branch bindex. */ +extern int delete_whiteouts(struct dentry *dentry, int bindex, + struct unionfs_dir_state *namelist); + +/* Re-lookup a lower dentry. */ +extern int unionfs_refresh_lower_dentry(struct dentry *dentry, int bindex); + +extern void unionfs_reinterpose(struct dentry *this_dentry); +extern struct super_block *unionfs_duplicate_super(struct super_block *sb); + +/* Locking functions. */ +extern int unionfs_setlk(struct file *file, int cmd, struct file_lock *fl); +extern int unionfs_getlk(struct file *file, struct file_lock *fl); + +/* Common file operations. */ +extern int unionfs_file_revalidate(struct file *file, bool willwrite); +extern int unionfs_open(struct inode *inode, struct file *file); +extern int unionfs_file_release(struct inode *inode, struct file *file); +extern int unionfs_flush(struct file *file, fl_owner_t id); +extern long unionfs_ioctl(struct file *file, unsigned int cmd, + unsigned long arg); +extern int unionfs_fsync(struct file *file, struct dentry *dentry, + int datasync); +extern int unionfs_fasync(int fd, struct file *file, int flag); + +/* Inode operations */ +extern int unionfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry); +extern int unionfs_unlink(struct inode *dir, struct dentry *dentry); +extern int unionfs_rmdir(struct inode *dir, struct dentry *dentry); + +extern bool __unionfs_d_revalidate_chain(struct dentry *dentry, + struct nameidata *nd, bool willwrite); +extern bool is_newer_lower(const struct dentry *dentry); +extern void purge_sb_data(struct super_block *sb); + +/* The values for unionfs_interpose's flag. */ +#define INTERPOSE_DEFAULT 0 +#define INTERPOSE_LOOKUP 1 +#define INTERPOSE_REVAL 2 +#define INTERPOSE_REVAL_NEG 3 +#define INTERPOSE_PARTIAL 4 + +extern struct dentry *unionfs_interpose(struct dentry *this_dentry, + struct super_block *sb, int flag); + +#ifdef CONFIG_UNION_FS_XATTR +/* Extended attribute functions. */ +extern void *unionfs_xattr_alloc(size_t size, size_t limit); +static inline void unionfs_xattr_kfree(const void *p) +{ + kfree(p); +} +extern ssize_t unionfs_getxattr(struct dentry *dentry, const char *name, + void *value, size_t size); +extern int unionfs_removexattr(struct dentry *dentry, const char *name); +extern ssize_t unionfs_listxattr(struct dentry *dentry, char *list, + size_t size); +extern int unionfs_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags); +#endif /* CONFIG_UNION_FS_XATTR */ + +/* The root directory is unhashed, but isn't deleted. */ +static inline int d_deleted(struct dentry *d) +{ + return d_unhashed(d) && (d != d->d_sb->s_root); +} + +struct dentry *unionfs_lookup_backend(struct dentry *dentry, + struct nameidata *nd, int lookupmode); + +/* unionfs_permission, check if we should bypass error to facilitate copyup */ +#define IS_COPYUP_ERR(err) ((err) == -EROFS) + +/* unionfs_open, check if we need to copyup the file */ +#define OPEN_WRITE_FLAGS (O_WRONLY | O_RDWR | O_APPEND) +#define IS_WRITE_FLAG(flag) ((flag) & OPEN_WRITE_FLAGS) + +static inline int branchperms(const struct super_block *sb, int index) +{ + BUG_ON(index < 0); + return UNIONFS_SB(sb)->data[index].branchperms; +} + +static inline int set_branchperms(struct super_block *sb, int index, int perms) +{ + BUG_ON(index < 0); + UNIONFS_SB(sb)->data[index].branchperms = perms; + return perms; +} + +/* Is this file on a read-only branch? */ +static inline int is_robranch_super(const struct super_block *sb, int index) +{ + int ret; + + ret = (!(branchperms(sb, index) & MAY_WRITE)) ? -EROFS : 0; + return ret; +} + +/* Is this file on a read-only branch? */ +static inline int is_robranch_idx(const struct dentry *dentry, int index) +{ + struct super_block *lower_sb; + + BUG_ON(index < 0); + + if (!(branchperms(dentry->d_sb, index) & MAY_WRITE)) + return -EROFS; + + lower_sb = unionfs_lower_super_idx(dentry->d_sb, index); + BUG_ON(lower_sb == NULL); + /* + * test sb flags directly, not IS_RDONLY(lower_inode) because the + * lower_dentry could be a negative. + */ + if (lower_sb->s_flags & MS_RDONLY) + return -EROFS; + + return 0; +} + +static inline int is_robranch(const struct dentry *dentry) +{ + int index; + + index = UNIONFS_D(dentry)->bstart; + BUG_ON(index < 0); + + return is_robranch_idx(dentry, index); +} + +/* What do we use for whiteouts. */ +#define UNIONFS_WHPFX ".wh." +#define UNIONFS_WHLEN 4 +/* + * If a directory contains this file, then it is opaque. We start with the + * .wh. flag so that it is blocked by lookup. + */ +#define UNIONFS_DIR_OPAQUE_NAME "__dir_opaque" +#define UNIONFS_DIR_OPAQUE UNIONFS_WHPFX UNIONFS_DIR_OPAQUE_NAME + +/* + * EXTERNALS: + */ +extern char *alloc_whname(const char *name, int len); +extern int check_branch(struct nameidata *nd); +extern int parse_branch_mode(const char *name, int *perms); + +/* + * These two functions are here because it is kind of daft to copy and paste + * the contents of the two functions to 32+ places in unionfs + */ +static inline struct dentry *lock_parent(struct dentry *dentry) +{ + struct dentry *dir = dget(dentry->d_parent); + + mutex_lock(&dir->d_inode->i_mutex); + return dir; +} + +static inline void unlock_dir(struct dentry *dir) +{ + mutex_unlock(&dir->d_inode->i_mutex); + dput(dir); +} + +static inline struct vfsmount *unionfs_mntget(struct dentry *dentry, + int bindex) +{ + struct vfsmount *mnt; + + BUG_ON(!dentry || bindex < 0); + + mnt = mntget(unionfs_lower_mnt_idx(dentry, bindex)); +#ifdef CONFIG_UNION_FS_DEBUG + if (!mnt) + pr_debug("unionfs: mntget: mnt=%p bindex=%d\n", + mnt, bindex); +#endif /* CONFIG_UNION_FS_DEBUG */ + + return mnt; +} + +static inline void unionfs_mntput(struct dentry *dentry, int bindex) +{ + struct vfsmount *mnt; + + if (!dentry && bindex < 0) + return; + BUG_ON(!dentry || bindex < 0); + + mnt = unionfs_lower_mnt_idx(dentry, bindex); +#ifdef CONFIG_UNION_FS_DEBUG + /* + * Directories can have NULL lower objects in between start/end, but + * NOT if at the start/end range. We cannot verify that this dentry + * is a type=DIR, because it may already be a negative dentry. But + * if dbstart is greater than dbend, we know that this couldn't have + * been a regular file: it had to have been a directory. + */ + if (!mnt && !(bindex > dbstart(dentry) && bindex < dbend(dentry))) + pr_debug("unionfs: mntput: mnt=%p bindex=%d\n", mnt, bindex); +#endif /* CONFIG_UNION_FS_DEBUG */ + mntput(mnt); +} + +#ifdef CONFIG_UNION_FS_DEBUG + +/* useful for tracking code reachability */ +#define UDBG pr_debug("DBG:%s:%s:%d\n", __FILE__, __FUNCTION__, __LINE__) + +#define unionfs_check_inode(i) __unionfs_check_inode((i), \ + __FILE__, __FUNCTION__, __LINE__) +#define unionfs_check_dentry(d) __unionfs_check_dentry((d), \ + __FILE__, __FUNCTION__, __LINE__) +#define unionfs_check_file(f) __unionfs_check_file((f), \ + __FILE__, __FUNCTION__, __LINE__) +#define unionfs_check_nd(n) __unionfs_check_nd((n), \ + __FILE__, __FUNCTION__, __LINE__) +#define show_branch_counts(sb) __show_branch_counts((sb), \ + __FILE__, __FUNCTION__, __LINE__) +#define show_inode_times(i) __show_inode_times((i), \ + __FILE__, __FUNCTION__, __LINE__) +#define show_dinode_times(d) __show_dinode_times((d), \ + __FILE__, __FUNCTION__, __LINE__) +#define show_inode_counts(i) __show_inode_counts((i), \ + __FILE__, __FUNCTION__, __LINE__) + +extern void __unionfs_check_inode(const struct inode *inode, const char *fname, + const char *fxn, int line); +extern void __unionfs_check_dentry(const struct dentry *dentry, + const char *fname, const char *fxn, + int line); +extern void __unionfs_check_file(const struct file *file, + const char *fname, const char *fxn, int line); +extern void __unionfs_check_nd(const struct nameidata *nd, + const char *fname, const char *fxn, int line); +extern void __show_branch_counts(const struct super_block *sb, + const char *file, const char *fxn, int line); +extern void __show_inode_times(const struct inode *inode, + const char *file, const char *fxn, int line); +extern void __show_dinode_times(const struct dentry *dentry, + const char *file, const char *fxn, int line); +extern void __show_inode_counts(const struct inode *inode, + const char *file, const char *fxn, int line); + +#else /* not CONFIG_UNION_FS_DEBUG */ + +/* we leave useful hooks for these check functions throughout the code */ +#define unionfs_check_inode(i) do { } while (0) +#define unionfs_check_dentry(d) do { } while (0) +#define unionfs_check_file(f) do { } while (0) +#define unionfs_check_nd(n) do { } while (0) +#define show_branch_counts(sb) do { } while (0) +#define show_inode_times(i) do { } while (0) +#define show_dinode_times(d) do { } while (0) +#define show_inode_counts(i) do { } while (0) + +#endif /* not CONFIG_UNION_FS_DEBUG */ + +#endif /* not _UNION_H_ */ diff -puN /dev/null fs/unionfs/unlink.c --- /dev/null +++ a/fs/unionfs/unlink.c @@ -0,0 +1,236 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* unlink a file by creating a whiteout */ +static int unionfs_unlink_whiteout(struct inode *dir, struct dentry *dentry) +{ + struct dentry *lower_dentry; + struct dentry *lower_dir_dentry; + int bindex; + int err = 0; + + err = unionfs_partial_lookup(dentry); + if (err) + goto out; + + bindex = dbstart(dentry); + + lower_dentry = unionfs_lower_dentry_idx(dentry, bindex); + if (!lower_dentry) + goto out; + + lower_dir_dentry = lock_parent(lower_dentry); + + /* avoid destroying the lower inode if the file is in use */ + dget(lower_dentry); + err = is_robranch_super(dentry->d_sb, bindex); + if (!err) + err = vfs_unlink(lower_dir_dentry->d_inode, lower_dentry); + /* if vfs_unlink succeeded, update our inode's times */ + if (!err) + unionfs_copy_attr_times(dentry->d_inode); + dput(lower_dentry); + fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); + unlock_dir(lower_dir_dentry); + + if (err && !IS_COPYUP_ERR(err)) + goto out; + + /* + * We create whiteouts if (1) there was an error unlinking the main + * file; (2) there is a lower priority file with the same name + * (dbopaque); (3) the branch in which the file is not the last + * (rightmost0 branch. The last rule is an optimization to avoid + * creating all those whiteouts if there's no chance they'd be + * masking any lower-priority branch, as well as unionfs is used + * with only one branch (using only one branch, while odd, is still + * possible). + */ + if (err) { + if (dbstart(dentry) == 0) + goto out; + err = create_whiteout(dentry, dbstart(dentry) - 1); + } else if (dbopaque(dentry) != -1) { + err = create_whiteout(dentry, dbopaque(dentry)); + } else if (dbstart(dentry) < sbend(dentry->d_sb)) { + err = create_whiteout(dentry, dbstart(dentry)); + } + +out: + if (!err) + dentry->d_inode->i_nlink--; + + /* We don't want to leave negative leftover dentries for revalidate. */ + if (!err && (dbopaque(dentry) != -1)) + update_bstart(dentry); + + return err; +} + +int unionfs_unlink(struct inode *dir, struct dentry *dentry) +{ + int err = 0; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + unionfs_check_dentry(dentry); + + err = unionfs_unlink_whiteout(dir, dentry); + /* call d_drop so the system "forgets" about us */ + if (!err) { + if (!S_ISDIR(dentry->d_inode->i_mode)) + unionfs_postcopyup_release(dentry); + d_drop(dentry); + /* + * if unlink/whiteout succeeded, parent dir mtime has + * changed + */ + unionfs_copy_attr_times(dir); + } + +out: + if (!err) { + unionfs_check_dentry(dentry); + unionfs_check_inode(dir); + } + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + return err; +} + +static int unionfs_rmdir_first(struct inode *dir, struct dentry *dentry, + struct unionfs_dir_state *namelist) +{ + int err; + struct dentry *lower_dentry; + struct dentry *lower_dir_dentry = NULL; + + /* Here we need to remove whiteout entries. */ + err = delete_whiteouts(dentry, dbstart(dentry), namelist); + if (err) + goto out; + + lower_dentry = unionfs_lower_dentry(dentry); + + lower_dir_dentry = lock_parent(lower_dentry); + + /* avoid destroying the lower inode if the file is in use */ + dget(lower_dentry); + err = is_robranch(dentry); + if (!err) + err = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry); + dput(lower_dentry); + + fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode); + /* propagate number of hard-links */ + dentry->d_inode->i_nlink = unionfs_get_nlinks(dentry->d_inode); + +out: + if (lower_dir_dentry) + unlock_dir(lower_dir_dentry); + return err; +} + +int unionfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + int err = 0; + struct unionfs_dir_state *namelist = NULL; + int dstart, dend; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + unionfs_check_dentry(dentry); + + /* check if this unionfs directory is empty or not */ + err = check_empty(dentry, &namelist); + if (err) + goto out; + + err = unionfs_rmdir_first(dir, dentry, namelist); + dstart = dbstart(dentry); + dend = dbend(dentry); + /* + * We create a whiteout for the directory if there was an error to + * rmdir the first directory entry in the union. Otherwise, we + * create a whiteout only if there is no chance that a lower + * priority branch might also have the same named directory. IOW, + * if there is not another same-named directory at a lower priority + * branch, then we don't need to create a whiteout for it. + */ + if (!err) { + if (dstart < dend) + err = create_whiteout(dentry, dstart); + } else { + int new_err; + + if (dstart == 0) + goto out; + + /* exit if the error returned was NOT -EROFS */ + if (!IS_COPYUP_ERR(err)) + goto out; + + new_err = create_whiteout(dentry, dstart - 1); + if (new_err != -EEXIST) + err = new_err; + } + +out: + /* + * Drop references to lower dentry/inode so storage space for them + * can be reclaimed. Then, call d_drop so the system "forgets" + * about us. + */ + if (!err) { + struct inode *inode = dentry->d_inode; + BUG_ON(!inode); + iput(unionfs_lower_inode_idx(inode, dstart)); + unionfs_set_lower_inode_idx(inode, dstart, NULL); + dput(unionfs_lower_dentry_idx(dentry, dstart)); + unionfs_set_lower_dentry_idx(dentry, dstart, NULL); + /* + * If the last directory is unlinked, then mark istart/end + * as -1, (to maintain the invariant that if there are no + * lower objects, then branch index start and end are set to + * -1). + */ + if (!unionfs_lower_inode_idx(inode, dstart) && + !unionfs_lower_inode_idx(inode, dend)) + ibstart(inode) = ibend(inode) = -1; + d_drop(dentry); + } + + if (namelist) + free_rdstate(namelist); + + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + return err; +} diff -puN /dev/null fs/unionfs/xattr.c --- /dev/null +++ a/fs/unionfs/xattr.c @@ -0,0 +1,153 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2003-2006 Charles P. Wright + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2005-2006 Junjiro Okajima + * Copyright (c) 2005 Arun M. Krishnakumar + * Copyright (c) 2004-2006 David P. Quigley + * Copyright (c) 2003-2004 Mohammad Nayyer Zubair + * Copyright (c) 2003 Puja Gupta + * Copyright (c) 2003 Harikesavan Krishnan + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "union.h" + +/* This is lifted from fs/xattr.c */ +void *unionfs_xattr_alloc(size_t size, size_t limit) +{ + void *ptr; + + if (size > limit) + return ERR_PTR(-E2BIG); + + if (!size) /* size request, no buffer is needed */ + return NULL; + + ptr = kmalloc(size, GFP_KERNEL); + if (unlikely(!ptr)) + return ERR_PTR(-ENOMEM); + return ptr; +} + +/* + * BKL held by caller. + * dentry->d_inode->i_mutex locked + */ +ssize_t unionfs_getxattr(struct dentry *dentry, const char *name, void *value, + size_t size) +{ + struct dentry *lower_dentry = NULL; + int err = -EOPNOTSUPP; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + lower_dentry = unionfs_lower_dentry(dentry); + + err = vfs_getxattr(lower_dentry, (char *) name, value, size); + +out: + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + return err; +} + +/* + * BKL held by caller. + * dentry->d_inode->i_mutex locked + */ +int unionfs_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) +{ + struct dentry *lower_dentry = NULL; + int err = -EOPNOTSUPP; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + lower_dentry = unionfs_lower_dentry(dentry); + + err = vfs_setxattr(lower_dentry, (char *) name, (void *) value, + size, flags); + +out: + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + return err; +} + +/* + * BKL held by caller. + * dentry->d_inode->i_mutex locked + */ +int unionfs_removexattr(struct dentry *dentry, const char *name) +{ + struct dentry *lower_dentry = NULL; + int err = -EOPNOTSUPP; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + lower_dentry = unionfs_lower_dentry(dentry); + + err = vfs_removexattr(lower_dentry, (char *) name); + +out: + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + return err; +} + +/* + * BKL held by caller. + * dentry->d_inode->i_mutex locked + */ +ssize_t unionfs_listxattr(struct dentry *dentry, char *list, size_t size) +{ + struct dentry *lower_dentry = NULL; + int err = -EOPNOTSUPP; + char *encoded_list = NULL; + + unionfs_read_lock(dentry->d_sb); + unionfs_lock_dentry(dentry); + + if (unlikely(!__unionfs_d_revalidate_chain(dentry, NULL, false))) { + err = -ESTALE; + goto out; + } + + lower_dentry = unionfs_lower_dentry(dentry); + + encoded_list = list; + err = vfs_listxattr(lower_dentry, encoded_list, size); + +out: + unionfs_check_dentry(dentry); + unionfs_unlock_dentry(dentry); + unionfs_read_unlock(dentry->d_sb); + return err; +} diff -puN include/linux/fs_stack.h~git-unionfs include/linux/fs_stack.h --- a/include/linux/fs_stack.h~git-unionfs +++ a/include/linux/fs_stack.h @@ -1,17 +1,28 @@ +/* + * Copyright (c) 2006-2007 Erez Zadok + * Copyright (c) 2006-2007 Josef 'Jeff' Sipek + * Copyright (c) 2006-2007 Stony Brook University + * Copyright (c) 2006-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + #ifndef _LINUX_FS_STACK_H #define _LINUX_FS_STACK_H -/* This file defines generic functions used primarily by stackable +/* + * This file defines generic functions used primarily by stackable * filesystems; none of these functions require i_mutex to be held. */ #include /* externs for fs/stack.c */ -extern void fsstack_copy_attr_all(struct inode *dest, const struct inode *src, - int (*get_nlinks)(struct inode *)); - -extern void fsstack_copy_inode_size(struct inode *dst, const struct inode *src); +extern void fsstack_copy_attr_all(struct inode *dest, const struct inode *src); +extern void fsstack_copy_inode_size(struct inode *dst, + const struct inode *src); /* inlines */ static inline void fsstack_copy_attr_atime(struct inode *dest, diff -puN include/linux/magic.h~git-unionfs include/linux/magic.h --- a/include/linux/magic.h~git-unionfs +++ a/include/linux/magic.h @@ -35,6 +35,8 @@ #define REISER2FS_SUPER_MAGIC_STRING "ReIsEr2Fs" #define REISER2FS_JR_SUPER_MAGIC_STRING "ReIsEr3Fs" +#define UNIONFS_SUPER_MAGIC 0xf15f083d + #define SMB_SUPER_MAGIC 0x517B #define USBDEVICE_SUPER_MAGIC 0x9fa2 #define CGROUP_SUPER_MAGIC 0x27e0eb diff -puN include/linux/namei.h~git-unionfs include/linux/namei.h --- a/include/linux/namei.h~git-unionfs +++ a/include/linux/namei.h @@ -3,6 +3,7 @@ #include #include +#include struct vfsmount; @@ -100,4 +101,16 @@ static inline char *nd_get_link(struct n return nd->saved_names[nd->depth]; } +static inline void pathget(struct path *path) +{ + mntget(path->mnt); + dget(path->dentry); +} + +static inline void pathput(struct path *path) +{ + dput(path->dentry); + mntput(path->mnt); +} + #endif /* _LINUX_NAMEI_H */ diff -puN /dev/null include/linux/union_fs.h --- /dev/null +++ a/include/linux/union_fs.h @@ -0,0 +1,24 @@ +/* + * Copyright (c) 2003-2007 Erez Zadok + * Copyright (c) 2005-2007 Josef 'Jeff' Sipek + * Copyright (c) 2003-2007 Stony Brook University + * Copyright (c) 2003-2007 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _LINUX_UNION_FS_H +#define _LINUX_UNION_FS_H + +#define UNIONFS_VERSION "2.1-mm" + +/* + * DEFINITIONS FOR USER AND KERNEL CODE: + */ +# define UNIONFS_IOCTL_INCGEN _IOR(0x15, 11, int) +# define UNIONFS_IOCTL_QUERYFILE _IOR(0x15, 15, int) + +#endif /* _LINUX_UNIONFS_H */ + _