From: Suresh Jayaraman Subject: [PATCH 08/09] cifs: read pages from FS-Cache Read pages from a FS-Cache data storage object into a CIFS inode. Signed-off-by: Suresh Jayaraman Acked-by: David Howells --- fs/cifs/file.c | 17 ++++++++++++ fs/cifs/fscache.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/cifs/fscache.h | 40 ++++++++++++++++++++++++++++- 3 files changed, 129 insertions(+), 1 deletion(-) Index: cifs-2.6/fs/cifs/file.c =================================================================== --- cifs-2.6.orig/fs/cifs/file.c +++ cifs-2.6/fs/cifs/file.c @@ -1981,6 +1981,15 @@ static int cifs_readpages(struct file *f cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); pTcon = cifs_sb->tcon; + /* + * Reads as many pages as possible from fscache. Returns -ENOBUFS + * immediately if the cookie is negative + */ + rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list, + &num_pages); + if (rc == 0) + goto read_complete; + cFYI(DBG2, "rpages: num pages %d", num_pages); for (i = 0; i < num_pages; ) { unsigned contig_pages; @@ -2091,6 +2100,7 @@ static int cifs_readpages(struct file *f smb_read_data = NULL; } +read_complete: FreeXid(xid); return rc; } @@ -2101,6 +2111,11 @@ static int cifs_readpage_worker(struct f char *read_data; int rc; + /* Is the page cached? */ + rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page); + if (rc == 0) + goto read_complete; + page_cache_get(page); read_data = kmap(page); /* for reads over a certain size could initiate async read ahead */ @@ -2129,6 +2144,8 @@ static int cifs_readpage_worker(struct f io_error: kunmap(page); page_cache_release(page); + +read_complete: return rc; } Index: cifs-2.6/fs/cifs/fscache.c =================================================================== --- cifs-2.6.orig/fs/cifs/fscache.c +++ cifs-2.6/fs/cifs/fscache.c @@ -140,6 +140,79 @@ int cifs_fscache_release_page(struct pag return 1; } +static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx, + int error) +{ + cFYI(1, "CFS: readpage_from_fscache_complete (0x%p/%d)", + page, error); + if (!error) + SetPageUptodate(page); + unlock_page(page); +} + +/* + * Retrieve a page from FS-Cache + */ +int __cifs_readpage_from_fscache(struct inode *inode, struct page *page) +{ + int ret; + + cFYI(1, "CIFS: readpage_from_fscache(fsc:%p, p:%p, i:0x%p", + CIFS_I(inode)->fscache, page, inode); + ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page, + cifs_readpage_from_fscache_complete, + NULL, + GFP_KERNEL); + switch (ret) { + + case 0: /* page found in fscache, read submitted */ + cFYI(1, "CIFS: readpage_from_fscache: submitted"); + return ret; + case -ENOBUFS: /* page won't be cached */ + case -ENODATA: /* page not in cache */ + cFYI(1, "CIFS: readpage_from_fscache %d", ret); + return 1; + + default: + cERROR(1, "unknown error ret = %d", ret); + } + return ret; +} + +/* + * Retrieve a set of pages from FS-Cache + */ +int __cifs_readpages_from_fscache(struct inode *inode, + struct address_space *mapping, + struct list_head *pages, + unsigned *nr_pages) +{ + int ret; + + cFYI(1, "CIFS: __cifs_readpages_from_fscache (0x%p/%u/0x%p)", + CIFS_I(inode)->fscache, *nr_pages, inode); + ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping, + pages, nr_pages, + cifs_readpage_from_fscache_complete, + NULL, + mapping_gfp_mask(mapping)); + switch (ret) { + case 0: /* read submitted to the cache for all pages */ + cFYI(1, "CIFS: readpages_from_fscache: submitted"); + return ret; + + case -ENOBUFS: /* some pages are not cached and can't be */ + case -ENODATA: /* some pages are not cached */ + cFYI(1, "CIFS: readpages_from_fscache: no page"); + return 1; + + default: + cFYI(1, "unknown error ret = %d", ret); + } + + return ret; +} + void __cifs_readpage_to_fscache(struct inode *inode, struct page *page) { int ret; Index: cifs-2.6/fs/cifs/fscache.h =================================================================== --- cifs-2.6.orig/fs/cifs/fscache.h +++ cifs-2.6/fs/cifs/fscache.h @@ -32,7 +32,6 @@ extern const struct fscache_cookie_def c extern const struct fscache_cookie_def cifs_fscache_super_index_def; extern const struct fscache_cookie_def cifs_fscache_inode_object_def; - extern int cifs_fscache_register(void); extern void cifs_fscache_unregister(void); @@ -50,6 +49,11 @@ extern void cifs_fscache_reset_inode_coo extern void __cifs_fscache_invalidate_page(struct page *, struct inode *); extern int cifs_fscache_release_page(struct page *page, gfp_t gfp); +extern int __cifs_readpage_from_fscache(struct inode *, struct page *); +extern int __cifs_readpages_from_fscache(struct inode *, + struct address_space *, + struct list_head *, + unsigned *); extern void __cifs_readpage_to_fscache(struct inode *, struct page *); @@ -60,6 +64,26 @@ static inline void cifs_fscache_invalida __cifs_fscache_invalidate_page(page, inode); } +static inline int cifs_readpage_from_fscache(struct inode *inode, + struct page *page) +{ + if (CIFS_I(inode)->fscache) + return __cifs_readpage_from_fscache(inode, page); + + return -ENOBUFS; +} + +static inline int cifs_readpages_from_fscache(struct inode *inode, + struct address_space *mapping, + struct list_head *pages, + unsigned *nr_pages) +{ + if (CIFS_I(inode)->fscache) + return __cifs_readpages_from_fscache(inode, mapping, pages, + nr_pages); + return -ENOBUFS; +} + static inline void cifs_readpage_to_fscache(struct inode *inode, struct page *page) { @@ -90,6 +114,20 @@ static inline void cifs_fscache_release_ static inline int cifs_fscache_invalidate_page(struct page *page, struct inode *) {} +static inline int +cifs_readpage_from_fscache(struct inode *inode, struct page *page) +{ + return -ENOBUFS; +} + +static inline int cifs_readpages_from_fscache(struct inode *inode, + struct address_space *mapping, + struct list_head *pages, + unsigned *nr_pages) +{ + return -ENOBUFS; +} + static inline void cifs_readpage_to_fscache(struct inode *inode, struct page *page) {}