ext4: Fix lock inversion in ext4_ext_truncate() From: Jan Kara We cannot call ext4_orphan_add() from under i_data_sem because that causes a lock ordering violation between i_data_sem and and the superblock lock. Updated with Aneesh's locking order fix Signed-off-by: Jan Kara Signed-off-by: Mingming Cao Signed-off-by: Aneesh Kumar K.V Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) Index: linux-2.6.26-rc9/fs/ext4/extents.c =================================================================== --- linux-2.6.26-rc9.orig/fs/ext4/extents.c 2008-07-11 16:05:09.000000000 -0700 +++ linux-2.6.26-rc9/fs/ext4/extents.c 2008-07-11 16:05:09.000000000 -0700 @@ -2768,6 +2768,9 @@ void ext4_ext_truncate(struct inode *ino if (inode->i_size & (sb->s_blocksize - 1)) ext4_block_truncate_page(handle, mapping, inode->i_size); + if (ext4_orphan_add(handle, inode)) + goto out_stop; + down_write(&EXT4_I(inode)->i_data_sem); ext4_ext_invalidate_cache(inode); @@ -2778,8 +2781,6 @@ void ext4_ext_truncate(struct inode *ino * Probably we need not scan at all, * because page truncation is enough. */ - if (ext4_orphan_add(handle, inode)) - goto out_stop; /* we have to know where to truncate from in crash case */ EXT4_I(inode)->i_disksize = inode->i_size; @@ -2796,6 +2797,7 @@ void ext4_ext_truncate(struct inode *ino handle->h_sync = 1; out_stop: + up_write(&EXT4_I(inode)->i_data_sem); /* * If this was a simple ftruncate() and the file will remain alive, * then we need to clear up the orphan record which we created above. @@ -2806,7 +2808,6 @@ out_stop: if (inode->i_nlink) ext4_orphan_del(handle, inode); - up_write(&EXT4_I(inode)->i_data_sem); inode->i_mtime = inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle);