From de14569f94513279e3d44d9571a421e9da1759ae Mon Sep 17 00:00:00 2001 From: Vladimir Saveliev Date: Mon, 22 Jan 2007 20:40:46 -0800 Subject: [PATCH] resierfs: avoid tail packing if an inode was ever mmapped This patch fixes a confusion reiserfs has for a long time. On release file operation reiserfs used to try to pack file data stored in last incomplete page of some files into metadata blocks. After packing the page got cleared with clear_page_dirty. It did not take into account that the page may be mmaped into other process's address space. Recent replacement for clear_page_dirty cancel_dirty_page found the confusion with sanity check that page has to be not mapped. The patch fixes the confusion by making reiserfs avoid tail packing if an inode was ever mmapped. reiserfs_mmap and reiserfs_file_release are serialized with mutex in reiserfs specific inode. reiserfs_mmap locks the mutex and sets a bit in reiserfs specific inode flags. reiserfs_file_release checks the bit having the mutex locked. If bit is set - tail packing is avoided. This eliminates a possibility that mmapped page gets cancel_page_dirty-ed. Signed-off-by: Vladimir Saveliev Cc: Jeff Mahoney Cc: Chris Mason Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/reiserfs/file.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'fs/reiserfs/file.c') diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c index 99b6f329ba2..5109f1d5e7f 100644 --- a/fs/reiserfs/file.c +++ b/fs/reiserfs/file.c @@ -48,6 +48,11 @@ static int reiserfs_file_release(struct inode *inode, struct file *filp) } mutex_lock(&inode->i_mutex); + + mutex_lock(&(REISERFS_I(inode)->i_mmap)); + if (REISERFS_I(inode)->i_flags & i_ever_mapped) + REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask; + reiserfs_write_lock(inode->i_sb); /* freeing preallocation only involves relogging blocks that * are already in the current transaction. preallocation gets @@ -100,11 +105,24 @@ static int reiserfs_file_release(struct inode *inode, struct file *filp) err = reiserfs_truncate_file(inode, 0); } out: + mutex_unlock(&(REISERFS_I(inode)->i_mmap)); mutex_unlock(&inode->i_mutex); reiserfs_write_unlock(inode->i_sb); return err; } +static int reiserfs_file_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct inode *inode; + + inode = file->f_path.dentry->d_inode; + mutex_lock(&(REISERFS_I(inode)->i_mmap)); + REISERFS_I(inode)->i_flags |= i_ever_mapped; + mutex_unlock(&(REISERFS_I(inode)->i_mmap)); + + return generic_file_mmap(file, vma); +} + static void reiserfs_vfs_truncate_file(struct inode *inode) { reiserfs_truncate_file(inode, 1); @@ -1527,7 +1545,7 @@ const struct file_operations reiserfs_file_operations = { #ifdef CONFIG_COMPAT .compat_ioctl = reiserfs_compat_ioctl, #endif - .mmap = generic_file_mmap, + .mmap = reiserfs_file_mmap, .open = generic_file_open, .release = reiserfs_file_release, .fsync = reiserfs_sync_file, -- cgit v1.2.3