ext4: Fix fsync error handling after filesystem abort
If filesystem was aborted after inode's write back is complete
but before its metadata was updated we may return success
results in data loss.
In order to handle fs abort correctly we have to check
fs state once we discover that it is in MS_RDONLY state
Test case: http://patchwork.ozlabs.org/patch/244297
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index fc938eb..a8bc47f 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -98,8 +98,13 @@
trace_ext4_sync_file_enter(file, datasync);
- if (inode->i_sb->s_flags & MS_RDONLY)
+ if (inode->i_sb->s_flags & MS_RDONLY) {
+ /* Make sure that we read updated s_mount_flags value */
+ smp_rmb();
+ if (EXT4_SB(inode->i_sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
+ ret = -EROFS;
goto out;
+ }
if (!journal) {
ret = generic_file_fsync(file, start, end, datasync);