[PATCH 3.2 052/106] ext4: fix fdatasync(2) after extent manipulation operations

[Ben Hutchings]

3.2.93-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Jan Kara <j...@suse.cz>

commit 67a7d5f561f469ad2fa5154d2888258ab8e6df7c upstream.

Currently, extent manipulation operations such as hole punch, range
zeroing, or extent shifting do not record the fact that file data has
changed and thus fdatasync(2) has a work to do. As a result if we crash
e.g. after a punch hole and fdatasync, user can still possibly see the
punched out data after journal replay. Test generic/392 fails due to
these problems.

Fix the problem by properly marking that file data has changed in these
operations.

Fixes: a4bb6b64e39abc0e41ca077725f2a72c868e7622
Signed-off-by: Jan Kara <j...@suse.cz>
Signed-off-by: Theodore Ts'o <ty...@mit.edu>
[bwh: Backported to 3.2: Only the punch-hole operation is supported, and
 it's in extents.c.]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5023,6 +5023,8 @@ out:
        ext4_orphan_del(handle, inode);
        inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
        ext4_mark_inode_dirty(handle, inode);
+       if (err >= 0)
+               ext4_update_inode_fsync_trans(handle, inode, 1);
        ext4_journal_stop(handle);
        return err;
 }