[PATCH 3.16.y-ckt 028/165] xfs: Fix quota type in quota structures when reusing quota file

[Luis Henriques]

3.16.7-ckt9 -stable review patch.  If anyone has any objections, please let me know.

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

From: Jan Kara <jack at suse.cz>

commit dfcc70a8c868fe03276fa59864149708fb41930b upstream.

For filesystems without separate project quota inode field in the
superblock we just reuse project quota file for group quotas (and vice
versa) if project quota file is allocated and we need group quota file.
When we reuse the file, quota structures on disk suddenly have wrong
type stored in d_flags though. Nobody really cares about this (although
structure type reported to userspace was wrong as well) except
that after commit 14bf61ffe6ac (quota: Switch ->get_dqblk() and
->set_dqblk() to use bytes as space units) assertion in
xfs_qm_scall_getquota() started to trigger on xfs/106 test (apparently I
was testing without XFS_DEBUG so I didn't notice when submitting the
above commit).

Fix the problem by properly resetting ddq->d_flags when running quotacheck
for a quota file.

Reported-by: Al Viro <viro at ZenIV.linux.org.uk>
Signed-off-by: Jan Kara <jack at suse.cz>
Reviewed-by: Dave Chinner <dchinner at redhat.com>
Signed-off-by: Dave Chinner <david at fromorbit.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/xfs/xfs_qm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 6c51e2f97c0a..7347df393225 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -937,6 +937,11 @@ xfs_qm_reset_dqcounts(
 		 */
 		xfs_dqcheck(mp, ddq, id+j, type, XFS_QMOPT_DQREPAIR,
 			    "xfs_quotacheck");
+		/*
+		 * Reset type in case we are reusing group quota file for
+		 * project quotas or vice versa
+		 */
+		ddq->d_flags = type;
 		ddq->d_bcount = 0;
 		ddq->d_icount = 0;
 		ddq->d_rtbcount = 0;