xfs: preserve default grace interval during quotacheck

commit 1ec547b0734fdf924291b90c17add3da78c2addf upstream.

When quotacheck runs, it zeroes all the timer fields in every dquot.
Unfortunately, it also does this to the root dquot, which erases any
preconfigured grace intervals and warning limits that the administrator
may have set.  Worse yet, the incore copies of those variables remain
set.  This cache coherence problem manifests itself as the grace
interval mysteriously being reset back to the defaults at the /next/
mount.

Fix it by not resetting the root disk dquot's timer and warning fields.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 035930a4f0dd85eed1e2e7765978f7742f3c6b45..fe93e044d81ba03f264f0108823fdd583e06cc18 100644 (file)
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -875,12 +875,20 @@ xfs_qm_reset_dqcounts(
                ddq->d_bcount = 0;
                ddq->d_icount = 0;
                ddq->d_rtbcount = 0;
-               ddq->d_btimer = 0;
-               ddq->d_itimer = 0;
-               ddq->d_rtbtimer = 0;
-               ddq->d_bwarns = 0;
-               ddq->d_iwarns = 0;
-               ddq->d_rtbwarns = 0;
+
+               /*
+                * dquot id 0 stores the default grace period and the maximum
+                * warning limit that were set by the administrator, so we
+                * should not reset them.
+                */
+               if (ddq->d_id != 0) {
+                       ddq->d_btimer = 0;
+                       ddq->d_itimer = 0;
+                       ddq->d_rtbtimer = 0;
+                       ddq->d_bwarns = 0;
+                       ddq->d_iwarns = 0;
+                       ddq->d_rtbwarns = 0;
+               }
 
                if (xfs_sb_version_hascrc(&mp->m_sb)) {
                        xfs_update_cksum((char *)&dqb[j],