[PATCH 1/8] quota: clean out speculative preallocations when checking quota usage

["Darrick J. Wong" <darrick.wong@oracle.com>]

From: Darrick J. Wong <darrick.wong@oracle.com>

On XFS, the only reliable way to clean out speculative post-eof
preallocations, delayed allocations, and speculative cow preallocations
is to cycle the filesystem mount.  Since we're comparing the post-test
quota counts against a freshly quotacheck to look for leaks, it's fine
to cycle the mount.  This eliminates sporadic quota count failures when
running xfstests with quotas enabled.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 common/quota |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)


diff --git a/common/quota b/common/quota
index 993ff5de..9309e786 100644
--- a/common/quota
+++ b/common/quota
@@ -260,10 +260,10 @@ _check_quota_usage()
 		quotaon -f -u -g $SCRATCH_MNT 2>/dev/null
 		;;
 	xfs)
-		# Clear out speculative preallocations to eliminate them
-		# as a source of intermittent orig/checked differences.
-		test -x "$XFS_SPACEMAN_PROG" && \
-			"$XFS_SPACEMAN_PROG" -c 'prealloc -s' $SCRATCH_MNT
+		# Only way to make this reliable with cow/delalloc/speculative
+		# preallocations is to unmount and remount the whole mess...
+		_scratch_unmount
+		_scratch_mount "-o usrquota,grpquota"
 		;;
 	*)
 		;;