[PATCH] xfs/220: fix quotarm syscall test

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

In commit 6ba125c9, we tried to adjust this fstest to deal with the
removal of the ability to turn off quota accounting via the Q_XQUOTAOFF
system call.

Unfortunately, the changes made to this test make it nonfunctional on
those newer kernels, since the Q_XQUOTARM command returns EINVAL if
quota accounting is turned on, and the changes filter out the EINVAL
error string.

Doing this wasn't /incorrect/, because, very narrowly speaking, the
intent of this test is to guard against Q_XQUOTARM returning ENOSYS when
quota has been enabled.  However, this also means that we no longer test
Q_XQUOTARM's ability to truncate the quota files at all.

So, fix this test to deal with the loss of quotaoff in the same way that
the others do -- if accounting is still enabled after the 'off' command,
cycle the mount so that Q_XQUOTARM actually truncates the files.

While we're at it, enhance the test to check that XQUOTARM actually
truncated the quota files.

Fixes: 6ba125c9 ("xfs/220: avoid failure when disabling quota accounting is not supported")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 tests/xfs/220 |   28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/tests/xfs/220 b/tests/xfs/220
index 241a7abd..cfa90d3a 100755
--- a/tests/xfs/220
+++ b/tests/xfs/220
@@ -52,14 +52,28 @@ _scratch_mkfs_xfs >/dev/null 2>&1
 # mount  with quotas enabled
 _scratch_mount -o uquota
 
-# turn off quota and remove space allocated to the quota files
+# turn off quota accounting...
+$XFS_QUOTA_PROG -x -c off $SCRATCH_DEV
+
+# ...but if the kernel doesn't support turning off accounting, remount with
+# noquota option to turn it off...
+if $XFS_QUOTA_PROG -x -c 'state -u' $SCRATCH_DEV | grep -q 'Accounting: ON'; then
+	_scratch_unmount
+	_scratch_mount -o noquota
+fi
+
+before_freesp=$(_get_available_space $SCRATCH_MNT)
+
+# ...and remove space allocated to the quota files
 # (this used to give wrong ENOSYS returns in 2.6.31)
-#
-# The sed expression below replaces a notrun to cater for kernels that have
-# removed the ability to disable quota accounting at runtime.  On those
-# kernel this test is rather useless, and in a few years we can drop it.
-$XFS_QUOTA_PROG -x -c off -c remove $SCRATCH_DEV 2>&1 | \
-	sed -e '/XFS_QUOTARM: Invalid argument/d'
+$XFS_QUOTA_PROG -x -c remove $SCRATCH_DEV
+
+# Make sure we actually freed the space used by dquot 0
+after_freesp=$(_get_available_space $SCRATCH_MNT)
+if [ $before_freesp -ge $after_freesp ]; then
+	echo "before: $before_freesp; after: $after_freesp" >> $seqres.full
+	echo "expected more free space after Q_XQUOTARM"
+fi
 
 # and unmount again
 _scratch_unmount