[PATCH] fstests: fix btrfs/255 to fail on deadlock

[Gabriel Niebler <gniebler@suse.com>]

In its current implementation, the test btrfs/255 would hang forever
on any kernel w/o patch "btrfs: fix deadlock between quota disable
and qgroup rescan worker", rather than failing, as it should.
Fix this by introducing generous timeouts.

Signed-off-by: Gabriel Niebler <gniebler@suse.com>
---
 tests/btrfs/255 | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/tests/btrfs/255 b/tests/btrfs/255
index 7e70944a..4c779458 100755
--- a/tests/btrfs/255
+++ b/tests/btrfs/255
@@ -14,6 +14,7 @@ _begin_fstest auto qgroup balance
 
 # real QA test starts here
 _supported_fs btrfs
+_require_command "$TIMEOUT_PROG" timeout
 _require_scratch
 
 _scratch_mkfs >> $seqres.full 2>&1
@@ -37,15 +38,23 @@ done
 _btrfs_stress_balance $SCRATCH_MNT >> $seqres.full &
 balance_pid=$!
 echo $balance_pid >> $seqres.full
+timeout=$((30 * 60))
 for ((i = 0; i < 20; i++)); do
-	$BTRFS_UTIL_PROG quota enable $SCRATCH_MNT
-	$BTRFS_UTIL_PROG quota disable $SCRATCH_MNT
+	$TIMEOUT_PROG -s KILL ${timeout}s $BTRFS_UTIL_PROG quota enable $SCRATCH_MNT
+	[ $? -eq 0 ] || _fail "quota enable timed out"
+	$TIMEOUT_PROG -s KILL ${timeout}s $BTRFS_UTIL_PROG quota disable $SCRATCH_MNT
+	[ $? -eq 0 ] || _fail "quota disable timed out"
 done
 kill $balance_pid &> /dev/null
-wait
+
 # wait for the balance operation to finish
+elapsed=0
 while ps aux | grep "balance start" | grep -qv grep; do
+	if [ $elapsed -gt $timeout ]; then
+		_fail "balance not finished after $timeout seconds"
+	fi
 	sleep 1
+	elapsed=$(( ++elapsed ))
 done
 
 echo "Silence is golden"
-- 
2.35.1