btrfs: add test for enable/disable quota and create/destroy qgroup repeatedly

Test enable/disable quota and create/destroy qgroup repeatedly in
parallel and confirm it does not cause kernel hang. It only happens
in kernel staring with kernel 5.17-rc3. This is a regression test
for the problem reported to linux-btrfs list [1].

The hang was recreated using the test case and fixed by kernel patch
titled

  btrfs: qgroup: fix deadlock between rescan worker and remove qgroup

[1] https://lore.kernel.org/linux-btrfs/20220228014340.21309-1-realwakka@gmail.com/

Signed-off-by: Sidong Yang <realwakka@gmail.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

diff --git a/tests/btrfs/262 b/tests/btrfs/262
new file mode 100755 (executable)
index 0000000..d58afa4
--- /dev/null
+++ b/tests/btrfs/262
@@ -0,0 +1,38 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2022 Sidong Yang.  All Rights Reserved.
+#
+# FS QA Test 262
+#
+# Test that running qgroup enable, create, destroy, and disable commands in
+# parallel doesn't result in a deadlock, a crash or any filesystem
+# inconsistency.
+#
+. ./common/preamble
+_begin_fstest auto quick qgroup
+
+# Import common functions.
+. ./common/filter
+
+# real QA test starts here
+
+_supported_fs btrfs
+
+_require_scratch
+
+_scratch_mkfs > /dev/null 2>&1
+_scratch_mount
+
+for ((i = 0; i < 200; i++)); do
+       $BTRFS_UTIL_PROG quota enable $SCRATCH_MNT 2>> $seqres.full &
+       $BTRFS_UTIL_PROG qgroup create 1/0 $SCRATCH_MNT 2>> $seqres.full &
+       $BTRFS_UTIL_PROG qgroup destroy 1/0 $SCRATCH_MNT 2>> $seqres.full &
+       $BTRFS_UTIL_PROG quota disable $SCRATCH_MNT 2>> $seqres.full &
+done
+
+wait
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit

diff --git a/tests/btrfs/262.out b/tests/btrfs/262.out
new file mode 100644 (file)
index 0000000..404badc
--- /dev/null
+++ b/tests/btrfs/262.out
@@ -0,0 +1,2 @@
+QA output created by 262
+Silence is golden