[PATCH v2] btrfs: add regression test for remount with thread_pool resized

[Xing Gu <gux.fnst@cn.fujitsu.com>]

Regression test for a btrfs issue of resizing 'thread_pool'
when remount the fs.

Signed-off-by: Xing Gu <gux.fnst@cn.fujitsu.com>
---
 tests/btrfs/017     | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/017.out |  1 +
 tests/btrfs/group   |  1 +
 3 files changed, 66 insertions(+)
 create mode 100755 tests/btrfs/017
 create mode 100644 tests/btrfs/017.out

diff --git a/tests/btrfs/017 b/tests/btrfs/017
new file mode 100755
index 0000000..81f5af6
--- /dev/null
+++ b/tests/btrfs/017
@@ -0,0 +1,64 @@
+#!/bin/bash
+# FS QA Test No. btrfs/017
+#
+# Regression test for a btrfs issue of resizing 'thread_pool' when
+# remount the fs.
+# This was fixed in the following linux kernel patch:
+#     800ee22 btrfs: fix crash in remount(thread_pool=) case
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2014 Fujitsu.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+_cleanup()
+{
+    rm -f $tmp.*
+}
+
+trap "_cleanup ; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+
+_scratch_mkfs > /dev/null
+
+dmesg -c > /dev/null
+nr_null=`dmesg | grep -c "kernel NULL pointer dereference"`
+_scratch_mount "-o thread_pool=6"
+_scratch_mount "-o remount,thread_pool=10"
+new_null=`dmesg | grep -c "kernel NULL pointer dereference"`
+if [ $new_null -ne $nr_null ]; then
+	_fatal "kernel bug detected, check dmesg for more infomation."
+fi
+
+status=0
+exit
diff --git a/tests/btrfs/017.out b/tests/btrfs/017.out
new file mode 100644
index 0000000..90c4b69
--- /dev/null
+++ b/tests/btrfs/017.out
@@ -0,0 +1 @@
+QA output created by 017
diff --git a/tests/btrfs/group b/tests/btrfs/group
index abb2fe4..cd553a3 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -19,6 +19,7 @@
 014 auto balance
 015 auto quick snapshot
 016 auto quick send
+017 auto quick
 018 auto quick subvol
 019 auto quick send
 020 auto quick replace
-- 
1.9.3