btrfs: add qgroup rescan stress test

Test flow is to run fsstress after triggering quota rescan.
the ruler is simple, we just remove all files and directories,
sync filesystem and see if qgroup's ref and excl are nodesize.

Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

tests/btrfs/057

@@ -0,0 +1,81 @@
+#! /bin/bash
+# FSQA Test No. btrfs/057
+#
+# Quota rescan stress test, we run fsstress and quota rescan concurrently
+#
+#-----------------------------------------------------------------------
+# 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
+
+_cleanup()
+{
+	cd /
+	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
+_need_to_be_root
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+
+rm -f $seqres.full
+
+# use small leaf size to get higher btree height.
+run_check _scratch_mkfs "-b 1g --nodesize 4096"
+
+# inode cache is saved in the FS tree itself for every
+# individual FS tree,that affects the sizes reported by qgroup show
+# so we need to explicitly turn it off to get consistent values.
+run_check _scratch_mount "-o noinode_cache"
+
+# -w ensures that the only ops are ones which cause write I/O
+run_check $FSSTRESS_PROG -d $SCRATCH_MNT -w -p 5 -n 1000 \
+		$FSSTRESS_AVOID >&/dev/null
+
+_run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT \
+	$SCRATCH_MNT/snap1
+
+run_check $FSSTRESS_PROG -d $SCRATCH_MNT/snap1 -w -p 5 -n 1000 \
+       $FSSTRESS_AVOID >&/dev/null
+
+_run_btrfs_util_prog quota enable $SCRATCH_MNT
+_run_btrfs_util_prog quota rescan -w $SCRATCH_MNT
+
+# ignore removing subvolume errors
+rm -rf $SCRATCH_MNT/* >& /dev/null
+
+_run_btrfs_util_prog filesystem sync $SCRATCH_MNT
+$BTRFS_UTIL_PROG qgroup show $SCRATCH_MNT | $SED_PROG -n '/[0-9]/p' \
+	| $AWK_PROG '{print $2" "$3}'
+
+status=0
+exit

tests/btrfs/057.out

@@ -0,0 +1,3 @@
+QA output created by 057
+4096 4096
+4096 4096

tests/btrfs/group

@@ -59,3 +59,4 @@
 054 auto quick
 055 auto quick
 056 auto quick
+057 auto quick