generic: busy loop of dd and rm test

Add a case for testing whether writing failed on NO_SPACE in a busy
loop of write and delete when disk almost full.  It is a long-term
problem since very beginning in btrfs, and has been fixed by
patchset titled "btrfs: Fix no_space on dd and rm loop" from
zhaolei@cn.fujitsu.com.

Signed-off-by: Wang Yanfeng <wangyf-fnst@cn.fujitsu.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

tests/generic/102

@@ -0,0 +1,65 @@
+#! /bin/bash
+# FS QA Test No. 102
+#
+# TEST busy loop of write and delete in a filesystem.
+# Sometimes writes will failed on NO_SPACE when disk almost full
+# in btrfs. It is long-term problem since very beginning for btrfs
+#
+# This issue was fixed by the patchset named:
+#
+# btrfs: Fix no_space on dd and rm loop < from zhaolei@cn.fujitsu.com >
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2015 Fujitsu.  All Rights Reserved.
+# Author: Wang Yanfeng <wangyf-fnst@cn.fujitsu.com>
+#
+# 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"
+
+tmp=/tmp/$$
+status=1
+trap "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 generic
+_supported_os Linux
+_require_scratch
+
+rm -f $seqres.full
+
+dev_size=$((512 * 1024 * 1024))     # 512MB filesystem
+_scratch_mkfs_sized $dev_size >>$seqres.full 2>&1
+_scratch_mount
+
+for ((i = 0; i < 10; i++)); do
+	echo "loop $i" >>$seqres.full
+
+	$XFS_IO_PROG -f -c "pwrite -b 1m 0 400m" "$SCRATCH_MNT"/file | \
+_filter_xfs_io | _filter_scratch
+
+	rm -f "$SCRATCH_MNT"/file
+done
+
+status=0
+exit

tests/generic/102.out

@@ -0,0 +1,21 @@
+QA output created by 102
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 419430400/419430400 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

tests/generic/group

@@ -104,6 +104,7 @@
 099 udf auto
 100 udf auto
 101 auto quick metadata
+102 auto rw
 105 acl auto quick
 112 rw aio auto quick
 113 rw aio auto quick