At 11/08/2016 06:58 PM, Eryu Guan wrote:
On Tue, Nov 08, 2016 at 05:15:15PM +0800, Qu Wenruo wrote:
Due to the fact that btrfs uses different max extent size for
compressed and non-compressed write, it calculates metadata reservation
incorrectly.
This can leads to false ENOSPC alert for compressed write.
This test case will check it by using small fs and large nodesize, and
do parallel compressed write to trigger it.
The fix is not merged and may change in the future, but the function is
good enough:
btrfs: improve inode's outstanding_extents computation
btrfs: fix false enospc for compression
Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
---
tests/btrfs/132 | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/btrfs/132.out | 2 ++
tests/btrfs/group | 1 +
3 files changed, 92 insertions(+)
create mode 100755 tests/btrfs/132
create mode 100644 tests/btrfs/132.out
diff --git a/tests/btrfs/132 b/tests/btrfs/132
new file mode 100755
index 0000000..95c21ea
--- /dev/null
+++ b/tests/btrfs/132
@@ -0,0 +1,89 @@
+#! /bin/bash
+# FS QA Test 132
+#
+# Check if false ENOSPC will happen when parallel buffer write happens
+# The problem is caused by incorrect metadata reservation.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2016 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!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+ cd /
+ rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+
+# Use small filesystem with maximum nodesize.
+# Since the false ENOSPC happens due to incorrect metadata reservation,
+# larger nodesize and small fs will make it much easier to reproduce
+_scratch_mkfs -b 512M -n 64k >> $seqres.full 2>&1
How about override MKFS_OPTIONS and call _scratch_mkfs_sized? e.g.
export MKFS_OPTIONS="-n 64k"
_scratch_mkfs_sized $((512 * 1024 * 1024))
Overriding MKFS_OPTIONS makes us unable to parse more mkfs options, for
example to test some incompatible features.
So I'd just parse this mkfs options as extra options.
+_scratch_mount "-o compress"
+
+sleep_time=$(($TIME_FACTOR * 15))
+loop_writer()
+{
+ offset=$1
+ len=$2
+ file=$3
+
+ while true;
+ do
+ # Only need stderr, and we need to specify small block size
+ # but still trigger compression
+ xfs_io -c "pwrite -b 8K $offset $len" $file 2>&1 > /dev/null
Use $XFS_IO_PROG here.
Oh, I forgot it again...
+ done
+}
+
+touch $SCRATCH_MNT/testfile
+
+# Start 2 writter writting into the same file
+# The file is 142M, which is smaller than 1/2 of the filesystem,
+# so no other cause can lead to ENOSPC.
+loop_writer 0 128M $SCRATCH_MNT/testfile &
+loop_writer 128M 16M $SCRATCH_MNT/testfile &
+
+sleep $sleep_time
+
+kill 0
+sleep
Oh, I thought I typed "wait" not "sleep".
This is not working for me, even I removed the suspicious "sleep", seems
"132" itself was killed too.
I'd save pids of background jobs and kill the pids and call wait to make
sure all child processes exit running. e.g.
loop_writer ... &
pids=$!
loop_writer ... &
pids="$pids $!"
sleep $sleep_time
kill $pids
wait
And you're missing 'echo "Silence is golden"' in the test.
I'll update them soon.
Thanks,
Qu
Thanks,
Eryu
+
+status=0
+exit
diff --git a/tests/btrfs/132.out b/tests/btrfs/132.out
new file mode 100644
index 0000000..b096312
--- /dev/null
+++ b/tests/btrfs/132.out
@@ -0,0 +1,2 @@
+QA output created by 132
+Silence is golden
diff --git a/tests/btrfs/group b/tests/btrfs/group
index c090604..ec8ad80 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -134,3 +134,4 @@
129 auto quick send
130 auto clone send
131 auto quick
+132 auto compress
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe fstests" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe fstests" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
