From: Josef Bacik Date: Mon, 7 Oct 2019 19:33:39 +0000 (-0400) Subject: btrfs: add a test for multi-subvolume fsyncing X-Git-Tag: v2022.05.01~1005 X-Git-Url: http://git.apps.os.sepia.ceph.com/?p=xfstests-dev.git;a=commitdiff_plain;h=17c22e556f8fedfc45511c526ca0d5db6daf76b6 btrfs: add a test for multi-subvolume fsyncing I discovered a problem in btrfs where we'd end up pointing at a block we hadn't written out yet. This is triggered by a race when two different files on two different subvolumes fsync. This test exercises this path with dm-log-writes, and then replays the log at every FUA to verify the file system is still mountable and the log is replayable. This test is to verify the fix btrfs: fix incorrect updating of log root tree actually fixed the problem. Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Signed-off-by: Eryu Guan --- diff --git a/tests/btrfs/196 b/tests/btrfs/196 new file mode 100755 index 00000000..9a3435d5 --- /dev/null +++ b/tests/btrfs/196 @@ -0,0 +1,110 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2019 Facebook. All Rights Reserved. +# +# FS QA Test 196 +# +# Test multi subvolume fsync to test a bug where we'd end up pointing at a block +# we haven't written. This was fixed by the patch +# +# btrfs: fix incorrect updating of log root tree +# +# Will do log replay and check the filesystem. +# +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" + +here=`pwd` +tmp=/tmp/$$ +fio_config=$tmp.fio +status=1 # failure is the default! +trap "_cleanup; exit \$status" 0 1 2 3 15 + +_cleanup() +{ + cd / + _log_writes_cleanup &> /dev/null + _dmthin_cleanup + rm -f $tmp.* +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter +. ./common/dmthin +. ./common/dmlogwrites + +# remove previous $seqres.full before test +rm -f $seqres.full + +# real QA test starts here + +# Modify as appropriate. +_supported_fs btrfs +_supported_os Linux + +# Use thin device as replay device, which requires $SCRATCH_DEV +_require_scratch_nocheck +# and we need extra device as log device +_require_log_writes +_require_dm_target thin-pool + +cat >$fio_config <> $fio_config + echo "filename=$SCRATCH_MNT/$i/file" >> $fio_config +done + +_require_fio $fio_config + +cat $fio_config >> $seqres.full + +# Use a thin device to provide deterministic discard behavior. Discards are used +# by the log replay tool for fast zeroing to prevent out-of-order replay issues. +_dmthin_init +_log_writes_init $DMTHIN_VOL_DEV +_log_writes_mkfs >> $seqres.full 2>&1 +_log_writes_mark mkfs + +_log_writes_mount + +# First create all the subvolumes +for i in $(seq 0 49); do + $BTRFS_UTIL_PROG subvolume create "$SCRATCH_MNT/$i" > /dev/null +done + +$FIO_PROG $fio_config > /dev/null 2>&1 +_log_writes_unmount + +_log_writes_remove +prev=$(_log_writes_mark_to_entry_number mkfs) +[ -z "$prev" ] && _fail "failed to locate entry mark 'mkfs'" +cur=$(_log_writes_find_next_fua $prev) +[ -z "$cur" ] && _fail "failed to locate next FUA write" + +while [ ! -z "$cur" ]; do + _log_writes_replay_log_range $cur $DMTHIN_VOL_DEV >> $seqres.full + + # We need to mount the fs because btrfsck won't bother checking the log. + _dmthin_mount + _dmthin_check_fs + + prev=$cur + cur=$(_log_writes_find_next_fua $(($cur + 1))) + [ -z "$cur" ] && break +done + +echo "Silence is golden" + +# success, all done +status=0 +exit diff --git a/tests/btrfs/196.out b/tests/btrfs/196.out new file mode 100644 index 00000000..477dcf02 --- /dev/null +++ b/tests/btrfs/196.out @@ -0,0 +1,2 @@ +QA output created by 196 +Silence is golden diff --git a/tests/btrfs/group b/tests/btrfs/group index 3ce6fa46..c2ab3e7d 100644 --- a/tests/btrfs/group +++ b/tests/btrfs/group @@ -198,3 +198,4 @@ 193 auto quick qgroup enospc limit 194 auto volume 195 auto volume +196 auto metadata log volume