Re: [PATCH v2] tests/generic: test xfs log recovery metadata LSN ordering

Eryu Guan
2016-08-15T12:29:39Z

On Mon, Aug 15, 2016 at 08:05:44AM -0400, Brian Foster wrote:
> XFS had a bug that lead to a possible out-of-order log recovery
> situation (e.g., replay a stale modification from the log over more
> recent metadata in destination buffer). This resulted in false
> corruption reports during log recovery and thus mount failure.
>
> This condition is caused by system crash or filesystem shutdown shortly
> after a successful log recovery. Add a test to run a combined workload,
> fs shutdown and log recovery loop known to reproduce the problem on
> affected kernels.
>
> Signed-off-by: Brian Foster <bfoster@redhat.com>
> ---
>
> v2:
> - Use $KILLALL_PROG for killall command.
> - Convert to generic test.
> v1: http://marc.info/?l=linux-xfs&m=147100402211629&w=2
>
> tests/generic/999 | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++
> tests/generic/999.out | 2 ++
> tests/generic/group | 1 +
> 3 files changed, 91 insertions(+)
> create mode 100755 tests/generic/999
> create mode 100644 tests/generic/999.out
>
> diff --git a/tests/generic/999 b/tests/generic/999
> new file mode 100755
> index 0000000..f3257e4
> --- /dev/null
> +++ b/tests/generic/999
> @@ -0,0 +1,88 @@
> +#! /bin/bash
> +# FS QA Test No. 999
> +#
> +# Test XFS log recovery ordering on v5 superblock filesystems. XFS had a problem
> +# where it would incorrectly replay older modifications from the log over more
> +# recent versions of metadata due to failure to update metadata LSNs during log
> +# recovery. This could result in false positive reports of corruption during log
> +# recovery and permanent mount failure.
> +#
> +# To test this situation, run frequent shutdowns immediately after log recovery.
> +# Ensure that log recovery does not recover stale modifications and cause
> +# spurious corruption reports and/or mount failures.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2016 Red Hat, Inc. 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.*
> + $KILLALL_PROG -9 fsstress > /dev/null 2>&1
> + _scratch_unmount > /dev/null 2>&1
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +
> +# Modify as appropriate.
> +_supported_fs xfs

"xfs" should be "generic"?

> +_supported_os Linux
> +
> +_require_scratch

Missed a "_require_scratch_shutdown"?

> +_require_command "$KILLALL_PROG"
> +
> +rm -f $seqres.full
> +
> +echo "Silence is golden."
> +
> +_scratch_mkfs_xfs >> $seqres.full 2>&1

If this is a generic test, _scratch_mkfs should be used here.

> +_scratch_mount || _fail "mount failed"
> +
> +for i in $(seq 1 50); do
> + ($FSSTRESS_PROG -d $SCRATCH_MNT -n 999999 -p 4 >> $seqres.full &) \
> + > /dev/null 2>&1
> +
> + # purposely include 0 second sleeps to test shutdown immediately after
> + # recovery
> + sleep $((RANDOM % 3))
> + $XFS_IO_PROG -xc shutdown $SCRATCH_MNT
> +
> + ps -e | grep fsstress > /dev/null 2>&1
> + while [ $? == 0 ]; do

Better to use "-eq" for integers.

Thanks,
Eryu

> + $KILLALL_PROG -9 fsstress > /dev/null 2>&1
> + wait > /dev/null 2>&1
> + ps -e | grep fsstress > /dev/null 2>&1
> + done
> +
> + # quit if mount fails so we don't shutdown the host fs
> + _scratch_cycle_mount || _fail "cycle mount failed"
> +done
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/generic/999.out b/tests/generic/999.out
> new file mode 100644
> index 0000000..d254382
> --- /dev/null
> +++ b/tests/generic/999.out
> @@ -0,0 +1,2 @@
> +QA output created by 999
> +Silence is golden.
> diff --git a/tests/generic/group b/tests/generic/group
> index 4acae99..605a244 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -375,3 +375,4 @@
> 370 auto quick richacl
> 371 auto quick enospc prealloc
> 372 auto quick clone
> +999 auto log metadata
> --
> 2.5.5
>
> --
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