Re: [PATCH] xfs: stress test cycling parent pointers with online repair

Zorro Lang
2023-03-16T06:08:54Z

On Wed, Mar 15, 2023 at 02:17:30PM -0700, Darrick J. Wong wrote:
> On Thu, Mar 16, 2023 at 02:02:06AM +0800, Zorro Lang wrote:
> > On Tue, Mar 14, 2023 at 05:58:17PM -0700, Darrick J. Wong wrote:
> > > From: Darrick J. Wong <djwong@kernel.org>
> > >
> > > Add a couple of new tests to exercise directory and parent pointer
> > > repair against rename() calls moving child subdirectories from one
> > > parent to another. This is a useful test because it turns out that the
> > > VFS doesn't lock the child subdirectory (it does lock the parents), so
> > > repair must be more careful.
> > >
> > > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > > ---
> >
> > This patchset looks good to me.
> >
> > Two questions before acking this patch:
> > 1) The 2nd case fails [1] on mainline linux and xfsprogs, but test passed on
> > your djwong linux and xfsprogs repo. Is this expected? Is it a known issue
> > you've fixed in your repo?
>
> Yes. These two new 854/855 tests are a result of Jan Kara pointing out
> that if you do this:
>
> mkdir -p /tmp/a
> mv /tmp/a /mnt/
>
> The VFS won't lock /tmp/a while it does the rename. The upstream parent
> pointer checking code (which is really a dotdot checker) assumes that
> holding *only* i_rwsem is sufficient to prevent directory updates, which
> isn't true, and so the parent pointer checker emits false corruption
> reports.

Oh, that's it. Thanks for your explanation.

>
> All of that is fixed in djwong-dev.
>
> > 2) I remember there was a patchset [1] (from your team too) about parent pointer
> > test half years ago. I've reviewed its 3rd version, but no more response anymore.
> > Just curious, do you drop that patchset ? Or you hope to send it again after
> > xfsprogs and kernel support that feature? If dropped, I'll remove it from my
> > pending list :)
>
> It'll be back (soonish, I hope) once we finish nailing down the ondisk
> format and fixing up all the minor problems.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfstests-dev.git/log/?h=pptrs-ioctl-flexarray

Good to know that. No push, just ask the plan.

Now this patch is good to me, I'll merge it in next fstests release (this weekend).

Reviewed-by: Zorro Lang <zlang@redhat.com>

Thanks,
Zorro

>
> --D
>
> > Thanks,
> > Zorro
> >
> > [1]
> > xfs/855 33s ... _check_xfs_filesystem: filesystem on /dev/sda3 failed health check
> > (see /root/git/xfstests/results//simpledev/xfs/855.full for details)
> > - output mismatch (see /root/git/xfstests/results//simpledev/xfs/855.out.bad)
> > --- tests/xfs/855.out 2023-03-16 00:47:28.256187590 +0800
> > +++ /root/git/xfstests/results//simpledev/xfs/855.out.bad 2023-03-16 01:42:25.764902276 +0800
> > @@ -1,2 +1,37 @@
> > QA output created by 855
> > +xfs_scrub reports uncorrected errors:
> > +Corruption: inode 100663424 (12/128) parent pointer: Repairs are required. (scrub.c line 190)
> > +Corruption: inode 125829312 (15/192) parent pointer: Repairs are required. (scrub.c line 190)
> > +xfs_scrub reports uncorrected errors:
> > +Corruption: inode 117440647 (14/135) parent pointer: Repairs are required. (scrub.c line 190)
> > +xfs_scrub reports uncorrected errors:
> > ...
> > (Run 'diff -u /root/git/xfstests/tests/xfs/855.out /root/git/xfstests/results//simpledev/xfs/855.out.bad' to see the entire diff)
> > Ran: xfs/854 xfs/855
> > Failures: xfs/855
> > Failed 1 of 2 tests
> >
> > [2]
> > [PATCH v3 0/4] xfstests: add parent pointer tests
> > https://lore.kernel.org/fstests/20221028215605.17973-1-catherine.hoang@oracle.com/
> >
> >
> >
> > > common/fuzzy | 15 +++++++++++++++
> > > tests/xfs/854 | 38 ++++++++++++++++++++++++++++++++++++++
> > > tests/xfs/854.out | 2 ++
> > > tests/xfs/855 | 38 ++++++++++++++++++++++++++++++++++++++
> > > tests/xfs/855.out | 2 ++
> > > 5 files changed, 95 insertions(+)
> > > create mode 100755 tests/xfs/854
> > > create mode 100644 tests/xfs/854.out
> > > create mode 100755 tests/xfs/855
> > > create mode 100644 tests/xfs/855.out
> > >
> > > diff --git a/common/fuzzy b/common/fuzzy
> > > index 4609df4434..744d9ed65d 100644
> > > --- a/common/fuzzy
> > > +++ b/common/fuzzy
> > > @@ -995,6 +995,20 @@ __stress_scrub_fsstress_loop() {
> > > local focus=()
> > >
> > > case "$stress_tgt" in
> > > + "parent")
> > > + focus+=('-z')
> > > +
> > > + # Create a directory tree very gradually
> > > + for op in creat link mkdir; do
> > > + focus+=('-f' "${op}=2")
> > > + done
> > > + focus+=('-f' 'unlink=1' '-f' 'rmdir=1')
> > > +
> > > + # But do a lot of renames to cycle parent pointers
> > > + for op in rename rnoreplace rexchange; do
> > > + focus+=('-f' "${op}=40")
> > > + done
> > > + ;;
> > > "dir")
> > > focus+=('-z')
> > >
> > > @@ -1285,6 +1299,7 @@ __stress_scrub_check_commands() {
> > > # 'writeonly': Only perform fs updates, no reads.
> > > # 'symlink': Only create symbolic links.
> > > # 'mknod': Only create special files.
> > > +# 'parent': Focus on updating parent pointers
> > > #
> > > # The default is 'default' unless XFS_SCRUB_STRESS_TARGET is set.
> > > # -X Run this program to exercise the filesystem. Currently supported
> > > diff --git a/tests/xfs/854 b/tests/xfs/854
> > > new file mode 100755
> > > index 0000000000..0aa2c2ee4f
> > > --- /dev/null
> > > +++ b/tests/xfs/854
> > > @@ -0,0 +1,38 @@
> > > +#! /bin/bash
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +# Copyright (c) 2023 Oracle, Inc. All Rights Reserved.
> > > +#
> > > +# FS QA Test No. 854
> > > +#
> > > +# Race fsstress doing mostly renames and xfs_scrub in force-repair mode for a
> > > +# while to see if we crash or livelock.
> > > +#
> > > +. ./common/preamble
> > > +_begin_fstest online_repair dangerous_fsstress_repair
> > > +
> > > +_cleanup() {
> > > + cd /
> > > + _scratch_xfs_stress_scrub_cleanup &> /dev/null
> > > + rm -r -f $tmp.*
> > > +}
> > > +_register_cleanup "_cleanup" BUS
> > > +
> > > +# Import common functions.
> > > +. ./common/filter
> > > +. ./common/fuzzy
> > > +. ./common/inject
> > > +. ./common/xfs
> > > +
> > > +# real QA test starts here
> > > +_supported_fs xfs
> > > +_require_scratch
> > > +_require_xfs_stress_online_repair
> > > +
> > > +_scratch_mkfs > "$seqres.full" 2>&1
> > > +_scratch_mount
> > > +_scratch_xfs_stress_online_repair -S '-k' -x 'parent'
> > > +
> > > +# success, all done
> > > +echo Silence is golden
> > > +status=0
> > > +exit
> > > diff --git a/tests/xfs/854.out b/tests/xfs/854.out
> > > new file mode 100644
> > > index 0000000000..f8d9e27958
> > > --- /dev/null
> > > +++ b/tests/xfs/854.out
> > > @@ -0,0 +1,2 @@
> > > +QA output created by 854
> > > +Silence is golden
> > > diff --git a/tests/xfs/855 b/tests/xfs/855
> > > new file mode 100755
> > > index 0000000000..6daff05995
> > > --- /dev/null
> > > +++ b/tests/xfs/855
> > > @@ -0,0 +1,38 @@
> > > +#! /bin/bash
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +# Copyright (c) 2023 Oracle, Inc. All Rights Reserved.
> > > +#
> > > +# FS QA Test No. 855
> > > +#
> > > +# Race fsstress doing mostly renames and xfs_scrub in read-only mode for a
> > > +# while to see if we crash or livelock.
> > > +#
> > > +. ./common/preamble
> > > +_begin_fstest scrub dangerous_fsstress_scrub
> > > +
> > > +_cleanup() {
> > > + cd /
> > > + _scratch_xfs_stress_scrub_cleanup &> /dev/null
> > > + rm -r -f $tmp.*
> > > +}
> > > +_register_cleanup "_cleanup" BUS
> > > +
> > > +# Import common functions.
> > > +. ./common/filter
> > > +. ./common/fuzzy
> > > +. ./common/inject
> > > +. ./common/xfs
> > > +
> > > +# real QA test starts here
> > > +_supported_fs xfs
> > > +_require_scratch
> > > +_require_xfs_stress_scrub
> > > +
> > > +_scratch_mkfs > "$seqres.full" 2>&1
> > > +_scratch_mount
> > > +_scratch_xfs_stress_scrub -S '-n' -x 'parent'
> > > +
> > > +# success, all done
> > > +echo Silence is golden
> > > +status=0
> > > +exit
> > > diff --git a/tests/xfs/855.out b/tests/xfs/855.out
> > > new file mode 100644
> > > index 0000000000..fa60f65432
> > > --- /dev/null
> > > +++ b/tests/xfs/855.out
> > > @@ -0,0 +1,2 @@
> > > +QA output created by 855
> > > +Silence is golden
> > >
> >
>