Re: [PATCH v3 2/4] generic: test hardlink to unlinked file

[Brian Foster <bfoster@redhat.com>]

On Fri, Apr 03, 2015 at 03:17:20PM +0800, Eryu Guan wrote:
> Kernel commit
> 
> aae8a97 fs: Don't allow to create hardlink for deleted file
> 
> disabled hardlink to unlinked file.
> 
> Test the race between link and unlink, which could end up adding link
> count to an unlinked file and leading to fs corruption on xfs.
> 
> Test case was originally written by Eric Sandeen.
> 
> Signed-off-by: Eryu Guan <eguan@redhat.com>
> ---

Looks good and runs fine for me now:

Reviewed-by: Brian Foster <bfoster@redhat.com>

> v3:
> - rebase and re-numbered to generic/084
> - sleep 1 before removing all files being tailed
> 
> v2:
> - create different link file in each iteration in link_unlink_storm(), which
>   is confirmed to be able to reproduce the original corruption
> - remove all newly created & tail'ed files at last, out of the loop, to avoid
>   tail & rm race
> - iterate $nr_cpu times to do the link_unlink_storm, not a fixed number
> - add to quick group
> 
>  tests/generic/084     | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/084.out |   2 +
>  tests/generic/group   |   1 +
>  3 files changed, 107 insertions(+)
>  create mode 100755 tests/generic/084
>  create mode 100644 tests/generic/084.out
> 
> diff --git a/tests/generic/084 b/tests/generic/084
> new file mode 100755
> index 0000000..3fec6c2
> --- /dev/null
> +++ b/tests/generic/084
> @@ -0,0 +1,104 @@
> +#! /bin/bash
> +# FS QA Test No. 084
> +#
> +# Test hardlink to unlinked file.
> +#
> +# Regression test for commit:
> +# aae8a97 fs: Don't allow to create hardlink for deleted file
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2015 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.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +_require_scratch
> +
> +link_unlink_storm()
> +{
> +	local src=$1
> +	local target=$2
> +	local i=0
> +
> +	while true; do
> +		ln -f $src $target.$i >/dev/null 2>&1
> +		rm -f $target.$i >/dev/null 2>&1
> +		let i=i+1
> +	done
> +}
> +
> +rm -f $seqres.full
> +nr_cpu=`$here/src/feature -o`
> +echo "Silence is golden"
> +
> +_scratch_mkfs >>$seqres.full 2>&1
> +_scratch_mount
> +
> +# create, open & unlinked files so unlinked inode list is not empty
> +for i in `seq 1 $nr_cpu`; do
> +	testfile=$SCRATCH_MNT/$seq.unlinked.$i
> +	touch $testfile
> +	tail -f $testfile &
> +	tail_pids="$tail_pids $!"
> +done
> +# give tail some time to open the file before the file is removed
> +sleep 1
> +rm -f $SCRATCH_MNT/$seq.unlinked.*
> +
> +# start link/unlink storm
> +src=$SCRATCH_MNT/$seq.target
> +touch $src
> +for i in `seq 1 $nr_cpu`; do
> +	target=$SCRATCH_MNT/$seq.target.link.$i
> +	link_unlink_storm $src $target &
> +	link_pids="$link_pids $!"
> +done
> +
> +# remove & re-create target to race with link/unlink
> +while true; do
> +	rm -f $src
> +	touch $src
> +done &
> +sleep 5
> +kill $! >/dev/null 2>&1
> +
> +kill $tail_pids $link_pids >/dev/null 2>&1
> +wait $tail_pids $link_pids
> +
> +# all done, no oops/hang expected, _check_filesystems checks SCRATCH_DEV after test
> +status=0
> +exit
> diff --git a/tests/generic/084.out b/tests/generic/084.out
> new file mode 100644
> index 0000000..022f013
> --- /dev/null
> +++ b/tests/generic/084.out
> @@ -0,0 +1,2 @@
> +QA output created by 084
> +Silence is golden
> diff --git a/tests/generic/group b/tests/generic/group
> index 4fe2189..5cbc1fe 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -86,6 +86,7 @@
>  081 auto quick
>  082 auto quick
>  083 rw auto enospc stress
> +084 auto metadata quick
>  088 perms auto quick
>  089 metadata auto
>  091 rw auto quick
> -- 
> 1.8.3.1
> 
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