From: Frank Sorenson <frank@tuxrocks.com>
To: Dave Chinner <david@fromorbit.com>,
"Darrick J. Wong" <djwong@kernel.org>
Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 2/2] xfs: use iomap_valid method to detect stale cached iomaps
Date: Tue, 4 Oct 2022 18:34:03 -0500 [thread overview]
Message-ID: <d00aff43-2bdc-0724-1996-4e58e061ecfd@redhat.com> (raw)
In-Reply-To: <20220929014534.GE3600936@dread.disaster.area>
On 9/28/22 20:45, Dave Chinner wrote:
> On Tue, Sep 27, 2022 at 09:54:27PM -0700, Darrick J. Wong wrote:
>> Btw, can you share the reproducer?
> Not sure. The current reproducer I have is 2500 lines of complex C
> code that was originally based on a reproducer the original reporter
> provided. It does lots of stuff that isn't directly related to
> reproducing the issue, and will be impossible to review and maintain
> as it stands in fstests.
Too true. Fortunately, now that I understand the necessary conditions
and IO patterns, I managed to prune it all down to ~75 lines of bash
calling xfs_io. See below.
Frank
--
Frank Sorenson
sorenson@redhat.com
Principal Software Maintenance Engineer
Global Support Services - filesystems
Red Hat
###########################################
#!/bin/bash
# Frank Sorenson <sorenson@redhat.com>, 2022
num_files=8
num_writers=3
KiB=1024
MiB=$(( $KiB * $KiB ))
GiB=$(( $KiB * $KiB * $KiB ))
file_size=$(( 500 * $MiB ))
#file_size=$(( 1 * $GiB ))
write_size=$(( 1 * $MiB ))
start_offset=512
num_loops=$(( ($file_size - $start_offset + (($num_writers * $write_size) - 1)) / ($num_writers * $write_size) ))
total_size=$(( ($num_loops * $num_writers * $write_size) + $start_offset ))
cgroup_path=/sys/fs/cgroup/test_write_bug
mkdir -p $cgroup_path || { echo "unable to create cgroup" ; exit ; }
max_mem=$(( 40 * $MiB ))
high_mem=$(( ($max_mem * 9) / 10 ))
echo $high_mem >$cgroup_path/memory.high
echo $max_mem >$cgroup_path/memory.max
mkdir -p testfiles
rm -f testfiles/expected
xfs_io -f -c "pwrite -b $((1 * $MiB)) -S 0x40 0 $total_size" testfiles/expected >/dev/null 2>&1
expected_sum=$(md5sum testfiles/expected | awk '{print $1}')
echo $$ > $cgroup_path/cgroup.procs || exit # put ourselves in the cgroup
do_one_testfile() {
filenum=$1
cpids=""
offset=$start_offset
rm -f testfiles/test$filenum
xfs_io -f -c "pwrite -b $start_offset -S 0x40 0 $start_offset" testfiles/test$filenum >/dev/null 2>&1
while [[ $offset -lt $file_size ]] ; do
cpids=""
for i in $(seq 1 $num_writers) ; do
xfs_io -f -c "pwrite -b $write_size -S 0x40 $(( ($offset + (($num_writers - $i) * $write_size) ) )) $write_size" testfiles/test$filenum >/dev/null 2>&1 &
cpids="$cpids $!"
done
wait $cpids
offset=$(( $offset + ($num_writers * $write_size) ))
done
}
round=1
while [[ 42 ]] ; do
echo "test round: $round"
cpids=""
for i in $(seq 1 $num_files) ; do
do_one_testfile $i &
cpids="$cpids $!"
done
wait $cpids
replicated="" # now check the files
for i in $(seq 1 $num_files) ; do
sum=$(md5sum testfiles/test$i | awk '{print $1}')
[[ $sum == $expected_sum ]] || replicated="$replicated testfiles/test$i"
done
[[ -n $replicated ]] && break
round=$(($round + 1))
done
echo "replicated bug with: $replicated"
echo $$ > /sys/fs/cgroup/cgroup.procs
rmdir $cgroup_path
next prev parent reply other threads:[~2022-10-04 23:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-21 8:29 [RFC PATCH 0/2] iomap/xfs: fix data corruption due to stale cached iomaps Dave Chinner
2022-09-21 8:29 ` [PATCH 1/2] iomap: write iomap validity checks Dave Chinner
2022-09-22 3:40 ` Darrick J. Wong
2022-09-22 23:16 ` Dave Chinner
2022-09-28 4:48 ` Darrick J. Wong
2022-09-21 8:29 ` [PATCH 2/2] xfs: use iomap_valid method to detect stale cached iomaps Dave Chinner
2022-09-22 3:44 ` Darrick J. Wong
2022-09-23 0:04 ` Dave Chinner
2022-09-28 4:54 ` Darrick J. Wong
2022-09-29 1:45 ` Dave Chinner
2022-10-04 23:34 ` Frank Sorenson [this message]
2022-10-05 1:34 ` Darrick J. Wong
2022-09-22 4:25 ` [RFC PATCH 0/2] iomap/xfs: fix data corruption due to " Darrick J. Wong
2022-09-22 22:59 ` Dave Chinner
2022-09-28 5:16 ` Darrick J. Wong
2022-09-29 2:11 ` Dave Chinner
2022-09-29 2:15 ` Darrick J. Wong
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