From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from aserp1040.oracle.com ([141.146.126.69]:46577 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964845AbdIZXln (ORCPT ); Tue, 26 Sep 2017 19:41:43 -0400 Date: Tue, 26 Sep 2017 16:37:52 -0700 From: Liu Bo Subject: Re: [PATCH v2] fstests: btrfs/150 regression test for reading compressed data Message-ID: <20170926233752.GB27095@lim.localdomain> Reply-To: bo.li.liu@oracle.com References: <20170920235243.11822-1-bo.li.liu@oracle.com> <20170922232127.12032-1-bo.li.liu@oracle.com> <20170926090236.GI8034@eguan.usersys.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170926090236.GI8034@eguan.usersys.redhat.com> Sender: fstests-owner@vger.kernel.org To: Eryu Guan Cc: fstests@vger.kernel.org, linux-btrfs@vger.kernel.org List-ID: On Tue, Sep 26, 2017 at 05:02:36PM +0800, Eryu Guan wrote: > On Fri, Sep 22, 2017 at 05:21:27PM -0600, Liu Bo wrote: > > We had a bug in btrfs compression code which could end up with a > > kernel panic. > > > > This is adding a regression test for the bug and I've also sent a > > kernel patch to fix the bug. > > > > The patch is "Btrfs: fix kernel oops while reading compressed data". > > > > Signed-off-by: Liu Bo > > Hmm, I can't reproduce the panic with 4.13 kernel, which doesn't have > the fix applied. Can you please help confirm if it panics on your test > environment? > Yes, it is reproducible on my box, hrm...I'll be running it more times to double check. > > --- > > v2: - Fix ambiguous copyright. > > - Use /proc/$pid/make-it-fail to specify IO failure > > - Use bash -c to run test only when pid is odd. > > - Add test to dangerous group. > > > > tests/btrfs/150 | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > > tests/btrfs/150.out | 3 ++ > > tests/btrfs/group | 1 + > > 3 files changed, 107 insertions(+) > > create mode 100755 tests/btrfs/150 > > create mode 100644 tests/btrfs/150.out > > > > diff --git a/tests/btrfs/150 b/tests/btrfs/150 > > new file mode 100755 > > index 0000000..8891c38 > > --- /dev/null > > +++ b/tests/btrfs/150 > > @@ -0,0 +1,103 @@ > > +#! /bin/bash > > +# FS QA Test btrfs/150 > > +# > > +# This is a regression test which ends up with a kernel oops in btrfs. > > +# It occurs when btrfs's read repair happens while reading a compressed > > +# extent. > > +# The patch to fix it is > > +# Btrfs: fix kernel oops while reading compressed data > > +# > > +#----------------------------------------------------------------------- > > +# Copyright (c) 2017 Oracle. 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 > > + > > +# remove previous $seqres.full before test > > +rm -f $seqres.full > > + > > +# real QA test starts here > > + > > +# Modify as appropriate. > > +_supported_fs btrfs > > +_supported_os Linux > > +_require_scratch > > +_require_fail_make_request > > +_require_scratch_dev_pool 2 > > Trailing whitespace in above line. > > > + > > +SYSFS_BDEV=`_sysfs_dev $SCRATCH_DEV` > > +enable_io_failure() > > +{ > > + echo 100 > $DEBUGFS_MNT/fail_make_request/probability > > + echo 1000 > $DEBUGFS_MNT/fail_make_request/times > > + echo 0 > $DEBUGFS_MNT/fail_make_request/verbose > > + echo 1 > $SYSFS_BDEV/make-it-fail > > +} > > + > > +disable_io_failure() > > +{ > > + echo 0 > $SYSFS_BDEV/make-it-fail > > + echo 0 > $DEBUGFS_MNT/fail_make_request/probability > > + echo 0 > $DEBUGFS_MNT/fail_make_request/times > > +} > > + > > +_scratch_pool_mkfs "-d raid1 -b 1G" >> $seqres.full 2>&1 > > + > > +# It doesn't matter which compression algorithm we use. > > +_scratch_mount -ocompress > > + > > +# Create a file with all data being compressed > > +$XFS_IO_PROG -f -c "pwrite -W 0 8K" $SCRATCH_MNT/foobar | _filter_xfs_io > > + > > +# Raid1 consists of two copies and btrfs decides which copy to read by reader's > > +# %pid. Now we inject errors to copy #1 and copy #0 is good. We want to read > > +# the bad copy to trigger read-repair. > > +while [[ -z $result ]]; do > > + # invalidate the page cache > > + $XFS_IO_PROG -f -c "fadvise -d 0 8K" $SCRATCH_MNT/foobar > > Does 'echo 3 > /proc/sys/vm/drop_caches' work? > Yes, it works, drop_caches is system-wide, while here I'm just dropping caches on this single inode. Or are you implying that it's 'fadvise' that makes the test fail to show oops? thanks, -liubo > Thanks, > Eryu > > > + > > + enable_io_failure > > + > > + result=$(bash -c " > > + if [ \$((\$\$ % 2)) == 1 ]; then > > + echo 1 > /proc/\$\$/make-it-fail > > + exec $XFS_IO_PROG -c \"pread 0 8K\" \$SCRATCH_MNT/foobar > > + fi") > > + > > + disable_io_failure > > +done > > + > > +# success, all done > > +status=0 > > +exit > > diff --git a/tests/btrfs/150.out b/tests/btrfs/150.out > > new file mode 100644 > > index 0000000..c492c24 > > --- /dev/null > > +++ b/tests/btrfs/150.out > > @@ -0,0 +1,3 @@ > > +QA output created by 150 > > +wrote 8192/8192 bytes at offset 0 > > +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) > > diff --git a/tests/btrfs/group b/tests/btrfs/group > > index 70c3f05..e73bb1b 100644 > > --- a/tests/btrfs/group > > +++ b/tests/btrfs/group > > @@ -152,3 +152,4 @@ > > 147 auto quick send > > 148 auto quick rw > > 149 auto quick send compress > > +150 auto quick dangerous > > -- > > 2.5.0 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe fstests" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html