tests/xfs/051

#! /bin/bash
# FS QA Test No. 051
#
# Simulate a buffer use after free race in XFS log recovery. The race triggers
# on I/O failures during log recovery. Note that this test is dangerous as it
# causes BUG() errors or a panic.
#
#-----------------------------------------------------------------------
# Copyright (c) 2013 Oracle, 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_PROG > /dev/null 2>&1
	_scratch_unmount > /dev/null 2>&1
}

# get standard environment, filters and checks
. ./common/rc
. ./common/dmflakey

# Modify as appropriate.
_supported_fs xfs
_supported_os Linux

_require_scratch
_require_dm_target flakey
_require_xfs_sysfs debug/log_recovery_delay
_require_command "$KILLALL_PROG" killall

echo "Silence is golden."

_scratch_mkfs_xfs >/dev/null 2>&1
_scratch_mount

# Start a workload and shutdown the fs. The subsequent mount will require log
# recovery.
$FSSTRESS_PROG -n 9999 -p 2 -w -d $SCRATCH_MNT > /dev/null 2>&1 &
sleep 5
src/godown -f $SCRATCH_MNT
$KILLALL_PROG -q $FSSTRESS_PROG
wait
_scratch_unmount

# Initialize a dm-flakey device that will pass I/Os for 5s and fail thereafter.
_init_flakey
BLK_DEV_SIZE=`blockdev --getsz $SCRATCH_DEV`
FLAKEY_TABLE="0 $BLK_DEV_SIZE flakey $SCRATCH_DEV 0 5 180"
_load_flakey_table $FLAKEY_ALLOW_WRITES

# Set a 10s log recovery delay and mount the flakey device. This should allow
# initial writes to proceed (e.g., stale log block reset) and then let the
# flakey uptime timer expire such that I/Os will fail by the time log recovery
# starts.
echo 10 > /sys/fs/xfs/debug/log_recovery_delay

# The mount should fail due to dm-flakey. Note that this is dangerous on kernels
# without the xfs_buf log recovery race fixes.
_mount_flakey > /dev/null 2>&1

echo 0 > /sys/fs/xfs/debug/log_recovery_delay

_cleanup_flakey

# replay the log
_scratch_mount
_scratch_unmount

# success, all done
status=0
exit