#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2013 Oracle, Inc.  All Rights Reserved.
#
# 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.
#
. ./common/preamble
_begin_fstest shutdown auto log metadata

_cleanup()
{
	_cleanup_flakey
	cd /
	rm -f $tmp.*
}

# Import common functions.
. ./common/dmflakey

# Modify as appropriate.

_require_scratch
_require_dm_target flakey
_require_xfs_sysfs debug/log_recovery_delay

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.
_run_fsstress_bg -n 9999 -p 2 -w -d $SCRATCH_MNT
sleep 5
_scratch_shutdown -f
_kill_fsstress
_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
