apfstests/common/dmlogwrites

##/bin/bash
#
# Copyright (c) 2015 Facebook, 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
#
#
# common functions for setting up and tearing down a dm log-writes device

_require_log_writes()
{
	[ -z "$LOGWRITES_DEV" -o ! -b "$LOGWRITES_DEV" ] && \
		_notrun "This test requires a valid \$LOGWRITES_DEV"

	_exclude_scratch_mount_option dax
	_require_dm_target log-writes
	_require_test_program "log-writes/replay-log"
}

# Starting from v4.15-rc1, DAX support was added to dm-log-writes, but note
# that it doesn't track the data that we write via the mmap(), so we can't do
# any data integrity checking. We can only verify that the metadata writes for
# the page faults happened, e.g. when mmap(2) with MAP_SYNC flag.
#
# Introduce a new helper to check if dm-log-writes target supports DAX
# explicitly. But this is considered as a temporary workaround, we want to move
# all the DAX check back to _require_log_writes when dm-log-writes gains full
# DAX support and remove this helper.
_require_log_writes_dax()
{
	[ -z "$LOGWRITES_DEV" -o ! -b "$LOGWRITES_DEV" ] && \
		_notrun "This test requires a valid \$LOGWRITES_DEV"

	_require_dm_target log-writes
	_require_test_program "log-writes/replay-log"

	local ret=0
	_log_writes_init
	_log_writes_mkfs > /dev/null 2>&1
	_log_writes_mount -o dax > /dev/null 2>&1
	# Check options to be sure. XFS ignores dax option
	# and goes on if dev underneath does not support dax.
	_fs_options $LOGWRITES_DMDEV | grep -qw "dax"
	ret=$?
	_log_writes_cleanup
	if [ $ret -ne 0 ]; then
		_notrun "$LOGWRITES_DMDEV $FSTYP does not support -o dax"
	fi
}

_log_writes_init()
{
	local BLK_DEV_SIZE=`blockdev --getsz $SCRATCH_DEV`
	LOGWRITES_NAME=logwrites-test
	LOGWRITES_DMDEV=/dev/mapper/$LOGWRITES_NAME
	LOGWRITES_TABLE="0 $BLK_DEV_SIZE log-writes $SCRATCH_DEV $LOGWRITES_DEV"
	$DMSETUP_PROG create $LOGWRITES_NAME --table "$LOGWRITES_TABLE" || \
		_fail "failed to create log-writes device"
	$DMSETUP_PROG mknodes > /dev/null 2>&1
}

_log_writes_mark()
{
	[ $# -ne 1 ] && _fail "_log_writes_mark takes one argument"
	$DMSETUP_PROG message $LOGWRITES_NAME 0 mark $1
}

_log_writes_mkfs()
{
	_scratch_options mkfs
	_mkfs_dev $SCRATCH_OPTIONS $LOGWRITES_DMDEV
	_log_writes_mark mkfs
}

_log_writes_mount()
{
	_scratch_options mount
	$MOUNT_PROG -t $FSTYP `_common_dev_mount_options $*` $SCRATCH_OPTIONS \
		$LOGWRITES_DMDEV $SCRATCH_MNT
}

_log_writes_unmount()
{
	$UMOUNT_PROG $SCRATCH_MNT
}

# _log_writes_replay_log <mark>
#
# This replays the log contained on $LOGWRITES_DEV onto $SCRATCH_DEV upto the
# mark passed in.
_log_writes_replay_log()
{
	_mark=$1

	$here/src/log-writes/replay-log --log $LOGWRITES_DEV --find \
		--end-mark $_mark >> $seqres.full 2>&1
	[ $? -ne 0 ] && _fail "mark '$_mark' does not exist"

	$here/src/log-writes/replay-log --log $LOGWRITES_DEV --replay $SCRATCH_DEV \
		--end-mark $_mark >> $seqres.full 2>&1
	[ $? -ne 0 ] && _fail "replay failed"
}

_log_writes_remove()
{
	$DMSETUP_PROG remove $LOGWRITES_NAME > /dev/null 2>&1
	$DMSETUP_PROG mknodes > /dev/null 2>&1
}

_log_writes_cleanup()
{
	$UMOUNT_PROG $SCRATCH_MNT > /dev/null 2>&1
	# wait for device to be fully settled so that 'dmsetup remove' doesn't
	# fail due to EBUSY
	$UDEV_SETTLE_PROG >/dev/null 2>&1
	_log_writes_remove
}

# Convert log writes mark to entry number
# Result entry number is output to stdout, could be empty if not found
_log_writes_mark_to_entry_number()
{
	local mark=$1
	local ret

	[ -z "$mark" ] && _fatal \
		"mark must be given for _log_writes_mark_to_entry_number"

	ret=$($here/src/log-writes/replay-log --find --log $LOGWRITES_DEV \
		--end-mark $mark 2> /dev/null)
	[ -z "$ret" ] && return
	ret=$(echo "$ret" | cut -f1 -d\@)
	echo "mark $mark has entry number $ret" >> $seqres.full
	echo "$ret"
}

# Find next fua write entry number
# Result entry number is output to stdout, could be empty if not found
_log_writes_find_next_fua()
{
	local start_entry=$1
	local ret

	[ -z "$start_entry" ] && start_entry=0
	ret=$($here/src/log-writes/replay-log --find --log $LOGWRITES_DEV \
	      --next-fua --start-entry $start_entry 2> /dev/null)
	[ -z "$ret" ] && return

	# Result should be something like "1024@offset" where 1024 is the
	# entry number we need
	ret=$(echo "$ret" | cut -f1 -d\@)
	echo "next fua is entry number $ret" >> $seqres.full
	echo "$ret"
}

# Replay log range to specified entry
# $1:	End entry. The entry with this number *WILL* be replayed
_log_writes_replay_log_range()
{
	local end=$1

	[ -z "$end" ] && _fail \
	"end entry must be specified for _log_writes_replay_log_range"

	# To ensure we replay the last entry,
	# we need to manually increase the end entry number to ensure
	# it's played
	echo "=== replay to $end ===" >> $seqres.full
	$here/src/log-writes/replay-log --log $LOGWRITES_DEV \
		--replay $SCRATCH_DEV --limit $(($end + 1)) \
		>> $seqres.full 2>&1
	[ $? -ne 0 ] && _fail "replay failed"
}