common/dmlogwrites

##/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2015 Facebook, Inc.  All Rights Reserved.
#
# 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.
#
# Check if dax mount options are supported
# $1 can be either 'dax=always' or 'dax'
# dax=always
#      Check for the new dax options (dax=inode, dax=always or dax=never)
#      by passing "dax=always".
# dax
#      Check for the old dax or new dax=always by passing "dax".
# This only accepts 'dax=always' because dax=always, dax=inode and
# dax=never are always supported together.  So if the other options are
# required checking for 'dax=always' indicates support for the other 2.
_require_log_writes_dax_mountopt()
{
	[ -z "$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
	local mountopt=$1

	_log_writes_init $SCRATCH_DEV
	_log_writes_mkfs > /dev/null 2>&1
	_log_writes_mount "-o $mountopt" > /dev/null 2>&1
	# Check options to be sure.
	# XFS ignores dax option(or changes it to dax=never)
	# and goes on if dev underneath does not support dax.
	_fs_options $LOGWRITES_DMDEV | grep -Eq "dax(=always|,|$)"
	ret=$?
	_log_writes_cleanup
	if [ $ret -ne 0 ]; then
		_notrun "$LOGWRITES_DMDEV $FSTYP does not support -o $mountopt"
	fi
}

# Set up a dm-log-writes device
#
# blkdev: the specified target device
# length(optional): the mapped length in bytes
# Note that the entire size of the target device will be used
# if length is not specified.
_log_writes_init()
{
	local blkdev=$1
	local length=$2
	local BLK_DEV_SIZE

	[ -z "$blkdev" ] && _fail \
	"block dev must be specified for _log_writes_init"

	if [ -z "$length" ]; then
		BLK_DEV_SIZE=`blockdev --getsz $blkdev`
	else
		local blksz=`blockdev --getss $blkdev`
		BLK_DEV_SIZE=$((length / blksz))
	fi

	LOGWRITES_NAME=logwrites-test
	LOGWRITES_DMDEV=/dev/mapper/$LOGWRITES_NAME
	LOGWRITES_TABLE="0 $BLK_DEV_SIZE log-writes $blkdev $LOGWRITES_DEV"
	_dmsetup_create $LOGWRITES_NAME --table "$LOGWRITES_TABLE" || \
		_fail "failed to create log-writes device"
}

_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 blkdev upto the
# mark passed in.
_log_writes_replay_log()
{
	_mark=$1
	_blkdev=$2

	[ -z "$_blkdev" ] && _fail \
	"block dev must be specified for _log_writes_replay_log"

	$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 $_blkdev \
		--end-mark $_mark >> $seqres.full 2>&1
	[ $? -ne 0 ] && _fail "replay failed"
}

_log_writes_remove()
{
	_dmsetup_remove $LOGWRITES_NAME
}

_log_writes_cleanup()
{
	$UMOUNT_PROG $SCRATCH_MNT > /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
	local blkdev=$2

	[ -z "$end" ] && _fail \
	"end entry must be specified for _log_writes_replay_log_range"
	[ -z "$blkdev" ] && _fail \
	"block dev 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. We also dump all the
	# operations performed as this helps post-mortem analysis of failures.
	echo "=== replay to $end ===" >> $seqres.full
	$here/src/log-writes/replay-log -vv --log $LOGWRITES_DEV \
		--replay $blkdev --limit $(($end + 1)) \
		>> $seqres.full 2>&1
	[ $? -ne 0 ] && _fail "replay failed"
}