common/dmflakey

##/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2013 Fusion IO, Inc.  All Rights Reserved.
#
# common functions for setting up and tearing down a dmflakey device

FLAKEY_ALLOW_WRITES=0
FLAKEY_DROP_WRITES=1
FLAKEY_ERROR_WRITES=2

_init_flakey()
{
	local BLK_DEV_SIZE=`blockdev --getsz $SCRATCH_DEV`
	FLAKEY_DEV=/dev/mapper/flakey-test
	FLAKEY_TABLE="0 $BLK_DEV_SIZE flakey $SCRATCH_DEV 0 180 0"
	FLAKEY_TABLE_DROP="0 $BLK_DEV_SIZE flakey $SCRATCH_DEV 0 0 180 1 drop_writes"
	FLAKEY_TABLE_ERROR="0 $BLK_DEV_SIZE flakey $SCRATCH_DEV 0 0 180 1 error_writes"
	_dmsetup_create flakey-test --table "$FLAKEY_TABLE" || \
		_fatal "failed to create flakey device"
}

_mount_flakey()
{
	_scratch_options mount
	mount -t $FSTYP $SCRATCH_OPTIONS $MOUNT_OPTIONS $FLAKEY_DEV $SCRATCH_MNT
}

_unmount_flakey()
{
	$UMOUNT_PROG $SCRATCH_MNT
}

_cleanup_flakey()
{
	# If dmsetup load fails then we need to make sure to do resume here
	# otherwise the umount will hang
	$DMSETUP_PROG resume flakey-test > /dev/null 2>&1
	$UMOUNT_PROG $SCRATCH_MNT > /dev/null 2>&1
	_dmsetup_remove flakey-test
}

# _load_flakey_table <table> [lockfs]
#
# This defaults to --nolockfs, which doesn't freeze_fs() before loading the new
# table, so it simulates power failure.
_load_flakey_table()
{
	table="$FLAKEY_TABLE"
	[ $1 -eq $FLAKEY_DROP_WRITES ] && table="$FLAKEY_TABLE_DROP"
	[ $1 -eq $FLAKEY_ERROR_WRITES ] && table="$FLAKEY_TABLE_ERROR"

	suspend_opt="--nolockfs"
	[ $# -gt 1 ] && [ $2 -eq 1 ] && suspend_opt=""

	$DMSETUP_PROG suspend $suspend_opt flakey-test
	[ $? -ne 0 ] && _fatal "failed to suspend flakey-test"

	# There may be multiple dm targets in the table, and these dm targets
	# will be joined by the newline ("\n"). Option --table can not cope with
	# the multiple-targets case, so get them by reading from standard input.
	echo -e "$table" | $DMSETUP_PROG load flakey-test
	[ $? -ne 0 ] && _fatal "failed to load table into flakey-test"

	$DMSETUP_PROG resume flakey-test
	[ $? -ne 0 ] && _fatal  "failed to resume flakey-test"
}

# Silently drop all writes and unmount/remount to simulate a crash/power
# failure.
_flakey_drop_and_remount()
{
	_load_flakey_table $FLAKEY_DROP_WRITES
	_unmount_flakey

	if [ "x$1" = "xyes" ]; then
		_check_scratch_fs $FLAKEY_DEV
	fi

	_load_flakey_table $FLAKEY_ALLOW_WRITES
	_mount_flakey
}

_require_flakey_with_error_writes()
{
	local SIZE
	local TABLE
	local NAME=flakey-test

	_require_dm_target flakey

	SIZE=`blockdev --getsz $SCRATCH_DEV`
	TABLE="0 $SIZE flakey $SCRATCH_DEV 0 0 180 1 error_writes"

	_dmsetup_create $NAME --table "$TABLE" || \
		_notrun "This test requires error_writes feature in dm-flakey"

	_cleanup_flakey
}