apfstests/common/scsi_debug

##/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2012 Red Hat, Inc. All Rights Reserved.
#
# Functions useful for tests on unique block devices

_require_scsi_debug()
{
	# make sure we have the module and it's not already used
	modinfo scsi_debug 2>&1 > /dev/null || _notrun "scsi_debug module not found"
	lsmod | grep -wq scsi_debug && (rmmod scsi_debug || _notrun "scsi_debug module in use")
	# make sure it has the features we need
	# logical/physical sectors plus unmap support all went in together
	modinfo scsi_debug | grep -wq sector_size || _notrun "scsi_debug too old"
}

# Args: [physical sector size, [logical sector size, [unaligned(0|1), [size in megs]]]]
_get_scsi_debug_dev()
{
	# Defaults to phys 512, logical 512, aligned
	physical=${1-512}
	logical=${2-512}
	unaligned=${3-0}
	size=${4-128}
	test -n "$4" && shift
	test -n "$3" && shift
	test -n "$2" && shift
	test -n "$1" && shift

	phys_exp=0
	while [ $logical -lt $physical ]; do
		let physical=physical/2
		let phys_exp=phys_exp+1
	done
	opts="sector_size=$logical physblk_exp=$phys_exp lowest_aligned=$unaligned dev_size_mb=$size $@"
	echo "scsi_debug options $opts" >> $seqres.full
	modprobe scsi_debug $opts
	[ $? -eq 0 ] || _fail "scsi_debug modprobe failed"
	sleep 1
	device=`grep -wl scsi_debug /sys/block/sd*/device/model | awk -F / '{print $4}'`
	echo "/dev/$device"
}

_put_scsi_debug_dev()
{
	lsmod | grep -wq scsi_debug || return

	n=2
	# use redirection not -q option of modprobe here, because -q of old
	# modprobe is only quiet when the module is not found, not when the
	# module is in use.
	while [ $n -ge 0 ] && ! modprobe -nr scsi_debug >/dev/null 2>&1; do
		sleep 1
		n=$((n-1))
	done
	rmmod scsi_debug || _fail "Could not remove scsi_debug module"
}