selftests: ublk: add one stress test for covering IO vs. removing device

Add stress_test_01 for running IO vs. removing device for verifying that
ublk device removal can work as expected when heavy IO workloads are in
progress.

null, loop and loop/zc are covered in this tests.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250303124324.3563605-10-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Ming Lei

tools/testing/selftests/ublk/Makefile

@@ -9,6 +9,8 @@ TEST_PROGS += test_loop_02.sh
 TEST_PROGS += test_loop_03.sh
 TEST_PROGS += test_loop_04.sh
 
+TEST_PROGS += test_stress_01.sh
+
 TEST_GEN_PROGS_EXTENDED = kublk
 
 include ../lib.mk

tools/testing/selftests/ublk/test_common.sh

@@ -155,5 +155,31 @@ _add_ublk_dev() {
 	echo "${dev_id}"
 }
 
+__remove_ublk_dev_return() {
+	local dev_id=$1
+
+	${UBLK_PROG} del -n "${dev_id}"
+	local res=$?
+	udevadm settle
+	return ${res}
+}
+
+__run_io_and_remove()
+{
+	local dev_id=$1
+	local size=$2
+
+	fio --name=job1 --filename=/dev/ublkb"${dev_id}" --ioengine=libaio \
+		--rw=readwrite --iodepth=64 --size="${size}" --numjobs=4 \
+		--runtime=20 --time_based > /dev/null 2>&1 &
+	sleep 2
+	if ! __remove_ublk_dev_return "${dev_id}"; then
+		echo "delete dev ${dev_id} failed"
+		return 255
+	fi
+	wait
+}
+
+
 UBLK_PROG=$(pwd)/kublk
 export UBLK_PROG

tools/testing/selftests/ublk/test_stress_01.sh

@@ -0,0 +1,47 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+. test_common.sh
+TID="stress_01"
+ERR_CODE=0
+DEV_ID=-1
+
+ublk_io_and_remove()
+{
+	local size=$1
+	shift 1
+	local backfile=""
+	if echo "$@" | grep -q "loop"; then
+		backfile=${*: -1}
+	fi
+	DEV_ID=$(_add_ublk_dev "$@")
+	_check_add_dev $TID $? "${backfile}"
+
+	echo "run ublk IO vs. remove device(ublk add $*)"
+	if ! __run_io_and_remove "${DEV_ID}" "${size}"; then
+		echo "/dev/ublkc${DEV_ID} isn't removed"
+		_remove_backfile "${backfile}"
+		exit 255
+	fi
+}
+
+_prep_test "stress" "run IO and remove device"
+
+ublk_io_and_remove 8G -t null
+ERR_CODE=$?
+if [ ${ERR_CODE} -ne 0 ]; then
+	_show_result $TID $ERR_CODE
+fi
+
+BACK_FILE=$(_create_backfile 256M)
+ublk_io_and_remove 256M -t loop "${BACK_FILE}"
+ERR_CODE=$?
+if [ ${ERR_CODE} -ne 0 ]; then
+	_show_result $TID $ERR_CODE
+fi
+
+ublk_io_and_remove 256M -t loop -z "${BACK_FILE}"
+ERR_CODE=$?
+_cleanup_test "stress"
+_remove_backfile "${BACK_FILE}"
+_show_result $TID $ERR_CODE