selftests: ublk: move zero copy feature check into _add_ublk_dev()

Move zero copy feature check into _add_ublk_dev() since we will have
more tests which requires to cover zero copy.

Then one check function of _check_add_dev() has to be added for dealing
with cleanup since '_add_ublk_dev()' is run in sub-shell, and we can't
exit from it to terminal shell.

Meantime always return error code from _add_ublk_dev().

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250303124324.3563605-8-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

tools/testing/selftests/ublk/test_common.sh

@@ -1,6 +1,8 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+UBLK_SKIP_CODE=4
+
 _create_backfile() {
 	local my_size=$1
 	local my_file
@@ -79,12 +81,37 @@ _prep_test() {
 	echo "ublk $type: $*"
 }
 
+_remove_test_files()
+{
+	local files=$*
+
+	for file in ${files}; do
+		[ -f "${file}" ] && rm -f "${file}"
+	done
+}
+
 _show_result()
 {
-	if [ "$2" -ne 0 ]; then
-		echo "$1 : [FAIL]"
-	else
+	if [ "$2" -eq 0 ]; then
 		echo "$1 : [PASS]"
+	elif [ "$2" -eq 4 ]; then
+		echo "$1 : [SKIP]"
+	else
+		echo "$1 : [FAIL]"
+	fi
+	[ "$2" -ne 0 ] && exit "$2"
+	return 0
+}
+
+# don't call from sub-shell, otherwise can't exit
+_check_add_dev()
+{
+	local tid=$1
+	local code=$2
+	shift 2
+	if [ "${code}" -ne 0 ]; then
+		_remove_test_files "$@"
+		_show_result "${tid}" "${code}"
 	fi
 }
 
@@ -92,13 +119,28 @@ _cleanup_test() {
 	"${UBLK_PROG}" del -a
 }
 
+_have_feature()
+{
+	if  $UBLK_PROG "features" | grep "$1" > /dev/null 2>&1; then
+		return 0
+	fi
+	return 1
+}
+
 _add_ublk_dev() {
 	local kublk_temp;
 	local dev_id;
 
+	if echo "$@" | grep -q "\-z"; then
+		if ! _have_feature "ZERO_COPY"; then
+			return ${UBLK_SKIP_CODE}
+		fi
+	fi
+
 	kublk_temp=$(mktemp /tmp/kublk-XXXXXX)
 	if ! "${UBLK_PROG}" add "$@" > "${kublk_temp}" 2>&1; then
 		echo "fail to add ublk dev $*"
+		rm -f "${kublk_temp}"
 		return 255
 	fi
 
@@ -108,13 +150,5 @@ _add_ublk_dev() {
 	echo "${dev_id}"
 }
 
-_have_feature()
-{
-	if  "$UBLK_PROG" "features" | grep "$1" > /dev/null 2>&1; then
-		return 0
-	fi
-	return 1
-}
-
 UBLK_PROG=$(pwd)/kublk
 export UBLK_PROG

tools/testing/selftests/ublk/test_loop_01.sh

@@ -11,6 +11,7 @@ _prep_test "loop" "write and verify test"
 backfile_0=$(_create_backfile 256M)
 
 dev_id=$(_add_ublk_dev -t loop "$backfile_0")
+_check_add_dev $TID $? "${backfile_0}"
 
 # run fio over the ublk disk
 fio --name=write_and_verify \

tools/testing/selftests/ublk/test_loop_02.sh

@@ -9,8 +9,8 @@ ERR_CODE=0
 _prep_test "loop" "mkfs & mount & umount"
 
 backfile_0=$(_create_backfile 256M)
-
 dev_id=$(_add_ublk_dev -t loop "$backfile_0")
+_check_add_dev $TID $? "$backfile_0"
 
 _mkfs_mount_test /dev/ublkb"${dev_id}"
 ERR_CODE=$?

tools/testing/selftests/ublk/test_loop_03.sh

@@ -6,13 +6,11 @@
 TID="loop_03"
 ERR_CODE=0
 
-_have_feature "ZERO_COPY" || exit 4
-
 _prep_test "loop" "write and verify over zero copy"
 
 backfile_0=$(_create_backfile 256M)
-
 dev_id=$(_add_ublk_dev -t loop -z "$backfile_0")
+_check_add_dev $TID $? "$backfile_0"
 
 # run fio over the ublk disk
 fio --name=write_and_verify \

tools/testing/selftests/ublk/test_loop_04.sh

@@ -9,8 +9,8 @@ ERR_CODE=0
 _prep_test "loop" "mkfs & mount & umount with zero copy"
 
 backfile_0=$(_create_backfile 256M)
-
 dev_id=$(_add_ublk_dev -t loop -z "$backfile_0")
+_check_add_dev $TID $? "$backfile_0"
 
 _mkfs_mount_test /dev/ublkb"${dev_id}"
 ERR_CODE=$?

tools/testing/selftests/ublk/test_null_01.sh

@@ -9,6 +9,7 @@ ERR_CODE=0
 _prep_test "null" "basic IO test"
 
 dev_id=$(_add_ublk_dev -t null)
+_check_add_dev $TID $?
 
 # run fio over the two disks
 fio --name=job1 --filename=/dev/ublkb"${dev_id}" --ioengine=libaio --rw=readwrite --iodepth=32 --size=256M > /dev/null 2>&1