Add tests for support for segments smaller than the page size

Signed-off-by: Bart Van Assche <[email protected]>

common/rc

@@ -176,6 +176,14 @@ _have_kernel_config_file() {
 	return 0
 }
 
+_have_sub_page_limit_support() {
+	if [[ -e /sys/debug/block/sub_page_limit_queues ]]; then
+		return 0
+	fi
+	SKIP_REASONS+=("The block layer does not have sub-page limit support")
+	return 1
+}
+
 # Check if the specified kernel option is defined.
 _check_kernel_option() {
 	local f opt=$1

tests/block/099

@@ -0,0 +1,57 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2022 Google LLC
+#
+# Test support for segment sizes less than 4096 bytes.
+
+. tests/block/rc
+. common/null_blk
+
+DESCRIPTION="do IO on null-blk with 512 byte segments"
+TIMED=1
+
+requires() {
+	_have_fio
+	_have_null_blk
+	_have_sub_page_limit_support
+}
+
+test() {
+	local bs=4096
+
+	echo "Running ${TEST_NAME}"
+
+	if ! _init_null_blk nr_devices=0; then
+		echo "Loading null_blk failed"
+		return 1
+	fi
+	if ! grep -qw max_segment_size /sys/kernel/config/nullb/features; then
+		SKIP_REASONS+=("max_segment_size parameter is not supported")
+		return 1
+	fi
+	local nullb_params=(
+		blocksize="$bs"      # bytes
+		completion_nsec=0
+		max_segment_size=512 # bytes
+		memory_backed=1
+		size=1               # MiB
+		submit_queues=1
+		power=1
+	)
+	if ! _configure_null_blk nullb0 "${nullb_params[@]}"; then
+		echo "Configuring null_blk failed"
+		return 1
+	fi
+	fio --verify=md5 --rw=randwrite --bs=$bs --ioengine=psync --thread \
+		--group_reporting --sync=1 --direct=1 \
+		--name=block-099 --filename=/dev/nullb0 \
+		--output="${RESULTS_DIR}/block/fio-output-block-099.txt" \
+		>>"$FULL"
+	local fio_status=$?
+	rmdir /sys/kernel/config/nullb/nullb0
+	_exit_null_blk
+	case $fio_status in
+		0) echo "Passed";;
+		*) echo "Failed (fio status = $fio_status)";;
+	esac
+}

tests/block/099.out

@@ -0,0 +1,2 @@
+Running block/099
+Passed

tests/scsi/099

@@ -0,0 +1,55 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2022 Google LLC
+#
+# Test support for segment sizes less than 4096 bytes.
+
+. tests/block/rc
+. common/scsi_debug
+
+DESCRIPTION="do IO on scsi_debug with 512 byte segments"
+TIMED=1
+
+requires() {
+	_have_fio
+	_have_scsi_debug
+	_have_sub_page_limit_support
+}
+
+test() {
+	local bs=4096
+
+	echo "Running ${TEST_NAME}"
+	local scsi_debug_params=(
+		add_host=1
+		clustering=1
+		delay=0
+		sector_size="$bs"      # bytes
+	)
+	if _have_module_param scsi_debug max_segment_size; then
+		scsi_debug_params+=(max_segment_size=512) # bytes
+		echo "Segment size = 512" >>"$FULL"
+	fi
+	if ! _init_scsi_debug "${scsi_debug_params[@]}"; then
+		echo "Initializing scsi_debug failed"
+		return 1
+	fi
+	local blkdev=/dev/${SCSI_DEBUG_DEVICES[0]}
+	[ -b "$blkdev" ] || return 1
+	local ioengine
+	for ioengine in psync sg; do
+		echo "$ioengine"
+		fio --verify=md5 --rw=randwrite --bs=$bs --ioengine=$ioengine \
+		    --thread --group_reporting --sync=1 --direct=1 \
+		    --name=scsi-099 --filename="$blkdev" \
+		    --output="${RESULTS_DIR}/block/fio-output-scsi-099-$ioengine.txt" \
+		    >>"$FULL"
+		local fio_status=$?
+		[ $fio_status = 0 ] || break
+	done
+	_exit_scsi_debug
+	case $fio_status in
+		0) echo "Passed";;
+		*) echo "Failed (fio status = $fio_status)";;
+	esac
+}

tests/scsi/099.out

@@ -0,0 +1,4 @@
+Running scsi/099
+psync
+sg
+Passed