Re: [PATCH v3 blktests 1/2] scsi/009: add atomic write tests

[John Garry <john.g.garry@oracle.com>]

On 05/02/2025 23:10, Alan Adamson wrote:
> Tests basic atomic write functionality. If no scsi test device is provided,
> a scsi_debug device will be used. Testing areas include:
> 
> - Verify sysfs atomic write attributes are consistent with
>    atomic write attributes advertised by scsi_debug.
> - Verify the atomic write paramters of statx are correct using
>    xfs_io.
> - Perform a pwritev2() (with and without RWF_ATOMIC flag) using
>    xfs_io:
>      - maximum byte size (atomic_write_unit_max_bytes)
>      - minimum byte size (atomic_write_unit_min_bytes)
>      - a write larger than atomic_write_unit_max_bytes
>      - a write smaller than atomic_write_unit_min_bytes
> 
> Signed-off-by: Alan Adamson <alan.adamson@oracle.com>

generally looks ok, thanks, but a couple of comments

> ---
>   common/rc          |   8 ++
>   common/xfs         |  58 ++++++++++++

I suppose that this common stuff could go in a separate prep patch, but 
it doesn't bother me too much

>   tests/scsi/009     | 229 +++++++++++++++++++++++++++++++++++++++++++++
>   tests/scsi/009.out |  18 ++++
>   4 files changed, 313 insertions(+)
>   create mode 100755 tests/scsi/009
>   create mode 100644 tests/scsi/009.out
> 
> diff --git a/common/rc b/common/rc
> index bcb215d35114..06c0a416e3e1 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -292,6 +292,14 @@ _require_test_dev_can_discard() {
>   	return 0
>   }
>   
> +_require_device_support_atomic_writes() {
> +	_require_test_dev_sysfs queue/atomic_write_max_bytes
> +	if (( $(< "${TEST_DEV_SYSFS}"/queue/atomic_write_max_bytes) == 0 )); then
> +		SKIP_REASONS+=("${TEST_DEV} does not support atomic write")
> +		return 1
> +	fi
> +}
> +
>   _test_dev_queue_get() {
>   	if [[ $1 = scheduler ]]; then
>   		sed -e 's/.*\[//' -e 's/\].*//' "${TEST_DEV_SYSFS}/queue/scheduler"
> diff --git a/common/xfs b/common/xfs
> index 569770fecd53..0b1ca7c29049 100644
> --- a/common/xfs
> +++ b/common/xfs
> @@ -6,6 +6,22 @@
>   
>   . common/shellcheck
>   
> +_have_xfs_io_atomic_write() {
> +	local s
> +
> +	_have_program xfs_io || return $?
> +
> +	# If the pwrite command supports the -A option then this version
> +	# of xfs_io supports atomic writes.
> +	s=$(xfs_io -c help | grep pwrite | awk '{ print $4}')
> +	if [[ $s == *"A"* ]];
> +	then
> +		return 0
> +	fi
> +	SKIP_REASONS+=("xfs_io does not support the -A option")
> +	return 1
> +}
> +
>   _have_xfs() {
>   	_have_fs xfs && _have_program mkfs.xfs
>   }
> @@ -52,3 +68,45 @@ _xfs_run_fio_verify_io() {
>   
>   	return "${rc}"
>   }
> +
> +# Use xfs_io to perform a non-atomic write using pwritev2().
> +# Args:    $1 - device to write to
> +#          $2 - number of bytes to write
> +# Returns: Number of bytes written
> +run_xfs_io_pwritev2() {
> +	local dev=$1
> +	local bytes_to_write=$2
> +	local bytes_written
> +
> +	# Perform write and extract out bytes written from xfs_io output
> +	bytes_written=$(xfs_io -d -C \
> +		"pwrite -b ${bytes_to_write} -V 1 -D 0 ${bytes_to_write}" \
> +		"$dev" | grep "wrote" | sed 's/\// /g' | awk '{ print $2 }')
> +	echo "$bytes_written"
> +}
> +
> +# Use xfs_io to perform an atomic write using pwritev2().
> +# Args:    $1 - device to write to
> +#          $2 - number of bytes to write
> +# Returns: Number of bytes written
> +run_xfs_io_pwritev2_atomic() {
> +	local dev=$1
> +	local bytes_to_write=$2
> +	local bytes_written
> +
> +	# Perform atomic write and extract out bytes written from xfs_io output
> +	bytes_written=$(xfs_io -d -C \
> +		"pwrite -b ${bytes_to_write} -V 1 -A -D 0 ${bytes_to_write}" \
> +		"$dev" | grep "wrote" | sed 's/\// /g' | awk '{ print $2 }')
> +	echo "$bytes_written"
> +}
> +
> +run_xfs_io_xstat() {
> +	local dev=$1
> +	local field=$2
> +	local statx_output
> +
> +	statx_output=$(xfs_io -c "statx -r -m 0x00010000" "$dev" | \
> +		grep "$field" | awk '{ print $3 }')
> +	echo "$statx_output"
> +}
> diff --git a/tests/scsi/009 b/tests/scsi/009
> new file mode 100755
> index 000000000000..b114d92dd3db
> --- /dev/null
> +++ b/tests/scsi/009
> @@ -0,0 +1,229 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-3.0+
> +# Copyright (C) 2025 Oracle and/or its affiliates
> +#
> +# Test SCSI Atomic Writes with scsi_debug
> +
> +. tests/scsi/rc
> +. common/scsi_debug
> +. common/xfs
> +
> +DESCRIPTION="test scsi atomic writes"
> +QUICK=1
> +
> +requires() {
> +	_have_driver scsi_debug
> +	_have_xfs_io_atomic_write
> +}
> +
> +device_requires() {
> +	_require_device_support_atomic_writes
> +}
> +
> +fallback_device() {
> +	local scsi_debug_params=(
> +		delay=0
> +		atomic_wr=1
> +	)
> +	if ! _configure_scsi_debug "${scsi_debug_params[@]}"; then
> +		return 1
> +		fi
> +	echo "/dev/${SCSI_DEBUG_DEVICES[0]}"
> +}
> +
> +cleanup_fallback_device() {
> +	_exit_scsi_debug
> +}
> +
> +test_device() {
> +	local scsi_debug_atomic_wr_max_length
> +	local scsi_debug_atomic_wr_gran
> +	local scsi_atomic_max_bytes
> +	local scsi_atomic_min_bytes
> +	local sysfs_max_hw_sectors_kb
> +	local max_hw_bytes
> +	local sysfs_logical_block_size
> +	local sysfs_atomic_max_bytes
> +	local sysfs_atomic_unit_max_bytes
> +	local sysfs_atomic_unit_min_bytes
> +	local statx_atomic_min
> +	local statx_atomic_max
> +	local bytes_to_write
> +	local bytes_written
> +	local test_desc
> +
> +	echo "Running ${TEST_NAME}"
> +
> +	sysfs_logical_block_size=$(< "${TEST_DEV_SYSFS}"/queue/logical_block_size)
> +	sysfs_max_hw_sectors_kb=$(< "${TEST_DEV_SYSFS}"/queue/max_hw_sectors_kb)
> +	max_hw_bytes=$(( "$sysfs_max_hw_sectors_kb" * 1024 ))
> +	sysfs_atomic_max_bytes=$(< "${TEST_DEV_SYSFS}"/queue/atomic_write_max_bytes)
> +	sysfs_atomic_unit_max_bytes=$(< "${TEST_DEV_SYSFS}"/queue/atomic_write_unit_max_bytes)
> +	sysfs_atomic_unit_min_bytes=$(< "${TEST_DEV_SYSFS}"/queue/atomic_write_unit_min_bytes)
> +	scsi_debug_atomic_wr_max_length=$(< /sys/module/scsi_debug/parameters/atomic_wr_max_length)
> +	scsi_debug_atomic_wr_gran=$(< /sys/module/scsi_debug/parameters/atomic_wr_gran)
> +	scsi_atomic_max_bytes=$(( "$scsi_debug_atomic_wr_max_length" * "$sysfs_logical_block_size" ))
> +	scsi_atomic_min_bytes=$(( "$scsi_debug_atomic_wr_gran" * "$sysfs_logical_block_size" ))
> +
> +	test_desc="TEST 1 - Verify sysfs atomic attributes"
> +	if [ "$max_hw_bytes" -ge "$sysfs_atomic_max_bytes" ] &&
> +		[ "$sysfs_atomic_max_bytes" -ge "$sysfs_atomic_unit_max_bytes" ] &&
> +		[ "$sysfs_atomic_unit_max_bytes" -ge "$sysfs_atomic_unit_min_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $max_hw_bytes - $sysfs_max_hw_sectors_kb -" \
> +			"$sysfs_atomic_max_bytes - $sysfs_atomic_unit_max_bytes -" \
> +			"$sysfs_atomic_unit_min_bytes"
> +	fi
> +
> +	test_desc="TEST 2 - check scsi_debug atomic_wr_max_length is the same as sysfs atomic_write_max_bytes"
> +	if [ "$scsi_atomic_max_bytes" -le "$max_hw_bytes" ]
> +	then
> +		if [ "$scsi_atomic_max_bytes" = "$sysfs_atomic_max_bytes" ]
> +		then
> +			echo "$test_desc - pass"
> +		else
> +			echo "$test_desc - fail $scsi_atomic_max_bytes - $max_hw_bytes -" \
> +				"$sysfs_atomic_max_bytes"
> +		fi
> +	else
> +		if [ "$sysfs_atomic_max_bytes" = "$max_hw_bytes" ]
> +		then
> +			echo "$test_desc - pass"
> +		else
> +			echo "$test_desc - fail $scsi_atomic_max_bytes - $max_hw_bytes -" \
> +				"$sysfs_atomic_max_bytes"
> +		fi
> +	fi
> +
> +	test_desc="TEST 3 - check sysfs atomic_write_unit_max_bytes <= scsi_debug atomic_wr_max_length"
> +	if (("$sysfs_atomic_unit_max_bytes" <= "$scsi_atomic_max_bytes"))
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $sysfs_atomic_unit_max_bytes - $scsi_atomic_max_bytes"
> +	fi
> +
> +	test_desc="TEST 4 - check sysfs atomic_write_unit_min_bytes = scsi_debug atomic_wr_gran"
> +	if [ "$sysfs_atomic_unit_min_bytes" = "$scsi_atomic_min_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $sysfs_atomic_unit_min_bytes - $scsi_atomic_min_bytes"
> +	fi
> +
> +	test_desc="TEST 5 - check statx stx_atomic_write_unit_min"
> +	statx_atomic_min=$(run_xfs_io_xstat "$TEST_DEV" "stat.atomic_write_unit_min")
> +	if [ "$statx_atomic_min" = "$scsi_atomic_min_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $statx_atomic_min - $scsi_atomic_min_bytes"
> +	fi
> +
> +	test_desc="TEST 6 - check statx stx_atomic_write_unit_max"
> +	statx_atomic_max=$(run_xfs_io_xstat "$TEST_DEV" "stat.atomic_write_unit_max")
> +	if [ "$statx_atomic_max" = "$sysfs_atomic_unit_max_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $statx_atomic_max - $sysfs_atomic_unit_max_bytes"
> +	fi
> +
> +	test_desc="TEST 7 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes "
> +	test_desc+="with no RWF_ATOMIC flag - pwritev2 should be succesful"
> +	bytes_written=$(run_xfs_io_pwritev2 "$TEST_DEV" "$sysfs_atomic_unit_max_bytes")
> +	if [ "$bytes_written" = "$sysfs_atomic_unit_max_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $bytes_written - $sysfs_atomic_unit_max_bytes"
> +	fi
> +
> +	test_desc="TEST 8 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes with "
> +	test_desc+="RWF_ATOMIC flag - pwritev2 should be succesful"
> +	bytes_written=$(run_xfs_io_pwritev2_atomic "$TEST_DEV" "$sysfs_atomic_unit_max_bytes")
> +	if [ "$bytes_written" = "$sysfs_atomic_unit_max_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $bytes_written - $sysfs_atomic_unit_max_bytes"
> +	fi
> +
> +	test_desc="TEST 9 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes + 512 "
> +	test_desc+="bytes with no RWF_ATOMIC flag - pwritev2 should be succesful"
> +	bytes_to_write=$(( "${sysfs_atomic_unit_max_bytes}" + "$sysfs_logical_block_size" ))
> +	bytes_written=$(run_xfs_io_pwritev2 "$TEST_DEV" "$bytes_to_write")
> +	if [ "$bytes_written" = "$bytes_to_write" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $bytes_written - $bytes_to_write"
> +	fi
> +
> +	test_desc="TEST 10 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes + 512 "
> +	test_desc+="bytes with RWF_ATOMIC flag - pwritev2 should not be succesful"
> +	bytes_written=$(run_xfs_io_pwritev2_atomic "$TEST_DEV" "$bytes_to_write")
> +	if [ "$bytes_written" = "" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $bytes_written - $bytes_to_write"
> +	fi
> +
> +	test_desc="TEST 11 - perform a pwritev2 with size of sysfs_atomic_unit_min_bytes "
> +	test_desc+="with no RWF_ATOMIC flag - pwritev2 should be succesful"
> +	bytes_written=$(run_xfs_io_pwritev2 "$TEST_DEV" "$sysfs_atomic_unit_min_bytes")
> +	if [ "$bytes_written" = "$sysfs_atomic_unit_min_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $bytes_written - $scsi_atomic_min_bytes"
> +	fi
> +
> +	test_desc="TEST 12 - perform a pwritev2 with size of sysfs_atomic_unit_min_bytes "
> +	test_desc+="with RWF_ATOMIC flag - pwritev2 should be succesful"
> +	bytes_written=$(run_xfs_io_pwritev2_atomic "$TEST_DEV" "$sysfs_atomic_unit_min_bytes")
> +	if [ "$bytes_written" = "$sysfs_atomic_unit_min_bytes" ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		echo "$test_desc - fail $bytes_written - $scsi_atomic_min_bytes"
> +	fi
> +
> +	test_desc="TEST 13 - perform a pwritev2 with a size of sysfs_atomic_unit_min_bytes - 512 "
> +	test_desc+="bytes with no RWF_ATOMIC flag - pwritev2 should be succesful"

Again, I am not really sure that testing with RWF_ATOMIC has any value here.

> +	bytes_to_write=$(( "${sysfs_atomic_unit_min_bytes}" - "${sysfs_logical_block_size}" ))
> +	if [ "$bytes_to_write" = 0 ]
> +	then
> +		echo "$test_desc - pass"
> +		echo "pwrite: Invalid argument"
> +	else
> +		bytes_written=$(run_xfs_io_pwritev2 "$TEST_DEV" "$bytes_to_write")
> +		if [ "$bytes_written" = "$bytes_to_write" ]
> +		then
> +			echo "$test_desc - pass"
> +		else
> +			echo "$test_desc - fail $bytes_written - $bytes_to_write"
> +		fi
> +	fi
> +	test_desc="TEST 14 - perform a pwritev2 with a size of sysfs_atomic_unit_min_bytes - 512 "
> +	test_desc+="bytes with RWF_ATOMIC flag - pwritev2 should fail"
> +	if [ "$bytes_to_write" = 0 ]
> +	then
> +		echo "$test_desc - pass"
> +	else
> +		bytes_written=$(run_xfs_io_pwritev2_atomic "$TEST_DEV" "$bytes_to_write")
> +		if [ "$bytes_written" = "" ]
> +		then
> +			echo "$test_desc - pass"
> +		else
> +			echo "$test_desc - fail $bytes_written - $bytes_to_write"
> +		fi
> +	fi
> +
> +	_exit_scsi_debug
> +
> +	echo "Test complete"
> +}
> diff --git a/tests/scsi/009.out b/tests/scsi/009.out
> new file mode 100644
> index 000000000000..e31416b93515
> --- /dev/null
> +++ b/tests/scsi/009.out
> @@ -0,0 +1,18 @@
> +Running scsi/009
> +TEST 1 - Verify sysfs atomic attributes - pass
> +TEST 2 - check scsi_debug atomic_wr_max_length is the same as sysfs atomic_write_max_bytes - pass
> +TEST 3 - check sysfs atomic_write_unit_max_bytes <= scsi_debug atomic_wr_max_length - pass
> +TEST 4 - check sysfs atomic_write_unit_min_bytes = scsi_debug atomic_wr_gran - pass
> +TEST 5 - check statx stx_atomic_write_unit_min - pass
> +TEST 6 - check statx stx_atomic_write_unit_max - pass
> +TEST 7 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes with no RWF_ATOMIC flag - pwritev2 should be succesful - pass
> +TEST 8 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes with RWF_ATOMIC flag - pwritev2 should be succesful - pass
> +TEST 9 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes + 512 bytes with no RWF_ATOMIC flag - pwritev2 should be succesful - pass
> +pwrite: Invalid argument
> +TEST 10 - perform a pwritev2 with size of sysfs_atomic_unit_max_bytes + 512 bytes with RWF_ATOMIC flag - pwritev2 should not be succesful - pass
> +TEST 11 - perform a pwritev2 with size of sysfs_atomic_unit_min_bytes with no RWF_ATOMIC flag - pwritev2 should be succesful - pass
> +TEST 12 - perform a pwritev2 with size of sysfs_atomic_unit_min_bytes with RWF_ATOMIC flag - pwritev2 should be succesful - pass
> +TEST 13 - perform a pwritev2 with a size of sysfs_atomic_unit_min_bytes - 512 bytes with no RWF_ATOMIC flag - pwritev2 should be succesful - pass
> +pwrite: Invalid argument
> +TEST 14 - perform a pwritev2 with a size of sysfs_atomic_unit_min_bytes - 512 bytes with RWF_ATOMIC flag - pwritev2 should fail - pass
> +Test complete