[PATCH blktests v3 3/6] common: add and use min io for fio

[Luis Chamberlain <mcgrof@kernel.org>]

When using fio we should not issue IOs smaller than the device supports.
Today a lot of places have in place 4k, but soon we will have devices
which support bs > ps. For those devices we should check the minimum
supported IO.

However, since we also have a min optimal IO, we might as well use that
as well. By using this we can also leverage the same lookup with stat
whether or not the target file is a block device or a file.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 common/fio | 26 ++++++++++++++++++++++++--
 common/rc  | 24 ++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/common/fio b/common/fio
index b9ea087fc6c5..d147214f3d16 100644
--- a/common/fio
+++ b/common/fio
@@ -189,15 +189,37 @@ _run_fio() {
 	return $rc
 }
 
+_fio_opts_to_min_io() {
+	local arg path
+	local -i min_io=4096
+
+        for arg in "$@"; do
+		[[ "$arg" =~ ^--filename= || "$arg" =~ --directory= ]] || continue
+		path="${arg##*=}"
+		min_io=$(_min_io "$path")
+		# Keep 4K minimum IO size for historical consistency
+		((min_io < 4096)) && min_io=4096
+		break
+	done
+
+	echo "$min_io"
+}
+
 # Wrapper around _run_fio used if you need some I/O but don't really care much
 # about the details
 _run_fio_rand_io() {
-	_run_fio --bs=4k --rw=randread --norandommap --numjobs="$(nproc)" \
+	local bs
+
+	bs=$(_fio_opts_to_min_io "$@") || return 1
+	_run_fio --bs="$bs" --rw=randread --norandommap --numjobs="$(nproc)" \
 		--name=reads --direct=1 "$@"
 }
 
 _run_fio_verify_io() {
-	_run_fio --name=verify --rw=randwrite --direct=1 --ioengine=libaio --bs=4k \
+	local bs
+
+	bs=$(_fio_opts_to_min_io "$@") || return 1
+	_run_fio --name=verify --rw=randwrite --direct=1 --ioengine=libaio --bs="$bs" \
 		--iodepth=16 --verify=crc32c --verify_state_save=0 "$@"
 }
 
diff --git a/common/rc b/common/rc
index a7e899cfb419..6e7bddc844bf 100644
--- a/common/rc
+++ b/common/rc
@@ -400,6 +400,30 @@ _test_dev_is_partition() {
 	[[ -n ${TEST_DEV_PART_SYSFS} ]]
 }
 
+_min_io() {
+	local path_or_dev=$1
+	local min_io=4096
+	if [ -z "$path_or_dev" ]; then
+		echo "path for min_io does not exist"
+		return 1
+	fi
+
+	if [ -c "$path_or_dev" ]; then
+		if [[ "$path_or_dev" == /dev/ng* ]]; then
+			path_or_dev="${path_or_dev/ng/nvme}"
+		fi
+	fi
+
+	if [ -e "$path_or_dev" ]; then
+		min_io=$(stat --printf=%o "$path_or_dev")
+		((min_io < 4096)) && min_io=4096
+		echo "$min_io"
+	else
+		echo "Error: '$path_or_dev' does not exist or is not accessible"
+		return 1
+	fi
+}
+
 # Return max open zones or max active zones of the test target device.
 # If the device has both, return smaller value.
 _test_dev_max_open_active_zones() {
-- 
2.45.2