main - tests: Support multiple backing devices

[David Teigland <teigland@sourceware.org>]

Gitweb:        https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=759b0392d5f0f15e7e503ae1b3ef82ea7b4df0c1
Commit:        759b0392d5f0f15e7e503ae1b3ef82ea7b4df0c1
Parent:        c64dbc7ee80963a02f82f3257963f90b471fa90e
Author:        Leo Yan <leo.yan@linaro.org>
AuthorDate:    Thu Jun 3 17:59:10 2021 +0800
Committer:     David Teigland <teigland@redhat.com>
CommitterDate: Thu Jun 3 09:39:32 2021 -0500

tests: Support multiple backing devices

In current implementation, the option "LVM_TEST_BACKING_DEVICE" only
supports to specify one backing device; this patch is to extend the
option to support multiple backing devices by using comma as separator,
e.g. below command specifies two backing devices:

  make check_lvmlockd_idm LVM_TEST_BACKING_DEVICE=/dev/sdj3,/dev/sdk3

This can allow the testing works on multiple drives and verify the
locking scheme if can work as expected for multiple drives case.  For
example, for Seagate IDM locking scheme, if a VG uses two PVs, every PV
is resident on a drive, thus the locking operations will be sent to two
drives respectively; so the extension for "LVM_TEST_BACKING_DEVICE" can
help to verify different drive configurations for locking.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 test/lib/aux.sh | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/test/lib/aux.sh b/test/lib/aux.sh
index 97c7ac68b..a592dad81 100644
--- a/test/lib/aux.sh
+++ b/test/lib/aux.sh
@@ -901,11 +901,22 @@ prepare_backing_dev() {
 	local size=${1=32}
 	shift
 
+	if test -n "$LVM_TEST_BACKING_DEVICE"; then
+		IFS=',' read -r -a BACKING_DEVICE_ARRAY <<< "$LVM_TEST_BACKING_DEVICE"
+
+		for d in "${BACKING_DEVICE_ARRAY[@]}"; do
+			if test ! -b "$d"; then
+				echo "Device $d doesn't exist!"
+				return 1
+			fi
+		done
+	fi
+
 	if test -f BACKING_DEV; then
 		BACKING_DEV=$(< BACKING_DEV)
 		return 0
-	elif test -b "$LVM_TEST_BACKING_DEVICE"; then
-		BACKING_DEV=$LVM_TEST_BACKING_DEVICE
+	elif test -n "$LVM_TEST_BACKING_DEVICE"; then
+		BACKING_DEV=${BACKING_DEVICE_ARRAY[0]}
 		echo "$BACKING_DEV" > BACKING_DEV
 		return 0
 	elif test "${LVM_TEST_PREFER_BRD-1}" = "1" && \
@@ -953,7 +964,14 @@ prepare_devs() {
 		local dev="$DM_DEV_DIR/mapper/$name"
 		DEVICES[$count]=$dev
 		count=$((  count + 1 ))
-		echo 0 $size linear "$BACKING_DEV" $(( ( i - 1 ) * size + ( header_shift * 2048 ) )) > "$name.table"
+		# If the backing device number can meet the requirement for PV devices,
+		# then allocate a dedicated backing device for PV; otherwise, rollback
+		# to use single backing device for device-mapper.
+		if [ -n "$LVM_TEST_BACKING_DEVICE" ] && [ $n -le ${#BACKING_DEVICE_ARRAY[@]} ]; then
+			echo 0 $size linear "${BACKING_DEVICE_ARRAY[$(( count - 1 ))]}" $(( header_shift * 2048 )) > "$name.table"
+		else
+			echo 0 $size linear "$BACKING_DEV" $(( ( i - 1 ) * size + ( header_shift * 2048 ) )) > "$name.table"
+		fi
 		dmsetup create -u "TEST-$name" "$name" "$name.table" || touch CREATE_FAILED &
 		test -f CREATE_FAILED && break;
 	done
@@ -971,6 +989,13 @@ prepare_devs() {
 		return $?
 	fi
 
+	for d in "${BACKING_DEVICE_ARRAY[@]}"; do
+		cnt=$((`blockdev --getsize64 $d` / 1024 / 1024))
+		cnt=$(( cnt < 1000 ? cnt : 1000 ))
+		dd if=/dev/zero of="$d" bs=1MB count=$cnt
+		wipefs -a "$d" 2>/dev/null || true
+	done
+
 	# non-ephemeral devices need to be cleared between tests
 	test -f LOOP -o -f RAMDISK || for d in "${DEVICES[@]}"; do
 		# ensure disk header is always zeroed