From c8d8032c15da42c20bd7eebbac929955eea7634c Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov@fb.com>
Date: Tue, 15 Aug 2017 22:36:43 -0700
Subject: [PATCH] common/scsi_debug: make helpers more useful

Generalize the helpers to make them more useful: instead of always
setting up one device, it now takes arbitrary module parameters and sets
up as many devices as requested.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 common/scsi_debug | 44 ++++++++++++++++++++++++++++++++------------
 tests/block/001   | 21 +++++++--------------
 tests/block/002   | 12 ++++++------
 3 files changed, 45 insertions(+), 32 deletions(-)

diff --git a/common/scsi_debug b/common/scsi_debug
index 23c9038..345d16d 100644
--- a/common/scsi_debug
+++ b/common/scsi_debug
@@ -21,27 +21,47 @@ _have_scsi_debug() {
 	_have_module scsi_debug
 }
 
-_get_scsi_debug_dev() {
-	modprobe -r scsi_debug
-	if ! modprobe scsi_debug; then
+_init_scsi_debug() {
+	if ! modprobe -r scsi_debug || ! modprobe scsi_debug "$@"; then
 		return 1
 	fi
 
 	udevadm settle
 
-	local dev
-	for dev in /sys/block/sd*; do
-		if [[ "$(cat "${dev}/device/model")" =~ ^scsi_debug[[:space:]]*$ ]]; then
-			SCSI_DEBUG_NAME="${dev#/sys/block}"
-			SCSI_DEBUG_DEV="/dev/${SCSI_DEBUG_NAME}"
-			return 0
+	local host_sysfs host target_sysfs target
+	SCSI_DEBUG_HOSTS=()
+	SCSI_DEBUG_TARGETS=()
+	SCSI_DEBUG_DEVICES=()
+	for host_sysfs in /sys/class/scsi_host/*; do
+		if [[ "$(cat "${host_sysfs}/proc_name")" = scsi_debug ]]; then
+			host="${host_sysfs#/sys/class/scsi_host/host}"
+			SCSI_DEBUG_HOSTS+=("$host")
+			for target_sysfs in /sys/class/scsi_device/"$host":*; do
+				target="${target_sysfs#/sys/class/scsi_device/}"
+				SCSI_DEBUG_TARGETS+=("$target")
+				SCSI_DEBUG_DEVICES+=("$(ls "$target_sysfs/device/block")")
+			done
 		fi
 	done
 
-	echo "Could not get scsi_debug device" >&2
-	return 1
+	if [[ ${#SCSI_DEBUG_HOSTS[@]} -eq 0 ]]; then
+		echo "Could not find scsi_debug hosts" >&2
+		_exit_scsi_debug
+		return 1
+	fi
+
+	if [[ ${#SCSI_DEBUG_TARGETS[@]} -eq 0 ]]; then
+		echo "Could not find scsi_debug targets" >&2
+		_exit_scsi_debug
+		return 1
+	fi
+
+	return 0
 }
 
-_put_scsi_debug_dev() {
+_exit_scsi_debug() {
+	unset SCSI_DEBUG_HOSTS
+	unset SCSI_DEBUG_TARGETS
+	unset SCSI_DEBUG_DEVICES
 	modprobe -r scsi_debug
 }
diff --git a/tests/block/001 b/tests/block/001
index 4b11dbb..7411a0c 100755
--- a/tests/block/001
+++ b/tests/block/001
@@ -29,20 +29,12 @@ requires() {
 }
 
 stress_scsi_debug() {
-	modprobe -r scsi_debug
-	modprobe scsi_debug "$@"
+	if ! _init_scsi_debug "$@"; then
+		return
+	fi
 
-	targets=()
-	for host in /sys/class/scsi_host/*; do
-		if [[ "$(cat "${host}/proc_name")" = scsi_debug ]]; then
-			host="$(basename "${host}")"
-			for target in "/sys/class/scsi_device/${host#host}:"*; do
-				targets+=("$(basename "${target}")")
-			done
-		fi
-	done
-
-	for target in "${targets[@]}"; do
+	local host target
+	for target in "${SCSI_DEBUG_TARGETS[@]}"; do
 		(
 		host="${target%%:*}"
 		scan="${target#*:}"
@@ -57,7 +49,8 @@ stress_scsi_debug() {
 	touch "$TMPDIR/stop"
 	wait
 	rm -f "$TMPDIR/stop"
-	modprobe -r scsi_debug
+
+	_exit_scsi_debug
 }
 
 test() {
diff --git a/tests/block/002 b/tests/block/002
index 310e866..57b4f89 100755
--- a/tests/block/002
+++ b/tests/block/002
@@ -30,22 +30,22 @@ requires() {
 test() {
 	echo "Running ${TEST_NAME}"
 
-	if ! _get_scsi_debug_dev; then
+	if ! _init_scsi_debug; then
 		return 1
 	fi
 
-	blktrace -D "$TMP_DIR" "$SCSI_DEBUG_DEV" >"$FULL" 2>&1 &
+	blktrace -D "$TMP_DIR" "/dev/${SCSI_DEBUG_DEVICES[0]}" >"$FULL" 2>&1 &
 	sleep 0.5
-	echo 1 > "/sys/block/${SCSI_DEBUG_NAME}/device/delete"
-	if [[ ! -d /sys/kernel/debug/block/${SCSI_DEBUG_NAME} ]]; then
+	echo 1 > "/sys/block/${SCSI_DEBUG_DEVICES[0]}/device/delete"
+	if [[ ! -d /sys/kernel/debug/block/${SCSI_DEBUG_DEVICES[0]} ]]; then
 		echo "debugfs directory deleted with blktrace active"
 	fi
 	{ kill $!; wait; } >/dev/null 2>/dev/null
-	if [[ -d /sys/kernel/debug/block/${SCSI_DEBUG_NAME} ]]; then
+	if [[ -d /sys/kernel/debug/block/${SCSI_DEBUG_DEVICES[0]} ]]; then
 		echo "debugfs directory leaked"
 	fi
 
-	_put_scsi_debug_dev
+	_exit_scsi_debug
 
 	echo "Test complete"
 }
-- 
2.51.0