common/null_blk: introduce _have_null_blk_feature

Introduce a helper function _have_null_blk_feature which checks /sys/kernel/config/features. It allows test cases to adapt to null_blk feature support status. Reviewed-by: Chaitanya Kulkarni <[email protected]> Signed-off-by: Shin'ichiro Kawasaki <[email protected]>
osandov · Jan 23, 2024 · 4e10207 · 4e10207
1 parent f7977df
commit 4e10207
Showing 1 changed file with 15 additions and 0 deletions.
diff --git a/common/null_blk b/common/null_blk
@@ -10,6 +10,21 @@ _have_null_blk() {
 	_have_driver null_blk
 }
 
+_have_null_blk_feature() {
+	# Ensure that null_blk driver is built-in or loaded
+	if ! [[ -d /sys/module/null_blk ]]; then
+		if ! modprobe -q null_blk; then
+			return 1
+		fi
+		if [[ ! "${MODULES_TO_UNLOAD[*]}" =~ null_blk ]]; then
+			MODULES_TO_UNLOAD+=(null_blk)
+		fi
+	fi
+
+	# Check that null_blk has the specified feature
+	grep -qe "$1" /sys/kernel/config/nullb/features
+}
+
 _remove_null_blk_devices() {
 	if [[ -d /sys/kernel/config/nullb ]]; then
 		find /sys/kernel/config/nullb -mindepth 1 -maxdepth 1 \