btrfs-progs: tests: add case for scrub limit

Signed-off-by: David Sterba <dsterba@suse.com>

tests/cli-tests/024-scrub-limit/test.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+# Read scrub limits on a filesystem
+
+source "$TEST_TOP/common" || exit
+
+setup_root_helper
+setup_loopdevs 4
+prepare_loopdevs
+TEST_DEV=${loopdevs[1]}
+
+fsid="13411a59-ccea-4296-a6f8-1446ccf8c9be"
+sysfs="/sys/fs/btrfs/13411a59-ccea-4296-a6f8-1446ccf8c9be"
+
+run_check $SUDO_HELPER "$TOP/mkfs.btrfs" -f --uuid "$fsid" -d raid1 -m raid1 "${loopdevs[@]}"
+run_check_mount_test_dev
+for i in "$sysfs"/devinfo/*/scrub_speed_max; do
+	if ! [ -f "$i" ]; then
+		_log "sysfs file scrub_speed_max not available, skip setting limits"
+		break;
+	fi
+	run_check cat "$i"
+	echo "10m" | run_check $SUDO_HELPER tee "$i" >/dev/null
+done
+# This works even if scrub_speed_max files don't exist, this is equivalent to unlimited
+run_check "$TOP/btrfs" scrub limit "$TEST_MNT"
+run_check_umount_test_dev
+
+cleanup_loopdevs