btrfs-progs: tests: skip tests if dmsetup is not available

Move the check of dmsetup to check_dm_target_support, and adapt the only
two places checking if dmsetup is present in the system. Now we skip the
tests if dmsetup isn't available, instead of marking the test as failed.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

tests/common

@@ -328,11 +328,17 @@ check_global_prereq()
 	fi
 }
 
-# Check if the targets passed as arguments are available, and if not just skip
-# the test
+# Check if dmsetup and targets passed as arguments are available, and skip the
+# test if they aren't
 check_dm_target_support()
 {
 	setup_root_helper
+
+	which dmsetup &> /dev/null
+	if [ $? -ne 0 ]; then
+		_not_run "This test requires dmsetup tool";
+	fi
+
 	for target in "$@"; do
 		$SUDO_HELPER modprobe "dm-$target" >/dev/null 2>&1
 		$SUDO_HELPER dmsetup targets 2>&1 | grep -q "^$target"

tests/mkfs-tests/005-long-device-name-for-ssd/test.sh

@@ -4,7 +4,6 @@
 source "$TEST_TOP/common"
 
 check_prereq mkfs.btrfs
-check_global_prereq dmsetup
 check_dm_target_support linear
 
 setup_root_helper

tests/mkfs-tests/017-small-backing-size-thin-provision-device/test.sh

@@ -6,7 +6,6 @@ source "$TEST_TOP/common"
 
 check_prereq mkfs.btrfs
 check_global_prereq udevadm
-check_global_prereq dmsetup
 check_dm_target_support linear thin
 
 setup_root_helper