[btrfs-progs PATCHv3 1/3] tests: common: Add check_dm_target_support helper

[Marcos Paulo de Souza <marcos.souza.org@gmail.com>]

From: Marcos Paulo de Souza <mpdesouza@suse.com>

This function will be used later to test if dm-thin is supported.
Inspired by fstests.

Suggested-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
 tests/common | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tests/common b/tests/common
index ca098444..3ea8c260 100644
--- a/tests/common
+++ b/tests/common
@@ -322,6 +322,21 @@ check_global_prereq()
 	fi
 }
 
+# check if the targets passed as arguments are available, and if not just skip
+# the test
+check_dm_target_support()
+{
+	setup_root_helper
+
+	for target in "$@"; do
+		$SUDO_HELPER modprobe dm-$target >/dev/null 2>&1
+		$SUDO_HELPER dmsetup targets 2>&1 | grep -q ^$target
+		if [ $? -ne 0 ]; then
+			_not_run "This test requires dm $target support."
+		fi
+	done
+}
+
 check_image()
 {
 	local image
-- 
2.24.0