selftests/filesystems: create get_unique_mnt_id() helper

Add helper to utils.c and use it in mount-notify and statmount tests.

Linking with utils.c drags in a dependecy with libcap, so add it to the
Makefile of the tests.

Reviewed-by: John Hubbard <[email protected]>
Signed-off-by: Amir Goldstein <[email protected]>
Link: https://lore.kernel.org/[email protected]
Reviewed-by: Christian Brauner <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

1 files changed, 2 insertions, 11 deletions

diff --git a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
index 4f0f325379b5..63ce708d93ed 100644
--- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
+++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
@@ -13,6 +13,7 @@
 
 #include "../../kselftest_harness.h"
 #include "../statmount/statmount.h"
+#include "../utils.h"
 
 // Needed for linux/fanotify.h
 #ifndef __kernel_fsid_t
@@ -23,16 +24,6 @@ typedef struct {
 
 #include <sys/fanotify.h>
 
-static uint64_t get_mnt_id(struct __test_metadata *const _metadata,
-			   const char *path)
-{
-	struct statx sx;
-
-	ASSERT_EQ(statx(AT_FDCWD, path, 0, STATX_MNT_ID_UNIQUE, &sx), 0);
-	ASSERT_TRUE(!!(sx.stx_mask & STATX_MNT_ID_UNIQUE));
-	return sx.stx_mnt_id;
-}
-
 static const char root_mntpoint_templ[] = "/tmp/mount-notify_test_root.XXXXXX";
 
 static const int mark_cmds[] = {
@@ -81,7 +72,7 @@ FIXTURE_SETUP(fanotify)
 
 	ASSERT_EQ(mkdir("b", 0700), 0);
 
-	self->root_id = get_mnt_id(_metadata, "/");
+	self->root_id = get_unique_mnt_id("/");
 	ASSERT_NE(self->root_id, 0);
 
 	for (i = 0; i < NUM_FAN_FDS; i++) {