[PATCH v4 1/2] selftests:tmpfs: Add Skip test if not run as root

[Shivam Chaudhary <cvam0000@gmail.com>]

- Add skip test if  not run as root, with an
  appropriate Warning.

- Add 'ksft_print_header()' and 'ksft_set_plan()'
 to structure test outputs more effectively.

Test logs :

Before change:

- Without root
 error: unshare, errno 1

- With root
 No, output

After change:

- Without root
TAP version 13
1..1

- With root
TAP version 13
1..1

Signed-off-by: Shivam Chaudhary <cvam0000@gmail.com>
---

Notes:

		Changes in v4 1/2: 
				- Start a patchset
				- Split patch into smaller pathes to make it easy to review.
		
		link to v3: https://lore.kernel.org/all/20241028185756.111832-1-cvam0000@gmail.com/

		Changes in v3:
				- Remove extra ksft_set_plan()
				- Remove function for unshare()
				- Fix the comment style

		link to v2: https://lore.kernel.org/all/20241026191621.2860376-1-cvam0000@gmail.com/

		Changes in v2:
				- Make the commit message more clear.

		link to v1: https://lore.kernel.org/all/20241024200228.1075840-1-cvam0000@gmail.com/T/#u



 tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
index b5c3ddb90942..cdab1e8c0392 100644
--- a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
+++ b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
@@ -23,10 +23,23 @@
 #include <sys/mount.h>
 #include <unistd.h>
 
+#include "../kselftest.h"
+
 int main(void)
 {
 	int fd;
 
+	/* Setting up kselftest framework */
+	ksft_print_header();
+	ksft_set_plan(1);
+
+	/* Check if test is run as root */
+	if (geteuid()) {
+		ksft_print_msg("Skip : Need to run as root");
+		exit(KSFT_SKIP);
+
+	}
+
 	if (unshare(CLONE_NEWNS) == -1) {
 		if (errno == ENOSYS || errno == EPERM) {
 			fprintf(stderr, "error: unshare, errno %d\n", errno);
-- 
2.45.2