Re: [PATCH] selftests: Add kselftest framework to the testfile

[Shuah Khan <skhan@linuxfoundation.org>]

On 10/24/24 10:55, Shivam Chaudhary wrote:
> This patch updates the existing test that checks
> for `open(O_TMPFILE)` and `linkat()` behaviors in
> mount namespaces to use the kselftest framework.
> 
> This includes the following changes:
> 
> - Replaced direct error handling with
>   `ksft_test_result_*` macros for better reporting
>    of test outcomes.

Replace

> 
> - Added `ksft_print_header()` and `ksft_set_plan()`
>   to structure test outputs more effectively.
> 
> - Introduced the helper function `is_unshare()` to
>    handle unshare-related checks.
> 

Introduce

> - Improved the test flow by adding more detailed pass/fail
>    reporting for unshare, mounting, file opening, and linking
>    operations.

Improve

> 
> - Skips the test if it's not run as root, providing an
>    appropriate Warning.

Check submitting patches document for details how to write
short log and change log that hep reviewers.

Also - you haven't cc'ed the right mailing lists. Send v2
cc'ing kselftest mailing list and correcting the short
log and change log problems.


> 
> Test logs:
> 
> Before change:
> 
> - Withou root
>   error: unshare, errno 1
> 
> - With root
>   No, output
> 
> After change:
> 
> - Without root
>   TAP version 13
>   1..1
>   ok 1 # SKIP This test needs root to ru
> 
> - With root
>   TAP version 13
>   1..1
>   ok 1 unshare(): we have a new mount namespace.
>   1..2
>   ok 2 mount(): Root filesystem private mount: Success
>   1..3
>   ok 3 mount(): Mounting tmpfs on /tmp: Success
>   1..4
>   ok 4 openat(): Open first temporary file: Success
>   1..5
>   ok 5 linkat(): Linking the temporary file: Success
>   1..6
>   ok 6 openat(): Opening the second temporary file: Success
>   # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0
> 
> Signed-off-by: Shivam Chaudhary <cvam0000@gmail.com>
> ---
>   .../selftests/tmpfs/bug-link-o-tmpfile.c      | 72 +++++++++++++++----
>   1 file changed, 58 insertions(+), 14 deletions(-)
> 
> diff --git a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
> index b5c3ddb90942..26dea19c1614 100644
> --- a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
> +++ b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
> @@ -23,45 +23,89 @@
>   #include <sys/mount.h>
>   #include <unistd.h>
>   
> -int main(void)
> -{
> -	int fd;
> +#include "../kselftest.h"
>   
> -	if (unshare(CLONE_NEWNS) == -1) {
> +static int is_unshare(int flag)
> +{
> +	if (unshare(flag) == -1) {
>   		if (errno == ENOSYS || errno == EPERM) {
> -			fprintf(stderr, "error: unshare, errno %d\n", errno);
> -			return 4;
> +			ksft_test_result_fail("error: unshare, errno %d\n", errno);
> +			return -1; // Return -1 for failure
>   		}
>   		fprintf(stderr, "error: unshare, errno %d\n", errno);
> +		return -1;
> +	}
> +
> +	return 0; // Return 0 for success
> +}
> +
> +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_test_result_skip("This test needs root to run!\n");
>   		return 1;
>   	}
> -	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
> -		fprintf(stderr, "error: mount '/', errno %d\n", errno);
> +
> +	if (is_unshare(CLONE_NEWNS) == 0) {
> +		ksft_test_result_pass("unshare(): we have a new mount namespace.\n");
> +	} else {
> +		ksft_test_result_fail("unshare(): failed\n");
>   		return 1;
>   	}
>   
> +	ksft_set_plan(2);
> +
> +	if (mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL) == -1) {
> +		ksft_test_result_fail("mount(): Root filesystem private mount: Fail %d\n", errno);
> +		return 1;
> +	} else {
> +		ksft_test_result_pass("mount(): Root filesystem private mount: Success\n");
> +	}
> +
> +	ksft_set_plan(3);
>   	/* Our heroes: 1 root inode, 1 O_TMPFILE inode, 1 permanent inode. */
>   	if (mount(NULL, "/tmp", "tmpfs", 0, "nr_inodes=3") == -1) {
> -		fprintf(stderr, "error: mount tmpfs, errno %d\n", errno);
> +		ksft_test_result_fail("mount(): Mounting tmpfs on /tmp: Fail %d\n", errno);
>   		return 1;
> +	} else {
> +		ksft_test_result_pass("mount(): Mounting tmpfs on /tmp: Success\n");
>   	}
>   
> -	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
> +	ksft_set_plan(4);
> +	fd = openat(AT_FDCWD, "/tmp", O_WRONLY | O_TMPFILE, 0600);
>   	if (fd == -1) {
> -		fprintf(stderr, "error: open 1, errno %d\n", errno);
> +		ksft_test_result_fail("openat(): Open first temporary file: Fail %d\n", errno);
>   		return 1;
> +	} else {
> +		ksft_test_result_pass("openat(): Open first temporary file: Success\n");
>   	}
> +
> +	ksft_set_plan(5);
>   	if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) {
> -		fprintf(stderr, "error: linkat, errno %d\n", errno);
> +		ksft_test_result_fail("linkat(): Linking the temporary file: Fail %d\n", errno);
> +		close(fd); // Ensure fd is closed on failure
>   		return 1;
> +	} else {
> +		ksft_test_result_pass("linkat(): Linking the temporary file: Success\n");
>   	}
>   	close(fd);
>   
> -	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
> +	ksft_set_plan(6);
> +	fd = openat(AT_FDCWD, "/tmp", O_WRONLY | O_TMPFILE, 0600);
>   	if (fd == -1) {
> -		fprintf(stderr, "error: open 2, errno %d\n", errno);
> +		ksft_test_result_fail("openat(): Opening the second temporary file: Fail %d\n", errno);
>   		return 1;
> +	} else {
> +		ksft_test_result_pass("openat(): Opening the second temporary file: Success\n");
>   	}
>   
> +	ksft_exit_pass();
>   	return 0;
>   }