Re: [PATCH v3] selftests: tmpfs: Add kselftest support to tmpfs

[Shuah Khan <skhan@linuxfoundation.org>]

On 10/28/24 12:57, Shivam Chaudhary wrote:
> Add kselftest support for openat, linkat, unshare, mount tests

You are combining a few too many changes in this patch. As such
this patch doesn't add support for the above tests. Instead it
changes the reporting to use ksft_* framework.

> 
> - Replace direct error handling with
>   'ksft_test_result_*' , 'ksft_print_msg' macros for better
>   reporting.
> 

That
> - Add `ksft_print_header()` and `ksft_set_plan()`
>   to structure test outputs more effectively.
> 
> - Improve the test flow by adding more detailed pass/fail
>    reporting for unshare, mounting, file opening, and linking
>    operations.
> 
> - Skip the test if it's not run as root, providing an
>    appropriate Warning.

Make this a separate patch and the very first patch in the series.

> 
>    Test logs:
> 
> Before change:
> 
> - Without 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 run
> 
> - With root
>   TAP version 13
> 1..1
>    unshare(): Creat new mount namespace: Success.
>    mount(): Root filesystem private mount: Success
>    mount(): Mounting tmpfs on /tmp: Success
>    openat(): Open first temporary file: Success
>    linkat(): Linking the temporary file: Success
>    openat(): Opening the second temporary file: Success
>    ok 1 Test : Success
>    Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
> 
> Signed-off-by: Shivam Chaudhary <cvam0000@gmail.com>
> ---
> 
> Notes:
> 		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
> 
>   .../selftests/tmpfs/bug-link-o-tmpfile.c      | 69 +++++++++++++++----
>   1 file changed, 57 insertions(+), 12 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..9ca1245784d9 100644
> --- a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
> +++ b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c
> @@ -23,45 +23,90 @@
>   #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_test_result_skip("This test needs root to run!\n");
> +		return 1;

This should be SKIP - simply use KSFT_SKIP

> +	}
> +
> +
>   	if (unshare(CLONE_NEWNS) == -1) {
>   		if (errno == ENOSYS || errno == EPERM) {
> -			fprintf(stderr, "error: unshare, errno %d\n", errno);
> -			return 4;
> +			ksft_test_result_fail("unshare() error: unshare, errno %d\n", errno);

This isn't a failure - it just means that unsaher() might not be supported.
Since root check is already done, EPERM won't be returned here.

> +			return 1;

Okay this wrong. This changes the return value fro 4 to 1 - SKIP becomes fail.
Use KSFT_SKIP


>   		}
> -		fprintf(stderr, "error: unshare, errno %d\n", errno);
> -		return 1;
> +		else{
> +			fprintf(stderr, "unshare() error: unshare, errno %d\n", errno);
> +			ksft_test_result_fail("unshare() error: unshare, errno %d\n", errno);
> +			return 1;
> +
> +		}
> +	}
> +	
> +	else {
> +		ksft_print_msg("unshare(): Creat new mount namespace: Success.\n");
> +
>   	}
> -	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
> -		fprintf(stderr, "error: mount '/', errno %d\n", errno);
> +
> +
> +
> +	if (mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL) == -1) {
> +		ksft_test_result_fail("mount() error: Root filesystem private mount: Fail %d\n", errno);
>   		return 1;
> +	} else {
> +		ksft_print_msg("mount(): Root filesystem private mount: Success\n");
>   	}
>   
> +
>   	/* 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() error: Mounting tmpfs on /tmp: Fail %d\n", errno);
>   		return 1;
> +	} else {
> +		ksft_print_msg("mount(): Mounting tmpfs on /tmp: Success\n");
>   	}
>   
> -	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
> +
> +	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() error: Open first temporary file: Fail %d\n", errno);
>   		return 1;
> +	} else {
> +		ksft_print_msg("openat(): Open first temporary file: Success\n");
>   	}
> +
> +
>   	if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) {
> -		fprintf(stderr, "error: linkat, errno %d\n", errno);
> +		ksft_test_result_fail("linkat() error: Linking the temporary file: Fail %d\n", errno);
> +		/* Ensure fd is closed on failure */
> +		close(fd);
>   		return 1;
> +	} else {
> +		ksft_print_msg("linkat(): Linking the temporary file: Success\n");
>   	}
>   	close(fd);
>   
> -	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
> +
> +	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() error: Opening the second temporary file: Fail %d\n", errno);
>   		return 1;
> +	} else {
> +		ksft_print_msg("openat(): Opening the second temporary file: Success\n");
>   	}
>   
> +    ksft_test_result_pass("Test : Success\n");
> +	ksft_exit_pass();
>   	return 0;
>   }


Fix these and split the patches. It makes it easier to review.

thanks,
-- Shuah