[LTP] [PATCH 1/5] fanotify13: Verify that we did not get an extra event

[Petr Vorel]

Hi Amir, all,

> For example, verify that we did not get an event on a directory object
> without requesting FAN_ONDIR.  Also, report a test failure if no events
> received at all instead of blocking on read of fanotify_fd.

> With this change, the test fails with overlayfs variants over btrfs,
> because the size of fid of overalyfs over btrfs is about 90 bytes and
> the events on the three objects do not all fit into a single 256 bytes
> buffer read. Increase the size of the events buffer to fix this failure.

> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
>  .../kernel/syscalls/fanotify/fanotify13.c     | 22 ++++++++++++++++---
>  1 file changed, 19 insertions(+), 3 deletions(-)

> diff --git a/testcases/kernel/syscalls/fanotify/fanotify13.c b/testcases/kernel/syscalls/fanotify/fanotify13.c
> index 5cd857707..16fd99ba1 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify13.c
> +++ b/testcases/kernel/syscalls/fanotify/fanotify13.c
> @@ -34,7 +34,7 @@
>  #include "fanotify.h"

>  #define PATH_LEN 128
> -#define BUF_SIZE 256
> +#define BUF_SIZE 1024
>  #define DIR_ONE "dir_one"
>  #define FILE_ONE "file_one"
>  #define FILE_TWO "file_two"
> @@ -130,10 +130,15 @@ static int setup_marks(unsigned int fd, struct test_case_t *tc)
>  		SAFE_FANOTIFY_MARK(fd, FAN_MARK_ADD | mark->flag, tc->mask,
>  				   AT_FDCWD, objects[i].path);

> -		/* Setup the expected mask for each generated event */
> +		/*
> +		 * Setup the expected mask for each generated event.
> +		 * No events are expected on directory without FAN_ONDIR.
> +		 */
>  		event_set[i].expected_mask = tc->mask;
>  		if (!objects[i].is_dir)
>  			event_set[i].expected_mask &= ~FAN_ONDIR;
> +		else if (!(event_set[i].expected_mask & FAN_ONDIR))
> +			event_set[i].expected_mask = 0;
>  	}
>  	return 0;
>  }
> @@ -163,7 +168,8 @@ static void do_test(unsigned int number)
>  		return;
>  	}

> -	fanotify_fd = SAFE_FANOTIFY_INIT(FAN_CLASS_NOTIF | FAN_REPORT_FID, O_RDONLY);
> +	fanotify_fd = SAFE_FANOTIFY_INIT(FAN_CLASS_NOTIF | FAN_REPORT_FID |
> +					 FAN_NONBLOCK, O_RDONLY);

>  	/*
>  	 * Place marks on a set of objects and setup the expected masks
> @@ -279,6 +285,16 @@ static void do_test(unsigned int number)
>  			FSID_VAL_MEMBER(event_fid->fsid, 1),
>  			*(unsigned long *) event_file_handle->f_handle);
>  	}
> +
> +	/*
> +	 * Verify that we did not get an extra event, for example, that we did
> +	 * not get an event on directory without FAN_ONDIR.
> +	 */
> +	if (event_set[i].expected_mask) {
> +		tst_res(TFAIL,
> +			"Did not get an expected event (expected: %llx)",
> +			event_set[i].expected_mask);

I verified that on openSUSE on x86_64 test properly fails with 6.12.9:
fanotify13.c:282: TFAIL: handle_bytes (0) returned in event does not equal to handle_bytes (24) returned in name_to_handle_at(2)

and works with 6.12.10. So far so good.

But when testing on other archs, 6.12.10 fails on aarch64 and ppc64le:

fanotify13.c:339: TFAIL: Did not get an expected event (expected: 200)

That's a different failure than on 6.12.9.

Any hint what could be wrong?

Kind regards,
Petr

> +	}
>  out:
>  	SAFE_CLOSE(fanotify_fd);
>  }