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

[Petr Vorel]

Hi Amir, all,
> 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.

Also fanotify13.c for the same reason on s390x on various SLES (enterprise)
kernels based on various mainline kernels (6.4, 5.3.18, ...).

fanotify13.c:341: TFAIL: Did not get an expected event (expected: 3403000018)

(Just a different mask than on aarch64 and ppc64le.)

@Cyril: due the above I suggest to merge before release only fanotify05.c and
fanotify21.c changes.

Kind regards,
Petr

> Any hint what could be wrong?

> Kind regards,
> Petr

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