[LTP] [PATCH] fanotify21: fix test failure when running iterations

[Jan Kara]

On Thu 28-05-26 17:19:38, Amir Goldstein wrote:
> Peter reported that fanotify21 -i2 fails.
> Fix this by always remounting ro/rw before every test.
> Use a bind mount, where remount works regardless of base fs.
> 
> Reported-by: pvorel@suse.cz
> Link: https://lore.kernel.org/linux-fsdevel/20260527072312.GA231966@pevik/
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Ah, nice trick. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
> 
> Petr,
> 
> This is a simplified version of AnonymeMeow's patch.
> 
> Thanks,
> Amir.
> 
>  .../kernel/syscalls/fanotify/fanotify21.c      | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify21.c b/testcases/kernel/syscalls/fanotify/fanotify21.c
> index c95895c93..fd18d7e29 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify21.c
> +++ b/testcases/kernel/syscalls/fanotify/fanotify21.c
> @@ -123,6 +123,9 @@ static void do_setup(void)
>  	int pidfd;
>  	int init_flags = FAN_REPORT_PIDFD;
>  
> +	/* Bind mount so remount ro/rw always work */
> +	SAFE_MOUNT(MOUNT_PATH, MOUNT_PATH, "none", MS_BIND, NULL);
> +
>  	if (tst_variant) {
>  		fanotify_fd = -1;
>  		fd_error_unsupported = fanotify_init_flags_supported_on_fs(FAN_REPORT_FD_ERROR, ".");
> @@ -171,15 +174,9 @@ static void do_test(unsigned int num)
>  		return;
>  	}
>  
> -	if (tc->remount_ro) {
> -		/* SAFE_MOUNT fails to remount FUSE */
> -		if (mount(tst_device->dev, MOUNT_PATH, tst_device->fs_type,
> -			  MS_REMOUNT|MS_RDONLY, NULL) != 0) {
> -			tst_brk(TFAIL,
> -				"filesystem %s failed to remount readonly",
> -				tst_device->fs_type);
> -		}
> -	}
> +	/* remount ro/rw the bind mount */
> +	SAFE_MOUNT("none", MOUNT_PATH, "none", MS_BIND | MS_REMOUNT |
> +		   (tc->remount_ro ? MS_RDONLY : 0), NULL);
>  
>  	/*
>  	 * Generate the event in either self or a child process. Event
> @@ -355,6 +352,9 @@ static void do_cleanup(void)
>  
>  	if (self_pidfd_fdinfo)
>  		free(self_pidfd_fdinfo);
> +
> +	/* Unmount the bind mount */
> +	SAFE_UMOUNT(MOUNT_PATH);
>  }
>  
>  static struct tst_test test = {
> -- 
> 2.54.0
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR