On Tue, Jun 27, 2023 at 2:09 AM Ahelenia Ziemiańska
<nabijaczleweli@xxxxxxxxxxxxxxxxxx> wrote:
>
> Same logic applies here: this can fill up the pipe and pollers that rely
> on getting IN_MODIFY notifications never wake up.
>
> Fixes: 983652c69199 ("splice: report related fsnotify events")
> Link: https://lore.kernel.org/linux-fsdevel/jbyihkyk5dtaohdwjyivambb2gffyjs3dodpofafnkkunxq7bu@jngkdxx65pux/t/#u
> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@xxxxxxxxxxxxxxxxxx>
> ---
> fs/splice.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/splice.c b/fs/splice.c
> index 94fae24f9d54..a18274209dc1 100644
> --- a/fs/splice.c
> +++ b/fs/splice.c
> @@ -1447,6 +1447,9 @@ SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, uiov,
> else
> error = vmsplice_to_user(f.file, &iter, flags);
>
> + if (error > 0)
> + fsnotify_modify(f.file);
> +
Wow, that is a twisted syscall, it does either write or read on the pipe
depending on whether it was open for read or write.
so you need to move fsnotify_modify() into vmsplice_to_pipe() and
add fsnotify_access() to vmsplice_to_user().
Thanks,
Amir.
