On 19/02/2021 17:58, Hao Xu wrote:
> When doing __io_uring_register() and waiting for references to exit,
> there could be other threads calling io_uring_enter() and submitting
> sqes which may cause the drain wait endless. So avoid this case by
> checking if ctx->refs is dying.
IMHO, let's leave it as is because it noticeably changes behaviour.
That's nothing that can't be solved in userspace if needed differently.
>
> Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
> ---
> fs/io_uring.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 931671082e61..9aab4d25c2df 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -9356,6 +9356,8 @@ static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz
> }
> submitted = to_submit;
> } else if (to_submit) {
> + if (unlikely(percpu_ref_is_dying(&ctx->refs)))
> + goto out;
> ret = io_uring_add_task_file(ctx, f.file);
> if (unlikely(ret))
> goto out;
>
--
Pavel Begunkov
