Re: [PATCH 2/7] io_uring: handle signals for IO threads like a normal thread

Eric W. Biederman
2021-03-27T17:42:34Z

Jens Axboe <axboe@kernel.dk> writes:

> On 3/26/21 4:38 PM, Jens Axboe wrote:
>> OK good point, and follows the same logic even if it won't make a
>> difference in my case. I'll make the change.
>
> Made the suggested edits and ran the quick tests and the KILL/STOP
> testing, and no ill effects observed. Kicked off the longer runs now.
>
> Not a huge amount of changes from the posted series, but please peruse
> here if you want to double check:
>
> https://git.kernel.dk/cgit/linux-block/log/?h=io_uring-5.12
>
> And diff against v2 posted is below. Thanks!

That looks good. Thanks.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>

>
> diff --git a/fs/io-wq.c b/fs/io-wq.c
> index 3e2f059a1737..7434eb40ca8c 100644
> --- a/fs/io-wq.c
> +++ b/fs/io-wq.c
> @@ -505,10 +505,9 @@ static int io_wqe_worker(void *data)
> if (signal_pending(current)) {
> struct ksignal ksig;
>
> - if (fatal_signal_pending(current))
> - break;
> - if (get_signal(&ksig))
> + if (!get_signal(&ksig))
> continue;
> + break;
> }
> if (ret)
> continue;
> @@ -722,10 +721,9 @@ static int io_wq_manager(void *data)
> if (signal_pending(current)) {
> struct ksignal ksig;
>
> - if (fatal_signal_pending(current))
> - set_bit(IO_WQ_BIT_EXIT, &wq->state);
> - else if (get_signal(&ksig))
> + if (!get_signal(&ksig))
> continue;
> + set_bit(IO_WQ_BIT_EXIT, &wq->state);
> }
> } while (!test_bit(IO_WQ_BIT_EXIT, &wq->state));
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 66ae46874d85..880abd8b6d31 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -6746,10 +6746,9 @@ static int io_sq_thread(void *data)
> if (signal_pending(current)) {
> struct ksignal ksig;
>
> - if (fatal_signal_pending(current))
> - break;
> - if (get_signal(&ksig))
> + if (!get_signal(&ksig))
> continue;
> + break;
> }
> sqt_spin = false;
> cap_entries = !list_is_singular(&sqd->ctx_list);
> diff --git a/kernel/signal.c b/kernel/signal.c
> index 5b75fbe3d2d6..f2718350bf4b 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -2752,15 +2752,6 @@ bool get_signal(struct ksignal *ksig)
> */
> current->flags |= PF_SIGNALED;
>
> - /*
> - * PF_IO_WORKER threads will catch and exit on fatal signals
> - * themselves. They have cleanup that must be performed, so
> - * we cannot call do_exit() on their behalf. coredumps also
> - * do not apply to them.
> - */
> - if (current->flags & PF_IO_WORKER)
> - return false;
> -
> if (sig_kernel_coredump(signr)) {
> if (print_fatal_signals)
> print_fatal_signal(ksig->info.si_signo);
> @@ -2776,6 +2767,14 @@ bool get_signal(struct ksignal *ksig)
> do_coredump(&ksig->info);
> }
>
> + /*
> + * PF_IO_WORKER threads will catch and exit on fatal signals
> + * themselves. They have cleanup that must be performed, so
> + * we cannot call do_exit() on their behalf.
> + */
> + if (current->flags & PF_IO_WORKER)
> + goto out;
> +
> /*
> * Death signals, no core dump.
> */
> @@ -2783,7 +2782,7 @@ bool get_signal(struct ksignal *ksig)
> /* NOTREACHED */
> }
> spin_unlock_irq(&sighand->siglock);
> -
> +out:
> ksig->sig = signr;
>
> if (!(ksig->ka.sa.sa_flags & SA_EXPOSE_TAGBITS))