Commit e54945ae authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: SQPOLL stop error handling fixes 



If we fail to fork an SQPOLL worker, we can hit cancel, and hence
attempted thread stop, with the thread already being stopped. Ensure
we check for that.

Also guard thread stop fully by the sqd mutex, just like we do for
park.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 470ec4ed

fs/io_uring.c

+18 −7
Original line number Diff line number Diff line
@@ -6793,9 +6793,9 @@ static int io_sq_thread(void *data) 
		ctx->sqo_exec = 1;

		io_ring_set_wakeup_flag(ctx);

	}

	mutex_unlock(&sqd->lock);



	complete(&sqd->exited);

	mutex_unlock(&sqd->lock);

	do_exit(0);

}
@@ -7118,13 +7118,19 @@ static bool io_sq_thread_park(struct io_sq_data *sqd) 


static void io_sq_thread_stop(struct io_sq_data *sqd)

{

	if (!sqd->thread)

	if (test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state))

		return;



	mutex_lock(&sqd->lock);

	if (sqd->thread) {

		set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state);

		WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state));

		wake_up_process(sqd->thread);

		mutex_unlock(&sqd->lock);

		wait_for_completion(&sqd->exited);

		WARN_ON_ONCE(sqd->thread);

	} else {

		mutex_unlock(&sqd->lock);

	}

}



static void io_put_sq_data(struct io_sq_data *sqd)
@@ -8867,6 +8873,11 @@ static void io_uring_cancel_sqpoll(struct io_ring_ctx *ctx) 
	if (!io_sq_thread_park(sqd))

		return;

	tctx = ctx->sq_data->thread->io_uring;

	/* can happen on fork/alloc failure, just ignore that state */

	if (!tctx) {

		io_sq_thread_unpark(sqd);

		return;

	}



	atomic_inc(&tctx->in_idle);

	do {