Commit cce4b8b0 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: don't fail overflow on in_idle 



As CQE overflows are now untied from requests and so don't hold any
ref, we don't need to handle exiting/exec'ing cases there anymore.
Moreover, it's much nicer in regards to userspace to save overflowed
CQEs whenever possible, so remove failing on in_idle.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/d873b7dab75c7f3039ead9628a745bea01f2cfd2.1618278933.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e31001a3

fs/io_uring.c

+20 −24
Original line number Diff line number Diff line
@@ -1513,13 +1513,18 @@ static bool io_cqring_event_overflow(struct io_kiocb *req, long res, 
				     unsigned int cflags)

{

	struct io_ring_ctx *ctx = req->ctx;



	if (!atomic_read(&req->task->io_uring->in_idle)) {

	struct io_overflow_cqe *ocqe;



	ocqe = kmalloc(sizeof(*ocqe), GFP_ATOMIC | __GFP_ACCOUNT);

		if (!ocqe)

			goto overflow;

	if (!ocqe) {

		/*

		 * If we're in ring overflow flush mode, or in task cancel mode,

		 * or cannot allocate an overflow entry, then we need to drop it

		 * on the floor.

		 */

		WRITE_ONCE(ctx->rings->cq_overflow, ++ctx->cached_cq_overflow);

		return false;

	}

	if (list_empty(&ctx->cq_overflow_list)) {

		set_bit(0, &ctx->sq_check_overflow);

		set_bit(0, &ctx->cq_check_overflow);
@@ -1531,15 +1536,6 @@ static bool io_cqring_event_overflow(struct io_kiocb *req, long res, 
	list_add_tail(&ocqe->list, &ctx->cq_overflow_list);

	return true;

}

overflow:

	/*

	 * If we're in ring overflow flush mode, or in task cancel mode,

	 * or cannot allocate an overflow entry, then we need to drop it

	 * on the floor.

	 */

	WRITE_ONCE(ctx->rings->cq_overflow, ++ctx->cached_cq_overflow);

	return false;

}



static inline bool __io_cqring_fill_event(struct io_kiocb *req, long res,

					     unsigned int cflags)