Commit 8c130827 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: don't alter iopoll reissue fail ret code 



When reissue_prep failed in io_complete_rw_iopoll(), we change return
code to -EIO to prevent io_iopoll_complete() from doing resubmission.
Mark requests with a new flag (i.e. REQ_F_DONT_REISSUE) instead and
retain the original return value.

It also removes io_rw_reissue() from io_iopoll_complete() that will be
used later.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1c98679d

fs/io_uring.c

+16 −25
Original line number Diff line number Diff line
@@ -696,6 +696,7 @@ enum { 
	REQ_F_LTIMEOUT_ACTIVE_BIT,

	REQ_F_COMPLETE_INLINE_BIT,

	REQ_F_REISSUE_BIT,

	REQ_F_DONT_REISSUE_BIT,

	/* keep async read/write and isreg together and in order */

	REQ_F_ASYNC_READ_BIT,

	REQ_F_ASYNC_WRITE_BIT,
@@ -741,6 +742,8 @@ enum { 
	REQ_F_COMPLETE_INLINE	= BIT(REQ_F_COMPLETE_INLINE_BIT),

	/* caller should reissue async */

	REQ_F_REISSUE		= BIT(REQ_F_REISSUE_BIT),

	/* don't attempt request reissue, see io_rw_reissue() */

	REQ_F_DONT_REISSUE	= BIT(REQ_F_DONT_REISSUE_BIT),

	/* supports async reads */

	REQ_F_ASYNC_READ	= BIT(REQ_F_ASYNC_READ_BIT),

	/* supports async writes */
@@ -1016,7 +1019,6 @@ static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node( 
			struct io_ring_ctx *ctx);

static void io_ring_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);



static bool io_rw_reissue(struct io_kiocb *req);

static void io_cqring_fill_event(struct io_kiocb *req, long res);

static void io_put_req(struct io_kiocb *req);

static void io_put_req_deferred(struct io_kiocb *req, int nr);
@@ -2253,9 +2255,11 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, 
		req = list_first_entry(done, struct io_kiocb, inflight_entry);

		list_del(&req->inflight_entry);



		if (READ_ONCE(req->result) == -EAGAIN) {

		if (READ_ONCE(req->result) == -EAGAIN &&

		    !(req->flags & REQ_F_DONT_REISSUE)) {

			req->iopoll_completed = 0;

			if (io_rw_reissue(req))

			req_ref_get(req);

			io_queue_async_work(req);

			continue;

		}
@@ -2471,24 +2475,6 @@ static bool io_rw_should_reissue(struct io_kiocb *req) 
}

#endif



static bool io_rw_reissue(struct io_kiocb *req)

{

#ifdef CONFIG_BLOCK

	if (!io_rw_should_reissue(req))

		return false;



	lockdep_assert_held(&req->ctx->uring_lock);



	if (io_resubmit_prep(req)) {

		req_ref_get(req);

		io_queue_async_work(req);

		return true;

	}

	req_set_fail_links(req);

#endif

	return false;

}



static void __io_complete_rw(struct io_kiocb *req, long res, long res2,

			     unsigned int issue_flags)

{
@@ -2527,15 +2513,17 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) 
			iov_iter_revert(&rw->iter,

					req->result - iov_iter_count(&rw->iter));

		else if (!io_resubmit_prep(req))

			res = -EIO;

			req->flags |= REQ_F_DONT_REISSUE;

	}

#endif



	if (kiocb->ki_flags & IOCB_WRITE)

		kiocb_end_write(req);



	if (res != -EAGAIN && res != req->result)

	if (res != -EAGAIN && res != req->result) {

		req->flags |= REQ_F_DONT_REISSUE;

		req_set_fail_links(req);

	}



	WRITE_ONCE(req->result, res);

	/* order with io_iopoll_complete() checking ->result */
@@ -2776,7 +2764,10 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret, 


	if (check_reissue && req->flags & REQ_F_REISSUE) {

		req->flags &= ~REQ_F_REISSUE;

		if (!io_rw_reissue(req)) {

		if (!io_resubmit_prep(req)) {

			req_ref_get(req);

			io_queue_async_work(req);

		} else {

			int cflags = 0;



			req_set_fail_links(req);