Commit bcbb7bf6 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: allow submissions to continue on error 



By default, io_uring will stop submitting a batch of requests if we run
into an error submitting a request. This isn't strictly necessary, as
the error result is passed out-of-band via a CQE anyway. And it can be
a bit confusing for some applications.

Provide a way to setup a ring that will continue submitting on error,
when the error CQE has been posted.

There's still one case that will break out of submission. If we fail
allocating a request, then we'll still return -ENOMEM. We could in theory
post a CQE for that condition too even if we never got a request. Leave
that for a potential followup.

Reported-by: default avatarDylan Yudaken <dylany@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b1c62645

fs/io_uring.c

+9 −3
Original line number Diff line number Diff line
@@ -7801,8 +7801,14 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) 
		}

		/* will complete beyond this point, count as submitted */

		submitted++;

		if (io_submit_sqe(ctx, req, sqe))

		if (io_submit_sqe(ctx, req, sqe)) {

			/*

			 * Continue submitting even for sqe failure if the

			 * ring was setup with IORING_SETUP_SUBMIT_ALL

			 */

			if (!(ctx->flags & IORING_SETUP_SUBMIT_ALL))

				break;

		}

	} while (submitted < nr);



	if (unlikely(submitted != nr)) {
@@ -11265,7 +11271,7 @@ static long io_uring_setup(u32 entries, struct io_uring_params __user *params) 
	if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |

			IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |

			IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |

			IORING_SETUP_R_DISABLED))

			IORING_SETUP_R_DISABLED | IORING_SETUP_SUBMIT_ALL))

		return -EINVAL;



	return  io_uring_create(entries, &p, params);

include/uapi/linux/io_uring.h

+1 −0
Original line number Diff line number Diff line
@@ -101,6 +101,7 @@ enum { 
#define IORING_SETUP_CLAMP	(1U << 4)	/* clamp SQ/CQ ring sizes */

#define IORING_SETUP_ATTACH_WQ	(1U << 5)	/* attach to existing wq */

#define IORING_SETUP_R_DISABLED	(1U << 6)	/* start with ring disabled */

#define IORING_SETUP_SUBMIT_ALL	(1U << 7)	/* continue submit on error */



enum {

	IORING_OP_NOP,