Commit 3e813c90 authored by Dylan Yudaken's avatar Dylan Yudaken Committed by Jens Axboe
Browse files

io_uring: rework io_uring_enter to simplify return value 



io_uring_enter returns the count submitted preferrably over an error
code. In some code paths this check is not required, so reorganise the
code so that the check is only done as needed.
This is also a prep for returning error codes only in waiting scenarios.

Signed-off-by: default avatarDylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220421091345.2115755-4-dylany@fb.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 08dcd028

fs/io_uring.c

+21 −14
Original line number Diff line number Diff line
@@ -10872,7 +10872,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, 
		size_t, argsz)

{

	struct io_ring_ctx *ctx;

	int submitted = 0;

	struct fd f;

	long ret;
@@ -10935,15 +10934,15 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, 
			if (ret)

				goto out;

		}

		submitted = to_submit;

		ret = to_submit;

	} else if (to_submit) {

		ret = io_uring_add_tctx_node(ctx);

		if (unlikely(ret))

			goto out;



		mutex_lock(&ctx->uring_lock);

		submitted = io_submit_sqes(ctx, to_submit);

		if (submitted != to_submit) {

		ret = io_submit_sqes(ctx, to_submit);

		if (ret != to_submit) {

			mutex_unlock(&ctx->uring_lock);

			goto out;

		}
@@ -10952,6 +10951,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, 
		mutex_unlock(&ctx->uring_lock);

	}

	if (flags & IORING_ENTER_GETEVENTS) {

		int ret2;

		if (ctx->syscall_iopoll) {

			/*

			 * We disallow the app entering submit/complete with
@@ -10961,22 +10961,29 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, 
			 */

			mutex_lock(&ctx->uring_lock);

iopoll_locked:

			ret = io_validate_ext_arg(flags, argp, argsz);

			if (likely(!ret)) {

				min_complete = min(min_complete, ctx->cq_entries);

				ret = io_iopoll_check(ctx, min_complete);

			ret2 = io_validate_ext_arg(flags, argp, argsz);

			if (likely(!ret2)) {

				min_complete = min(min_complete,

						   ctx->cq_entries);

				ret2 = io_iopoll_check(ctx, min_complete);

			}

			mutex_unlock(&ctx->uring_lock);

		} else {

			const sigset_t __user *sig;

			struct __kernel_timespec __user *ts;



			ret = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);

			if (unlikely(ret))

				goto out;

			min_complete = min(min_complete, ctx->cq_entries);

			ret = io_cqring_wait(ctx, min_complete, sig, argsz, ts);

			ret2 = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);

			if (likely(!ret2)) {

				min_complete = min(min_complete,

						   ctx->cq_entries);

				ret2 = io_cqring_wait(ctx, min_complete, sig,

						      argsz, ts);

			}

		}



		if (!ret)

			ret = ret2;



	}



out:
@@ -10984,7 +10991,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, 
out_fput:

	if (!(flags & IORING_ENTER_REGISTERED_RING))

		fdput(f);

	return submitted ? submitted : ret;

	return ret;

}



#ifdef CONFIG_PROC_FS