Commit 22b2ca31 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: extra a helper for drain init 



Add a helper io_init_req_drain for initialising requests with
IOSQE_DRAIN set. Also move bits from preambule of io_drain_req() in
there, because we already modify all the bits needed inside the helper.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/dcb412825b35b1cb8891245a387d7d69f8d14cef.1633107393.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5e371265

fs/io_uring.c

+22 −26
Original line number Diff line number Diff line
@@ -6430,28 +6430,11 @@ static u32 io_get_sequence(struct io_kiocb *req) 


static bool io_drain_req(struct io_kiocb *req)

{

	struct io_kiocb *pos;

	struct io_ring_ctx *ctx = req->ctx;

	struct io_defer_entry *de;

	int ret;

	u32 seq;



	/* not interested in head, start from the first linked */

	io_for_each_link(pos, req->link) {

		/*

		 * If we need to drain a request in the middle of a link, drain

		 * the head request and the next request/link after the current

		 * link. Considering sequential execution of links,

		 * IOSQE_IO_DRAIN will be maintained for every request of our

		 * link.

		 */

		if (pos->flags & REQ_F_IO_DRAIN) {

			ctx->drain_next = true;

			req->flags |= REQ_F_IO_DRAIN;

			break;

		}

	}



	/* Still need defer if there is pending req in defer list. */

	if (likely(list_empty_careful(&ctx->defer_list) &&

		!(req->flags & REQ_F_IO_DRAIN))) {
@@ -6992,6 +6975,25 @@ static inline bool io_check_restriction(struct io_ring_ctx *ctx, 
	return true;

}



static void io_init_req_drain(struct io_kiocb *req)

{

	struct io_ring_ctx *ctx = req->ctx;

	struct io_kiocb *head = ctx->submit_state.link.head;



	ctx->drain_active = true;

	if (head) {

		/*

		 * If we need to drain a request in the middle of a link, drain

		 * the head request and the next request/link after the current

		 * link. Considering sequential execution of links,

		 * IOSQE_IO_DRAIN will be maintained for every request of our

		 * link.

		 */

		head->flags |= IOSQE_IO_DRAIN | REQ_F_FORCE_ASYNC;

		ctx->drain_next = true;

	}

}



static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,

		       const struct io_uring_sqe *sqe)

	__must_hold(&ctx->uring_lock)
@@ -7018,14 +7020,8 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, 
		if ((sqe_flags & IOSQE_BUFFER_SELECT) &&

		    !io_op_defs[req->opcode].buffer_select)

			return -EOPNOTSUPP;

		if (sqe_flags & IOSQE_IO_DRAIN) {

			struct io_submit_link *link = &ctx->submit_state.link;



			ctx->drain_active = true;

			req->flags |= REQ_F_FORCE_ASYNC;

			if (link->head)

				link->head->flags |= IOSQE_IO_DRAIN | REQ_F_FORCE_ASYNC;

		}

		if (sqe_flags & IOSQE_IO_DRAIN)

			io_init_req_drain(req);

	}

	if (unlikely(ctx->restricted || ctx->drain_active || ctx->drain_next)) {

		if (ctx->restricted && !io_check_restriction(ctx, req, sqe_flags))
@@ -7037,7 +7033,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, 
		if (unlikely(ctx->drain_next) && !ctx->submit_state.link.head) {

			ctx->drain_next = false;

			ctx->drain_active = true;

			req->flags |= REQ_F_FORCE_ASYNC | IOSQE_IO_DRAIN;

			req->flags |= IOSQE_IO_DRAIN | REQ_F_FORCE_ASYNC;

		}

	}