Commit 864ea921 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: refactor io_alloc_req 



Replace the main if of io_flush_cached_reqs() with inverted condition +
goto, so all the cases are handled in the same way. And also extract
io_preinit_req() to make it cleaner and easier to refer to.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1abcba1f7b55dc53bf1dbe95036e345ffb1d5b01.1628471125.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8724dd8c

fs/io_uring.c

+33 −33
Original line number Diff line number Diff line
@@ -1702,6 +1702,19 @@ static void io_req_complete_failed(struct io_kiocb *req, long res) 
	io_req_complete_post(req, res, 0);

}



/*

 * Don't initialise the fields below on every allocation, but do that in

 * advance and keep them valid across allocations.

 */

static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)

{

	req->ctx = ctx;

	req->link = NULL;

	req->async_data = NULL;

	/* not necessary, but safer to zero */

	req->result = 0;

}



static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,

					struct io_comp_state *cs)

{
@@ -1744,14 +1757,12 @@ static bool io_flush_cached_reqs(struct io_ring_ctx *ctx) 
static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)

{

	struct io_submit_state *state = &ctx->submit_state;



	BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH);



	if (!state->free_reqs) {

	gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;

	int ret, i;



		if (io_flush_cached_reqs(ctx))

	BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH);



	if (likely(state->free_reqs || io_flush_cached_reqs(ctx)))

		goto got_req;



	ret = kmem_cache_alloc_bulk(req_cachep, gfp, IO_REQ_ALLOC_BATCH,
@@ -1768,21 +1779,9 @@ static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx) 
		ret = 1;

	}



		/*

		 * Don't initialise the fields below on every allocation, but

		 * do that in advance and keep valid on free.

		 */

		for (i = 0; i < ret; i++) {

			struct io_kiocb *req = state->reqs[i];



			req->ctx = ctx;

			req->link = NULL;

			req->async_data = NULL;

			/* not necessary, but safer to zero */

			req->result = 0;

		}

	for (i = 0; i < ret; i++)

		io_preinit_req(state->reqs[i], ctx);

	state->free_reqs = ret;

	}

got_req:

	state->free_reqs--;

	return state->reqs[state->free_reqs];
@@ -6569,6 +6568,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, 
	unsigned int sqe_flags;

	int personality, ret = 0;



	/* req is partially pre-initialised, see io_preinit_req() */

	req->opcode = READ_ONCE(sqe->opcode);

	/* same numerical values with corresponding REQ_F_*, safe to copy */

	req->flags = sqe_flags = READ_ONCE(sqe->flags);