io_uring: refactor req allocation

Follow the io_get_sqe pattern returning the result via a pointer
and hide request cache refill inside io_alloc_req().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8c37c2e8a3cb5e4cd6a8ae3b91371227a92708a6.1674484266.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 11 insertions, 8 deletions

diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 9270156288aa..f90816aac896 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -341,16 +341,9 @@ static inline bool io_req_cache_empty(struct io_ring_ctx *ctx)
 	return !ctx->submit_state.free_list.next;
 }
 
-static inline bool io_alloc_req_refill(struct io_ring_ctx *ctx)
-{
-	if (unlikely(io_req_cache_empty(ctx)))
-		return __io_alloc_req_refill(ctx);
-	return true;
-}
-
 extern struct kmem_cache *req_cachep;
 
-static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
+static inline struct io_kiocb *io_extract_req(struct io_ring_ctx *ctx)
 {
 	struct io_kiocb *req;
 
@@ -360,6 +353,16 @@ static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
 	return req;
 }
 
+static inline bool io_alloc_req(struct io_ring_ctx *ctx, struct io_kiocb **req)
+{
+	if (unlikely(io_req_cache_empty(ctx))) {
+		if (!__io_alloc_req_refill(ctx))
+			return false;
+	}
+	*req = io_extract_req(ctx);
+	return true;
+}
+
 static inline bool io_allowed_defer_tw_run(struct io_ring_ctx *ctx)
 {
 	return likely(ctx->submitter_task == current);