io_uring/kbuf: add io_kbuf_commit() helper

Committing the selected ring buffer is currently done in three different
spots, combine it into a helper and just call that.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/kbuf.c

@@ -171,9 +171,8 @@ static void __user *io_ring_buffer_select(struct io_kiocb *req, size_t *len,
 		 * the transfer completes (or if we get -EAGAIN and must poll of
 		 * retry).
 		 */
-		req->flags &= ~REQ_F_BUFFERS_COMMIT;
+		io_kbuf_commit(req, bl, 1);
 		req->buf_list = NULL;
-		bl->head++;
 	}
 	return u64_to_user_ptr(buf->addr);
 }
@@ -297,8 +296,8 @@ int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg,
 		 * committed them, they cannot be put back in the queue.
 		 */
 		if (ret > 0) {
-			req->flags |= REQ_F_BL_NO_RECYCLE;
-			bl->head += ret;
+			req->flags |= REQ_F_BUFFERS_COMMIT | REQ_F_BL_NO_RECYCLE;
+			io_kbuf_commit(req, bl, ret);
 		}
 	} else {
 		ret = io_provided_buffers_select(req, &arg->out_len, bl, arg->iovs);

io_uring/kbuf.h

@@ -121,15 +121,21 @@ static inline bool io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
 	return false;
 }
 
+static inline void io_kbuf_commit(struct io_kiocb *req,
+				  struct io_buffer_list *bl, int nr)
+{
+	if (unlikely(!(req->flags & REQ_F_BUFFERS_COMMIT)))
+		return;
+	bl->head += nr;
+	req->flags &= ~REQ_F_BUFFERS_COMMIT;
+}
+
 static inline void __io_put_kbuf_ring(struct io_kiocb *req, int nr)
 {
 	struct io_buffer_list *bl = req->buf_list;
 
 	if (bl) {
-		if (req->flags & REQ_F_BUFFERS_COMMIT) {
-			bl->head += nr;
-			req->flags &= ~REQ_F_BUFFERS_COMMIT;
-		}
+		io_kbuf_commit(req, bl, nr);
 		req->buf_index = bl->bgid;
 	}
 	req->flags &= ~REQ_F_BUFFER_RING;