io_uring: io_queue_link*() right after submit

After a call to io_submit_sqe(), it's already known whether it needs
to queue a link or not. Do it there, as it's simplier and doesn't keep
an extra variable across the loop.

Reviewed-by：Bob Liu <bob.liu@oracle.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 375c09a43d32211856b5f45bd695887ef4242d5f..6524898831e05cf163ef8d620716c42a3b806b8b 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2700,7 +2700,6 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
        struct io_submit_state state, *statep = NULL;
        struct io_kiocb *link = NULL;
        struct io_kiocb *shadow_req = NULL;
-       bool prev_was_link = false;
        int i, submitted = 0;
        bool mm_fault = false;
 
@@ -2723,17 +2722,6 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
                        }
                }
 
-               /*
-                * If previous wasn't linked and we have a linked command,
-                * that's the end of the chain. Submit the previous link.
-                */
-               if (!prev_was_link && link) {
-                       io_queue_link_head(ctx, link, &link->submit, shadow_req);
-                       link = NULL;
-                       shadow_req = NULL;
-               }
-               prev_was_link = (s.sqe->flags & IOSQE_IO_LINK) != 0;
-
                if (link && (s.sqe->flags & IOSQE_IO_DRAIN)) {
                        if (!shadow_req) {
                                shadow_req = io_get_req(ctx, NULL);
@@ -2754,6 +2742,16 @@ out:
                trace_io_uring_submit_sqe(ctx, s.sqe->user_data, true, async);
                io_submit_sqe(ctx, &s, statep, &link);
                submitted++;
+
+               /*
+                * If previous wasn't linked and we have a linked command,
+                * that's the end of the chain. Submit the previous link.
+                */
+               if (!(s.sqe->flags & IOSQE_IO_LINK) && link) {
+                       io_queue_link_head(ctx, link, &link->submit, shadow_req);
+                       link = NULL;
+                       shadow_req = NULL;
+               }
        }
 
        if (link)