io_uring: clean io_wq_submit_work()'s main loop

Do a bit of cleaning for the main loop of io_wq_submit_work(). Get rid
of switch, just replace it with a single if as we're retrying in both
other cases. Kill issue_sqe label, Get rid of needs_poll nesting and
disambiguate a bit the comment.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/ed12ce0c64e051f9a6b8a37a24f8ea554d299c29.1634987320.git.asml.silence@gmail.com
Reviewed-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 736d456..7f92523 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6749,40 +6749,24 @@ static void io_wq_submit_work(struct io_wq_work *work)
                }
 
                do {
-issue_sqe:
                        ret = io_issue_sqe(req, issue_flags);
+                       if (ret != -EAGAIN)
+                               break;
                        /*
-                        * We can get EAGAIN for polled IO even though we're
+                        * We can get EAGAIN for iopolled IO even though we're
                         * forcing a sync submission from here, since we can't
                         * wait for request slots on the block side.
                         */
-                       if (ret != -EAGAIN)
-                               break;
-                       if (needs_poll) {
-                               bool armed = false;
-
-                               ret = 0;
-                               needs_poll = false;
-                               issue_flags &= ~IO_URING_F_NONBLOCK;
-
-                               switch (io_arm_poll_handler(req)) {
-                               case IO_APOLL_READY:
-                                       goto issue_sqe;
-                               case IO_APOLL_ABORTED:
-                                       /*
-                                        * somehow we failed to arm the poll infra,
-                                        * fallback it to a normal async worker try.
-                                        */
-                                       break;
-                               case IO_APOLL_OK:
-                                       armed = true;
-                                       break;
-                               }
-
-                               if (armed)
-                                       break;
+                       if (!needs_poll) {
+                               cond_resched();
+                               continue;
                        }
-                       cond_resched();
+
+                       if (io_arm_poll_handler(req) == IO_APOLL_OK)
+                               return;
+                       /* aborted or ready, in either case retry blocking */
+                       needs_poll = false;
+                       issue_flags &= ~IO_URING_F_NONBLOCK;
                } while (1);
        }