epoll: pull all code between fetch_events and send_event into the loop

This is a no-op change which simplifies the follow up patches.

Link: https://lkml.kernel.org/r/20201106231635.3528496-7-soheil.kdev@gmail.com
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Khazhismel Kumykov <khazhy@google.com>
Cc: Guantao Liu <guantaol@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 03d0ac076a169025d6a8acff67d6dcc4a95ae921..63a7a6e13dfcd02507682537d30159ece6483aaf 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1774,14 +1774,14 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
        }
 
 fetch_events:
-       eavail = ep_events_available(ep);
-       if (!eavail)
-               eavail = ep_busy_loop(ep, timed_out);
+       do {
+               eavail = ep_events_available(ep);
+               if (!eavail)
+                       eavail = ep_busy_loop(ep, timed_out);
 
-       if (eavail)
-               goto send_events;
+               if (eavail)
+                       goto send_events;
 
-       do {
                if (signal_pending(current))
                        return -EINTR;
 
@@ -1830,21 +1830,22 @@ fetch_events:
                 * carefully under lock, below.
                 */
                eavail = 1;
-       } while (0);
 
-       if (!list_empty_careful(&wait.entry)) {
-               write_lock_irq(&ep->lock);
-               /*
-                * If the thread timed out and is not on the wait queue, it
-                * means that the thread was woken up after its timeout expired
-                * before it could reacquire the lock. Thus, when wait.entry is
-                * empty, it needs to harvest events.
-                */
-               if (timed_out)
-                       eavail = list_empty(&wait.entry);
-               __remove_wait_queue(&ep->wq, &wait);
-               write_unlock_irq(&ep->lock);
-       }
+               if (!list_empty_careful(&wait.entry)) {
+                       write_lock_irq(&ep->lock);
+                       /*
+                        * If the thread timed out and is not on the wait queue,
+                        * it means that the thread was woken up after its
+                        * timeout expired before it could reacquire the lock.
+                        * Thus, when wait.entry is empty, it needs to harvest
+                        * events.
+                        */
+                       if (timed_out)
+                               eavail = list_empty(&wait.entry);
+                       __remove_wait_queue(&ep->wq, &wait);
+                       write_unlock_irq(&ep->lock);
+               }
+       } while (0);
 
 send_events:
        /*