epoll: replace gotos with a proper loop
The existing loop is pointless, and the labels make it really hard to
follow the structure.
Replace that control structure with a simple loop that returns when there
are new events, there is a signal, or the thread has timed out.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Soheil Hassas Yeganeh <[email protected]>
Suggested-by: Linus Torvalds <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Reviewed-by: Khazhismel Kumykov <[email protected]>
Cc: Guantao Liu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 63a7a6e..1e0030c 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1743,7 +1743,7 @@ static inline struct timespec64 ep_set_mstimeout(long ms)
static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
int maxevents, long timeout)
{
- int res, eavail, timed_out = 0;
+ int res, eavail = 0, timed_out = 0;
u64 slack = 0;
wait_queue_entry_t wait;
ktime_t expires, *to = NULL;
@@ -1769,18 +1769,30 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
write_lock_irq(&ep->lock);
eavail = ep_events_available(ep);
write_unlock_irq(&ep->lock);
-
- goto send_events;
}
-fetch_events:
- do {
- eavail = ep_events_available(ep);
- if (!eavail)
- eavail = ep_busy_loop(ep, timed_out);
+ while (1) {
+ if (eavail) {
+ /*
+ * Try to transfer events to user space. In case we get
+ * 0 events and there's still timeout left over, we go
+ * trying again in search of more luck.
+ */
+ res = ep_send_events(ep, events, maxevents);
+ if (res)
+ return res;
+ }
+ if (timed_out)
+ return 0;
+
+ eavail = ep_events_available(ep);
if (eavail)
- goto send_events;
+ continue;
+
+ eavail = ep_busy_loop(ep, timed_out);
+ if (eavail)
+ continue;
if (signal_pending(current))
return -EINTR;
@@ -1845,19 +1857,7 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
__remove_wait_queue(&ep->wq, &wait);
write_unlock_irq(&ep->lock);
}
- } while (0);
-
-send_events:
- /*
- * Try to transfer events to user space. In case we get 0 events and
- * there's still timeout left over, we go trying again in search of
- * more luck.
- */
- if (eavail &&
- !(res = ep_send_events(ep, events, maxevents)) && !timed_out)
- goto fetch_events;
-
- return res;
+ }
}
/**
