[RFC PATCH 17/27] ep_send_events_proc(): fold into the caller

Al Viro
2020-10-04T02:39:50Z

... and get rid of struct ep_send_events_data - not needed anymore.
The weird way of passing the arguments in (and real return value
out - nominal return value of ep_send_events_proc() is ignored)
was due to the signature forced on ep_scan_ready_list() callbacks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/eventpoll.c | 60 ++++++++++++++++++++--------------------------------------
1 file changed, 20 insertions(+), 40 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 3b3a862f8014..ac996b959e94 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -233,13 +233,6 @@ struct ep_pqueue {
struct epitem *epi;
};

-/* Used by the ep_send_events() function as callback private data */
-struct ep_send_events_data {
- int maxevents;
- struct epoll_event __user *events;
- int res;
-};
-
/*
* Configuration options available inside /proc/sys/fs/epoll/
*/
@@ -1570,18 +1563,17 @@ static int ep_modify(struct eventpoll *ep, struct epitem *epi,
return 0;
}

-static __poll_t ep_send_events_proc(struct eventpoll *ep, struct list_head *head,
- void *priv)
+static int ep_send_events(struct eventpoll *ep,
+ struct epoll_event __user *events, int maxevents)
{
- struct ep_send_events_data *esed = priv;
- __poll_t revents;
struct epitem *epi, *tmp;
- struct epoll_event __user *uevent = esed->events;
- struct wakeup_source *ws;
+ LIST_HEAD(txlist);
poll_table pt;
+ int res = 0;

init_poll_funcptr(&pt, NULL);
- esed->res = 0;
+
+ ep_start_scan(ep, 0, false, &txlist);

/*
* We can loop without lock because we are passed a task private list.
@@ -1590,8 +1582,11 @@ static __poll_t ep_send_events_proc(struct eventpoll *ep, struct list_head *head
*/
lockdep_assert_held(&ep->mtx);

- list_for_each_entry_safe(epi, tmp, head, rdllink) {
- if (esed->res >= esed->maxevents)
+ list_for_each_entry_safe(epi, tmp, &txlist, rdllink) {
+ struct wakeup_source *ws;
+ __poll_t revents;
+
+ if (res >= maxevents)
break;

/*
@@ -1622,16 +1617,16 @@ static __poll_t ep_send_events_proc(struct eventpoll *ep, struct list_head *head
if (!revents)
continue;

- if (__put_user(revents, &uevent->events) ||
- __put_user(epi->event.data, &uevent->data)) {
- list_add(&epi->rdllink, head);
+ if (__put_user(revents, &events->events) ||
+ __put_user(epi->event.data, &events->data)) {
+ list_add(&epi->rdllink, &txlist);
ep_pm_stay_awake(epi);
- if (!esed->res)
- esed->res = -EFAULT;
- return 0;
+ if (!res)
+ res = -EFAULT;
+ break;
}
- esed->res++;
- uevent++;
+ res++;
+ events++;
if (epi->event.events & EPOLLONESHOT)
epi->event.events &= EP_PRIVATE_BITS;
else if (!(epi->event.events & EPOLLET)) {
@@ -1650,24 +1645,9 @@ static __poll_t ep_send_events_proc(struct eventpoll *ep, struct list_head *head
ep_pm_stay_awake(epi);
}
}
-
- return 0;
-}
-
-static int ep_send_events(struct eventpoll *ep,
- struct epoll_event __user *events, int maxevents)
-{
- struct ep_send_events_data esed;
- LIST_HEAD(txlist);
-
- esed.maxevents = maxevents;
- esed.events = events;
-
- ep_start_scan(ep, 0, false, &txlist);
- ep_send_events_proc(ep, &txlist, &esed);
ep_done_scan(ep, 0, false, &txlist);

- return esed.res;
+ return res;
}

static inline struct timespec64 ep_set_mstimeout(long ms)
--
2.11.0