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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Marc Zyngier <maz@kernel.org>
Subject: [RFC PATCH 17/27] ep_send_events_proc(): fold into the caller
Date: Sun,  4 Oct 2020 03:39:19 +0100	[thread overview]
Message-ID: <20201004023929.2740074-17-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20201004023929.2740074-1-viro@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

... 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


  parent reply	other threads:[~2020-10-04  2:39 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-04  2:36 [RFC][PATCHSET] epoll cleanups Al Viro
2020-10-04  2:39 ` [RFC PATCH 01/27] epoll: switch epitem->pwqlist to single-linked list Al Viro
2020-10-04  2:39   ` [RFC PATCH 02/27] epoll: get rid of epitem->nwait Al Viro
2020-10-04  2:39   ` [RFC PATCH 03/27] untangling ep_call_nested(): get rid of useless arguments Al Viro
2020-10-04  2:39   ` [RFC PATCH 04/27] untangling ep_call_nested(): it's all serialized on epmutex Al Viro
2020-10-04  2:39   ` [RFC PATCH 05/27] untangling ep_call_nested(): take pushing cookie into a helper Al Viro
2020-10-04  2:39   ` [RFC PATCH 06/27] untangling ep_call_nested(): move push/pop of cookie into the callbacks Al Viro
2020-10-04  2:39   ` [RFC PATCH 07/27] untangling ep_call_nested(): and there was much rejoicing Al Viro
2020-10-04  2:39   ` [RFC PATCH 08/27] reverse_path_check_proc(): sane arguments Al Viro
2020-10-04  2:39   ` [RFC PATCH 09/27] reverse_path_check_proc(): don't bother with cookies Al Viro
2020-10-04  2:39   ` [RFC PATCH 10/27] clean reverse_path_check_proc() a bit Al Viro
2020-10-04  2:39   ` [RFC PATCH 11/27] ep_loop_check_proc(): lift pushing the cookie into callers Al Viro
2020-10-04  2:39   ` [RFC PATCH 12/27] get rid of ep_push_nested() Al Viro
2020-10-04  2:39   ` [RFC PATCH 13/27] ep_loop_check_proc(): saner calling conventions Al Viro
2020-10-04  2:39   ` [RFC PATCH 14/27] ep_scan_ready_list(): prepare to splitup Al Viro
2020-10-04  2:39   ` [RFC PATCH 15/27] lift the calls of ep_read_events_proc() into the callers Al Viro
2020-10-04  2:39   ` [RFC PATCH 16/27] lift the calls of ep_send_events_proc() " Al Viro
2020-10-04  2:39   ` Al Viro [this message]
2020-10-04  2:39   ` [RFC PATCH 18/27] lift locking/unlocking ep->mtx out of ep_{start,done}_scan() Al Viro
2020-10-04  2:39   ` [RFC PATCH 19/27] ep_insert(): don't open-code ep_remove() on failure exits Al Viro
2020-10-04  2:39   ` [RFC PATCH 20/27] ep_insert(): we only need tep->mtx around the insertion itself Al Viro
2020-10-04 12:56     ` [ep_insert()] 9ee1cc5666: WARNING:possible_recursive_locking_detected kernel test robot
2020-10-04 14:17       ` Al Viro
2020-10-04 14:27         ` Al Viro
2020-10-04  2:39   ` [RFC PATCH 21/27] take the common part of ep_eventpoll_poll() and ep_item_poll() into helper Al Viro
2020-10-04  2:39   ` [RFC PATCH 22/27] fold ep_read_events_proc() into the only caller Al Viro
2020-10-04  2:39   ` [RFC PATCH 23/27] ep_insert(): move creation of wakeup source past the fl_ep_links insertion Al Viro
2020-10-04  2:39   ` [RFC PATCH 24/27] convert ->f_ep_links/->fllink to hlist Al Viro
2020-10-04  2:39   ` [RFC PATCH 25/27] lift rcu_read_lock() into reverse_path_check() Al Viro
2020-10-04  2:39   ` [RFC PATCH 26/27] epoll: massage the check list insertion Al Viro
2020-10-04  2:39   ` [RFC PATCH 27/27] epoll: take epitem list out of struct file Al Viro
2020-10-05 20:37     ` Qian Cai
2020-10-05 20:49       ` Al Viro
2020-10-04  2:49 ` [RFC][PATCHSET] epoll cleanups Al Viro
2020-10-04 12:13 ` Matthew Wilcox
2020-10-04 14:15   ` Al Viro
2020-10-04 18:08 ` Linus Torvalds
2020-10-04 20:05   ` Al Viro

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