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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 22/27] fold ep_read_events_proc() into the only caller
Date: Sun,  4 Oct 2020 03:39:24 +0100	[thread overview]
Message-ID: <20201004023929.2740074-22-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>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/eventpoll.c | 49 ++++++++++++++++++++-----------------------------
 1 file changed, 20 insertions(+), 29 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index a50b48d26c55..1efe8a1a022a 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -729,14 +729,17 @@ static int ep_eventpoll_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static __poll_t ep_read_events_proc(struct eventpoll *ep, struct list_head *head,
-			       int depth);
+static __poll_t ep_item_poll(const struct epitem *epi, poll_table *pt, int depth);
 
 static __poll_t __ep_eventpoll_poll(struct file *file, poll_table *wait, int depth)
 {
 	struct eventpoll *ep = file->private_data;
 	LIST_HEAD(txlist);
-	__poll_t res;
+	struct epitem *epi, *tmp;
+	poll_table pt;
+	__poll_t res = 0;
+
+	init_poll_funcptr(&pt, NULL);
 
 	/* Insert inside our poll wait queue */
 	poll_wait(file, &ep->poll_wait, wait);
@@ -747,7 +750,20 @@ static __poll_t __ep_eventpoll_poll(struct file *file, poll_table *wait, int dep
 	 */
 	mutex_lock_nested(&ep->mtx, depth);
 	ep_start_scan(ep, &txlist);
-	res = ep_read_events_proc(ep, &txlist, depth + 1);
+	list_for_each_entry_safe(epi, tmp, &txlist, rdllink) {
+		if (ep_item_poll(epi, &pt, depth + 1)) {
+			res = EPOLLIN | EPOLLRDNORM;
+			break;
+		} else {
+			/*
+			 * Item has been dropped into the ready list by the poll
+			 * callback, but it's not actually ready, as far as
+			 * caller requested events goes. We can remove it here.
+			 */
+			__pm_relax(ep_wakeup_source(epi));
+			list_del_init(&epi->rdllink);
+		}
+	}
 	ep_done_scan(ep, &txlist);
 	mutex_unlock(&ep->mtx);
 	return res;
@@ -772,31 +788,6 @@ static __poll_t ep_item_poll(const struct epitem *epi, poll_table *pt,
 	return res & epi->event.events;
 }
 
-static __poll_t ep_read_events_proc(struct eventpoll *ep, struct list_head *head,
-			       int depth)
-{
-	struct epitem *epi, *tmp;
-	poll_table pt;
-
-	init_poll_funcptr(&pt, NULL);
-
-	list_for_each_entry_safe(epi, tmp, head, rdllink) {
-		if (ep_item_poll(epi, &pt, depth)) {
-			return EPOLLIN | EPOLLRDNORM;
-		} else {
-			/*
-			 * Item has been dropped into the ready list by the poll
-			 * callback, but it's not actually ready, as far as
-			 * caller requested events goes. We can remove it here.
-			 */
-			__pm_relax(ep_wakeup_source(epi));
-			list_del_init(&epi->rdllink);
-		}
-	}
-
-	return 0;
-}
-
 static __poll_t ep_eventpoll_poll(struct file *file, poll_table *wait)
 {
 	return __ep_eventpoll_poll(file, wait, 0);
-- 
2.11.0


  parent reply	other threads:[~2020-10-04  2:40 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   ` [RFC PATCH 17/27] ep_send_events_proc(): fold into the caller Al Viro
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   ` Al Viro [this message]
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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