netdev - [PATCH v2 3/6] netpoll: Move rx enable/disable into __dev_close

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Date:	Thu, 27 Mar 2014 15:38:17 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	David Miller <davem@...emloft.net>
Cc:	stephen@...workplumber.org, eric.dumazet@...il.com,
	netdev@...r.kernel.org, xiyou.wangcong@...il.com, mpm@...enic.com,
	satyam.sharma@...il.com
Subject: [PATCH v2 3/6] netpoll: Move rx enable/disable into __dev_close_many


Today netpoll_rx_enable and netpoll_rx_disable are called from
dev_close and and __dev_close, and not from dev_close_many.

Move the calls into __dev_close_many so that we have a single call
site to maintain, and so that dev_close_many gains this protection as
well.  Which importantly makes batched network device deletes safe.

Signed-off-by: "Eric W. Biederman" <ebiederm@...ssion.com>
---
 net/core/dev.c |   13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 48dd323d5918..f33dd7382498 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1313,6 +1313,9 @@ static int __dev_close_many(struct list_head *head)
 	might_sleep();
 
 	list_for_each_entry(dev, head, close_list) {
+		/* Temporarily disable netpoll until the interface is down */
+		netpoll_rx_disable(dev);
+
 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
 
 		clear_bit(__LINK_STATE_START, &dev->state);
@@ -1343,6 +1346,7 @@ static int __dev_close_many(struct list_head *head)
 
 		dev->flags &= ~IFF_UP;
 		net_dmaengine_put();
+		netpoll_rx_enable(dev);
 	}
 
 	return 0;
@@ -1353,14 +1357,10 @@ static int __dev_close(struct net_device *dev)
 	int retval;
 	LIST_HEAD(single);
 
-	/* Temporarily disable netpoll until the interface is down */
-	netpoll_rx_disable(dev);
-
 	list_add(&dev->close_list, &single);
 	retval = __dev_close_many(&single);
 	list_del(&single);
 
-	netpoll_rx_enable(dev);
 	return retval;
 }
 
@@ -1398,14 +1398,9 @@ int dev_close(struct net_device *dev)
 	if (dev->flags & IFF_UP) {
 		LIST_HEAD(single);
 
-		/* Block netpoll rx while the interface is going down */
-		netpoll_rx_disable(dev);
-
 		list_add(&dev->close_list, &single);
 		dev_close_many(&single);
 		list_del(&single);
-
-		netpoll_rx_enable(dev);
 	}
 	return 0;
 }
-- 
1.7.10.4

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