net/dst: dst_dev_event() called after other notifiers
authorEric Dumazet <eric.dumazet@gmail.com>
Tue, 9 Nov 2010 19:46:33 +0000 (11:46 -0800)
committerGreg Kroah-Hartman <gregkh@suse.de>
Fri, 7 Jan 2011 21:58:29 +0000 (13:58 -0800)
commit948ac19ea40013395fd277d43fd9ea3c3dcb491a
tree44ef4328298af985c78a16207a54ee806ce6e999
parent5749c7a48207e21c7a98b07ff21c51ee20ed0bff
net/dst: dst_dev_event() called after other notifiers

[ Upstream commit 332dd96f7ac15e937088fe11f15cfe0210e8edd1 ]

Followup of commit ef885afbf8a37689 (net: use rcu_barrier() in
rollback_registered_many)

dst_dev_event() scans a garbage dst list that might be feeded by various
network notifiers at device dismantle time.

Its important to call dst_dev_event() after other notifiers, or we might
enter the infamous msleep(250) in netdev_wait_allrefs(), and wait one
second before calling again call_netdevice_notifiers(NETDEV_UNREGISTER,
dev) to properly remove last device references.

Use priority -10 to let dst_dev_notifier be called after other network
notifiers (they have the default 0 priority)

Reported-by: Ben Greear <greearb@candelatech.com>
Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reported-by: Octavian Purdila <opurdila@ixiacom.com>
Reported-by: Benjamin LaHaise <bcrl@kvack.org>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
net/core/dst.c