From ffbe4a539f69fa3e2f3be74627ca2c830f9d923b Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 7 Aug 2013 16:43:22 +0800 Subject: [PATCH] vxlan: fix a soft lockup in vxlan module removal This is a regression introduced by: commit fe5c3561e6f0ac7c9546209f01351113c1b77ec8 Author: stephen hemminger Date: Sat Jul 13 10:18:18 2013 -0700 vxlan: add necessary locking on device removal The problem is that vxlan_dellink(), which is called with RTNL lock held, tries to flush the workqueue synchronously, but apparently igmp_join and igmp_leave work need to hold RTNL lock too, therefore we have a soft lockup! As suggested by Stephen, probably the flush_workqueue can just be removed and let the normal refcounting work. The workqueue has a reference to device and socket, therefore the cleanups should work correctly. Suggested-by: Stephen Hemminger Cc: Stephen Hemminger Cc: David S. Miller Tested-by: Cong Wang Signed-off-by: Cong Wang Acked-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 11a6c03..767f7af 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1793,8 +1793,6 @@ static void vxlan_dellink(struct net_device *dev, struct list_head *head) struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id); struct vxlan_dev *vxlan = netdev_priv(dev); - flush_workqueue(vxlan_wq); - spin_lock(&vn->sock_lock); hlist_del_rcu(&vxlan->hlist); spin_unlock(&vn->sock_lock); -- 2.7.4