[3.13.y.z extended stable] Patch "net: Allow for more then a single subclass for netif_addr_lock" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net: Allow for more then a single subclass for netif_addr_lock

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.4.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 76af96786270860c6693d118614b7c34de82b940 Mon Sep 17 00:00:00 2001
From: Vlad Yasevich <vyasevic at redhat.com>
Date: Fri, 16 May 2014 17:04:54 -0400
Subject: net: Allow for more then a single subclass for netif_addr_lock

[ Upstream commit 25175ba5c9bff9aaf0229df34bb5d54c81633ec3 ]

Currently netif_addr_lock_nested assumes that there can be only
a single nesting level between 2 devices.  However, if we
have multiple devices of the same type stacked, this fails.
For example:
 eth0 <-- vlan0.10 <-- vlan0.10.20

A more complicated configuration may stack more then one type of
device in different order.
Ex:
  eth0 <-- vlan0.10 <-- macvlan0 <-- vlan1.10.20 <-- macvlan1

This patch adds an ndo_* function that allows each stackable
device to report its nesting level.  If the device doesn't
provide this function default subclass of 1 is used.

Signed-off-by: Vlad Yasevich <vyasevic at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 include/linux/netdevice.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d7df837..dfc5271 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1128,6 +1128,7 @@ struct net_device_ops {
 	netdev_tx_t		(*ndo_dfwd_start_xmit) (struct sk_buff *skb,
 							struct net_device *dev,
 							void *priv);
+	int			(*ndo_get_lock_subclass)(struct net_device *dev);
 };

 /*
@@ -2742,7 +2743,12 @@ static inline void netif_addr_lock(struct net_device *dev)

 static inline void netif_addr_lock_nested(struct net_device *dev)
 {
-	spin_lock_nested(&dev->addr_list_lock, SINGLE_DEPTH_NESTING);
+	int subclass = SINGLE_DEPTH_NESTING;
+
+	if (dev->netdev_ops->ndo_get_lock_subclass)
+		subclass = dev->netdev_ops->ndo_get_lock_subclass(dev);
+
+	spin_lock_nested(&dev->addr_list_lock, subclass);
 }

 static inline void netif_addr_lock_bh(struct net_device *dev)
--
1.9.1