[PATCH 3.14 082/140] net: Allow for more then a single subclass for netif_addr_lock

Greg Kroah-Hartman
2014-05-29T05:20:55Z

From: Vlad Yasevich <vyasevic@redhat.com>

[ 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@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/netdevice.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1145,6 +1145,7 @@ 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);
};

/*
@@ -2861,7 +2862,12 @@ static inline void netif_addr_lock(struc

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)