diff options
| author | Pavel Emelyanov <xemul@parallels.com> | 2012-08-08 21:53:19 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-08-09 16:18:07 -0700 |
| commit | aa79e66eee5d525e2fcbd2a5fcb87ae3dd4aa9e9 (patch) | |
| tree | fd275880600683733adcb1d84477ea35a04dd901 | |
| parent | e6f8f1a739b652c56e6f959d6714d92e05621e21 (diff) | |
net: Make ifindex generation per-net namespace
Strictly speaking this is only _really_ required for checkpoint-restore to
make loopback device always have the same index.
This change appears to be safe wrt "ifindex should be unique per-system"
concept, as all the ifindex usage is either already made per net namespace
of is explicitly limited with init_net only.
There are two cool side effects of this. The first one -- ifindices of
devices in container are always small, regardless of how many containers
we've started (and re-started) so far. The second one is -- we can speed
up the loopback ifidex access as shown in the next patch.
v2: Place ifindex right after dev_base_seq : avoid two holes and use the
same cache line, dirtied in list_netdevice()/unlist_netdevice()
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/net_namespace.h | 1 | ||||
| -rw-r--r-- | net/core/dev.c | 4 |
2 files changed, 3 insertions, 2 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index ae1cd6c9ba52..6dc3db3466bf 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -66,6 +66,7 @@ struct net { struct hlist_head *dev_name_head; struct hlist_head *dev_index_head; unsigned int dev_base_seq; /* protected by rtnl_mutex */ + int ifindex; /* core fib_rules */ struct list_head rules_ops; diff --git a/net/core/dev.c b/net/core/dev.c index 3ca300d85271..1f06df8d10a3 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5221,12 +5221,12 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg) */ static int dev_new_index(struct net *net) { - static int ifindex; + int ifindex = net->ifindex; for (;;) { if (++ifindex <= 0) ifindex = 1; if (!__dev_get_by_index(net, ifindex)) - return ifindex; + return net->ifindex = ifindex; } } |