From: Pavel Emelyanov <xemul@parallels•com>
To: David Miller <davem@davemloft•net>,
Eric Dumazet <eric.dumazet@gmail•com>,
"Eric W. Biederman" <ebiederm@xmission•com>,
Linux Netdev List <netdev@vger•kernel.org>
Subject: [PATCH 4/5 (resend)] net: Make ifindex generation per-net namespace
Date: Tue, 07 Aug 2012 15:02:27 +0400 [thread overview]
Message-ID: <5020F5C3.8010107@parallels.com> (raw)
In-Reply-To: <501FD15F.70604@parallels.com>
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.
Signed-off-by: Pavel Emelyanov <xemul@parallels•com>
---
include/net/net_namespace.h | 1 +
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 ae1cd6c..c5fbebf 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -62,6 +62,7 @@ struct net {
struct sock *rtnl; /* rtnetlink socket */
struct sock *genl_sock;
+ int ifindex;
struct list_head dev_base_head;
struct hlist_head *dev_name_head;
struct hlist_head *dev_index_head;
diff --git a/net/core/dev.c b/net/core/dev.c
index 3ca300d..1f06df8 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;
}
}
--
1.7.6.5
next prev parent reply other threads:[~2012-08-07 11:02 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-06 14:13 [PATCH net-next 0/6] Per-net and on-demand link indices (and related) v2 Pavel Emelyanov
2012-08-06 14:13 ` [PATCH 1/6] hash: Introduce ptr_hash_mix routine Pavel Emelyanov
2012-08-06 20:44 ` David Miller
2012-08-07 9:11 ` Pavel Emelyanov
2012-08-07 9:28 ` Eric Dumazet
2012-08-07 9:55 ` Pavel Emelyanov
2012-08-07 10:30 ` Eric Dumazet
2012-08-07 21:39 ` David Miller
2012-08-06 14:14 ` [PATCH 2/6] net: Dont use ifindices in hash fns Pavel Emelyanov
2012-08-06 14:14 ` [PATCH 3/6] net: Allow to create links with given ifindex Pavel Emelyanov
2012-08-07 11:01 ` [PATCH 2/5 (resend)] " Pavel Emelyanov
2012-08-07 13:14 ` Eric Dumazet
2012-08-07 21:42 ` David Miller
2012-08-06 14:14 ` [PATCH 4/6] veth: Allow to create peer link " Pavel Emelyanov
2012-08-07 11:02 ` [PATCH 3/5 (resend)] " Pavel Emelyanov
2012-08-07 13:14 ` Eric Dumazet
2012-08-07 18:36 ` Ben Hutchings
2012-08-08 9:00 ` Pavel Emelyanov
2012-08-08 13:25 ` Ben Hutchings
2012-08-08 13:38 ` Pavel Emelyanov
2012-08-06 14:14 ` [PATCH 5/6] net: Make ifindex generation per-net namespace Pavel Emelyanov
2012-08-07 11:02 ` Pavel Emelyanov [this message]
2012-08-07 12:11 ` [PATCH 4/5 (resend)] " Eric Dumazet
2012-08-07 12:37 ` [PATCH 4/5 (resend)] net: Make ifindex generation per-net namespace (v2) Pavel Emelyanov
2012-08-07 13:13 ` Eric Dumazet
2012-08-06 14:15 ` [PATCH 6/6] net: Loopback ifindex is constant now Pavel Emelyanov
2012-08-07 11:02 ` [PATCH 5/5 (resend)] " Pavel Emelyanov
2012-08-07 13:13 ` Eric Dumazet
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