[PATCH] ip_gre: fix percpu stats accounting

[PATCH] ip_gre: fix percpu stats accounting

[Pavel Emelyanov]

commit e985aad7 (ip_gre: percpu stats accounting) forgot the fallback
tunnel case (gre0).

This is the 4th part of the "foo: fix percpu stats accounting" series ;)

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 01087e0..be05d5b 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1321,7 +1321,7 @@ static int ipgre_tunnel_init(struct net_device *dev)
 	return 0;
 }
 
-static void ipgre_fb_tunnel_init(struct net_device *dev)
+static int ipgre_fb_tunnel_init(struct net_device *dev)
 {
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 	struct iphdr *iph = &tunnel->parms.iph;
@@ -1335,8 +1335,13 @@ static void ipgre_fb_tunnel_init(struct net_device *dev)
 	iph->ihl		= 5;
 	tunnel->hlen		= sizeof(struct iphdr) + 4;
 
+	dev->tstats = alloc_percpu(struct pcpu_tstats);
+	if (!dev->tstats)
+		return -ENOMEM;
+
 	dev_hold(dev);
 	rcu_assign_pointer(ign->tunnels_wc[0], tunnel);
+	return 0;
 }
 
 
@@ -1377,7 +1382,10 @@ static int __net_init ipgre_init_net(struct net *net)
 	}
 	dev_net_set(ign->fb_tunnel_dev, net);
 
-	ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
+	err = ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
+	if (err)
+		goto err_reg_dev;
+
 	ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
 
 	if ((err = register_netdev(ign->fb_tunnel_dev)))
@@ -1386,7 +1394,7 @@ static int __net_init ipgre_init_net(struct net *net)
 	return 0;
 
 err_reg_dev:
-	free_netdev(ign->fb_tunnel_dev);
+	ipgre_dev_free(ign->fb_tunnel_dev);
 err_alloc_dev:
 	return err;
 }

Re: [PATCH] ip_gre: fix percpu stats accounting

[Eric Dumazet]

Le jeudi 28 octobre 2010 à 20:07 +0400, Pavel Emelyanov a écrit :
> commit e985aad7 (ip_gre: percpu stats accounting) forgot the fallback
> tunnel case (gre0).
> 
> This is the 4th part of the "foo: fix percpu stats accounting" series ;)
> 
> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
> 

Indeed, right you are ;)

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Anyway, I suspect more work is needed...

(check patch against ixgbe : http://patchwork.ozlabs.org/patch/69458/ )

Re: [PATCH] ip_gre: fix percpu stats accounting

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 28 Oct 2010 18:33:54 +0200

> Le jeudi 28 octobre 2010 à 20:07 +0400, Pavel Emelyanov a écrit :
>> commit e985aad7 (ip_gre: percpu stats accounting) forgot the fallback
>> tunnel case (gre0).
>> 
>> This is the 4th part of the "foo: fix percpu stats accounting" series ;)
>> 
>> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
>> 
> 
> Indeed, right you are ;)
> 
> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Applied.

Re: [PATCH] ip_gre: fix percpu stats accounting

[Eric Dumazet]

Le jeudi 28 octobre 2010 à 10:29 -0700, David Miller a écrit :
> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Thu, 28 Oct 2010 18:33:54 +0200
> 
> > Le jeudi 28 octobre 2010 à 20:07 +0400, Pavel Emelyanov a écrit :
> >> commit e985aad7 (ip_gre: percpu stats accounting) forgot the fallback
> >> tunnel case (gre0).
> >> 
> >> This is the 4th part of the "foo: fix percpu stats accounting" series ;)
> >> 
> >> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
> >> 
> > 
> > Indeed, right you are ;)
> > 
> > Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
> 
> Applied.


Hmm, actually patch is buggy, sorry...

Re: [PATCH] ip_gre: fix percpu stats accounting

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 28 Oct 2010 20:38:58 +0200

> Le jeudi 28 octobre 2010 à 10:29 -0700, David Miller a écrit :
>> From: Eric Dumazet <eric.dumazet@gmail.com>
>> Date: Thu, 28 Oct 2010 18:33:54 +0200
>> 
>> > Le jeudi 28 octobre 2010 à 20:07 +0400, Pavel Emelyanov a écrit :
>> >> commit e985aad7 (ip_gre: percpu stats accounting) forgot the fallback
>> >> tunnel case (gre0).
>> >> 
>> >> This is the 4th part of the "foo: fix percpu stats accounting" series ;)
>> >> 
>> >> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
>> >> 
>> > 
>> > Indeed, right you are ;)
>> > 
>> > Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
>> 
>> Applied.
> 
> 
> Hmm, actually patch is buggy, sorry...

I am still able to revert this I think without screwing up
publicly visible history, so I will double check and do the
revert if I can.

Re: [PATCH] ip_gre: fix percpu stats accounting

[Eric Dumazet]

Le jeudi 28 octobre 2010 à 11:41 -0700, David Miller a écrit :
> I am still able to revert this I think without screwing up
> publicly visible history, so I will double check and do the
> revert if I can.

Cool, I'll provide a patch in a couple of minutes, when tested.

Thanks

Re: [PATCH] ip_gre: fix percpu stats accounting

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 28 Oct 2010 20:47:59 +0200

> Le jeudi 28 octobre 2010 à 11:41 -0700, David Miller a écrit :
>> I am still able to revert this I think without screwing up
>> publicly visible history, so I will double check and do the
>> revert if I can.
> 
> Cool, I'll provide a patch in a couple of minutes, when tested.

Thanks.

[PATCH] ip_gre: fix fallback tunnel setup

[Eric Dumazet]

Le jeudi 28 octobre 2010 à 20:47 +0200, Eric Dumazet a écrit :
> Le jeudi 28 octobre 2010 à 11:41 -0700, David Miller a écrit :
> > I am still able to revert this I think without screwing up
> > publicly visible history, so I will double check and do the
> > revert if I can.
> 
> Cool, I'll provide a patch in a couple of minutes, when tested.
> 

I believe the right fix is this one, Pavel what do you think ?

With your patch, we allocate the per_cpu data twice for the fallback
tunnel, thus leaking memory.

Thanks

Note: free_percpu(NULL) is legal

[PATCH] ip_gre: fix fallback tunnel setup

Before making the fallback tunnel visible to lookups, we should make
sure it is completely setup, once ipgre_tunnel_init() had been called
and tstats per_cpu pointer allocated.

move rcu_assign_pointer(ign->tunnels_wc[0], tunnel); from
ipgre_fb_tunnel_init() to ipgre_init_net()

Based on a patch from Pavel Emelyanov

Reported-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
 net/ipv4/ip_gre.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 01087e0..70ff77f 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1325,7 +1325,6 @@ static void ipgre_fb_tunnel_init(struct net_device *dev)
 {
 	struct ip_tunnel *tunnel = netdev_priv(dev);
 	struct iphdr *iph = &tunnel->parms.iph;
-	struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id);
 
 	tunnel->dev = dev;
 	strcpy(tunnel->parms.name, dev->name);
@@ -1336,7 +1335,6 @@ static void ipgre_fb_tunnel_init(struct net_device *dev)
 	tunnel->hlen		= sizeof(struct iphdr) + 4;
 
 	dev_hold(dev);
-	rcu_assign_pointer(ign->tunnels_wc[0], tunnel);
 }
 
 
@@ -1383,10 +1381,12 @@ static int __net_init ipgre_init_net(struct net *net)
 	if ((err = register_netdev(ign->fb_tunnel_dev)))
 		goto err_reg_dev;
 
+	rcu_assign_pointer(ign->tunnels_wc[0],
+			   netdev_priv(ign->fb_tunnel_dev));
 	return 0;
 
 err_reg_dev:
-	free_netdev(ign->fb_tunnel_dev);
+	ipgre_dev_free(ign->fb_tunnel_dev);
 err_alloc_dev:
 	return err;
 }

Re: [PATCH] ip_gre: fix fallback tunnel setup

[Pavel Emelyanov]

On 10/28/2010 11:11 PM, Eric Dumazet wrote:
> Le jeudi 28 octobre 2010 à 20:47 +0200, Eric Dumazet a écrit :
>> Le jeudi 28 octobre 2010 à 11:41 -0700, David Miller a écrit :
>>> I am still able to revert this I think without screwing up
>>> publicly visible history, so I will double check and do the
>>> revert if I can.
>>
>> Cool, I'll provide a patch in a couple of minutes, when tested.
>>
> 
> I believe the right fix is this one, Pavel what do you think ?

Indeed. I missed the fact, that the gre driver uses ndo_init for
all devices including the fb one :(

Acked-by: Pavel Emelyanov <xemul@openvz.org>

> With your patch, we allocate the per_cpu data twice for the fallback
> tunnel, thus leaking memory.

Yup...

> Thanks

Re: [PATCH] ip_gre: fix fallback tunnel setup

[Eric Dumazet]

Le jeudi 28 octobre 2010 à 23:29 +0400, Pavel Emelyanov a écrit :

> Indeed. I missed the fact, that the gre driver uses ndo_init for
> all devices including the fb one :(
> 
> Acked-by: Pavel Emelyanov <xemul@openvz.org>

Well, I discovered this right now, it was not that obvious, maybe we
should use similar setup for all fb tunnels as well...

Thanks !

Re: [PATCH] ip_gre: fix fallback tunnel setup

[David Miller]

From: Pavel Emelyanov <xemul@parallels.com>
Date: Thu, 28 Oct 2010 23:29:10 +0400

> On 10/28/2010 11:11 PM, Eric Dumazet wrote:
>> Le jeudi 28 octobre 2010 à 20:47 +0200, Eric Dumazet a écrit :
>>> Le jeudi 28 octobre 2010 à 11:41 -0700, David Miller a écrit :
>>>> I am still able to revert this I think without screwing up
>>>> publicly visible history, so I will double check and do the
>>>> revert if I can.
>>>
>>> Cool, I'll provide a patch in a couple of minutes, when tested.
>>>
>> 
>> I believe the right fix is this one, Pavel what do you think ?
> 
> Indeed. I missed the fact, that the gre driver uses ndo_init for
> all devices including the fb one :(
> 
> Acked-by: Pavel Emelyanov <xemul@openvz.org>

Applied.