[PATCH] Evict tmp variable from the stack in ip6_evictor

[PATCH] Evict tmp variable from the stack in ip6_evictor

[Pavel Emelyanov]

The list_head *tmp is used to help getting the first entry in
the ip6_frag_lru_list list. There is a simpler way to do it.

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

---

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 31601c9..8fad98b 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -261,7 +261,6 @@ static __inline__ void fq_kill(struct fr
 static void ip6_evictor(struct inet6_dev *idev)
 {
 	struct frag_queue *fq;
-	struct list_head *tmp;
 	int work;
 
 	work = atomic_read(&ip6_frag_mem) - sysctl_ip6frag_low_thresh;
@@ -274,8 +273,9 @@ static void ip6_evictor(struct inet6_dev
 			read_unlock(&ip6_frag_lock);
 			return;
 		}
-		tmp = ip6_frag_lru_list.next;
-		fq = list_entry(tmp, struct frag_queue, lru_list);
+
+		fq = list_first_entry(&ip6_frag_lru_list,
+				struct frag_queue, lru_list);
 		atomic_inc(&fq->refcnt);
 		read_unlock(&ip6_frag_lock);
 

Re: [PATCH] Evict tmp variable from the stack in ip6_evictor

[Patrick McHardy]

Pavel Emelyanov wrote:
> The list_head *tmp is used to help getting the first entry in
> the ip6_frag_lru_list list. There is a simpler way to do it


The exact same code exists in ip_fragment.c and nf_conntrack_reasm.c,
please also change it there.

Re: [PATCH] Evict tmp variable from the stack in ip6_evictor

[Pavel Emelyanov]

Patrick McHardy wrote:
> Pavel Emelyanov wrote:
>> The list_head *tmp is used to help getting the first entry in
>> the ip6_frag_lru_list list. There is a simpler way to do it
> 
> 
> The exact same code exists in ip_fragment.c and nf_conntrack_reasm.c,
> please also change it there.

Hm, indeed. But I see that the structs frag_queue in reassembly.c, ipq 
in ip_fragment.c and nf_ct_frag6_queue in nf code looks VERY similar 
and very much of code (like link/unlink or evict) looks the same too.

Maybe it's worth creating something like struct skb_fragment and
consolidate all the common stuff into some net/core/lib_frag.c? Or
is there some hidden reason for keeping this code splitted?

Thanks, 
Pavel

Re: [PATCH] Evict tmp variable from the stack in ip6_evictor

[Patrick McHardy]

Pavel Emelyanov wrote:
> Patrick McHardy wrote:
>> Pavel Emelyanov wrote:
>>> The list_head *tmp is used to help getting the first entry in
>>> the ip6_frag_lru_list list. There is a simpler way to do it
>>
>> The exact same code exists in ip_fragment.c and nf_conntrack_reasm.c,
>> please also change it there.
> 
> Hm, indeed. But I see that the structs frag_queue in reassembly.c, ipq 
> in ip_fragment.c and nf_ct_frag6_queue in nf code looks VERY similar 
> and very much of code (like link/unlink or evict) looks the same too.
> 
> Maybe it's worth creating something like struct skb_fragment and
> consolidate all the common stuff into some net/core/lib_frag.c? Or
> is there some hidden reason for keeping this code splitted?


I'm not sure if its possible between IPv4 and IPv6, but sharing code
between IPv6 reassembly and netfilter/ipv6 would be nice.

Re: [PATCH] Evict tmp variable from the stack in ip6_evictor

[David Miller]

From: Patrick McHardy <kaber@trash.net>
Date: Wed, 10 Oct 2007 17:06:07 +0200

> Pavel Emelyanov wrote:
> > Patrick McHardy wrote:
> >> Pavel Emelyanov wrote:
> >>> The list_head *tmp is used to help getting the first entry in
> >>> the ip6_frag_lru_list list. There is a simpler way to do it
> >>
> >> The exact same code exists in ip_fragment.c and nf_conntrack_reasm.c,
> >> please also change it there.
> > 
> > Hm, indeed. But I see that the structs frag_queue in reassembly.c, ipq 
> > in ip_fragment.c and nf_ct_frag6_queue in nf code looks VERY similar 
> > and very much of code (like link/unlink or evict) looks the same too.
> > 
> > Maybe it's worth creating something like struct skb_fragment and
> > consolidate all the common stuff into some net/core/lib_frag.c? Or
> > is there some hidden reason for keeping this code splitted?
> 
> I'm not sure if its possible between IPv4 and IPv6, but sharing code
> between IPv6 reassembly and netfilter/ipv6 would be nice.

And besides I think it's an independant change to this tmp
variable removal, so let's just do that first.