net: frag, move LRU list maintenance outside of rwlock

Updating the fragmentation queues LRU (Least-Recently-Used) list,
required taking the hash writer lock.  However, the LRU list isn't
tied to the hash at all, so we can use a separate lock for it.

Original-idea-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 3 insertions, 6 deletions

diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 07ef2949c946..c674f158efa8 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -328,9 +328,8 @@ found:
                 fq->nhoffset = nhoff;
                 fq->q.last_in |= INET_FRAG_FIRST_IN;
         }
-        write_lock(&nf_frags.lock);
-        list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
-        write_unlock(&nf_frags.lock);
+
+        inet_frag_lru_move(&fq->q);
         return 0;
 
 discard_fq:
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 18cb8defcdb2..bab2c270f292 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -341,9 +341,7 @@ found:
             fq->q.meat == fq->q.len)
                 return ip6_frag_reasm(fq, prev, dev);
 
-        write_lock(&ip6_frags.lock);
-        list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
-        write_unlock(&ip6_frags.lock);
+        inet_frag_lru_move(&fq->q);
         return -1;
 
 discard_fq: