[INET]: Consolidate xxx_frag_intern

This routine checks for the existence of a given entry
in the hash table and inserts the new one if needed.

The ->equal callback is used to compare two frag_queue-s
together, but this one is temporary and will be removed
later. The netfilter code and the ipv6 one use the same
routine to compare frags.

The inet_frag_intern() always returns non-NULL pointer,
so convert the inet_frag_queue into protocol specific
one (with the container_of) without any checks.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 36 deletions

diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index d12a18b8f56..4b1bbbee22c 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -123,6 +123,20 @@ static unsigned int ip4_hashfn(struct inet_frag_queue *q)
         return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
 }
 
+static int ip4_frag_equal(struct inet_frag_queue *q1,
+                struct inet_frag_queue *q2)
+{
+        struct ipq *qp1, *qp2;
+
+        qp1 = container_of(q1, struct ipq, q);
+        qp2 = container_of(q2, struct ipq, q);
+        return (qp1->id == qp2->id &&
+                        qp1->saddr == qp2->saddr &&
+                        qp1->daddr == qp2->daddr &&
+                        qp1->protocol == qp2->protocol &&
+                        qp1->user == qp2->user);
+}
+
 /* Memory Tracking Functions. */
 static __inline__ void frag_kfree_skb(struct sk_buff *skb, int *work)
 {
@@ -214,43 +228,10 @@ out:
 
 static struct ipq *ip_frag_intern(struct ipq *qp_in, unsigned int hash)
 {
-        struct ipq *qp;
-#ifdef CONFIG_SMP
-        struct hlist_node *n;
-#endif
+        struct inet_frag_queue *q;
 
-        write_lock(&ip4_frags.lock);
-#ifdef CONFIG_SMP
-        /* With SMP race we have to recheck hash table, because
-         * such entry could be created on other cpu, while we
-         * promoted read lock to write lock.
-         */
-        hlist_for_each_entry(qp, n, &ip4_frags.hash[hash], q.list) {
-                if (qp->id == qp_in->id         &&
-                    qp->saddr == qp_in->saddr   &&
-                    qp->daddr == qp_in->daddr   &&
-                    qp->protocol == qp_in->protocol &&
-                    qp->user == qp_in->user) {
-                        atomic_inc(&qp->q.refcnt);
-                        write_unlock(&ip4_frags.lock);
-                        qp_in->q.last_in |= COMPLETE;
-                        ipq_put(qp_in);
-                        return qp;
-                }
-        }
-#endif
-        qp = qp_in;
-
-        if (!mod_timer(&qp->q.timer, jiffies + ip4_frags_ctl.timeout))
-                atomic_inc(&qp->q.refcnt);
-
-        atomic_inc(&qp->q.refcnt);
-        hlist_add_head(&qp->q.list, &ip4_frags.hash[hash]);
-        INIT_LIST_HEAD(&qp->q.lru_list);
-        list_add_tail(&qp->q.lru_list, &ip4_frags.lru_list);
-        ip4_frags.nqueues++;
-        write_unlock(&ip4_frags.lock);
-        return qp;
+        q = inet_frag_intern(&qp_in->q, &ip4_frags, hash);
+        return container_of(q, struct ipq, q);
 }
 
 /* Add an entry to the 'ipq' queue for a newly received IP datagram. */
@@ -671,6 +652,7 @@ void __init ipfrag_init(void)
         ip4_frags.destructor = ip4_frag_free;
         ip4_frags.skb_free = NULL;
         ip4_frags.qsize = sizeof(struct ipq);
+        ip4_frags.equal = ip4_frag_equal;
         inet_frags_init(&ip4_frags);
 }