[INET]: Consolidate the xxx_frag_destroy

To make in possible we need to know the exact frag queue
size for inet_frags->mem management and two callbacks:

 * to destoy the skb (optional, used in conntracks only)
 * to free the queue itself (mandatory, but later I plan to
   move the allocation and the destruction of frag_queues
   into the common place, so this callback will most likely
   be optional too).

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

2 files changed, 50 insertions, 29 deletions

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index ec10e05..15fb2c4 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -17,6 +17,8 @@
 #include <linux/timer.h>
 #include <linux/mm.h>
 #include <linux/random.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
 
 #include <net/inet_frag.h>
 
@@ -100,3 +102,41 @@ void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f)
 }
 
 EXPORT_SYMBOL(inet_frag_kill);
+
+static inline void frag_kfree_skb(struct inet_frags *f, struct sk_buff *skb,
+						int *work)
+{
+	if (work)
+		*work -= skb->truesize;
+
+	atomic_sub(skb->truesize, &f->mem);
+	if (f->skb_free)
+		f->skb_free(skb);
+	kfree_skb(skb);
+}
+
+void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f,
+					int *work)
+{
+	struct sk_buff *fp;
+
+	BUG_TRAP(q->last_in & COMPLETE);
+	BUG_TRAP(del_timer(&q->timer) == 0);
+
+	/* Release all fragment data. */
+	fp = q->fragments;
+	while (fp) {
+		struct sk_buff *xp = fp->next;
+
+		frag_kfree_skb(f, fp, work);
+		fp = xp;
+	}
+
+	if (work)
+		*work -= f->qsize;
+	atomic_sub(f->qsize, &f->mem);
+
+	f->destructor(q);
+
+}
+EXPORT_SYMBOL(inet_frag_destroy);
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index e231c24..e873663 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -132,11 +132,13 @@ static __inline__ void frag_kfree_skb(struct sk_buff *skb, int *work)
 	kfree_skb(skb);
 }
 
-static __inline__ void frag_free_queue(struct ipq *qp, int *work)
+static __inline__ void ip4_frag_free(struct inet_frag_queue *q)
 {
-	if (work)
-		*work -= sizeof(struct ipq);
-	atomic_sub(sizeof(struct ipq), &ip4_frags.mem);
+	struct ipq *qp;
+
+	qp = container_of(q, struct ipq, q);
+	if (qp->peer)
+		inet_putpeer(qp->peer);
 	kfree(qp);
 }
 
@@ -153,34 +155,10 @@ static __inline__ struct ipq *frag_alloc_queue(void)
 
 /* Destruction primitives. */
 
-/* Complete destruction of ipq. */
-static void ip_frag_destroy(struct ipq *qp, int *work)
-{
-	struct sk_buff *fp;
-
-	BUG_TRAP(qp->q.last_in&COMPLETE);
-	BUG_TRAP(del_timer(&qp->q.timer) == 0);
-
-	if (qp->peer)
-		inet_putpeer(qp->peer);
-
-	/* Release all fragment data. */
-	fp = qp->q.fragments;
-	while (fp) {
-		struct sk_buff *xp = fp->next;
-
-		frag_kfree_skb(fp, work);
-		fp = xp;
-	}
-
-	/* Finally, release the queue descriptor itself. */
-	frag_free_queue(qp, work);
-}
-
 static __inline__ void ipq_put(struct ipq *ipq, int *work)
 {
 	if (atomic_dec_and_test(&ipq->q.refcnt))
-		ip_frag_destroy(ipq, work);
+		inet_frag_destroy(&ipq->q, &ip4_frags, work);
 }
 
 /* Kill ipq entry. It is not destroyed immediately,
@@ -721,6 +699,9 @@ void __init ipfrag_init(void)
 {
 	ip4_frags.ctl = &ip4_frags_ctl;
 	ip4_frags.hashfn = ip4_hashfn;
+	ip4_frags.destructor = ip4_frag_free;
+	ip4_frags.skb_free = NULL;
+	ip4_frags.qsize = sizeof(struct ipq);
 	inet_frags_init(&ip4_frags);
 }