[INET]: Consolidate the xxx_evictor

The evictors collect some statistics for ipv4 and ipv6,
so make it return the number of evicted queues and account
them all at once in the caller.

The XXX_ADD_STATS_BH() macros are just for this case,
but maybe there are places in code, that can make use of
them as well.

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

include/net/inet_frag.h

@@ -49,5 +49,6 @@ void inet_frags_fini(struct inet_frags *);
 void inet_frag_kill(struct inet_frag_queue *q, struct inet_frags *f);
 void inet_frag_destroy(struct inet_frag_queue *q,
 				struct inet_frags *f, int *work);
+int inet_frag_evictor(struct inet_frags *f);
 
 #endif

include/net/ip.h

@@ -160,6 +160,7 @@ DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics);
 #define IP_INC_STATS(field)		SNMP_INC_STATS(ip_statistics, field)
 #define IP_INC_STATS_BH(field)		SNMP_INC_STATS_BH(ip_statistics, field)
 #define IP_INC_STATS_USER(field) 	SNMP_INC_STATS_USER(ip_statistics, field)
+#define IP_ADD_STATS_BH(field, val)	SNMP_ADD_STATS_BH(ip_statistics, field, val)
 DECLARE_SNMP_STAT(struct linux_mib, net_statistics);
 #define NET_INC_STATS(field)		SNMP_INC_STATS(net_statistics, field)
 #define NET_INC_STATS_BH(field)		SNMP_INC_STATS_BH(net_statistics, field)

include/net/ipv6.h

@@ -120,12 +120,21 @@ extern int sysctl_mld_max_msf;
 	SNMP_INC_STATS##modifier(statname##_statistics, (field));	\
 })
 
+#define _DEVADD(statname, modifier, idev, field, val)			\
+({									\
+	struct inet6_dev *_idev = (idev);				\
+	if (likely(_idev != NULL))					\
+		SNMP_ADD_STATS##modifier((_idev)->stats.statname, (field), (val)); \
+	SNMP_ADD_STATS##modifier(statname##_statistics, (field), (val));\
+})
+
 /* MIBs */
 DECLARE_SNMP_STAT(struct ipstats_mib, ipv6_statistics);
 
 #define IP6_INC_STATS(idev,field)	_DEVINC(ipv6, , idev, field)
 #define IP6_INC_STATS_BH(idev,field)	_DEVINC(ipv6, _BH, idev, field)
 #define IP6_INC_STATS_USER(idev,field)	_DEVINC(ipv6, _USER, idev, field)
+#define IP6_ADD_STATS_BH(idev,field,val) _DEVADD(ipv6, _BH, idev, field, val)
 
 DECLARE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics);
 DECLARE_SNMP_STAT(struct icmpv6msg_mib, icmpv6msg_statistics);

net/ipv4/inet_fragment.c

@@ -140,3 +140,35 @@ void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f,
 
 }
 EXPORT_SYMBOL(inet_frag_destroy);
+
+int inet_frag_evictor(struct inet_frags *f)
+{
+	struct inet_frag_queue *q;
+	int work, evicted = 0;
+
+	work = atomic_read(&f->mem) - f->ctl->low_thresh;
+	while (work > 0) {
+		read_lock(&f->lock);
+		if (list_empty(&f->lru_list)) {
+			read_unlock(&f->lock);
+			break;
+		}
+
+		q = list_first_entry(&f->lru_list,
+				struct inet_frag_queue, lru_list);
+		atomic_inc(&q->refcnt);
+		read_unlock(&f->lock);
+
+		spin_lock(&q->lock);
+		if (!(q->last_in & COMPLETE))
+			inet_frag_kill(q, f);
+		spin_unlock(&q->lock);
+
+		if (atomic_dec_and_test(&q->refcnt))
+			inet_frag_destroy(q, f, &work);
+		evicted++;
+	}
+
+	return evicted;
+}
+EXPORT_SYMBOL(inet_frag_evictor);

net/ipv4/ip_fragment.c

@@ -174,33 +174,11 @@ static void ipq_kill(struct ipq *ipq)
  */
 static void ip_evictor(void)
 {
-	struct ipq *qp;
-	struct list_head *tmp;
-	int work;
-
-	work = atomic_read(&ip4_frags.mem) - ip4_frags_ctl.low_thresh;
-	if (work <= 0)
-		return;
-
-	while (work > 0) {
-		read_lock(&ip4_frags.lock);
-		if (list_empty(&ip4_frags.lru_list)) {
-			read_unlock(&ip4_frags.lock);
-			return;
-		}
-		tmp = ip4_frags.lru_list.next;
-		qp = list_entry(tmp, struct ipq, q.lru_list);
-		atomic_inc(&qp->q.refcnt);
-		read_unlock(&ip4_frags.lock);
+	int evicted;
 
-		spin_lock(&qp->q.lock);
-		if (!(qp->q.last_in&COMPLETE))
-			ipq_kill(qp);
-		spin_unlock(&qp->q.lock);
-
-		ipq_put(qp, &work);
-		IP_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
-	}
+	evicted = inet_frag_evictor(&ip4_frags);
+	if (evicted)
+		IP_ADD_STATS_BH(IPSTATS_MIB_REASMFAILS, evicted);
 }
 
 /*

net/ipv6/netfilter/nf_conntrack_reasm.c

@@ -163,34 +163,7 @@ static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq)
 
 static void nf_ct_frag6_evictor(void)
 {
-	struct nf_ct_frag6_queue *fq;
-	struct list_head *tmp;
-	unsigned int work;
-
-	work = atomic_read(&nf_frags.mem);
-	if (work <= nf_frags_ctl.low_thresh)
-		return;
-
-	work -= nf_frags_ctl.low_thresh;
-	while (work > 0) {
-		read_lock(&nf_frags.lock);
-		if (list_empty(&nf_frags.lru_list)) {
-			read_unlock(&nf_frags.lock);
-			return;
-		}
-		tmp = nf_frags.lru_list.next;
-		BUG_ON(tmp == NULL);
-		fq = list_entry(tmp, struct nf_ct_frag6_queue, q.lru_list);
-		atomic_inc(&fq->q.refcnt);
-		read_unlock(&nf_frags.lock);
-
-		spin_lock(&fq->q.lock);
-		if (!(fq->q.last_in&COMPLETE))
-			fq_kill(fq);
-		spin_unlock(&fq->q.lock);
-
-		fq_put(fq, &work);
-	}
+	inet_frag_evictor(&nf_frags);
 }
 
 static void nf_ct_frag6_expire(unsigned long data)

net/ipv6/reassembly.c

@@ -185,33 +185,11 @@ static __inline__ void fq_kill(struct frag_queue *fq)
 
 static void ip6_evictor(struct inet6_dev *idev)
 {
-	struct frag_queue *fq;
-	struct list_head *tmp;
-	int work;
-
-	work = atomic_read(&ip6_frags.mem) - ip6_frags_ctl.low_thresh;
-	if (work <= 0)
-		return;
-
-	while(work > 0) {
-		read_lock(&ip6_frags.lock);
-		if (list_empty(&ip6_frags.lru_list)) {
-			read_unlock(&ip6_frags.lock);
-			return;
-		}
-		tmp = ip6_frags.lru_list.next;
-		fq = list_entry(tmp, struct frag_queue, q.lru_list);
-		atomic_inc(&fq->q.refcnt);
-		read_unlock(&ip6_frags.lock);
+	int evicted;
 
-		spin_lock(&fq->q.lock);
-		if (!(fq->q.last_in&COMPLETE))
-			fq_kill(fq);
-		spin_unlock(&fq->q.lock);
-
-		fq_put(fq, &work);
-		IP6_INC_STATS_BH(idev, IPSTATS_MIB_REASMFAILS);
-	}
+	evicted = inet_frag_evictor(&ip6_frags);
+	if (evicted)
+		IP6_ADD_STATS_BH(idev, IPSTATS_MIB_REASMFAILS, evicted);
 }
 
 static void ip6_frag_expire(unsigned long data)