1 files changed, 114 insertions, 115 deletions

diff --git a/net/ipv4/ipvs/ip_vs_lblcr.c b/net/ipv4/ipvs/ip_vs_lblcr.c
index f1c845036898..375a1ffb6b65 100644
--- a/net/ipv4/ipvs/ip_vs_lblcr.c
+++ b/net/ipv4/ipvs/ip_vs_lblcr.c
@@ -106,7 +106,7 @@ ip_vs_dest_set_insert(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
 			return NULL;
 	}
 
-	e = kmalloc(sizeof(struct ip_vs_dest_list), GFP_ATOMIC);
+	e = kmalloc(sizeof(*e), GFP_ATOMIC);
 	if (e == NULL) {
 		IP_VS_ERR("ip_vs_dest_set_insert(): no memory\n");
 		return NULL;
@@ -116,11 +116,9 @@ ip_vs_dest_set_insert(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
 	e->dest = dest;
 
 	/* link it to the list */
-	write_lock(&set->lock);
 	e->next = set->list;
 	set->list = e;
 	atomic_inc(&set->size);
-	write_unlock(&set->lock);
 
 	set->lastmod = jiffies;
 	return e;
@@ -131,7 +129,6 @@ ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
 {
 	struct ip_vs_dest_list *e, **ep;
 
-	write_lock(&set->lock);
 	for (ep=&set->list, e=*ep; e!=NULL; e=*ep) {
 		if (e->dest == dest) {
 			/* HIT */
@@ -144,7 +141,6 @@ ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
 		}
 		ep = &e->next;
 	}
-	write_unlock(&set->lock);
 }
 
 static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set)
@@ -174,7 +170,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
 	if (set == NULL)
 		return NULL;
 
-	read_lock(&set->lock);
 	/* select the first destination server, whose weight > 0 */
 	for (e=set->list; e!=NULL; e=e->next) {
 		least = e->dest;
@@ -188,7 +183,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
 			goto nextstage;
 		}
 	}
-	read_unlock(&set->lock);
 	return NULL;
 
 	/* find the destination with the weighted least load */
@@ -207,7 +201,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
 			loh = doh;
 		}
 	}
-	read_unlock(&set->lock);
 
 	IP_VS_DBG(6, "ip_vs_dest_set_min: server %d.%d.%d.%d:%d "
 		  "activeconns %d refcnt %d weight %d overhead %d\n",
@@ -229,7 +222,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
 	if (set == NULL)
 		return NULL;
 
-	read_lock(&set->lock);
 	/* select the first destination server, whose weight > 0 */
 	for (e=set->list; e!=NULL; e=e->next) {
 		most = e->dest;
@@ -239,7 +231,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
 			goto nextstage;
 		}
 	}
-	read_unlock(&set->lock);
 	return NULL;
 
 	/* find the destination with the weighted most load */
@@ -256,7 +247,6 @@ static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
 			moh = doh;
 		}
 	}
-	read_unlock(&set->lock);
 
 	IP_VS_DBG(6, "ip_vs_dest_set_max: server %d.%d.%d.%d:%d "
 		  "activeconns %d refcnt %d weight %d overhead %d\n",
@@ -284,7 +274,6 @@ struct ip_vs_lblcr_entry {
  *      IPVS lblcr hash table
  */
 struct ip_vs_lblcr_table {
-	rwlock_t	        lock;           /* lock for this table */
 	struct list_head        bucket[IP_VS_LBLCR_TAB_SIZE];  /* hash bucket */
 	atomic_t                entries;        /* number of entries */
 	int                     max_size;       /* maximum size of entries */
@@ -311,32 +300,6 @@ static ctl_table vs_vars_table[] = {
 
 static struct ctl_table_header * sysctl_header;
 
-/*
- *      new/free a ip_vs_lblcr_entry, which is a mapping of a destination
- *      IP address to a server.
- */
-static inline struct ip_vs_lblcr_entry *ip_vs_lblcr_new(__be32 daddr)
-{
-	struct ip_vs_lblcr_entry *en;
-
-	en = kmalloc(sizeof(struct ip_vs_lblcr_entry), GFP_ATOMIC);
-	if (en == NULL) {
-		IP_VS_ERR("ip_vs_lblcr_new(): no memory\n");
-		return NULL;
-	}
-
-	INIT_LIST_HEAD(&en->list);
-	en->addr = daddr;
-
-	/* initilize its dest set */
-	atomic_set(&(en->set.size), 0);
-	en->set.list = NULL;
-	rwlock_init(&en->set.lock);
-
-	return en;
-}
-
-
 static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en)
 {
 	list_del(&en->list);
@@ -358,55 +321,68 @@ static inline unsigned ip_vs_lblcr_hashkey(__be32 addr)
  *	Hash an entry in the ip_vs_lblcr_table.
  *	returns bool success.
  */
-static int
+static void
 ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en)
 {
-	unsigned hash;
-
-	if (!list_empty(&en->list)) {
-		IP_VS_ERR("ip_vs_lblcr_hash(): request for already hashed, "
-			  "called from %p\n", __builtin_return_address(0));
-		return 0;
-	}
+	unsigned hash = ip_vs_lblcr_hashkey(en->addr);
 
-	/*
-	 *	Hash by destination IP address
-	 */
-	hash = ip_vs_lblcr_hashkey(en->addr);
-
-	write_lock(&tbl->lock);
 	list_add(&en->list, &tbl->bucket[hash]);
 	atomic_inc(&tbl->entries);
-	write_unlock(&tbl->lock);
-
-	return 1;
 }
 
 
 /*
- *  Get ip_vs_lblcr_entry associated with supplied parameters.
+ *  Get ip_vs_lblcr_entry associated with supplied parameters. Called under
+ *  read lock.
  */
 static inline struct ip_vs_lblcr_entry *
 ip_vs_lblcr_get(struct ip_vs_lblcr_table *tbl, __be32 addr)
 {
-	unsigned hash;
+	unsigned hash = ip_vs_lblcr_hashkey(addr);
 	struct ip_vs_lblcr_entry *en;
 
-	hash = ip_vs_lblcr_hashkey(addr);
+	list_for_each_entry(en, &tbl->bucket[hash], list)
+		if (en->addr == addr)
+			return en;
+
+	return NULL;
+}
 
-	read_lock(&tbl->lock);
 
-	list_for_each_entry(en, &tbl->bucket[hash], list) {
-		if (en->addr == addr) {
-			/* HIT */
-			read_unlock(&tbl->lock);
-			return en;
+/*
+ * Create or update an ip_vs_lblcr_entry, which is a mapping of a destination
+ * IP address to a server. Called under write lock.
+ */
+static inline struct ip_vs_lblcr_entry *
+ip_vs_lblcr_new(struct ip_vs_lblcr_table *tbl,  __be32 daddr,
+		struct ip_vs_dest *dest)
+{
+	struct ip_vs_lblcr_entry *en;
+
+	en = ip_vs_lblcr_get(tbl, daddr);
+	if (!en) {
+		en = kmalloc(sizeof(*en), GFP_ATOMIC);
+		if (!en) {
+			IP_VS_ERR("ip_vs_lblcr_new(): no memory\n");
+			return NULL;
 		}
+
+		en->addr = daddr;
+		en->lastuse = jiffies;
+
+		/* initilize its dest set */
+		atomic_set(&(en->set.size), 0);
+		en->set.list = NULL;
+		rwlock_init(&en->set.lock);
+
+		ip_vs_lblcr_hash(tbl, en);
 	}
 
-	read_unlock(&tbl->lock);
+	write_lock(&en->set.lock);
+	ip_vs_dest_set_insert(&en->set, dest);
+	write_unlock(&en->set.lock);
 
-	return NULL;
+	return en;
 }
 
 
@@ -418,19 +394,18 @@ static void ip_vs_lblcr_flush(struct ip_vs_lblcr_table *tbl)
 	int i;
 	struct ip_vs_lblcr_entry *en, *nxt;
 
+	/* No locking required, only called during cleanup. */
 	for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) {
-		write_lock(&tbl->lock);
 		list_for_each_entry_safe(en, nxt, &tbl->bucket[i], list) {
 			ip_vs_lblcr_free(en);
-			atomic_dec(&tbl->entries);
 		}
-		write_unlock(&tbl->lock);
 	}
 }
 
 
-static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl)
+static inline void ip_vs_lblcr_full_check(struct ip_vs_service *svc)
 {
+	struct ip_vs_lblcr_table *tbl = svc->sched_data;
 	unsigned long now = jiffies;
 	int i, j;
 	struct ip_vs_lblcr_entry *en, *nxt;
@@ -438,7 +413,7 @@ static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl)
 	for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) {
 		j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
 
-		write_lock(&tbl->lock);
+		write_lock(&svc->sched_lock);
 		list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) {
 			if (time_after(en->lastuse+sysctl_ip_vs_lblcr_expiration,
 				       now))
@@ -447,7 +422,7 @@ static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl)
 			ip_vs_lblcr_free(en);
 			atomic_dec(&tbl->entries);
 		}
-		write_unlock(&tbl->lock);
+		write_unlock(&svc->sched_lock);
 	}
 	tbl->rover = j;
 }
@@ -466,17 +441,16 @@ static inline void ip_vs_lblcr_full_check(struct ip_vs_lblcr_table *tbl)
  */
 static void ip_vs_lblcr_check_expire(unsigned long data)
 {
-	struct ip_vs_lblcr_table *tbl;
+	struct ip_vs_service *svc = (struct ip_vs_service *) data;
+	struct ip_vs_lblcr_table *tbl = svc->sched_data;
 	unsigned long now = jiffies;
 	int goal;
 	int i, j;
 	struct ip_vs_lblcr_entry *en, *nxt;
 
-	tbl = (struct ip_vs_lblcr_table *)data;
-
 	if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) {
 		/* do full expiration check */
-		ip_vs_lblcr_full_check(tbl);
+		ip_vs_lblcr_full_check(svc);
 		tbl->counter = 1;
 		goto out;
 	}
@@ -493,7 +467,7 @@ static void ip_vs_lblcr_check_expire(unsigned long data)
 	for (i=0, j=tbl->rover; i<IP_VS_LBLCR_TAB_SIZE; i++) {
 		j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
 
-		write_lock(&tbl->lock);
+		write_lock(&svc->sched_lock);
 		list_for_each_entry_safe(en, nxt, &tbl->bucket[j], list) {
 			if (time_before(now, en->lastuse+ENTRY_TIMEOUT))
 				continue;
@@ -502,7 +476,7 @@ static void ip_vs_lblcr_check_expire(unsigned long data)
 			atomic_dec(&tbl->entries);
 			goal--;
 		}
-		write_unlock(&tbl->lock);
+		write_unlock(&svc->sched_lock);
 		if (goal <= 0)
 			break;
 	}
@@ -520,15 +494,14 @@ static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc)
 	/*
 	 *    Allocate the ip_vs_lblcr_table for this service
 	 */
-	tbl = kmalloc(sizeof(struct ip_vs_lblcr_table), GFP_ATOMIC);
+	tbl = kmalloc(sizeof(*tbl), GFP_ATOMIC);
 	if (tbl == NULL) {
 		IP_VS_ERR("ip_vs_lblcr_init_svc(): no memory\n");
 		return -ENOMEM;
 	}
 	svc->sched_data = tbl;
 	IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) allocated for "
-		  "current service\n",
-		  sizeof(struct ip_vs_lblcr_table));
+		  "current service\n", sizeof(*tbl));
 
 	/*
 	 *    Initialize the hash buckets
@@ -536,7 +509,6 @@ static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc)
 	for (i=0; i<IP_VS_LBLCR_TAB_SIZE; i++) {
 		INIT_LIST_HEAD(&tbl->bucket[i]);
 	}
-	rwlock_init(&tbl->lock);
 	tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16;
 	tbl->rover = 0;
 	tbl->counter = 1;
@@ -545,9 +517,8 @@ static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc)
 	 *    Hook periodic timer for garbage collection
 	 */
 	setup_timer(&tbl->periodic_timer, ip_vs_lblcr_check_expire,
-			(unsigned long)tbl);
-	tbl->periodic_timer.expires = jiffies+CHECK_EXPIRE_INTERVAL;
-	add_timer(&tbl->periodic_timer);
+			(unsigned long)svc);
+	mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL);
 
 	return 0;
 }
@@ -564,9 +535,9 @@ static int ip_vs_lblcr_done_svc(struct ip_vs_service *svc)
 	ip_vs_lblcr_flush(tbl);
 
 	/* release the table itself */
-	kfree(svc->sched_data);
+	kfree(tbl);
 	IP_VS_DBG(6, "LBLCR hash table (memory=%Zdbytes) released\n",
-		  sizeof(struct ip_vs_lblcr_table));
+		  sizeof(*tbl));
 
 	return 0;
 }
@@ -663,50 +634,78 @@ is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc)
 static struct ip_vs_dest *
 ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
 {
-	struct ip_vs_dest *dest;
-	struct ip_vs_lblcr_table *tbl;
-	struct ip_vs_lblcr_entry *en;
+	struct ip_vs_lblcr_table *tbl = svc->sched_data;
 	struct iphdr *iph = ip_hdr(skb);
+	struct ip_vs_dest *dest = NULL;
+	struct ip_vs_lblcr_entry *en;
 
 	IP_VS_DBG(6, "ip_vs_lblcr_schedule(): Scheduling...\n");
 
-	tbl = (struct ip_vs_lblcr_table *)svc->sched_data;
+	/* First look in our cache */
+	read_lock(&svc->sched_lock);
 	en = ip_vs_lblcr_get(tbl, iph->daddr);
-	if (en == NULL) {
-		dest = __ip_vs_lblcr_schedule(svc, iph);
-		if (dest == NULL) {
-			IP_VS_DBG(1, "no destination available\n");
-			return NULL;
-		}
-		en = ip_vs_lblcr_new(iph->daddr);
-		if (en == NULL) {
-			return NULL;
-		}
-		ip_vs_dest_set_insert(&en->set, dest);
-		ip_vs_lblcr_hash(tbl, en);
-	} else {
+	if (en) {
+		/* We only hold a read lock, but this is atomic */
+		en->lastuse = jiffies;
+
+		/* Get the least loaded destination */
+		read_lock(&en->set.lock);
 		dest = ip_vs_dest_set_min(&en->set);
-		if (!dest || is_overloaded(dest, svc)) {
-			dest = __ip_vs_lblcr_schedule(svc, iph);
-			if (dest == NULL) {
-				IP_VS_DBG(1, "no destination available\n");
-				return NULL;
-			}
-			ip_vs_dest_set_insert(&en->set, dest);
-		}
+		read_unlock(&en->set.lock);
+
+		/* More than one destination + enough time passed by, cleanup */
 		if (atomic_read(&en->set.size) > 1 &&
-		    jiffies-en->set.lastmod > sysctl_ip_vs_lblcr_expiration) {
+				time_after(jiffies, en->set.lastmod +
+				sysctl_ip_vs_lblcr_expiration)) {
 			struct ip_vs_dest *m;
+
+			write_lock(&en->set.lock);
 			m = ip_vs_dest_set_max(&en->set);
 			if (m)
 				ip_vs_dest_set_erase(&en->set, m);
+			write_unlock(&en->set.lock);
+		}
+
+		/* If the destination is not overloaded, use it */
+		if (dest && !is_overloaded(dest, svc)) {
+			read_unlock(&svc->sched_lock);
+			goto out;
+		}
+
+		/* The cache entry is invalid, time to schedule */
+		dest = __ip_vs_lblcr_schedule(svc, iph);
+		if (!dest) {
+			IP_VS_DBG(1, "no destination available\n");
+			read_unlock(&svc->sched_lock);
+			return NULL;
 		}
+
+		/* Update our cache entry */
+		write_lock(&en->set.lock);
+		ip_vs_dest_set_insert(&en->set, dest);
+		write_unlock(&en->set.lock);
+	}
+	read_unlock(&svc->sched_lock);
+
+	if (dest)
+		goto out;
+
+	/* No cache entry, time to schedule */
+	dest = __ip_vs_lblcr_schedule(svc, iph);
+	if (!dest) {
+		IP_VS_DBG(1, "no destination available\n");
+		return NULL;
 	}
-	en->lastuse = jiffies;
 
+	/* If we fail to create a cache entry, we'll just use the valid dest */
+	write_lock(&svc->sched_lock);
+	ip_vs_lblcr_new(tbl, iph->daddr, dest);
+	write_unlock(&svc->sched_lock);
+
+out:
 	IP_VS_DBG(6, "LBLCR: destination IP address %u.%u.%u.%u "
 		  "--> server %u.%u.%u.%u:%d\n",
-		  NIPQUAD(en->addr),
+		  NIPQUAD(iph->daddr),
 		  NIPQUAD(dest->addr),
 		  ntohs(dest->port));