---

yaml --- r: 183329 b: refs/heads/master c: 52d58ae h: refs/heads/master i: 183327: 3df31f9 v: v3
git-mirror · Dec 27, 2009 · 25503cf · 25503cf
1 parent a12c627
commit 25503cf
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Showing 6 changed files with 116 additions and 38 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6d2e3ea284463d5ab34e9cf2a41d0b8627b95d02
+refs/heads/master: 52d58aef5ee460fedd7f250f05e79081019f2c79
diff --git a/trunk/include/net/llc.h b/trunk/include/net/llc.h
@@ -17,6 +17,8 @@
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/rculist_nulls.h>
+#include <linux/hash.h>
+#include <linux/jhash.h>
 
 #include <asm/atomic.h>
 
@@ -35,6 +37,9 @@ struct llc_addr {
 #define LLC_SK_DEV_HASH_BITS 6
 #define LLC_SK_DEV_HASH_ENTRIES (1<<LLC_SK_DEV_HASH_BITS)
 
+#define LLC_SK_LADDR_HASH_BITS 6
+#define LLC_SK_LADDR_HASH_ENTRIES (1<<LLC_SK_LADDR_HASH_BITS)
+
 /**
  * struct llc_sap - Defines the SAP component
  *
@@ -58,7 +63,8 @@ struct llc_sap {
 	struct llc_addr	 laddr;
 	struct list_head node;
 	spinlock_t sk_lock;
-	struct hlist_nulls_head sk_list;
+	int sk_count;
+	struct hlist_nulls_head sk_laddr_hash[LLC_SK_LADDR_HASH_ENTRIES];
 	struct hlist_head sk_dev_hash[LLC_SK_DEV_HASH_ENTRIES];
 };
 
@@ -68,6 +74,19 @@ struct hlist_head *llc_sk_dev_hash(struct llc_sap *sap, int ifindex)
 	return &sap->sk_dev_hash[ifindex % LLC_SK_DEV_HASH_ENTRIES];
 }
 
+static inline
+u32 llc_sk_laddr_hashfn(struct llc_sap *sap, const struct llc_addr *laddr)
+{
+	return hash_32(jhash(laddr->mac, sizeof(laddr->mac), 0),
+		       LLC_SK_LADDR_HASH_BITS);
+}
+
+static inline
+struct hlist_nulls_head *llc_sk_laddr_hash(struct llc_sap *sap,
+					   const struct llc_addr *laddr)
+{
+	return &sap->sk_laddr_hash[llc_sk_laddr_hashfn(sap, laddr)];
+}
 
 #define LLC_DEST_INVALID         0      /* Invalid LLC PDU type */
 #define LLC_DEST_SAP             1      /* Type 1 goes here */

diff --git a/trunk/net/llc/llc_conn.c b/trunk/net/llc/llc_conn.c
@@ -498,10 +498,12 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
 {
 	struct sock *rc;
 	struct hlist_nulls_node *node;
+	int slot = llc_sk_laddr_hashfn(sap, laddr);
+	struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
 
 	rcu_read_lock();
 again:
-	sk_nulls_for_each_rcu(rc, node, &sap->sk_list) {
+	sk_nulls_for_each_rcu(rc, node, laddr_hb) {
 		if (llc_estab_match(sap, daddr, laddr, rc)) {
 			/* Extra checks required by SLAB_DESTROY_BY_RCU */
 			if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
@@ -515,6 +517,13 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
 		}
 	}
 	rc = NULL;
+	/*
+	 * if the nulls value we got at the end of this lookup is
+	 * not the expected one, we must restart lookup.
+	 * We probably met an item that was moved to another chain.
+	 */
+	if (unlikely(get_nulls_value(node) != slot))
+		goto again;
 found:
 	rcu_read_unlock();
 	return rc;
@@ -540,29 +549,20 @@ static inline bool llc_listener_match(const struct llc_sap *sap,
 
 	return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
 		llc->laddr.lsap == laddr->lsap &&
-		(llc_mac_match(llc->laddr.mac, laddr->mac) ||
-		 llc_mac_null(llc->laddr.mac));
+		llc_mac_match(llc->laddr.mac, laddr->mac);
 }
 
-/**
- *	llc_lookup_listener - Finds listener for local MAC + SAP
- *	@sap: SAP
- *	@laddr: address of local LLC (MAC + SAP)
- *
- *	Search connection list of the SAP and finds connection listening on
- *	local mac, and local sap. Returns pointer for parent socket found,
- *	%NULL otherwise.
- *	Caller has to make sure local_bh is disabled.
- */
-static struct sock *llc_lookup_listener(struct llc_sap *sap,
-					struct llc_addr *laddr)
+static struct sock *__llc_lookup_listener(struct llc_sap *sap,
+					  struct llc_addr *laddr)
 {
 	struct sock *rc;
 	struct hlist_nulls_node *node;
+	int slot = llc_sk_laddr_hashfn(sap, laddr);
+	struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
 
 	rcu_read_lock();
 again:
-	sk_nulls_for_each_rcu(rc, node, &sap->sk_list) {
+	sk_nulls_for_each_rcu(rc, node, laddr_hb) {
 		if (llc_listener_match(sap, laddr, rc)) {
 			/* Extra checks required by SLAB_DESTROY_BY_RCU */
 			if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
@@ -576,11 +576,40 @@ static struct sock *llc_lookup_listener(struct llc_sap *sap,
 		}
 	}
 	rc = NULL;
+	/*
+	 * if the nulls value we got at the end of this lookup is
+	 * not the expected one, we must restart lookup.
+	 * We probably met an item that was moved to another chain.
+	 */
+	if (unlikely(get_nulls_value(node) != slot))
+		goto again;
 found:
 	rcu_read_unlock();
 	return rc;
 }
 
+/**
+ *	llc_lookup_listener - Finds listener for local MAC + SAP
+ *	@sap: SAP
+ *	@laddr: address of local LLC (MAC + SAP)
+ *
+ *	Search connection list of the SAP and finds connection listening on
+ *	local mac, and local sap. Returns pointer for parent socket found,
+ *	%NULL otherwise.
+ *	Caller has to make sure local_bh is disabled.
+ */
+static struct sock *llc_lookup_listener(struct llc_sap *sap,
+					struct llc_addr *laddr)
+{
+	static struct llc_addr null_addr;
+	struct sock *rc = __llc_lookup_listener(sap, laddr);
+
+	if (!rc)
+		rc = __llc_lookup_listener(sap, &null_addr);
+
+	return rc;
+}
+
 static struct sock *__llc_lookup(struct llc_sap *sap,
 				 struct llc_addr *daddr,
 				 struct llc_addr *laddr)
@@ -678,18 +707,20 @@ static int llc_find_offset(int state, int ev_type)
  *	@sap: SAP
  *	@sk: socket
  *
- *	This function adds a socket to sk_list of a SAP.
+ *	This function adds a socket to the hash tables of a SAP.
  */
 void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
 {
 	struct llc_sock *llc = llc_sk(sk);
 	struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex);
+	struct hlist_nulls_head *laddr_hb = llc_sk_laddr_hash(sap, &llc->laddr);
 
 	llc_sap_hold(sap);
 	llc_sk(sk)->sap = sap;
 
 	spin_lock_bh(&sap->sk_lock);
-	sk_nulls_add_node_rcu(sk, &sap->sk_list);
+	sap->sk_count++;
+	sk_nulls_add_node_rcu(sk, laddr_hb);
 	hlist_add_head(&llc->dev_hash_node, dev_hb);
 	spin_unlock_bh(&sap->sk_lock);
 }
@@ -699,7 +730,7 @@ void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
  *	@sap: SAP
  *	@sk: socket
  *
- *	This function removes a connection from sk_list of a SAP if
+ *	This function removes a connection from the hash tables of a SAP if
  *	the connection was in this list.
  */
 void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
@@ -709,6 +740,7 @@ void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
 	spin_lock_bh(&sap->sk_lock);
 	sk_nulls_del_node_init_rcu(sk);
 	hlist_del(&llc->dev_hash_node);
+	sap->sk_count--;
 	spin_unlock_bh(&sap->sk_lock);
 	llc_sap_put(sap);
 }

diff --git a/trunk/net/llc/llc_core.c b/trunk/net/llc/llc_core.c
@@ -33,12 +33,14 @@ DEFINE_RWLOCK(llc_sap_list_lock);
 static struct llc_sap *llc_sap_alloc(void)
 {
 	struct llc_sap *sap = kzalloc(sizeof(*sap), GFP_ATOMIC);
+	int i;
 
 	if (sap) {
 		/* sap->laddr.mac - leave as a null, it's filled by bind */
 		sap->state = LLC_SAP_STATE_ACTIVE;
 		spin_lock_init(&sap->sk_lock);
-		INIT_HLIST_NULLS_HEAD(&sap->sk_list, 0);
+		for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++)
+			INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i);
 		atomic_set(&sap->refcnt, 1);
 	}
 	return sap;
@@ -143,7 +145,7 @@ struct llc_sap *llc_sap_open(unsigned char lsap,
  */
 void llc_sap_close(struct llc_sap *sap)
 {
-	WARN_ON(!hlist_nulls_empty(&sap->sk_list));
+	WARN_ON(sap->sk_count);
 	llc_del_sap(sap);
 	kfree(sap);
 }

diff --git a/trunk/net/llc/llc_proc.c b/trunk/net/llc/llc_proc.c
@@ -34,17 +34,22 @@ static struct sock *llc_get_sk_idx(loff_t pos)
 {
 	struct list_head *sap_entry;
 	struct llc_sap *sap;
-	struct hlist_nulls_node *node;
 	struct sock *sk = NULL;
+	int i;
 
 	list_for_each(sap_entry, &llc_sap_list) {
 		sap = list_entry(sap_entry, struct llc_sap, node);
 
 		spin_lock_bh(&sap->sk_lock);
-		sk_nulls_for_each(sk, node, &sap->sk_list) {
-			if (!pos)
-				goto found;
-			--pos;
+		for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) {
+			struct hlist_nulls_head *head = &sap->sk_laddr_hash[i];
+			struct hlist_nulls_node *node;
+
+			sk_nulls_for_each(sk, node, head) {
+				if (!pos)
+					goto found; /* keep the lock */
+				--pos;
+			}
 		}
 		spin_unlock_bh(&sap->sk_lock);
 	}
@@ -61,6 +66,19 @@ static void *llc_seq_start(struct seq_file *seq, loff_t *pos)
 	return l ? llc_get_sk_idx(--l) : SEQ_START_TOKEN;
 }
 
+static struct sock *laddr_hash_next(struct llc_sap *sap, int bucket)
+{
+	struct hlist_nulls_node *node;
+	struct sock *sk = NULL;
+
+	while (++bucket < LLC_SK_LADDR_HASH_ENTRIES)
+		sk_nulls_for_each(sk, node, &sap->sk_laddr_hash[bucket])
+			goto out;
+
+out:
+	return sk;
+}
+
 static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct sock* sk, *next;
@@ -80,17 +98,15 @@ static void *llc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	}
 	llc = llc_sk(sk);
 	sap = llc->sap;
+	sk = laddr_hash_next(sap, llc_sk_laddr_hashfn(sap, &llc->laddr));
+	if (sk)
+		goto out;
 	spin_unlock_bh(&sap->sk_lock);
-	sk = NULL;
-	for (;;) {
-		if (sap->node.next == &llc_sap_list)
-			break;
-		sap = list_entry(sap->node.next, struct llc_sap, node);
+	list_for_each_entry_continue(sap, &llc_sap_list, node) {
 		spin_lock_bh(&sap->sk_lock);
-		if (!hlist_nulls_empty(&sap->sk_list)) {
-			sk = sk_nulls_head(&sap->sk_list);
-			break;
-		}
+		sk = laddr_hash_next(sap, -1);
+		if (sk)
+			break; /* keep the lock */
 		spin_unlock_bh(&sap->sk_lock);
 	}
 out:

diff --git a/trunk/net/llc/llc_sap.c b/trunk/net/llc/llc_sap.c
@@ -321,10 +321,12 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap,
 {
 	struct sock *rc;
 	struct hlist_nulls_node *node;
+	int slot = llc_sk_laddr_hashfn(sap, laddr);
+	struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
 
 	rcu_read_lock_bh();
 again:
-	sk_nulls_for_each_rcu(rc, node, &sap->sk_list) {
+	sk_nulls_for_each_rcu(rc, node, laddr_hb) {
 		if (llc_dgram_match(sap, laddr, rc)) {
 			/* Extra checks required by SLAB_DESTROY_BY_RCU */
 			if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
@@ -338,6 +340,13 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap,
 		}
 	}
 	rc = NULL;
+	/*
+	 * if the nulls value we got at the end of this lookup is
+	 * not the expected one, we must restart lookup.
+	 * We probably met an item that was moved to another chain.
+	 */
+	if (unlikely(get_nulls_value(node) != slot))
+		goto again;
 found:
 	rcu_read_unlock_bh();
 	return rc;