[LLC] use struct sock list members

Now that we don't have anymore the double sock (PF_LLC + core) we can
use struct sock list members.

Also use use rw locks instead of spinlocks in some places.

include/net/llc_main.h

@@ -43,7 +43,7 @@ struct llc_station {
 	u8			    maximum_retry;
 	u8			    mac_sa[6];
 	struct {
-		spinlock_t	    lock;
+		rwlock_t	    lock;
 		struct list_head    list;
 	} sap_list;
 	struct {

include/net/llc_sap.h

@@ -16,30 +16,30 @@
 /**
  * struct llc_sap - Defines the SAP component
  *
+ * @station - station this sap belongs to
+ * @state - sap state
  * @p_bit - only lowest-order bit used
  * @f_bit - only lowest-order bit used
- * @ind - provided by network layer
- * @conf - provided by network layer
  * @laddr - SAP value in this 'lsap'
  * @node - entry in station sap_list
  * @sk_list - LLC sockets this one manages
  * @mac_pdu_q - PDUs ready to send to MAC
  */
 struct llc_sap {
-	struct llc_station	 *parent_station;
-	u8			 state;
-	u8			 p_bit;
-	u8			 f_bit;
-	int			 (*rcv_func)(struct sk_buff *skb,
-					     struct net_device *dev,
-					     struct packet_type *pt);
-	struct llc_addr		 laddr;
-	struct list_head	 node;
+	struct llc_station *station;
+	u8		    state;
+	u8		    p_bit;
+	u8		    f_bit;
+	int		    (*rcv_func)(struct sk_buff *skb,
+					struct net_device *dev,
+					struct packet_type *pt);
+	struct llc_addr	    laddr;
+	struct list_head    node;
 	struct {
-		spinlock_t	 lock;
-		struct list_head list;
+		rwlock_t    lock;
+		struct sock *list;
 	} sk_list;
-	struct sk_buff_head	 mac_pdu_q;
+	struct sk_buff_head mac_pdu_q;
 };
 struct llc_sap_state_ev;
 

net/llc/llc_conn.c

@@ -493,27 +493,21 @@ static int llc_exec_conn_trans_actions(struct sock *sk,
 struct sock *llc_lookup_established(struct llc_sap *sap, struct llc_addr *daddr,
 				    struct llc_addr *laddr)
 {
-	struct sock *rc = NULL;
-	struct list_head *entry;
+	struct sock *rc;
 
-	spin_lock_bh(&sap->sk_list.lock);
-	if (list_empty(&sap->sk_list.list))
-		goto out;
-	list_for_each(entry, &sap->sk_list.list) {
-		struct llc_opt *llc = list_entry(entry, struct llc_opt, node);
+	read_lock_bh(&sap->sk_list.lock);
+	for (rc = sap->sk_list.list; rc; rc = rc->next) {
+		struct llc_opt *llc = llc_sk(rc);
 
 		if (llc->laddr.lsap == laddr->lsap &&
 		    llc->daddr.lsap == daddr->lsap &&
 		    llc_mac_match(llc->laddr.mac, laddr->mac) &&
-		    llc_mac_match(llc->daddr.mac, daddr->mac)) {
-			rc = llc->sk;
+		    llc_mac_match(llc->daddr.mac, daddr->mac))
 			break;
-		}
 	}
 	if (rc)
 		sock_hold(rc);
-out:
-	spin_unlock_bh(&sap->sk_list.lock);
+	read_unlock_bh(&sap->sk_list.lock);
 	return rc;
 }
 
@@ -528,25 +522,20 @@ struct sock *llc_lookup_established(struct llc_sap *sap, struct llc_addr *daddr,
  */
 struct sock *llc_lookup_listener(struct llc_sap *sap, struct llc_addr *laddr)
 {
-	struct sock *rc = NULL;
-	struct list_head *entry;
+	struct sock *rc;
 
-	spin_lock_bh(&sap->sk_list.lock);
-	if (list_empty(&sap->sk_list.list))
-		goto out;
-	list_for_each(entry, &sap->sk_list.list) {
-		struct llc_opt *llc = list_entry(entry, struct llc_opt, node);
-
-		if (llc->sk->type != SOCK_STREAM || llc->sk->state != TCP_LISTEN ||
-		    llc->laddr.lsap != laddr->lsap ||
-		    !llc_mac_match(llc->laddr.mac, laddr->mac))
-			continue;
-		rc = llc->sk;
+	read_lock_bh(&sap->sk_list.lock);
+	for (rc = sap->sk_list.list; rc; rc = rc->next) {
+		struct llc_opt *llc = llc_sk(rc);
+
+		if (rc->type == SOCK_STREAM && rc->state == TCP_LISTEN &&
+		    llc->laddr.lsap == laddr->lsap &&
+		    llc_mac_match(llc->laddr.mac, laddr->mac))
+			break;
 	}
 	if (rc)
 		sock_hold(rc);
-out:
-	spin_unlock_bh(&sap->sk_list.lock);
+	read_unlock_bh(&sap->sk_list.lock);
 	return rc;
 }
 
@@ -560,26 +549,20 @@ struct sock *llc_lookup_listener(struct llc_sap *sap, struct llc_addr *laddr)
  */
 struct sock *llc_lookup_dgram(struct llc_sap *sap, struct llc_addr *laddr)
 {
-	struct sock *rc = NULL;
-	struct list_head *entry;
+	struct sock *rc;
 
-	spin_lock_bh(&sap->sk_list.lock);
-	if (list_empty(&sap->sk_list.list))
-		goto out;
-	list_for_each(entry, &sap->sk_list.list) {
-		struct llc_opt *llc = list_entry(entry, struct llc_opt, node);
+	read_lock_bh(&sap->sk_list.lock);
+	for (rc = sap->sk_list.list; rc; rc = rc->next) {
+		struct llc_opt *llc = llc_sk(rc);
 
-		if (llc->sk->type == SOCK_DGRAM &&
+		if (rc->type == SOCK_DGRAM &&
 		    llc->laddr.lsap == laddr->lsap &&
-		    llc_mac_match(llc->laddr.mac, laddr->mac)) {
-			rc = llc->sk;
+		    llc_mac_match(llc->laddr.mac, laddr->mac))
 			break;
-		}
 	}
 	if (rc)
 		sock_hold(rc);
-out:
-	spin_unlock_bh(&sap->sk_list.lock);
+	read_unlock_bh(&sap->sk_list.lock);
 	return rc;
 }
 /**

net/llc/llc_if.c

@@ -56,8 +56,8 @@ struct llc_sap *llc_sap_open(u8 lsap, int (*func)(struct sk_buff *skb,
 		goto err;
 	/* allocated a SAP; initialize it and clear out its memory pool */
 	sap->laddr.lsap = lsap;
-	sap->rcv_func = func;
-	sap->parent_station = llc_station_get();
+	sap->rcv_func	= func;
+	sap->station	= llc_station_get();
 	/* initialized SAP; add it to list of SAPs this station manages */
 	llc_sap_save(sap);
 out:

net/llc/llc_main.c

@@ -71,7 +71,6 @@ struct llc_sap *llc_sap_alloc(void)
 		sap->state = LLC_SAP_STATE_ACTIVE;
 		memcpy(sap->laddr.mac, llc_main_station.mac_sa, ETH_ALEN);
 		spin_lock_init(&sap->sk_list.lock);
-		INIT_LIST_HEAD(&sap->sk_list.list);
 		skb_queue_head_init(&sap->mac_pdu_q);
 	}
 	return sap;
@@ -86,12 +85,10 @@ struct llc_sap *llc_sap_alloc(void)
  */
 void llc_free_sap(struct llc_sap *sap)
 {
-	struct llc_station *station = sap->parent_station;
-
 	llc_rtn_all_conns(sap);
-	spin_lock_bh(&station->sap_list.lock);
+	write_lock_bh(&sap->station->sap_list.lock);
 	list_del(&sap->node);
-	spin_unlock_bh(&station->sap_list.lock);
+	write_unlock_bh(&sap->station->sap_list.lock);
 	kfree(sap);
 }
 
@@ -103,9 +100,9 @@ void llc_free_sap(struct llc_sap *sap)
  */
 void llc_sap_save(struct llc_sap *sap)
 {
-	spin_lock_bh(&llc_main_station.sap_list.lock);
+	write_lock_bh(&llc_main_station.sap_list.lock);
 	list_add_tail(&sap->node, &llc_main_station.sap_list.list);
-	spin_unlock_bh(&llc_main_station.sap_list.lock);
+	write_unlock_bh(&llc_main_station.sap_list.lock);
 }
 
 /**
@@ -120,7 +117,7 @@ struct llc_sap *llc_sap_find(u8 sap_value)
 	struct llc_sap* sap = NULL;
 	struct list_head *entry;
 
-	spin_lock_bh(&llc_main_station.sap_list.lock);
+	read_lock_bh(&llc_main_station.sap_list.lock);
 	list_for_each(entry, &llc_main_station.sap_list.list) {
 		sap = list_entry(entry, struct llc_sap, node);
 		if (sap->laddr.lsap == sap_value)
@@ -128,7 +125,7 @@ struct llc_sap *llc_sap_find(u8 sap_value)
 	}
 	if (entry == &llc_main_station.sap_list.list) /* not found */
 		sap = NULL;
-	spin_unlock_bh(&llc_main_station.sap_list.lock);
+	read_unlock_bh(&llc_main_station.sap_list.lock);
 	return sap;
 }
 
@@ -326,20 +323,18 @@ void llc_sk_reset(struct sock *sk)
 static int llc_rtn_all_conns(struct llc_sap *sap)
 {
 	int rc = 0;
-	struct list_head *entry, *tmp;
+	struct sock *sk;
 
-	spin_lock_bh(&sap->sk_list.lock);
-	if (list_empty(&sap->sk_list.list))
-		goto out;
-	list_for_each_safe(entry, tmp, &sap->sk_list.list) {
-		struct llc_opt *llc = list_entry(entry, struct llc_opt, node);
+	write_lock_bh(&sap->sk_list.lock);
+
+	for (sk = sap->sk_list.list; sk; sk = sk->next) {
+		llc_sk(sk)->state = LLC_CONN_STATE_TEMP;
 
-		llc->state = LLC_CONN_STATE_TEMP;
-		if (llc_send_disc(llc->sk))
+		if (llc_send_disc(sk))
 			rc = 1;
 	}
-out:
-	spin_unlock_bh(&sap->sk_list.lock);
+
+	write_unlock_bh(&sap->sk_list.lock);
 	return rc;
 }
 
@@ -562,19 +557,19 @@ static char *llc_conn_state_names[] = {
 
 static int llc_proc_get_info(char *bf, char **start, off_t offset, int length)
 {
-	struct llc_opt *llc;
-	struct list_head *sap_entry, *llc_entry;
+	struct list_head *sap_entry;
+	struct sock *sk;
 	off_t begin = 0, pos = 0;
 	int len = 0;
 
-	spin_lock_bh(&llc_main_station.sap_list.lock);
+	read_lock_bh(&llc_main_station.sap_list.lock);
 	list_for_each(sap_entry, &llc_main_station.sap_list.list) {
 		struct llc_sap *sap = list_entry(sap_entry, struct llc_sap,
 						 node);
 
 		len += sprintf(bf + len, "lsap=%02X\n", sap->laddr.lsap);
-		spin_lock_bh(&sap->sk_list.lock);
-		if (list_empty(&sap->sk_list.list)) {
+		read_lock_bh(&sap->sk_list.lock);
+		if (!sap->sk_list.list) {
 			len += sprintf(bf + len, "no connections\n");
 			goto unlock;
 		}
@@ -582,8 +577,9 @@ static int llc_proc_get_info(char *bf, char **start, off_t offset, int length)
 					 "dsap state      retr txw rxw "
 					 "pf ff sf df rs cs "
 					 "tack tpfc trs tbs blog busr\n");
-		list_for_each(llc_entry, &sap->sk_list.list) {
-			llc = list_entry(llc_entry, struct llc_opt, node);
+		for (sk = sap->sk_list.list; sk; sk = sk->next) {
+			struct llc_opt *llc = llc_sk(sk);
+
 			len += sprintf(bf + len, " %02X  %-10s %3d  %3d %3d "
 						 "%2d %2d %2d "
 						 "%2d %2d %2d "
@@ -598,11 +594,10 @@ static int llc_proc_get_info(char *bf, char **start, off_t offset, int length)
 				       timer_pending(&llc->pf_cycle_timer.timer),
 				       timer_pending(&llc->rej_sent_timer.timer),
 				       timer_pending(&llc->busy_state_timer.timer),
-				       !!llc->sk->backlog.tail,
-				       llc->sk->lock.users);
+				       !!sk->backlog.tail, sk->lock.users);
 		}
 unlock:	
-		spin_unlock_bh(&sap->sk_list.lock);
+		read_unlock_bh(&sap->sk_list.lock);
 		pos = begin + len;
 		if (pos < offset) {
 			len = 0; /* Keep dumping into the buffer start */
@@ -611,7 +606,7 @@ static int llc_proc_get_info(char *bf, char **start, off_t offset, int length)
 		if (pos > offset + length) /* We have dumped enough */
 			break;
 	}
-	spin_unlock_bh(&llc_main_station.sap_list.lock);
+	read_unlock_bh(&llc_main_station.sap_list.lock);
 
 	/* The data in question runs from begin to begin + len */
 	*start = bf + (offset - begin); /* Start of wanted data */
@@ -632,8 +627,8 @@ static struct packet_type llc_tr_packet_type = {
 };
 
 static char llc_banner[] __initdata =
-		KERN_INFO "LLC 2.0 by Procom, 1997, Arnaldo C. Melo, 2001\n"
-		KERN_INFO "NET4.0 IEEE 802.2 extended support\n";
+		KERN_INFO "LLC 2.0 by Procom, 1997, Arnaldo C. Melo, 2001, 2002\n"
+		KERN_INFO "NET 4.0 IEEE 802.2 extended support\n";
 static char llc_error_msg[] __initdata =
 		KERN_ERR "LLC install NOT successful.\n";
 
@@ -693,5 +688,5 @@ module_init(llc_init);
 module_exit(llc_exit);
 
 MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Procom, 1997, Arnaldo C. Melo, Jay Schullist, 2001");
+MODULE_AUTHOR("Procom, 1997, Arnaldo C. Melo, Jay Schullist, 2001, 2002");
 MODULE_DESCRIPTION("LLC 2.0, NET4.0 IEEE 802.2 extended support");

net/llc/llc_sap.c

@@ -40,11 +40,15 @@ static struct llc_sap_state_trans *llc_find_sap_trans(struct llc_sap *sap,
  */
 void llc_sap_assign_sock(struct llc_sap *sap, struct sock *sk)
 {
-	spin_lock_bh(&sap->sk_list.lock);
+	write_lock_bh(&sap->sk_list.lock);
 	llc_sk(sk)->sap = sap;
-	list_add_tail(&llc_sk(sk)->node, &sap->sk_list.list);
+	sk->next = sap->sk_list.list;
+	if (sk->next)
+		sap->sk_list.list->pprev = &sk->next;
+	sap->sk_list.list = sk;
+	sk->pprev = &sap->sk_list.list;
 	sock_hold(sk);
-	spin_unlock_bh(&sap->sk_list.lock);
+	write_unlock_bh(&sap->sk_list.lock);
 }
 
 /**
@@ -56,10 +60,19 @@ void llc_sap_assign_sock(struct llc_sap *sap, struct sock *sk)
  */
 void llc_sap_unassign_sock(struct llc_sap *sap, struct sock *sk)
 {
-	spin_lock_bh(&sap->sk_list.lock);
-	list_del(&llc_sk(sk)->node);
-	sock_put(sk);
-	spin_unlock_bh(&sap->sk_list.lock);
+	write_lock_bh(&sap->sk_list.lock);
+	if (sk->pprev) {
+		if (sk->next)
+			sk->next->pprev = sk->pprev;
+		*sk->pprev = sk->next;
+		sk->pprev  = NULL;
+		/*
+		 * This only makes sense if the socket was inserted on the
+		 * list, if sk->pprev is NULL it wasn't
+		 */
+		sock_put(sk);
+	}
+	write_unlock_bh(&sap->sk_list.lock);
 }
 
 /**

net/llc/llc_sock.c

@@ -198,7 +198,7 @@ static int llc_ui_release(struct socket *sock)
 	if (!sk->zapped)
 		llc_sap_unassign_sock(llc->sap, sk);
 	release_sock(sk);
-	if (llc->sap && list_empty(&llc->sap->sk_list.list))
+	if (llc->sap && !llc->sap->sk_list.list)
 		llc_sap_close(llc->sap);
 	sock_put(sk);
 	llc_sk_free(sk);
@@ -1042,25 +1042,24 @@ static int llc_ui_get_info(char *buffer, char **start, off_t offset, int length)
 {
 	off_t pos = 0;
 	off_t begin = 0;
-	struct llc_opt *llc;
 	struct llc_sap *sap;
-	struct list_head *sap_entry, *llc_entry;
+	struct sock *sk;
+	struct list_head *sap_entry;
 	struct llc_station *station = llc_station_get();
 	int len = sprintf(buffer, "SKt Mc local_mac_sap        "
 				  "remote_mac_sap       tx_queue rx_queue st uid "
 				  "link\n");
 
 	/* Output the LLC socket data for the /proc filesystem */
-	spin_lock_bh(&station->sap_list.lock);
+	read_lock_bh(&station->sap_list.lock);
 	list_for_each(sap_entry, &station->sap_list.list) {
 		sap = list_entry(sap_entry, struct llc_sap, node);
 
-		spin_lock_bh(&sap->sk_list.lock);
-		list_for_each(llc_entry, &sap->sk_list.list) {
-			llc = list_entry(llc_entry, struct llc_opt, node);
+		read_lock_bh(&sap->sk_list.lock);
+		for (sk = sap->sk_list.list; sk; sk = sk->next) {
+			struct llc_opt *llc = llc_sk(sk);
 
-			len += sprintf(buffer + len, "%2X  %2X ",
-				       llc->sk->type,
+			len += sprintf(buffer + len, "%2X  %2X ", sk->type,
 				       !llc_mac_null(llc->addr.sllc_mmac));
 			if (llc->dev && llc_mac_null(llc->addr.sllc_mmac))
 				llc_ui_format_mac(buffer + len,
@@ -1080,12 +1079,11 @@ static int llc_ui_get_info(char *buffer, char **start, off_t offset, int length)
 			len += sprintf(buffer + len,
 					"@%02X %8d %8d %2d %3d ",
 					llc->addr.sllc_dsap,
-					atomic_read(&llc->sk->wmem_alloc),
-					atomic_read(&llc->sk->rmem_alloc),
-					llc->sk->state,
-					llc->sk->socket ?
-					  SOCK_INODE(llc->sk->socket)->i_uid :
-					  -1);
+					atomic_read(&sk->wmem_alloc),
+					atomic_read(&sk->rmem_alloc),
+					sk->state,
+					sk->socket ?
+					  SOCK_INODE(sk->socket)->i_uid : -1);
 			len += sprintf(buffer + len, "%4d\n", llc->link);
 			/* Are we still dumping unwanted data then discard the record */
 			pos = begin + len;
@@ -1097,9 +1095,9 @@ static int llc_ui_get_info(char *buffer, char **start, off_t offset, int length)
 			if (pos > offset + length) /* We have dumped enough */
 				break;
 		}
-		spin_unlock_bh(&sap->sk_list.lock);
+		read_unlock_bh(&sap->sk_list.lock);
 	}
-	spin_unlock_bh(&station->sap_list.lock);
+	read_unlock_bh(&station->sap_list.lock);
 
 	/* The data in question runs from begin to begin + len */
 	*start = buffer + offset - begin; /* Start of wanted data */