Commit ae7633c8 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'tipc-next' 



Ying Xue says:

====================
tipc: fix two corner issues

The patch set aims at resolving the following two critical issues:

Patch #1: Resolve a deadlock which happens while all links are reset
Patch #2: Correct a mistake usage of RCU lock which is used to protect
          node list
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents faadb05f 8a0f6ebe

net/tipc/bcast.c

+4 −24
Original line number Diff line number Diff line
@@ -62,21 +62,8 @@ static void tipc_bclink_lock(struct net *net) 
static void tipc_bclink_unlock(struct net *net)

{

	struct tipc_net *tn = net_generic(net, tipc_net_id);

	struct tipc_node *node = NULL;



	if (likely(!tn->bclink->flags)) {

	spin_unlock_bh(&tn->bclink->lock);

		return;

	}



	if (tn->bclink->flags & TIPC_BCLINK_RESET) {

		tn->bclink->flags &= ~TIPC_BCLINK_RESET;

		node = tipc_bclink_retransmit_to(net);

	}

	spin_unlock_bh(&tn->bclink->lock);



	if (node)

		tipc_link_reset_all(node);

}



void tipc_bclink_input(struct net *net)
@@ -91,13 +78,6 @@ uint tipc_bclink_get_mtu(void) 
	return MAX_PKT_DEFAULT_MCAST;

}



void tipc_bclink_set_flags(struct net *net, unsigned int flags)

{

	struct tipc_net *tn = net_generic(net, tipc_net_id);



	tn->bclink->flags |= flags;

}



static u32 bcbuf_acks(struct sk_buff *buf)

{

	return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
@@ -156,7 +136,6 @@ static void bclink_update_last_sent(struct tipc_node *node, u32 seqno) 
						seqno : node->bclink.last_sent;

}





/**

 * tipc_bclink_retransmit_to - get most recent node to request retransmission

 *
@@ -350,13 +329,12 @@ static void bclink_peek_nack(struct net *net, struct tipc_msg *msg) 
		return;



	tipc_node_lock(n_ptr);



	if (n_ptr->bclink.recv_permitted &&

	    (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&

	    (n_ptr->bclink.last_in == msg_bcgap_after(msg)))

		n_ptr->bclink.oos_state = 2;



	tipc_node_unlock(n_ptr);

	tipc_node_put(n_ptr);

}



/* tipc_bclink_xmit - deliver buffer chain to all nodes in cluster
@@ -476,17 +454,18 @@ void tipc_bclink_rcv(struct net *net, struct sk_buff *buf) 
			goto unlock;

		if (msg_destnode(msg) == tn->own_addr) {

			tipc_bclink_acknowledge(node, msg_bcast_ack(msg));

			tipc_node_unlock(node);

			tipc_bclink_lock(net);

			bcl->stats.recv_nacks++;

			tn->bclink->retransmit_to = node;

			bclink_retransmit_pkt(tn, msg_bcgap_after(msg),

					      msg_bcgap_to(msg));

			tipc_bclink_unlock(net);

			tipc_node_unlock(node);

		} else {

			tipc_node_unlock(node);

			bclink_peek_nack(net, msg);

		}

		tipc_node_put(node);

		goto exit;

	}
@@ -591,6 +570,7 @@ receive: 


unlock:

	tipc_node_unlock(node);

	tipc_node_put(node);

exit:

	kfree_skb(buf);

}

net/tipc/bcast.h

+0 −4
Original line number Diff line number Diff line
@@ -55,7 +55,6 @@ struct tipc_bcbearer_pair { 
	struct tipc_bearer *secondary;

};



#define TIPC_BCLINK_RESET	1

#define	BCBEARER		MAX_BEARERS



/**
@@ -86,7 +85,6 @@ struct tipc_bcbearer { 
 * @lock: spinlock governing access to structure

 * @link: (non-standard) broadcast link structure

 * @node: (non-standard) node structure representing b'cast link's peer node

 * @flags: represent bclink states

 * @bcast_nodes: map of broadcast-capable nodes

 * @retransmit_to: node that most recently requested a retransmit

 *
@@ -96,7 +94,6 @@ struct tipc_bclink { 
	spinlock_t lock;

	struct tipc_link link;

	struct tipc_node node;

	unsigned int flags;

	struct sk_buff_head arrvq;

	struct sk_buff_head inputq;

	struct tipc_node_map bcast_nodes;
@@ -117,7 +114,6 @@ static inline int tipc_nmap_equal(struct tipc_node_map *nm_a, 


int tipc_bclink_init(struct net *net);

void tipc_bclink_stop(struct net *net);

void tipc_bclink_set_flags(struct net *tn, unsigned int flags);

void tipc_bclink_add_node(struct net *net, u32 addr);

void tipc_bclink_remove_node(struct net *net, u32 addr);

struct tipc_node *tipc_bclink_retransmit_to(struct net *tn);

net/tipc/discover.c

+1 −0
Original line number Diff line number Diff line
@@ -260,6 +260,7 @@ void tipc_disc_rcv(struct net *net, struct sk_buff *buf, 
		}

	}

	tipc_node_unlock(node);

	tipc_node_put(node);

}



/**

net/tipc/link.c

+6 −6
Original line number Diff line number Diff line
@@ -854,6 +854,7 @@ int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode, 
		if (link)

			rc = __tipc_link_xmit(net, link, list);

		tipc_node_unlock(node);

		tipc_node_put(node);

	}

	if (link)

		return rc;
@@ -980,7 +981,6 @@ static void link_retransmit_failure(struct tipc_link *l_ptr, 
			(unsigned long) TIPC_SKB_CB(buf)->handle);



		n_ptr = tipc_bclink_retransmit_to(net);

		tipc_node_lock(n_ptr);



		tipc_addr_string_fill(addr_string, n_ptr->addr);

		pr_info("Broadcast link info for %s\n", addr_string);
@@ -992,9 +992,7 @@ static void link_retransmit_failure(struct tipc_link *l_ptr, 
			n_ptr->bclink.oos_state,

			n_ptr->bclink.last_sent);



		tipc_node_unlock(n_ptr);



		tipc_bclink_set_flags(net, TIPC_BCLINK_RESET);

		n_ptr->action_flags |= TIPC_BCAST_RESET;

		l_ptr->stale_count = 0;

	}

}
@@ -1119,8 +1117,8 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) 
		n_ptr = tipc_node_find(net, msg_prevnode(msg));

		if (unlikely(!n_ptr))

			goto discard;

		tipc_node_lock(n_ptr);



		tipc_node_lock(n_ptr);

		/* Locate unicast link endpoint that should handle message */

		l_ptr = n_ptr->links[b_ptr->identity];

		if (unlikely(!l_ptr))
@@ -1208,6 +1206,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) 
		skb = NULL;

unlock:

		tipc_node_unlock(n_ptr);

		tipc_node_put(n_ptr);

discard:

		if (unlikely(skb))

			kfree_skb(skb);
@@ -2239,7 +2238,6 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb) 
	msg.seq = cb->nlh->nlmsg_seq;



	rcu_read_lock();



	if (prev_node) {

		node = tipc_node_find(net, prev_node);

		if (!node) {
@@ -2252,6 +2250,7 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb) 
			cb->prev_seq = 1;

			goto out;

		}

		tipc_node_put(node);



		list_for_each_entry_continue_rcu(node, &tn->node_list,

						 list) {
@@ -2259,6 +2258,7 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb) 
			err = __tipc_nl_add_node_links(net, &msg, node,

						       &prev_link);

			tipc_node_unlock(node);

			tipc_node_put(node);

			if (err)

				goto out;

net/tipc/name_distr.c

+2 −0
Original line number Diff line number Diff line
@@ -244,6 +244,7 @@ static void tipc_publ_subscribe(struct net *net, struct publication *publ, 
	tipc_node_lock(node);

	list_add_tail(&publ->nodesub_list, &node->publ_list);

	tipc_node_unlock(node);

	tipc_node_put(node);

}



static void tipc_publ_unsubscribe(struct net *net, struct publication *publ,
@@ -258,6 +259,7 @@ static void tipc_publ_unsubscribe(struct net *net, struct publication *publ, 
	tipc_node_lock(node);

	list_del_init(&publ->nodesub_list);

	tipc_node_unlock(node);

	tipc_node_put(node);

}



/**

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