Commit 6a939f36 authored by GhantaKrishnamurthy MohanKrishna's avatar GhantaKrishnamurthy MohanKrishna Committed by David S. Miller
Browse files

tipc: Auto removal of peer down node instance 



A peer node is considered down if there are no
active links (or) lost contact to the node. In current implementation,
a peer node instance is deleted either if

a) TIPC module is removed (or)
b) Application can use a netlink/iproute2 interface to delete a
specific down node.

Thus, a down node instance lives in the system forever, unless the
application explicitly removes it.

We fix this by deleting the nodes which are down for
a specified amount of time (5 minutes).
Existing node supervision timer is used to achieve this.

Acked-by: default avatarYing Xue <ying.xue@windriver.com>
Acked-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: default avatarGhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e397286b

net/tipc/node.c

+55 −11
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#include "netlink.h"



#define INVALID_NODE_SIG	0x10000

#define NODE_CLEANUP_AFTER	300000



/* Flags used to take different actions according to flag type

 * TIPC_NOTIFY_NODE_DOWN: notify node is down
@@ -96,6 +97,7 @@ struct tipc_bclink_entry { 
 * @link_id: local and remote bearer ids of changing link, if any

 * @publ_list: list of publications

 * @rcu: rcu struct for tipc_node

 * @delete_at: indicates the time for deleting a down node

 */

struct tipc_node {

	u32 addr;
@@ -121,6 +123,7 @@ struct tipc_node { 
	unsigned long keepalive_intv;

	struct timer_list timer;

	struct rcu_head rcu;

	unsigned long delete_at;

};



/* Node FSM states and events:
@@ -160,6 +163,7 @@ static struct tipc_node *tipc_node_find(struct net *net, u32 addr); 
static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);

static void tipc_node_put(struct tipc_node *node);

static bool node_is_up(struct tipc_node *n);

static void tipc_node_delete_from_list(struct tipc_node *node);



struct tipc_sock_conn {

	u32 port;
@@ -390,6 +394,7 @@ static struct tipc_node *tipc_node_create(struct net *net, u32 addr, 
	for (i = 0; i < MAX_BEARERS; i++)

		spin_lock_init(&n->links[i].lock);

	n->state = SELF_DOWN_PEER_LEAVING;

	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);

	n->signature = INVALID_NODE_SIG;

	n->active_links[0] = INVALID_BEARER_ID;

	n->active_links[1] = INVALID_BEARER_ID;
@@ -433,11 +438,16 @@ static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l) 
	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);

}



static void tipc_node_delete(struct tipc_node *node)

static void tipc_node_delete_from_list(struct tipc_node *node)

{

	list_del_rcu(&node->list);

	hlist_del_rcu(&node->hash);

	tipc_node_put(node);

}



static void tipc_node_delete(struct tipc_node *node)

{

	tipc_node_delete_from_list(node);



	del_timer_sync(&node->timer);

	tipc_node_put(node);
@@ -544,6 +554,42 @@ void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port) 
	tipc_node_put(node);

}



static void  tipc_node_clear_links(struct tipc_node *node)

{

	int i;



	for (i = 0; i < MAX_BEARERS; i++) {

		struct tipc_link_entry *le = &node->links[i];



		if (le->link) {

			kfree(le->link);

			le->link = NULL;

			node->link_cnt--;

		}

	}

}



/* tipc_node_cleanup - delete nodes that does not

 * have active links for NODE_CLEANUP_AFTER time

 */

static int tipc_node_cleanup(struct tipc_node *peer)

{

	struct tipc_net *tn = tipc_net(peer->net);

	bool deleted = false;



	spin_lock_bh(&tn->node_list_lock);

	tipc_node_write_lock(peer);



	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {

		tipc_node_clear_links(peer);

		tipc_node_delete_from_list(peer);

		deleted = true;

	}

	tipc_node_write_unlock(peer);

	spin_unlock_bh(&tn->node_list_lock);

	return deleted;

}



/* tipc_node_timeout - handle expiration of node timer

 */

static void tipc_node_timeout(struct timer_list *t)
@@ -555,6 +601,12 @@ static void tipc_node_timeout(struct timer_list *t) 
	int bearer_id;

	int rc = 0;



	if (!node_is_up(n) && tipc_node_cleanup(n)) {

		/*Removing the reference of Timer*/

		tipc_node_put(n);

		return;

	}



	__skb_queue_head_init(&xmitq);



	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
@@ -1173,6 +1225,7 @@ static void node_lost_contact(struct tipc_node *n, 
	uint i;



	pr_debug("Lost contact with %x\n", n->addr);

	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);



	/* Clean up broadcast state */

	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
@@ -1742,7 +1795,6 @@ int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info) 
	struct tipc_node *peer;

	u32 addr;

	int err;

	int i;



	/* We identify the peer by its net */

	if (!info->attrs[TIPC_NLA_NET])
@@ -1777,15 +1829,7 @@ int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info) 
		goto err_out;

	}



	for (i = 0; i < MAX_BEARERS; i++) {

		struct tipc_link_entry *le = &peer->links[i];



		if (le->link) {

			kfree(le->link);

			le->link = NULL;

			peer->link_cnt--;

		}

	}

	tipc_node_clear_links(peer);

	tipc_node_write_unlock(peer);

	tipc_node_delete(peer);

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