From 6a939f365bdb03a74b4617bdb4402fc08da088b9 Mon Sep 17 00:00:00 2001 From: GhantaKrishnamurthy MohanKrishna Date: Fri, 29 Jun 2018 13:23:41 +0200 Subject: [PATCH] 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: Ying Xue Acked-by: Jon Maloy Signed-off-by: GhantaKrishnamurthy MohanKrishna Signed-off-by: David S. Miller --- net/tipc/node.c | 66 ++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 55 insertions(+), 11 deletions(-) diff --git a/net/tipc/node.c b/net/tipc/node.c index 8972ca1c654c..cfdbaf479fd1 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -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);