From 46651c59c483f14fd35cf7df2104feac0e54e258 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Thu, 27 Mar 2014 12:54:36 +0800 Subject: tipc: rename node create lock to protect node list and hlist When a node is created, tipc_net_lock read lock is first held and then node_create_lock is grabbed in order to prevent the same node from being created and inserted into both node list and hlist twice. But when we query node from the two node lists, we only hold tipc_net_lock read lock without grabbing node_create_lock. Obviously this locking policy is unable to guarantee that the two node lists are always synchronized especially when the operation of changing and accessing them occurs in different contexts like currently doing. Therefore, rename node_create_lock to node_list_lock to protect the two node lists, that is, whenever node is inserted into them or node is queried from them, the node_list_lock should be always held. As a result, tipc_net_lock read lock becomes redundant and then can be removed from the node query functions. Signed-off-by: Ying Xue Reviewed-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/node.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/tipc/node.h') diff --git a/net/tipc/node.h b/net/tipc/node.h index 63e2e8ead2fe..42038690c540 100644 --- a/net/tipc/node.h +++ b/net/tipc/node.h @@ -2,7 +2,7 @@ * net/tipc/node.h: Include file for TIPC node management routines * * Copyright (c) 2000-2006, Ericsson AB - * Copyright (c) 2005, 2010-2011, Wind River Systems + * Copyright (c) 2005, 2010-2014, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -107,7 +107,7 @@ extern struct list_head tipc_node_list; struct tipc_node *tipc_node_find(u32 addr); struct tipc_node *tipc_node_create(u32 addr); -void tipc_node_delete(struct tipc_node *n_ptr); +void tipc_node_stop(void); void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr); void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr); void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr); -- cgit v1.2.3 From 6c7a762e70637a256229f9dc9ca793908e8bd01b Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Thu, 27 Mar 2014 12:54:37 +0800 Subject: tipc: tipc: convert node list and node hlist to RCU lists Convert tipc_node_list list and node_htable hash list to RCU lists. On read side, the two lists are protected with RCU read lock, and on update side, node_list_lock is applied to them. Signed-off-by: Ying Xue Reviewed-by: Erik Hugne Reviewed-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/link.c | 16 ++++++++++------ net/tipc/name_distr.c | 6 +++--- net/tipc/node.c | 28 ++++++++++++++++------------ net/tipc/node.h | 2 ++ 4 files changed, 31 insertions(+), 21 deletions(-) (limited to 'net/tipc/node.h') diff --git a/net/tipc/link.c b/net/tipc/link.c index 882c5c9c52f9..c5190ab75290 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -280,13 +280,13 @@ struct tipc_link *tipc_link_create(struct tipc_node *n_ptr, return l_ptr; } - void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down) { struct tipc_link *l_ptr; struct tipc_node *n_ptr; - list_for_each_entry(n_ptr, &tipc_node_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { spin_lock_bh(&n_ptr->lock); l_ptr = n_ptr->links[bearer_id]; if (l_ptr) { @@ -309,6 +309,7 @@ void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down) } spin_unlock_bh(&n_ptr->lock); } + rcu_read_unlock(); } /** @@ -461,13 +462,15 @@ void tipc_link_reset_list(unsigned int bearer_id) struct tipc_link *l_ptr; struct tipc_node *n_ptr; - list_for_each_entry(n_ptr, &tipc_node_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { spin_lock_bh(&n_ptr->lock); l_ptr = n_ptr->links[bearer_id]; if (l_ptr) tipc_link_reset(l_ptr); spin_unlock_bh(&n_ptr->lock); } + rcu_read_unlock(); } static void link_activate(struct tipc_link *l_ptr) @@ -2404,13 +2407,12 @@ static struct tipc_node *tipc_link_find_owner(const char *link_name, { struct tipc_link *l_ptr; struct tipc_node *n_ptr; - struct tipc_node *tmp_n_ptr; struct tipc_node *found_node = 0; - int i; *bearer_id = 0; - list_for_each_entry_safe(n_ptr, tmp_n_ptr, &tipc_node_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { tipc_node_lock(n_ptr); for (i = 0; i < MAX_BEARERS; i++) { l_ptr = n_ptr->links[i]; @@ -2424,6 +2426,8 @@ static struct tipc_node *tipc_link_find_owner(const char *link_name, if (found_node) break; } + rcu_read_unlock(); + return found_node; } diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c index c5904d196cd3..aff8041dc157 100644 --- a/net/tipc/name_distr.c +++ b/net/tipc/name_distr.c @@ -133,8 +133,8 @@ static void named_cluster_distribute(struct sk_buff *buf) struct tipc_node *n_ptr; struct tipc_link *l_ptr; - read_lock_bh(&tipc_net_lock); - list_for_each_entry(n_ptr, &tipc_node_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { spin_lock_bh(&n_ptr->lock); l_ptr = n_ptr->active_links[n_ptr->addr & 1]; if (l_ptr) { @@ -148,7 +148,7 @@ static void named_cluster_distribute(struct sk_buff *buf) } spin_unlock_bh(&n_ptr->lock); } - read_unlock_bh(&tipc_net_lock); + rcu_read_unlock(); kfree_skb(buf); } diff --git a/net/tipc/node.c b/net/tipc/node.c index ec8360736239..4f517ff783d9 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -72,14 +72,14 @@ struct tipc_node *tipc_node_find(u32 addr) if (unlikely(!in_own_cluster_exact(addr))) return NULL; - spin_lock_bh(&node_list_lock); - hlist_for_each_entry(node, &node_htable[tipc_hashfn(addr)], hash) { + rcu_read_lock(); + hlist_for_each_entry_rcu(node, &node_htable[tipc_hashfn(addr)], hash) { if (node->addr == addr) { - spin_unlock_bh(&node_list_lock); + rcu_read_unlock(); return node; } } - spin_unlock_bh(&node_list_lock); + rcu_read_unlock(); return NULL; } @@ -102,13 +102,13 @@ struct tipc_node *tipc_node_create(u32 addr) INIT_LIST_HEAD(&n_ptr->list); INIT_LIST_HEAD(&n_ptr->nsub); - hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]); + hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]); - list_for_each_entry(temp_node, &tipc_node_list, list) { + list_for_each_entry_rcu(temp_node, &tipc_node_list, list) { if (n_ptr->addr < temp_node->addr) break; } - list_add_tail(&n_ptr->list, &temp_node->list); + list_add_tail_rcu(&n_ptr->list, &temp_node->list); n_ptr->block_setup = WAIT_PEER_DOWN; n_ptr->signature = INVALID_NODE_SIG; @@ -120,9 +120,9 @@ struct tipc_node *tipc_node_create(u32 addr) static void tipc_node_delete(struct tipc_node *n_ptr) { - list_del(&n_ptr->list); - hlist_del(&n_ptr->hash); - kfree(n_ptr); + list_del_rcu(&n_ptr->list); + hlist_del_rcu(&n_ptr->hash); + kfree_rcu(n_ptr, rcu); tipc_num_nodes--; } @@ -359,7 +359,8 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) } /* Add TLVs for all nodes in scope */ - list_for_each_entry(n_ptr, &tipc_node_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { if (!tipc_in_scope(domain, n_ptr->addr)) continue; node_info.addr = htonl(n_ptr->addr); @@ -367,6 +368,7 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO, &node_info, sizeof(node_info)); } + rcu_read_unlock(); spin_unlock_bh(&node_list_lock); return buf; } @@ -412,7 +414,8 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info)); /* Add TLVs for any other links in scope */ - list_for_each_entry(n_ptr, &tipc_node_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) { u32 i; if (!tipc_in_scope(domain, n_ptr->addr)) @@ -429,6 +432,7 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) } tipc_node_unlock(n_ptr); } + rcu_read_unlock(); spin_unlock_bh(&node_list_lock); return buf; } diff --git a/net/tipc/node.h b/net/tipc/node.h index 42038690c540..7cbb8cec1a93 100644 --- a/net/tipc/node.h +++ b/net/tipc/node.h @@ -66,6 +66,7 @@ * @link_cnt: number of links to node * @signature: node instance identifier * @bclink: broadcast-related info + * @rcu: rcu struct for tipc_node * @acked: sequence # of last outbound b'cast message acknowledged by node * @last_in: sequence # of last in-sequence b'cast message received from node * @last_sent: sequence # of last b'cast message sent by node @@ -89,6 +90,7 @@ struct tipc_node { int working_links; int block_setup; u32 signature; + struct rcu_head rcu; struct { u32 acked; u32 last_in; -- cgit v1.2.3