diff options
| -rw-r--r-- | net/tipc/node.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/net/tipc/node.c b/net/tipc/node.c index 598f4d3a0098..34e9a2bb7c19 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -52,16 +52,40 @@ static void node_established_contact(struct node *n_ptr); struct node *tipc_nodes = NULL; /* sorted list of nodes within cluster */ +static DEFINE_SPINLOCK(node_create_lock); + u32 tipc_own_tag = 0; +/** + * tipc_node_create - create neighboring node + * + * Currently, this routine is called by neighbor discovery code, which holds + * net_lock for reading only. We must take node_create_lock to ensure a node + * isn't created twice if two different bearers discover the node at the same + * time. (It would be preferable to switch to holding net_lock in write mode, + * but this is a non-trivial change.) + */ + struct node *tipc_node_create(u32 addr) { struct cluster *c_ptr; struct node *n_ptr; struct node **curr_node; + spin_lock_bh(&node_create_lock); + + for (n_ptr = tipc_nodes; n_ptr; n_ptr = n_ptr->next) { + if (addr < n_ptr->addr) + break; + if (addr == n_ptr->addr) { + spin_unlock_bh(&node_create_lock); + return n_ptr; + } + } + n_ptr = kzalloc(sizeof(*n_ptr),GFP_ATOMIC); if (!n_ptr) { + spin_unlock_bh(&node_create_lock); warn("Node creation failed, no memory\n"); return NULL; } @@ -71,6 +95,7 @@ struct node *tipc_node_create(u32 addr) c_ptr = tipc_cltr_create(addr); } if (!c_ptr) { + spin_unlock_bh(&node_create_lock); kfree(n_ptr); return NULL; } @@ -91,6 +116,7 @@ struct node *tipc_node_create(u32 addr) } } (*curr_node) = n_ptr; + spin_unlock_bh(&node_create_lock); return n_ptr; } |