1 files changed, 80 insertions, 35 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 598f4d3a0098..20d98c56e152 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -46,22 +46,46 @@
 #include "bearer.h"
 #include "name_distr.h"
 
-void node_print(struct print_buf *buf, struct node *n_ptr, char *str);
-static void node_lost_contact(struct node *n_ptr);
-static void node_established_contact(struct node *n_ptr);
+void node_print(struct print_buf *buf, struct tipc_node *n_ptr, char *str);
+static void node_lost_contact(struct tipc_node *n_ptr);
+static void node_established_contact(struct tipc_node *n_ptr);
 
-struct node *tipc_nodes = NULL; /* sorted list of nodes within cluster */
+struct tipc_node *tipc_nodes = NULL;    /* sorted list of nodes within cluster */
+
+static DEFINE_SPINLOCK(node_create_lock);
 
 u32 tipc_own_tag = 0;
 
-struct node *tipc_node_create(u32 addr)
+/**
+ * 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 tipc_node *tipc_node_create(u32 addr)
 {
         struct cluster *c_ptr;
-        struct node *n_ptr;
-        struct node **curr_node;
+        struct tipc_node *n_ptr;
+        struct tipc_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;
         }
@@ -91,10 +116,11 @@ struct node *tipc_node_create(u32 addr)
                 }
         }
         (*curr_node) = n_ptr;
+        spin_unlock_bh(&node_create_lock);
         return n_ptr;
 }
 
-void tipc_node_delete(struct node *n_ptr)
+void tipc_node_delete(struct tipc_node *n_ptr)
 {
         if (!n_ptr)
                 return;
@@ -120,7 +146,7 @@ void tipc_node_delete(struct node *n_ptr)
  * Link becomes active (alone or shared) or standby, depending on its priority.
  */
 
-void tipc_node_link_up(struct node *n_ptr, struct link *l_ptr)
+void tipc_node_link_up(struct tipc_node *n_ptr, struct link *l_ptr)
 {
         struct link **active = &n_ptr->active_links[0];
 
@@ -154,7 +180,7 @@ void tipc_node_link_up(struct node *n_ptr, struct link *l_ptr)
  * node_select_active_links - select active link
  */
 
-static void node_select_active_links(struct node *n_ptr)
+static void node_select_active_links(struct tipc_node *n_ptr)
 {
         struct link **active = &n_ptr->active_links[0];
         u32 i;
@@ -182,7 +208,7 @@ static void node_select_active_links(struct node *n_ptr)
  * tipc_node_link_down - handle loss of link
  */
 
-void tipc_node_link_down(struct node *n_ptr, struct link *l_ptr)
+void tipc_node_link_down(struct tipc_node *n_ptr, struct link *l_ptr)
 {
         struct link **active;
 
@@ -209,30 +235,30 @@ void tipc_node_link_down(struct node *n_ptr, struct link *l_ptr)
                 node_lost_contact(n_ptr);
 }
 
-int tipc_node_has_active_links(struct node *n_ptr)
+int tipc_node_has_active_links(struct tipc_node *n_ptr)
 {
         return (n_ptr &&
                 ((n_ptr->active_links[0]) || (n_ptr->active_links[1])));
 }
 
-int tipc_node_has_redundant_links(struct node *n_ptr)
+int tipc_node_has_redundant_links(struct tipc_node *n_ptr)
 {
         return (n_ptr->working_links > 1);
 }
 
-static int tipc_node_has_active_routes(struct node *n_ptr)
+static int tipc_node_has_active_routes(struct tipc_node *n_ptr)
 {
         return (n_ptr && (n_ptr->last_router >= 0));
 }
 
-int tipc_node_is_up(struct node *n_ptr)
+int tipc_node_is_up(struct tipc_node *n_ptr)
 {
         return (tipc_node_has_active_links(n_ptr) || tipc_node_has_active_routes(n_ptr));
 }
 
-struct node *tipc_node_attach_link(struct link *l_ptr)
+struct tipc_node *tipc_node_attach_link(struct link *l_ptr)
 {
-        struct node *n_ptr = tipc_node_find(l_ptr->addr);
+        struct tipc_node *n_ptr = tipc_node_find(l_ptr->addr);
 
         if (!n_ptr)
                 n_ptr = tipc_node_create(l_ptr->addr);
@@ -259,7 +285,7 @@ struct node *tipc_node_attach_link(struct link *l_ptr)
         return NULL;
 }
 
-void tipc_node_detach_link(struct node *n_ptr, struct link *l_ptr)
+void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr)
 {
         n_ptr->links[l_ptr->b_ptr->identity] = NULL;
         tipc_net.zones[tipc_zone(l_ptr->addr)]->links--;
@@ -312,7 +338,7 @@ void tipc_node_detach_link(struct node *n_ptr, struct link *l_ptr)
  *
  */
 
-static void node_established_contact(struct node *n_ptr)
+static void node_established_contact(struct tipc_node *n_ptr)
 {
         struct cluster *c_ptr;
 
@@ -358,10 +384,10 @@ static void node_established_contact(struct node *n_ptr)
                                   tipc_highest_allowed_slave);
 }
 
-static void node_lost_contact(struct node *n_ptr)
+static void node_lost_contact(struct tipc_node *n_ptr)
 {
         struct cluster *c_ptr;
-        struct node_subscr *ns, *tns;
+        struct tipc_node_subscr *ns, *tns;
         char addr_string[16];
         u32 i;
 
@@ -440,9 +466,9 @@ static void node_lost_contact(struct node *n_ptr)
  * Called by when cluster local lookup has failed.
  */
 
-struct node *tipc_node_select_next_hop(u32 addr, u32 selector)
+struct tipc_node *tipc_node_select_next_hop(u32 addr, u32 selector)
 {
-        struct node *n_ptr;
+        struct tipc_node *n_ptr;
         u32 router_addr;
 
         if (!tipc_addr_domain_valid(addr))
@@ -487,7 +513,7 @@ struct node *tipc_node_select_next_hop(u32 addr, u32 selector)
  * Uses a deterministic and fair algorithm for selecting router node.
  */
 
-u32 tipc_node_select_router(struct node *n_ptr, u32 ref)
+u32 tipc_node_select_router(struct tipc_node *n_ptr, u32 ref)
 {
         u32 ulim;
         u32 mask;
@@ -525,7 +551,7 @@ u32 tipc_node_select_router(struct node *n_ptr, u32 ref)
         return tipc_addr(own_zone(), own_cluster(), r);
 }
 
-void tipc_node_add_router(struct node *n_ptr, u32 router)
+void tipc_node_add_router(struct tipc_node *n_ptr, u32 router)
 {
         u32 r_num = tipc_node(router);
 
@@ -536,7 +562,7 @@ void tipc_node_add_router(struct node *n_ptr, u32 router)
                !n_ptr->routers[n_ptr->last_router]);
 }
 
-void tipc_node_remove_router(struct node *n_ptr, u32 router)
+void tipc_node_remove_router(struct tipc_node *n_ptr, u32 router)
 {
         u32 r_num = tipc_node(router);
 
@@ -554,7 +580,7 @@ void tipc_node_remove_router(struct node *n_ptr, u32 router)
 }
 
 #if 0
-void node_print(struct print_buf *buf, struct node *n_ptr, char *str)
+void node_print(struct print_buf *buf, struct tipc_node *n_ptr, char *str)
 {
         u32 i;
 
@@ -571,15 +597,17 @@ void node_print(struct print_buf *buf, struct node *n_ptr, char *str)
 
 u32 tipc_available_nodes(const u32 domain)
 {
-        struct node *n_ptr;
+        struct tipc_node *n_ptr;
         u32 cnt = 0;
 
+        read_lock_bh(&tipc_net_lock);
         for (n_ptr = tipc_nodes; n_ptr; n_ptr = n_ptr->next) {
                 if (!in_scope(domain, n_ptr->addr))
                         continue;
                 if (tipc_node_is_up(n_ptr))
                         cnt++;
         }
+        read_unlock_bh(&tipc_net_lock);
         return cnt;
 }
 
@@ -587,7 +615,7 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
 {
         u32 domain;
         struct sk_buff *buf;
-        struct node *n_ptr;
+        struct tipc_node *n_ptr;
         struct tipc_node_info node_info;
         u32 payload_size;
 
@@ -599,19 +627,26 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                                                    " (network address)");
 
-        if (!tipc_nodes)
+        read_lock_bh(&tipc_net_lock);
+        if (!tipc_nodes) {
+                read_unlock_bh(&tipc_net_lock);
                 return tipc_cfg_reply_none();
+        }
 
         /* For now, get space for all other nodes
            (will need to modify this when slave nodes are supported */
 
         payload_size = TLV_SPACE(sizeof(node_info)) * (tipc_max_nodes - 1);
-        if (payload_size > 32768u)
+        if (payload_size > 32768u) {
+                read_unlock_bh(&tipc_net_lock);
                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
                                                    " (too many nodes)");
+        }
         buf = tipc_cfg_reply_alloc(payload_size);
-        if (!buf)
+        if (!buf) {
+                read_unlock_bh(&tipc_net_lock);
                 return NULL;
+        }
 
         /* Add TLVs for all nodes in scope */
 
@@ -624,6 +659,7 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
                                     &node_info, sizeof(node_info));
         }
 
+        read_unlock_bh(&tipc_net_lock);
         return buf;
 }
 
@@ -631,7 +667,7 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 {
         u32 domain;
         struct sk_buff *buf;
-        struct node *n_ptr;
+        struct tipc_node *n_ptr;
         struct tipc_link_info link_info;
         u32 payload_size;
 
@@ -646,16 +682,22 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
         if (tipc_mode != TIPC_NET_MODE)
                 return tipc_cfg_reply_none();
 
+        read_lock_bh(&tipc_net_lock);
+
         /* Get space for all unicast links + multicast link */
 
         payload_size = TLV_SPACE(sizeof(link_info)) *
                 (tipc_net.zones[tipc_zone(tipc_own_addr)]->links + 1);
-        if (payload_size > 32768u)
+        if (payload_size > 32768u) {
+                read_unlock_bh(&tipc_net_lock);
                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
                                                    " (too many links)");
+        }
         buf = tipc_cfg_reply_alloc(payload_size);
-        if (!buf)
+        if (!buf) {
+                read_unlock_bh(&tipc_net_lock);
                 return NULL;
+        }
 
         /* Add TLV for broadcast link */
 
@@ -671,6 +713,7 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 
                 if (!in_scope(domain, n_ptr->addr))
                         continue;
+                tipc_node_lock(n_ptr);
                 for (i = 0; i < MAX_BEARERS; i++) {
                         if (!n_ptr->links[i])
                                 continue;
@@ -680,7 +723,9 @@ 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));
                 }
+                tipc_node_unlock(n_ptr);
         }
 
+        read_unlock_bh(&tipc_net_lock);
         return buf;
 }