1 files changed, 38 insertions, 45 deletions

diff --git a/net/tipc/config.c b/net/tipc/config.c
index 48b5de2dbe60..41c8447276f9 100644
--- a/net/tipc/config.c
+++ b/net/tipc/config.c
@@ -291,13 +291,22 @@ static struct sk_buff *cfg_set_own_addr(void)
         if (!tipc_addr_node_valid(addr))
                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                                                    " (node address)");
-        if (tipc_own_addr)
+        if (tipc_mode == TIPC_NET_MODE)
                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
                                                    " (cannot change node address once assigned)");
+        tipc_own_addr = addr;
+
+        /* 
+         * Must release all spinlocks before calling start_net() because
+         * Linux version of TIPC calls eth_media_start() which calls
+         * register_netdevice_notifier() which may block!
+         *
+         * Temporarily releasing the lock should be harmless for non-Linux TIPC,
+         * but Linux version of eth_media_start() should really be reworked
+         * so that it can be called with spinlocks held.
+         */
 
         spin_unlock_bh(&config_lock);
-        tipc_core_stop_net();
-        tipc_own_addr = addr;
         tipc_core_start_net();
         spin_lock_bh(&config_lock);
         return tipc_cfg_reply_none();
@@ -350,50 +359,21 @@ static struct sk_buff *cfg_set_max_subscriptions(void)
 
 static struct sk_buff *cfg_set_max_ports(void)
 {
-        int orig_mode;
         u32 value;
 
         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
         value = *(u32 *)TLV_DATA(req_tlv_area);
         value = ntohl(value);
+        if (value == tipc_max_ports)
+                return tipc_cfg_reply_none();
         if (value != delimit(value, 127, 65535))
                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                                                    " (max ports must be 127-65535)");
-
-        if (value == tipc_max_ports)
-                return tipc_cfg_reply_none();
-
-        if (atomic_read(&tipc_user_count) > 2)
+        if (tipc_mode != TIPC_NOT_RUNNING)
                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
-                                                   " (cannot change max ports while TIPC users exist)");
-
-        spin_unlock_bh(&config_lock);
-        orig_mode = tipc_get_mode();
-        if (orig_mode == TIPC_NET_MODE)
-                tipc_core_stop_net();
-        tipc_core_stop();
+                        " (cannot change max ports while TIPC is active)");
         tipc_max_ports = value;
-        tipc_core_start();
-        if (orig_mode == TIPC_NET_MODE)
-                tipc_core_start_net();
-        spin_lock_bh(&config_lock);
-        return tipc_cfg_reply_none();
-}
-
-static struct sk_buff *set_net_max(int value, int *parameter)
-{
-        int orig_mode;
-
-        if (value != *parameter) {
-                orig_mode = tipc_get_mode();
-                if (orig_mode == TIPC_NET_MODE)
-                        tipc_core_stop_net();
-                *parameter = value;
-                if (orig_mode == TIPC_NET_MODE)
-                        tipc_core_start_net();
-        }
-
         return tipc_cfg_reply_none();
 }
 
@@ -405,10 +385,16 @@ static struct sk_buff *cfg_set_max_zones(void)
                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
         value = *(u32 *)TLV_DATA(req_tlv_area);
         value = ntohl(value);
+        if (value == tipc_max_zones)
+                return tipc_cfg_reply_none();
         if (value != delimit(value, 1, 255))
                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                                                    " (max zones must be 1-255)");
-        return set_net_max(value, &tipc_max_zones);
+        if (tipc_mode == TIPC_NET_MODE)
+                return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
+                        " (cannot change max zones once TIPC has joined a network)");
+        tipc_max_zones = value;
+        return tipc_cfg_reply_none();
 }
 
 static struct sk_buff *cfg_set_max_clusters(void)
@@ -419,8 +405,8 @@ static struct sk_buff *cfg_set_max_clusters(void)
                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
         value = *(u32 *)TLV_DATA(req_tlv_area);
         value = ntohl(value);
-        if (value != 1)
-                return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
+        if (value != delimit(value, 1, 1))
+                return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                                                    " (max clusters fixed at 1)");
         return tipc_cfg_reply_none();
 }
@@ -433,10 +419,16 @@ static struct sk_buff *cfg_set_max_nodes(void)
                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
         value = *(u32 *)TLV_DATA(req_tlv_area);
         value = ntohl(value);
+        if (value == tipc_max_nodes)
+                return tipc_cfg_reply_none();
         if (value != delimit(value, 8, 2047))
                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                                                    " (max nodes must be 8-2047)");
-        return set_net_max(value, &tipc_max_nodes);
+        if (tipc_mode == TIPC_NET_MODE)
+                return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
+                        " (cannot change max nodes once TIPC has joined a network)");
+        tipc_max_nodes = value;
+        return tipc_cfg_reply_none();
 }
 
 static struct sk_buff *cfg_set_max_slaves(void)
@@ -461,15 +453,16 @@ static struct sk_buff *cfg_set_netid(void)
                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
         value = *(u32 *)TLV_DATA(req_tlv_area);
         value = ntohl(value);
+        if (value == tipc_net_id)
+                return tipc_cfg_reply_none();
         if (value != delimit(value, 1, 9999))
                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                                                    " (network id must be 1-9999)");
-
-        if (tipc_own_addr)
+        if (tipc_mode == TIPC_NET_MODE)
                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
-                                                   " (cannot change network id once part of network)");
-        
-        return set_net_max(value, &tipc_net_id);
+                        " (cannot change network id once TIPC has joined a network)");
+        tipc_net_id = value;
+        return tipc_cfg_reply_none();
 }
 
 struct sk_buff *tipc_cfg_do_cmd(u32 orig_node, u16 cmd, const void *request_area,