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-rw-r--r--net/tipc/net.c71
1 files changed, 34 insertions, 37 deletions
diff --git a/net/tipc/net.c b/net/tipc/net.c
index 4c564eb69e1a..f64375e7f99f 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -39,45 +39,41 @@
#include "name_distr.h"
#include "subscr.h"
#include "port.h"
+#include "socket.h"
#include "node.h"
#include "config.h"
/*
* The TIPC locking policy is designed to ensure a very fine locking
* granularity, permitting complete parallel access to individual
- * port and node/link instances. The code consists of three major
+ * port and node/link instances. The code consists of four major
* locking domains, each protected with their own disjunct set of locks.
*
- * 1: The routing hierarchy.
- * Comprises the structures 'zone', 'cluster', 'node', 'link'
- * and 'bearer'. The whole hierarchy is protected by a big
- * read/write lock, tipc_net_lock, to enssure that nothing is added
- * or removed while code is accessing any of these structures.
- * This layer must not be called from the two others while they
- * hold any of their own locks.
- * Neither must it itself do any upcalls to the other two before
- * it has released tipc_net_lock and other protective locks.
+ * 1: The bearer level.
+ * RTNL lock is used to serialize the process of configuring bearer
+ * on update side, and RCU lock is applied on read side to make
+ * bearer instance valid on both paths of message transmission and
+ * reception.
*
- * Within the tipc_net_lock domain there are two sub-domains;'node' and
- * 'bearer', where local write operations are permitted,
- * provided that those are protected by individual spin_locks
- * per instance. Code holding tipc_net_lock(read) and a node spin_lock
- * is permitted to poke around in both the node itself and its
- * subordinate links. I.e, it can update link counters and queues,
- * change link state, send protocol messages, and alter the
- * "active_links" array in the node; but it can _not_ remove a link
- * or a node from the overall structure.
- * Correspondingly, individual bearers may change status within a
- * tipc_net_lock(read), protected by an individual spin_lock ber bearer
- * instance, but it needs tipc_net_lock(write) to remove/add any bearers.
+ * 2: The node and link level.
+ * All node instances are saved into two tipc_node_list and node_htable
+ * lists. The two lists are protected by node_list_lock on write side,
+ * and they are guarded with RCU lock on read side. Especially node
+ * instance is destroyed only when TIPC module is removed, and we can
+ * confirm that there has no any user who is accessing the node at the
+ * moment. Therefore, Except for iterating the two lists within RCU
+ * protection, it's no needed to hold RCU that we access node instance
+ * in other places.
*
+ * In addition, all members in node structure including link instances
+ * are protected by node spin lock.
*
- * 2: The transport level of the protocol.
- * This consists of the structures port, (and its user level
- * representations, such as user_port and tipc_sock), reference and
- * tipc_user (port.c, reg.c, socket.c).
+ * 3: The transport level of the protocol.
+ * This consists of the structures port, (and its user level
+ * representations, such as user_port and tipc_sock), reference and
+ * tipc_user (port.c, reg.c, socket.c).
*
- * This layer has four different locks:
+ * This layer has four different locks:
* - The tipc_port spin_lock. This is protecting each port instance
* from parallel data access and removal. Since we can not place
* this lock in the port itself, it has been placed in the
@@ -96,7 +92,7 @@
* There are two such lists; 'port_list', which is used for management,
* and 'wait_list', which is used to queue ports during congestion.
*
- * 3: The name table (name_table.c, name_distr.c, subscription.c)
+ * 4: The name table (name_table.c, name_distr.c, subscription.c)
* - There is one big read/write-lock (tipc_nametbl_lock) protecting the
* overall name table structure. Nothing must be added/removed to
* this structure without holding write access to it.
@@ -108,8 +104,6 @@
* - A local spin_lock protecting the queue of subscriber events.
*/
-DEFINE_RWLOCK(tipc_net_lock);
-
static void net_route_named_msg(struct sk_buff *buf)
{
struct tipc_msg *msg = buf_msg(buf);
@@ -148,7 +142,7 @@ void tipc_net_route_msg(struct sk_buff *buf)
if (msg_mcast(msg))
tipc_port_mcast_rcv(buf, NULL);
else if (msg_destport(msg))
- tipc_port_rcv(buf);
+ tipc_sk_rcv(buf);
else
net_route_named_msg(buf);
return;
@@ -171,22 +165,25 @@ void tipc_net_route_msg(struct sk_buff *buf)
tipc_link_xmit(buf, dnode, msg_link_selector(msg));
}
-void tipc_net_start(u32 addr)
+int tipc_net_start(u32 addr)
{
char addr_string[16];
+ int res;
- write_lock_bh(&tipc_net_lock);
tipc_own_addr = addr;
tipc_named_reinit();
tipc_port_reinit();
- tipc_bclink_init();
- write_unlock_bh(&tipc_net_lock);
+ res = tipc_bclink_init();
+ if (res)
+ return res;
tipc_nametbl_publish(TIPC_CFG_SRV, tipc_own_addr, tipc_own_addr,
TIPC_ZONE_SCOPE, 0, tipc_own_addr);
+
pr_info("Started in network mode\n");
pr_info("Own node address %s, network identity %u\n",
tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id);
+ return 0;
}
void tipc_net_stop(void)
@@ -195,11 +192,11 @@ void tipc_net_stop(void)
return;
tipc_nametbl_withdraw(TIPC_CFG_SRV, tipc_own_addr, 0, tipc_own_addr);
- write_lock_bh(&tipc_net_lock);
+ rtnl_lock();
tipc_bearer_stop();
tipc_bclink_stop();
tipc_node_stop();
- write_unlock_bh(&tipc_net_lock);
+ rtnl_unlock();
pr_info("Left network mode\n");
}