[Qemu-devel] [PATCH v2 6/6] net: hub use lock to protect ports list

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfanl@linux.vnet.ibm.com>

Hub ports will run on multi-threads, so use lock to protect them.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 net/hub.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/net/hub.c b/net/hub.c
index 9c6c559..2970f8e 100644
--- a/net/hub.c
+++ b/net/hub.c
@@ -37,6 +37,7 @@ struct NetHub {
     int id;
     QLIST_ENTRY(NetHub) next;
     int num_ports;
+    QemuMutex ports_lock;
     QLIST_HEAD(, NetHubPort) ports;
 };
 
@@ -47,6 +48,7 @@ static ssize_t net_hub_receive(NetHub *hub, NetHubPort *source_port,
 {
     NetHubPort *port;
 
+    qemu_mutex_lock(&hub->ports_lock);
     QLIST_FOREACH(port, &hub->ports, next) {
         if (port == source_port) {
             continue;
@@ -54,6 +56,7 @@ static ssize_t net_hub_receive(NetHub *hub, NetHubPort *source_port,
 
         qemu_send_packet(&port->nc, buf, len);
     }
+    qemu_mutex_unlock(&hub->ports_lock);
     return len;
 }
 
@@ -63,6 +66,7 @@ static ssize_t net_hub_receive_iov(NetHub *hub, NetHubPort *source_port,
     NetHubPort *port;
     ssize_t len = iov_size(iov, iovcnt);
 
+    qemu_mutex_lock(&hub->ports_lock);
     QLIST_FOREACH(port, &hub->ports, next) {
         if (port == source_port) {
             continue;
@@ -70,6 +74,7 @@ static ssize_t net_hub_receive_iov(NetHub *hub, NetHubPort *source_port,
 
         qemu_sendv_packet(&port->nc, iov, iovcnt);
     }
+    qemu_mutex_unlock(&hub->ports_lock);
     return len;
 }
 
@@ -80,6 +85,7 @@ static NetHub *net_hub_new(int id)
     hub = g_malloc(sizeof(*hub));
     hub->id = id;
     hub->num_ports = 0;
+    qemu_mutex_init(&hub->ports_lock);
     QLIST_INIT(&hub->ports);
 
     QLIST_INSERT_HEAD(&hubs, hub, next);
@@ -93,16 +99,19 @@ static int net_hub_port_can_receive(NetClientState *nc)
     NetHubPort *src_port = DO_UPCAST(NetHubPort, nc, nc);
     NetHub *hub = src_port->hub;
 
+    qemu_mutex_lock(&hub->ports_lock);
     QLIST_FOREACH(port, &hub->ports, next) {
         if (port == src_port) {
             continue;
         }
 
         if (qemu_can_send_packet(&port->nc)) {
+            qemu_mutex_unlock(&hub->ports_lock);
             return 1;
         }
     }
 
+    qemu_mutex_unlock(&hub->ports_lock);
     return 0;
 }
 
@@ -155,8 +164,9 @@ static NetHubPort *net_hub_port_new(NetHub *hub, const char *name)
     port = DO_UPCAST(NetHubPort, nc, nc);
     port->id = id;
     port->hub = hub;
-
+    qemu_mutex_lock(&hub->ports_lock);
     QLIST_INSERT_HEAD(&hub->ports, port, next);
+    qemu_mutex_unlock(&hub->ports_lock);
 
     return port;
 }
@@ -197,14 +207,17 @@ NetClientState *net_hub_find_client_by_name(int hub_id, const char *name)
 
     QLIST_FOREACH(hub, &hubs, next) {
         if (hub->id == hub_id) {
+            qemu_mutex_lock(&hub->ports_lock);
             QLIST_FOREACH(port, &hub->ports, next) {
                 peer = port->nc.peer;
 
                 if (peer && strcmp(peer->name, name) == 0) {
                     netclient_ref(peer);
+                    qemu_mutex_unlock(&hub->ports_lock);
                     return peer;
                 }
             }
+            qemu_mutex_unlock(&hub->ports_lock);
         }
     }
     return NULL;
@@ -221,13 +234,16 @@ NetClientState *net_hub_port_find(int hub_id)
 
     QLIST_FOREACH(hub, &hubs, next) {
         if (hub->id == hub_id) {
+            qemu_mutex_lock(&hub->ports_lock);
             QLIST_FOREACH(port, &hub->ports, next) {
                 nc = port->nc.peer;
                 if (!nc) {
                     netclient_ref(&port->nc);
+                    qemu_mutex_unlock(&hub->ports_lock);
                     return &(port->nc);
                 }
             }
+            qemu_mutex_unlock(&hub->ports_lock);
             break;
         }
     }
@@ -247,12 +263,14 @@ void net_hub_info(Monitor *mon)
 
     QLIST_FOREACH(hub, &hubs, next) {
         monitor_printf(mon, "hub %d\n", hub->id);
+        qemu_mutex_lock(&hub->ports_lock);
         QLIST_FOREACH(port, &hub->ports, next) {
             if (port->nc.peer) {
                 monitor_printf(mon, " \\ ");
                 print_net_client(mon, port->nc.peer);
             }
         }
+        qemu_mutex_unlock(&hub->ports_lock);
     }
 }
 
@@ -309,6 +327,7 @@ void net_hub_check_clients(void)
     QLIST_FOREACH(hub, &hubs, next) {
         int has_nic = 0, has_host_dev = 0;
 
+        qemu_mutex_lock(&hub->ports_lock);
         QLIST_FOREACH(port, &hub->ports, next) {
             peer = port->nc.peer;
             if (!peer) {
@@ -331,6 +350,7 @@ void net_hub_check_clients(void)
                 break;
             }
         }
+        qemu_mutex_unlock(&hub->ports_lock);
         if (has_host_dev && !has_nic) {
             fprintf(stderr, "Warning: vlan %d with no nics\n", hub->id);
         }
@@ -346,12 +366,15 @@ bool net_hub_flush(NetClientState *nc)
 {
     NetHubPort *port;
     NetHubPort *source_port = DO_UPCAST(NetHubPort, nc, nc);
+    NetHub *hub = source_port->hub;
     int ret = 0;
 
+    qemu_mutex_lock(&hub->ports_lock);
     QLIST_FOREACH(port, &source_port->hub->ports, next) {
         if (port != source_port) {
             ret += qemu_net_queue_flush(port->nc.send_queue);
         }
     }
+    qemu_mutex_unlock(&hub->ports_lock);
     return ret ? true : false;
 }
-- 
1.8.1.4