From 46415c9085ef6b7386943b1714754150487b6cff Mon Sep 17 00:00:00 2001
From: Jesse Gross <jesse@nicira.com>
Date: Mon, 18 Jan 2010 15:05:58 -0500
Subject: [PATCH] netdev-linux: Use the netdev list of devices instead of
 cachemap.

We previously maintained a list of open devices inside of the
linux netdev.  Since the netdev library now maintains this list,
it is better to use that list instead of our own.
---
 lib/netdev-linux.c    | 24 +++++++++++++++---------
 lib/netdev-provider.h |  3 +++
 lib/netdev.c          | 27 +++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index f2a6a5d04..ccc3f845c 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -75,7 +75,7 @@
 #endif
 
 static struct rtnetlink_notifier netdev_linux_cache_notifier;
-static struct shash cache_map = SHASH_INITIALIZER(&cache_map);
+static int cache_notifier_refcount;
 
 enum {
     VALID_IFINDEX = 1 << 0,
@@ -220,16 +220,22 @@ netdev_linux_cache_cb(const struct rtnetlink_change *change,
 {
     struct netdev_dev_linux *dev;
     if (change) {
-        dev = shash_find_data(&cache_map, change->ifname);
-        if (dev) {
+        struct netdev_dev *base_dev = netdev_dev_from_name(change->ifname);
+        if (base_dev) {
+            dev = netdev_dev_linux_cast(base_dev);
             dev->cache_valid = 0;
         }
     } else {
+        struct shash device_shash;
         struct shash_node *node;
-        SHASH_FOR_EACH (node, &cache_map) {
+
+        shash_init(&device_shash);
+        netdev_dev_get_devices(&netdev_linux_class, &device_shash);
+        SHASH_FOR_EACH (node, &device_shash) {
             dev = node->data;
             dev->cache_valid = 0;
         }
+        shash_destroy(&device_shash);
     }
 }
 
@@ -573,18 +579,18 @@ netdev_linux_create_system(const char *name, const char *type UNUSED,
         VLOG_WARN("%s: arguments for system devices should be empty", name);
     }
 
-    if (shash_is_empty(&cache_map)) {
+    if (!cache_notifier_refcount) {
         error = rtnetlink_notifier_register(&netdev_linux_cache_notifier,
                                             netdev_linux_cache_cb, NULL);
         if (error) {
             return error;
         }
     }
+    cache_notifier_refcount++;
 
     netdev_dev = xzalloc(sizeof *netdev_dev);
-    netdev_dev->shash_node = shash_add(&cache_map, name, netdev_dev);
-
     netdev_dev_init(&netdev_dev->netdev_dev, name, &netdev_linux_class);
+
     *netdev_devp = &netdev_dev->netdev_dev;
     return 0;
 }
@@ -787,9 +793,9 @@ netdev_linux_destroy(struct netdev_dev *netdev_dev_)
     const char *type = netdev_dev_get_type(netdev_dev_);
 
     if (!strcmp(type, "system")) {
-        shash_delete(&cache_map, netdev_dev->shash_node);
+        cache_notifier_refcount--;
 
-        if (shash_is_empty(&cache_map)) {
+        if (!cache_notifier_refcount) {
             rtnetlink_notifier_unregister(&netdev_linux_cache_notifier);
         }
     } else if (!strcmp(type, "tap")) {
diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
index 4148c6cfd..b009c8dc7 100644
--- a/lib/netdev-provider.h
+++ b/lib/netdev-provider.h
@@ -42,6 +42,9 @@ void netdev_dev_init(struct netdev_dev *, const char *name,
 void netdev_dev_uninit(struct netdev_dev *, bool destroy);
 const char *netdev_dev_get_type(const struct netdev_dev *);
 const char *netdev_dev_get_name(const struct netdev_dev *);
+struct netdev_dev *netdev_dev_from_name(const char *name);
+void netdev_dev_get_devices(const struct netdev_class *,
+                            struct shash *device_list);
 
 static inline void netdev_dev_assert_class(const struct netdev_dev *netdev_dev,
                                            const struct netdev_class *class)
diff --git a/lib/netdev.c b/lib/netdev.c
index 8d243e9e7..6a95e1a4f 100644
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -889,6 +889,33 @@ netdev_dev_get_name(const struct netdev_dev *netdev_dev)
     return netdev_dev->name;
 }
 
+/* Returns the netdev_dev with 'name' or NULL if there is none.
+ *
+ * The caller must not free the returned value. */
+struct netdev_dev *
+netdev_dev_from_name(const char *name)
+{
+    return shash_find_data(&netdev_dev_shash, name);
+}
+
+/* Fills 'device_list' with devices that match 'class'.
+ *
+ * The caller is responsible for initializing and destroying 'device_list'
+ * but the contained netdev_devs must not be freed. */
+void
+netdev_dev_get_devices(const struct netdev_class *class,
+                       struct shash *device_list)
+{
+    struct shash_node *node;
+    SHASH_FOR_EACH (node, &netdev_dev_shash) {
+        struct netdev_dev *dev = node->data;
+
+        if (dev->class == class) {
+            shash_add(device_list, node->name, node->data);
+        }
+    }
+}
+
 /* Initializes 'netdev' as a instance of the netdev_dev.
  *
  * This function adds 'netdev' to a netdev-owned linked list, so it is very
-- 
2.43.0