Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh...

[pandora-kernel.git] / net / 9p / mod.c

diff --git a/net/9p/mod.c b/net/9p/mod.c
index bdee1fb..1084feb 100644 (file)
--- a/net/9p/mod.c
+++ b/net/9p/mod.c
@@ -31,6 +31,7 @@
 #include <linux/parser.h>
 #include <net/9p/transport.h>
 #include <linux/list.h>
+#include <linux/spinlock.h>
 
 #ifdef CONFIG_NET_9P_DEBUG
 unsigned int p9_debug_level = 0;       /* feature-rific global debug level  */
@@ -44,8 +45,8 @@ MODULE_PARM_DESC(debug, "9P debugging level");
  *
  */
 
+static DEFINE_SPINLOCK(v9fs_trans_lock);
 static LIST_HEAD(v9fs_trans_list);
-static struct p9_trans_module *v9fs_default_transport;
 
 /**
  * v9fs_register_trans - register a new transport with 9p
@@ -54,48 +55,87 @@ static struct p9_trans_module *v9fs_default_transport;
  */
 void v9fs_register_trans(struct p9_trans_module *m)
 {
+       spin_lock(&v9fs_trans_lock);
        list_add_tail(&m->list, &v9fs_trans_list);
-       if (m->def)
-               v9fs_default_transport = m;
+       spin_unlock(&v9fs_trans_lock);
 }
 EXPORT_SYMBOL(v9fs_register_trans);
 
 /**
- * v9fs_match_trans - match transport versus registered transports
+ * v9fs_unregister_trans - unregister a 9p transport
+ * @m: the transport to remove
+ *
+ */
+void v9fs_unregister_trans(struct p9_trans_module *m)
+{
+       spin_lock(&v9fs_trans_lock);
+       list_del_init(&m->list);
+       spin_unlock(&v9fs_trans_lock);
+}
+EXPORT_SYMBOL(v9fs_unregister_trans);
+
+/**
+ * v9fs_get_trans_by_name - get transport with the matching name
  * @name: string identifying transport
  *
  */
-struct p9_trans_module *v9fs_match_trans(const substring_t *name)
+struct p9_trans_module *v9fs_get_trans_by_name(const substring_t *name)
 {
-       struct list_head *p;
-       struct p9_trans_module *t = NULL;
-
-       list_for_each(p, &v9fs_trans_list) {
-               t = list_entry(p, struct p9_trans_module, list);
-               if (strncmp(t->name, name->from, name->to-name->from) == 0)
-                       return t;
-       }
-       return NULL;
+       struct p9_trans_module *t, *found = NULL;
+
+       spin_lock(&v9fs_trans_lock);
+
+       list_for_each_entry(t, &v9fs_trans_list, list)
+               if (strncmp(t->name, name->from, name->to-name->from) == 0 &&
+                   try_module_get(t->owner)) {
+                       found = t;
+                       break;
+               }
+
+       spin_unlock(&v9fs_trans_lock);
+       return found;
 }
-EXPORT_SYMBOL(v9fs_match_trans);
+EXPORT_SYMBOL(v9fs_get_trans_by_name);
 
 /**
- * v9fs_default_trans - returns pointer to default transport
+ * v9fs_get_default_trans - get the default transport
  *
  */
 
-struct p9_trans_module *v9fs_default_trans(void)
+struct p9_trans_module *v9fs_get_default_trans(void)
 {
-       if (v9fs_default_transport)
-               return v9fs_default_transport;
-       else if (!list_empty(&v9fs_trans_list))
-               return list_first_entry(&v9fs_trans_list,
-                                       struct p9_trans_module, list);
-       else
-               return NULL;
+       struct p9_trans_module *t, *found = NULL;
+
+       spin_lock(&v9fs_trans_lock);
+
+       list_for_each_entry(t, &v9fs_trans_list, list)
+               if (t->def && try_module_get(t->owner)) {
+                       found = t;
+                       break;
+               }
+
+       if (!found)
+               list_for_each_entry(t, &v9fs_trans_list, list)
+                       if (try_module_get(t->owner)) {
+                               found = t;
+                               break;
+                       }
+
+       spin_unlock(&v9fs_trans_lock);
+       return found;
 }
-EXPORT_SYMBOL(v9fs_default_trans);
+EXPORT_SYMBOL(v9fs_get_default_trans);
 
+/**
+ * v9fs_put_trans - put trans
+ * @m: transport to put
+ *
+ */
+void v9fs_put_trans(struct p9_trans_module *m)
+{
+       if (m)
+               module_put(m->owner);
+}
 
 /**
  * v9fs_init - Initialize module
@@ -120,6 +160,8 @@ static int __init init_p9(void)
 static void __exit exit_p9(void)
 {
        printk(KERN_INFO "Unloading 9P2000 support\n");
+
+       p9_trans_fd_exit();
 }
 
 module_init(init_p9)