[PATCH] uml: network driver locking and code cleanup

Add some missing locking to walks of the transports and opened lists.

Delete some dead code.

Comment the lack of some locking.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index c1838645ae28b54ce7f7f3e020ce62eaeba27cdf..04e31f86c10afb88f21002b7b0eb8c261e3490a9 100644 (file)
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -502,7 +502,7 @@ static DEFINE_SPINLOCK(transports_lock);
 static LIST_HEAD(transports);
 
 /* Filled in during early boot */
-struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
+static LIST_HEAD(eth_cmd_line);
 
 static int check_transport(struct transport *transport, char *eth, int n,
                           void **init_out, char **mac_out)
@@ -563,7 +563,9 @@ static int eth_setup_common(char *str, int index)
        struct transport *transport;
        void *init;
        char *mac = NULL;
+       int found = 0;
 
+       spin_lock(&transports_lock);
        list_for_each(ele, &transports){
                transport = list_entry(ele, struct transport, list);
                if(!check_transport(transport, str, index, &init, &mac))
@@ -572,9 +574,12 @@ static int eth_setup_common(char *str, int index)
                        eth_configure(index, init, mac, transport);
                        kfree(init);
                }
-               return 1;
+               found = 1;
+               break;
        }
-       return 0;
+
+       spin_unlock(&transports_lock);
+       return found;
 }
 
 static int eth_setup(char *str)
@@ -610,24 +615,6 @@ __uml_help(eth_setup,
 "    Configure a network device.\n\n"
 );
 
-#if 0
-static int eth_init(void)
-{
-       struct list_head *ele, *next;
-       struct eth_init *eth;
-
-       list_for_each_safe(ele, next, &eth_cmd_line){
-               eth = list_entry(ele, struct eth_init, list);
-
-               if(eth_setup_common(eth->init, eth->index))
-                       list_del(&eth->list);
-       }
-
-       return(1);
-}
-__initcall(eth_init);
-#endif
-
 static int net_config(char *str, char **error_out)
 {
        int n, err;
@@ -729,6 +716,7 @@ static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
        return NOTIFY_DONE;
 }
 
+/* uml_net_init shouldn't be called twice on two CPUs at the same time */
 struct notifier_block uml_inetaddr_notifier = {
        .notifier_call          = uml_inetaddr_event,
 };
@@ -747,18 +735,21 @@ static int uml_net_init(void)
         * didn't get a chance to run for them.  This fakes it so that
         * addresses which have already been set up get handled properly.
         */
+       spin_lock(&opened_lock);
        list_for_each(ele, &opened){
                lp = list_entry(ele, struct uml_net_private, list);
                ip = lp->dev->ip_ptr;
-               if(ip == NULL) continue;
+               if(ip == NULL)
+                       continue;
                in = ip->ifa_list;
                while(in != NULL){
                        uml_inetaddr_event(NULL, NETDEV_UP, in);
                        in = in->ifa_next;
                }
        }
+       spin_unlock(&opened_lock);
 
-       return(0);
+       return 0;
 }
 
 __initcall(uml_net_init);
@@ -768,13 +759,16 @@ static void close_devices(void)
        struct list_head *ele;
        struct uml_net_private *lp;
 
+       spin_lock(&opened_lock);
        list_for_each(ele, &opened){
                lp = list_entry(ele, struct uml_net_private, list);
                free_irq(lp->dev->irq, lp->dev);
                if((lp->close != NULL) && (lp->fd >= 0))
                        (*lp->close)(lp->fd, &lp->user);
-               if(lp->remove != NULL) (*lp->remove)(&lp->user);
+               if(lp->remove != NULL)
+                       (*lp->remove)(&lp->user);
        }
+       spin_unlock(&opened_lock);
 }
 
 __uml_exitcall(close_devices);