2007-01-05 18:47:41

by Jeff Dike

Subject: [PATCH 1/9] 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 <[email protected]>
--
arch/um/drivers/net_kern.c | 42 ++++++++++++++++++------------------------
1 file changed, 18 insertions(+), 24 deletions(-)

Index: linux-2.6.18-mm/arch/um/drivers/net_kern.c
===================================================================
--- linux-2.6.18-mm.orig/arch/um/drivers/net_kern.c 2007-01-01 12:18:47.000000000 -0500
+++ linux-2.6.18-mm/arch/um/drivers/net_kern.c 2007-01-01 12:35:12.000000000 -0500
@@ -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, i
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, i
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 not
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);