On Tue, 08 Apr 2003 15:25:27 -0700 (PDT) "David S. Miller" <davem@redhat.com> wrote: > From: Stephen Hemminger <shemminger@osdl.org> > Date: Tue, 8 Apr 2003 11:28:05 -0700 > > /* NOTE: We have a reference to the real device, > * so hold on to the reference. > */ > - MOD_INC_USE_COUNT; /* Add was a success!! */ > + try_module_get(THIS_MODULE); > + > > You have to check the return value and error accordingly. > The administrator can do a waiting module unload which causes > all try_module_get()'s to fail so that no new references can > be added to the module. > > Please, if you're going to convert things, do it correctly. That's what I get for copying bugs from other code ... Here is a repost which handles the race of unload and uncompleted init. diff -urN -X dontdiff linux-2.5/net/8021q/vlan.c linux-2.5-vlan/net/8021q/vlan.c --- linux-2.5/net/8021q/vlan.c 2003-04-03 12:13:09.000000000 -0800 +++ linux-2.5-vlan/net/8021q/vlan.c 2003-04-08 15:49:45.000000000 -0700 @@ -29,7 +29,6 @@ #include <net/p8022.h> #include <net/arp.h> #include <linux/rtnetlink.h> -#include <linux/brlock.h> #include <linux/notifier.h> #include <linux/if_vlan.h> @@ -68,7 +67,6 @@ .dev =NULL, .func = vlan_skb_recv, /* VLAN receive method */ .data = (void *)(-1), /* Set here '(void *)1' when this code can SHARE SKBs */ - .next = NULL }; /* End of global variables definitions. */ @@ -231,9 +229,8 @@ real_dev->vlan_rx_kill_vid(real_dev, vlan_id); } - br_write_lock(BR_NETPROTO_LOCK); grp->vlan_devices[vlan_id] = NULL; - br_write_unlock(BR_NETPROTO_LOCK); + synchronize_net(); /* Caller unregisters (and if necessary, puts) @@ -266,7 +263,7 @@ ret = 1; } - MOD_DEC_USE_COUNT; + module_put(THIS_MODULE); } } @@ -433,6 +430,7 @@ /* set up method calls */ new_dev->init = vlan_dev_init; new_dev->destructor = vlan_dev_destruct; + new_dev->owner = THIS_MODULE; /* new_dev->ifindex = 0; it will be set when added to * the global list. @@ -540,16 +538,22 @@ register_netdevice(new_dev); rtnl_unlock(); - + /* NOTE: We have a reference to the real device, * so hold on to the reference. */ - MOD_INC_USE_COUNT; /* Add was a success!! */ + if (!try_module_get(THIS_MODULE)) + goto out_module_dying; + #ifdef VLAN_DEBUG printk(VLAN_DBG "Allocated new device successfully, returning.\n"); #endif return new_dev; +out_module_dying: + rtnl_lock(); + unregister_netdevice(new_dev); + out_free_newdev_priv: kfree(new_dev->priv); diff -urN -X dontdiff linux-2.5/net/8021q/vlan_dev.c linux-2.5-vlan/net/8021q/vlan_dev.c --- linux-2.5/net/8021q/vlan_dev.c 2003-04-03 12:13:09.000000000 -0800 +++ linux-2.5-vlan/net/8021q/vlan_dev.c 2003-04-08 15:50:58.000000000 -0700 @@ -31,7 +31,6 @@ #include <net/datalink.h> #include <net/p8022.h> #include <net/arp.h> -#include <linux/brlock.h> #include "vlan.h" #include "vlanproc.h" - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
