-stable review patch. If anyone has any objections, please let us know. --------------------- From: Stephen Hemminger Kenji Kaneshige found this race between device removal and registration. On unregister it is possible for the old device to exist, because sysfs file is still open. A new device with 'eth%d' will select the same name, but sysfs kobject register will fial. The following changes the shutdown order slightly. It hold a removes the sysfs entries earlier (on unregister_netdevice), but holds a kobject reference. Then when todo runs the actual last put free happens. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller [chrisw: backport to 2.6.20] Signed-off-by: Chris Wright --- net/core/dev.c | 10 ++++++---- net/core/net-sysfs.c | 8 +++++++- 2 files changed, 13 insertions(+), 5 deletions(-) --- linux-2.6.20.13.orig/net/core/dev.c +++ linux-2.6.20.13/net/core/dev.c @@ -3138,7 +3138,6 @@ void netdev_run_todo(void) continue; } - netdev_unregister_sysfs(dev); dev->reg_state = NETREG_UNREGISTERED; netdev_wait_allrefs(dev); @@ -3149,11 +3148,11 @@ void netdev_run_todo(void) BUG_TRAP(!dev->ip6_ptr); BUG_TRAP(!dev->dn_ptr); - /* It must be the very last action, - * after this 'dev' may point to freed up memory. - */ if (dev->destructor) dev->destructor(dev); + + /* Free network device */ + kobject_put(&dev->dev.kobj); } out: @@ -3310,6 +3309,9 @@ int unregister_netdevice(struct net_devi /* Notifier chain MUST detach us from master device. */ BUG_TRAP(!dev->master); + /* Remove entries from sysfs */ + netdev_unregister_sysfs(dev); + /* Finish processing unregister after unlock */ net_set_todo(dev); --- linux-2.6.20.13.orig/net/core/net-sysfs.c +++ linux-2.6.20.13/net/core/net-sysfs.c @@ -440,9 +440,15 @@ static struct class net_class = { #endif }; +/* Delete sysfs entries but hold kobject reference until after all + * netdev references are gone. + */ void netdev_unregister_sysfs(struct net_device * net) { - class_device_del(&(net->class_dev)); + struct device *dev = &(net->dev); + + kobject_get(&dev->kobj); + device_del(dev); } /* Create sysfs entries for network device. */ -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/