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uml: network interface hotplug error handling

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This fixes a number of problems associated with network interface hotplug.

The userspace initialization function can fail in some cases, but the
failure was never passed back to eth_configure, which proceeded with the
configuration.  This results in a zombie device that is present, but can't
work.  This is fixed by allowing the initialization routines to return an
error, which is checked, and the configuration aborted on failure.

eth_configure failed to check for many failures.  Even when it did check,
it didn't undo whatever initializations has already happened, so a present,
but partially initialized and non-working device could result.  It now
checks everything that can fail, and bails out, undoing whatever had been
done.

The return value of eth_configure was always ignored, so it is now just
void.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jeff Dike
2007-05-06 14:51:04 -07:00
committed by Linus Torvalds
parent b16895b63c
commit f34d9d2dcb
9 changed files with 64 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

81
arch/um/drivers/net_kern.c
View File

@@ -325,8 +325,8 @@ static struct platform_driver uml_net_driver = {
};
static int driver_registered;
static int eth_configure(int n, void *init, char *mac,
struct transport *transport)
static void eth_configure(int n, void *init, char *mac,
struct transport *transport)
{
struct uml_net *device;
struct net_device *dev;
@@ -339,16 +339,12 @@ static int eth_configure(int n, void *init, char *mac,
device = kzalloc(sizeof(*device), GFP_KERNEL);
if (device == NULL) {
printk(KERN_ERR "eth_configure failed to allocate uml_net\n");
return(1);
return;
}
INIT_LIST_HEAD(&device->list);
device->index = n;
spin_lock(&devices_lock);
list_add(&device->list, &devices);
spin_unlock(&devices_lock);
setup_etheraddr(mac, device->mac);
printk(KERN_INFO "Netdevice %d ", n);
@@ -360,7 +356,7 @@ static int eth_configure(int n, void *init, char *mac,
dev = alloc_etherdev(size);
if (dev == NULL) {
printk(KERN_ERR "eth_configure: failed to allocate device\n");
return 1;
goto out_free_device;
}
lp = dev->priv;
@@ -376,7 +372,8 @@ static int eth_configure(int n, void *init, char *mac,
}
device->pdev.id = n;
device->pdev.name = DRIVER_NAME;
platform_device_register(&device->pdev);
if(platform_device_register(&device->pdev))
goto out_free_netdev;
SET_NETDEV_DEV(dev,&device->pdev.dev);
/* If this name ends up conflicting with an existing registered
@@ -386,31 +383,12 @@ static int eth_configure(int n, void *init, char *mac,
snprintf(dev->name, sizeof(dev->name), "eth%d", n);
device->dev = dev;
/*
* These just fill in a data structure, so there's no failure
* to be worried about.
*/
(*transport->kern->init)(dev, init);
dev->mtu = transport->user->max_packet;
dev->open = uml_net_open;
dev->hard_start_xmit = uml_net_start_xmit;
dev->stop = uml_net_close;
dev->get_stats = uml_net_get_stats;
dev->set_multicast_list = uml_net_set_multicast_list;
dev->tx_timeout = uml_net_tx_timeout;
dev->set_mac_address = uml_net_set_mac;
dev->change_mtu = uml_net_change_mtu;
dev->ethtool_ops = &uml_net_ethtool_ops;
dev->watchdog_timeo = (HZ >> 1);
dev->irq = UM_ETH_IRQ;
rtnl_lock();
err = register_netdevice(dev);
rtnl_unlock();
if (err) {
device->dev = NULL;
/* XXX: should we call ->remove() here? */
free_netdev(dev);
return 1;
}
/* lp.user is the first four bytes of the transport data, which
* has already been initialized. This structure assignment will
* overwrite that, so we make sure that .user gets overwritten with
@@ -438,12 +416,45 @@ static int eth_configure(int n, void *init, char *mac,
lp->tl.function = uml_net_user_timer_expire;
memcpy(lp->mac, device->mac, sizeof(lp->mac));
if (transport->user->init)
(*transport->user->init)(&lp->user, dev);
if ((transport->user->init != NULL) &&
((*transport->user->init)(&lp->user, dev) != 0))
goto out_unregister;
set_ether_mac(dev, device->mac);
dev->mtu = transport->user->max_packet;
dev->open = uml_net_open;
dev->hard_start_xmit = uml_net_start_xmit;
dev->stop = uml_net_close;
dev->get_stats = uml_net_get_stats;
dev->set_multicast_list = uml_net_set_multicast_list;
dev->tx_timeout = uml_net_tx_timeout;
dev->set_mac_address = uml_net_set_mac;
dev->change_mtu = uml_net_change_mtu;
dev->ethtool_ops = &uml_net_ethtool_ops;
dev->watchdog_timeo = (HZ >> 1);
dev->irq = UM_ETH_IRQ;
return 0;
rtnl_lock();
err = register_netdevice(dev);
rtnl_unlock();
if (err)
goto out_undo_user_init;
spin_lock(&devices_lock);
list_add(&device->list, &devices);
spin_unlock(&devices_lock);
return;
out_undo_user_init:
if (transport->user->init != NULL)
(*transport->user->remove)(&lp->user);
out_unregister:
platform_device_unregister(&device->pdev);
out_free_netdev:
free_netdev(dev);
out_free_device: ;
kfree(device);
}
static struct uml_net *find_device(int n)