diff options
author | Herbert Xu <herbert@gondor.apana.org.au> | 2007-07-30 17:03:38 -0700 |
---|---|---|
committer | David S. Miller <davem@sunset.davemloft.net> | 2007-07-31 02:28:15 -0700 |
commit | fcc5a03ac42564e9e255c1134dda47442289e466 (patch) | |
tree | 8be87d6dc1a58b8ccd27de930c17bc1c9c26bac9 /net/core | |
parent | aeed9e82cd258b9699eaa6568efefba9cc6d5f01 (diff) | |
download | op-kernel-dev-fcc5a03ac42564e9e255c1134dda47442289e466.zip op-kernel-dev-fcc5a03ac42564e9e255c1134dda47442289e466.tar.gz |
[NET]: Allow netdev REGISTER/CHANGENAME events to fail
This patch adds code to allow errors to be passed up from event
handlers of NETDEV_REGISTER and NETDEV_CHANGENAME. It also adds
the notifier_from_errno/notifier_to_errnor helpers to pass the
errno value up to the notifier caller.
If an error is detected when a device is registered, it causes
that operation to fail. A NETDEV_UNREGISTER will be sent to
all event handlers.
Similarly if NETDEV_CHANGENAME fails the original name is restored
and a new NETDEV_CHANGENAME event is sent.
As such all event handlers must be idempotent with respect to
these events.
When an event handler is registered NETDEV_REGISTER events are
sent for all devices currently registered. Should any of them
fail, we will send NETDEV_GOING_DOWN/NETDEV_DOWN/NETDEV_UNREGISTER
events to that handler for the devices which have already been
registered with it. The handler registration itself will fail.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r-- | net/core/dev.c | 62 |
1 files changed, 52 insertions, 10 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 346cbf6..6cc8a70 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -817,7 +817,9 @@ int dev_alloc_name(struct net_device *dev, const char *name) */ int dev_change_name(struct net_device *dev, char *newname) { + char oldname[IFNAMSIZ]; int err = 0; + int ret; ASSERT_RTNL(); @@ -827,6 +829,8 @@ int dev_change_name(struct net_device *dev, char *newname) if (!dev_valid_name(newname)) return -EINVAL; + memcpy(oldname, dev->name, IFNAMSIZ); + if (strchr(newname, '%')) { err = dev_alloc_name(dev, newname); if (err < 0) @@ -838,6 +842,7 @@ int dev_change_name(struct net_device *dev, char *newname) else strlcpy(dev->name, newname, IFNAMSIZ); +rollback: device_rename(&dev->dev, dev->name); write_lock_bh(&dev_base_lock); @@ -845,7 +850,20 @@ int dev_change_name(struct net_device *dev, char *newname) hlist_add_head(&dev->name_hlist, dev_name_hash(dev->name)); write_unlock_bh(&dev_base_lock); - raw_notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev); + ret = raw_notifier_call_chain(&netdev_chain, NETDEV_CHANGENAME, dev); + ret = notifier_to_errno(ret); + + if (ret) { + if (err) { + printk(KERN_ERR + "%s: name change rollback failed: %d.\n", + dev->name, ret); + } else { + err = ret; + memcpy(dev->name, oldname, IFNAMSIZ); + goto rollback; + } + } return err; } @@ -1058,20 +1076,43 @@ int dev_close(struct net_device *dev) int register_netdevice_notifier(struct notifier_block *nb) { struct net_device *dev; + struct net_device *last; int err; rtnl_lock(); err = raw_notifier_chain_register(&netdev_chain, nb); - if (!err) { - for_each_netdev(dev) { - nb->notifier_call(nb, NETDEV_REGISTER, dev); + if (err) + goto unlock; - if (dev->flags & IFF_UP) - nb->notifier_call(nb, NETDEV_UP, dev); - } + for_each_netdev(dev) { + err = nb->notifier_call(nb, NETDEV_REGISTER, dev); + err = notifier_to_errno(err); + if (err) + goto rollback; + + if (!(dev->flags & IFF_UP)) + continue; + + nb->notifier_call(nb, NETDEV_UP, dev); } + +unlock: rtnl_unlock(); return err; + +rollback: + last = dev; + for_each_netdev(dev) { + if (dev == last) + break; + + if (dev->flags & IFF_UP) { + nb->notifier_call(nb, NETDEV_GOING_DOWN, dev); + nb->notifier_call(nb, NETDEV_DOWN, dev); + } + nb->notifier_call(nb, NETDEV_UNREGISTER, dev); + } + goto unlock; } /** @@ -3434,9 +3475,10 @@ int register_netdevice(struct net_device *dev) write_unlock_bh(&dev_base_lock); /* Notify protocols, that a new device appeared. */ - raw_notifier_call_chain(&netdev_chain, NETDEV_REGISTER, dev); - - ret = 0; + ret = raw_notifier_call_chain(&netdev_chain, NETDEV_REGISTER, dev); + ret = notifier_to_errno(ret); + if (ret) + unregister_netdevice(dev); out: return ret; |