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authorPatrick McHardy <kaber@trash.net>2010-02-26 06:34:53 +0000
committerDavid S. Miller <davem@davemloft.net>2010-02-27 02:43:40 -0800
commitbd38081160bb3d036db98472e537b6a7dd4da51a (patch)
tree26af1cae5e2dda3269da6f812586e93954582d54 /net/core
parenta2835763e130c343ace5320c20d33c281e7097b7 (diff)
downloadop-kernel-dev-bd38081160bb3d036db98472e537b6a7dd4da51a.zip
op-kernel-dev-bd38081160bb3d036db98472e537b6a7dd4da51a.tar.gz
dev: support deferring device flag change notifications
Split dev_change_flags() into two functions: __dev_change_flags() to perform the actual changes and __dev_notify_flags() to invoke netdevice notifiers. This will be used by rtnl_link to defer netlink notifications until the device has been fully configured. This changes ordering of some operations, in particular: - netlink notifications are sent after all changes have been performed. As a side effect this surpresses one unnecessary netlink message when the IFF_UP and other flags are changed simultaneously. - The NETDEV_UP/NETDEV_DOWN and NETDEV_CHANGE notifiers are invoked after all changes have been performed. Their relative is unchanged. - net_dmaengine_put() is invoked before the NETDEV_DOWN notifier instead of afterwards. This should not make any difference since both RX and TX are already shut down at this point. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c163
-rw-r--r--net/core/rtnetlink.c2
2 files changed, 104 insertions, 61 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 75332b0..e5972f7 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1113,19 +1113,7 @@ void dev_load(struct net *net, const char *name)
}
EXPORT_SYMBOL(dev_load);
-/**
- * dev_open - prepare an interface for use.
- * @dev: device to open
- *
- * Takes a device from down to up state. The device's private open
- * function is invoked and then the multicast lists are loaded. Finally
- * the device is moved into the up state and a %NETDEV_UP message is
- * sent to the netdev notifier chain.
- *
- * Calling this function on an active interface is a nop. On a failure
- * a negative errno code is returned.
- */
-int dev_open(struct net_device *dev)
+static int __dev_open(struct net_device *dev)
{
const struct net_device_ops *ops = dev->netdev_ops;
int ret;
@@ -1133,13 +1121,6 @@ int dev_open(struct net_device *dev)
ASSERT_RTNL();
/*
- * Is it already up?
- */
-
- if (dev->flags & IFF_UP)
- return 0;
-
- /*
* Is it even present?
*/
if (!netif_device_present(dev))
@@ -1187,36 +1168,57 @@ int dev_open(struct net_device *dev)
* Wakeup transmit queue engine
*/
dev_activate(dev);
-
- /*
- * ... and announce new interface.
- */
- call_netdevice_notifiers(NETDEV_UP, dev);
}
return ret;
}
-EXPORT_SYMBOL(dev_open);
/**
- * dev_close - shutdown an interface.
- * @dev: device to shutdown
+ * dev_open - prepare an interface for use.
+ * @dev: device to open
*
- * This function moves an active device into down state. A
- * %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
- * is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
- * chain.
+ * Takes a device from down to up state. The device's private open
+ * function is invoked and then the multicast lists are loaded. Finally
+ * the device is moved into the up state and a %NETDEV_UP message is
+ * sent to the netdev notifier chain.
+ *
+ * Calling this function on an active interface is a nop. On a failure
+ * a negative errno code is returned.
*/
-int dev_close(struct net_device *dev)
+int dev_open(struct net_device *dev)
+{
+ int ret;
+
+ /*
+ * Is it already up?
+ */
+ if (dev->flags & IFF_UP)
+ return 0;
+
+ /*
+ * Open device
+ */
+ ret = __dev_open(dev);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * ... and announce new interface.
+ */
+ rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
+ call_netdevice_notifiers(NETDEV_UP, dev);
+
+ return ret;
+}
+EXPORT_SYMBOL(dev_open);
+
+static int __dev_close(struct net_device *dev)
{
const struct net_device_ops *ops = dev->netdev_ops;
- ASSERT_RTNL();
+ ASSERT_RTNL();
might_sleep();
- if (!(dev->flags & IFF_UP))
- return 0;
-
/*
* Tell people we are going down, so that they can
* prepare to death, when device is still operating.
@@ -1252,14 +1254,34 @@ int dev_close(struct net_device *dev)
dev->flags &= ~IFF_UP;
/*
- * Tell people we are down
+ * Shutdown NET_DMA
*/
- call_netdevice_notifiers(NETDEV_DOWN, dev);
+ net_dmaengine_put();
+
+ return 0;
+}
+
+/**
+ * dev_close - shutdown an interface.
+ * @dev: device to shutdown
+ *
+ * This function moves an active device into down state. A
+ * %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
+ * is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
+ * chain.
+ */
+int dev_close(struct net_device *dev)
+{
+ if (!(dev->flags & IFF_UP))
+ return 0;
+
+ __dev_close(dev);
/*
- * Shutdown NET_DMA
+ * Tell people we are down
*/
- net_dmaengine_put();
+ rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
+ call_netdevice_notifiers(NETDEV_DOWN, dev);
return 0;
}
@@ -4299,18 +4321,10 @@ unsigned dev_get_flags(const struct net_device *dev)
}
EXPORT_SYMBOL(dev_get_flags);
-/**
- * dev_change_flags - change device settings
- * @dev: device
- * @flags: device state flags
- *
- * Change settings on device based state flags. The flags are
- * in the userspace exported format.
- */
-int dev_change_flags(struct net_device *dev, unsigned flags)
+int __dev_change_flags(struct net_device *dev, unsigned int flags)
{
- int ret, changes;
int old_flags = dev->flags;
+ int ret;
ASSERT_RTNL();
@@ -4341,17 +4355,12 @@ int dev_change_flags(struct net_device *dev, unsigned flags)
ret = 0;
if ((old_flags ^ flags) & IFF_UP) { /* Bit is different ? */
- ret = ((old_flags & IFF_UP) ? dev_close : dev_open)(dev);
+ ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
if (!ret)
dev_set_rx_mode(dev);
}
- if (dev->flags & IFF_UP &&
- ((old_flags ^ dev->flags) & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI |
- IFF_VOLATILE)))
- call_netdevice_notifiers(NETDEV_CHANGE, dev);
-
if ((flags ^ dev->gflags) & IFF_PROMISC) {
int inc = (flags & IFF_PROMISC) ? 1 : -1;
@@ -4370,11 +4379,47 @@ int dev_change_flags(struct net_device *dev, unsigned flags)
dev_set_allmulti(dev, inc);
}
- /* Exclude state transition flags, already notified */
- changes = (old_flags ^ dev->flags) & ~(IFF_UP | IFF_RUNNING);
+ return ret;
+}
+
+void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
+{
+ unsigned int changes = dev->flags ^ old_flags;
+
+ if (changes & IFF_UP) {
+ if (dev->flags & IFF_UP)
+ call_netdevice_notifiers(NETDEV_UP, dev);
+ else
+ call_netdevice_notifiers(NETDEV_DOWN, dev);
+ }
+
+ if (dev->flags & IFF_UP &&
+ (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE)))
+ call_netdevice_notifiers(NETDEV_CHANGE, dev);
+}
+
+/**
+ * dev_change_flags - change device settings
+ * @dev: device
+ * @flags: device state flags
+ *
+ * Change settings on device based state flags. The flags are
+ * in the userspace exported format.
+ */
+int dev_change_flags(struct net_device *dev, unsigned flags)
+{
+ int ret, changes;
+ int old_flags = dev->flags;
+
+ ret = __dev_change_flags(dev, flags);
+ if (ret < 0)
+ return ret;
+
+ changes = old_flags ^ dev->flags;
if (changes)
rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
+ __dev_notify_flags(dev, old_flags);
return ret;
}
EXPORT_SYMBOL(dev_change_flags);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 020e43b..c21ec42 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1427,8 +1427,6 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
switch (event) {
case NETDEV_UP:
case NETDEV_DOWN:
- rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
- break;
case NETDEV_PRE_UP:
case NETDEV_POST_INIT:
case NETDEV_REGISTER:
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