[v4 Patch 1/3] netpoll: add generic support for bridge and bonding devices

[v4 Patch 1/3] netpoll: add generic support for bridge and bonding devices

[Amerigo Wang]

V4:
Use "unlikely" to mark netpoll call path, suggested by Stephen.
Handle NETDEV_GOING_DOWN case.

V3:
Update to latest Linus' tree.
Fix deadlocks when releasing slaves of bonding devices.
Thanks to Andy.

V2:
Fix some bugs of previous version.
Remove ->netpoll_setup and ->netpoll_xmit, they are not necessary.
Don't poll all underlying devices, poll ->real_dev in struct netpoll.
Thanks to David for suggesting above.

------------>

This whole patchset is for adding netpoll support to bridge and bonding
devices. I already tested it for bridge, bonding, bridge over bonding,
and bonding over bridge. It looks fine now.


To make bridge and bonding support netpoll, we need to adjust
some netpoll generic code. This patch does the following things:

1) introduce two new priv_flags for struct net_device:
   IFF_IN_NETPOLL which identifies we are processing a netpoll;
   IFF_DISABLE_NETPOLL is used to disable netpoll support for a device
   at run-time;

2) introduce one new method for netdev_ops:
   ->ndo_netpoll_cleanup() is used to clean up netpoll when a device is
     removed.

3) introduce netpoll_poll_dev() which takes a struct net_device * parameter;
   export netpoll_send_skb() and netpoll_poll_dev() which will be used later;

4) hide a pointer to struct netpoll in struct netpoll_info, ditto.

5) introduce ->real_dev for struct netpoll.

6) introduce a new status NETDEV_BONDING_DESLAE, which is used to disable
   netconsole before releasing a slave, to avoid deadlocks.

Cc: David Miller <davem@davemloft.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: WANG Cong <amwang@redhat.com>

---

Index: linux-2.6/include/linux/if.h
===================================================================
--- linux-2.6.orig/include/linux/if.h
+++ linux-2.6/include/linux/if.h
@@ -71,6 +71,8 @@
 					 * release skb->dst
 					 */
 #define IFF_DONT_BRIDGE 0x800		/* disallow bridging this ether dev */
+#define IFF_IN_NETPOLL	0x1000		/* whether we are processing netpoll */
+#define IFF_DISABLE_NETPOLL	0x2000	/* disable netpoll at run-time */
 
 #define IF_GET_IFACE	0x0001		/* for querying only */
 #define IF_GET_PROTO	0x0002
Index: linux-2.6/include/linux/netdevice.h
===================================================================
--- linux-2.6.orig/include/linux/netdevice.h
+++ linux-2.6/include/linux/netdevice.h
@@ -667,6 +667,7 @@ struct net_device_ops {
 						        unsigned short vid);
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	void                    (*ndo_poll_controller)(struct net_device *dev);
+	void			(*ndo_netpoll_cleanup)(struct net_device *dev);
 #endif
 	int			(*ndo_set_vf_mac)(struct net_device *dev,
 						  int queue, u8 *mac);
Index: linux-2.6/include/linux/netpoll.h
===================================================================
--- linux-2.6.orig/include/linux/netpoll.h
+++ linux-2.6/include/linux/netpoll.h
@@ -14,6 +14,7 @@
 
 struct netpoll {
 	struct net_device *dev;
+	struct net_device *real_dev;
 	char dev_name[IFNAMSIZ];
 	const char *name;
 	void (*rx_hook)(struct netpoll *, int, char *, int);
@@ -36,8 +37,11 @@ struct netpoll_info {
 	struct sk_buff_head txq;
 
 	struct delayed_work tx_work;
+
+	struct netpoll *netpoll;
 };
 
+void netpoll_poll_dev(struct net_device *dev);
 void netpoll_poll(struct netpoll *np);
 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
 void netpoll_print_options(struct netpoll *np);
@@ -47,6 +51,7 @@ int netpoll_trap(void);
 void netpoll_set_trap(int trap);
 void netpoll_cleanup(struct netpoll *np);
 int __netpoll_rx(struct sk_buff *skb);
+void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
 
 
 #ifdef CONFIG_NETPOLL
Index: linux-2.6/net/core/netpoll.c
===================================================================
--- linux-2.6.orig/net/core/netpoll.c
+++ linux-2.6/net/core/netpoll.c
@@ -179,9 +179,8 @@ static void service_arp_queue(struct net
 	}
 }
 
-void netpoll_poll(struct netpoll *np)
+void netpoll_poll_dev(struct net_device *dev)
 {
-	struct net_device *dev = np->dev;
 	const struct net_device_ops *ops;
 
 	if (!dev || !netif_running(dev))
@@ -201,6 +200,11 @@ void netpoll_poll(struct netpoll *np)
 	zap_completion_queue();
 }
 
+void netpoll_poll(struct netpoll *np)
+{
+	netpoll_poll_dev(np->dev);
+}
+
 static void refill_skbs(void)
 {
 	struct sk_buff *skb;
@@ -282,7 +286,7 @@ static int netpoll_owner_active(struct n
 	return 0;
 }
 
-static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
+void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 {
 	int status = NETDEV_TX_BUSY;
 	unsigned long tries;
@@ -308,7 +312,9 @@ static void netpoll_send_skb(struct netp
 		     tries > 0; --tries) {
 			if (__netif_tx_trylock(txq)) {
 				if (!netif_tx_queue_stopped(txq)) {
+					dev->priv_flags |= IFF_IN_NETPOLL;
 					status = ops->ndo_start_xmit(skb, dev);
+					dev->priv_flags &= ~IFF_IN_NETPOLL;
 					if (status == NETDEV_TX_OK)
 						txq_trans_update(txq);
 				}
@@ -756,7 +762,10 @@ int netpoll_setup(struct netpoll *np)
 		atomic_inc(&npinfo->refcnt);
 	}
 
-	if (!ndev->netdev_ops->ndo_poll_controller) {
+	npinfo->netpoll = np;
+
+	if (ndev->priv_flags & IFF_DISABLE_NETPOLL
+			|| !ndev->netdev_ops->ndo_poll_controller) {
 		printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
 		       np->name, np->dev_name);
 		err = -ENOTSUPP;
@@ -878,6 +887,7 @@ void netpoll_cleanup(struct netpoll *np)
 			}
 
 			if (atomic_dec_and_test(&npinfo->refcnt)) {
+				const struct net_device_ops *ops;
 				skb_queue_purge(&npinfo->arp_tx);
 				skb_queue_purge(&npinfo->txq);
 				cancel_rearming_delayed_work(&npinfo->tx_work);
@@ -885,7 +895,11 @@ void netpoll_cleanup(struct netpoll *np)
 				/* clean after last, unfinished work */
 				__skb_queue_purge(&npinfo->txq);
 				kfree(npinfo);
-				np->dev->npinfo = NULL;
+				ops = np->dev->netdev_ops;
+				if (ops->ndo_netpoll_cleanup)
+					ops->ndo_netpoll_cleanup(np->dev);
+				else
+					np->dev->npinfo = NULL;
 			}
 		}
 
@@ -908,6 +922,7 @@ void netpoll_set_trap(int trap)
 		atomic_dec(&trapped);
 }
 
+EXPORT_SYMBOL(netpoll_send_skb);
 EXPORT_SYMBOL(netpoll_set_trap);
 EXPORT_SYMBOL(netpoll_trap);
 EXPORT_SYMBOL(netpoll_print_options);
@@ -915,4 +930,5 @@ EXPORT_SYMBOL(netpoll_parse_options);
 EXPORT_SYMBOL(netpoll_setup);
 EXPORT_SYMBOL(netpoll_cleanup);
 EXPORT_SYMBOL(netpoll_send_udp);
+EXPORT_SYMBOL(netpoll_poll_dev);
 EXPORT_SYMBOL(netpoll_poll);
Index: linux-2.6/drivers/net/netconsole.c
===================================================================
--- linux-2.6.orig/drivers/net/netconsole.c
+++ linux-2.6/drivers/net/netconsole.c
@@ -665,7 +665,8 @@ static int netconsole_netdev_event(struc
 	struct netconsole_target *nt;
 	struct net_device *dev = ptr;
 
-	if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER))
+	if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
+	      event == NETDEV_BONDING_DESLAVE || event == NETDEV_GOING_DOWN))
 		goto done;
 
 	spin_lock_irqsave(&target_list_lock, flags);
@@ -677,19 +678,21 @@ static int netconsole_netdev_event(struc
 				strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
 				break;
 			case NETDEV_UNREGISTER:
-				if (!nt->enabled)
-					break;
 				netpoll_cleanup(&nt->np);
+				/* Fall through */
+			case NETDEV_GOING_DOWN:
+			case NETDEV_BONDING_DESLAVE:
 				nt->enabled = 0;
-				printk(KERN_INFO "netconsole: network logging stopped"
-					", interface %s unregistered\n",
-					dev->name);
 				break;
 			}
 		}
 		netconsole_target_put(nt);
 	}
 	spin_unlock_irqrestore(&target_list_lock, flags);
+	if (event == NETDEV_UNREGISTER || event == NETDEV_BONDING_DESLAVE)
+		printk(KERN_INFO "netconsole: network logging stopped, "
+			"interface %s %s\n",  dev->name,
+			event == NETDEV_UNREGISTER ? "unregistered" : "released slaves");
 
 done:
 	return NOTIFY_DONE;
Index: linux-2.6/include/linux/notifier.h
===================================================================
--- linux-2.6.orig/include/linux/notifier.h
+++ linux-2.6/include/linux/notifier.h
@@ -203,6 +203,7 @@ static inline int notifier_to_errno(int 
 #define NETDEV_BONDING_NEWTYPE  0x000F
 #define NETDEV_POST_INIT	0x0010
 #define NETDEV_UNREGISTER_BATCH 0x0011
+#define NETDEV_BONDING_DESLAVE  0x0012
 
 #define SYS_DOWN	0x0001	/* Notify of system down */
 #define SYS_RESTART	SYS_DOWN

[v4 Patch 2/3] bridge: make bridge support netpoll

[Amerigo Wang]

Based on the previous patch, make bridge support netpoll by:

1) implement the 2 methods to support netpoll for bridge;

2) modify netpoll during forwarding packets via bridge;

3) disable netpoll support of bridge when a netpoll-unabled device
   is added to bridge;

4) enable netpoll support when all underlying devices support netpoll.

Cc: David Miller <davem@davemloft.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: WANG Cong <amwang@redhat.com>

---

Index: linux-2.6/net/bridge/br_device.c
===================================================================
--- linux-2.6.orig/net/bridge/br_device.c
+++ linux-2.6/net/bridge/br_device.c
@@ -13,8 +13,10 @@
 
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
+#include <linux/netpoll.h>
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
+#include <linux/list.h>
 
 #include <asm/uaccess.h>
 #include "br_private.h"
@@ -162,6 +164,59 @@ static int br_set_tx_csum(struct net_dev
 	return 0;
 }
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+bool br_devices_support_netpoll(struct net_bridge *br)
+{
+	struct net_bridge_port *p;
+	bool ret = true;
+	int count = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&br->lock, flags);
+	list_for_each_entry(p, &br->port_list, list) {
+		count++;
+		if (p->dev->priv_flags & IFF_DISABLE_NETPOLL
+				|| !p->dev->netdev_ops->ndo_poll_controller)
+			ret = false;
+	}
+	spin_unlock_irqrestore(&br->lock, flags);
+	return count != 0 && ret;
+}
+
+static void br_poll_controller(struct net_device *br_dev)
+{
+	struct netpoll *np = br_dev->npinfo->netpoll;
+
+	if (np->real_dev != br_dev)
+		netpoll_poll_dev(np->real_dev);
+}
+
+void br_netpoll_cleanup(struct net_device *br_dev)
+{
+	struct net_bridge *br = netdev_priv(br_dev);
+	struct net_bridge_port *p, *n;
+	const struct net_device_ops *ops;
+
+	br->dev->npinfo = NULL;
+	list_for_each_entry_safe(p, n, &br->port_list, list) {
+		if (p->dev) {
+			ops = p->dev->netdev_ops;
+			if (ops->ndo_netpoll_cleanup)
+				ops->ndo_netpoll_cleanup(p->dev);
+			else
+				p->dev->npinfo = NULL;
+		}
+	}
+}
+
+#else
+
+void br_netpoll_cleanup(struct net_device *br_dev)
+{
+}
+
+#endif
+
 static const struct ethtool_ops br_ethtool_ops = {
 	.get_drvinfo    = br_getinfo,
 	.get_link	= ethtool_op_get_link,
@@ -184,6 +239,10 @@ static const struct net_device_ops br_ne
 	.ndo_set_multicast_list	 = br_dev_set_multicast_list,
 	.ndo_change_mtu		 = br_change_mtu,
 	.ndo_do_ioctl		 = br_dev_ioctl,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_netpoll_cleanup	 = br_netpoll_cleanup,
+	.ndo_poll_controller	 = br_poll_controller,
+#endif
 };
 
 void br_dev_setup(struct net_device *dev)
Index: linux-2.6/net/bridge/br_forward.c
===================================================================
--- linux-2.6.orig/net/bridge/br_forward.c
+++ linux-2.6/net/bridge/br_forward.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
+#include <linux/netpoll.h>
 #include <linux/skbuff.h>
 #include <linux/if_vlan.h>
 #include <linux/netfilter_bridge.h>
@@ -50,7 +51,13 @@ int br_dev_queue_push_xmit(struct sk_buf
 		else {
 			skb_push(skb, ETH_HLEN);
 
-			dev_queue_xmit(skb);
+#ifdef CONFIG_NET_POLL_CONTROLLER
+			if (unlikely(skb->dev->priv_flags & IFF_IN_NETPOLL)) {
+				netpoll_send_skb(skb->dev->npinfo->netpoll, skb);
+				skb->dev->priv_flags &= ~IFF_IN_NETPOLL;
+			} else
+#endif
+				dev_queue_xmit(skb);
 		}
 	}
 
@@ -66,9 +73,23 @@ int br_forward_finish(struct sk_buff *sk
 
 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
 {
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	struct net_bridge *br = to->br;
+	if (unlikely(br->dev->priv_flags & IFF_IN_NETPOLL)) {
+		struct netpoll *np;
+		to->dev->npinfo = skb->dev->npinfo;
+		np = skb->dev->npinfo->netpoll;
+		np->real_dev = np->dev = to->dev;
+		to->dev->priv_flags |= IFF_IN_NETPOLL;
+	}
+#endif
 	skb->dev = to->dev;
 	NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
 			br_forward_finish);
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (skb->dev->npinfo)
+		skb->dev->npinfo->netpoll->dev = br->dev;
+#endif
 }
 
 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
Index: linux-2.6/net/bridge/br_if.c
===================================================================
--- linux-2.6.orig/net/bridge/br_if.c
+++ linux-2.6/net/bridge/br_if.c
@@ -13,6 +13,7 @@
 
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
+#include <linux/netpoll.h>
 #include <linux/ethtool.h>
 #include <linux/if_arp.h>
 #include <linux/module.h>
@@ -153,6 +154,14 @@ static void del_nbp(struct net_bridge_po
 	kobject_uevent(&p->kobj, KOBJ_REMOVE);
 	kobject_del(&p->kobj);
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (br_devices_support_netpoll(br))
+		br->dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
+	if (dev->netdev_ops->ndo_netpoll_cleanup)
+		dev->netdev_ops->ndo_netpoll_cleanup(dev);
+	else
+		dev->npinfo = NULL;
+#endif
 	call_rcu(&p->rcu, destroy_nbp_rcu);
 }
 
@@ -165,6 +174,8 @@ static void del_br(struct net_bridge *br
 		del_nbp(p);
 	}
 
+	br_netpoll_cleanup(br->dev);
+
 	del_timer_sync(&br->gc_timer);
 
 	br_sysfs_delbr(br->dev);
@@ -438,6 +449,20 @@ int br_add_if(struct net_bridge *br, str
 
 	kobject_uevent(&p->kobj, KOBJ_ADD);
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (br_devices_support_netpoll(br)) {
+		br->dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
+		if (br->dev->npinfo)
+			dev->npinfo = br->dev->npinfo;
+	} else if (!(br->dev->priv_flags & IFF_DISABLE_NETPOLL)) {
+		br->dev->priv_flags |= IFF_DISABLE_NETPOLL;
+		printk(KERN_INFO "New device %s does not support netpoll\n",
+			dev->name);
+		printk(KERN_INFO "Disabling netpoll for %s\n",
+			br->dev->name);
+	}
+#endif
+
 	return 0;
 err2:
 	br_fdb_delete_by_port(br, p, 1);
Index: linux-2.6/net/bridge/br_private.h
===================================================================
--- linux-2.6.orig/net/bridge/br_private.h
+++ linux-2.6/net/bridge/br_private.h
@@ -233,6 +233,8 @@ static inline int br_is_root_bridge(cons
 extern void br_dev_setup(struct net_device *dev);
 extern netdev_tx_t br_dev_xmit(struct sk_buff *skb,
 			       struct net_device *dev);
+extern bool br_devices_support_netpoll(struct net_bridge *br);
+extern void br_netpoll_cleanup(struct net_device *br_dev);
 
 /* br_fdb.c */
 extern int br_fdb_init(void);

[v4 Patch 3/3] bonding: make bonding support netpoll

[Amerigo Wang]

Based on Andy's work, but I modified a lot.

Similar to the patch for bridge, this patch does:

1) implement the 2 methods to support netpoll for bonding;

2) modify netpoll during forwarding packets via bonding;

3) disable netpoll support of bonding when a netpoll-unabled device
   is added to bonding;

4) enable netpoll support when all underlying devices support netpoll.

Cc: Andy Gospodarek <gospo@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: WANG Cong <amwang@redhat.com>

---

Index: linux-2.6/drivers/net/bonding/bond_main.c
===================================================================
--- linux-2.6.orig/drivers/net/bonding/bond_main.c
+++ linux-2.6/drivers/net/bonding/bond_main.c
@@ -59,6 +59,7 @@
 #include <linux/uaccess.h>
 #include <linux/errno.h>
 #include <linux/netdevice.h>
+#include <linux/netpoll.h>
 #include <linux/inetdevice.h>
 #include <linux/igmp.h>
 #include <linux/etherdevice.h>
@@ -430,7 +431,18 @@ int bond_dev_queue_xmit(struct bonding *
 	}
 
 	skb->priority = 1;
-	dev_queue_xmit(skb);
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (unlikely(bond->dev->priv_flags & IFF_IN_NETPOLL)) {
+		struct netpoll *np = bond->dev->npinfo->netpoll;
+		slave_dev->npinfo = bond->dev->npinfo;
+		np->real_dev = np->dev = skb->dev;
+		slave_dev->priv_flags |= IFF_IN_NETPOLL;
+		netpoll_send_skb(np, skb);
+		slave_dev->priv_flags &= ~IFF_IN_NETPOLL;
+		np->dev = bond->dev;
+	} else
+#endif
+		dev_queue_xmit(skb);
 
 	return 0;
 }
@@ -1329,6 +1341,61 @@ static void bond_detach_slave(struct bon
 	bond->slave_cnt--;
 }
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+/*
+ * You must hold read lock on bond->lock before calling this.
+ */
+static bool slaves_support_netpoll(struct net_device *bond_dev)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	struct slave *slave;
+	int i = 0;
+	bool ret = true;
+
+	bond_for_each_slave(bond, slave, i) {
+		if ((slave->dev->priv_flags & IFF_DISABLE_NETPOLL)
+				|| !slave->dev->netdev_ops->ndo_poll_controller)
+			ret = false;
+	}
+	return i != 0 && ret;
+}
+
+static void bond_poll_controller(struct net_device *bond_dev)
+{
+	struct net_device *dev = bond_dev->npinfo->netpoll->real_dev;
+	if (dev != bond_dev)
+		netpoll_poll_dev(dev);
+}
+
+static void bond_netpoll_cleanup(struct net_device *bond_dev)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	struct slave *slave;
+	const struct net_device_ops *ops;
+	int i;
+
+	read_lock(&bond->lock);
+	bond_dev->npinfo = NULL;
+	bond_for_each_slave(bond, slave, i) {
+		if (slave->dev) {
+			ops = slave->dev->netdev_ops;
+			if (ops->ndo_netpoll_cleanup)
+				ops->ndo_netpoll_cleanup(slave->dev);
+			else
+				slave->dev->npinfo = NULL;
+		}
+	}
+	read_unlock(&bond->lock);
+}
+
+#else
+
+static void bond_netpoll_cleanup(struct net_device *bond_dev)
+{
+}
+
+#endif
+
 /*---------------------------------- IOCTL ----------------------------------*/
 
 static int bond_sethwaddr(struct net_device *bond_dev,
@@ -1735,6 +1802,18 @@ int bond_enslave(struct net_device *bond
 
 	bond_set_carrier(bond);
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (slaves_support_netpoll(bond_dev)) {
+		bond_dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
+		if (bond_dev->npinfo)
+			slave_dev->npinfo = bond_dev->npinfo;
+	} else if (!(bond_dev->priv_flags & IFF_DISABLE_NETPOLL)) {
+		bond_dev->priv_flags |= IFF_DISABLE_NETPOLL;
+		pr_info("New slave device %s does not support netpoll\n",
+			slave_dev->name);
+		pr_info("Disabling netpoll support for %s\n", bond_dev->name);
+	}
+#endif
 	read_unlock(&bond->lock);
 
 	res = bond_create_slave_symlinks(bond_dev, slave_dev);
@@ -1801,6 +1880,7 @@ int bond_release(struct net_device *bond
 		return -EINVAL;
 	}
 
+	netdev_bonding_change(bond_dev, NETDEV_BONDING_DESLAVE);
 	write_lock_bh(&bond->lock);
 
 	slave = bond_get_slave_by_dev(bond, slave_dev);
@@ -1929,6 +2009,17 @@ int bond_release(struct net_device *bond
 
 	netdev_set_master(slave_dev, NULL);
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	read_lock_bh(&bond->lock);
+	if (slaves_support_netpoll(bond_dev))
+		bond_dev->priv_flags &= ~IFF_DISABLE_NETPOLL;
+	read_unlock_bh(&bond->lock);
+	if (slave_dev->netdev_ops->ndo_netpoll_cleanup)
+		slave_dev->netdev_ops->ndo_netpoll_cleanup(slave_dev);
+	else
+		slave_dev->npinfo = NULL;
+#endif
+
 	/* close slave before restoring its mac address */
 	dev_close(slave_dev);
 
@@ -4448,6 +4539,10 @@ static const struct net_device_ops bond_
 	.ndo_vlan_rx_register	= bond_vlan_rx_register,
 	.ndo_vlan_rx_add_vid 	= bond_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= bond_vlan_rx_kill_vid,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_netpoll_cleanup	= bond_netpoll_cleanup,
+	.ndo_poll_controller	= bond_poll_controller,
+#endif
 };
 
 static void bond_destructor(struct net_device *bond_dev)
@@ -4541,6 +4636,8 @@ static void bond_uninit(struct net_devic
 {
 	struct bonding *bond = netdev_priv(bond_dev);
 
+	bond_netpoll_cleanup(bond_dev);
+
 	/* Release the bonded slaves */
 	bond_release_all(bond_dev);
 

Re: [v4 Patch 1/3] netpoll: add generic support for bridge and bonding devices

[David Miller]

From: Amerigo Wang <amwang@redhat.com>
Date: Tue, 27 Apr 2010 03:55:41 -0400

> +	if (ndev->priv_flags & IFF_DISABLE_NETPOLL
> +			|| !ndev->netdev_ops->ndo_poll_controller) {

" ||" goes on first line, not second, and second line needs to be indented
properly so that "!ndev->..." matches up with "ndev->priv_flags ..." on
the previous line.

Re: [v4 Patch 2/3] bridge: make bridge support netpoll

[David Miller]

From: Amerigo Wang <amwang@redhat.com>
Date: Tue, 27 Apr 2010 03:55:56 -0400

> +		if (p->dev->priv_flags & IFF_DISABLE_NETPOLL
> +				|| !p->dev->netdev_ops->ndo_poll_controller)

"||" goes on first line, and indentation on second line is incorrect.
See my comments from patch #1.

Re: [v4 Patch 3/3] bonding: make bonding support netpoll

[David Miller]

From: Amerigo Wang <amwang@redhat.com>
Date: Tue, 27 Apr 2010 03:56:09 -0400

> +		if ((slave->dev->priv_flags & IFF_DISABLE_NETPOLL)
> +				|| !slave->dev->netdev_ops->ndo_poll_controller)

"|| on first line please, plus fix second line's indentation as per
comments given in patch #1 and #2

Re: [v4 Patch 3/3] bonding: make bonding support netpoll

[Cong Wang]

David Miller wrote:
> From: Amerigo Wang <amwang@redhat.com>
> Date: Tue, 27 Apr 2010 03:56:09 -0400
> 
>> +		if ((slave->dev->priv_flags & IFF_DISABLE_NETPOLL)
>> +				|| !slave->dev->netdev_ops->ndo_poll_controller)
> 
> "|| on first line please, plus fix second line's indentation as per
> comments given in patch #1 and #2

Thanks, David!
I will fix all of this style problem.

Re: [v4 Patch 1/3] netpoll: add generic support for bridge and bonding devices

[Dongdong Deng]

On Tue, Apr 27, 2010 at 3:55 PM, Amerigo Wang <amwang@redhat.com> wrote:
> V4:
> Use "unlikely" to mark netpoll call path, suggested by Stephen.
> Handle NETDEV_GOING_DOWN case.
>
> V3:
> Update to latest Linus' tree.
> Fix deadlocks when releasing slaves of bonding devices.
> Thanks to Andy.
>
> V2:
> Fix some bugs of previous version.
> Remove ->netpoll_setup and ->netpoll_xmit, they are not necessary.
> Don't poll all underlying devices, poll ->real_dev in struct netpoll.
> Thanks to David for suggesting above.
>
> ------------>
>
> This whole patchset is for adding netpoll support to bridge and bonding
> devices. I already tested it for bridge, bonding, bridge over bonding,
> and bonding over bridge. It looks fine now.
>
>
> To make bridge and bonding support netpoll, we need to adjust
> some netpoll generic code. This patch does the following things:
>
> 1) introduce two new priv_flags for struct net_device:
>   IFF_IN_NETPOLL which identifies we are processing a netpoll;
>   IFF_DISABLE_NETPOLL is used to disable netpoll support for a device
>   at run-time;
>
> 2) introduce one new method for netdev_ops:
>   ->ndo_netpoll_cleanup() is used to clean up netpoll when a device is
>     removed.
>
> 3) introduce netpoll_poll_dev() which takes a struct net_device * parameter;
>   export netpoll_send_skb() and netpoll_poll_dev() which will be used later;
>
> 4) hide a pointer to struct netpoll in struct netpoll_info, ditto.
>
> 5) introduce ->real_dev for struct netpoll.
>
> 6) introduce a new status NETDEV_BONDING_DESLAE, which is used to disable
>   netconsole before releasing a slave, to avoid deadlocks.
>
> Cc: David Miller <davem@davemloft.net>
> Cc: Neil Horman <nhorman@tuxdriver.com>
> Signed-off-by: WANG Cong <amwang@redhat.com>
>
> ---
>
> Index: linux-2.6/include/linux/if.h
> ===================================================================
> --- linux-2.6.orig/include/linux/if.h
> +++ linux-2.6/include/linux/if.h
> @@ -71,6 +71,8 @@
>                                         * release skb->dst
>                                         */
>  #define IFF_DONT_BRIDGE 0x800          /* disallow bridging this ether dev */
> +#define IFF_IN_NETPOLL 0x1000          /* whether we are processing netpoll */
> +#define IFF_DISABLE_NETPOLL    0x2000  /* disable netpoll at run-time */
>
>  #define IF_GET_IFACE   0x0001          /* for querying only */
>  #define IF_GET_PROTO   0x0002
> Index: linux-2.6/include/linux/netdevice.h
> ===================================================================
> --- linux-2.6.orig/include/linux/netdevice.h
> +++ linux-2.6/include/linux/netdevice.h
> @@ -667,6 +667,7 @@ struct net_device_ops {
>                                                        unsigned short vid);
>  #ifdef CONFIG_NET_POLL_CONTROLLER
>        void                    (*ndo_poll_controller)(struct net_device *dev);
> +       void                    (*ndo_netpoll_cleanup)(struct net_device *dev);
>  #endif
>        int                     (*ndo_set_vf_mac)(struct net_device *dev,
>                                                  int queue, u8 *mac);
> Index: linux-2.6/include/linux/netpoll.h
> ===================================================================
> --- linux-2.6.orig/include/linux/netpoll.h
> +++ linux-2.6/include/linux/netpoll.h
> @@ -14,6 +14,7 @@
>
>  struct netpoll {
>        struct net_device *dev;
> +       struct net_device *real_dev;
>        char dev_name[IFNAMSIZ];
>        const char *name;
>        void (*rx_hook)(struct netpoll *, int, char *, int);
> @@ -36,8 +37,11 @@ struct netpoll_info {
>        struct sk_buff_head txq;
>
>        struct delayed_work tx_work;
> +
> +       struct netpoll *netpoll;
>  };
>
> +void netpoll_poll_dev(struct net_device *dev);
>  void netpoll_poll(struct netpoll *np);
>  void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
>  void netpoll_print_options(struct netpoll *np);
> @@ -47,6 +51,7 @@ int netpoll_trap(void);
>  void netpoll_set_trap(int trap);
>  void netpoll_cleanup(struct netpoll *np);
>  int __netpoll_rx(struct sk_buff *skb);
> +void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
>
>
>  #ifdef CONFIG_NETPOLL
> Index: linux-2.6/net/core/netpoll.c
> ===================================================================
> --- linux-2.6.orig/net/core/netpoll.c
> +++ linux-2.6/net/core/netpoll.c
> @@ -179,9 +179,8 @@ static void service_arp_queue(struct net
>        }
>  }
>
> -void netpoll_poll(struct netpoll *np)
> +void netpoll_poll_dev(struct net_device *dev)
>  {
> -       struct net_device *dev = np->dev;
>        const struct net_device_ops *ops;
>
>        if (!dev || !netif_running(dev))
> @@ -201,6 +200,11 @@ void netpoll_poll(struct netpoll *np)
>        zap_completion_queue();
>  }
>
> +void netpoll_poll(struct netpoll *np)
> +{
> +       netpoll_poll_dev(np->dev);
> +}
> +
>  static void refill_skbs(void)
>  {
>        struct sk_buff *skb;
> @@ -282,7 +286,7 @@ static int netpoll_owner_active(struct n
>        return 0;
>  }
>
> -static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
> +void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
>  {
>        int status = NETDEV_TX_BUSY;
>        unsigned long tries;
> @@ -308,7 +312,9 @@ static void netpoll_send_skb(struct netp
>                     tries > 0; --tries) {
>                        if (__netif_tx_trylock(txq)) {
>                                if (!netif_tx_queue_stopped(txq)) {
> +                                       dev->priv_flags |= IFF_IN_NETPOLL;
>                                        status = ops->ndo_start_xmit(skb, dev);
> +                                       dev->priv_flags &= ~IFF_IN_NETPOLL;
>                                        if (status == NETDEV_TX_OK)
>                                                txq_trans_update(txq);
>                                }
> @@ -756,7 +762,10 @@ int netpoll_setup(struct netpoll *np)
>                atomic_inc(&npinfo->refcnt);
>        }
>
> -       if (!ndev->netdev_ops->ndo_poll_controller) {
> +       npinfo->netpoll = np;
> +
> +       if (ndev->priv_flags & IFF_DISABLE_NETPOLL
> +                       || !ndev->netdev_ops->ndo_poll_controller) {
>                printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
>                       np->name, np->dev_name);
>                err = -ENOTSUPP;
> @@ -878,6 +887,7 @@ void netpoll_cleanup(struct netpoll *np)
>                        }
>
>                        if (atomic_dec_and_test(&npinfo->refcnt)) {
> +                               const struct net_device_ops *ops;
>                                skb_queue_purge(&npinfo->arp_tx);
>                                skb_queue_purge(&npinfo->txq);
>                                cancel_rearming_delayed_work(&npinfo->tx_work);
> @@ -885,7 +895,11 @@ void netpoll_cleanup(struct netpoll *np)
>                                /* clean after last, unfinished work */
>                                __skb_queue_purge(&npinfo->txq);
>                                kfree(npinfo);
> -                               np->dev->npinfo = NULL;
> +                               ops = np->dev->netdev_ops;
> +                               if (ops->ndo_netpoll_cleanup)
> +                                       ops->ndo_netpoll_cleanup(np->dev);
> +                               else
> +                                       np->dev->npinfo = NULL;


+             if (ops->ndo_netpoll_cleanup)
+                                       ops->ndo_netpoll_cleanup(np->dev);
+             np->dev->npinfo = NULL;

I think it is good to set np->dev->npinfo to NULL  even though we have
the netpoll_cleanup opt.

Regards
Dongdong

>                        }
>                }
>
> @@ -908,6 +922,7 @@ void netpoll_set_trap(int trap)
>                atomic_dec(&trapped);
>  }
>
> +EXPORT_SYMBOL(netpoll_send_skb);
>  EXPORT_SYMBOL(netpoll_set_trap);
>  EXPORT_SYMBOL(netpoll_trap);
>  EXPORT_SYMBOL(netpoll_print_options);
> @@ -915,4 +930,5 @@ EXPORT_SYMBOL(netpoll_parse_options);
>  EXPORT_SYMBOL(netpoll_setup);
>  EXPORT_SYMBOL(netpoll_cleanup);
>  EXPORT_SYMBOL(netpoll_send_udp);
> +EXPORT_SYMBOL(netpoll_poll_dev);
>  EXPORT_SYMBOL(netpoll_poll);
> Index: linux-2.6/drivers/net/netconsole.c
> ===================================================================
> --- linux-2.6.orig/drivers/net/netconsole.c
> +++ linux-2.6/drivers/net/netconsole.c
> @@ -665,7 +665,8 @@ static int netconsole_netdev_event(struc
>        struct netconsole_target *nt;
>        struct net_device *dev = ptr;
>
> -       if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER))
> +       if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
> +             event == NETDEV_BONDING_DESLAVE || event == NETDEV_GOING_DOWN))
>                goto done;
>
>        spin_lock_irqsave(&target_list_lock, flags);
> @@ -677,19 +678,21 @@ static int netconsole_netdev_event(struc
>                                strlcpy(nt->np.dev_name, dev->name, IFNAMSIZ);
>                                break;
>                        case NETDEV_UNREGISTER:
> -                               if (!nt->enabled)
> -                                       break;
>                                netpoll_cleanup(&nt->np);
> +                               /* Fall through */
> +                       case NETDEV_GOING_DOWN:
> +                       case NETDEV_BONDING_DESLAVE:
>                                nt->enabled = 0;
> -                               printk(KERN_INFO "netconsole: network logging stopped"
> -                                       ", interface %s unregistered\n",
> -                                       dev->name);
>                                break;
>                        }
>                }
>                netconsole_target_put(nt);
>        }
>        spin_unlock_irqrestore(&target_list_lock, flags);
> +       if (event == NETDEV_UNREGISTER || event == NETDEV_BONDING_DESLAVE)
> +               printk(KERN_INFO "netconsole: network logging stopped, "
> +                       "interface %s %s\n",  dev->name,
> +                       event == NETDEV_UNREGISTER ? "unregistered" : "released slaves");
>
>  done:
>        return NOTIFY_DONE;
> Index: linux-2.6/include/linux/notifier.h
> ===================================================================
> --- linux-2.6.orig/include/linux/notifier.h
> +++ linux-2.6/include/linux/notifier.h
> @@ -203,6 +203,7 @@ static inline int notifier_to_errno(int
>  #define NETDEV_BONDING_NEWTYPE  0x000F
>  #define NETDEV_POST_INIT       0x0010
>  #define NETDEV_UNREGISTER_BATCH 0x0011
> +#define NETDEV_BONDING_DESLAVE  0x0012
>
>  #define SYS_DOWN       0x0001  /* Notify of system down */
>  #define SYS_RESTART    SYS_DOWN
> --
> 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/
>

Re: [v4 Patch 1/3] netpoll: add generic support for bridge and bonding devices

[Cong Wang]

Dongdong Deng wrote:
> 
> 
> +             if (ops->ndo_netpoll_cleanup)
> +                                       ops->ndo_netpoll_cleanup(np->dev);
> +             np->dev->npinfo = NULL;
> 
> I think it is good to set np->dev->npinfo to NULL  even though we have
> the netpoll_cleanup opt.
> 

This is redundant, since ->ndo_netpoll_cleanup will set it.

Thanks.