[PATCH v4 00/14] some netpoll and netconsole fixes

[PATCH v4 00/14] some netpoll and netconsole fixes

[Cong Wang]

V4:
* rebase against net tree
* fix a compile error in patch 9
* update patch 7 as Stephen suggested

V3:
* add more patches
* update patch 7 as David suggested

V2:
* update patch 1/8 as Eric suggested
* drop the bridge patch, add comments instead
* add patch 8/8

This patchset fixes serval problems in netconsole and netpoll.

I ran this patch in my KVM guest with some netpoll test cases,
even covered with some corner cases, everything worked as expected.

BTW, my kernel config enables the following validatation options:

CONFIG_DEBUG_ATOMIC_SLEEP=y
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU=y
CONFIG_LOCKDEP=y
CONFIG_RCU_CPU_STALL_TIMEOUT=60
CONFIG_LOCKUP_DETECTOR=y
CONFIG_HARDLOCKUP_DETECTOR=y

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>

--------

 netpoll: use GFP_ATOMIC in slave_enable_netpoll() and
 netpoll: make __netpoll_cleanup non-block
 netconsole: do not release spin_lock when calling
 netpoll: take rcu_read_lock_bh() in netpoll_rx()
 netpoll: use netpoll_rx_on() in netpoll_rx()
 netpoll: take rcu_read_lock_bh() in
 bridge: add some comments for NETDEV_RELEASE
 bridge: use list_for_each_entry() in netpoll functions
 netpoll: check netpoll tx status on the right device
 netpoll: convert several functions to bool
 vlan: clean up vlan_dev_hard_start_xmit()
 netpoll: handle vlan tags in netpoll tx and rx path
 netpoll: re-enable irq in poll_napi()
 netconsole.txt: revision of examples for the receiver

 Documentation/networking/netconsole.txt |   19 +++++-
 drivers/net/bonding/bond_main.c         |   12 ++--
 drivers/net/netconsole.c                |    5 --
 drivers/net/team/team.c                 |   16 +++--
 include/linux/if_team.h                 |   30 ++++----
 include/linux/netdevice.h               |    3 +-
 include/linux/netpoll.h                 |   42 +++++++-----
 net/8021q/vlan_dev.c                    |   40 +++++++----
 net/bridge/br_device.c                  |   27 +++-----
 net/bridge/br_forward.c                 |    2 +-
 net/bridge/br_if.c                      |    6 ++-
 net/bridge/br_private.h                 |    4 +-
 net/core/netpoll.c                      |  109 ++++++++++++++++++++++---------
 13 files changed, 194 insertions(+), 121 deletions(-)

[PATCH 01/14] netpoll: use GFP_ATOMIC in slave_enable_netpoll() and __netpoll_setup()

[Cong Wang]

slave_enable_netpoll() and __netpoll_setup() may be called
with read_lock() held, so should use GFP_ATOMIC to allocate
memory. Eric suggested to pass gfp flags to __netpoll_setup().

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 drivers/net/bonding/bond_main.c |    6 +++---
 drivers/net/team/team.c         |   16 +++++++++-------
 include/linux/netdevice.h       |    3 ++-
 include/linux/netpoll.h         |    2 +-
 net/8021q/vlan_dev.c            |    7 ++++---
 net/bridge/br_device.c          |   12 ++++++------
 net/bridge/br_if.c              |    2 +-
 net/bridge/br_private.h         |    4 ++--
 net/core/netpoll.c              |    8 ++++----
 9 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 6fae5f3..8697136 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1235,12 +1235,12 @@ static inline int slave_enable_netpoll(struct slave *slave)
 	struct netpoll *np;
 	int err = 0;
 
-	np = kzalloc(sizeof(*np), GFP_KERNEL);
+	np = kzalloc(sizeof(*np), GFP_ATOMIC);
 	err = -ENOMEM;
 	if (!np)
 		goto out;
 
-	err = __netpoll_setup(np, slave->dev);
+	err = __netpoll_setup(np, slave->dev, GFP_ATOMIC);
 	if (err) {
 		kfree(np);
 		goto out;
@@ -1292,7 +1292,7 @@ static void bond_netpoll_cleanup(struct net_device *bond_dev)
 	read_unlock(&bond->lock);
 }
 
-static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
+static int bond_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, gfp_t gfp)
 {
 	struct bonding *bond = netdev_priv(dev);
 	struct slave *slave;
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 87707ab..341b65d 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -795,16 +795,17 @@ static void team_port_leave(struct team *team, struct team_port *port)
 }
 
 #ifdef CONFIG_NET_POLL_CONTROLLER
-static int team_port_enable_netpoll(struct team *team, struct team_port *port)
+static int team_port_enable_netpoll(struct team *team, struct team_port *port,
+				    gfp_t gfp)
 {
 	struct netpoll *np;
 	int err;
 
-	np = kzalloc(sizeof(*np), GFP_KERNEL);
+	np = kzalloc(sizeof(*np), gfp);
 	if (!np)
 		return -ENOMEM;
 
-	err = __netpoll_setup(np, port->dev);
+	err = __netpoll_setup(np, port->dev, gfp);
 	if (err) {
 		kfree(np);
 		return err;
@@ -833,7 +834,8 @@ static struct netpoll_info *team_netpoll_info(struct team *team)
 }
 
 #else
-static int team_port_enable_netpoll(struct team *team, struct team_port *port)
+static int team_port_enable_netpoll(struct team *team, struct team_port *port,
+				    gfp_t gfp)
 {
 	return 0;
 }
@@ -913,7 +915,7 @@ static int team_port_add(struct team *team, struct net_device *port_dev)
 	}
 
 	if (team_netpoll_info(team)) {
-		err = team_port_enable_netpoll(team, port);
+		err = team_port_enable_netpoll(team, port, GFP_KERNEL);
 		if (err) {
 			netdev_err(dev, "Failed to enable netpoll on device %s\n",
 				   portname);
@@ -1443,7 +1445,7 @@ static void team_netpoll_cleanup(struct net_device *dev)
 }
 
 static int team_netpoll_setup(struct net_device *dev,
-			      struct netpoll_info *npifo)
+			      struct netpoll_info *npifo, gfp_t gfp)
 {
 	struct team *team = netdev_priv(dev);
 	struct team_port *port;
@@ -1451,7 +1453,7 @@ static int team_netpoll_setup(struct net_device *dev,
 
 	mutex_lock(&team->lock);
 	list_for_each_entry(port, &team->port_list, list) {
-		err = team_port_enable_netpoll(team, port);
+		err = team_port_enable_netpoll(team, port, gfp);
 		if (err) {
 			__team_netpoll_cleanup(team);
 			break;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a9db4f3..3560d68 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -953,7 +953,8 @@ struct net_device_ops {
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	void                    (*ndo_poll_controller)(struct net_device *dev);
 	int			(*ndo_netpoll_setup)(struct net_device *dev,
-						     struct netpoll_info *info);
+						     struct netpoll_info *info,
+						     gfp_t gfp);
 	void			(*ndo_netpoll_cleanup)(struct net_device *dev);
 #endif
 	int			(*ndo_set_vf_mac)(struct net_device *dev,
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 28f5389..bf2d51e 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -43,7 +43,7 @@ struct netpoll_info {
 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
 void netpoll_print_options(struct netpoll *np);
 int netpoll_parse_options(struct netpoll *np, char *opt);
-int __netpoll_setup(struct netpoll *np, struct net_device *ndev);
+int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp);
 int netpoll_setup(struct netpoll *np);
 int netpoll_trap(void);
 void netpoll_set_trap(int trap);
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 73a2a83..ee4ae09 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -669,19 +669,20 @@ static void vlan_dev_poll_controller(struct net_device *dev)
 	return;
 }
 
-static int vlan_dev_netpoll_setup(struct net_device *dev, struct netpoll_info *npinfo)
+static int vlan_dev_netpoll_setup(struct net_device *dev, struct netpoll_info *npinfo,
+				  gfp_t gfp)
 {
 	struct vlan_dev_priv *info = vlan_dev_priv(dev);
 	struct net_device *real_dev = info->real_dev;
 	struct netpoll *netpoll;
 	int err = 0;
 
-	netpoll = kzalloc(sizeof(*netpoll), GFP_KERNEL);
+	netpoll = kzalloc(sizeof(*netpoll), gfp);
 	err = -ENOMEM;
 	if (!netpoll)
 		goto out;
 
-	err = __netpoll_setup(netpoll, real_dev);
+	err = __netpoll_setup(netpoll, real_dev, gfp);
 	if (err) {
 		kfree(netpoll);
 		goto out;
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 3334845..ed0e0f9 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -213,7 +213,8 @@ static void br_netpoll_cleanup(struct net_device *dev)
 	}
 }
 
-static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
+static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
+			    gfp_t gfp)
 {
 	struct net_bridge *br = netdev_priv(dev);
 	struct net_bridge_port *p, *n;
@@ -222,8 +223,7 @@ static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 	list_for_each_entry_safe(p, n, &br->port_list, list) {
 		if (!p->dev)
 			continue;
-
-		err = br_netpoll_enable(p);
+		err = br_netpoll_enable(p, gfp);
 		if (err)
 			goto fail;
 	}
@@ -236,17 +236,17 @@ fail:
 	goto out;
 }
 
-int br_netpoll_enable(struct net_bridge_port *p)
+int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
 {
 	struct netpoll *np;
 	int err = 0;
 
-	np = kzalloc(sizeof(*p->np), GFP_KERNEL);
+	np = kzalloc(sizeof(*p->np), gfp);
 	err = -ENOMEM;
 	if (!np)
 		goto out;
 
-	err = __netpoll_setup(np, p->dev);
+	err = __netpoll_setup(np, p->dev, gfp);
 	if (err) {
 		kfree(np);
 		goto out;
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index e1144e1..171fd6b 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -361,7 +361,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
 	if (err)
 		goto err2;
 
-	if (br_netpoll_info(br) && ((err = br_netpoll_enable(p))))
+	if (br_netpoll_info(br) && ((err = br_netpoll_enable(p, GFP_KERNEL))))
 		goto err3;
 
 	err = netdev_set_master(dev, br->dev);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index a768b24..f507d2a 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -316,7 +316,7 @@ static inline void br_netpoll_send_skb(const struct net_bridge_port *p,
 		netpoll_send_skb(np, skb);
 }
 
-extern int br_netpoll_enable(struct net_bridge_port *p);
+extern int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp);
 extern void br_netpoll_disable(struct net_bridge_port *p);
 #else
 static inline struct netpoll_info *br_netpoll_info(struct net_bridge *br)
@@ -329,7 +329,7 @@ static inline void br_netpoll_send_skb(const struct net_bridge_port *p,
 {
 }
 
-static inline int br_netpoll_enable(struct net_bridge_port *p)
+static inline int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
 {
 	return 0;
 }
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index b4c90e4..37cc854 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -715,7 +715,7 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
 }
 EXPORT_SYMBOL(netpoll_parse_options);
 
-int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
+int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
 {
 	struct netpoll_info *npinfo;
 	const struct net_device_ops *ops;
@@ -734,7 +734,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
 	}
 
 	if (!ndev->npinfo) {
-		npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
+		npinfo = kmalloc(sizeof(*npinfo), gfp);
 		if (!npinfo) {
 			err = -ENOMEM;
 			goto out;
@@ -752,7 +752,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
 
 		ops = np->dev->netdev_ops;
 		if (ops->ndo_netpoll_setup) {
-			err = ops->ndo_netpoll_setup(ndev, npinfo);
+			err = ops->ndo_netpoll_setup(ndev, npinfo, gfp);
 			if (err)
 				goto free_npinfo;
 		}
@@ -857,7 +857,7 @@ int netpoll_setup(struct netpoll *np)
 	refill_skbs();
 
 	rtnl_lock();
-	err = __netpoll_setup(np, ndev);
+	err = __netpoll_setup(np, ndev, GFP_KERNEL);
 	rtnl_unlock();
 
 	if (err)
-- 
1.7.7.6

[PATCH 02/14] netpoll: make __netpoll_cleanup non-block

[Cong Wang]

Like the previous patch, slave_disable_netpoll() and __netpoll_cleanup()
may be called with read_lock() held too, so we should make them
non-block, by moving the cleanup and kfree() to call_rcu_bh() callbacks.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 drivers/net/bonding/bond_main.c |    4 +--
 include/linux/netpoll.h         |    3 ++
 net/8021q/vlan_dev.c            |    6 +----
 net/bridge/br_device.c          |    6 +----
 net/core/netpoll.c              |   42 +++++++++++++++++++++++++++++---------
 5 files changed, 38 insertions(+), 23 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 8697136..e428916 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1257,9 +1257,7 @@ static inline void slave_disable_netpoll(struct slave *slave)
 		return;
 
 	slave->np = NULL;
-	synchronize_rcu_bh();
-	__netpoll_cleanup(np);
-	kfree(np);
+	__netpoll_free_rcu(np);
 }
 static inline bool slave_dev_support_netpoll(struct net_device *slave_dev)
 {
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index bf2d51e..907812e 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -23,6 +23,7 @@ struct netpoll {
 	u8 remote_mac[ETH_ALEN];
 
 	struct list_head rx; /* rx_np list element */
+	struct rcu_head rcu;
 };
 
 struct netpoll_info {
@@ -38,6 +39,7 @@ struct netpoll_info {
 	struct delayed_work tx_work;
 
 	struct netpoll *netpoll;
+	struct rcu_head rcu;
 };
 
 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
@@ -48,6 +50,7 @@ int netpoll_setup(struct netpoll *np);
 int netpoll_trap(void);
 void netpoll_set_trap(int trap);
 void __netpoll_cleanup(struct netpoll *np);
+void __netpoll_free_rcu(struct netpoll *np);
 void netpoll_cleanup(struct netpoll *np);
 int __netpoll_rx(struct sk_buff *skb);
 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index ee4ae09..b65623f 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -704,11 +704,7 @@ static void vlan_dev_netpoll_cleanup(struct net_device *dev)
 
 	info->netpoll = NULL;
 
-        /* Wait for transmitting packets to finish before freeing. */
-        synchronize_rcu_bh();
-
-        __netpoll_cleanup(netpoll);
-        kfree(netpoll);
+	__netpoll_free_rcu(netpoll);
 }
 #endif /* CONFIG_NET_POLL_CONTROLLER */
 
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index ed0e0f9..f41ba40 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -267,11 +267,7 @@ void br_netpoll_disable(struct net_bridge_port *p)
 
 	p->np = NULL;
 
-	/* Wait for transmitting packets to finish before freeing. */
-	synchronize_rcu_bh();
-
-	__netpoll_cleanup(np);
-	kfree(np);
+	__netpoll_free_rcu(np);
 }
 
 #endif
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 37cc854..dc17f1d 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -878,6 +878,24 @@ static int __init netpoll_init(void)
 }
 core_initcall(netpoll_init);
 
+static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
+{
+	struct netpoll_info *npinfo =
+			container_of(rcu_head, struct netpoll_info, rcu);
+
+	skb_queue_purge(&npinfo->arp_tx);
+	skb_queue_purge(&npinfo->txq);
+
+	/* we can't call cancel_delayed_work_sync here, as we are in softirq */
+	cancel_delayed_work(&npinfo->tx_work);
+
+	/* clean after last, unfinished work */
+	__skb_queue_purge(&npinfo->txq);
+	/* now cancel it again */
+	cancel_delayed_work(&npinfo->tx_work);
+	kfree(npinfo);
+}
+
 void __netpoll_cleanup(struct netpoll *np)
 {
 	struct netpoll_info *npinfo;
@@ -903,20 +921,24 @@ void __netpoll_cleanup(struct netpoll *np)
 			ops->ndo_netpoll_cleanup(np->dev);
 
 		RCU_INIT_POINTER(np->dev->npinfo, NULL);
+		call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info);
+	}
+}
+EXPORT_SYMBOL_GPL(__netpoll_cleanup);
 
-		/* avoid racing with NAPI reading npinfo */
-		synchronize_rcu_bh();
+static void rcu_cleanup_netpoll(struct rcu_head *rcu_head)
+{
+	struct netpoll *np = container_of(rcu_head, struct netpoll, rcu);
 
-		skb_queue_purge(&npinfo->arp_tx);
-		skb_queue_purge(&npinfo->txq);
-		cancel_delayed_work_sync(&npinfo->tx_work);
+	__netpoll_cleanup(np);
+	kfree(np);
+}
 
-		/* clean after last, unfinished work */
-		__skb_queue_purge(&npinfo->txq);
-		kfree(npinfo);
-	}
+void __netpoll_free_rcu(struct netpoll *np)
+{
+	call_rcu_bh(&np->rcu, rcu_cleanup_netpoll);
 }
-EXPORT_SYMBOL_GPL(__netpoll_cleanup);
+EXPORT_SYMBOL_GPL(__netpoll_free_rcu);
 
 void netpoll_cleanup(struct netpoll *np)
 {
-- 
1.7.7.6

[PATCH 03/14] netconsole: do not release spin_lock when calling __netpoll_cleanup

[Cong Wang]

With the previous patch applied, __netpoll_cleanup() is non-block now,
so we don't need to release the spin_lock before calling it.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 drivers/net/netconsole.c |    5 -----
 1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index f9347ea..f0ad56c 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -640,12 +640,7 @@ static int netconsole_netdev_event(struct notifier_block *this,
 				 * rtnl_lock already held
 				 */
 				if (nt->np.dev) {
-					spin_unlock_irqrestore(
-							      &target_list_lock,
-							      flags);
 					__netpoll_cleanup(&nt->np);
-					spin_lock_irqsave(&target_list_lock,
-							  flags);
 					dev_put(nt->np.dev);
 					nt->np.dev = NULL;
 					netconsole_target_put(nt);
-- 
1.7.7.6

[PATCH 04/14] netpoll: take rcu_read_lock_bh() in netpoll_rx()

[Cong Wang]

In __netpoll_rx(), it dereferences ->npinfo without rcu_dereference_bh(),
this patch fixes it by using the 'npinfo' passed from netpoll_rx()
where it is already dereferenced with rcu_dereference_bh().

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 include/linux/netpoll.h |    4 ++--
 net/core/netpoll.c      |    3 +--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 907812e..5d881c3 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -52,7 +52,7 @@ void netpoll_set_trap(int trap);
 void __netpoll_cleanup(struct netpoll *np);
 void __netpoll_free_rcu(struct netpoll *np);
 void netpoll_cleanup(struct netpoll *np);
-int __netpoll_rx(struct sk_buff *skb);
+int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 			     struct net_device *dev);
 static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
@@ -77,7 +77,7 @@ static inline bool netpoll_rx(struct sk_buff *skb)
 
 	spin_lock(&npinfo->rx_lock);
 	/* check rx_flags again with the lock held */
-	if (npinfo->rx_flags && __netpoll_rx(skb))
+	if (npinfo->rx_flags && __netpoll_rx(skb, npinfo))
 		ret = true;
 	spin_unlock(&npinfo->rx_lock);
 
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index dc17f1d..d055bb0 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -543,13 +543,12 @@ static void arp_reply(struct sk_buff *skb)
 	spin_unlock_irqrestore(&npinfo->rx_lock, flags);
 }
 
-int __netpoll_rx(struct sk_buff *skb)
+int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 {
 	int proto, len, ulen;
 	int hits = 0;
 	const struct iphdr *iph;
 	struct udphdr *uh;
-	struct netpoll_info *npinfo = skb->dev->npinfo;
 	struct netpoll *np, *tmp;
 
 	if (list_empty(&npinfo->rx_np))
-- 
1.7.7.6

[PATCH 05/14] netpoll: use netpoll_rx_on() in netpoll_rx()

[Cong Wang]

The logic of the code is same, just call netpoll_rx_on().

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 include/linux/netpoll.h |   18 +++++++++---------
 1 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 5d881c3..2d178ba 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -63,6 +63,13 @@ static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 
 
 #ifdef CONFIG_NETPOLL
+static inline int netpoll_rx_on(struct sk_buff *skb)
+{
+	struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
+
+	return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
+}
+
 static inline bool netpoll_rx(struct sk_buff *skb)
 {
 	struct netpoll_info *npinfo;
@@ -70,11 +77,11 @@ static inline bool netpoll_rx(struct sk_buff *skb)
 	bool ret = false;
 
 	local_irq_save(flags);
-	npinfo = rcu_dereference_bh(skb->dev->npinfo);
 
-	if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags))
+	if (!netpoll_rx_on(skb))
 		goto out;
 
+	npinfo = rcu_dereference_bh(skb->dev->npinfo);
 	spin_lock(&npinfo->rx_lock);
 	/* check rx_flags again with the lock held */
 	if (npinfo->rx_flags && __netpoll_rx(skb, npinfo))
@@ -86,13 +93,6 @@ out:
 	return ret;
 }
 
-static inline int netpoll_rx_on(struct sk_buff *skb)
-{
-	struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
-
-	return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
-}
-
 static inline int netpoll_receive_skb(struct sk_buff *skb)
 {
 	if (!list_empty(&skb->dev->napi_list))
-- 
1.7.7.6

[PATCH 06/14] netpoll: take rcu_read_lock_bh() in netpoll_send_skb_on_dev()

[Cong Wang]

This patch fixes several problems in the call path of
netpoll_send_skb_on_dev():

1. Disable IRQ's before calling netpoll_send_skb_on_dev().

2. All the callees of netpoll_send_skb_on_dev() should use
   rcu_dereference_bh() to dereference ->npinfo.

3. Rename arp_reply() to netpoll_arp_reply(), the former is too generic.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 include/linux/netpoll.h |    3 +++
 net/core/netpoll.c      |   31 +++++++++++++++++--------------
 2 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 2d178ba..61aee86 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -57,7 +57,10 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 			     struct net_device *dev);
 static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 {
+	unsigned long flags;
+	local_irq_save(flags);
 	netpoll_send_skb_on_dev(np, skb, np->dev);
+	local_irq_restore(flags);
 }
 
 
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index d055bb0..174346a 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -54,7 +54,7 @@ static atomic_t trapped;
 	 MAX_UDP_CHUNK)
 
 static void zap_completion_queue(void);
-static void arp_reply(struct sk_buff *skb);
+static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
 
 static unsigned int carrier_timeout = 4;
 module_param(carrier_timeout, uint, 0644);
@@ -170,7 +170,8 @@ static void poll_napi(struct net_device *dev)
 	list_for_each_entry(napi, &dev->napi_list, dev_list) {
 		if (napi->poll_owner != smp_processor_id() &&
 		    spin_trylock(&napi->poll_lock)) {
-			budget = poll_one_napi(dev->npinfo, napi, budget);
+			budget = poll_one_napi(rcu_dereference_bh(dev->npinfo),
+					       napi, budget);
 			spin_unlock(&napi->poll_lock);
 
 			if (!budget)
@@ -185,13 +186,14 @@ static void service_arp_queue(struct netpoll_info *npi)
 		struct sk_buff *skb;
 
 		while ((skb = skb_dequeue(&npi->arp_tx)))
-			arp_reply(skb);
+			netpoll_arp_reply(skb, npi);
 	}
 }
 
 static void netpoll_poll_dev(struct net_device *dev)
 {
 	const struct net_device_ops *ops;
+	struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
 
 	if (!dev || !netif_running(dev))
 		return;
@@ -206,17 +208,18 @@ static void netpoll_poll_dev(struct net_device *dev)
 	poll_napi(dev);
 
 	if (dev->flags & IFF_SLAVE) {
-		if (dev->npinfo) {
+		if (ni) {
 			struct net_device *bond_dev = dev->master;
 			struct sk_buff *skb;
-			while ((skb = skb_dequeue(&dev->npinfo->arp_tx))) {
+			struct netpoll_info *bond_ni = rcu_dereference_bh(bond_dev->npinfo);
+			while ((skb = skb_dequeue(&ni->arp_tx))) {
 				skb->dev = bond_dev;
-				skb_queue_tail(&bond_dev->npinfo->arp_tx, skb);
+				skb_queue_tail(&bond_ni->arp_tx, skb);
 			}
 		}
 	}
 
-	service_arp_queue(dev->npinfo);
+	service_arp_queue(ni);
 
 	zap_completion_queue();
 }
@@ -302,6 +305,7 @@ static int netpoll_owner_active(struct net_device *dev)
 	return 0;
 }
 
+/* call with IRQ disabled */
 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 			     struct net_device *dev)
 {
@@ -309,8 +313,11 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 	unsigned long tries;
 	const struct net_device_ops *ops = dev->netdev_ops;
 	/* It is up to the caller to keep npinfo alive. */
-	struct netpoll_info *npinfo = np->dev->npinfo;
+	struct netpoll_info *npinfo;
+
+	WARN_ON_ONCE(!irqs_disabled());
 
+	npinfo = rcu_dereference_bh(np->dev->npinfo);
 	if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
 		__kfree_skb(skb);
 		return;
@@ -319,11 +326,9 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 	/* don't get messages out of order, and no recursion */
 	if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
 		struct netdev_queue *txq;
-		unsigned long flags;
 
 		txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
 
-		local_irq_save(flags);
 		/* try until next clock tick */
 		for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
 		     tries > 0; --tries) {
@@ -347,10 +352,9 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 		}
 
 		WARN_ONCE(!irqs_disabled(),
-			"netpoll_send_skb(): %s enabled interrupts in poll (%pF)\n",
+			"netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pF)\n",
 			dev->name, ops->ndo_start_xmit);
 
-		local_irq_restore(flags);
 	}
 
 	if (status != NETDEV_TX_OK) {
@@ -423,9 +427,8 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 }
 EXPORT_SYMBOL(netpoll_send_udp);
 
-static void arp_reply(struct sk_buff *skb)
+static void netpoll_arp_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
 {
-	struct netpoll_info *npinfo = skb->dev->npinfo;
 	struct arphdr *arp;
 	unsigned char *arp_ptr;
 	int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
-- 
1.7.7.6

[PATCH 07/14] bridge: add some comments for NETDEV_RELEASE

[Cong Wang]

Add comments on why we don't notify NETDEV_RELEASE.

Cc: David Miller <davem@davemloft.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 net/bridge/br_if.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 171fd6b..1c8fdc3 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -427,6 +427,10 @@ int br_del_if(struct net_bridge *br, struct net_device *dev)
 	if (!p || p->br != br)
 		return -EINVAL;
 
+	/* Since more than one interface can be attached to a bridge,
+	 * there still maybe an alternate path for netconsole to use;
+	 * therefore there is no reason for a NETDEV_RELEASE event.
+	 */
 	del_nbp(p);
 
 	spin_lock_bh(&br->lock);
-- 
1.7.7.6

[PATCH 08/14] bridge: use list_for_each_entry() in netpoll functions

[Cong Wang]

We don't delete 'p' from the list in the loop,
so we can just use list_for_each_entry().

Cc: David Miller <davem@davemloft.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 net/bridge/br_device.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index f41ba40..32211fa 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -206,21 +206,20 @@ static void br_poll_controller(struct net_device *br_dev)
 static void br_netpoll_cleanup(struct net_device *dev)
 {
 	struct net_bridge *br = netdev_priv(dev);
-	struct net_bridge_port *p, *n;
+	struct net_bridge_port *p;
 
-	list_for_each_entry_safe(p, n, &br->port_list, list) {
+	list_for_each_entry(p, &br->port_list, list)
 		br_netpoll_disable(p);
-	}
 }
 
 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
 			    gfp_t gfp)
 {
 	struct net_bridge *br = netdev_priv(dev);
-	struct net_bridge_port *p, *n;
+	struct net_bridge_port *p;
 	int err = 0;
 
-	list_for_each_entry_safe(p, n, &br->port_list, list) {
+	list_for_each_entry(p, &br->port_list, list) {
 		if (!p->dev)
 			continue;
 		err = br_netpoll_enable(p, gfp);
-- 
1.7.7.6

[PATCH 09/14] netpoll: check netpoll tx status on the right device

[Cong Wang]

Although this doesn't matter actually, because netpoll_tx_running()
doesn't use the parameter, the code will be more readable.

For team_dev_queue_xmit() we have to move it down to avoid
compile errors.

Cc: Jiri Pirko <jpirko@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 drivers/net/bonding/bond_main.c |    2 +-
 include/linux/if_team.h         |   30 +++++++++++++++---------------
 net/bridge/br_forward.c         |    2 +-
 3 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index e428916..d688a8a 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -398,7 +398,7 @@ int bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb,
 		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
 	skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;
 
-	if (unlikely(netpoll_tx_running(slave_dev)))
+	if (unlikely(netpoll_tx_running(bond->dev)))
 		bond_netpoll_send_skb(bond_get_slave_by_dev(bond, slave_dev), skb);
 	else
 		dev_queue_xmit(skb);
diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index 6960fc1..aa2e167 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -96,21 +96,6 @@ static inline void team_netpoll_send_skb(struct team_port *port,
 }
 #endif
 
-static inline int team_dev_queue_xmit(struct team *team, struct team_port *port,
-				      struct sk_buff *skb)
-{
-	BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
-		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
-	skb_set_queue_mapping(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
-
-	skb->dev = port->dev;
-	if (unlikely(netpoll_tx_running(port->dev))) {
-		team_netpoll_send_skb(port, skb);
-		return 0;
-	}
-	return dev_queue_xmit(skb);
-}
-
 struct team_mode_ops {
 	int (*init)(struct team *team);
 	void (*exit)(struct team *team);
@@ -200,6 +185,21 @@ struct team {
 	long mode_priv[TEAM_MODE_PRIV_LONGS];
 };
 
+static inline int team_dev_queue_xmit(struct team *team, struct team_port *port,
+				      struct sk_buff *skb)
+{
+	BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
+		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
+	skb_set_queue_mapping(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
+
+	skb->dev = port->dev;
+	if (unlikely(netpoll_tx_running(team->dev))) {
+		team_netpoll_send_skb(port, skb);
+		return 0;
+	}
+	return dev_queue_xmit(skb);
+}
+
 static inline struct hlist_head *team_port_index_hash(struct team *team,
 						      int port_index)
 {
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index e9466d4..02015a5 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -65,7 +65,7 @@ static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
 {
 	skb->dev = to->dev;
 
-	if (unlikely(netpoll_tx_running(to->dev))) {
+	if (unlikely(netpoll_tx_running(to->br->dev))) {
 		if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
 			kfree_skb(skb);
 		else {
-- 
1.7.7.6

[PATCH 10/14] netpoll: convert several functions to bool

[Cong Wang]

These functions are just boolean, let them return
bool instead of int.

Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 include/linux/netpoll.h |   14 +++++++-------
 1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 61aee86..66d5379 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -66,7 +66,7 @@ static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 
 
 #ifdef CONFIG_NETPOLL
-static inline int netpoll_rx_on(struct sk_buff *skb)
+static inline bool netpoll_rx_on(struct sk_buff *skb)
 {
 	struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
 
@@ -125,7 +125,7 @@ static inline void netpoll_poll_unlock(void *have)
 	}
 }
 
-static inline int netpoll_tx_running(struct net_device *dev)
+static inline bool netpoll_tx_running(struct net_device *dev)
 {
 	return irqs_disabled();
 }
@@ -133,11 +133,11 @@ static inline int netpoll_tx_running(struct net_device *dev)
 #else
 static inline bool netpoll_rx(struct sk_buff *skb)
 {
-	return 0;
+	return false;
 }
-static inline int netpoll_rx_on(struct sk_buff *skb)
+static inline bool netpoll_rx_on(struct sk_buff *skb)
 {
-	return 0;
+	return false;
 }
 static inline int netpoll_receive_skb(struct sk_buff *skb)
 {
@@ -153,9 +153,9 @@ static inline void netpoll_poll_unlock(void *have)
 static inline void netpoll_netdev_init(struct net_device *dev)
 {
 }
-static inline int netpoll_tx_running(struct net_device *dev)
+static inline bool netpoll_tx_running(struct net_device *dev)
 {
-	return 0;
+	return false;
 }
 #endif
 
-- 
1.7.7.6

[PATCH 11/14] vlan: clean up vlan_dev_hard_start_xmit()

[Cong Wang]

Clean up vlan_dev_hard_start_xmit() function.

Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 net/8021q/vlan_dev.c |   27 ++++++++++++++++++++-------
 1 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index b65623f..dedc56c 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -137,9 +137,21 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
 	return rc;
 }
 
+static inline netdev_tx_t vlan_netpoll_send_skb(struct vlan_dev_priv *info, struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	if (info->netpoll)
+		netpoll_send_skb(info->netpoll, skb);
+#else
+	BUG();
+#endif
+	return NETDEV_TX_OK;
+}
+
 static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
 					    struct net_device *dev)
 {
+	struct vlan_dev_priv *info = vlan_dev_priv(dev);
 	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
 	unsigned int len;
 	int ret;
@@ -150,29 +162,30 @@ static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
 	 * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
 	 */
 	if (veth->h_vlan_proto != htons(ETH_P_8021Q) ||
-	    vlan_dev_priv(dev)->flags & VLAN_FLAG_REORDER_HDR) {
+	    info->flags & VLAN_FLAG_REORDER_HDR) {
 		u16 vlan_tci;
-		vlan_tci = vlan_dev_priv(dev)->vlan_id;
+		vlan_tci = info->vlan_id;
 		vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb);
 		skb = __vlan_hwaccel_put_tag(skb, vlan_tci);
 	}
 
-	skb->dev = vlan_dev_priv(dev)->real_dev;
+	skb->dev = info->real_dev;
 	len = skb->len;
-	if (netpoll_tx_running(dev))
-		return skb->dev->netdev_ops->ndo_start_xmit(skb, skb->dev);
+	if (unlikely(netpoll_tx_running(dev)))
+		return vlan_netpoll_send_skb(info, skb);
+
 	ret = dev_queue_xmit(skb);
 
 	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
 		struct vlan_pcpu_stats *stats;
 
-		stats = this_cpu_ptr(vlan_dev_priv(dev)->vlan_pcpu_stats);
+		stats = this_cpu_ptr(info->vlan_pcpu_stats);
 		u64_stats_update_begin(&stats->syncp);
 		stats->tx_packets++;
 		stats->tx_bytes += len;
 		u64_stats_update_end(&stats->syncp);
 	} else {
-		this_cpu_inc(vlan_dev_priv(dev)->vlan_pcpu_stats->tx_dropped);
+		this_cpu_inc(info->vlan_pcpu_stats->tx_dropped);
 	}
 
 	return ret;
-- 
1.7.7.6

[PATCH 12/14] netpoll: handle vlan tags in netpoll tx and rx path

[Cong Wang]

Without this patch, I can't get netconsole logs remotely over
vlan. The reason is probably we don't handle vlan tags in either
netpoll tx or rx path.

I am not sure if I use these vlan functions correctly, at
least this patch works.

Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 net/core/netpoll.c |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 174346a..e4ba3e7 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -26,6 +26,7 @@
 #include <linux/workqueue.h>
 #include <linux/slab.h>
 #include <linux/export.h>
+#include <linux/if_vlan.h>
 #include <net/tcp.h>
 #include <net/udp.h>
 #include <asm/unaligned.h>
@@ -334,6 +335,14 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 		     tries > 0; --tries) {
 			if (__netif_tx_trylock(txq)) {
 				if (!netif_xmit_stopped(txq)) {
+					if (vlan_tx_tag_present(skb) &&
+					    !(netif_skb_features(skb) & NETIF_F_HW_VLAN_TX)) {
+						skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
+						if (unlikely(!skb))
+							break;
+						skb->vlan_tci = 0;
+					}
+
 					status = ops->ndo_start_xmit(skb, dev);
 					if (status == NETDEV_TX_OK)
 						txq_trans_update(txq);
@@ -567,6 +576,12 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
 		return 1;
 	}
 
+	if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
+		skb = vlan_untag(skb);
+		if (unlikely(!skb))
+			goto out;
+	}
+
 	proto = ntohs(eth_hdr(skb)->h_proto);
 	if (proto != ETH_P_IP)
 		goto out;
-- 
1.7.7.6

[PATCH 13/14] netpoll: re-enable irq in poll_napi()

[Cong Wang]

napi->poll() needs IRQ enabled, so we have to re-enable IRQ before
calling it.

Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 net/core/netpoll.c |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index e4ba3e7..346b1eb 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -168,16 +168,24 @@ static void poll_napi(struct net_device *dev)
 	struct napi_struct *napi;
 	int budget = 16;
 
+	WARN_ON_ONCE(!irqs_disabled());
+
 	list_for_each_entry(napi, &dev->napi_list, dev_list) {
+		local_irq_enable();
 		if (napi->poll_owner != smp_processor_id() &&
 		    spin_trylock(&napi->poll_lock)) {
+			rcu_read_lock_bh();
 			budget = poll_one_napi(rcu_dereference_bh(dev->npinfo),
 					       napi, budget);
+			rcu_read_unlock_bh();
 			spin_unlock(&napi->poll_lock);
 
-			if (!budget)
+			if (!budget) {
+				local_irq_disable();
 				break;
+			}
 		}
+		local_irq_disable();
 	}
 }
 
-- 
1.7.7.6

[PATCH 14/14] netconsole.txt: revision of examples for the receiver of kernel messages

[Cong Wang]

From: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>

There are at least 4 implementations of netcat with the BSD-based
being the only one that has to be used without the -p switch to
specify the listening port.

Jan Engelhardt suggested to add an example for socat(1).

Signed-off-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 Documentation/networking/netconsole.txt |   19 +++++++++++++++++--
 1 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/netconsole.txt b/Documentation/networking/netconsole.txt
index 8d02207..2e9e0ae2 100644
--- a/Documentation/networking/netconsole.txt
+++ b/Documentation/networking/netconsole.txt
@@ -51,8 +51,23 @@ Built-in netconsole starts immediately after the TCP stack is
 initialized and attempts to bring up the supplied dev at the supplied
 address.
 
-The remote host can run either 'netcat -u -l -p <port>',
-'nc -l -u <port>' or syslogd.
+The remote host has several options to receive the kernel messages,
+for example:
+
+1) syslogd
+
+2) netcat
+
+   On distributions using a BSD-based netcat version (e.g. Fedora,
+   openSUSE and Ubuntu) the listening port must be specified without
+   the -p switch:
+
+   'nc -u -l -p <port>' / 'nc -u -l <port>' or
+   'netcat -u -l -p <port>' / 'netcat -u -l <port>'
+
+3) socat
+
+   'socat udp-recv:<port> -'
 
 Dynamic reconfiguration:
 ========================
-- 
1.7.7.6

Re: [PATCH 11/14] vlan: clean up vlan_dev_hard_start_xmit()

[Patrick McHardy]

On Fri, 10 Aug 2012, Cong Wang wrote:

> Clean up vlan_dev_hard_start_xmit() function.
>
> Cc: Benjamin LaHaise <bcrl@kvack.org>
> Cc: Patrick McHardy <kaber@trash.net>
> Cc: David Miller <davem@davemloft.net>
> Signed-off-by: Cong Wang <amwang@redhat.com>
> ---
> net/8021q/vlan_dev.c |   27 ++++++++++++++++++++-------
> 1 files changed, 20 insertions(+), 7 deletions(-)
>
> diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
> index b65623f..dedc56c 100644
> --- a/net/8021q/vlan_dev.c
> +++ b/net/8021q/vlan_dev.c
> @@ -137,9 +137,21 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
> 	return rc;
> }
>
> +static inline netdev_tx_t vlan_netpoll_send_skb(struct vlan_dev_priv *info, struct sk_buff *skb)
> +{
> +#ifdef CONFIG_NET_POLL_CONTROLLER
> +	if (info->netpoll)
> +		netpoll_send_skb(info->netpoll, skb);
> +#else
> +	BUG();
> +#endif
> +	return NETDEV_TX_OK;
> +}
> +
> static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
> 					    struct net_device *dev)
> {
> +	struct vlan_dev_priv *info = vlan_dev_priv(dev);

We're consistently using "vlan" for the private data throughout
the code. Please keep it that way.

Re: [PATCH 09/14] netpoll: check netpoll tx status on the right device

[Jiri Pirko]

Fri, Aug 10, 2012 at 09:10:32AM CEST, amwang@redhat.com wrote:
>Although this doesn't matter actually, because netpoll_tx_running()
>doesn't use the parameter, the code will be more readable.
>
>For team_dev_queue_xmit() we have to move it down to avoid
>compile errors.
>
>Cc: Jiri Pirko <jpirko@redhat.com>
>Cc: David Miller <davem@davemloft.net>
>Signed-off-by: Cong Wang <amwang@redhat.com>
>---
> drivers/net/bonding/bond_main.c |    2 +-
> include/linux/if_team.h         |   30 +++++++++++++++---------------
> net/bridge/br_forward.c         |    2 +-
> 3 files changed, 17 insertions(+), 17 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index e428916..d688a8a 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -398,7 +398,7 @@ int bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb,
> 		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
> 	skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;
> 
>-	if (unlikely(netpoll_tx_running(slave_dev)))
>+	if (unlikely(netpoll_tx_running(bond->dev)))
> 		bond_netpoll_send_skb(bond_get_slave_by_dev(bond, slave_dev), skb);
> 	else
> 		dev_queue_xmit(skb);
>diff --git a/include/linux/if_team.h b/include/linux/if_team.h
>index 6960fc1..aa2e167 100644
>--- a/include/linux/if_team.h
>+++ b/include/linux/if_team.h
>@@ -96,21 +96,6 @@ static inline void team_netpoll_send_skb(struct team_port *port,
> }
> #endif
> 
>-static inline int team_dev_queue_xmit(struct team *team, struct team_port *port,
>-				      struct sk_buff *skb)
>-{
>-	BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
>-		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
>-	skb_set_queue_mapping(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
>-
>-	skb->dev = port->dev;
>-	if (unlikely(netpoll_tx_running(port->dev))) {
>-		team_netpoll_send_skb(port, skb);
>-		return 0;
>-	}
>-	return dev_queue_xmit(skb);
>-}
>-
> struct team_mode_ops {
> 	int (*init)(struct team *team);
> 	void (*exit)(struct team *team);
>@@ -200,6 +185,21 @@ struct team {
> 	long mode_priv[TEAM_MODE_PRIV_LONGS];
> };
> 
>+static inline int team_dev_queue_xmit(struct team *team, struct team_port *port,
>+				      struct sk_buff *skb)
>+{
>+	BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
>+		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
>+	skb_set_queue_mapping(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
>+
>+	skb->dev = port->dev;
>+	if (unlikely(netpoll_tx_running(team->dev))) {
>+		team_netpoll_send_skb(port, skb);
>+		return 0;
>+	}
>+	return dev_queue_xmit(skb);
>+}
>+

Is there any particular reason for moving the whole function?

	
> static inline struct hlist_head *team_port_index_hash(struct team *team,
> 						      int port_index)
> {
>diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
>index e9466d4..02015a5 100644
>--- a/net/bridge/br_forward.c
>+++ b/net/bridge/br_forward.c
>@@ -65,7 +65,7 @@ static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
> {
> 	skb->dev = to->dev;
> 
>-	if (unlikely(netpoll_tx_running(to->dev))) {
>+	if (unlikely(netpoll_tx_running(to->br->dev))) {
> 		if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
> 			kfree_skb(skb);
> 		else {
>-- 
>1.7.7.6
>
>--
>To unsubscribe from this list: send the line "unsubscribe netdev" in
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>More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 11/14] vlan: clean up vlan_dev_hard_start_xmit()

[Cong Wang]

On Fri, 2012-08-10 at 09:14 +0200, Patrick McHardy wrote:
> On Fri, 10 Aug 2012, Cong Wang wrote:
> > static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
> > 					    struct net_device *dev)
> > {
> > +	struct vlan_dev_priv *info = vlan_dev_priv(dev);
> 
> We're consistently using "vlan" for the private data throughout
> the code. Please keep it that way.
> 

Ok, I will update it.

Thanks!

Re: [PATCH 09/14] netpoll: check netpoll tx status on the right device

[Cong Wang]

On Fri, 2012-08-10 at 09:20 +0200, Jiri Pirko wrote:
> > 
> >+static inline int team_dev_queue_xmit(struct team *team, struct team_port *port,
> >+				      struct sk_buff *skb)
> >+{
> >+	BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
> >+		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
> >+	skb_set_queue_mapping(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
> >+
> >+	skb->dev = port->dev;
> >+	if (unlikely(netpoll_tx_running(team->dev))) {
> >+		team_netpoll_send_skb(port, skb);
> >+		return 0;
> >+	}
> >+	return dev_queue_xmit(skb);
> >+}
> >+
> 
> Is there any particular reason for moving the whole function?

In the changelog I mentioned:

"For team_dev_queue_xmit() we have to move it down to avoid
compile errors."

Or you mean this isn't clear? As I changed 'port->dev' to 'team->dev',
so the definition of 'struct team' has to be visual to
team_dev_queue_xmit(), therefore I moved to down after that definition.

Thanks!

Re: [PATCH 09/14] netpoll: check netpoll tx status on the right device

[Jiri Pirko]

Fri, Aug 10, 2012 at 09:52:36AM CEST, amwang@redhat.com wrote:
>On Fri, 2012-08-10 at 09:20 +0200, Jiri Pirko wrote:
>> > 
>> >+static inline int team_dev_queue_xmit(struct team *team, struct team_port *port,
>> >+				      struct sk_buff *skb)
>> >+{
>> >+	BUILD_BUG_ON(sizeof(skb->queue_mapping) !=
>> >+		     sizeof(qdisc_skb_cb(skb)->slave_dev_queue_mapping));
>> >+	skb_set_queue_mapping(skb, qdisc_skb_cb(skb)->slave_dev_queue_mapping);
>> >+
>> >+	skb->dev = port->dev;
>> >+	if (unlikely(netpoll_tx_running(team->dev))) {
>> >+		team_netpoll_send_skb(port, skb);
>> >+		return 0;
>> >+	}
>> >+	return dev_queue_xmit(skb);
>> >+}
>> >+
>> 
>> Is there any particular reason for moving the whole function?
>
>In the changelog I mentioned:
>
>"For team_dev_queue_xmit() we have to move it down to avoid
>compile errors."
>
>Or you mean this isn't clear? As I changed 'port->dev' to 'team->dev',
>so the definition of 'struct team' has to be visual to
>team_dev_queue_xmit(), therefore I moved to down after that definition.

Right. Thanks!

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

[PATCH 08/14] bridge: use list_for_each_entry() in netpoll functions

[Cong Wang]

We don't delete 'p' from the list in the loop,
so we can just use list_for_each_entry().

Cc: David Miller <davem@davemloft.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
---
 net/bridge/br_device.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index f41ba40..32211fa 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -206,21 +206,20 @@ static void br_poll_controller(struct net_device *br_dev)
 static void br_netpoll_cleanup(struct net_device *dev)
 {
 	struct net_bridge *br = netdev_priv(dev);
-	struct net_bridge_port *p, *n;
+	struct net_bridge_port *p;
 
-	list_for_each_entry_safe(p, n, &br->port_list, list) {
+	list_for_each_entry(p, &br->port_list, list)
 		br_netpoll_disable(p);
-	}
 }
 
 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
 			    gfp_t gfp)
 {
 	struct net_bridge *br = netdev_priv(dev);
-	struct net_bridge_port *p, *n;
+	struct net_bridge_port *p;
 	int err = 0;
 
-	list_for_each_entry_safe(p, n, &br->port_list, list) {
+	list_for_each_entry(p, &br->port_list, list) {
 		if (!p->dev)
 			continue;
 		err = br_netpoll_enable(p, gfp);
-- 
1.7.7.6