Patchwork [1/7] netpoll: use GFP_ATOMIC in slave_enable_netpoll() and __netpoll_setup()

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Submitter Eric Dumazet
Date Aug. 3, 2012, 10:10 a.m.
Message ID <1343988623.9299.932.camel@edumazet-glaptop>
Download mbox | patch
Permalink /patch/174960/
State RFC
Delegated to: David Miller
Headers show

Comments

Eric Dumazet - Aug. 3, 2012, 10:10 a.m.
On Fri, 2012-08-03 at 17:34 +0800, Cong Wang wrote:
> On Fri, 2012-08-03 at 11:17 +0200, Eric Dumazet wrote:
> > On Fri, 2012-07-27 at 23:37 +0800, Cong Wang wrote:
> > > slave_enable_netpoll() and __netpoll_setup() may be called
> > > with read_lock() held, so should use GFP_ATOMIC to allocate
> > > memory.
> > > 
> > > Cc: "David S. Miller" <davem@davemloft.net>
> > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > > Signed-off-by: Cong Wang <amwang@redhat.com>
> > > ---
> > >  drivers/net/bonding/bond_main.c |    2 +-
> > >  net/core/netpoll.c              |    2 +-
> > >  2 files changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> > > index 6fae5f3..ab773d4 100644
> > > --- a/drivers/net/bonding/bond_main.c
> > > +++ b/drivers/net/bonding/bond_main.c
> > > @@ -1235,7 +1235,7 @@ 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;
> > > diff --git a/net/core/netpoll.c b/net/core/netpoll.c
> > > index b4c90e4..c78a966 100644
> > > --- a/net/core/netpoll.c
> > > +++ b/net/core/netpoll.c
> > > @@ -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_ATOMIC);
> > >  		if (!npinfo) {
> > >  			err = -ENOMEM;
> > >  			goto out;
> > 
> > Yes this works, but maybe you instead could pass/add a gfp_t flags
> > argument to __netpoll_setup() ?
> > 
> > Management tasks should allow GFP_KERNEL allocations to have less
> > failure risks.
> > 
> > Its sad bonding uses the rwlock here instead of a mutex
> > 
> 
> Yup, that is a good idea. I will update this patch.
> 
> Thanks!
> 

I did this , just take it ;)

 drivers/net/bonding/bond_main.c |    6 +++---
 drivers/net/team/team.c         |   14 +++++++-------
 include/linux/netdevice.h       |    2 +-
 include/linux/netpoll.h         |    2 +-
 net/8021q/vlan_dev.c            |    6 +++---
 net/bridge/br_device.c          |   10 +++++-----
 net/bridge/br_if.c              |    2 +-
 net/bridge/br_private.h         |    4 ++--
 net/core/netpoll.c              |    8 ++++----
 9 files changed, 27 insertions(+), 27 deletions(-)




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Amerigo Wang - Aug. 6, 2012, 9:08 a.m.
On Fri, 2012-08-03 at 12:10 +0200, Eric Dumazet wrote: 
> 
> I did this , just take it ;)

Do we have to pass gfp to ->ndo_netpoll_setup() too? It seems no, so far
I don't think we have to do that.

Thanks.

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Eric Dumazet - Aug. 6, 2012, 9:44 a.m.
On Mon, 2012-08-06 at 17:08 +0800, Cong Wang wrote:
> On Fri, 2012-08-03 at 12:10 +0200, Eric Dumazet wrote: 
> > 
> > I did this , just take it ;)
> 
> Do we have to pass gfp to ->ndo_netpoll_setup() too? It seems no, so far
> I don't think we have to do that.
> 
> Thanks.
> 

It is needed.

->ndo_netpoll_setup() is called from __netpoll_setup()

So it would make no sense to allow GFP_KERNEL allocations in
ndo_netpoll_setup() hgandlers if we called __netpoll_setup() with
GFP_ATOMIC gfp



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Amerigo Wang - Aug. 6, 2012, 12:31 p.m.
On Mon, 2012-08-06 at 11:44 +0200, Eric Dumazet wrote:
> On Mon, 2012-08-06 at 17:08 +0800, Cong Wang wrote:
> > On Fri, 2012-08-03 at 12:10 +0200, Eric Dumazet wrote: 
> > > 
> > > I did this , just take it ;)
> > 
> > Do we have to pass gfp to ->ndo_netpoll_setup() too? It seems no, so far
> > I don't think we have to do that.
> > 
> > Thanks.
> > 
> 
> It is needed.
> 
> ->ndo_netpoll_setup() is called from __netpoll_setup()
> 
> So it would make no sense to allow GFP_KERNEL allocations in
> ndo_netpoll_setup() hgandlers if we called __netpoll_setup() with
> GFP_ATOMIC gfp
> 

I see your point. Thanks!


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Patch

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 6fae5f3..ccff590 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 flags)
 {
 	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..3177d6b 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -795,16 +795,16 @@  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 flags)
 {
 	struct netpoll *np;
 	int err;
 
-	np = kzalloc(sizeof(*np), GFP_KERNEL);
+	np = kzalloc(sizeof(*np), flags);
 	if (!np)
 		return -ENOMEM;
 
-	err = __netpoll_setup(np, port->dev);
+	err = __netpoll_setup(np, port->dev, flags);
 	if (err) {
 		kfree(np);
 		return err;
@@ -833,7 +833,7 @@  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 flags)
 {
 	return 0;
 }
@@ -913,7 +913,7 @@  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 +1443,7 @@  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 flags)
 {
 	struct team *team = netdev_priv(dev);
 	struct team_port *port;
@@ -1451,7 +1451,7 @@  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, flags);
 		if (err) {
 			__team_netpoll_cleanup(team);
 			break;
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a9db4f3..2ad76e3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -953,7 +953,7 @@  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 flags);
 	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..d67d4be3 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 flags);
 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..4ca0b39 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -669,19 +669,19 @@  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 flags)
 {
 	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), flags);
 	err = -ENOMEM;
 	if (!netpoll)
 		goto out;
 
-	err = __netpoll_setup(netpoll, real_dev);
+	err = __netpoll_setup(netpoll, real_dev, flags);
 	if (err) {
 		kfree(netpoll);
 		goto out;
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 3334845..efcd36c 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -213,7 +213,7 @@  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 flags)
 {
 	struct net_bridge *br = netdev_priv(dev);
 	struct net_bridge_port *p, *n;
@@ -223,7 +223,7 @@  static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 		if (!p->dev)
 			continue;
 
-		err = br_netpoll_enable(p);
+		err = br_netpoll_enable(p, flags);
 		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 flags)
 {
 	struct netpoll *np;
 	int err = 0;
 
-	np = kzalloc(sizeof(*p->np), GFP_KERNEL);
+	np = kzalloc(sizeof(*p->np), flags);
 	err = -ENOMEM;
 	if (!np)
 		goto out;
 
-	err = __netpoll_setup(np, p->dev);
+	err = __netpoll_setup(np, p->dev, flags);
 	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..bfdb5ab 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 flags);
 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 flags)
 {
 	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)