[PATCH v2 net-next 1/4] net: add netdev_lockdep_set_classes() helper

[PATCH v2 net-next 1/4] net: add netdev_lockdep_set_classes() helper

[Eric Dumazet]

It is time to add netdev_lockdep_set_classes() helper
so that lockdep annotations per device type are easier to manage.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/bonding/bond_main.c | 24 +-----------------------
 drivers/net/ppp/ppp_generic.c   |  6 +-----
 drivers/net/team/team.c         | 21 +--------------------
 include/linux/netdevice.h       | 17 +++++++++++++++++
 net/bluetooth/6lowpan.c         | 15 +--------------
 net/ieee802154/6lowpan/core.c   | 16 +---------------
 net/l2tp/l2tp_eth.c             |  6 +-----
 7 files changed, 23 insertions(+), 82 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 681af31a60ed..90157e20357e 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4607,28 +4607,6 @@ static int bond_check_params(struct bond_params *params)
 	return 0;
 }
 
-static struct lock_class_key bonding_netdev_xmit_lock_key;
-static struct lock_class_key bonding_netdev_addr_lock_key;
-static struct lock_class_key bonding_tx_busylock_key;
-static struct lock_class_key bonding_qdisc_running_key;
-
-static void bond_set_lockdep_class_one(struct net_device *dev,
-				       struct netdev_queue *txq,
-				       void *_unused)
-{
-	lockdep_set_class(&txq->_xmit_lock,
-			  &bonding_netdev_xmit_lock_key);
-}
-
-static void bond_set_lockdep_class(struct net_device *dev)
-{
-	lockdep_set_class(&dev->addr_list_lock,
-			  &bonding_netdev_addr_lock_key);
-	netdev_for_each_tx_queue(dev, bond_set_lockdep_class_one, NULL);
-	dev->qdisc_tx_busylock = &bonding_tx_busylock_key;
-	dev->qdisc_running_key = &bonding_qdisc_running_key;
-}
-
 /* Called from registration process */
 static int bond_init(struct net_device *bond_dev)
 {
@@ -4641,7 +4619,7 @@ static int bond_init(struct net_device *bond_dev)
 	if (!bond->wq)
 		return -ENOMEM;
 
-	bond_set_lockdep_class(bond_dev);
+	netdev_lockdep_set_classes(bond_dev);
 
 	list_add_tail(&bond->bond_list, &bn->dev_list);
 
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index aeabaa42317f..17953ab15000 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1312,13 +1312,9 @@ ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
 	return stats64;
 }
 
-static struct lock_class_key ppp_tx_busylock;
-static struct lock_class_key ppp_qdisc_running_key;
-
 static int ppp_dev_init(struct net_device *dev)
 {
-	dev->qdisc_tx_busylock = &ppp_tx_busylock;
-	dev->qdisc_running_key = &ppp_qdisc_running_key;
+	netdev_lockdep_set_classes(dev);
 	return 0;
 }
 
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 00eb38956a2c..0a1bb8387d96 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1574,25 +1574,6 @@ static const struct team_option team_options[] = {
 	},
 };
 
-static struct lock_class_key team_netdev_xmit_lock_key;
-static struct lock_class_key team_netdev_addr_lock_key;
-static struct lock_class_key team_tx_busylock_key;
-static struct lock_class_key team_qdisc_running_key;
-
-static void team_set_lockdep_class_one(struct net_device *dev,
-				       struct netdev_queue *txq,
-				       void *unused)
-{
-	lockdep_set_class(&txq->_xmit_lock, &team_netdev_xmit_lock_key);
-}
-
-static void team_set_lockdep_class(struct net_device *dev)
-{
-	lockdep_set_class(&dev->addr_list_lock, &team_netdev_addr_lock_key);
-	netdev_for_each_tx_queue(dev, team_set_lockdep_class_one, NULL);
-	dev->qdisc_tx_busylock = &team_tx_busylock_key;
-	dev->qdisc_running_key = &team_qdisc_running_key;
-}
 
 static int team_init(struct net_device *dev)
 {
@@ -1628,7 +1609,7 @@ static int team_init(struct net_device *dev)
 		goto err_options_register;
 	netif_carrier_off(dev);
 
-	team_set_lockdep_class(dev);
+	netdev_lockdep_set_classes(dev);
 
 	return 0;
 
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 59d7e06d88d5..333fc77a2576 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1945,6 +1945,23 @@ static inline void netdev_for_each_tx_queue(struct net_device *dev,
 		f(dev, &dev->_tx[i], arg);
 }
 
+#define netdev_lockdep_set_classes(dev)				\
+{								\
+	static struct lock_class_key qdisc_tx_busylock_key;	\
+	static struct lock_class_key qdisc_running_key;		\
+	static struct lock_class_key qdisc_xmit_lock_key;	\
+	static struct lock_class_key dev_addr_list_lock_key;	\
+	unsigned int i;						\
+								\
+	dev->qdisc_tx_busylock = &qdisc_tx_busylock_key;	\
+	dev->qdisc_running_key = &qdisc_running_key;		\
+	lockdep_set_class(&dev->addr_list_lock,			\
+			  &dev_addr_list_lock_key); 		\
+	for (i = 0; i < dev->num_tx_queues; i++)		\
+		lockdep_set_class(&dev->_tx[i]._xmit_lock,	\
+				  &qdisc_xmit_lock_key);	\
+}
+
 struct netdev_queue *netdev_pick_tx(struct net_device *dev,
 				    struct sk_buff *skb,
 				    void *accel_priv);
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 977a11e418d0..d020299baba4 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -627,22 +627,9 @@ static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 	return err < 0 ? NET_XMIT_DROP : err;
 }
 
-static struct lock_class_key bt_tx_busylock;
-static struct lock_class_key bt_netdev_xmit_lock_key;
-static struct lock_class_key bt_qdisc_running_key;
-
-static void bt_set_lockdep_class_one(struct net_device *dev,
-				     struct netdev_queue *txq,
-				     void *_unused)
-{
-	lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
-}
-
 static int bt_dev_init(struct net_device *dev)
 {
-	netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
-	dev->qdisc_tx_busylock = &bt_tx_busylock;
-	dev->qdisc_running_key = &bt_qdisc_running_key;
+	netdev_lockdep_set_classes(dev);
 
 	return 0;
 }
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index 14aa5effd29a..4e2b30894224 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -58,23 +58,9 @@ static struct header_ops lowpan_header_ops = {
 	.create	= lowpan_header_create,
 };
 
-static struct lock_class_key lowpan_tx_busylock;
-static struct lock_class_key lowpan_netdev_xmit_lock_key;
-static struct lock_class_key lowpan_qdisc_running_key;
-
-static void lowpan_set_lockdep_class_one(struct net_device *ldev,
-					 struct netdev_queue *txq,
-					 void *_unused)
-{
-	lockdep_set_class(&txq->_xmit_lock,
-			  &lowpan_netdev_xmit_lock_key);
-}
-
 static int lowpan_dev_init(struct net_device *ldev)
 {
-	netdev_for_each_tx_queue(ldev, lowpan_set_lockdep_class_one, NULL);
-	ldev->qdisc_tx_busylock = &lowpan_tx_busylock;
-	ldev->qdisc_running_key = &lowpan_qdisc_running_key;
+	netdev_lockdep_set_classes(ldev);
 
 	return 0;
 }
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index c00d72d182fa..57fc5a46ce06 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -67,9 +67,6 @@ static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
 	return net_generic(net, l2tp_eth_net_id);
 }
 
-static struct lock_class_key l2tp_eth_tx_busylock;
-static struct lock_class_key l2tp_qdisc_running_key;
-
 static int l2tp_eth_dev_init(struct net_device *dev)
 {
 	struct l2tp_eth *priv = netdev_priv(dev);
@@ -77,8 +74,7 @@ static int l2tp_eth_dev_init(struct net_device *dev)
 	priv->dev = dev;
 	eth_hw_addr_random(dev);
 	eth_broadcast_addr(dev->broadcast);
-	dev->qdisc_tx_busylock = &l2tp_eth_tx_busylock;
-	dev->qdisc_running_key = &l2tp_qdisc_running_key;
+	netdev_lockdep_set_classes(dev);
 
 	return 0;
 }
-- 
2.8.0.rc3.226.g39d4020

[PATCH v2 net-next 2/4] net: vrf: call netdev_lockdep_set_classes()

[Eric Dumazet]

In case a qdisc is used on a vrf device, we need to use different
lockdep classes to avoid false positives.

Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a seqcount")
Reported-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/vrf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 1b214ea4619a..ee6bc1c5c1ce 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -657,7 +657,7 @@ static int vrf_dev_init(struct net_device *dev)
 
 	/* similarly, oper state is irrelevant; set to up to avoid confusion */
 	dev->operstate = IF_OPER_UP;
-
+	netdev_lockdep_set_classes(dev);
 	return 0;
 
 out_rth:
-- 
2.8.0.rc3.226.g39d4020

[PATCH v2 net-next 3/4] net: macvlan: call netdev_lockdep_set_classes()

[Eric Dumazet]

In case a qdisc is used on a macvlan device, we need to use different
lockdep classes to avoid false positives.

Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a seqcount")
Fixes: 79640a4ca695 ("net: add additional lock to qdisc to increase throughput")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/macvlan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 0c65bd914aed..b0c6f5b43f67 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -823,6 +823,7 @@ static void macvlan_set_lockdep_class(struct net_device *dev)
 				       &macvlan_netdev_addr_lock_key,
 				       macvlan_get_nest_level(dev));
 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
+	netdev_lockdep_set_classes(dev);
 }
 
 static int macvlan_init(struct net_device *dev)
-- 
2.8.0.rc3.226.g39d4020

[PATCH v2 net-next 4/4] net: ipvlan: call netdev_lockdep_set_classes()

[Eric Dumazet]

In case a qdisc is used on a ipvlan device, we need to use different
lockdep classes to avoid false positives.

Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a seqcount")
Fixes: 79640a4ca695 ("net: add additional lock to qdisc to increase throughput")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/ipvlan/ipvlan_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 1c4d395fbd49..dee2e67db065 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -107,6 +107,7 @@ static void ipvlan_set_lockdep_class(struct net_device *dev)
 {
 	lockdep_set_class(&dev->addr_list_lock, &ipvlan_netdev_addr_lock_key);
 	netdev_for_each_tx_queue(dev, ipvlan_set_lockdep_class_one, NULL);
+	netdev_lockdep_set_classes(dev);
 }
 
 static int ipvlan_init(struct net_device *dev)
-- 
2.8.0.rc3.226.g39d4020

Re: [PATCH v2 net-next 2/4] net: vrf: call netdev_lockdep_set_classes()

[David Ahern]

On 6/8/16 9:29 PM, Eric Dumazet wrote:
> In case a qdisc is used on a vrf device, we need to use different
> lockdep classes to avoid false positives.
>
> Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a seqcount")
> Reported-by: David Ahern <dsa@cumulusnetworks.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

same result with this patch set.

Re: [PATCH v2 net-next 2/4] net: vrf: call netdev_lockdep_set_classes()

[Eric Dumazet]

On Wed, Jun 8, 2016 at 8:41 PM, David Ahern <dsa@cumulusnetworks.com> wrote:
> On 6/8/16 9:29 PM, Eric Dumazet wrote:
>>
>> In case a qdisc is used on a vrf device, we need to use different
>> lockdep classes to avoid false positives.
>>
>> Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a
>> seqcount")
>> Reported-by: David Ahern <dsa@cumulusnetworks.com>
>> Signed-off-by: Eric Dumazet <edumazet@google.com>
>
>
> same result with this patch set.
>

Are you stacking multiple vrf devices ?

Re: [PATCH v2 net-next 2/4] net: vrf: call netdev_lockdep_set_classes()

[David Ahern]

> On Jun 8, 2016, at 10:01 PM, Eric Dumazet <edumazet@google.com> wrote:
> 
>> On Wed, Jun 8, 2016 at 8:41 PM, David Ahern <dsa@cumulusnetworks.com> wrote:
>>> On 6/8/16 9:29 PM, Eric Dumazet wrote:
>>> 
>>> In case a qdisc is used on a vrf device, we need to use different
>>> lockdep classes to avoid false positives.
>>> 
>>> Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a
>>> seqcount")
>>> Reported-by: David Ahern <dsa@cumulusnetworks.com>
>>> Signed-off-by: Eric Dumazet <edumazet@google.com>
>> 
>> 
>> same result with this patch set.
> 
> Are you stacking multiple vrf devices ?

No. You can also look at ipvlan. It shows the same trace. For me it is 3 commands that create the vrf, add eth1, run ping. 

Re: [PATCH v2 net-next 2/4] net: vrf: call netdev_lockdep_set_classes()

[Eric Dumazet]

On Wed, Jun 8, 2016 at 9:35 PM, David Ahern <dsa@cumulusnetworks.com> wrote:
>
>> On Jun 8, 2016, at 10:01 PM, Eric Dumazet <edumazet@google.com> wrote:
>>
>>> On Wed, Jun 8, 2016 at 8:41 PM, David Ahern <dsa@cumulusnetworks.com> wrote:
>>>> On 6/8/16 9:29 PM, Eric Dumazet wrote:
>>>>
>>>> In case a qdisc is used on a vrf device, we need to use different
>>>> lockdep classes to avoid false positives.
>>>>
>>>> Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a
>>>> seqcount")
>>>> Reported-by: David Ahern <dsa@cumulusnetworks.com>
>>>> Signed-off-by: Eric Dumazet <edumazet@google.com>
>>>
>>>
>>> same result with this patch set.
>>
>> Are you stacking multiple vrf devices ?
>
> No. You can also look at ipvlan. It shows the same trace. For me it is 3 commands that create the vrf, add eth1, run ping.


Okay, lockdep is hard ;)

I will send a v3 after some sleep, adding the following :

(I might have to add a new seqcount api instead of hard coding it)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c4f5749342ec..d53ecfc1d60e 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -104,7 +104,11 @@ static inline bool qdisc_run_begin(struct Qdisc *qdisc)
 {
        if (qdisc_is_running(qdisc))
                return false;
-       write_seqcount_begin(&qdisc->running);
+       /* Variant of write_seqcount_begin() telling lockdep a trylock
+        * was attempted.
+        */
+       raw_write_seqcount_begin(&qdisc->running);
+       seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
        return true;
 }

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index cebea73e70ac..cad810b45e31 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -137,10 +137,10 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,

                HARD_TX_UNLOCK(dev, txq);
        } else {
-               spin_lock_nested(root_lock, SINGLE_DEPTH_NESTING);
+               spin_lock(root_lock);
                return qdisc_qlen(q);
        }
-       spin_lock_nested(root_lock, SINGLE_DEPTH_NESTING);
+       spin_lock(root_lock);

        if (dev_xmit_complete(ret)) {
                /* Driver sent out skb successfully or skb was consumed */

Re: [PATCH v2 net-next 2/4] net: vrf: call netdev_lockdep_set_classes()

[David Miller]

From: Eric Dumazet <edumazet@google.com>
Date: Wed, 8 Jun 2016 21:01:35 -0700

> On Wed, Jun 8, 2016 at 8:41 PM, David Ahern <dsa@cumulusnetworks.com> wrote:
>> On 6/8/16 9:29 PM, Eric Dumazet wrote:
>>>
>>> In case a qdisc is used on a vrf device, we need to use different
>>> lockdep classes to avoid false positives.
>>>
>>> Fixes: f9eb8aea2a1e ("net_sched: transform qdisc running bit into a
>>> seqcount")
>>> Reported-by: David Ahern <dsa@cumulusnetworks.com>
>>> Signed-off-by: Eric Dumazet <edumazet@google.com>
>>
>>
>> same result with this patch set.
>>
> 
> Are you stacking multiple vrf devices ?

Ok I'm holding off on this patch series until this is resolved.