thr3ads.net - Linux Ethernet Bridging - [Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order [Oct 2015]

If this information is useful, please help other people find it:
Share via:

Nikolay Aleksandrov

2015-Oct-12 11:41 UTC

[Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order

From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>

Ido Schimmel reported a problem with switchdev devices because of the
order change of del_nbp operations, more specifically the move of
nbp_vlan_flush() which deletes all vlans and frees vlgrp after the
rx_handler has been unregistered. So in order to fix this break
vlan_flush in two phases:
1. delete all of vlan_group's vlans
2. destroy rhtable and free vlgrp
We execute phase I (free_rht == false) in the same place as before so the
vlans can be cleared and free the vlgrp after the rx_handler has been
unregistered in phase II (free_rht == true).

Reported-by: Ido Schimmel <idosch at mellanox.com>
Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
---
Ido: I hope this fixes it for your case, a test would be much appreciated.

 net/bridge/br_if.c      | 11 ++++++++---
 net/bridge/br_private.h |  8 ++++----
 net/bridge/br_vlan.c    | 17 ++++++++++-------
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 934cae9fa317..74a03c0a4e5f 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -248,6 +248,8 @@ static void del_nbp(struct net_bridge_port *p)
 
 	list_del_rcu(&p->list);
 
+	/* vlan_flush phase I: remove vlans */
+	nbp_vlan_flush(p, false);
 	br_fdb_delete_by_port(br, p, 0, 1);
 	nbp_update_port_count(br);
 
@@ -256,8 +258,10 @@ static void del_nbp(struct net_bridge_port *p)
 	dev->priv_flags &= ~IFF_BRIDGE_PORT;
 
 	netdev_rx_handler_unregister(dev);
-	/* use the synchronize_rcu done by netdev_rx_handler_unregister */
-	nbp_vlan_flush(p);
+	/* use the synchronize_rcu done by netdev_rx_handler_unregister
+	 * vlan_flush phase II: free rht and vlgrp
+	 */
+	nbp_vlan_flush(p, true);
 
 	br_multicast_del_port(p);
 
@@ -281,7 +285,8 @@ void br_dev_delete(struct net_device *dev, struct list_head
*head)
 
 	br_fdb_delete_by_port(br, NULL, 0, 1);
 
-	br_vlan_flush(br);
+	/* vlan_flush execute both phases (see del_nbp) */
+	br_vlan_flush(br, true);
 	br_multicast_dev_del(br);
 	del_timer_sync(&br->gc_timer);
 
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 7d14ba93bba4..3938a976417f 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -682,7 +682,7 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
 			       struct sk_buff *skb);
 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags);
 int br_vlan_delete(struct net_bridge *br, u16 vid);
-void br_vlan_flush(struct net_bridge *br);
+void br_vlan_flush(struct net_bridge *br, bool free_rht);
 struct net_bridge_vlan *br_vlan_find(struct net_bridge_vlan_group *vg, u16
vid);
 void br_recalculate_fwd_mask(struct net_bridge *br);
 int __br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
@@ -694,7 +694,7 @@ int br_vlan_set_default_pvid(struct net_bridge *br, unsigned
long val);
 int __br_vlan_set_default_pvid(struct net_bridge *br, u16 pvid);
 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags);
 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid);
-void nbp_vlan_flush(struct net_bridge_port *port);
+void nbp_vlan_flush(struct net_bridge_port *port, bool free_rht);
 int nbp_vlan_init(struct net_bridge_port *port);
 int nbp_get_num_vlan_infos(struct net_bridge_port *p, u32 filter_mask);
 
@@ -790,7 +790,7 @@ static inline int br_vlan_delete(struct net_bridge *br, u16
vid)
 	return -EOPNOTSUPP;
 }
 
-static inline void br_vlan_flush(struct net_bridge *br)
+static inline void br_vlan_flush(struct net_bridge *br, bool free_rht)
 {
 }
 
@@ -813,7 +813,7 @@ static inline int nbp_vlan_delete(struct net_bridge_port
*port, u16 vid)
 	return -EOPNOTSUPP;
 }
 
-static inline void nbp_vlan_flush(struct net_bridge_port *port)
+static inline void nbp_vlan_flush(struct net_bridge_port *port, bool free_rht)
 {
 }
 
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index a212979257b1..4fb9b23c9838 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -307,15 +307,18 @@ out:
 	return err;
 }
 
-static void __vlan_flush(struct net_bridge_vlan_group *vlgrp)
+static void __vlan_flush(struct net_bridge_vlan_group *vlgrp, bool free_rht)
 {
 	struct net_bridge_vlan *vlan, *tmp;
 
 	__vlan_delete_pvid(vlgrp, vlgrp->pvid);
 	list_for_each_entry_safe(vlan, tmp, &vlgrp->vlan_list, vlist)
 		__vlan_del(vlan);
-	rhashtable_destroy(&vlgrp->vlan_hash);
-	kfree_rcu(vlgrp, rcu);
+
+	if (free_rht) {
+		rhashtable_destroy(&vlgrp->vlan_hash);
+		kfree_rcu(vlgrp, rcu);
+	}
 }
 
 struct sk_buff *br_handle_vlan(struct net_bridge *br,
@@ -569,11 +572,11 @@ int br_vlan_delete(struct net_bridge *br, u16 vid)
 	return __vlan_del(v);
 }
 
-void br_vlan_flush(struct net_bridge *br)
+void br_vlan_flush(struct net_bridge *br, bool free_rht)
 {
 	ASSERT_RTNL();
 
-	__vlan_flush(br_vlan_group(br));
+	__vlan_flush(br_vlan_group(br), free_rht);
 }
 
 struct net_bridge_vlan *br_vlan_find(struct net_bridge_vlan_group *vg, u16 vid)
@@ -957,7 +960,7 @@ int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
 	return __vlan_del(v);
 }
 
-void nbp_vlan_flush(struct net_bridge_port *port)
+void nbp_vlan_flush(struct net_bridge_port *port, bool free_rht)
 {
 	struct net_bridge_vlan_group *vg;
 	struct net_bridge_vlan *vlan;
@@ -968,5 +971,5 @@ void nbp_vlan_flush(struct net_bridge_port *port)
 	list_for_each_entry(vlan, &vg->vlan_list, vlist)
 		vlan_vid_del(port->dev, port->br->vlan_proto, vlan->vid);
 
-	__vlan_flush(vg);
+	__vlan_flush(vg, free_rht);
 }
-- 
2.4.3

Ido Schimmel

2015-Oct-12 17:39 UTC

head link

[Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order

Mon, Oct 12, 2015 at 02:41:08PM IDT, razor at blackwall.org
wrote:>From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
>Hi,
>Ido Schimmel reported a problem with switchdev devices because of the
>order change of del_nbp operations, more specifically the move of
>nbp_vlan_flush() which deletes all vlans and frees vlgrp after the
>rx_handler has been unregistered. So in order to fix this break
>vlan_flush in two phases:
>1. delete all of vlan_group's vlans
>2. destroy rhtable and free vlgrp
>We execute phase I (free_rht == false) in the same place as before so the
>vlans can be cleared and free the vlgrp after the rx_handler has been
>unregistered in phase II (free_rht == true).I don't fully understand the reason for the two-phase cleanup. Please
see below.>
>Reported-by: Ido Schimmel <idosch at mellanox.com>
>Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
>---
>Ido: I hope this fixes it for your case, a test would be much appreciated.This indeed fixes our switchdev issue. Thanks for the
fix!>
> net/bridge/br_if.c      | 11 ++++++++---
> net/bridge/br_private.h |  8 ++++----
> net/bridge/br_vlan.c    | 17 ++++++++++-------
> 3 files changed, 22 insertions(+), 14 deletions(-)
>
>diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
>index 934cae9fa317..74a03c0a4e5f 100644
>--- a/net/bridge/br_if.c
>+++ b/net/bridge/br_if.c
>@@ -248,6 +248,8 @@ static void del_nbp(struct net_bridge_port *p)
> 
> 	list_del_rcu(&p->list);
> 
>+	/* vlan_flush phase I: remove vlans */
>+	nbp_vlan_flush(p, false);
> 	br_fdb_delete_by_port(br, p, 0, 1);
> 	nbp_update_port_count(br);
> 
>@@ -256,8 +258,10 @@ static void del_nbp(struct net_bridge_port *p)
> 	dev->priv_flags &= ~IFF_BRIDGE_PORT;
> 
> 	netdev_rx_handler_unregister(dev);
>-	/* use the synchronize_rcu done by netdev_rx_handler_unregister */
>-	nbp_vlan_flush(p);
>+	/* use the synchronize_rcu done by netdev_rx_handler_unregister
>+	 * vlan_flush phase II: free rht and vlgrp
>+	 */
>+	nbp_vlan_flush(p, true);
> 
> 	br_multicast_del_port(p);
> 
>@@ -281,7 +285,8 @@ void br_dev_delete(struct net_device *dev, struct
list_head *head)
> 
> 	br_fdb_delete_by_port(br, NULL, 0, 1);
> 
>-	br_vlan_flush(br);
>+	/* vlan_flush execute both phases (see del_nbp) */
>+	br_vlan_flush(br, true);
> 	br_multicast_dev_del(br);
> 	del_timer_sync(&br->gc_timer);
> 
>diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
>index 7d14ba93bba4..3938a976417f 100644
>--- a/net/bridge/br_private.h
>+++ b/net/bridge/br_private.h
>@@ -682,7 +682,7 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
> 			       struct sk_buff *skb);
> int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags);
> int br_vlan_delete(struct net_bridge *br, u16 vid);
>-void br_vlan_flush(struct net_bridge *br);
>+void br_vlan_flush(struct net_bridge *br, bool free_rht);
> struct net_bridge_vlan *br_vlan_find(struct net_bridge_vlan_group *vg, u16
vid);
> void br_recalculate_fwd_mask(struct net_bridge *br);
> int __br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
>@@ -694,7 +694,7 @@ int br_vlan_set_default_pvid(struct net_bridge *br,
unsigned long val);
> int __br_vlan_set_default_pvid(struct net_bridge *br, u16 pvid);
> int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags);
> int nbp_vlan_delete(struct net_bridge_port *port, u16 vid);
>-void nbp_vlan_flush(struct net_bridge_port *port);
>+void nbp_vlan_flush(struct net_bridge_port *port, bool free_rht);
> int nbp_vlan_init(struct net_bridge_port *port);
> int nbp_get_num_vlan_infos(struct net_bridge_port *p, u32 filter_mask);
> 
>@@ -790,7 +790,7 @@ static inline int br_vlan_delete(struct net_bridge *br,
u16 vid)
> 	return -EOPNOTSUPP;
> }
> 
>-static inline void br_vlan_flush(struct net_bridge *br)
>+static inline void br_vlan_flush(struct net_bridge *br, bool free_rht)
> {
> }
> 
>@@ -813,7 +813,7 @@ static inline int nbp_vlan_delete(struct net_bridge_port
*port, u16 vid)
> 	return -EOPNOTSUPP;
> }
> 
>-static inline void nbp_vlan_flush(struct net_bridge_port *port)
>+static inline void nbp_vlan_flush(struct net_bridge_port *port, bool
free_rht)
> {
> }
> 
>diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
>index a212979257b1..4fb9b23c9838 100644
>--- a/net/bridge/br_vlan.c
>+++ b/net/bridge/br_vlan.c
>@@ -307,15 +307,18 @@ out:
> 	return err;
> }
> 
>-static void __vlan_flush(struct net_bridge_vlan_group *vlgrp)
>+static void __vlan_flush(struct net_bridge_vlan_group *vlgrp, bool
free_rht)
> {
> 	struct net_bridge_vlan *vlan, *tmp;
> 
> 	__vlan_delete_pvid(vlgrp, vlgrp->pvid);
> 	list_for_each_entry_safe(vlan, tmp, &vlgrp->vlan_list, vlist)
> 		__vlan_del(vlan);
>-	rhashtable_destroy(&vlgrp->vlan_hash);
>-	kfree_rcu(vlgrp, rcu);
>+Why not just issue a synchronize_rcu here and remove the if statement? I
believe that would also be better for when we remove the bridge device
itself. It's fully symmetric with init that way.>+	if (free_rht) {
>+		rhashtable_destroy(&vlgrp->vlan_hash);
>+		kfree_rcu(vlgrp, rcu);
>+	}
> }
> 
> struct sk_buff *br_handle_vlan(struct net_bridge *br,
>@@ -569,11 +572,11 @@ int br_vlan_delete(struct net_bridge *br, u16 vid)
> 	return __vlan_del(v);
> }
> 
>-void br_vlan_flush(struct net_bridge *br)
>+void br_vlan_flush(struct net_bridge *br, bool free_rht)
> {
> 	ASSERT_RTNL();
> 
>-	__vlan_flush(br_vlan_group(br));
>+	__vlan_flush(br_vlan_group(br), free_rht);
> }
> 
> struct net_bridge_vlan *br_vlan_find(struct net_bridge_vlan_group *vg, u16
vid)
>@@ -957,7 +960,7 @@ int nbp_vlan_delete(struct net_bridge_port *port, u16
vid)
> 	return __vlan_del(v);
> }
> 
>-void nbp_vlan_flush(struct net_bridge_port *port)
>+void nbp_vlan_flush(struct net_bridge_port *port, bool free_rht)
> {
> 	struct net_bridge_vlan_group *vg;
> 	struct net_bridge_vlan *vlan;
>@@ -968,5 +971,5 @@ void nbp_vlan_flush(struct net_bridge_port *port)
> 	list_for_each_entry(vlan, &vg->vlan_list, vlist)
> 		vlan_vid_del(port->dev, port->br->vlan_proto, vlan->vid);
> 
>-	__vlan_flush(vg);
>+	__vlan_flush(vg, free_rht);
> }
>-- 
>2.4.3
>

Nikolay Aleksandrov

2015-Oct-12 17:55 UTC

head link

[Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order

On 10/12/2015 07:39 PM, Ido Schimmel wrote:> Mon, Oct 12, 2015 at 02:41:08PM IDT, razor at blackwall.org wrote:
>> From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
>>
> Hi,
> 
>> Ido Schimmel reported a problem with switchdev devices because of the
>> order change of del_nbp operations, more specifically the move of
>> nbp_vlan_flush() which deletes all vlans and frees vlgrp after the
>> rx_handler has been unregistered. So in order to fix this break
>> vlan_flush in two phases:
>> 1. delete all of vlan_group's vlans
>> 2. destroy rhtable and free vlgrp
>> We execute phase I (free_rht == false) in the same place as before so
the
>> vlans can be cleared and free the vlgrp after the rx_handler has been
>> unregistered in phase II (free_rht == true).
> I don't fully understand the reason for the two-phase cleanup. Please
> see below.
>>
>> Reported-by: Ido Schimmel <idosch at mellanox.com>
>> Signed-off-by: Nikolay Aleksandrov <nikolay at
cumulusnetworks.com>
>> ---
>> Ido: I hope this fixes it for your case, a test would be much
appreciated.
> This indeed fixes our switchdev issue. Thanks for the fix!
>>
[snip]>>
>> -static void __vlan_flush(struct net_bridge_vlan_group *vlgrp)
>> +static void __vlan_flush(struct net_bridge_vlan_group *vlgrp, bool
free_rht)
>> {
>> 	struct net_bridge_vlan *vlan, *tmp;
>>
>> 	__vlan_delete_pvid(vlgrp, vlgrp->pvid);
>> 	list_for_each_entry_safe(vlan, tmp, &vlgrp->vlan_list, vlist)
>> 		__vlan_del(vlan);
>> -	rhashtable_destroy(&vlgrp->vlan_hash);
>> -	kfree_rcu(vlgrp, rcu);
>> +
> Why not just issue a synchronize_rcu here and remove the if statement? I
> believe that would also be better for when we remove the bridge device
> itself. It's fully symmetric with init that way.Hi,
I considered that, but I don't want to issue a second synchronize_rcu() for
each
port when deleting them, with this change we avoid a second synchronize_rcu()
and use the rx_handler unregister one. In complex setups with lots of ports
this is a considerable overhead.
For the bridge device del case - the call is the same, there're no two
phases
there.

Cheers,
 Nik

Linux Ethernet Bridging - Oct 2015 - [Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order

[Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order

[Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order

[Bridge] [PATCH net-next 3/4] bridge: vlan: break vlan_flush in two phases to keep old order