From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Pirko <jiri@resnulli.us>
Subject: Re: [patch net-next RFC 3/3] switchdev: introduce deferred variants
 of obj_add/del helpers
Date: Thu, 8 Oct 2015 10:28:58 +0200
Message-ID: <20151008082858.GC2186@nanopsycho.orion>
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Cc: Linux Netdev List <netdev@vger.kernel.org>,
	David Miller <davem@davemloft.net>, idosch@mellanox.com,
	Elad Raz <eladr@mellanox.com>,
	Scott Feldman <sfeldma@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
	Andrew Lunn <andrew@lunn.ch>,
	john fastabend <john.fastabend@gmail.com>,
	David Laight <David.Laight@aculab.com>
To: Or Gerlitz <gerlitz.or@gmail.com>
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Thu, Oct 08, 2015 at 08:45:58AM CEST, gerlitz.or@gmail.com wrote:
>On Wed, Oct 7, 2015 at 9:30 PM, Jiri Pirko <jiri@resnulli.us> wrote:
>> From: Jiri Pirko <jiri@mellanox.com>
>>
>> Similar to the attr usecase, the caller knows if he is holding RTNL and is
>> in atomic section. So let the called to decide the correct call variant.
>>
>> This allows drivers to sleep inside their ops and wait for hw to get the
>> operation status. Then the status is propagated into switchdev core.
>> This avoids silent errors in drivers.
>>
>> Signed-off-by: Jiri Pirko <jiri@mellanox.com>
>
>> diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
>> index 7f7d551..2086767 100644
>> --- a/net/bridge/br_fdb.c
>> +++ b/net/bridge/br_fdb.c
>> @@ -139,7 +139,7 @@ static void fdb_del_external_learn(struct net_bridge_fdb_entry *f)
>>                 .vid = f->vlan_id,
>>         };
>>
>> -       switchdev_port_obj_del(f->dst->dev, &fdb.obj);
>> +       switchdev_port_obj_del_deferred(f->dst->dev, &fdb.obj);
>>  }
>
>
>>  static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
>> diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
>> index c29f4ee..49e6e6f 100644
>> --- a/net/switchdev/switchdev.c
>> +++ b/net/switchdev/switchdev.c
>> @@ -362,6 +362,75 @@ int switchdev_port_obj_add(struct net_device *dev,
>>  }
>>  EXPORT_SYMBOL_GPL(switchdev_port_obj_add);
>>
>> +struct switchdev_obj_work {
>> +       struct work_struct work;
>> +       struct net_device *dev;
>> +       struct switchdev_obj obj;
>> +       bool add; /* add of del */
>> +};
>> +
>> +static void switchdev_port_obj_work(struct work_struct *work)
>> +{
>> +       struct switchdev_obj_work *ow =
>> +                       container_of(work, struct switchdev_obj_work, work);
>> +       int err;
>> +
>> +       rtnl_lock();
>> +       if (ow->add)
>> +               err = switchdev_port_obj_add(ow->dev, &ow->obj);
>> +       else
>> +               err = switchdev_port_obj_del(ow->dev, &ow->obj);
>> +       if (err && err != -EOPNOTSUPP)
>> +               netdev_err(ow->dev, "failed (err=%d) to %s object (id=%d)\n",
>> +                          err, ow->add ? "add" : "del", ow->obj.id);
>
>This introduced a regression to the 2-phase commit scheme, since the
>prepare commit can fail
>and that would go un-noticed toward the upper layer, agree?

Well, no. This still does the transaction for all lower devices in one
go. No change in that.