2015-05-22 00:56:17

by Linus Lüssing

[permalink] [raw]
Subject: [PATCH net-next] bridge: allow setting hash_max + multicast_router if interface is down

Network managers like netifd (used in OpenWRT for instance) try to
configure interface options after creation but before setting the
interface up.

Unfortunately the sysfs / bridge currently only allows to configure the
hash_max and multicast_router options when the bridge interface is up.
But since br_multicast_init() doesn't start any timers and only sets
default values and initializes timers it should be save to reconfigure
the default values after that, before things actually get active after
the bridge is set up.

With this patch hash_max and multicast_router attributes can be
changed even if the according bridge (port) is down, just like other
other bridge (port) attributes allow too.

Signed-off-by: Linus Lüssing <[email protected]>
---
Changelog:
* [RFC PATCH net-next] -> [PATCH net-next]


net/bridge/br_multicast.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 2d69d5c..066199e 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1775,8 +1775,6 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
int err = -ENOENT;

spin_lock_bh(&br->multicast_lock);
- if (!netif_running(br->dev))
- goto unlock;

switch (val) {
case 0:
@@ -1793,7 +1791,6 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
break;
}

-unlock:
spin_unlock_bh(&br->multicast_lock);

return err;
@@ -1802,18 +1799,15 @@ unlock:
int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
{
struct net_bridge *br = p->br;
- int err = -ENOENT;
+ int err = 0;

spin_lock(&br->multicast_lock);
- if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
- goto unlock;

switch (val) {
case 0:
case 1:
case 2:
p->multicast_router = val;
- err = 0;

if (val < 2 && !hlist_unhashed(&p->rlist))
hlist_del_init_rcu(&p->rlist);
@@ -1834,7 +1828,6 @@ int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
break;
}

-unlock:
spin_unlock(&br->multicast_lock);

return err;
@@ -1939,15 +1932,11 @@ unlock:

int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
{
- int err = -ENOENT;
+ int err = -EINVAL;
u32 old;
struct net_bridge_mdb_htable *mdb;

spin_lock_bh(&br->multicast_lock);
- if (!netif_running(br->dev))
- goto unlock;
-
- err = -EINVAL;
if (!is_power_of_2(val))
goto unlock;

--
1.7.10.4


2015-05-22 01:56:46

by Roopa Prabhu

[permalink] [raw]
Subject: Re: [PATCH net-next] bridge: allow setting hash_max + multicast_router if interface is down

On 5/21/15, 5:56 PM, Linus Lüssing wrote:
> Network managers like netifd (used in OpenWRT for instance) try to
> configure interface options after creation but before setting the
> interface up.
>
> Unfortunately the sysfs / bridge currently only allows to configure the
> hash_max and multicast_router options when the bridge interface is up.
> But since br_multicast_init() doesn't start any timers and only sets
> default values and initializes timers it should be save to reconfigure
> the default values after that, before things actually get active after
> the bridge is set up.
>
> With this patch hash_max and multicast_router attributes can be
> changed even if the according bridge (port) is down, just like other
> other bridge (port) attributes allow too.
>
> Signed-off-by: Linus Lüssing <[email protected]>
> ---
> Changelog:
> * [RFC PATCH net-next] -> [PATCH net-next]
Acked-by: Roopa Prabhu <[email protected]>

we have a similar patch in-house waiting to be up-streamed.

thanks.

2015-05-22 03:11:36

by Cong Wang

[permalink] [raw]
Subject: Re: [PATCH net-next] bridge: allow setting hash_max + multicast_router if interface is down

On Thu, May 21, 2015 at 5:56 PM, Linus Lüssing <[email protected]> wrote:
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index 2d69d5c..066199e 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -1775,8 +1775,6 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
> int err = -ENOENT;
>

Nit: err can be initialized to -EINVAL now.

> spin_lock_bh(&br->multicast_lock);
> - if (!netif_running(br->dev))
> - goto unlock;
>
> switch (val) {
> case 0:
> @@ -1793,7 +1791,6 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
> break;
> }
>
> -unlock:
> spin_unlock_bh(&br->multicast_lock);
>
> return err;
> @@ -1802,18 +1799,15 @@ unlock:
> int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
> {
> struct net_bridge *br = p->br;
> - int err = -ENOENT;
> + int err = 0;
>
> spin_lock(&br->multicast_lock);


Not related with your patch, but why we don't need to disable bh here?

For me it looks like we do use p->rlist in BH context, but I could easily
miss something here.

> - if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
> - goto unlock;
>
> switch (val) {
> case 0:
> case 1:
> case 2:
> p->multicast_router = val;
> - err = 0;
>
> if (val < 2 && !hlist_unhashed(&p->rlist))
> hlist_del_init_rcu(&p->rlist);
> @@ -1834,7 +1828,6 @@ int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
> break;
> }
>
> -unlock:
> spin_unlock(&br->multicast_lock);
>
> return err;


Thanks!

2015-05-22 03:12:12

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH net-next] bridge: allow setting hash_max + multicast_router if interface is down

On Fri, May 22, 2015 at 02:56:01AM +0200, Linus L?ssing wrote:
> Network managers like netifd (used in OpenWRT for instance) try to
> configure interface options after creation but before setting the
> interface up.
>
> Unfortunately the sysfs / bridge currently only allows to configure the
> hash_max and multicast_router options when the bridge interface is up.
> But since br_multicast_init() doesn't start any timers and only sets
> default values and initializes timers it should be save to reconfigure
> the default values after that, before things actually get active after
> the bridge is set up.
>
> With this patch hash_max and multicast_router attributes can be
> changed even if the according bridge (port) is down, just like other
> other bridge (port) attributes allow too.
>
> Signed-off-by: Linus L?ssing <[email protected]>

Acked-by: Herbert Xu <[email protected]>
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

2015-05-22 03:17:48

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH net-next] bridge: allow setting hash_max + multicast_router if interface is down

On Thu, May 21, 2015 at 08:11:32PM -0700, Cong Wang wrote:
>
> For me it looks like we do use p->rlist in BH context, but I could easily
> miss something here.

Because the caller disables BH for us.

Cheers,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

2015-05-22 03:27:48

by Cong Wang

[permalink] [raw]
Subject: Re: [PATCH net-next] bridge: allow setting hash_max + multicast_router if interface is down

On Thu, May 21, 2015 at 8:17 PM, Herbert Xu <[email protected]> wrote:
> On Thu, May 21, 2015 at 08:11:32PM -0700, Cong Wang wrote:
>>
>> For me it looks like we do use p->rlist in BH context, but I could easily
>> miss something here.
>
> Because the caller disables BH for us.
>


Right, I thought port attr setting uses the same way with br attr setting.