[Bridge] Bridge Control using sysfs and Spinlocks

[Bridge] Bridge Control using sysfs and Spinlocks

[Jonathan Chambers`]

I am attempting to change the bridge kernel module so that I have complete 
control over the port states from user space via sysfs.

On code inspection I can see that whenever a reconfiguration of the bridge 
itself is made, i.e. ageing time, forward delay, hello time, etc. then there 
is a spin_lock_bh before the reconfiguration and a spin_unlock_bh after 
reconfiguration.

However, when a reconfiguration of a bridge PORT is made e.g. path cost, 
priority then the spin lock mechanism is not used. Is this correct 
operation? (The old ioctl method uses spin locks on bridge port 
reconfiguration, whereas I am reconfiguring via sysfs)

If I am to change the bridge module to accept requests to change the port 
state should I be using the spin locks?

Thanks in advance

Jon Chambers.

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Re: [Bridge] Bridge Control using sysfs and Spinlocks

[Stephen Hemminger]

On Tue, 18 Oct 2005 13:23:46 +0100
"Jonathan Chambers`" <chamber_j@hotmail.com> wrote:

> I am attempting to change the bridge kernel module so that I have complete 
> control over the port states from user space via sysfs.
> 
> On code inspection I can see that whenever a reconfiguration of the bridge 
> itself is made, i.e. ageing time, forward delay, hello time, etc. then there 
> is a spin_lock_bh before the reconfiguration and a spin_unlock_bh after 
> reconfiguration.

Yes, makes sense to lock those operations. Looks like a simple oversight.

> However, when a reconfiguration of a bridge PORT is made e.g. path cost, 
> priority then the spin lock mechanism is not used. Is this correct 
> operation? (The old ioctl method uses spin locks on bridge port 
> reconfiguration, whereas I am reconfiguring via sysfs)
> 
> If I am to change the bridge module to accept requests to change the port 
> state should I be using the spin locks?
> 
> Thanks in advance
> 
> Jon Chambers.
> 
> _________________________________________________________________
> MSN Messenger 7.5 is now out. Download it for FREE here. 
> http://messenger.msn.co.uk
> 


-- 
Stephen Hemminger <shemminger@osdl.org>
OSDL http://developer.osdl.org/~shemminger