Re: How to tell whether a struct file is held by a process?

From: Kay Sievers
Date: Sat May 23 2009 - 18:48:22 EST


On Sat, May 23, 2009 at 00:07, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:

>> Can't we just add ioctls to the hub device
>> nodes to implement the locking?
>
> Yes, that would work. ÂClosing the hub device file would release all
> the locked ports.
>
> It wouldn't leave any lock files for user programs. ÂThey would have to
> arrange the locking among themselves somehow. ÂWould that be okay?

I would expect that userspace drivers competing about raw USB devices
wouldn't be that common. And I guess, most of these problems can
probably be solved by simple file permissions/ACLs applied to the USB
device nodes, in the same way the access to the hub device node would
be granted to lock-out the kernel drivers.

Kay
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