Re: Linux 2.6.16-rc3

[Russell King <rmk+lkml@arm.linux.org.uk>]

On Wed, Feb 15, 2006 at 08:56:00PM -0500, James Bottomley wrote:
> On Tue, 2006-02-14 at 10:34 -0600, James Bottomley wrote:
> > Well, I can't solve the problem that it requires memory allocation from
> > IRQ context to operate.  Based on that, it's an unsafe interface.  I'm
> > going to put it inside SCSI for 2.6.16, since it's better than what we
> > have now, but I don't think we can export it globally.
> 
> OK, this is what I'm proposing as the device model fix.  What it does is
> thread context checking APIs throughout the device subsystem.  SCSI can
> then use it simply via device_put_process_context().  Since we have to
> supply the kref_work; I'd plan to do that as an additional element in
> struct scsi_device.
> 
> This, by itself, won't solve the SCSI target problem, but I plan to fix
> that via a device model addition which would have target alloc waiting
> around for any deleted targets to disappear.
> 
> Since this is planned for post 2.6.16, we have plenty of time to argue
> about it.

This is probably an idiotic question, but if there's something in the
scsi release handler can't be called in non-process context, why can't
scsi queue up the release processing via the work API itself, rather
than having to have this additional code and complexity for everyone?

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core