Re: [RFC] scsi host sysfs support again [0/4]

[Mike Anderson <andmike@us.ibm.com>]

Christoph Hellwig [hch@infradead.org] wrote:
> On Mon, May 05, 2003 at 01:33:15AM -0700, Mike Anderson wrote:
> > Current Known Issues:
> > 	- Current users of scsi_remove_host will need to have there
> > 	  cleanup reordered to support the restoration of the call to the
> > 	  Scsi_Host_Template release.
> 
> That's not going to fly.  Most ->remove calls are surprise removals
> and thus scsi_remove_host must implcy a scsi_set_host_offline and never
> call into the LLDD again.  It can thusly free it's resources nicely
> after it called scsi_remove_host.  struct Scsi_Host itself needs
> refcounting, but as soon as scsi_remove_host is called it must be gone
> as far as the driver is concerned.  Your approch would imply we could
> imply we could get a scsi release callback long after the pci/whatever
> ->remove is called which is a very bad thing.

While scsi_remove_host cannot imply a scsi_set_host_offline unless we
change the previous definition. We indicated that scsi_set_host_offline
may cancel commands in flight which implys some sync point.

Ok I will look at the change you suggest in the morning after I have
some sleep. I guess the first step would be moving the kfree(shost) out
of scsi_unregister. This would then stay around until ref counts go to
zero.

-andmike
--
Michael Anderson
andmike@us.ibm.com