Re: Calling sd_shutdown when in state SDEV_DEL

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

James Bottomley [James.Bottomley@SteelEye.com] wrote:
> On Wed, 2004-03-24 at 12:04, Mike Anderson wrote:
> > Why setting CANCEL on the device? Future plans for the CANCEL state?
> > You are setting the state to cancel, but not going through
> > scsi_device_cancel as you want IO to still flow.
> 
> Mainly because it was there.  Using CANCEL instead of DEL is appealing
> since it will still allow special I/O.  Would there be an issue with
> refusing new device references in the CANCEL state?

I think this should be ok as this is our (scsi core) own internal
solution to keep ref counts from increasing for the purpose of
eventually allowing everything to cleanup. 

> 
> > While this will solve the problem for removing a single device, this
> > same error will show up when you remove a host unless you remove all
> > devices first through the sysfs interface. Is this ok?
> 
> Sigh, that's a symptom of the host not having a state model ... I need
> to think about adding that.

Well this is my mess. We really have two usages models here but only one
scsi_remove_host interface. One usage calls scsi_remove_host when the
transport is dead and does not want anymore IO to flow through
queuecommand.  The other usage calls during a clean removal (i.e., rmmod
or hotplug) while there are still scsi_device children of the host
adapter as this is easier than deleting the children first.


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