[dm-devel] [PATCH 3/3] dm mpath: add support for using previously attached scsi_dh
Mike Snitzer
snitzer at redhat.com
Tue May 8 14:05:41 UTC 2012
On Tue, May 08 2012 at 2:22am -0400,
Hannes Reinecke <hare at suse.de> wrote:
> On 05/08/2012 05:19 AM, Mike Snitzer wrote:
> > Use the previously attached scsi_dh if "default" is provided as the
> > hardware handler name (the new 'use_default_hw_handler' flag is set in
> > the multipath structure).
> >
> > Leverage scsi_dh_attach's ability to increment the scsi_dh's reference
> > count if the same scsi_dh name is provided when attaching -- currently
> > attached scsi_dh name is determined with scsi_dh_attached_handler_name.
> >
> Not sure it that's the correct way.
>
> Using 'default' as the hardware handler name has the drawback that
> the original information (ie the original hardware handler name)
> is lost.
BTW, on this point: How is the original handler's name lost with my
patches? I set m->hw_handler_name to the original (aka attached)
handler's name (as returned scsi_dh_attached_handler_name).
"default" is only used as a key to trigger the use of the attached
handler (it causes m->use_default_hw_handler to be set).
Was my description or code somehow unclear? Guess so... otherwise I'd
not be clarifying this... unfortunately I'm not seeing where I fell
short.
Mike
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