Re: [dm-devel] [RESEND PATCH 2/3] dm mpath: add 'default_hw_handler' feature

[Alasdair G Kergon <agk@redhat.com>]

On Wed, Jun 27, 2012 at 08:16:55AM +0200, Hannes Reinecke wrote:
> On 06/26/2012 08:32 PM, Mike Snitzer wrote:
> > When specifying the feature 'default_hw_handler' multipath will use
> > the currently attached hardware handler instead of trying to attach the
> > one specified during table load.  If no hardware handler is attached the
> > specified hardware handler will be used.
> > 
> > Leverages 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.
> > 
> > Signed-off-by: Mike Snitzer <snitzer@redhat.com>
> > Tested-by: Babu Moger <babu.moger@netapp.com>
> > Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
> Looks good.
 
Maybe, but I'd like to see an inline explanation of what this confusing new
setting means and a better patch header that provides some motivation for this
change.

To my eyes, the word "default" is over-used here.  If I *don't* specify the new
"default" flag, surely I'll get default behaviour, won't I, by definition?  And
if I do specify it, I'm asking for default behaviour too, so isn't it
redundant?

Alasdair