Re: [PATCH 1/3] Always run Grow_continue() for started array.

[NeilBrown <neilb@suse.de>]

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On Wed, 5 Oct 2011 07:04:01 +0000 "Kwolek, Adam" <adam.kwolek@intel.com>
wrote:

> 
> 
> > -----Original Message-----
> > From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
> > owner@vger.kernel.org] On Behalf Of NeilBrown
> > Sent: Wednesday, October 05, 2011 4:59 AM
> > To: Kwolek, Adam
> > Cc: linux-raid@vger.kernel.org; Ciechanowski, Ed; Labun, Marcin; Williams,
> > Dan J
> > Subject: Re: [PATCH 1/3] Always run Grow_continue() for started array.
> > 
> > On Tue, 04 Oct 2011 17:53:49 +0200 Adam Kwolek <adam.kwolek@intel.com>
> > wrote:
> > 
> > > So far there were 2 reshape continuation cases:
> > >  1. array is started /e.g. reshape was already invoked during initrd
> > >                       start-up stage using "--freeze-reshape" option/
> > > 2. array is not started yet /"normal" assembling array under reshape
> > > case/
> > >
> > > This patch narrows continuation cases in to single one. To do this
> > > array should be started /set readonly in to array_state/ before
> > > calling
> > > Grow_continue() function.
> > >
> > > Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
> > 
> > I mostly like this patch.
> > However it seems to have lost something in Grow_continue.
> > The distinction between ->reshape_active==1 and ->reshape_active==2 is
> > lost.
> > 
> > ==1 means just this array is in the middle of a reshape.
> > ==2 means that the whole container is being reshaped and after this array is
> > done we need to move on to the next one.
> > 
> > Was there are reason you removed that?  If not, please put it back.
> 
> In both cases metadata is updated already and container _reshape() goes (somehow) directly to reshape array.
> In container reshape case mdmon moves changes to next array for reshape and container_reshape() will continue with next one.
> 
> In case that single array is reshaped only mdmon finalizes reshape and container_reshape() finds no more arrays under reshape,
> So this would means end of work also.
> 
> In my opinion during reshape continuation we do not need to know if this is container or single array reshape,
> Both cases can be handled by container_reshape() /external metadata/ and we do not need to track what kind of reshape occurs.
> 
> Let me know your opinion.

Yes, that makes sense.

I don't seem to have the original patch any more.  If you could send it again
I'll apply it.

NeilBrown


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