Re: [PATCH 1/3] zpool: add zpool_has_pool()

From: Seth Jennings
Date: Thu Aug 06 2015 - 17:56:16 EST


On Wed, Aug 05, 2015 at 03:06:59PM -0700, Andrew Morton wrote:
> On Wed, 5 Aug 2015 18:00:26 -0400 Dan Streetman <ddstreet@xxxxxxxx> wrote:
>
> > >
> > > If there's some reason why this can't happen, can we please have a code
> > > comment which reveals that reason?
> >
> > zpool_create_pool() should work if this returns true, unless as you
> > say the module is rmmod'ed *and* removed from the system - since
> > zpool_create_pool() will call request_module() just as this function
> > does. I can add a comment explaining that.
>
> I like comments ;)
>
> Seth, I'm planning on sitting on these patches until you've had a
> chance to review them.

Thanks Andrew. I'm reviewing now. Patch 2/3 is pretty huge. I've got
the gist of the changes now. I'm also building and testing for myself
as this creates a lot more surface area for issues, alternating between
compressors and allocating new compression transforms on the fly.

I'm kinda with Sergey on this in that it adds yet another complexity to
an already complex feature. This adds more locking, more RCU, more
refcounting. It's becoming harder to review, test, and verify.

I should have results tomorrow.

Thanks,
Seth
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