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Date: Thu, 1 Mar 2007 21:00:44 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: support@coraid.com, "Ed L. Cashin" <ecashin@coraid.com>,
       linux-kernel@vger.kernel.org, Greg KH <greg@kroah.com>
Subject: Re: PATCH 2.6.21-rc1 aoe: handle zero _count pages in bios
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On Fri, 2 Mar 2007 04:49:10 +0000 Christoph Hellwig <hch@infradead.org> wrote:

> On Thu, Mar 01, 2007 at 08:48:06PM -0800, Andrew Morton wrote:
> > On Fri, 2 Mar 2007 04:30:39 +0000 Christoph Hellwig <hch@infradead.org> wrote:
> > 
> > > But in this case we'd really need to enforce this, and add a
> > > BUG_ON(PageSlab(page)) in bio_add_page to trip everyone submit
> > > this kind of pages.
> > 
> > That would be
> > 
> > 	BUG_ON(PageSlab(page) && page_count(page) == 0)?
> 
> No, all slab pages.  Currently they all have a reference count of
> zero, but we generally don't want people to pass in pages that
> come from a non-refcounted allocator.

I that case we're talking about different things.

I thought the proposal was to continue to use slab pages, but to take a ref
on them as they're added to the bio, drop that ref in bi_end_io()?