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Date:   Wed, 11 Jan 2023 09:28:29 -0400
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Jens Axboe <axboe@kernel.dk>, Yishai Hadas <yishaih@nvidia.com>,
        linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-mm@kvack.org, logang@deltatee.com, hch@lst.de,
        alex.williamson@redhat.com, leonro@nvidia.com, maorg@nvidia.com
Subject: Re: [PATCH] lib/scatterlist: Fix to calculate the last_pg properly
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References: <20230109144701.83021-1-yishaih@nvidia.com>
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On Tue, Jan 10, 2023 at 04:03:47PM -0800, Andrew Morton wrote:
> On Mon, 9 Jan 2023 20:18:39 -0700 Jens Axboe <axboe@kernel.dk> wrote:
> 
> > On 1/9/23 7:47 AM, Yishai Hadas wrote:
> > > The last_pg is wrong, it is actually the first page of the last
> > > scatterlist element. To get the last page of the last scatterlist
> > > element we have to add prv->length. So it is checking mergability
> > > against the wrong page, Further, a SG element is not guaranteed to end
> > > on a page boundary, so we have to check the sub page location also for
> > > merge eligibility.
> > > 
> > > Fix the above by checking physical contiguity, compute the actual last
> > > page and then call pages_are_mergable().
> > 
> > Reviewed-by: Jens Axboe <axboe@kernel.dk>
> > 
> > Andrew, can you pick this one up?
> 
> This patch is against Yishai's 
> 
> CommitDate: Thu Jan 5 16:01:05 2023 -0400
> 
>     lib/scatterlist: Fix to merge contiguous pages into the last SG properly
>     
> 
> which is in -next, apparently via a tree of Jason's.  So I'll assume
> that Jason will handleit?

It is in v6.2-rc3 already, but sure I will take this too

Jason