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Date:   Tue, 10 Jan 2023 16:03:47 -0800
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Yishai Hadas <yishaih@nvidia.com>, linux-kernel@vger.kernel.org,
        linux-block@vger.kernel.org, linux-mm@kvack.org, jgg@nvidia.com,
        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
Message-Id: <20230110160347.c1d771e4ea21e4b95bfa8477@linux-foundation.org>
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        <f37f8e60-d580-0b7c-0fa5-a26ab49c9781@kernel.dk>
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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?