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Date:   Fri, 7 Feb 2020 17:13:58 +0100
From:   David Sterba <dsterba@suse.cz>
To:     Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
Cc:     Christoph Hellwig <hch@infradead.org>,
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Subject: Re: [PATCH v4 1/5] btrfs: use the page-cache for super block reading
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On Thu, Feb 06, 2020 at 03:29:57PM +0000, Johannes Thumshirn wrote:
> On 06/02/2020 15:58, Christoph Hellwig wrote:
> > Also I just noticed don't even need the kmap/kunmap at all given that the
> > block device mapping is never in highmem.
> > 
> 
> This potentially touches more places, I'll cover that in a dedicated 
> patchset.

Are the kmap/kunmaps anywhere on the buffer_head call paths? I can't
find it anywhere, and given that the mapping does not contain highmem
pages we could rather avoid adding it from the beginning.