From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Subject: Re: [PATCH 03/10] ext4: Convert mpage_release_unused_pages() to use
 filemap_get_folios()
Date: Wed, 8 Jun 2022 20:55:06 -0700
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To: Matthew Wilcox <willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Cc: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-f2fs-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

On Wed, Jun 08, 2022 at 05:02:40PM +0100, Matthew Wilcox wrote:
> On Wed, Jun 08, 2022 at 01:02:22AM -0700, Christoph Hellwig wrote:
> > On Sun, Jun 05, 2022 at 08:38:47PM +0100, Matthew Wilcox (Oracle) wrote:
> > > If the folio is large, it may overlap the beginning or end of the
> > > unused range.  If it does, we need to avoid invalidating it.
> > 
> > It's never going to be larger for ext4, is it?  But either way,
> > those precautions looks fine.
> 
> I don't want to say "never".  Today, it's not, but if ext4 ever does
> gain support for large folios, then this is a precaution it will need
> to take.  I'm trying not to leave traps when I do conversions.

FYI, this wasn't an objection to the patch, just a hint that the commit
log could spell this out a bit better.