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Date:   Mon, 21 Jun 2021 15:32:44 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     David Howells <dhowells@redhat.com>
Cc:     linux-cachefs@redhat.com, linux-afs@lists.infradead.org,
        Jeff Layton <jlayton@kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/3] afs: Handle len being extending over page end in
 write_begin/write_end
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On Thu, Jun 17, 2021 at 09:24:02AM +0100, David Howells wrote:
> With transparent huge pages, in the future, write_begin() and write_end()
> may be passed a length parameter that, in combination with the offset into
> the page, exceeds the length of that page.  This allows
> grab_cache_page_write_begin() to better choose the size of THP to allocate.

While this is all true, it's really not necessary at this point in time.
That change will come with a conversion of these functions to work with
folios and basically every line you change here will change again.