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Date:   Mon, 9 May 2022 09:30:52 -0400
From:   "Theodore Ts'o" <tytso@mit.edu>
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 18/37] ext4: Convert ext4 to read_folio
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On Sun, May 08, 2022 at 09:31:12PM +0100, Matthew Wilcox (Oracle) wrote:
> This is a "weak" conversion which converts straight back to using pages.
> A full conversion should be performed at some point, hopefully by
> someone familiar with the filesystem.

What worries me about the "weak" conversion is that ext4_read_folio()
(formerly ext4_read_page()) is going to completely the wrong thing if
the folio contains more than a single page.  This seems to
be... scary.  How are callers of aops->read_folio() supposed to know
whether the right thing or the wrong thing will happen if a random
folio is passed to aops->read_folio()?

						- Ted