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Date: Wed, 29 May 2024 07:20:18 +0200
From: Christoph Hellwig <hch@lst.de>
To: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>, linux-fsdevel@vger.kernel.org,
	linux-ext4@vger.kernel.org
Subject: Re: [PATCH 0/7] Start moving write_begin/write_end out of aops
Message-ID: <20240529052018.GA15312@lst.de>
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On Tue, May 28, 2024 at 05:48:21PM +0100, Matthew Wilcox (Oracle) wrote:
> Christoph wants to remove write_begin/write_end from aops and pass them
> to filemap as callback functions.  Here's one possible route to do this.
> I combined it with the folio conversion (because why touch the same code
> twice?) and tweaked some of the other things (support for ridiculously
> large folios with size_t lengths, remove the need to initialise fsdata
> by passing only a pointer to the fsdata pointer).  And then I converted
> ext4, which is probably the worst filesystem to convert because it needs
> three different bwops.  Most fs will only need one.

Hopefully ext4 will get convert to iomap before we need this.. :)

More seriously, there is an ext4 iomap conversion in progress and a
ext2 one, which is a really good copy & paste model for a lot of the
simple file systems.  Maybe just wait for some of this to settle
to avoid a lot of duplicate work?