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Date: Thu, 14 Dec 2023 19:01:25 +0000
From: Matthew Wilcox <willy@infradead.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Namjae Jeon <linkinjeon@kernel.org>,
	Sungjong Seo <sj1557.seo@samsung.com>, Jan Kara <jack@suse.com>,
	OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
	Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>,
	Dave Kleikamp <shaggy@kernel.org>,
	Bob Copeland <me@bobcopeland.com>, linux-fsdevel@vger.kernel.org,
	linux-ext4@vger.kernel.org, jfs-discussion@lists.sourceforge.net,
	linux-karma-devel@lists.sourceforge.net, linux-mm@kvack.org
Subject: Re: [PATCH 4/9] hfs: remove ->writepage
Message-ID: <ZXtRBarvgSVN5zPx@casper.infradead.org>
References: <20221113162902.883850-1-hch@lst.de>
 <20221113162902.883850-5-hch@lst.de>
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In-Reply-To: <20221113162902.883850-5-hch@lst.de>

On Sun, Nov 13, 2022 at 05:28:57PM +0100, Christoph Hellwig wrote:
> ->writepage is a very inefficient method to write back data, and only
> used through write_cache_pages or a a fallback when no ->migrate_folio
> method is present.
> 
> Set ->migrate_folio to the generic buffer_head based helper, and stop
> wiring up ->writepage for hfs_aops.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Was there a reason you only did this for hfs_aops and not for
hfs_btree_aops?  It feels like anything that just calls
block_write_full_page() in the writepage handler should be converted
to just calling mpage_writepages() in the writepages handler.
I have a few of those conversions done, but obviously they're in
filesystems that are basically untestable.