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Date: Mon, 18 Sep 2023 19:15:32 +0100
From: Matthew Wilcox <willy@infradead.org>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: hch@infradead.org, djwong@kernel.org, dchinner@redhat.com,
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	linux-block@vger.kernel.org, p.raghav@samsung.com,
	da.gomez@samsung.com, dan.helmick@samsung.com
Subject: Re: [RFC v2 00/10] bdev: LBS devices support to coexist with
 buffer-heads
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References: <20230915213254.2724586-1-mcgrof@kernel.org>
 <ZQTR0NorkxJlcNBW@casper.infradead.org>
 <ZQiE5HHTLdJOsVPq@bombadil.infradead.org>
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On Mon, Sep 18, 2023 at 10:12:04AM -0700, Luis Chamberlain wrote:
> On Fri, Sep 15, 2023 at 10:51:12PM +0100, Matthew Wilcox wrote:
> > On Fri, Sep 15, 2023 at 02:32:44PM -0700, Luis Chamberlain wrote:
> > > However, an issue is that disabling CONFIG_BUFFER_HEAD in practice is not viable
> > > for many Linux distributions since it also means disabling support for most
> > > filesystems other than btrfs and XFS. So we either support larger order folios
> > > on buffer-heads, or we draw up a solution to enable co-existence. Since at LSFMM
> > > 2023 it was decided we would not support larger order folios on buffer-heads,
> > 
> > Um, I didn't agree to that.
> 
> Coverage on sunsetting buffer-heads talk by LWN:
> 
> https://lwn.net/Articles/931809/
> 
> "the apparent conclusion from the session: the buffer-head layer will be
> converted to use folios internally while minimizing changes visible to
> the filesystems using it. Only single-page folios will be used within
> this new buffer-head layer. Any other desires, he said, can be addressed
> later after this problem has been solved."

Other people said that.  Not me.  I said it was fine for single
buffer_head per folio.