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Date: Thu, 13 Nov 2025 06:23:37 +0100
From: Christoph Hellwig <hch@lst.de>
To: Dave Chinner <david@fromorbit.com>
Cc: Ojaswin Mujoo <ojaswin@linux.ibm.com>,
	Christian Brauner <brauner@kernel.org>, djwong@kernel.org,
	ritesh.list@gmail.com, john.g.garry@oracle.com, tytso@mit.edu,
	willy@infradead.org, dchinner@redhat.com, hch@lst.de,
	linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-mm@kvack.org, jack@suse.cz, nilay@linux.ibm.com,
	martin.petersen@oracle.com, rostedt@goodmis.org, axboe@kernel.dk,
	linux-block@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 0/8] xfs: single block atomic writes for buffered IO
Message-ID: <20251113052337.GA28533@lst.de>
References: <cover.1762945505.git.ojaswin@linux.ibm.com> <aRUCqA_UpRftbgce@dread.disaster.area>
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On Thu, Nov 13, 2025 at 08:56:56AM +1100, Dave Chinner wrote:
> On Wed, Nov 12, 2025 at 04:36:03PM +0530, Ojaswin Mujoo wrote:
> > This patch adds support to perform single block RWF_ATOMIC writes for
> > iomap xfs buffered IO. This builds upon the inital RFC shared by John
> > Garry last year [1]. Most of the details are present in the respective 
> > commit messages but I'd mention some of the design points below:
> 
> What is the use case for this functionality? i.e. what is the
> reason for adding all this complexity?

Seconded.  The atomic code has a lot of complexity, and further mixing
it with buffered I/O makes this even worse.  We'd need a really important
use case to even consider it.