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Date: Thu, 13 Nov 2025 11:06:30 +0100
From: Christoph Hellwig <hch@lst.de>
To: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>, Christian Brauner <brauner@kernel.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	"Darrick J. Wong" <djwong@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Avi Kivity <avi@scylladb.com>, Damien Le Moal <dlemoal@kernel.org>,
	Naohiro Aota <naohiro.aota@wdc.com>,
	Johannes Thumshirn <jth@kernel.org>, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org
Subject: Re: [PATCH 4/5] iomap: support write completions from interrupt
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On Thu, Nov 13, 2025 at 10:54:46AM +0100, Jan Kara wrote:
> > You mean drop the common helper?  How would that be better and less
> > fragile?   Note that I care strongly, but I don't really see the point.
> 
> Sorry I was a bit terse. What I meant is that the two users of
> iomap_dio_is_overwrite() actually care about different things and that
> results in that function having a bit odd semantics IMHO. The first user
> wants to figure out whether calling generic_write_sync() is needed upon io
> completion to make data persistent (crash safe).

Yes.

> The second user cares
> whether we need to do metadata modifications upon io completion to make data
> visible at all.

Not quite.  It cares if either generic_write_sync needs be called,
or we need a metadata modification, because both require the workqueue.