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Date: Mon, 26 Jul 2021 10:19:42 +0200
From: Christoph Hellwig <hch@lst.de>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Dan Williams <dan.j.williams@intel.com>,
	Matthew Wilcox <willy@infradead.org>,
	Andreas Gruenbacher <agruenba@redhat.com>,
	Shiyang Ruan <ruansy.fnst@fujitsu.com>, linux-xfs@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org,
	nvdimm@lists.linux.dev, cluster-devel@redhat.com
Subject: Re: [PATCH 16/27] iomap: switch iomap_bmap to use iomap_iter
Message-ID: <20210726081942.GD14853@lst.de>
References: <20210719103520.495450-1-hch@lst.de> <20210719103520.495450-17-hch@lst.de> <20210719170545.GF22402@magnolia>
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On Mon, Jul 19, 2021 at 10:05:45AM -0700, Darrick J. Wong wrote:
> >  	bno = 0;
> > -	ret = iomap_apply(inode, pos, blocksize, 0, ops, &bno,
> > -			  iomap_bmap_actor);
> > +	while ((ret = iomap_iter(&iter, ops)) > 0) {
> > +		if (iter.iomap.type != IOMAP_MAPPED)
> > +			continue;
> 
> There isn't a mapped extent, so return 0 here, right?

We can't just return 0, we always need the final iomap_iter() call
to clean up in case a ->iomap_end method is supplied.  No for bmap
having and needing one is rather theoretical, but people will copy
and paste that once we start breaking the rules.

From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 26 Jul 2021 10:19:42 +0200
Subject: [Cluster-devel] [PATCH 16/27] iomap: switch iomap_bmap to use
	iomap_iter
In-Reply-To: <20210719170545.GF22402@magnolia>
References: <20210719103520.495450-1-hch@lst.de>
	<20210719103520.495450-17-hch@lst.de>
	<20210719170545.GF22402@magnolia>
Message-ID: <20210726081942.GD14853@lst.de>
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On Mon, Jul 19, 2021 at 10:05:45AM -0700, Darrick J. Wong wrote:
> >  	bno = 0;
> > -	ret = iomap_apply(inode, pos, blocksize, 0, ops, &bno,
> > -			  iomap_bmap_actor);
> > +	while ((ret = iomap_iter(&iter, ops)) > 0) {
> > +		if (iter.iomap.type != IOMAP_MAPPED)
> > +			continue;
> 
> There isn't a mapped extent, so return 0 here, right?

We can't just return 0, we always need the final iomap_iter() call
to clean up in case a ->iomap_end method is supplied.  No for bmap
having and needing one is rather theoretical, but people will copy
and paste that once we start breaking the rules.