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Date:   Thu, 25 Apr 2019 09:59:33 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Andreas Gruenbacher <agruenba@redhat.com>
Cc:     cluster-devel@redhat.com, Christoph Hellwig <hch@lst.de>,
        Bob Peterson <rpeterso@redhat.com>, Jan Kara <jack@suse.cz>,
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        Edwin =?iso-8859-1?B?VPZy9ms=?= <edvin.torok@citrix.com>,
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Subject: Re: [PATCH 1/2] iomap: Add a page_prepare callback
Message-ID: <20190425075933.GA9374@lst.de>
References: <20190424171804.4305-1-agruenba@redhat.com>
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On Wed, Apr 24, 2019 at 07:18:03PM +0200, Andreas Gruenbacher wrote:
> Add a page_prepare calback that's called before a page is written to.  This
> will be used by gfs2 to start a transaction in page_prepare and end it in
> page_done.  Other filesystems that implement data journaling will require the
> same kind of mechanism.

This looks basically fine to me.  But I think it would be nicer to
add a iomap_page_ops structure so that we don't have to add more
pointers directly to the iomap.  We can make that struct pointer const
also to avoid runtime overwriting attacks.