From: Christoph Hellwig <hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
Subject: Re: [PATCH v2 2/9] ext2: tell DAX the size of allocation holes
Date: Thu, 25 Aug 2016 00:57:28 -0700
Message-ID: <20160825075728.GA11235@infradead.org>
References: <20160823220419.11717-1-ross.zwisler@linux.intel.com>
 <20160823220419.11717-3-ross.zwisler@linux.intel.com>
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Cc: Theodore Ts'o <tytso-3s7WtUTddSA@public.gmane.org>, Matthew Wilcox <mawilcox-0li6OtcxBFHby3iVrkZq2A@public.gmane.org>,
 linux-nvdimm-y27Ovi1pjclAfugRpC6u6w@public.gmane.org, Dave Chinner <david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org>,
 linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
 Andreas Dilger <adilger.kernel-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org>,
 Alexander Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>, Jan Kara <jack-IBi9RG/b67k@public.gmane.org>,
 linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
 linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
To: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
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Hi Ross,

can you take at my (fully working, but not fully cleaned up) version
of the iomap based DAX code here:

http://git.infradead.org/users/hch/vfs.git/shortlog/refs/heads/iomap-dax

By using iomap we don't even have the size hole problem and totally
get out of the reverse-engineer what buffer_heads are trying to tell
us business.  It also gets rid of the other warts of the DAX path
due to pretending to be like direct I/O, so this might be a better
way forward also for ext2/4.