On Thu, Aug 25, 2016 at 12:57:28AM -0700, Christoph Hellwig wrote:

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.

Sure, I'll take a look.