xfs: untangle the direct I/O and DAX path, fix DAX locking

[Boaz Harrosh]

On 06/28/2016 04:10 PM, Christoph Hellwig wrote:
> On Sat, Jun 25, 2016 at 09:00:45AM +1000, Dave Chinner wrote:
<>
> 
> Right.  And an existing application can get DAX turned on under its
> back, and will now suddently get different synchronization behavior.
> That is if it's writes happen to be aligned to the fs block size.
> 

Is there an actual application that does that? or is this purely
theoretical right now?


Thanks
Boaz