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Subject: Re: regression introduced by "block: Add support for DAX reads/writes
 to block devices"
From: Dan Williams <dan.j.williams@intel.com>
To: "Wilcox, Matthew R" <matthew.r.wilcox@intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>, Linda Knippers <linda.knippers@hp.com>,
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On Thu, Aug 13, 2015 at 12:32 PM, Wilcox, Matthew R
<matthew.r.wilcox@intel.com> wrote:
> I liked the patch you were pushing to request the *page* containing the requested bytes instead of the *block* containing the requested bytes.
>
> For the misaligned partition problem, I was thinking we should change the direct_access API to return a phys_addr_t instead of a pfn.  That way we can return something that isn't actually page aligned, and DAX can take care of making sure it doesn't overshoot the end.


If you go that route please make it __pfn_t + offset rather than
phys_addr_t so we can communicate the PFN_DEV flag among others.