[PATCH 22/29] iomap: add a IOMAP_DAX flag

[Christoph Hellwig]

On Tue, Nov 23, 2021 at 06:47:10PM -0800, Dan Williams wrote:
> On Tue, Nov 9, 2021 at 12:34 AM Christoph Hellwig <hch at lst.de> wrote:
> >
> > Add a flag so that the file system can easily detect DAX operations.
> 
> Looks ok, but I would have preferred a quick note about the rationale
> here before needing to read other patches to figure that out.

The reason is to only apply the DAX partition offsets to actual DAX
operations, and not to e.g. fiemap.  I'll document that more clearly.