On Thu, Feb 01, 2018 at 05:13:40PM -0700, Dave Jiang wrote:

On 02/01/2018 04:44 PM, Dave Chinner wrote:

quoted

On Thu, Feb 01, 2018 at 01:33:05PM -0700, Dave Jiang wrote:

quoted

When using realtime device (rtdev) with xfs where the data device is not
DAX capable, two issues arise. One is when data device is not DAX but the
realtime device is DAX capable, we currently disable DAX.
After passing this check, we are also not marking the inode as DAX capable.
This change will allow DAX enabled if the data device or the realtime
device is DAX capable. S_DAX will be marked for the inode if the file is
residing on a DAX capable device. This will prevent the case of rtdev is not
DAX and data device is DAX to create realtime files.

I'm confused by this description. I'm not sure what is broken, nor
what you are trying to fix.

I think what you want to do is enable DAX on RT devices separately
to the data device and vice versa?

i.e. is this what you are trying to acheive?

datadev dax	rtdev dax		DAX enabled on
-----------     ---------		--------------
no		no			neither
yes		no			datadev
no		yes			rtdev
yes		yes			both

^ Yes that's pretty much what I was trying to say. I probably should've
just provided the table above.

Ok, good to know I understood what you want to achieve. Now we've
just got to work out how to do it. :)

Cheers,

Dave.
-- 
Dave Chinner
david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org