what happened to byte-addressable read()/write() to character device DAX?

Hi, Dan, Referring to   https://patchwork.kernel.org/project/linux-nvdimm/list/?page=6   [RFC,2/2] mm, fs: daxfile, an interface for byte-addressable updates to pmem I'm unable to find the patch in Linux upstream kernel, and am wondering if there has been a change of plan for providing support to byte granularity read() and write() to character device /dev/dax. I've also just started following the email threads, so I might have missed some critical discussions.  Would you mind to elaborate what's happening to the proposed feature? Thanks a lot! Regards, -jane