Re: [RFC PATCH 00/09] Implement direct user I/O interfaces for RDMA

[Christoph Hellwig]

On Fri, May 18, 2018 at 06:03:09AM +0000, Long Li wrote:
> I also want to point out that, I choose to implement .read_iter and .write_iter from file_operations to implement direct I/O (CIFS is already doing this for O_DIRECT, so following this code path will avoid a big mess up).  The ideal choice is to implement .direct_IO from address_space_operations that I think eventually we want to move to.

No, the direct_IO address space operation is the mess.  We're moving
away from it.