Re: [RFC PATCH 09/09] Introduce cache=rdma moutning option

[Christoph Hellwig]

On Thu, May 17, 2018 at 05:22:14PM -0700, Long Li wrote:
> From: Long Li <longli@xxxxxxxxxxxxx>
> 
> When cache=rdma is enabled on mount options, CIFS do not allocate internal data
> buffer pages for I/O, data is read/writen directly to user memory via RDMA.

I don't think this should be an option.  For direct I/O without signing
or encryption CIFS should always use get_user_pages, with or without
RDMA.