still nfs problems [Was: Linux 2.6.37-rc8]

[Russell King - ARM Linux]

On Fri, Jan 07, 2011 at 01:53:25PM -0500, Trond Myklebust wrote:
> I'd still like to keep the existing code for those architectures that
> don't have problems, since that allows us to send 32k READDIR requests
> instead of being limited to 4k. For large directories, that is a clear
> win.
> For the NOMMU case we will just go back to using a single page for
> storage (and 4k READDIR requests only). Should I just do the same for
> architectures like ARM and PARISC?

I think you said that readdir reads via the vmalloc mapping of the
group of pages, but XDR writes to the individual pages.

As I understand NFS, you receive a packet, you then have to use XDR
to unpack the data, which you presumably write into the set of
struct page *'s using kmap?

Isn't a solution to have XDR write directly into the vmalloc mapping
rather than using struct page * and kmap?