Re: [RFC v1 00/17] NFSD support for inter+async COPY

["J. Bruce Fields" <bfields@redhat.com>]

On Fri, Sep 01, 2017 at 04:02:48PM -0400, Olga Kornievskaia wrote:
> 
> > On Sep 1, 2017, at 3:53 PM, J. Bruce Fields <bfields@redhat.com> wrote:
> > 
> > On Fri, Sep 01, 2017 at 03:48:33PM -0400, Olga Kornievskaia wrote:
> >> On Fri, Sep 1, 2017 at 3:41 PM, J. Bruce Fields <bfields@redhat.com> wrote:
> >>>        - what currently happens if you try to copy across krb5 mounts?
> >> 
> >> No GSSv3 is included in these patches.  The destination server will
> >> mount the source server using auth_sys.
> > 
> > Assuming that doesn't work--how is the failure handled?
> 
> If mount fails? Destination server returns an error in COPY (whatever
>  vfs_kern_mount can return). Client calls generic nfs4_handle_exception() 
> but it’s probably a kind of error it doesn’t handle so it’ll be translated to EIO. 
> What kind of error are you thinking about?

I just want to make sure that copy_file_range() caller knows what to do
when it encounters this situation.

The typical application probably wants to fall back on a read-write loop
in the case inter-server copy isn't supported between the given mounts?

EIO doesn't sound like the most helpful error to me, but whatever error
it is, it should be documented in the copy_file_range man page so that
callers know how to check for this case.

--b.