Re: [nfsv4] 3530bis Issue 37: More ops need to be able to return LEASE_MOVED

[Robert Thurlow <[e-mail]>]

Robert Thurlow wrote:
> Hi folks,
> 
> This is issue 37 from 
> http://github.com/loghyr/3530bis/blob/master/tasklist.txt.
> 
> In implementing NFSv4 migration support, we ran into a few more
> ops which we believe should be able to return NFS4ERR_LEASE_MOVED.
> The reason we have LEASE_MOVED is to notify the client that some
> other filesystem it has used has migrated, and that it should react
> to that to preserve its state.  Operations which include state
> tokens should help with notification by failing with LEASE_MOVED.
> 
> The following OPs use state but do not now return LEASE_MOVED:
>         OPEN_CONFIRM
>         OPEN_DOWNGRADE
>         SETATTR (when the file size is set)
> 
> IIRC from the 3530bis call, there were questions about whether
> it was a good idea for OPEN_CONFIRM to return LEASE_MOVED.  I
> believe it is, since state is used in the operation.  A possible
> counter-argument is that delay can be inserted between OPEN and
> OPEN_CONFIRM for LEASE_MOVED handling, leading to unconfirmed
> open state being discarded, which is at least inconvenient.  A
> server could of course choose to extend timeouts for a client
> that had been sent a LEASE_MOVED notification.
> 
> If someone remembers a reason why one of these ops should not
> return LEASE_MOVED, or you wish to comment on the above, please
> let us know.

I don't think this has had a response.  If you disagree,
now's the time to speak up.

Rob T