Re: Ping: [pnfs] [RFC 1/1] nfs4: optionally return status from state_manager

[Benny Halevy <bhalevy@panasas.com>]

On Sep. 25, 2009, 17:10 +0300, "J. Bruce Fields" <bfields@citi.umich.edu> wrote:
> On Fri, Sep 25, 2009 at 04:53:17PM +0300, Benny Halevy wrote:
>> On 2009-09-25 16:29, Trond Myklebust wrote:
>>> On Fri, 2009-09-25 at 07:30 +0300, Benny Halevy wrote:
>>>> Trond,
>>>>
>>>> Is the patch below acceptable?
>>>>
>>>> Benny
>>> I'm still not entirely happy with the idea that the state manager can
>>> get into situations where it needs outside help, and you haven't really
>>> explained to me the root cause of the scenario.
>>> You said something about
>>>
>>> nfs4_create_server()
>>> nfs4_init_session()
>>> nfs4_recover_expired_lease()
>>>         nfs4_schedule_state_recovery()
>>>                 # and the failure happens within the state engine
>>>                 nfs4_proc_create_session()
>>>                 nfs4_proc_get_lease_time() return -2
>>>
>>> Where does that ENOENT come from?
>>>
>>> You said something about it being an error in OP_PUTROOTFH, but as far
>>> as I can see, the only permitted errors for putrootfh are either session
>>> related errors (which should be handled by the state machine),
>>> NFS4ERR_DELAY (which should be handled by the state machine) and
>>> NFS4ERR_WRONGSEC. So which error is generating your ENOENT?
>>>
>> That scenario is caused when the server's /etc/exports
>> is badly configured, where the export entry for nfsv4
>> (fsid=0) exports a non-existing path.
>>
>> I agree that the server should not return ENOENT
>> for PUTROOTFH as it contradicts the spec.
>> NFS4ERR_SERVERFAULT seems more appropriate.
>>
>> The main reason for getting the failure from
>> the state engine in nfsv4.1 is that we need to
>> create a session before nfs4_path_walk in nfs4_create_server
>> and we do that using the state manager.
>> In the nfsv4.0 case we create no state at this point.
> 
> So is there any actual client-side bug here?

The client side bug is returning an irrelevant
and confusing error status back to the application (mount.nfs4).

Benny

> 
> --b.