On Mon, Oct 13, 2014 at 5:12 PM, Trond Myklebust
<trond.myklebust@xxxxxxxxxxxxxxx> wrote:
> On Mon, Oct 13, 2014 at 4:23 PM, Olga Kornievskaia <aglo@xxxxxxxxx> wrote:
>> On Mon, Oct 13, 2014 at 3:53 PM, Trond Myklebust
>> <trond.myklebust@xxxxxxxxxxxxxxx> wrote:
>>> On Mon, Oct 13, 2014 at 2:51 PM, Olga Kornievskaia <aglo@xxxxxxxxx> wrote:
>>>> + }
>>>> + }
>>>> return nfs4_handle_delegation_recall_error(server, state, stateid, err);
>>>> }
>>>>
>>>> @@ -5957,6 +5973,10 @@ int nfs4_lock_delegation_recall(struct
>>>> file_lock *fl, struct nfs4_state *state,
>>>> err = nfs4_set_lock_state(state, fl);
>>>> if (err != 0)
>>>> return err;
>>>> + if (test_bit(NFS_LOCK_LOST, &fl->fl_u.nfs4_fl.owner->ls_flags)) {
>>>> + pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n",
>>>> __func__);
>>>> + return -EIO;
>>>> + }
>>>> err = _nfs4_do_setlk(state, F_SETLK, fl, NFS_LOCK_NEW);
>>>
>>> Note that there is a potential race here if the server is playing with
>>> NFS4ERR_DELEG_REVOKED or NFS4ERR_ADMIN_REVOKED. Since we do not
>>> present the delegation as part of the LOCK request, we have no way of
>>> knowing if the delegation is still in effect. I guess we can check the
>>> return value of DELEGRETURN, but if it returns NFS4ERR_DELEG_REVOKED
>>> or NFS4ERR_ADMIN_REVOKED, then we still do not know whether or not the
>>> LOCK is safe.
>>
>> I'm not following you. We send LOCK before we send DELEGRETURN? Also,
>> we normally send in LOCK the open_stateid returned by the open with
>> cur so do we know that delegation is still in effect.
>
> How so? The open stateid doesn't tell you that the delegation is still
> in effect. If the DELEGRETURN returns NFS4ERR_DELEG_REVOKED, how can
> you tell if the delegation was revoked before or after the LOCK
> request was handled?
Actually, let me answer that myself. You can sort of figure things out
in NFSv4.1 if you look at the SEQ4_STATUS_RECALLABLE_STATE_REVOKED
flag. If it is set, you should probably distrust the lock stateid that
you just attempted to recover, since you now know that at least one
delegation was just revoked.
In that case, we probably also have to do a TEST_STATEID+FREE_STATEID
on the delegation stateid.
--
Trond Myklebust
Linux NFS client maintainer, PrimaryData
trond.myklebust@xxxxxxxxxxxxxxx
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