Re: [PATCH 1/1] NFSD: fix error handling in callbacks

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

On Tue, Mar 09, 2021 at 02:45:19PM -0500, Scott Mayhew wrote:
> On Tue, 09 Mar 2021, J. Bruce Fields wrote:
> 
> > On Tue, Mar 09, 2021 at 09:41:27AM -0500, Olga Kornievskaia wrote:
> > > From: Olga Kornievskaia <kolga@netapp.com>
> > > 
> > > When the server tries to do a callback and a client fails it due to
> > > authentication problems, we need the server to set callback down
> > > flag in RENEW so that client can recover.
> > 
> > I was looking at this.  It looks to me like this should really be just:
> > 
> > 	case 1:
> > 		if (task->tk_status)
> > 			nfsd4_mark_cb_down(clp, task->tk_status);
> > 
> > If tk_status showed an error, and the ->done method doesn't return 0 to
> > tell us it something worth retrying, then the callback failed
> > permanently, so we should mark the callback path down, regardless of the
> > exact error.
> 
> That switch was added because the server was erroneously setting
> SEQ4_STATUS_CB_PATH_DOWN in the event that a client returned an
> NFS-level error for a CB_RECALL that the client had already done a
> FREE_STATEID for.  Removing the switch will cause the server to go back
> to that behaviour, won't it?

Oh, thanks for the history.

My knee-jerk reaction is: that sounds like a recall-specific issue, so
maybe that logic should be in nfsd4_cb_recall_done?

I guess I'm OK continuing instead to enumerate transport-layer errors in
nfsd4_cb_done, but do we know that EACCES makes it a complete list?

--b.

> 
> -Scott
> > 
> > --b.
> > 
> > > 
> > > Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> > > ---
> > >  fs/nfsd/nfs4callback.c | 1 +
> > >  1 file changed, 1 insertion(+)
> > > 
> > > diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
> > > index 052be5bf9ef5..7325592b456e 100644
> > > --- a/fs/nfsd/nfs4callback.c
> > > +++ b/fs/nfsd/nfs4callback.c
> > > @@ -1189,6 +1189,7 @@ static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
> > >  		switch (task->tk_status) {
> > >  		case -EIO:
> > >  		case -ETIMEDOUT:
> > > +		case -EACCES:
> > >  			nfsd4_mark_cb_down(clp, task->tk_status);
> > >  		}
> > >  		break;
> > > -- 
> > > 2.27.0
> > > 
> >