From: Trond Myklebust Subject: Re: [PATCH] sunrpc: on successful gss error pipe write, don't return error Date: Fri, 18 Dec 2009 10:12:22 -0500 Message-ID: <1261149142.3229.20.camel@localhost> References: <1261144574-1642-1-git-send-email-jlayton@redhat.com> <1261145468.3229.7.camel@localhost> <20091218093912.1c426ad6@tlielax.poochiereds.net> <1261147672.3229.14.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: linux-nfs@vger.kernel.org, nfsv4@linux-nfs.org To: Jeff Layton Return-path: Received: from mx2.netapp.com ([216.240.18.37]:50328 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754244AbZLRPMl convert rfc822-to-8bit (ORCPT ); Fri, 18 Dec 2009 10:12:41 -0500 In-Reply-To: <1261147672.3229.14.camel@localhost> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, 2009-12-18 at 09:47 -0500, Trond Myklebust wrote: > On Fri, 2009-12-18 at 09:39 -0500, Jeff Layton wrote: > > Without a separate downcall error field, we'll need to special case at > > least 2 different errors -- one for a "real" EACCES and one that > > indicates that the ticket expired and the upcall should be retried > > instead. > > We can find another error for the 'ticket expired' case. EKEYEXPIRED > springs to mind... BTW: Here be dragons! I think we need to handle the 'ticket expired' case as if it were an NFS4ERR_DELAY/EJUKEBOX, and actually do the retry in the NFS layer after a suitable exponential back-off period. Otherwise, we end up holding onto resources (in particular NFSv4.1 slots, but also RPC slots, ...) which will cause congestion, and prevent other RPC calls from making progress. Cheers Trond