From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [PATCH 17/18] xfs: implement pnfs export operations Date: Mon, 12 Jan 2015 14:04:01 +1100 Message-ID: <20150112030401.GA29484@destitution> References: <1420561721-9150-1-git-send-email-hch@lst.de> <1420561721-9150-18-git-send-email-hch@lst.de> <20150107002434.GG31508@dastard> <20150107104010.GD28783@lst.de> <20150107211140.GC25000@dastard> <20150108124327.GA15222@lst.de> <20150108210405.GG25000@dastard> <20150109114159.GA25728@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "J. Bruce Fields" , Jeff Layton , linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, xfs-VZNHf3L845pBDgjK7y7TUQ@public.gmane.org To: Christoph Hellwig Return-path: Content-Disposition: inline In-Reply-To: <20150109114159.GA25728-jcswGhMUV9g@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Fri, Jan 09, 2015 at 12:41:59PM +0100, Christoph Hellwig wrote: > On Fri, Jan 09, 2015 at 08:04:05AM +1100, Dave Chinner wrote: > > > If the client sends the opaqueue device ID that contains the generation > > > after the grow to a server that had crashed / restarted the server > > > will reject it as the server starts at zero. The causes the client > > > to get a new, valid device ID from the server. > > > > But if the server fs has a generation number of zero when it > > crashes, how does the client tell that it needs a new device ID from > > the server? > > > > > Unlike the NFS file hadles which are persistent the device IDs are volatile > > > handles that can go away (and have really horrible life time rules..). > > > > Right. How the clients detect that "going away" when the device > > generation is zero both before and after a server crash is the > > question I'm asking.... > > The server tells the client by rejecting the operation using the > device ID. Ok, so: client server get layout dev id == 0 grow gen++ (=1) crash .... gen = 0 (initialised after boot) commit layout dev id == 0 server executes op, even though device has changed.... What prevents this? Shouldn't the server be rejecting the commit layout operation as there was a grow operation between the client operations? Cheers, Dave. -- Dave Chinner david-FqsqvQoI3Ljby3iVrkZq2A@public.gmane.org -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html