On Mon, Aug 19, 2013 at 11:55:58AM -0400, Martin Hicks wrote: > Hi Bruce, > > On Fri, Aug 16, 2013 at 5:12 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > > On Thu, Aug 15, 2013 at 12:04:33PM -0400, Martin Hicks wrote: > >> I'm wondering if I'm missing something or if this is a bug. > >> > >> A NFS4 export has active clients. The mount is removed from > >> /etc/exports and 'exportfs -r' is run. Clients immediately start > >> getting 'Stale file handle' errors, but the mountpoint is still busy > >> and cannot be unmounted. Killing off nfsd solves the problem, but is > >> undesirable for obvious reasons. > >> > >> On debian linux, kernel version 3.10-2-amd64, with nfs-utils 1.2.8. > > > > Yeah, the clients may hold opens or locks on the filesystem and those > > don't get removed on exports -r. > > > > For now shutting down the server is the only solution. > > > > We could possibly fix that, or provide some other way to do whatever it > > is you're trying to do, but it's likely not a small change. > > Essentially I've got a NAS with two doors that have removable disks > behind them. I get a signal from hardware when one of the doors is > opened, and I need to kill services, unmount and remove the block > device very quickly so the user can remove or swap disks. I was > trying to avoid killing nfsd so that any clients connected to the > block device behind the other door could continue uninterrupted. OK, understood, so you're mainly worried about access to the remaining data continuing uniterrrupted. That said--it's *really* not a problem that the other stuff starts erroring out immediately? I imagine the typical application isn't going to handle the errors very gracefully. > If this isn't possible then I need to minimize the downtime to the > other disk. With quick experiements this morning if I simply restart > nfs it seems to take between 60 and 90 seconds for the client to start > doing IO again. I haven't tracked down the reason yet, but it seems > like the server is preventing the client from doing IO for some > time... It's probably the grace period (which will block pretty much any IO for clients using NFSv4). --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
