On Wed, Dec 19, 2018 at 05:05:45PM -0500, Scott Mayhew wrote: > On Wed, 19 Dec 2018, J. Bruce Fields wrote: > > > On Tue, Dec 18, 2018 at 09:29:26AM -0500, Scott Mayhew wrote: > > > + if (!nfsd4_find_reclaim_client(clp->cl_name, nn)) > > > + return; > > > + if (atomic_inc_return(&nn->nr_reclaim_complete) == > > > + nn->reclaim_str_hashtbl_size) { > > > + printk(KERN_INFO "NFSD: all clients done reclaiming, ending NFSv4 grace period (net %x)\n", > > > + clp->net->ns.inum); > > > + nfsd4_end_grace(nn); > > > + } > > > +} > > > + > > > +static void dec_reclaim_complete(struct nfs4_client *clp) > > > +{ > > > + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); > > > + > > > + if (!nn->track_reclaim_completes) > > > + return; > > > + if (!test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &clp->cl_flags)) > > > + return; > > > + if (nfsd4_find_reclaim_client(clp->cl_name, nn)) > > > + atomic_dec(&nn->nr_reclaim_complete); > > > +} > > > + > > > static void expire_client(struct nfs4_client *clp) > > > { > > > unhash_client(clp); > > > nfsd4_client_record_remove(clp); > > > + dec_reclaim_complete(clp); > > > __destroy_client(clp); > > > } > > > > This doesn't look right to me. If a client reclaims and then > > immediately calls DESTROY_CLIENTID or something--that should still count > > as a reclaim, and that shouldn't prevent us from ending the grace period > > early. > > > > I think dec_reclaim_complete is unnecessary. > > What if a client sends a RECLAIM_COMPLETE, then reboots and sends an > EXCHANGE_ID, CREATE_SESSION, and RECLAIM_COMPLETE while the server is > still in grace? The count would be too high then and the server could > exit grace before all the clients have reclaimed. I actually added > that at Jeff's suggestion because he was seeing it with nfs-ganesha. Oh boy. (Thinks.) Once it issues a DESTROY_CLIENTID or an EXCHANGE_ID that removes the previous client instance's state, it's got no locks to reclaim any more. (It can't have gotten any *new* ones, since we're still in the grace period.) It's effectively a brand new client. Only reclaiming clients should bump that counter. We certainly shouldn't be waiting for it to RECLAIM_COMPLETE to end the grace period, that client just doesn't matter any more. I think? --b.