NFSv4: Don't call nfs4_reclaim_complete() on receiving NFS4ERR_STALE_CLIENTID

If the server sends us an NFS4ERR_STALE_CLIENTID while the state management
thread is busy reclaiming state, we do want to treat all state that wasn't
reclaimed before the STALE_CLIENTID as if a network partition occurred (see
the edge conditions described in RFC3530 and RFC5661).
What we do not want to do is to send an nfs4_reclaim_complete(), since we
haven't yet even started reclaiming state after the server rebooted.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

fs/nfs/nfs4state.c

@@ -1138,16 +1138,14 @@ static void nfs4_reclaim_complete(struct nfs_client *clp,
 		(void)ops->reclaim_complete(clp);
 }
 
-static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
+static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
 {
 	struct nfs4_state_owner *sp;
 	struct rb_node *pos;
 	struct nfs4_state *state;
 
 	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
-		return;
-
-	nfs4_reclaim_complete(clp, clp->cl_mvops->reboot_recovery_ops);
+		return 0;
 
 	for (pos = rb_first(&clp->cl_state_owners); pos != NULL; pos = rb_next(pos)) {
 		sp = rb_entry(pos, struct nfs4_state_owner, so_client_node);
@@ -1161,6 +1159,14 @@ static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
 	}
 
 	nfs_delegation_reap_unclaimed(clp);
+	return 1;
+}
+
+static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
+{
+	if (!nfs4_state_clear_reclaim_reboot(clp))
+		return;
+	nfs4_reclaim_complete(clp, clp->cl_mvops->reboot_recovery_ops);
 }
 
 static void nfs_delegation_clear_all(struct nfs_client *clp)
@@ -1187,7 +1193,7 @@ static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
 		case -NFS4ERR_STALE_CLIENTID:
 		case -NFS4ERR_LEASE_MOVED:
 			set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
-			nfs4_state_end_reclaim_reboot(clp);
+			nfs4_state_clear_reclaim_reboot(clp);
 			nfs4_state_start_reclaim_reboot(clp);
 			break;
 		case -NFS4ERR_EXPIRED: