NFSv4: Fix hangs when recovering open state after a server reboot

When we're using a cached open stateid or a delegation in order to avoid
sending a CLAIM_PREVIOUS open RPC call to the server, we don't have a
new open stateid to present to update_open_stateid().
Instead rely on nfs4_try_open_cached(), just as if we were doing a
normal open.

Fixes: d2bfda2 ("NFSv4: don't reprocess cached open CLAIM_PREVIOUS")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

Author: Trond Myklebust

fs/nfs/nfs4proc.c

@@ -1980,8 +1980,7 @@ _nfs4_opendata_reclaim_to_nfs4_state(struct nfs4_opendata *data)
 	if (!data->rpc_done) {
 		if (data->rpc_status)
 			return ERR_PTR(data->rpc_status);
-		/* cached opens have already been processed */
-		goto update;
+		return nfs4_try_open_cached(data);
 	}
 
 	ret = nfs_refresh_inode(inode, &data->f_attr);
@@ -1990,7 +1989,7 @@ _nfs4_opendata_reclaim_to_nfs4_state(struct nfs4_opendata *data)
 
 	if (data->o_res.delegation_type != 0)
 		nfs4_opendata_check_deleg(data, state);
-update:
+
 	if (!update_open_stateid(state, &data->o_res.stateid,
 				NULL, data->o_arg.fmode))
 		return ERR_PTR(-EAGAIN);