NFSv4.1: Select the "most recent locking state" for read/write/setattr stateids

Follow the practice described in section 8.2.2 of RFC5661: When sending a
read/write or setattr stateid, set the seqid field to zero in order to
signal that the NFS server should apply the most recent locking state.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4state.c

@@ -1053,6 +1053,8 @@ int nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
 		goto out;
 	ret = nfs4_copy_open_stateid(dst, state);
 out:
+	if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
+		dst->seqid = 0;
 	return ret;
 }