{
        __be32 *p;
 
-       RESERVE_SPACE(8+sizeof(arg->stateid->data));
+       RESERVE_SPACE(8+NFS4_STATEID_SIZE);
        WRITE32(OP_CLOSE);
        WRITE32(arg->seqid->sequence->counter);
-       WRITEMEM(arg->stateid->data, sizeof(arg->stateid->data));
+       WRITEMEM(arg->stateid->data, NFS4_STATEID_SIZE);
        
        return 0;
 }
        WRITE64(nfs4_lock_length(args->fl));
        WRITE32(args->new_lock_owner);
        if (args->new_lock_owner){
-               RESERVE_SPACE(40);
+               RESERVE_SPACE(4+NFS4_STATEID_SIZE+20);
                WRITE32(args->open_seqid->sequence->counter);
-               WRITEMEM(args->open_stateid->data, sizeof(args->open_stateid->data));
+               WRITEMEM(args->open_stateid->data, NFS4_STATEID_SIZE);
                WRITE32(args->lock_seqid->sequence->counter);
                WRITE64(args->lock_owner.clientid);
                WRITE32(4);
                WRITE32(args->lock_owner.id);
        }
        else {
-               RESERVE_SPACE(20);
-               WRITEMEM(args->lock_stateid->data, sizeof(args->lock_stateid->data));
+               RESERVE_SPACE(NFS4_STATEID_SIZE+4);
+               WRITEMEM(args->lock_stateid->data, NFS4_STATEID_SIZE);
                WRITE32(args->lock_seqid->sequence->counter);
        }
 
 {
        __be32 *p;
 
-       RESERVE_SPACE(44);
+       RESERVE_SPACE(12+NFS4_STATEID_SIZE+16);
        WRITE32(OP_LOCKU);
        WRITE32(nfs4_lock_type(args->fl, 0));
        WRITE32(args->seqid->sequence->counter);
-       WRITEMEM(args->stateid->data, sizeof(args->stateid->data));
+       WRITEMEM(args->stateid->data, NFS4_STATEID_SIZE);
        WRITE64(args->fl->fl_start);
        WRITE64(nfs4_lock_length(args->fl));
 
 {
        __be32 *p;
 
-       RESERVE_SPACE(4+sizeof(stateid->data));
+       RESERVE_SPACE(4+NFS4_STATEID_SIZE);
        WRITE32(NFS4_OPEN_CLAIM_DELEGATE_CUR);
-       WRITEMEM(stateid->data, sizeof(stateid->data));
+       WRITEMEM(stateid->data, NFS4_STATEID_SIZE);
        encode_string(xdr, name->len, name->name);
 }
 
 {
        __be32 *p;
 
-       RESERVE_SPACE(8+sizeof(arg->stateid->data));
+       RESERVE_SPACE(4+NFS4_STATEID_SIZE+4);
        WRITE32(OP_OPEN_CONFIRM);
-       WRITEMEM(arg->stateid->data, sizeof(arg->stateid->data));
+       WRITEMEM(arg->stateid->data, NFS4_STATEID_SIZE);
        WRITE32(arg->seqid->sequence->counter);
 
        return 0;
 {
        __be32 *p;
 
-       RESERVE_SPACE(8+sizeof(arg->stateid->data));
+       RESERVE_SPACE(4+NFS4_STATEID_SIZE+4);
        WRITE32(OP_OPEN_DOWNGRADE);
-       WRITEMEM(arg->stateid->data, sizeof(arg->stateid->data));
+       WRITEMEM(arg->stateid->data, NFS4_STATEID_SIZE);
        WRITE32(arg->seqid->sequence->counter);
        encode_share_access(xdr, arg->open_flags);
        return 0;
        nfs4_stateid stateid;
        __be32 *p;
 
-       RESERVE_SPACE(16);
+       RESERVE_SPACE(NFS4_STATEID_SIZE);
        if (ctx->state != NULL) {
                nfs4_copy_stateid(&stateid, ctx->state, ctx->lockowner);
-               WRITEMEM(stateid.data, sizeof(stateid.data));
+               WRITEMEM(stateid.data, NFS4_STATEID_SIZE);
        } else
-               WRITEMEM(zero_stateid.data, sizeof(zero_stateid.data));
+               WRITEMEM(zero_stateid.data, NFS4_STATEID_SIZE);
 }
 
 static int encode_read(struct xdr_stream *xdr, const struct nfs_readargs *args)
        int replen;
        __be32 *p;
 
-       RESERVE_SPACE(32+sizeof(nfs4_verifier));
+       RESERVE_SPACE(12+NFS4_VERIFIER_SIZE+20);
        WRITE32(OP_READDIR);
        WRITE64(readdir->cookie);
-       WRITEMEM(readdir->verifier.data, sizeof(readdir->verifier.data));
+       WRITEMEM(readdir->verifier.data, NFS4_VERIFIER_SIZE);
        WRITE32(readdir->count >> 1);  /* We're not doing readdirplus */
        WRITE32(readdir->count);
        WRITE32(2);
 {
        __be32 *p;
 
-       RESERVE_SPACE(4+sizeof(zero_stateid.data));
+       RESERVE_SPACE(4+NFS4_STATEID_SIZE);
        WRITE32(OP_SETATTR);
-       WRITEMEM(zero_stateid.data, sizeof(zero_stateid.data));
+       WRITEMEM(zero_stateid.data, NFS4_STATEID_SIZE);
        RESERVE_SPACE(2*4);
        WRITE32(1);
        WRITE32(FATTR4_WORD0_ACL);
        int status;
        __be32 *p;
        
-        RESERVE_SPACE(4+sizeof(arg->stateid.data));
+        RESERVE_SPACE(4+NFS4_STATEID_SIZE);
         WRITE32(OP_SETATTR);
-       WRITEMEM(arg->stateid.data, sizeof(arg->stateid.data));
+       WRITEMEM(arg->stateid.data, NFS4_STATEID_SIZE);
 
         if ((status = encode_attrs(xdr, arg->iap, server)))
                return status;
 {
        __be32 *p;
 
-       RESERVE_SPACE(4 + sizeof(setclientid->sc_verifier->data));
+       RESERVE_SPACE(4 + NFS4_VERIFIER_SIZE);
        WRITE32(OP_SETCLIENTID);
-       WRITEMEM(setclientid->sc_verifier->data, sizeof(setclientid->sc_verifier->data));
+       WRITEMEM(setclientid->sc_verifier->data, NFS4_VERIFIER_SIZE);
 
        encode_string(xdr, setclientid->sc_name_len, setclientid->sc_name);
        RESERVE_SPACE(4);
 {
         __be32 *p;
 
-        RESERVE_SPACE(12 + sizeof(client_state->cl_confirm.data));
+        RESERVE_SPACE(12 + NFS4_VERIFIER_SIZE);
         WRITE32(OP_SETCLIENTID_CONFIRM);
         WRITE64(client_state->cl_clientid);
-        WRITEMEM(client_state->cl_confirm.data, sizeof(client_state->cl_confirm.data));
+        WRITEMEM(client_state->cl_confirm.data, NFS4_VERIFIER_SIZE);
 
         return 0;
 }
 {
        __be32 *p;
 
-       RESERVE_SPACE(20);
+       RESERVE_SPACE(4+NFS4_STATEID_SIZE);
 
        WRITE32(OP_DELEGRETURN);
-       WRITEMEM(stateid->data, sizeof(stateid->data));
+       WRITEMEM(stateid->data, NFS4_STATEID_SIZE);
        return 0;
 
 }
        status = decode_op_hdr(xdr, OP_CLOSE);
        if (status)
                return status;
-       READ_BUF(sizeof(res->stateid.data));
-       COPYMEM(res->stateid.data, sizeof(res->stateid.data));
+       READ_BUF(NFS4_STATEID_SIZE);
+       COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
        return 0;
 }
 
 
        status = decode_op_hdr(xdr, OP_LOCK);
        if (status == 0) {
-               READ_BUF(sizeof(res->stateid.data));
-               COPYMEM(res->stateid.data, sizeof(res->stateid.data));
+               READ_BUF(NFS4_STATEID_SIZE);
+               COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
        } else if (status == -NFS4ERR_DENIED)
                return decode_lock_denied(xdr, NULL);
        return status;
 
        status = decode_op_hdr(xdr, OP_LOCKU);
        if (status == 0) {
-               READ_BUF(sizeof(res->stateid.data));
-               COPYMEM(res->stateid.data, sizeof(res->stateid.data));
+               READ_BUF(NFS4_STATEID_SIZE);
+               COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
        }
        return status;
 }
                res->delegation_type = 0;
                return 0;
        }
-       READ_BUF(20);
-       COPYMEM(res->delegation.data, sizeof(res->delegation.data));
+       READ_BUF(NFS4_STATEID_SIZE+4);
+       COPYMEM(res->delegation.data, NFS4_STATEID_SIZE);
        READ32(res->do_recall);
        switch (delegation_type) {
                case NFS4_OPEN_DELEGATE_READ:
         status = decode_op_hdr(xdr, OP_OPEN);
         if (status)
                 return status;
-        READ_BUF(sizeof(res->stateid.data));
-        COPYMEM(res->stateid.data, sizeof(res->stateid.data));
+        READ_BUF(NFS4_STATEID_SIZE);
+        COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
 
         decode_change_info(xdr, &res->cinfo);
 
         status = decode_op_hdr(xdr, OP_OPEN_CONFIRM);
         if (status)
                 return status;
-        READ_BUF(sizeof(res->stateid.data));
-        COPYMEM(res->stateid.data, sizeof(res->stateid.data));
+        READ_BUF(NFS4_STATEID_SIZE);
+        COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
         return 0;
 }
 
        status = decode_op_hdr(xdr, OP_OPEN_DOWNGRADE);
        if (status)
                return status;
-       READ_BUF(sizeof(res->stateid.data));
-       COPYMEM(res->stateid.data, sizeof(res->stateid.data));
+       READ_BUF(NFS4_STATEID_SIZE);
+       COPYMEM(res->stateid.data, NFS4_STATEID_SIZE);
        return 0;
 }
 
        }
        READ32(nfserr);
        if (nfserr == NFS_OK) {
-               READ_BUF(8 + sizeof(clp->cl_confirm.data));
+               READ_BUF(8 + NFS4_VERIFIER_SIZE);
                READ64(clp->cl_clientid);
-               COPYMEM(clp->cl_confirm.data, sizeof(clp->cl_confirm.data));
+               COPYMEM(clp->cl_confirm.data, NFS4_VERIFIER_SIZE);
        } else if (nfserr == NFSERR_CLID_INUSE) {
                uint32_t len;