Ok...  hot on the heels of the other GFP_ZONEMASK patch:

struct bootmem_data;
typedef struct pglist_data {
	struct zone node_zones[MAX_NR_ZONES];
	struct zonelist node_zonelists[GFP_ZONEMASK+1];
	int nr_zones;
	struct page *node_mem_map;
	unsigned long *valid_addr_bitmap;
	struct bootmem_data *bdata;
	unsigned long node_start_pfn;
	unsigned long node_size;
	int node_id;
	struct pglist_data *pgdat_next;
	wait_queue_head_t       kswapd_wait;
} pg_data_t;

node_zonelists looks like it should really be declared of size 
MAX_NR_ZONES, not GFP_ZONEMASK.  GFP_ZONEMASK is currently 15, making 
node_zonelists an array of 16 elements.  The extra zonelists are all 
just duplicates of the *real* zonelists, namely the first 3 entries. 
Again, if anyone can explain to me why I'm wrong in my thinking, I'd 
love to know.  There's certainly no way you could bitwise-and something 
with any combination of the GFP_DMA and GFP_HIGHMEM flags to refer to 
the 12th zonelist or some such!  Or am I crazy?

Cheers!

-Matt