282 	void *nat_block, *zero_block;  in shrink_nats()  local
288 	nat_block = malloc(BLOCK_SZ);  in shrink_nats()
289 	ASSERT(nat_block);  in shrink_nats()
307 		ret = dev_read_block(nat_block, block_addr);  in shrink_nats()
310 		if (memcmp(zero_block, nat_block, BLOCK_SZ)) {  in shrink_nats()
318 	free(nat_block);  in shrink_nats()
331 	void *nat_block;  in migrate_nat()  local
337 	nat_block = malloc(BLOCK_SZ);  in migrate_nat()
338 	ASSERT(nat_block);  in migrate_nat()
353 		ret = dev_read_block(nat_block, block_addr);  in migrate_nat()
361 		ret = dev_write_block(nat_block, block_addr);  in migrate_nat()
365 	memset(nat_block, 0, BLOCK_SZ);  in migrate_nat()
382 		ret = dev_write_block(nat_block, block_addr);  in migrate_nat()