[linux-2.6-block.git] / fs / btrfs / mkfs.c

#define _XOPEN_SOURCE 500
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "kerncompat.h"
#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"

int mkfs(int fd, u64 num_blocks, u32 blocksize)
{
	struct btrfs_super_block super;
	struct btrfs_leaf *empty_leaf;
	struct btrfs_root_item root_item;
	struct btrfs_item item;
	struct btrfs_extent_item extent_item;
	char *block;
	int ret;
	u32 itemoff;
	u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize;

	btrfs_set_super_blocknr(&super, start_block);
	btrfs_set_super_root(&super, start_block + 1);
	strcpy((char *)(&super.magic), BTRFS_MAGIC);
	btrfs_set_super_blocksize(&super, blocksize);
	btrfs_set_super_total_blocks(&super, num_blocks);
	btrfs_set_super_blocks_used(&super, 0);

	block = malloc(blocksize);
	memset(block, 0, blocksize);
	BUG_ON(sizeof(super) > blocksize);
	memcpy(block, &super, sizeof(super));
	ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET);
	BUG_ON(ret != blocksize);

	/* create the tree of root objects */
	empty_leaf = malloc(blocksize);
	memset(empty_leaf, 0, blocksize);
	btrfs_set_header_parentid(&empty_leaf->header,
				  BTRFS_ROOT_TREE_OBJECTID);
	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 1);
	btrfs_set_header_nritems(&empty_leaf->header, 2);

	/* create the items for the root tree */
	btrfs_set_root_blocknr(&root_item, start_block + 2);
	btrfs_set_root_refs(&root_item, 1);
	itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item);
	btrfs_set_item_offset(&item, itemoff);
	btrfs_set_item_size(&item, sizeof(root_item));
	btrfs_set_disk_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
	btrfs_set_disk_key_offset(&item.key, 0);
	btrfs_set_disk_key_flags(&item.key, 0);
	btrfs_set_disk_key_type(&item.key, BTRFS_ROOT_ITEM_KEY);
	memcpy(empty_leaf->items, &item, sizeof(item));
	memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
		&root_item, sizeof(root_item));

	btrfs_set_root_blocknr(&root_item, start_block + 3);
	itemoff = itemoff - sizeof(root_item);
	btrfs_set_item_offset(&item, itemoff);
	btrfs_set_disk_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID);
	memcpy(empty_leaf->items + 1, &item, sizeof(item));
	memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
		&root_item, sizeof(root_item));
	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 1) * blocksize);

	/* create the items for the extent tree */
	btrfs_set_header_parentid(&empty_leaf->header,
				  BTRFS_EXTENT_TREE_OBJECTID);
	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 2);
	btrfs_set_header_nritems(&empty_leaf->header, 4);

	/* item1, reserve blocks 0-16 */
	btrfs_set_disk_key_objectid(&item.key, 0);
	btrfs_set_disk_key_offset(&item.key, start_block + 1);
	btrfs_set_disk_key_flags(&item.key, 0);
	btrfs_set_disk_key_type(&item.key, BTRFS_EXTENT_ITEM_KEY);
	itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) -
			sizeof(struct btrfs_extent_item);
	btrfs_set_item_offset(&item, itemoff);
	btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
	btrfs_set_extent_refs(&extent_item, 1);
	btrfs_set_extent_owner(&extent_item, 0);
	memcpy(empty_leaf->items, &item, sizeof(item));
	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
		&extent_item, btrfs_item_size(&item));

	/* item2, give block 17 to the root */
	btrfs_set_disk_key_objectid(&item.key, start_block + 1);
	btrfs_set_disk_key_offset(&item.key, 1);
	itemoff = itemoff - sizeof(struct btrfs_extent_item);
	btrfs_set_item_offset(&item, itemoff);
	btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID);
	memcpy(empty_leaf->items + 1, &item, sizeof(item));
	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
		&extent_item, btrfs_item_size(&item));

	/* item3, give block 18 to the extent root */
	btrfs_set_disk_key_objectid(&item.key, start_block + 2);
	btrfs_set_disk_key_offset(&item.key, 1);
	itemoff = itemoff - sizeof(struct btrfs_extent_item);
	btrfs_set_item_offset(&item, itemoff);
	btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID);
	memcpy(empty_leaf->items + 2, &item, sizeof(item));
	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
		&extent_item, btrfs_item_size(&item));

	/* item4, give block 19 to the FS root */
	btrfs_set_disk_key_objectid(&item.key, start_block + 3);
	btrfs_set_disk_key_offset(&item.key, 1);
	itemoff = itemoff - sizeof(struct btrfs_extent_item);
	btrfs_set_item_offset(&item, itemoff);
	btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID);
	memcpy(empty_leaf->items + 3, &item, sizeof(item));
	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
		&extent_item, btrfs_item_size(&item));
	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
	if (ret != blocksize)
		return -1;

	/* finally create the FS root */
	btrfs_set_header_parentid(&empty_leaf->header, BTRFS_FS_TREE_OBJECTID);
	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 3);
	btrfs_set_header_nritems(&empty_leaf->header, 0);
	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 3) * blocksize);
	if (ret != blocksize)
		return -1;
	return 0;
}
Commit	Line	Data
06ed4b31 CM	1	#define _XOPEN_SOURCE 500
	2	#include <stdio.h>
	3	#include <stdlib.h>
	4	#include <sys/types.h>
	5	#include <sys/stat.h>
	6	#include <fcntl.h>
	7	#include <unistd.h>
	8	#include "kerncompat.h"
	9	#include "radix-tree.h"
	10	#include "ctree.h"
	11	#include "disk-io.h"
	12
123abc88	13	int mkfs(int fd, u64 num_blocks, u32 blocksize)
3768f368 CM	14	{
3768f368 CM	15	struct btrfs_super_block super;
123abc88	16	struct btrfs_leaf *empty_leaf;
3768f368 CM	17	struct btrfs_root_item root_item;
	18	struct btrfs_item item;
	19	struct btrfs_extent_item extent_item;
	20	char *block;
	21	int ret;
123abc88 CM	22	u32 itemoff;
123abc88 CM	23	u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize;
3768f368	24
123abc88 CM	25	btrfs_set_super_blocknr(&super, start_block);
123abc88 CM	26	btrfs_set_super_root(&super, start_block + 1);
3768f368 CM	27	strcpy((char *)(&super.magic), BTRFS_MAGIC);
	28	btrfs_set_super_blocksize(&super, blocksize);
	29	btrfs_set_super_total_blocks(&super, num_blocks);
	30	btrfs_set_super_blocks_used(&super, 0);
	31
	32	block = malloc(blocksize);
	33	memset(block, 0, blocksize);
	34	BUG_ON(sizeof(super) > blocksize);
	35	memcpy(block, &super, sizeof(super));
123abc88	36	ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET);
3768f368 CM	37	BUG_ON(ret != blocksize);
	38
	39	/* create the tree of root objects */
123abc88 CM	40	empty_leaf = malloc(blocksize);
	41	memset(empty_leaf, 0, blocksize);
	42	btrfs_set_header_parentid(&empty_leaf->header,
	43	BTRFS_ROOT_TREE_OBJECTID);
	44	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 1);
	45	btrfs_set_header_nritems(&empty_leaf->header, 2);
3768f368 CM	46
3768f368 CM	47	/* create the items for the root tree */
123abc88	48	btrfs_set_root_blocknr(&root_item, start_block + 2);
3768f368	49	btrfs_set_root_refs(&root_item, 1);
123abc88	50	itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item);
3768f368 CM	51	btrfs_set_item_offset(&item, itemoff);
3768f368 CM	52	btrfs_set_item_size(&item, sizeof(root_item));
62e2749e CM	53	btrfs_set_disk_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
	54	btrfs_set_disk_key_offset(&item.key, 0);
	55	btrfs_set_disk_key_flags(&item.key, 0);
	56	btrfs_set_disk_key_type(&item.key, BTRFS_ROOT_ITEM_KEY);
123abc88 CM	57	memcpy(empty_leaf->items, &item, sizeof(item));
	58	memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
	59	&root_item, sizeof(root_item));
3768f368	60
123abc88	61	btrfs_set_root_blocknr(&root_item, start_block + 3);
3768f368 CM	62	itemoff = itemoff - sizeof(root_item);
3768f368 CM	63	btrfs_set_item_offset(&item, itemoff);
62e2749e	64	btrfs_set_disk_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID);
123abc88 CM	65	memcpy(empty_leaf->items + 1, &item, sizeof(item));
	66	memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
	67	&root_item, sizeof(root_item));
	68	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 1) * blocksize);
3768f368 CM	69
3768f368 CM	70	/* create the items for the extent tree */
123abc88	71	btrfs_set_header_parentid(&empty_leaf->header,
3768f368	72	BTRFS_EXTENT_TREE_OBJECTID);
123abc88 CM	73	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 2);
123abc88 CM	74	btrfs_set_header_nritems(&empty_leaf->header, 4);
3768f368 CM	75
3768f368 CM	76	/* item1, reserve blocks 0-16 */
62e2749e CM	77	btrfs_set_disk_key_objectid(&item.key, 0);
	78	btrfs_set_disk_key_offset(&item.key, start_block + 1);
	79	btrfs_set_disk_key_flags(&item.key, 0);
	80	btrfs_set_disk_key_type(&item.key, BTRFS_EXTENT_ITEM_KEY);
123abc88 CM	81	itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) -
123abc88 CM	82	sizeof(struct btrfs_extent_item);
3768f368 CM	83	btrfs_set_item_offset(&item, itemoff);
	84	btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
	85	btrfs_set_extent_refs(&extent_item, 1);
	86	btrfs_set_extent_owner(&extent_item, 0);
123abc88 CM	87	memcpy(empty_leaf->items, &item, sizeof(item));
	88	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
	89	&extent_item, btrfs_item_size(&item));
3768f368 CM	90
3768f368 CM	91	/* item2, give block 17 to the root */
62e2749e CM	92	btrfs_set_disk_key_objectid(&item.key, start_block + 1);
62e2749e CM	93	btrfs_set_disk_key_offset(&item.key, 1);
3768f368 CM	94	itemoff = itemoff - sizeof(struct btrfs_extent_item);
	95	btrfs_set_item_offset(&item, itemoff);
	96	btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID);
123abc88 CM	97	memcpy(empty_leaf->items + 1, &item, sizeof(item));
	98	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
	99	&extent_item, btrfs_item_size(&item));
3768f368 CM	100
3768f368 CM	101	/* item3, give block 18 to the extent root */
62e2749e CM	102	btrfs_set_disk_key_objectid(&item.key, start_block + 2);
62e2749e CM	103	btrfs_set_disk_key_offset(&item.key, 1);
3768f368 CM	104	itemoff = itemoff - sizeof(struct btrfs_extent_item);
	105	btrfs_set_item_offset(&item, itemoff);
	106	btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID);
123abc88 CM	107	memcpy(empty_leaf->items + 2, &item, sizeof(item));
	108	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
	109	&extent_item, btrfs_item_size(&item));
3768f368 CM	110
3768f368 CM	111	/* item4, give block 19 to the FS root */
62e2749e CM	112	btrfs_set_disk_key_objectid(&item.key, start_block + 3);
62e2749e CM	113	btrfs_set_disk_key_offset(&item.key, 1);
3768f368 CM	114	itemoff = itemoff - sizeof(struct btrfs_extent_item);
	115	btrfs_set_item_offset(&item, itemoff);
	116	btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID);
123abc88 CM	117	memcpy(empty_leaf->items + 3, &item, sizeof(item));
	118	memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
	119	&extent_item, btrfs_item_size(&item));
	120	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
	121	if (ret != blocksize)
3768f368 CM	122	return -1;
	123
	124	/* finally create the FS root */
123abc88 CM	125	btrfs_set_header_parentid(&empty_leaf->header, BTRFS_FS_TREE_OBJECTID);
	126	btrfs_set_header_blocknr(&empty_leaf->header, start_block + 3);
	127	btrfs_set_header_nritems(&empty_leaf->header, 0);
	128	ret = pwrite(fd, empty_leaf, blocksize, (start_block + 3) * blocksize);
	129	if (ret != blocksize)
3768f368 CM	130	return -1;
	131	return 0;
	132	}