163 lines
6.2 KiB
C
163 lines
6.2 KiB
C
#define _XOPEN_SOURCE 500
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include "kerncompat.h"
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#include "radix-tree.h"
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#include "ctree.h"
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#include "disk-io.h"
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int mkfs(int fd, u64 num_blocks, u32 blocksize)
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{
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struct btrfs_super_block super;
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struct btrfs_leaf *empty_leaf;
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struct btrfs_root_item root_item;
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struct btrfs_item item;
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struct btrfs_extent_item extent_item;
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char *block;
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int ret;
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u32 itemoff;
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u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize;
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btrfs_set_super_blocknr(&super, start_block);
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btrfs_set_super_root(&super, start_block + 1);
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strcpy((char *)(&super.magic), BTRFS_MAGIC);
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btrfs_set_super_blocksize(&super, blocksize);
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btrfs_set_super_total_blocks(&super, num_blocks);
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btrfs_set_super_blocks_used(&super, 0);
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block = malloc(blocksize);
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memset(block, 0, blocksize);
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BUG_ON(sizeof(super) > blocksize);
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memcpy(block, &super, sizeof(super));
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ret = pwrite(fd, block, blocksize, BTRFS_SUPER_INFO_OFFSET);
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BUG_ON(ret != blocksize);
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/* create the tree of root objects */
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empty_leaf = malloc(blocksize);
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memset(empty_leaf, 0, blocksize);
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btrfs_set_header_parentid(&empty_leaf->header,
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BTRFS_ROOT_TREE_OBJECTID);
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btrfs_set_header_blocknr(&empty_leaf->header, start_block + 1);
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btrfs_set_header_nritems(&empty_leaf->header, 3);
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/* create the items for the root tree */
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btrfs_set_root_blocknr(&root_item, start_block + 2);
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btrfs_set_root_refs(&root_item, 1);
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itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_item_size(&item, sizeof(root_item));
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btrfs_set_disk_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
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btrfs_set_disk_key_offset(&item.key, 0);
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btrfs_set_disk_key_flags(&item.key, 0);
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btrfs_set_disk_key_type(&item.key, BTRFS_ROOT_ITEM_KEY);
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memcpy(empty_leaf->items, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
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&root_item, sizeof(root_item));
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btrfs_set_root_blocknr(&root_item, start_block + 3);
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itemoff = itemoff - sizeof(root_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_disk_key_objectid(&item.key, BTRFS_INODE_MAP_OBJECTID);
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memcpy(empty_leaf->items + 1, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
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&root_item, sizeof(root_item));
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btrfs_set_root_blocknr(&root_item, start_block + 4);
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itemoff = itemoff - sizeof(root_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_disk_key_objectid(&item.key, BTRFS_FS_TREE_OBJECTID);
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memcpy(empty_leaf->items + 2, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + itemoff,
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&root_item, sizeof(root_item));
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ret = pwrite(fd, empty_leaf, blocksize, (start_block + 1) * blocksize);
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/* create the items for the extent tree */
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btrfs_set_header_parentid(&empty_leaf->header,
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BTRFS_EXTENT_TREE_OBJECTID);
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btrfs_set_header_blocknr(&empty_leaf->header, start_block + 2);
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btrfs_set_header_nritems(&empty_leaf->header, 5);
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/* item1, reserve blocks 0-16 */
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btrfs_set_disk_key_objectid(&item.key, 0);
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btrfs_set_disk_key_offset(&item.key, start_block + 1);
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btrfs_set_disk_key_flags(&item.key, 0);
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btrfs_set_disk_key_type(&item.key, BTRFS_EXTENT_ITEM_KEY);
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itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) -
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sizeof(struct btrfs_extent_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_item_size(&item, sizeof(struct btrfs_extent_item));
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btrfs_set_extent_refs(&extent_item, 1);
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btrfs_set_extent_owner(&extent_item, 0);
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memcpy(empty_leaf->items, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
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&extent_item, btrfs_item_size(&item));
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/* item2, give block 17 to the root */
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btrfs_set_disk_key_objectid(&item.key, start_block + 1);
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btrfs_set_disk_key_offset(&item.key, 1);
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itemoff = itemoff - sizeof(struct btrfs_extent_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_extent_owner(&extent_item, BTRFS_ROOT_TREE_OBJECTID);
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memcpy(empty_leaf->items + 1, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
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&extent_item, btrfs_item_size(&item));
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/* item3, give block 18 to the extent root */
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btrfs_set_disk_key_objectid(&item.key, start_block + 2);
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btrfs_set_disk_key_offset(&item.key, 1);
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itemoff = itemoff - sizeof(struct btrfs_extent_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_extent_owner(&extent_item, BTRFS_EXTENT_TREE_OBJECTID);
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memcpy(empty_leaf->items + 2, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
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&extent_item, btrfs_item_size(&item));
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/* item4, give block 19 to the inode map */
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btrfs_set_disk_key_objectid(&item.key, start_block + 3);
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btrfs_set_disk_key_offset(&item.key, 1);
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itemoff = itemoff - sizeof(struct btrfs_extent_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_extent_owner(&extent_item, BTRFS_INODE_MAP_OBJECTID);
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memcpy(empty_leaf->items + 3, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
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&extent_item, btrfs_item_size(&item));
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ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
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if (ret != blocksize)
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return -1;
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/* item5, give block 20 to the FS root */
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btrfs_set_disk_key_objectid(&item.key, start_block + 4);
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btrfs_set_disk_key_offset(&item.key, 1);
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itemoff = itemoff - sizeof(struct btrfs_extent_item);
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btrfs_set_item_offset(&item, itemoff);
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btrfs_set_extent_owner(&extent_item, BTRFS_FS_TREE_OBJECTID);
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memcpy(empty_leaf->items + 4, &item, sizeof(item));
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memcpy(btrfs_leaf_data(empty_leaf) + btrfs_item_offset(&item),
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&extent_item, btrfs_item_size(&item));
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ret = pwrite(fd, empty_leaf, blocksize, (start_block + 2) * blocksize);
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if (ret != blocksize)
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return -1;
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/* create the inode map */
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btrfs_set_header_parentid(&empty_leaf->header,
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BTRFS_INODE_MAP_OBJECTID);
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btrfs_set_header_blocknr(&empty_leaf->header, start_block + 3);
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btrfs_set_header_nritems(&empty_leaf->header, 0);
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ret = pwrite(fd, empty_leaf, blocksize, (start_block + 3) * blocksize);
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if (ret != blocksize)
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return -1;
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/* finally create the FS root */
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btrfs_set_header_parentid(&empty_leaf->header, BTRFS_FS_TREE_OBJECTID);
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btrfs_set_header_blocknr(&empty_leaf->header, start_block + 4);
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btrfs_set_header_nritems(&empty_leaf->header, 0);
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ret = pwrite(fd, empty_leaf, blocksize, (start_block + 4) * blocksize);
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if (ret != blocksize)
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return -1;
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return 0;
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}
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