forked from Mirrors/btrfs-progs
78 lines
2.3 KiB
C
78 lines
2.3 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)
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{
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struct ctree_root_info info[2];
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struct leaf empty_leaf;
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struct item item;
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struct extent_item extent_item;
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int ret;
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/* setup the super block area */
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memset(info, 0, sizeof(info));
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info[0].blocknr = 16;
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info[0].objectid = 1;
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info[0].tree_root = 17;
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info[1].blocknr = 16;
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info[1].objectid = 2;
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info[1].tree_root = 18;
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ret = pwrite(fd, info, sizeof(info),
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CTREE_SUPER_INFO_OFFSET(CTREE_BLOCKSIZE));
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if (ret != sizeof(info))
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return -1;
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/* create leaves for the tree root and extent root */
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memset(&empty_leaf, 0, sizeof(empty_leaf));
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btrfs_set_header_parentid(&empty_leaf.header, 1);
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btrfs_set_header_blocknr(&empty_leaf.header, 17);
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ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 17 * CTREE_BLOCKSIZE);
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if (ret != sizeof(empty_leaf))
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return -1;
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btrfs_set_header_parentid(&empty_leaf.header, 2);
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btrfs_set_header_blocknr(&empty_leaf.header, 18);
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btrfs_set_header_nritems(&empty_leaf.header, 3);
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/* item1, reserve blocks 0-16 */
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item.key.objectid = cpu_to_le64(0);
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item.key.offset = cpu_to_le64(17);
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item.key.flags = cpu_to_le32(0);
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item.offset = LEAF_DATA_SIZE - sizeof(struct extent_item);
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item.size = sizeof(struct extent_item);
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extent_item.refs = 1;
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extent_item.owner = 0;
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memcpy(empty_leaf.items, &item, sizeof(item));
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memcpy(empty_leaf.data + item.offset, &extent_item, item.size);
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/* item2, give block 17 to the root */
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item.key.objectid = cpu_to_le64(17);
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item.key.offset = cpu_to_le64(1);
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item.offset = LEAF_DATA_SIZE - sizeof(struct extent_item) * 2;
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extent_item.owner = 1;
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memcpy(empty_leaf.items + 1, &item, sizeof(item));
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memcpy(empty_leaf.data + item.offset, &extent_item, item.size);
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/* item3, give block 18 for the extent root */
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item.key.objectid = cpu_to_le64(18);
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item.key.offset = cpu_to_le64(1);
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item.offset = LEAF_DATA_SIZE - sizeof(struct extent_item) * 3;
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extent_item.owner = 2;
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memcpy(empty_leaf.items + 2, &item, sizeof(item));
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memcpy(empty_leaf.data + item.offset, &extent_item, item.size);
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ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 18 * CTREE_BLOCKSIZE);
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if (ret != sizeof(empty_leaf))
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return -1;
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return 0;
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}
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