btrfs-progs/mkfs.c

396 lines
12 KiB
C

/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#define _XOPEN_SOURCE 500
#ifndef __CHECKER__
#include <sys/ioctl.h>
#include <sys/mount.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <uuid/uuid.h>
#include "radix-tree.h"
#include <linux/fs.h>
#include "kerncompat.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#ifdef __CHECKER__
#define BLKGETSIZE64 0
static inline int ioctl(int fd, int define, u64 *size) { return 0; }
#endif
static int __make_root_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid)
{
int ret;
char buf[8];
struct btrfs_key inode_map;
struct btrfs_inode_item inode_item;
buf[0] = '.';
buf[1] = '.';
inode_map.objectid = objectid;
inode_map.flags = 0;
btrfs_set_key_type(&inode_map, BTRFS_INODE_ITEM_KEY);
inode_map.offset = 0;
memset(&inode_item, 0, sizeof(inode_item));
btrfs_set_inode_generation(&inode_item, root->fs_info->generation);
btrfs_set_inode_size(&inode_item, 6);
btrfs_set_inode_nlink(&inode_item, 1);
btrfs_set_inode_nblocks(&inode_item, 1);
btrfs_set_inode_mode(&inode_item, S_IFDIR | 0555);
if (root->fs_info->tree_root == root)
btrfs_set_super_root_dir(root->fs_info->disk_super, objectid);
ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
if (ret)
goto error;
ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
&inode_map, BTRFS_FT_DIR);
if (ret)
goto error;
ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
&inode_map, BTRFS_FT_DIR);
if (ret)
goto error;
btrfs_set_root_dirid(&root->root_item, objectid);
ret = 0;
error:
return ret;
}
static int make_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
u64 group_size_blocks;
u64 total_blocks;
u64 cur_start;
int ret;
u64 nr = 0;
struct btrfs_block_group_cache *cache;
root = root->fs_info->extent_root;
/* first we bootstrap the things into cache */
group_size_blocks = BTRFS_BLOCK_GROUP_SIZE / root->blocksize;
cache = malloc(sizeof(*cache));
cache->key.objectid = 0;
cache->key.offset = group_size_blocks;
cache->key.flags = 0;
btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
memset(&cache->item, 0, sizeof(cache->item));
btrfs_set_block_group_used(&cache->item,
btrfs_super_blocks_used(root->fs_info->disk_super));
ret = radix_tree_insert(&root->fs_info->block_group_radix,
group_size_blocks - 1, (void *)cache);
BUG_ON(ret);
total_blocks = btrfs_super_total_blocks(root->fs_info->disk_super);
cur_start = group_size_blocks;
while(cur_start < total_blocks) {
cache = malloc(sizeof(*cache));
cache->key.objectid = cur_start;
cache->key.offset = group_size_blocks;
cache->key.flags = 0;
btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY);
memset(&cache->item, 0, sizeof(cache->item));
if (nr % 3)
cache->item.flags |= BTRFS_BLOCK_GROUP_DATA;
ret = radix_tree_insert(&root->fs_info->block_group_radix,
cur_start + group_size_blocks - 1,
(void *)cache);
BUG_ON(ret);
cur_start += group_size_blocks;
nr++;
}
/* then insert all the items */
cur_start = 0;
while(cur_start < total_blocks) {
cache = radix_tree_lookup(&root->fs_info->block_group_radix,
cur_start + group_size_blocks - 1);
BUG_ON(!cache);
ret = btrfs_insert_block_group(trans, root, &cache->key,
&cache->item);
BUG_ON(ret);
cur_start += group_size_blocks;
}
return 0;
}
static int make_root_dir(int fd) {
struct btrfs_root *root;
struct btrfs_super_block super;
struct btrfs_trans_handle *trans;
int ret;
struct btrfs_key location;
root = open_ctree_fd(fd, &super);
if (!root) {
fprintf(stderr, "ctree init failed\n");
return -1;
}
trans = btrfs_start_transaction(root, 1);
ret = make_block_groups(trans, root);
ret = __make_root_dir(trans, root->fs_info->tree_root,
BTRFS_ROOT_TREE_DIR_OBJECTID);
if (ret)
goto err;
ret = __make_root_dir(trans, root, BTRFS_FIRST_FREE_OBJECTID);
if (ret)
goto err;
memcpy(&location, &root->fs_info->fs_root->root_key, sizeof(location));
location.offset = (u64)-1;
ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
"default", strlen("default"),
btrfs_super_root_dir(root->fs_info->disk_super),
&location, BTRFS_FT_DIR);
if (ret)
goto err;
btrfs_commit_transaction(trans, root, root->fs_info->disk_super);
ret = close_ctree(root, &super);
err:
return ret;
}
int mkfs(int fd, char *pathname, 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;
struct btrfs_inode_item *inode_item;
char *block;
int ret;
u32 itemoff;
u32 start_block = BTRFS_SUPER_INFO_OFFSET / blocksize;
btrfs_set_super_generation(&super, 1);
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, start_block + 4);
uuid_generate(super.fsid);
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_blocknr(&empty_leaf->header, start_block + 1);
btrfs_set_header_nritems(&empty_leaf->header, 2);
btrfs_set_header_generation(&empty_leaf->header, 0);
btrfs_set_header_owner(&empty_leaf->header, BTRFS_ROOT_TREE_OBJECTID);
memcpy(empty_leaf->header.fsid, super.fsid,
sizeof(empty_leaf->header.fsid));
/* create the items for the root tree */
inode_item = &root_item.inode;
memset(inode_item, 0, sizeof(*inode_item));
btrfs_set_inode_generation(inode_item, 1);
btrfs_set_inode_size(inode_item, 3);
btrfs_set_inode_nlink(inode_item, 1);
btrfs_set_inode_nblocks(inode_item, 1);
btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_dirid(&root_item, 0);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_disk_key_offset(&item.key, 0);
btrfs_set_disk_key_flags(&item.key, 0);
btrfs_set_item_size(&item, sizeof(root_item));
btrfs_set_disk_key_type(&item.key, BTRFS_ROOT_ITEM_KEY);
itemoff = __BTRFS_LEAF_DATA_SIZE(blocksize) - sizeof(root_item);
btrfs_set_root_blocknr(&root_item, start_block + 2);
btrfs_set_item_offset(&item, itemoff);
btrfs_set_disk_key_objectid(&item.key, BTRFS_EXTENT_TREE_OBJECTID);
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_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, BTRFS_ROOT_TREE_OBJECTID);
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);
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);
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);
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_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;
}
u64 device_size(int fd, struct stat *st)
{
u64 size;
if (S_ISREG(st->st_mode)) {
return st->st_size;
}
if (!S_ISBLK(st->st_mode)) {
return 0;
}
if (ioctl(fd, BLKGETSIZE64, &size) >= 0) {
return size;
}
return 0; }
int main(int ac, char **av)
{
char *file;
u64 block_count = 0;
int fd;
struct stat st;
int ret;
int i;
char *buf = malloc(4096);
char *realpath_name;
radix_tree_init();
if (ac >= 2) {
file = av[1];
if (ac == 3) {
block_count = atoi(av[2]);
if (!block_count) {
fprintf(stderr, "error finding block count\n");
exit(1);
}
}
} else {
fprintf(stderr, "usage: mkfs.btrfs file [block count]\n");
exit(1);
}
fd = open(file, O_RDWR);
if (fd < 0) {
fprintf(stderr, "unable to open %s\n", file);
exit(1);
}
ret = fstat(fd, &st);
if (ret < 0) {
fprintf(stderr, "unable to stat %s\n", file);
exit(1);
}
if (block_count == 0) {
block_count = device_size(fd, &st);
if (block_count == 0) {
fprintf(stderr, "unable to find %s size\n", file);
exit(1);
}
block_count /= 4096;
}
if (block_count < 256) {
fprintf(stderr, "device %s is too small\n", file);
exit(1);
}
memset(buf, 0, 4096);
for(i = 0; i < 64; i++) {
ret = write(fd, buf, 4096);
if (ret != 4096) {
fprintf(stderr, "unable to zero fill device\n");
exit(1);
}
}
realpath_name = realpath(file, NULL);
ret = mkfs(fd, realpath_name, block_count, 4096);
if (ret) {
fprintf(stderr, "error during mkfs %d\n", ret);
exit(1);
}
ret = make_root_dir(fd);
if (ret) {
fprintf(stderr, "failed to setup the root directory\n");
exit(1);
}
printf("fs created on %s blocksize %d blocks %llu\n",
file, 4096, (unsigned long long)block_count);
return 0;
}