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btrfs-progs
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btrfs-progs/utils.c

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/*
* 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 600
#define __USE_XOPEN2K
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <uuid/uuid.h>
#include <fcntl.h>
#include <unistd.h>
#include "kerncompat.h"
#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "crc32c.h"
#include "utils.h"
static u64 reference_root_table[4] = {
[1] = BTRFS_ROOT_TREE_OBJECTID,
[2] = BTRFS_EXTENT_TREE_OBJECTID,
[3] = BTRFS_FS_TREE_OBJECTID,
};
int make_btrfs(int fd, u64 blocks[4], u64 num_bytes, u32 nodesize,
u32 leafsize, u32 sectorsize, u32 stripesize)
{
struct btrfs_super_block super;
struct extent_buffer *buf;
struct btrfs_root_item root_item;
struct btrfs_disk_key disk_key;
struct btrfs_extent_ref *extent_ref;
struct btrfs_extent_item *extent_item;
struct btrfs_inode_item *inode_item;
int i;
int ret;
u32 itemoff;
u32 nritems = 0;
u64 hash;
u64 first_free;
u64 ref_gen;
u64 ref_root;
first_free = BTRFS_SUPER_INFO_OFFSET + sectorsize * 2 - 1;
first_free &= ~((u64)sectorsize - 1);
num_bytes = (num_bytes / sectorsize) * sectorsize;
uuid_generate(super.fsid);
btrfs_set_super_bytenr(&super, blocks[0]);
strncpy((char *)&super.magic, BTRFS_MAGIC, sizeof(super.magic));
btrfs_set_super_generation(&super, 1);
btrfs_set_super_root(&super, blocks[1]);
btrfs_set_super_total_bytes(&super, num_bytes);
btrfs_set_super_bytes_used(&super, first_free + 3 * leafsize);
btrfs_set_super_root_dir(&super, 0);
btrfs_set_super_sectorsize(&super, sectorsize);
btrfs_set_super_leafsize(&super, leafsize);
btrfs_set_super_nodesize(&super, nodesize);
btrfs_set_super_stripesize(&super, stripesize);
btrfs_set_super_root_level(&super, 0);
buf = malloc(sizeof(*buf) + max(sectorsize, leafsize));
BUG_ON(sizeof(super) > sectorsize);
memset(buf->data, 0, sectorsize);
memcpy(buf->data, &super, sizeof(super));
ret = pwrite(fd, buf->data, sectorsize, blocks[0]);
BUG_ON(ret != sectorsize);
/* create the tree of root objects */
memset(buf->data, 0, leafsize);
btrfs_set_header_bytenr(buf, blocks[1]);
btrfs_set_header_nritems(buf, 2);
btrfs_set_header_generation(buf, 1);
btrfs_set_header_owner(buf, BTRFS_ROOT_TREE_OBJECTID);
write_extent_buffer(buf, super.fsid, (unsigned long)
btrfs_header_fsid(buf), BTRFS_FSID_SIZE);
/* create the items for the root tree */
memset(&root_item, 0, sizeof(root_item));
inode_item = &root_item.inode;
btrfs_set_stack_inode_generation(inode_item, 1);
btrfs_set_stack_inode_size(inode_item, 3);
btrfs_set_stack_inode_nlink(inode_item, 1);
btrfs_set_stack_inode_nblocks(inode_item, 1);
btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, leafsize);
memset(&disk_key, 0, sizeof(disk_key));
btrfs_set_disk_key_type(&disk_key, BTRFS_ROOT_ITEM_KEY);
btrfs_set_disk_key_offset(&disk_key, 0);
itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, blocks[2]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_EXTENT_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, 0);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, 0), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, 0), sizeof(root_item));
write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf, 0),
sizeof(root_item));
itemoff = itemoff - sizeof(root_item);
btrfs_set_root_bytenr(&root_item, blocks[3]);
btrfs_set_disk_key_objectid(&disk_key, BTRFS_FS_TREE_OBJECTID);
btrfs_set_item_key(buf, &disk_key, 1);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, 1), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, 1), sizeof(root_item));
write_extent_buffer(buf, &root_item, btrfs_item_ptr_offset(buf, 1),
sizeof(root_item));
ret = pwrite(fd, buf->data, leafsize, blocks[1]);
BUG_ON(ret != leafsize);
/* create the items for the extent tree */
itemoff = __BTRFS_LEAF_DATA_SIZE(leafsize) -
sizeof(struct btrfs_extent_item);
btrfs_set_disk_key_objectid(&disk_key, 0);
btrfs_set_disk_key_offset(&disk_key, first_free);
btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems), itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(struct btrfs_extent_item));
extent_item = btrfs_item_ptr(buf, nritems, struct btrfs_extent_item);
btrfs_set_extent_refs(buf, extent_item, 1);
nritems++;
for (i = 1; i < 4; i++) {
BUG_ON(blocks[i] < first_free);
BUG_ON(blocks[i] < blocks[i - 1]);
/* create extent item */
itemoff = itemoff - sizeof(struct btrfs_extent_item);
btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
btrfs_set_disk_key_offset(&disk_key, leafsize);
btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_ITEM_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(struct btrfs_extent_item));
extent_item = btrfs_item_ptr(buf, nritems,
struct btrfs_extent_item);
btrfs_set_extent_refs(buf, extent_item, 1);
nritems++;
/* create extent ref */
ref_root = reference_root_table[i];
if (ref_root == BTRFS_FS_TREE_OBJECTID)
ref_gen = 1;
else
ref_gen = 0;
hash = btrfs_hash_extent_ref(ref_root, ref_gen, 0, 0);
itemoff = itemoff - sizeof(struct btrfs_extent_ref);
btrfs_set_disk_key_objectid(&disk_key, blocks[i]);
btrfs_set_disk_key_offset(&disk_key, hash);
btrfs_set_disk_key_type(&disk_key, BTRFS_EXTENT_REF_KEY);
btrfs_set_item_key(buf, &disk_key, nritems);
btrfs_set_item_offset(buf, btrfs_item_nr(buf, nritems),
itemoff);
btrfs_set_item_size(buf, btrfs_item_nr(buf, nritems),
sizeof(struct btrfs_extent_ref));
extent_ref = btrfs_item_ptr(buf, nritems,
struct btrfs_extent_ref);
btrfs_set_ref_root(buf, extent_ref, ref_root);
btrfs_set_ref_generation(buf, extent_ref, ref_gen);
btrfs_set_ref_objectid(buf, extent_ref, 0);
btrfs_set_ref_offset(buf, extent_ref, 0);
nritems++;
}
btrfs_set_header_bytenr(buf, blocks[2]);
btrfs_set_header_owner(buf, BTRFS_EXTENT_TREE_OBJECTID);
btrfs_set_header_nritems(buf, nritems);
ret = pwrite(fd, buf->data, leafsize, blocks[2]);
BUG_ON(ret != leafsize);
/* finally create the FS root */
btrfs_set_header_bytenr(buf, blocks[3]);
btrfs_set_header_owner(buf, BTRFS_FS_TREE_OBJECTID);
btrfs_set_header_nritems(buf, 0);
ret = pwrite(fd, buf->data, leafsize, blocks[3]);
BUG_ON(ret != leafsize);
free(buf);
return 0;
}
int btrfs_make_root_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid)
{
int ret;
struct btrfs_inode_item inode_item;
memset(&inode_item, 0, sizeof(inode_item));
btrfs_set_stack_inode_generation(&inode_item, trans->transid);
btrfs_set_stack_inode_size(&inode_item, 0);
btrfs_set_stack_inode_nlink(&inode_item, 1);
btrfs_set_stack_inode_nblocks(&inode_item, 1);
btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0555);
if (root->fs_info->tree_root == root)
btrfs_set_super_root_dir(&root->fs_info->super_copy, objectid);
ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
if (ret)
goto error;
ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid);
if (ret)
goto error;
btrfs_set_root_dirid(&root->root_item, objectid);
ret = 0;
error:
return ret;
}
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