/*
* 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.
*/
#ifndef __BTRFS__
#define __BTRFS__
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/workqueue.h>
#include "bit-radix.h"
struct btrfs_trans_handle;
struct btrfs_transaction;
extern struct kmem_cache *btrfs_trans_handle_cachep;
extern struct kmem_cache *btrfs_transaction_cachep;
extern struct kmem_cache *btrfs_bit_radix_cachep;
extern struct kmem_cache *btrfs_path_cachep;
#define BTRFS_MAGIC "_BtRfS_M"
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
#define BTRFS_FS_TREE_OBJECTID 3ULL
#define BTRFS_ROOT_TREE_DIR_OBJECTID 4ULL
#define BTRFS_FIRST_FREE_OBJECTID 5ULL
/*
* we can actually store much bigger names, but lets not confuse the rest
* of linux
*/
#define BTRFS_NAME_LEN 255
/* 32 bytes in various csum fields */
#define BTRFS_CSUM_SIZE 32
/* four bytes for CRC32 */
#define BTRFS_CRC32_SIZE 4
#define BTRFS_EMPTY_DIR_SIZE 6
#define BTRFS_FT_UNKNOWN 0
#define BTRFS_FT_REG_FILE 1
#define BTRFS_FT_DIR 2
#define BTRFS_FT_CHRDEV 3
#define BTRFS_FT_BLKDEV 4
#define BTRFS_FT_FIFO 5
#define BTRFS_FT_SOCK 6
#define BTRFS_FT_SYMLINK 7
#define BTRFS_FT_MAX 8
/*
* the key defines the order in the tree, and so it also defines (optimal)
* block layout. objectid corresonds to the inode number. The flags
* tells us things about the object, and is a kind of stream selector.
* so for a given inode, keys with flags of 1 might refer to the inode
* data, flags of 2 may point to file data in the btree and flags == 3
* may point to extents.
*
* offset is the starting byte offset for this key in the stream.
*
* btrfs_disk_key is in disk byte order. struct btrfs_key is always
* in cpu native order. Otherwise they are identical and their sizes
* should be the same (ie both packed)
*/
struct btrfs_disk_key {
__le64 objectid;
__le32 flags;
__le64 offset;
} __attribute__ ((__packed__));
struct btrfs_key {
u64 objectid;
u32 flags;
u64 offset;
} __attribute__ ((__packed__));
/*
* every tree block (leaf or node) starts with this header.
*/
struct btrfs_header {
u8 csum[BTRFS_CSUM_SIZE];
u8 fsid[16]; /* FS specific uuid */
__le64 blocknr; /* which block this node is supposed to live in */
__le64 generation;
__le64 owner;
__le16 nritems;
__le16 flags;
u8 level;
} __attribute__ ((__packed__));
#define BTRFS_MAX_LEVEL 8
#define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->blocksize - \
sizeof(struct btrfs_header)) / \
(sizeof(struct btrfs_disk_key) + sizeof(u64)))
#define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
#define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->blocksize))
#define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
sizeof(struct btrfs_item) - \
sizeof(struct btrfs_file_extent_item))
struct buffer_head;
/*
* the super block basically lists the main trees of the FS
* it currently lacks any block count etc etc
*/
struct btrfs_super_block {
u8 csum[BTRFS_CSUM_SIZE];
/* the first 3 fields must match struct btrfs_header */
u8 fsid[16]; /* FS specific uuid */
__le64 blocknr; /* this block number */
__le64 magic;
__le64 generation;
__le64 root;
__le64 total_blocks;
__le64 blocks_used;
__le64 root_dir_objectid;
__le32 blocksize;
} __attribute__ ((__packed__));
/*
* A leaf is full of items. offset and size tell us where to find
* the item in the leaf (relative to the start of the data area)
*/
struct btrfs_item {
struct btrfs_disk_key key;
__le32 offset;
__le16 size;
} __attribute__ ((__packed__));
/*
* leaves have an item area and a data area:
* [item0, item1....itemN] [free space] [dataN...data1, data0]
*
* The data is separate from the items to get the keys closer together
* during searches.
*/
struct btrfs_leaf {
struct btrfs_header header;
struct btrfs_item items[];
} __attribute__ ((__packed__));
/*
* all non-leaf blocks are nodes, they hold only keys and pointers to
* other blocks
*/
struct btrfs_key_ptr {
struct btrfs_disk_key key;
__le64 blockptr;
} __attribute__ ((__packed__));
struct btrfs_node {
struct btrfs_header header;
struct btrfs_key_ptr ptrs[];
} __attribute__ ((__packed__));
/*
* btrfs_paths remember the path taken from the root down to the leaf.
* level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
* to any other levels that are present.
*
* The slots array records the index of the item or block pointer
* used while walking the tree.
*/
struct btrfs_path {
struct buffer_head *nodes[BTRFS_MAX_LEVEL];
int slots[BTRFS_MAX_LEVEL];
int reada