/*
* gm_btrfs.h -- gpart Btrfs volume guessing module header
*
* gpart (c) 1999-2001 Michail Brzitwa <mb@ichabod.han.de>
* Guess PC-type hard disk partitions.
*
* gpart is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2, or (at your
* option) any later version.
*
* Created: 20.11.2015 <mwilck@arcor.de>
* Modified:
*
*/
#ifndef _GM_BTRFS_H
#define _GM_BTRFS_H
/*
* structs & defines gathered from btrfs-progs
*/
#if !defined(__FreeBSD__)
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
typedef unsigned int uint32_t;
#endif
typedef uint64_t __le64;
typedef uint32_t __le32;
typedef uint16_t __le16;
typedef uint8_t u8;
#define BTRFS_SUPER_INFO_OFFSET (64 * 1024)
#define BTRFS_SUPER_INFO_SIZE 4096
#define btrfs_sb_offset(i) ((i) ? ((16*1024) << (BTRFS_SUPER_MIRROR_SHIFT * (i))) : BTRFS_SUPER_INFO_SIZE)
#define BTRFS_SUPER_MIRROR_SHIFT 12
#define BTRFS_CSUM_SIZE 32
#define BTRFS_FSID_SIZE 16
#define BTRFS_UUID_SIZE 16
#define BTRFS_MAGIC 0x4D5F53665248425FULL
#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
#define BTRFS_LABEL_SIZE 256
#define BTRFS_NUM_BACKUP_ROOTS 4
struct btrfs_root_backup {
__le64 tree_root;
__le64 tree_root_gen;
__le64 chunk_root;
__le64 chunk_root_gen;
__le64 extent_root;
__le64 extent_root_gen;
__le64 fs_root;
__le64 fs_root_gen;
__le64 dev_root;
__le64 dev_root_gen;
__le64 csum_root;
__le64 csum_root_gen;
__le64 total_bytes;
__le64 bytes_used;
__le64 num_devices;
/* future */
__le64 unsed_64[4];
u8 tree_root_level;
u8 chunk_root_level;
u8 extent_root_level;
u8 fs_root_level;
u8 dev_root_level;
u8 csum_root_level;
/* future and to align */
u8 unused_8[10];
} __attribute__ ((__packed__));
#define BTRFS_UUID_SIZE 16
struct btrfs_dev_item {
/* the internal btrfs device id */
__le64 devid;
/* size of the device */
__le64 total_bytes;
/* bytes used */
__le64 bytes_used;
/* optimal io alignment for this device */
__le32 io_align;
/* optimal io width for this device */
__le32 io_width;
/* minimal io size for this device */
__le32 sector_size;
/* type and info about this device */
__le64 type;
/* expected generation for this device */
__le64 generation;
/*
* starting byte of this partition on the device,
* to allowr for stripe alignment in the future
*/
__le64 start_offset;
/* grouping information for allocation decisions */
__le32 dev_group;
/* seek speed 0-100 where 100 is fastest */
u8 seek_speed;
/* bandwidth 0-100 where 100 is fastest */
u8 bandwidth;
/* btrfs generated uuid for this device */
u8 uuid[BTRFS_UUID_SIZE];
/* uuid of FS who owns this device */
u8 fsid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));
struct btrfs_super_block {
u8 csum[BTRFS_CSUM_SIZE];
/* the first 3 fields must match struct btrfs_header */
u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
__le64 bytenr; /* this block number */
__le64 flags;
/* allowed to be different from the btrfs_header from here own down */
__le64 magic;
__le64 generation;
__le64 root;
__le64 chunk_root;
__le64 log_root;
/* this will help find the new super based on the log root */
__le64 log_root_transid;
__le64 total_bytes;
__le64 bytes_used;
__le64 root_dir_objectid;
__le64 num_devices;
__le32 sectorsize;
__le32 nodesize;
__le32 leafsize;
__le32 stripesize;
__le32 sys_chunk_array_size;
__le64 chunk_root_generation;
__le64 compat_flags;
__le64 compat_ro_flags;
__le64 incompat_flags;
__le16 csum_type;
u8 root_level;
u8 chunk_root_level;
u8 log_root_level;
struct btrfs_dev_item dev_item;
char label[BTRFS_LABEL_SIZE];
__le64 cache_generation;
__le64 uuid_tree_generation;
/* future expansion */
__le64 reserved[30];
u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
} __attribute__ ((__packed__));
#endif /* _GM_BTRFS_H */