/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _BTRFS_CTREE_H_
#define _BTRFS_CTREE_H_
#include <linux/btrfs.h>
#include <linux/types.h>
#include <stddef.h>
/* ASCII for _BHRfS_M, no terminating nul */
#define BTRFS_MAGIC 0x4D5F53665248425FULL
#define BTRFS_MAX_LEVEL 8
/*
* We can actually store much bigger names, but lets not confuse the rest of
* linux.
*/
#define BTRFS_NAME_LEN 255
/*
* Theoretical limit is larger, but we keep this down to a sane value. That
* should limit greatly the possibility of collisions on inode ref items.
*/
#define BTRFS_LINK_MAX 65535U
/*
* This header contains the structure definitions and constants used
* by file system objects that can be retrieved using
* the BTRFS_IOC_SEARCH_TREE ioctl. That means basically anything that
* is needed to describe a leaf node's key or item contents.
*/
/* holds pointers to all of the tree roots */
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
/* stores information about which extents are in use, and reference counts */
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
/*
* chunk tree stores translations from logical -> physical block numbering
* the super block points to the chunk tree
*/
#define BTRFS_CHUNK_TREE_OBJECTID 3ULL
/*
* stores information about which areas of a given device are in use.
* one per device. The tree of tree roots points to the device tree
*/
#define BTRFS_DEV_TREE_OBJECTID 4ULL
/* one per subvolume, storing files and directories */
#define BTRFS_FS_TREE_OBJECTID 5ULL
/* directory objectid inside the root tree */
#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
/* holds checksums of all the data extents */
#define BTRFS_CSUM_TREE_OBJECTID 7ULL
/* holds quota configuration and tracking */
#define BTRFS_QUOTA_TREE_OBJECTID 8ULL
/* for storing items that use the BTRFS_UUID_KEY* types */
#define BTRFS_UUID_TREE_OBJECTID 9ULL
/* tracks free space in block groups. */
#define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
/* Holds the block group items for extent tree v2. */
#define BTRFS_BLOCK_GROUP_TREE_OBJECTID 11ULL
/* Tracks RAID stripes in block groups. */
#define BTRFS_RAID_STRIPE_TREE_OBJECTID 12ULL
/* device stats in the device tree */
#define BTRFS_DEV_STATS_OBJECTID 0ULL
/* for storing balance parameters in the root tree */
#define BTRFS_BALANCE_OBJECTID -4ULL
/* orphan objectid for tracking unlinked/truncated files */
#define BTRFS_ORPHAN_OBJECTID -5ULL
/* does write ahead logging to speed up fsyncs */
#define BTRFS_TREE_LOG_OBJECTID -6ULL
#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
/* for space balancing */
#define BTRFS_TREE_RELOC_OBJECTID -8ULL
#define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
/*
* extent checksums all have this objectid
* this allows them to share the logging tree
* for fsyncs
*/
#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
/* For storing free space cache */
#define BTRFS_FREE_SPACE_OBJECTID -11ULL
/*
* The inode number assigned to the special inode for storing
* free ino cache
*/
#define BTRFS_FREE_INO_OBJECTID -12ULL
/* dummy objectid represents multiple objectids */
#define BTRFS_MULTIPLE_OBJECTIDS -255ULL
/*
* All files have objectids in this range.
*/
#define BTRFS_FIRST_FREE_OBJECTID 256ULL
#define BTRFS_LAST_FREE_OBJECTID -256ULL
#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
/*
* the device items go into the chunk tree. The key is in the form
* [ 1 BTRFS_DEV_ITEM_KEY device_id ]
*/
#define BTRFS_DEV_ITEMS_OBJECTID 1ULL
#define BTRFS_BTREE_INODE_OBJECTID 1
#define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
#define BTRFS_DEV_REPLACE_DEVID 0ULL
/*
* inode items have the data typically returned from stat and store other
* info about object characteristics. There is one for every file and dir in
* the FS
*/
#define BTRFS_INODE_ITEM_KEY 1
#define BTRFS_INODE_REF_KEY 12
#define BTRFS_INODE_EXTREF_KEY 13
#define BTRFS_XATTR_ITEM_KEY 24
/*
* fs verity items are stored under two different key types on disk.
* The descriptor items:
* [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ]
*
* At offset 0, we store a btrfs_verity_descriptor_item which tracks the size
* of the descriptor item and some extra data for encryption.
* Starting at offset 1, these hold the generic fs verity descriptor. The
* latter are opaque to btrfs, we just read and write them as a blob for the
* higher level verity code. The most common descriptor size is 256 bytes.
*
* The merkle tree items:
* [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ]
*
* These also start at offset 0, and correspond to the merkle tree bytes. When
* fsverity asks for page 0 of the merkle tree, we pull up one page starting at
* offset 0 for this key type. These are also opaque to btrfs, we're blindly
* storing whatever fsverity sends down.
*/
#define BTRFS_VERITY_DESC_ITEM_KEY 36
#define BTRFS_VERITY_MERKLE_ITEM_KEY 37
#define BTRFS_ORPHAN_ITEM_KEY 48
/* reserve 2-15 close to the inode for later flexibility */
/*
* dir items are the name -> inode pointers in a directory. There is one
* for every name in a directory. BTRFS_DIR_LOG_ITEM_KEY is no longer used
* but it's still defined here for documentation purposes and to help avoid
* having its numerical value reused in the future.
*/
#define BTRFS_DIR_LOG_ITEM_KEY 60
#define BTRFS_DIR_LOG_INDEX_KEY 72
#define BTRFS_DIR_ITEM_KEY 84
#define BTRFS_DIR_INDEX_KEY 96
/*
* extent data is for file data
*/
#define BTRFS_EXTENT_DATA_KEY 108
/*
* extent csums are stored in a separate tree and hold csums for
* an entire extent on disk.
*/
#define BTRFS_EXTENT_CSUM_KEY 128
/*
* root items point to tree roots. They are typically in the root
* tree used by the super block to find all the other trees
*/
#define BTRFS_ROOT_ITEM_KEY 132
/*
* root backrefs tie subvols and snapshots to the directory entries that
* reference them
*/
#define BTRFS_ROOT_BACKREF_KEY 144
/*
* root refs make a fast index for listing all of the snapshots and
* subvolumes referenced by a given root. They point directly to the
* directory item in the root that references the subvol
*/
#define BTRFS_ROOT_REF_KEY 156
/*
* extent items are in the extent map tree. These record which blocks
* are used, and how many references there are to each block
*/
#define BTRFS_EXTENT_ITEM_KEY 168
/*
* The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
* the length, so we save the level in key->offset instead of the length.
*/
#define BTRFS_METADATA_ITEM_KEY 169
/*
* Special __inline__ ref key which stores the id of the subvolume which originally
* created the extent. This subvolume owns the extent permanently from the
* perspective of simple quotas. Needed to know which subvolume to free quota
* usage from when the extent is deleted.
*
* Stored as an __inline__ ref rather to avoid wasting space on a separate item on
* top of the existing extent item. However, unlike the other __inline__ refs,
* there is one one owner ref per extent rather than one per extent.
*
* Because of this, it goes at the front of the list of __inline__ refs, and thus
* must have a lower type value than any other __inline__ ref type (to satisfy the
* disk format rule that __inline__ refs have non-decreasing type).
*/
#define BTRFS_EXTENT_OWNER_REF_KEY 172
#define BTRFS_TREE_BLOCK_REF_KEY 176
#define BTRFS_EXTENT_DATA_REF_KEY 178
/*
* Obsolete key. Defintion removed in 6.6, value may be reused in the future.
*
* #define BTRFS_EXTENT_REF_V0_KEY 180
*/
#define BTRFS_SHARED_BLOCK_REF_KEY 182
#define BTRFS_SHARED_DATA_REF_KEY 184
/*
* block groups give us hints into the extent allocation trees. Which
* blocks are free etc etc
*/
#define BTRFS_BLOCK_GROUP_ITEM_KEY 192
/*
* Every block group is represented in the free space tree by a free space info
* item, which stores some accounting information. It is keyed on
* (block_group_start, FREE_SPACE_INFO, block_group_length).
*/
#define BTRFS_FREE_SPACE_INFO_KEY 198
/*
* A free space extent tracks an extent of space that is free in a block group.
* It is keyed on (start, FREE_SPACE_EXTENT, length).
*/
#define BTRFS_FREE_SPACE_EXTENT_KEY 199
/*
* When a block group becomes very fragmented, we convert it to use bitmaps
* instead of extents. A free space bitmap is keyed on
* (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with
* (length / sectorsize) bits.
*/
#define BTRFS_FREE_SPACE_BITMAP_KEY 200
#define BTRFS_DEV_EXTENT_KEY 204
#define BTRFS_DEV_ITEM_KEY 216
#define BTRFS_CHUNK_ITEM_KEY 228
#define BTRFS_RAID_STRIPE_KEY 230
/*
* Records the overall state of the qgroups.
* There's only one instance of this key present,
* (0, BTRFS_QGROUP_STATUS_KEY, 0)
*/
#define BTRFS_QGROUP_STATUS_KEY 240
/*
* Records the currently used space of the qgroup.
* One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
*/
#define BTRFS_QGROUP_INFO_KEY 242
/*
* Contains the user configured limits for the qgroup.
* One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
*/
#define BTRFS_QGROUP_LIMIT_KEY 244
/*
* Records the child-parent relationship of qgroups. For
* each relation, 2 keys are present:
* (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
* (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
*/
#define BTRFS_QGROUP_RELATION_KEY 246
/*
* Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
*/
#define BTRFS_BALANCE_ITEM_KEY 248
/*
* The key type for tree items that are stored persistently, but do not need to
* exist for extended period of time. The items can exist in any tree.
*
* [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
*
* Existing items:
*
* - balance status item
* (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
*/
#define BTRFS_TEMPORARY_ITEM_KEY 248
/*
* Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY
*/
#define BTRFS_DEV_STATS_KEY 249
/*
* The key type for tree items that are stored persistently and usually exist
* for a long period, eg. filesystem lifetime. The item kinds can be status
* information, stats or preference values. The item can exist in any tree.
*
* [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
*
* Existing items:
*
* - device statistics, store IO stats in the device tree, one key for all
* stats
* (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
*/
#define BTRFS_PERSISTENT_ITEM_KEY 249
/*
* Persistently stores the device replace state in the device tree.
* The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
*/
#define BTRFS_DEV_REPLACE_KEY 250
/*
* Stores items that allow to quickly map UUIDs to something else.
* These items are part of the filesystem UUID tree.
* The key is built like this:
* (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
*/
#if BTRFS_UUID_SIZE != 16
#error "UUID items require BTRFS_UUID_SIZE == 16!"
#endif
#define BTRFS_UUID_KEY_SUBVOL 251 /* for UUIDs assigned to subvols */
#define BTRFS_UUID_KEY_RECEIVED_SUBVOL 252 /* for UUIDs assigned to
* received subvols */
/*
* string items are for debugging. They just store a short string of
* data in the FS
*/
#define BTRFS_STRING_ITEM_KEY 253
/* Maximum metadata block size (nodesize) */
#define BTRFS_MAX_METADATA_BLOCKSIZE 65536
/* 32 bytes in various csum fields */
#define BTRFS_CSUM_SIZE 32
/* csum types */
enum btrfs_csum_type {
BTRFS_CSUM_TYPE_CRC32 = 0,
BTRFS_CSUM_TYPE_XXHASH = 1,
BTRFS_CSUM_TYPE_SHA256 = 2,
BTRFS_CSUM_TYPE_BLAKE2 = 3,
};
/*
* flags definitions for directory entry item type
*
* Used by:
* struct btrfs_dir_item.type
*
* Values 0..7 must match common file type values in fs_types.h.
*/
#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_XATTR 8
#define BTRFS_FT_MAX 9
/* Directory contains encrypted data */
#define BTRFS_FT_ENCRYPTED 0x80
static __inline__ __u8 btrfs_dir_flags_to_ftype(__u8 flags)
{
return flags & ~BTRFS_FT_ENCRYPTED;
}
/*
* Inode flags
*/
#define BTRFS_INODE_NODATASUM (1U << 0)
#define BTRFS_INODE_NODATACOW (1U << 1)
#define BTRFS_INODE_READONLY (1U << 2)
#define BTRFS_INODE_NOCOMPRESS (1U << 3)
#define BTRFS_INODE_PREALLOC (1U << 4)
#define BTRFS_INODE_SYNC (1U << 5)
#define BTRFS_INODE_IMMUTABLE (1U << 6)
#define BTRFS_INODE_APPEND (1U << 7)
#define BTRFS_INODE_NODUMP (1U << 8)
#define BTRFS_INODE_NOATIME (1U << 9)
#define BTRFS_INODE_DIRSYNC (1U << 10)
#define BTRFS_INODE_COMPRESS (1U << 11)
#define BTRFS_INODE_ROOT_ITEM_INIT (1U << 31)
#define BTRFS_INODE_FLAG_MASK \
(BTRFS_INODE_NODATASUM | \
BTRFS_INODE_NODATACOW | \
BTRFS_INODE_READONLY | \
BTRFS_INODE_NOCOMPRESS | \
BTRFS_INODE_PREALLOC | \
BTRFS_INODE_SYNC | \
BTRFS_INODE_IMMUTABLE | \
BTRFS_INODE_APPEND | \
BTRFS_INODE_NODUMP | \
BTRFS_INODE_NOATIME | \
BTRFS_INODE_DIRSYNC | \
BTRFS_INODE_COMPRESS | \
BTRFS_INODE_ROOT_ITEM_INIT)
#define BTRFS_INODE_RO_VERITY (1U << 0)
#define BTRFS_INODE_RO_FLAG_MASK (BTRFS_INODE_RO_VERITY)
/*
* The key defines the order in the tree, and so it also defines (optimal)
* block layout.
*
* objectid corresponds to the inode number.
*
* type tells us things about the object, and is a kind of stream selector.
* so for a given inode, keys with type of 1 might refer to the inode data,
* type of 2 may point to file data in the btree and type == 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;
__u8 type;
__le64 offset;
} __attribute__ ((__packed__));
struct btrfs_key {
__u64 objectid;
__u8 type;
__u64 offset;
} __attribute__ ((__packed__));
/*
* Every tree block (leaf or node) starts with this header.
*/
struct btrfs_header {
/* These first four must match the super block */
__u8 csum[BTRFS_CSUM_SIZE];
/* FS specific uuid */
__u8 fsid[BTRFS_FSID_SIZE];
/* Which block this node is supposed to live in */
__le64 bytenr;
__le64 flags;
/* Allowed to be different from the super from here on down */
__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
__le64 generation;
__le64 owner;
__le32 nritems;
__u8 level;
} __attribute__ ((__packed__));
/*
* This is a very generous portion of the super block, giving us room to
* translate 14 chunks with 3 stripes each.
*/
#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
/*
* Just in case we somehow lose the roots and are not able to mount, we store
* an array of the roots from previous transactions in the super.
*/
#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 unused_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__));
/*
* 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;
__le32 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;
__le64 generation;
} __attribute__ ((__packed__));
struct btrfs_node {
struct btrfs_header header;
struct btrfs_key_ptr ptrs[];
} __attribute__ ((__packed__));
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 allow 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_stripe {
__le64 devid;
__le64 offset;
__u8 dev_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));
struct btrfs_chunk {
/* size of this chunk in bytes */
__le64 length;
/* objectid of the root referencing this chunk */
__le64 owner;
__le64 stripe_len;
__le64 type;
/* optimal io alignment for this chunk */
__le32 io_align;
/* optimal io width for this chunk */
__le32 io_width;
/* minimal io size for this chunk */
__le32 sector_size;
/* 2^16 stripes is quite a lot, a second limit is the size of a single
* item in the btree
*/
__le16 num_stripes;
/* sub stripes only matter for raid10 */
__le16 sub_stripes;
struct btrfs_stripe stripe;
/* additional stripes go here */
} __attribute__ ((__packed__));
/*
* The super block basically lists the main trees of the FS.
*/
struct btrfs_super_block {
/* The first 4 fields must match struct btrfs_header */
__u8 csum[BTRFS_CSUM_SIZE];
/* FS specific UUID, visible to user */
__u8 fsid[BTRFS_FSID_SIZE];
/* This block number */
__le64 bytenr;
__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 member has never been utilized since the very beginning, thus
* it's always 0 regardless of kernel version. We always use
* generation + 1 to read log tree root. So here we mark it deprecated.
*/
__le64 __unused_log_root_transid;
__le64 total_bytes;
__le64 bytes_used;
__le64 root_dir_objectid;
__le64 num_devices;
__le32 sectorsize;
__le32 nodesize;
__le32 __unused_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;
/* The UUID written into btree blocks */
__u8 metadata_uuid[BTRFS_FSID_SIZE];
__u64 nr_global_roots;
/* Future expansion */
__le64 reserved[27];
__u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
/* Padded to 4096 bytes */
__u8 padding[565];
} __attribute__ ((__packed__));
#define BTRFS_FREE_SPACE_EXTENT 1
#define BTRFS_FREE_SPACE_BITMAP 2
struct btrfs_free_space_entry {
__le64 offset;
__le64 bytes;
__u8 type;
} __attribute__ ((__packed__));
struct btrfs_free_space_header {
struct btrfs_disk_key location;
__le64 generation;
__le64 num_entries;
__le64 num_bitmaps;
} __attribute__ ((__packed__));
struct btrfs_raid_stride {
/* The id of device this raid extent lives on. */
__le64 devid;
/* The physical location on disk. */
__le64 physical;
} __attribute__ ((__packed__));
/* The stripe_extent::encoding, 1:1 mapping of enum btrfs_raid_types. */
#define BTRFS_STRIPE_RAID0 1
#define BTRFS_STRIPE_RAID1 2
#define BTRFS_STRIPE_DUP 3
#define BTRFS_STRIPE_RAID10 4
#define BTRFS_STRIPE_RAID5 5
#define BTRFS_STRIPE_RAID6 6
#define BTRFS_STRIPE_RAID1C3 7
#define BTRFS_STRIPE_RAID1C4 8
struct btrfs_stripe_extent {
__u8 encoding;
__u8 reserved[7];
/* An array of raid strides this stripe is composed of. */
struct btrfs_raid_stride strides[];
} __attribute__ ((__packed__));
#define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0)
#define BTRFS_HEADER_FLAG_RELOC (1ULL << 1)
/* Super block flags */
/* Errors detected */
#define BTRFS_SUPER_FLAG_ERROR (1ULL << 2)
#define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32)
#define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33)
#define BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34)
#define BTRFS_SUPER_FLAG_CHANGING_FSID (1ULL << 35)
#define BTRFS_SUPER_FLAG_CHANGING_FSID_V2 (1ULL << 36)
/*
* items in the extent btree are used to record the objectid of the
* owner of the block and the number of references
*/
struct btrfs_extent_item {
__le64 refs;
__le64 generation;
__le64 flags;
} __attribute__ ((__packed__));
struct btrfs_extent_item_v0 {
__le32 refs;
} __attribute__ ((__packed__));
#define BTRFS_EXTENT_FLAG_DATA (1ULL << 0)
#define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1)
/* following flags only apply to tree blocks */
/* use full backrefs for extent pointers in the block */
#define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8)
#define BTRFS_BACKREF_REV_MAX 256
#define BTRFS_BACKREF_REV_SHIFT 56
#define BTRFS_BACKREF_REV_MASK (((u64)BTRFS_BACKREF_REV_MAX - 1) << \
BTRFS_BACKREF_REV_SHIFT)
#define BTRFS_OLD_BACKREF_REV 0
#define BTRFS_MIXED_BACKREF_REV 1
/*
* this flag is only used internally by scrub and may be changed at any time
* it is only declared here to avoid collisions
*/
#define BTRFS_EXTENT_FLAG_SUPER (1ULL << 48)
struct btrfs_tree_block_info {
struct btrfs_disk_key key;
__u8 level;
} __attribute__ ((__packed__));
struct btrfs_extent_data_ref {
__le64 root;
__le64 objectid;
__le64 offset;
__le32 count;
} __attribute__ ((__packed__));
struct btrfs_shared_data_ref {
__le32 count;
} __attribute__ ((__packed__));
struct btrfs_extent_owner_ref {
__le64 root_id;
} __attribute__ ((__packed__));
struct btrfs_extent_inline_ref {
__u8 type;
__le64 offset;
} __attribute__ ((__packed__));
/* dev extents record free space on individual devices. The owner
* field points back to the chunk allocation mapping tree that allocated
* the extent. The chunk tree uuid field is a way to double check the owner
*/
struct btrfs_dev_extent {
__le64 chunk_tree;
__le64 chunk_objectid;
__le64 chunk_offset;
__le64 length;
__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));
struct btrfs_inode_ref {
__le64 index;
__le16 name_len;
/* name goes here */
} __attribute__ ((__packed__));
struct btrfs_inode_extref {
__le64 parent_objectid;
__le64 index;
__le16 name_len;
__u8 name[];
/* name goes here */
} __attribute__ ((__packed__));
struct btrfs_timespec {
__le64 sec;
__le32 nsec;
} __attribute__ ((__packed__));
struct btrfs_inode_item {
/* nfs style generation number */
__le64 generation;
/* transid that last touched this inode */
__le64 transid;
__le64 size;
__le64 nbytes;
__le64 block_group;
__le32 nlink;
__le32 uid;
__le32 gid;
__le32 mode;
__le64 rdev;
__le64 flags;
/* modification sequence number for NFS */
__le64 sequence;
/*
* a little future expansion, for more than this we can
* just grow the inode item and version it
*/
__le64 reserved[4];
struct btrfs_timespec atime;
struct btrfs_timespec ctime;
struct btrfs_timespec mtime;
struct btrfs_timespec otime;
} __attribute__ ((__packed__));
struct btrfs_dir_log_item {
__le64 end;
} __attribute__ ((__packed__));
struct btrfs_dir_item {
struct btrfs_disk_key location;
__le64 transid;
__le16 data_len;
__le16 name_len;
__u8 type;
} __attribute__ ((__packed__));
#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
/*
* Internal in-memory flag that a subvolume has been marked for deletion but
* still visible as a directory
*/
#define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48)
struct btrfs_root_item {
struct btrfs_inode_item inode;
__le64 generation;
__le64 root_dirid;
__le64 bytenr;
__le64 byte_limit;
__le64 bytes_used;
__le64 last_snapshot;
__le64 flags;
__le32 refs;
struct btrfs_disk_key drop_progress;
__u8 drop_level;
__u8 level;
/*
* The following fields appear after subvol_uuids+subvol_times
* were introduced.
*/
/*
* This generation number is used to test if the new fields are valid
* and up to date while reading the root item. Every time the root item
* is written out, the "generation" field is copied into this field. If
* anyone ever mounted the fs with an older kernel, we will have
* mismatching generation values here and thus must invalidate the
* new fields. See btrfs_update_root and btrfs_find_last_root for
* details.
* the offset of generation_v2 is also used as the start for the memset
* when invalidating the fields.
*/
__le64 generation_v2;
__u8 uuid[BTRFS_UUID_SIZE];
__u8 parent_uuid[BTRFS_UUID_SIZE];
__u8 received_uuid[BTRFS_UUID_SIZE];
__le64 ctransid; /* updated when an inode changes */
__le64 otransid; /* trans when created */
__le64 stransid; /* trans when sent. non-zero for received subvol */
__le64 rtransid; /* trans when received. non-zero for received subvol */
struct btrfs_timespec ctime;
struct btrfs_timespec otime;
struct btrfs_timespec stime;
struct btrfs_timespec rtime;
__le64 reserved[8]; /* for future */
} __attribute__ ((__packed__));
/*
* Btrfs root item used to be smaller than current size. The old format ends
* at where member generation_v2 is.
*/
static __inline__ __u32 btrfs_legacy_root_item_size(void)
{
return offsetof(struct btrfs_root_item, generation_v2);
}
/*
* this is used for both forward and backward root refs
*/
struct btrfs_root_ref {
__le64 dirid;
__le64 sequence;
__le16 name_len;
} __attribute__ ((__packed__));
struct btrfs_disk_balance_args {
/*
* profiles to operate on, single is denoted by
* BTRFS_AVAIL_ALLOC_BIT_SINGLE
*/
__le64 profiles;
/*
* usage filter
* BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N'
* BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
*/
union {
__le64 usage;
struct {
__le32 usage_min;
__le32 usage_max;
};
};
/* devid filter */
__le64 devid;
/* devid subset filter [pstart..pend) */
__le64 pstart;
__le64 pend;
/* btrfs virtual address space subset filter [vstart..vend) */
__le64 vstart;
__le64 vend;
/*
* profile to convert to, single is denoted by
* BTRFS_AVAIL_ALLOC_BIT_SINGLE
*/
__le64 target;
/* BTRFS_BALANCE_ARGS_* */
__le64 flags;
/*
* BTRFS_BALANCE_ARGS_LIMIT with value 'limit'
* BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum
* and maximum
*/
union {
__le64 limit;
struct {
__le32 limit_min;
__le32 limit_max;
};
};
/*
* Process chunks that cross stripes_min..stripes_max devices,
* BTRFS_BALANCE_ARGS_STRIPES_RANGE
*/
__le32 stripes_min;
__le32 stripes_max;
__le64 unused[6];
} __attribute__ ((__packed__));
/*
* store balance parameters to disk so that balance can be properly
* resumed after crash or unmount
*/
struct btrfs_balance_item {
/* BTRFS_BALANCE_* */
__le64 flags;
struct btrfs_disk_balance_args data;
struct btrfs_disk_balance_args meta;
struct btrfs_disk_balance_args sys;
__le64 unused[4];
} __attribute__ ((__packed__));
enum {
BTRFS_FILE_EXTENT_INLINE = 0,
BTRFS_FILE_EXTENT_REG = 1,
BTRFS_FILE_EXTENT_PREALLOC = 2,
BTRFS_NR_FILE_EXTENT_TYPES = 3,
};
struct btrfs_file_extent_item {
/*
* transaction id that created this extent
*/
__le64 generation;
/*
* max number of bytes to hold this extent in ram
* when we split a compressed extent we can't know how big
* each of the resulting pieces will be. So, this is
* an upper limit on the size of the extent in ram instead of
* an exact limit.
*/
__le64 ram_bytes;
/*
* 32 bits for the various ways we might encode the data,
* including compression and encryption. If any of these
* are set to something a given disk format doesn't understand
* it is treated like an incompat flag for reading and writing,
* but not for stat.
*/
__u8 compression;
__u8 encryption;
__le16 other_encoding; /* spare for later use */
/* are we __inline__ data or a real extent? */
__u8 type;
/*
* disk space consumed by the extent, checksum blocks are included
* in these numbers
*
* At this offset in the structure, the __inline__ extent data start.
*/
__le64 disk_bytenr;
__le64 disk_num_bytes;
/*
* the logical offset in file blocks (no csums)
* this extent record is for. This allows a file extent to point
* into the middle of an existing extent on disk, sharing it
* between two snapshots (useful if some bytes in the middle of the
* extent have changed
*/
__le64 offset;
/*
* the logical number of file blocks (no csums included). This
* always reflects the size uncompressed and without encoding.
*/
__le64 num_bytes;
} __attribute__ ((__packed__));
struct btrfs_csum_item {
__u8 csum;
} __attribute__ ((__packed__));
struct btrfs_dev_stats_item {
/*
* grow this item struct at the end for future enhancements and keep
* the existing values unchanged
*/
__le64 values[BTRFS_DEV_STAT_VALUES_MAX];
} __attribute__ ((__packed__));
#define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS 0
#define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID 1
struct btrfs_dev_replace_item {
/*
* grow this item struct at the end for future enhancements and keep
* the existing values unchanged
*/
__le64 src_devid;
__le64 cursor_left;
__le64 cursor_right;
__le64 cont_reading_from_srcdev_mode;
__le64 replace_state;
__le64 time_started;
__le64 time_stopped;
__le64 num_write_errors;
__le64 num_uncorrectable_read_errors;
} __attribute__ ((__packed__));
/* different types of block groups (and chunks) */
#define BTRFS_BLOCK_GROUP_DATA (1ULL << 0)
#define BTRFS_BLOCK_GROUP_SYSTEM (1ULL << 1)
#define BTRFS_BLOCK_GROUP_METADATA (1ULL << 2)
#define BTRFS_BLOCK_GROUP_RAID0 (1ULL << 3)
#define BTRFS_BLOCK_GROUP_RAID1 (1ULL << 4)
#define BTRFS_BLOCK_GROUP_DUP (1ULL << 5)
#define BTRFS_BLOCK_GROUP_RAID10 (1ULL << 6)
#define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7)
#define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8)
#define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9)
#define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10)
#define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
BTRFS_SPACE_INFO_GLOBAL_RSV)
#define BTRFS_BLOCK_GROUP_TYPE_MASK (BTRFS_BLOCK_GROUP_DATA | \
BTRFS_BLOCK_GROUP_SYSTEM | \
BTRFS_BLOCK_GROUP_METADATA)
#define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \
BTRFS_BLOCK_GROUP_RAID1 | \
BTRFS_BLOCK_GROUP_RAID1C3 | \
BTRFS_BLOCK_GROUP_RAID1C4 | \
BTRFS_BLOCK_GROUP_RAID5 | \
BTRFS_BLOCK_GROUP_RAID6 | \
BTRFS_BLOCK_GROUP_DUP | \
BTRFS_BLOCK_GROUP_RAID10)
#define BTRFS_BLOCK_GROUP_RAID56_MASK (BTRFS_BLOCK_GROUP_RAID5 | \
BTRFS_BLOCK_GROUP_RAID6)
#define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \
BTRFS_BLOCK_GROUP_RAID1C3 | \
BTRFS_BLOCK_GROUP_RAID1C4)
/*
* We need a bit for restriper to be able to tell when chunks of type
* SINGLE are available. This "extended" profile format is used in
* fs_info->avail_*_alloc_bits (in-memory) and balance item fields
* (on-disk). The corresponding on-disk bit in chunk.type is reserved
* to avoid remappings between two formats in future.
*/
#define BTRFS_AVAIL_ALLOC_BIT_SINGLE (1ULL << 48)
/*
* A fake block group type that is used to communicate global block reserve
* size to userspace via the SPACE_INFO ioctl.
*/
#define BTRFS_SPACE_INFO_GLOBAL_RSV (1ULL << 49)
#define BTRFS_EXTENDED_PROFILE_MASK (BTRFS_BLOCK_GROUP_PROFILE_MASK | \
BTRFS_AVAIL_ALLOC_BIT_SINGLE)
static __inline__ __u64 chunk_to_extended(__u64 flags)
{
if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0)
flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE;
return flags;
}
static __inline__ __u64 extended_to_chunk(__u64 flags)
{
return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
}
struct btrfs_block_group_item {
__le64 used;
__le64 chunk_objectid;
__le64 flags;
} __attribute__ ((__packed__));
struct btrfs_free_space_info {
__le32 extent_count;
__le32 flags;
} __attribute__ ((__packed__));
#define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0)
#define BTRFS_QGROUP_LEVEL_SHIFT 48
static __inline__ __u16 btrfs_qgroup_level(__u64 qgroupid)
{
return (__u16)(qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT);
}
/*
* is subvolume quota turned on?
*/
#define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0)
/*
* RESCAN is set during the initialization phase
*/
#define BTRFS_QGROUP_STATUS_FLAG_RESCAN (1ULL << 1)
/*
* Some qgroup entries are known to be out of date,
* either because the configuration has changed in a way that
* makes a rescan necessary, or because the fs has been mounted
* with a non-qgroup-aware version.
* Turning qouta off and on again makes it inconsistent, too.
*/
#define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2)
/*
* Whether or not this filesystem is using simple quotas. Not exactly the
* incompat bit, because we support using simple quotas, disabling it, then
* going back to full qgroup quotas.
*/
#define BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE (1ULL << 3)
#define BTRFS_QGROUP_STATUS_FLAGS_MASK (BTRFS_QGROUP_STATUS_FLAG_ON | \
BTRFS_QGROUP_STATUS_FLAG_RESCAN | \
BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT | \
BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE)
#define BTRFS_QGROUP_STATUS_VERSION 1
struct btrfs_qgroup_status_item {
__le64 version;
/*
* the generation is updated during every commit. As older
* versions of btrfs are not aware of qgroups, it will be
* possible to detect inconsistencies by checking the
* generation on mount time
*/
__le64 generation;
/* flag definitions see above */
__le64 flags;
/*
* only used during scanning to record the progress
* of the scan. It contains a logical address
*/
__le64 rescan;
/*
* The generation when quotas were last enabled. Used by simple quotas to
* avoid decrementing when freeing an extent that was written before
* enable.
*
* Set only if flags contain BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE.
*/
__le64 enable_gen;
} __attribute__ ((__packed__));
struct btrfs_qgroup_info_item {
__le64 generation;
__le64 rfer;
__le64 rfer_cmpr;
__le64 excl;
__le64 excl_cmpr;
} __attribute__ ((__packed__));
struct btrfs_qgroup_limit_item {
/*
* only updated when any of the other values change
*/
__le64 flags;
__le64 max_rfer;
__le64 max_excl;
__le64 rsv_rfer;
__le64 rsv_excl;
} __attribute__ ((__packed__));
struct btrfs_verity_descriptor_item {
/* Size of the verity descriptor in bytes */
__le64 size;
/*
* When we implement support for fscrypt, we will need to encrypt the
* Merkle tree for encrypted verity files. These 128 bits are for the
* eventual storage of an fscrypt initialization vector.
*/
__le64 reserved[2];
__u8 encryption;
} __attribute__ ((__packed__));
#endif /* _BTRFS_CTREE_H_ */
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