linux-stable/include/uapi/linux/btrfs_tree.h
Boris Burkov d9a620f77e btrfs: new inline ref storing owning subvol of data extents
In order to implement simple quota groups, we need to be able to
associate a data extent with the subvolume that created it. Once you
account for reflink, this information cannot be recovered without
explicitly storing it. Options for storing it are:

- a new key/item
- a new extent inline ref item

The former is backwards compatible, but wastes space, the latter is
incompat, but is efficient in space and reuses the existing inline ref
machinery, while only abusing it a tiny amount -- specifically, the new
item is not a ref, per-se.

Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2023-10-12 16:44:11 +02:00

1313 lines
34 KiB
C

/* 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>
#ifdef __KERNEL__
#include <linux/stddef.h>
#else
#include <stddef.h>
#endif
/* 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
#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
/*
* 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.
*/
#define BTRFS_EXTENT_OWNER_REF_KEY 188
/*
* 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;
} __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_ */