+++ /dev/null
-/* SPDX-License-Identifier: GPL-2.0+ */
-/*
- * From linux/include/uapi/linux/btrfs_tree.h
- */
-
-#ifndef __BTRFS_BTRFS_TREE_H__
-#define __BTRFS_BTRFS_TREE_H__
-
-#include <common.h>
-
-#define BTRFS_VOL_NAME_MAX 255
-#define BTRFS_NAME_MAX 255
-#define BTRFS_LABEL_SIZE 256
-#define BTRFS_FSID_SIZE 16
-#define BTRFS_UUID_SIZE 16
-
-/*
- * 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
-
-/* 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
-
-/* orhpan 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
-#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.
- */
-#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
-
-#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
-
-/*
- * 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
-
-/*
- * Persistantly 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
-
-
-
-/* 32 bytes in various csum fields */
-#define BTRFS_CSUM_SIZE 32
-
-/* csum types */
-#define BTRFS_CSUM_TYPE_CRC32 0
-
-/*
- * flags definitions for directory entry item type
- *
- * Used by:
- * struct btrfs_dir_item.type
- */
-#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
-
-/*
- * 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.
- */
-
-struct btrfs_key {
- __u64 objectid;
- __u8 type;
- __u64 offset;
-} __attribute__ ((__packed__));
-
-struct btrfs_dev_item {
- /* the internal btrfs device id */
- __u64 devid;
-
- /* size of the device */
- __u64 total_bytes;
-
- /* bytes used */
- __u64 bytes_used;
-
- /* optimal io alignment for this device */
- __u32 io_align;
-
- /* optimal io width for this device */
- __u32 io_width;
-
- /* minimal io size for this device */
- __u32 sector_size;
-
- /* type and info about this device */
- __u64 type;
-
- /* expected generation for this device */
- __u64 generation;
-
- /*
- * starting byte of this partition on the device,
- * to allow for stripe alignment in the future
- */
- __u64 start_offset;
-
- /* grouping information for allocation decisions */
- __u32 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 {
- __u64 devid;
- __u64 offset;
- __u8 dev_uuid[BTRFS_UUID_SIZE];
-} __attribute__ ((__packed__));
-
-struct btrfs_chunk {
- /* size of this chunk in bytes */
- __u64 length;
-
- /* objectid of the root referencing this chunk */
- __u64 owner;
-
- __u64 stripe_len;
- __u64 type;
-
- /* optimal io alignment for this chunk */
- __u32 io_align;
-
- /* optimal io width for this chunk */
- __u32 io_width;
-
- /* minimal io size for this chunk */
- __u32 sector_size;
-
- /* 2^16 stripes is quite a lot, a second limit is the size of a single
- * item in the btree
- */
- __u16 num_stripes;
-
- /* sub stripes only matter for raid10 */
- __u16 sub_stripes;
- struct btrfs_stripe stripe;
- /* additional stripes go here */
-} __attribute__ ((__packed__));
-
-#define BTRFS_FREE_SPACE_EXTENT 1
-#define BTRFS_FREE_SPACE_BITMAP 2
-
-struct btrfs_free_space_entry {
- __u64 offset;
- __u64 bytes;
- __u8 type;
-} __attribute__ ((__packed__));
-
-struct btrfs_free_space_header {
- struct btrfs_key location;
- __u64 generation;
- __u64 num_entries;
- __u64 num_bitmaps;
-} __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)
-
-
-/*
- * 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 {
- __u64 refs;
- __u64 generation;
- __u64 flags;
-} __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)
-
-/*
- * 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_key key;
- __u8 level;
-} __attribute__ ((__packed__));
-
-struct btrfs_extent_data_ref {
- __u64 root;
- __u64 objectid;
- __u64 offset;
- __u32 count;
-} __attribute__ ((__packed__));
-
-struct btrfs_shared_data_ref {
- __u32 count;
-} __attribute__ ((__packed__));
-
-struct btrfs_extent_inline_ref {
- __u8 type;
- __u64 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 {
- __u64 chunk_tree;
- __u64 chunk_objectid;
- __u64 chunk_offset;
- __u64 length;
- __u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
-} __attribute__ ((__packed__));
-
-struct btrfs_inode_ref {
- __u64 index;
- __u16 name_len;
- /* name goes here */
-} __attribute__ ((__packed__));
-
-struct btrfs_inode_extref {
- __u64 parent_objectid;
- __u64 index;
- __u16 name_len;
- __u8 name[0];
- /* name goes here */
-} __attribute__ ((__packed__));
-
-struct btrfs_timespec {
- __u64 sec;
- __u32 nsec;
-} __attribute__ ((__packed__));
-
-struct btrfs_inode_item {
- /* nfs style generation number */
- __u64 generation;
- /* transid that last touched this inode */
- __u64 transid;
- __u64 size;
- __u64 nbytes;
- __u64 block_group;
- __u32 nlink;
- __u32 uid;
- __u32 gid;
- __u32 mode;
- __u64 rdev;
- __u64 flags;
-
- /* modification sequence number for NFS */
- __u64 sequence;
-
- /*
- * a little future expansion, for more than this we can
- * just grow the inode item and version it
- */
- __u64 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 {
- __u64 end;
-} __attribute__ ((__packed__));
-
-struct btrfs_dir_item {
- struct btrfs_key location;
- __u64 transid;
- __u16 data_len;
- __u16 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;
- __u64 generation;
- __u64 root_dirid;
- __u64 bytenr;
- __u64 byte_limit;
- __u64 bytes_used;
- __u64 last_snapshot;
- __u64 flags;
- __u32 refs;
- struct btrfs_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.
- */
- __u64 generation_v2;
- __u8 uuid[BTRFS_UUID_SIZE];
- __u8 parent_uuid[BTRFS_UUID_SIZE];
- __u8 received_uuid[BTRFS_UUID_SIZE];
- __u64 ctransid; /* updated when an inode changes */
- __u64 otransid; /* trans when created */
- __u64 stransid; /* trans when sent. non-zero for received subvol */
- __u64 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;
- __u64 reserved[8]; /* for future */
-} __attribute__ ((__packed__));
-
-/*
- * this is used for both forward and backward root refs
- */
-struct btrfs_root_ref {
- __u64 dirid;
- __u64 sequence;
- __u16 name_len;
-} __attribute__ ((__packed__));
-
-#define BTRFS_FILE_EXTENT_INLINE 0
-#define BTRFS_FILE_EXTENT_REG 1
-#define BTRFS_FILE_EXTENT_PREALLOC 2
-
-enum btrfs_compression_type {
- BTRFS_COMPRESS_NONE = 0,
- BTRFS_COMPRESS_ZLIB = 1,
- BTRFS_COMPRESS_LZO = 2,
- BTRFS_COMPRESS_ZSTD = 3,
- BTRFS_COMPRESS_TYPES = 3,
- BTRFS_COMPRESS_LAST = 4,
-};
-
-struct btrfs_file_extent_item {
- /*
- * transaction id that created this extent
- */
- __u64 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.
- */
- __u64 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;
- __u16 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.
- */
- __u64 disk_bytenr;
- __u64 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
- */
- __u64 offset;
- /*
- * the logical number of file blocks (no csums included). This
- * always reflects the size uncompressed and without encoding.
- */
- __u64 num_bytes;
-
-} __attribute__ ((__packed__));
-
-struct btrfs_csum_item {
- __u8 csum;
-} __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_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
- BTRFS_SPACE_INFO_GLOBAL_RSV)
-
-enum btrfs_raid_types {
- BTRFS_RAID_RAID10,
- BTRFS_RAID_RAID1,
- BTRFS_RAID_DUP,
- BTRFS_RAID_RAID0,
- BTRFS_RAID_SINGLE,
- BTRFS_RAID_RAID5,
- BTRFS_RAID_RAID6,
- BTRFS_NR_RAID_TYPES
-};
-
-#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_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)
-
-/*
- * 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)
-
-#endif /* __BTRFS_BTRFS_TREE_H__ */
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copied from kernel/include/uapi/linux/btrfs_btree.h.
+ *
+ * Only modified the header.
+ */
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __BTRFS_TREE_H__
+#define __BTRFS_TREE_H__
+
+#include <linux/types.h>
+
+#define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */
+
+/*
+ * The max metadata block size (node size).
+ *
+ * This limit is somewhat artificial. The memmove and tree block locking cost
+ * go up with larger node size.
+ */
+#define BTRFS_MAX_METADATA_BLOCKSIZE 65536
+
+/*
+ * We can actually store much bigger names, but lets not confuse the rest
+ * of linux.
+ *
+ * btrfs_dir_item::name_len follows this limitation.
+ */
+#define BTRFS_NAME_LEN 255
+
+/*
+ * Objectids start from here.
+ *
+ * Check btrfs_disk_key for the meaning of objectids.
+ */
+
+/*
+ * Root tree holds pointers to all of the tree roots.
+ * Without special mention, the root tree contains the root bytenr of all other
+ * trees, except the chunk tree and the log tree.
+ *
+ * The super block contains the root bytenr of this tree.
+ */
+#define BTRFS_ROOT_TREE_OBJECTID 1ULL
+
+/*
+ * Extent tree stores information about which extents are in use, and backrefs
+ * for each extent.
+ */
+#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
+
+/*
+ * Chunk tree stores btrfs logical address -> physical address mapping.
+ *
+ * The super block contains part of chunk tree for bootstrap, and contains
+ * the root bytenr of this tree.
+ */
+#define BTRFS_CHUNK_TREE_OBJECTID 3ULL
+
+/*
+ * Device tree stores info about which areas of a given device are in use,
+ * and physical address -> btrfs logical address mapping.
+ */
+#define BTRFS_DEV_TREE_OBJECTID 4ULL
+
+/* The fs tree is the first subvolume tree, storing files and directories. */
+#define BTRFS_FS_TREE_OBJECTID 5ULL
+
+/* Shows the directory objectid inside the root tree. */
+#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
+
+/* Csum tree holds checksums of all the data extents. */
+#define BTRFS_CSUM_TREE_OBJECTID 7ULL
+
+/* Quota tree holds quota configuration and tracking. */
+#define BTRFS_QUOTA_TREE_OBJECTID 8ULL
+
+/* UUID tree stores items that use the BTRFS_UUID_KEY* types. */
+#define BTRFS_UUID_TREE_OBJECTID 9ULL
+
+/* Free space cache tree (v2 space cache) tracks free space in block groups. */
+#define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
+
+/* Indicates 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
+
+/* Orhpan 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, shared between the csum tree and log trees. */
+#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
+
+/* For storing free space cache (v1 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
+ * (BTRFS_DEV_ITEMS_OBJECTID, 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
+
+/*
+ * Types start from here.
+ *
+ * Check btrfs_disk_key for details about types.
+ */
+
+/*
+ * 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
+/* reserve 2-11 close to the inode for later flexibility */
+#define BTRFS_INODE_REF_KEY 12
+#define BTRFS_INODE_EXTREF_KEY 13
+#define BTRFS_XATTR_ITEM_KEY 24
+#define BTRFS_ORPHAN_ITEM_KEY 48
+
+/*
+ * Dir items are the name -> inode pointers in a directory.
+ *
+ * There is one for every name in a directory.
+ */
+#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
+
+/* Stores info (position, size ...) about a data extent of a file */
+#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 tree.
+ *
+ * These record which blocks are used, and how many references there are.
+ */
+#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
+
+#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.
+ *
+ * Stores how many free space there is in a block group.
+ */
+#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
+
+/*
+ * 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).
+ */
+#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
+
+
+
+/* 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
+
+#define BTRFS_FSID_SIZE 16
+#define BTRFS_UUID_SIZE 16
+
+/*
+ * The key defines the order in the tree, and so it also defines (optimal)
+ * block layout.
+ *
+ * Objectid and offset are interpreted based on type.
+ * While normally for objectid, it either represents a root number, or an
+ * inode number.
+ *
+ * Type tells us things about the object, and is a kind of stream selector.
+ * Check the following URL for full references about btrfs_disk_key/btrfs_key:
+ * https://btrfs.wiki.kernel.org/index.php/Btree_Items
+ *
+ * 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__));
+
+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;
+
+ /* Optimal seek speed 0-100 where 100 is fastest */
+ __u8 seek_speed;
+
+ /* Optimal 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__));
+
+#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__));
+
+#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 tree 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)
+
+/* Use full backrefs for extent pointers in the block */
+#define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8)
+
+/*
+ * 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_inline_ref {
+ __u8 type;
+ __le64 offset;
+} __attribute__ ((__packed__));
+
+/* Old style backrefs item */
+struct btrfs_extent_ref_v0 {
+ __le64 root;
+ __le64 generation;
+ __le64 objectid;
+ __le32 count;
+} __attribute__ ((__packed__));
+
+
+/* Dev extents record used 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[0];
+ /* Name goes here */
+} __attribute__ ((__packed__));
+
+struct btrfs_timespec {
+ __le64 sec;
+ __le32 nsec;
+} __attribute__ ((__packed__));
+
+/* Inode flags */
+#define BTRFS_INODE_NODATASUM (1 << 0)
+#define BTRFS_INODE_NODATACOW (1 << 1)
+#define BTRFS_INODE_READONLY (1 << 2)
+#define BTRFS_INODE_NOCOMPRESS (1 << 3)
+#define BTRFS_INODE_PREALLOC (1 << 4)
+#define BTRFS_INODE_SYNC (1 << 5)
+#define BTRFS_INODE_IMMUTABLE (1 << 6)
+#define BTRFS_INODE_APPEND (1 << 7)
+#define BTRFS_INODE_NODUMP (1 << 8)
+#define BTRFS_INODE_NOATIME (1 << 9)
+#define BTRFS_INODE_DIRSYNC (1 << 10)
+#define BTRFS_INODE_COMPRESS (1 << 11)
+
+#define BTRFS_INODE_ROOT_ITEM_INIT (1 << 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)
+
+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__));
+
+/* 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__));
+
+/*
+ * Stores 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,
+};
+
+enum btrfs_compression_type {
+ BTRFS_COMPRESS_NONE = 0,
+ BTRFS_COMPRESS_ZLIB = 1,
+ BTRFS_COMPRESS_LZO = 2,
+ BTRFS_COMPRESS_ZSTD = 3,
+ BTRFS_NR_COMPRESS_TYPES = 4,
+};
+
+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 not 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 inside the file extent.
+ *
+ * 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 bytes this file extent is referencing (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__));
+
+enum btrfs_dev_stat_values {
+ /* Disk I/O failure stats */
+ BTRFS_DEV_STAT_WRITE_ERRS, /* EIO or EREMOTEIO from lower layers */
+ BTRFS_DEV_STAT_READ_ERRS, /* EIO or EREMOTEIO from lower layers */
+ BTRFS_DEV_STAT_FLUSH_ERRS, /* EIO or EREMOTEIO from lower layers */
+
+ /* Stats for indirect indications for I/O failures */
+ BTRFS_DEV_STAT_CORRUPTION_ERRS, /* Checksum error, bytenr error or
+ * contents is illegal: this is an
+ * indication that the block was damaged
+ * during read or write, or written to
+ * wrong location or read from wrong
+ * location */
+ BTRFS_DEV_STAT_GENERATION_ERRS, /* An indication that blocks have not
+ * been written */
+
+ BTRFS_DEV_STAT_VALUES_MAX
+};
+
+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)
+
+enum btrfs_raid_types {
+ BTRFS_RAID_RAID10,
+ BTRFS_RAID_RAID1,
+ BTRFS_RAID_DUP,
+ BTRFS_RAID_RAID0,
+ BTRFS_RAID_SINGLE,
+ BTRFS_RAID_RAID5,
+ BTRFS_RAID_RAID6,
+ BTRFS_RAID_RAID1C3,
+ BTRFS_RAID_RAID1C4,
+ BTRFS_NR_RAID_TYPES
+};
+
+#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 __u64 btrfs_qgroup_level(__u64 qgroupid)
+{
+ return qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT;
+}
+
+/* Is subvolume quota turned on? */
+#define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0)
+
+/* Is qgroup rescan running? */
+#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.
+ */
+#define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2)
+
+#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__));
+
+/*
+ * Flags definition for qgroup limits
+ *
+ * Used by:
+ * struct btrfs_qgroup_limit.flags
+ * struct btrfs_qgroup_limit_item.flags
+ */
+#define BTRFS_QGROUP_LIMIT_MAX_RFER (1ULL << 0)
+#define BTRFS_QGROUP_LIMIT_MAX_EXCL (1ULL << 1)
+#define BTRFS_QGROUP_LIMIT_RSV_RFER (1ULL << 2)
+#define BTRFS_QGROUP_LIMIT_RSV_EXCL (1ULL << 3)
+#define BTRFS_QGROUP_LIMIT_RFER_CMPR (1ULL << 4)
+#define BTRFS_QGROUP_LIMIT_EXCL_CMPR (1ULL << 5)
+
+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__));
+
+/*
+ * 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__));
+
+/*
+ * 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
+
+#define BTRFS_LABEL_SIZE 256
+
+/* 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];
+ __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 __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];
+
+ /* Future expansion */
+ __le64 reserved[28];
+ u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
+ struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
+} __attribute__ ((__packed__));
+
+/*
+ * Feature flags
+ *
+ * Used by:
+ * struct btrfs_super_block::(compat|compat_ro|incompat)_flags
+ * struct btrfs_ioctl_feature_flags
+ */
+#define BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE (1ULL << 0)
+
+/*
+ * Older kernels (< 4.9) on big-endian systems produced broken free space tree
+ * bitmaps, and btrfs-progs also used to corrupt the free space tree (versions
+ * < 4.7.3). If this bit is clear, then the free space tree cannot be trusted.
+ * btrfs-progs can also intentionally clear this bit to ask the kernel to
+ * rebuild the free space tree, however this might not work on older kernels
+ * that do not know about this bit. If not sure, clear the cache manually on
+ * first mount when booting older kernel versions.
+ */
+#define BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID (1ULL << 1)
+
+#define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF (1ULL << 0)
+#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL (1ULL << 1)
+#define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS (1ULL << 2)
+#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO (1ULL << 3)
+#define BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD (1ULL << 4)
+
+/*
+ * Older kernels tried to do bigger metadata blocks, but the
+ * code was pretty buggy. Lets not let them try anymore.
+ */
+#define BTRFS_FEATURE_INCOMPAT_BIG_METADATA (1ULL << 5)
+
+#define BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF (1ULL << 6)
+#define BTRFS_FEATURE_INCOMPAT_RAID56 (1ULL << 7)
+#define BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA (1ULL << 8)
+#define BTRFS_FEATURE_INCOMPAT_NO_HOLES (1ULL << 9)
+#define BTRFS_FEATURE_INCOMPAT_METADATA_UUID (1ULL << 10)
+#define BTRFS_FEATURE_INCOMPAT_RAID1C34 (1ULL << 11)
+
+/*
+ * Compat flags that we support.
+ *
+ * If any incompat flags are set other than the ones specified below then we
+ * will fail to mount.
+ */
+#define BTRFS_FEATURE_COMPAT_SUPP 0ULL
+#define BTRFS_FEATURE_COMPAT_SAFE_SET 0ULL
+#define BTRFS_FEATURE_COMPAT_SAFE_CLEAR 0ULL
+
+#define BTRFS_FEATURE_COMPAT_RO_SUPP \
+ (BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE | \
+ BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE_VALID)
+
+#define BTRFS_FEATURE_COMPAT_RO_SAFE_SET 0ULL
+#define BTRFS_FEATURE_COMPAT_RO_SAFE_CLEAR 0ULL
+
+#define BTRFS_FEATURE_INCOMPAT_SUPP \
+ (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF | \
+ BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL | \
+ BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS | \
+ BTRFS_FEATURE_INCOMPAT_BIG_METADATA | \
+ BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO | \
+ BTRFS_FEATURE_INCOMPAT_COMPRESS_ZSTD | \
+ BTRFS_FEATURE_INCOMPAT_RAID56 | \
+ BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF | \
+ BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA | \
+ BTRFS_FEATURE_INCOMPAT_NO_HOLES | \
+ BTRFS_FEATURE_INCOMPAT_METADATA_UUID | \
+ BTRFS_FEATURE_INCOMPAT_RAID1C34)
+
+#define BTRFS_FEATURE_INCOMPAT_SAFE_SET \
+ (BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
+#define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR 0ULL
+
+#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
+
+#define BTRFS_MAX_LEVEL 8
+
+/* 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];
+ u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+ __le64 bytenr; /* Which block this node is supposed to live in */
+ __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__));
+
+/*
+ * 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 children
+ * 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__));
+
+#endif /* __BTRFS_TREE_H__ */
projects / u-boot.git / commitdiff