new file mode 100644
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+/*
+ * From linux/include/uapi/linux/btrfs_tree.h
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#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_TYPES = 2,
+ BTRFS_COMPRESS_LAST = 3,
+};
+
+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__ */
new file mode 100644
@@ -0,0 +1,334 @@
+/*
+ * From linux/fs/btrfs/ctree.h
+ * Copyright (C) 2007,2008 Oracle. All rights reserved.
+ *
+ * Modified in 2017 by Marek Behun, CZ.NIC, marek.behun@nic.cz
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifndef __BTRFS_CTREE_H__
+#define __BTRFS_CTREE_H__
+
+#include <common.h>
+#include <compiler.h>
+#include "btrfs_tree.h"
+
+#define BTRFS_MAGIC 0x4D5F53665248425FULL /* ascii _BHRfS_M, no null */
+
+#define BTRFS_MAX_MIRRORS 3
+
+#define BTRFS_MAX_LEVEL 8
+
+#define BTRFS_COMPAT_EXTENT_TREE_V0
+
+/*
+ * the max metadata block size. This limit is somewhat artificial,
+ * but the memmove costs go through the roof for larger blocks.
+ */
+#define BTRFS_MAX_METADATA_BLOCKSIZE 65536
+
+/*
+ * 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
+
+static const int btrfs_csum_sizes[] = { 4 };
+
+/* four bytes for CRC32 */
+#define BTRFS_EMPTY_DIR_SIZE 0
+
+/* ioprio of readahead is set to idle */
+#define BTRFS_IOPRIO_READA (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0))
+
+#define BTRFS_DIRTY_METADATA_THRESH SZ_32M
+
+#define BTRFS_MAX_EXTENT_SIZE SZ_128M
+
+/*
+ * File system states
+ */
+#define BTRFS_FS_STATE_ERROR 0
+#define BTRFS_FS_STATE_REMOUNTING 1
+#define BTRFS_FS_STATE_TRANS_ABORTED 2
+#define BTRFS_FS_STATE_DEV_REPLACING 3
+#define BTRFS_FS_STATE_DUMMY_FS_INFO 4
+
+#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
+
+/*
+ * 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 */
+ __u64 bytenr; /* which block this node is supposed to live in */
+ __u64 flags;
+
+ /* allowed to be different from the super from here on down */
+ __u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
+ __u64 generation;
+ __u64 owner;
+ __u32 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 {
+ __u64 tree_root;
+ __u64 tree_root_gen;
+
+ __u64 chunk_root;
+ __u64 chunk_root_gen;
+
+ __u64 extent_root;
+ __u64 extent_root_gen;
+
+ __u64 fs_root;
+ __u64 fs_root_gen;
+
+ __u64 dev_root;
+ __u64 dev_root_gen;
+
+ __u64 csum_root;
+ __u64 csum_root_gen;
+
+ __u64 total_bytes;
+ __u64 bytes_used;
+ __u64 num_devices;
+ /* future */
+ __u64 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__));
+
+/*
+ * the super block basically lists the main trees of the FS
+ * it currently lacks any block count etc etc
+ */
+struct btrfs_super_block {
+ __u8 csum[BTRFS_CSUM_SIZE];
+ /* the first 4 fields must match struct btrfs_header */
+ __u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
+ __u64 bytenr; /* this block number */
+ __u64 flags;
+
+ /* allowed to be different from the btrfs_header from here own down */
+ __u64 magic;
+ __u64 generation;
+ __u64 root;
+ __u64 chunk_root;
+ __u64 log_root;
+
+ /* this will help find the new super based on the log root */
+ __u64 log_root_transid;
+ __u64 total_bytes;
+ __u64 bytes_used;
+ __u64 root_dir_objectid;
+ __u64 num_devices;
+ __u32 sectorsize;
+ __u32 nodesize;
+ __u32 __unused_leafsize;
+ __u32 stripesize;
+ __u32 sys_chunk_array_size;
+ __u64 chunk_root_generation;
+ __u64 compat_flags;
+ __u64 compat_ro_flags;
+ __u64 incompat_flags;
+ __u16 csum_type;
+ __u8 root_level;
+ __u8 chunk_root_level;
+ __u8 log_root_level;
+ struct btrfs_dev_item dev_item;
+
+ char label[BTRFS_LABEL_SIZE];
+
+ __u64 cache_generation;
+ __u64 uuid_tree_generation;
+
+ /* future expansion */
+ __u64 reserved[30];
+ __u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
+ struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
+} __attribute__ ((__packed__));
+
+/*
+ * 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_RAID56 | \
+ BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF | \
+ BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA | \
+ BTRFS_FEATURE_INCOMPAT_NO_HOLES)
+
+#define BTRFS_FEATURE_INCOMPAT_SAFE_SET \
+ (BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
+#define BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR 0ULL
+
+/*
+ * 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_key key;
+ __u32 offset;
+ __u32 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_key key;
+ __u64 blockptr;
+ __u64 generation;
+} __attribute__ ((__packed__));
+
+struct btrfs_node {
+ struct btrfs_header header;
+ struct btrfs_key_ptr ptrs[];
+} __attribute__ ((__packed__));
+
+union btrfs_tree_node {
+ struct btrfs_header header;
+ struct btrfs_leaf leaf;
+ struct btrfs_node node;
+};
+
+typedef __u8 u8;
+typedef __u16 u16;
+typedef __u32 u32;
+typedef __u64 u64;
+
+struct btrfs_path {
+ union btrfs_tree_node *nodes[BTRFS_MAX_LEVEL];
+ u32 slots[BTRFS_MAX_LEVEL];
+};
+
+struct btrfs_root {
+ u64 objectid;
+ u64 bytenr;
+ u64 root_dirid;
+};
+
+int btrfs_comp_keys(struct btrfs_key *, struct btrfs_key *);
+int btrfs_comp_keys_type(struct btrfs_key *, struct btrfs_key *);
+int btrfs_bin_search(union btrfs_tree_node *, struct btrfs_key *, int *);
+void btrfs_free_path(struct btrfs_path *);
+int btrfs_search_tree(const struct btrfs_root *, struct btrfs_key *,
+ struct btrfs_path *);
+int btrfs_prev_slot(struct btrfs_path *);
+int btrfs_next_slot(struct btrfs_path *);
+
+static inline struct btrfs_key *btrfs_path_leaf_key(struct btrfs_path *p) {
+ return &p->nodes[0]->leaf.items[p->slots[0]].key;
+}
+
+static inline struct btrfs_key *
+btrfs_search_tree_key_type(const struct btrfs_root *root, u64 objectid,
+ u8 type, struct btrfs_path *path)
+{
+ struct btrfs_key key, *res;
+
+ key.objectid = objectid;
+ key.type = type;
+ key.offset = 0;
+
+ if (btrfs_search_tree(root, &key, path))
+ return NULL;
+
+ res = btrfs_path_leaf_key(path);
+ if (btrfs_comp_keys_type(&key, res)) {
+ btrfs_free_path(path);
+ return NULL;
+ }
+
+ return res;
+}
+
+static inline u32 btrfs_path_item_size(struct btrfs_path *p)
+{
+ return p->nodes[0]->leaf.items[p->slots[0]].size;
+}
+
+static inline void *btrfs_leaf_data(struct btrfs_leaf *leaf, u32 slot)
+{
+ return ((u8 *) leaf) + sizeof(struct btrfs_header)
+ + leaf->items[slot].offset;
+}
+
+static inline void *btrfs_path_leaf_data(struct btrfs_path *p)
+{
+ return btrfs_leaf_data(&p->nodes[0]->leaf, p->slots[0]);
+}
+
+#define btrfs_item_ptr(l,s,t) \
+ ((t *) btrfs_leaf_data((l),(s)))
+
+#define btrfs_path_item_ptr(p,t) \
+ ((t *) btrfs_path_leaf_data((p)))
+
+#endif /* __BTRFS_CTREE_H__ */
Add btrfs_tree.h and ctree.h from Linux which contains constants and structures for the BTRFS filesystem. Signed-off-by: Marek Behun <marek.behun@nic.cz> create mode 100644 fs/btrfs/btrfs_tree.h create mode 100644 fs/btrfs/ctree.h