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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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
/* Holds details of remapped addresses after relocation. */#define BTRFS_REMAP_TREE_OBJECTID 13ULL
/* device stats in the device tree */#define BTRFS_DEV_STATS_OBJECTID 0ULL
/* for storing balance parameters in the root tree */#define BTRFS_BALANCE_OBJECTID -4ULL
/* orphan objectid for tracking unlinked/truncated files */#define BTRFS_ORPHAN_OBJECTID -5ULL
/* does write ahead logging to speed up fsyncs */#define BTRFS_TREE_LOG_OBJECTID -6ULL#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
/* for space balancing */#define BTRFS_TREE_RELOC_OBJECTID -8ULL#define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
/* * extent checksums all have this objectid * this allows them to share the logging tree * for fsyncs */#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
/* For storing free space cache */#define BTRFS_FREE_SPACE_OBJECTID -11ULL
/* * The inode number assigned to the special inode for storing * free ino cache */#define BTRFS_FREE_INO_OBJECTID -12ULL
/* dummy objectid represents multiple objectids */#define BTRFS_MULTIPLE_OBJECTIDS -255ULL
/* * All files have objectids in this range. */#define BTRFS_FIRST_FREE_OBJECTID 256ULL#define BTRFS_LAST_FREE_OBJECTID -256ULL#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
/* * the device items go into the chunk tree. The key is in the form * [ 1 BTRFS_DEV_ITEM_KEY device_id ] */#define BTRFS_DEV_ITEMS_OBJECTID 1ULL
#define BTRFS_BTREE_INODE_OBJECTID 1
#define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
#define BTRFS_DEV_REPLACE_DEVID 0ULL
/* * inode items have the data typically returned from stat and store other * info about object characteristics. There is one for every file and dir in * the FS */#define BTRFS_INODE_ITEM_KEY 1#define BTRFS_INODE_REF_KEY 12#define BTRFS_INODE_EXTREF_KEY 13#define BTRFS_XATTR_ITEM_KEY 24
/* * fs verity items are stored under two different key types on disk. * The descriptor items: * [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ] * * At offset 0, we store a btrfs_verity_descriptor_item which tracks the size * of the descriptor item and some extra data for encryption. * Starting at offset 1, these hold the generic fs verity descriptor. The * latter are opaque to btrfs, we just read and write them as a blob for the * higher level verity code. The most common descriptor size is 256 bytes. * * The merkle tree items: * [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ] * * These also start at offset 0, and correspond to the merkle tree bytes. When * fsverity asks for page 0 of the merkle tree, we pull up one page starting at * offset 0 for this key type. These are also opaque to btrfs, we're blindly * storing whatever fsverity sends down. */#define BTRFS_VERITY_DESC_ITEM_KEY 36#define BTRFS_VERITY_MERKLE_ITEM_KEY 37
#define BTRFS_ORPHAN_ITEM_KEY 48/* reserve 2-15 close to the inode for later flexibility */
/* * dir items are the name -> inode pointers in a directory. There is one * for every name in a directory. BTRFS_DIR_LOG_ITEM_KEY is no longer used * but it's still defined here for documentation purposes and to help avoid * having its numerical value reused in the future. */#define BTRFS_DIR_LOG_ITEM_KEY 60#define BTRFS_DIR_LOG_INDEX_KEY 72#define BTRFS_DIR_ITEM_KEY 84#define BTRFS_DIR_INDEX_KEY 96/* * extent data is for file data */#define BTRFS_EXTENT_DATA_KEY 108
/* * extent csums are stored in a separate tree and hold csums for * an entire extent on disk. */#define BTRFS_EXTENT_CSUM_KEY 128
/* * root items point to tree roots. They are typically in the root * tree used by the super block to find all the other trees */#define BTRFS_ROOT_ITEM_KEY 132
/* * root backrefs tie subvols and snapshots to the directory entries that * reference them */#define BTRFS_ROOT_BACKREF_KEY 144
/* * root refs make a fast index for listing all of the snapshots and * subvolumes referenced by a given root. They point directly to the * directory item in the root that references the subvol */#define BTRFS_ROOT_REF_KEY 156
/* * extent items are in the extent map tree. These record which blocks * are used, and how many references there are to each block */#define BTRFS_EXTENT_ITEM_KEY 168
/* * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know * the length, so we save the level in key->offset instead of the length. */#define BTRFS_METADATA_ITEM_KEY 169
/* * Special inline ref key which stores the id of the subvolume which originally * created the extent. This subvolume owns the extent permanently from the * perspective of simple quotas. Needed to know which subvolume to free quota * usage from when the extent is deleted. * * Stored as an inline ref rather to avoid wasting space on a separate item on * top of the existing extent item. However, unlike the other inline refs, * there is one one owner ref per extent rather than one per extent. * * Because of this, it goes at the front of the list of inline refs, and thus * must have a lower type value than any other inline ref type (to satisfy the * disk format rule that inline refs have non-decreasing type). */#define BTRFS_EXTENT_OWNER_REF_KEY 172
#define BTRFS_TREE_BLOCK_REF_KEY 176
#define BTRFS_EXTENT_DATA_REF_KEY 178
/* * Obsolete key. Defintion removed in 6.6, value may be reused in the future. * * #define BTRFS_EXTENT_REF_V0_KEY 180 */
#define BTRFS_SHARED_BLOCK_REF_KEY 182
#define BTRFS_SHARED_DATA_REF_KEY 184
/* * block groups give us hints into the extent allocation trees. Which * blocks are free etc etc */#define BTRFS_BLOCK_GROUP_ITEM_KEY 192
/* * Every block group is represented in the free space tree by a free space info * item, which stores some accounting information. It is keyed on * (block_group_start, FREE_SPACE_INFO, block_group_length). */#define BTRFS_FREE_SPACE_INFO_KEY 198
/* * A free space extent tracks an extent of space that is free in a block group. * It is keyed on (start, FREE_SPACE_EXTENT, length). */#define BTRFS_FREE_SPACE_EXTENT_KEY 199
/* * When a block group becomes very fragmented, we convert it to use bitmaps * instead of extents. A free space bitmap is keyed on * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with * (length / sectorsize) bits. */#define BTRFS_FREE_SPACE_BITMAP_KEY 200
#define BTRFS_DEV_EXTENT_KEY 204#define BTRFS_DEV_ITEM_KEY 216#define BTRFS_CHUNK_ITEM_KEY 228
#define BTRFS_RAID_STRIPE_KEY 230
#define BTRFS_IDENTITY_REMAP_KEY 234#define BTRFS_REMAP_KEY 235#define BTRFS_REMAP_BACKREF_KEY 236
/* * 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 4struct 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; __le64 remap_root; __le64 remap_root_generation; __u8 remap_root_level;
/* Future expansion */ __u8 reserved[199]; __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__));
struct btrfs_stripe_extent { /* An array of raid strides this stripe is composed of. */ __DECLARE_FLEX_ARRAY(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)
/* * Those are temporaray flags utilized by btrfs-progs to do offline conversion. * They are rejected by kernel. * But still keep them all here to avoid conflicts. */#define BTRFS_SUPER_FLAG_CHANGING_BG_TREE (1ULL << 38)#define BTRFS_SUPER_FLAG_CHANGING_DATA_CSUM (1ULL << 39)#define BTRFS_SUPER_FLAG_CHANGING_META_CSUM (1ULL << 40)
/* * 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_REMAPPED (1ULL << 11)#define BTRFS_BLOCK_GROUP_METADATA_REMAP (1ULL << 12)#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 | \ BTRFS_BLOCK_GROUP_METADATA_REMAP)
#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_block_group_item_v2 { __le64 used; __le64 chunk_objectid; __le64 flags; __le64 remap_bytes; __le32 identity_remap_count;} __attribute__ ((__packed__));
struct btrfs_free_space_info { __le32 extent_count; __le32 flags;} __attribute__ ((__packed__));
#define BTRFS_FREE_SPACE_USING_BITMAPS (1UL << 0)#define BTRFS_FREE_SPACE_FLAGS_MASK (BTRFS_FREE_SPACE_USING_BITMAPS)
#define BTRFS_QGROUP_LEVEL_SHIFT 48static inline __u16 btrfs_qgroup_level(__u64 qgroupid){ return (__u16)(qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT);}
/* * is subvolume quota turned on? */#define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0)/* * RESCAN is set during the initialization phase */#define BTRFS_QGROUP_STATUS_FLAG_RESCAN (1ULL << 1)/* * Some qgroup entries are known to be out of date, * either because the configuration has changed in a way that * makes a rescan necessary, or because the fs has been mounted * with a non-qgroup-aware version. * Turning qouta off and on again makes it inconsistent, too. */#define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2)
/* * Whether or not this filesystem is using simple quotas. Not exactly the * incompat bit, because we support using simple quotas, disabling it, then * going back to full qgroup quotas. */#define BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE (1ULL << 3)
#define BTRFS_QGROUP_STATUS_FLAGS_MASK (BTRFS_QGROUP_STATUS_FLAG_ON | \ BTRFS_QGROUP_STATUS_FLAG_RESCAN | \ BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT | \ BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE)
#define BTRFS_QGROUP_STATUS_VERSION 1
struct btrfs_qgroup_status_item { __le64 version; /* * the generation is updated during every commit. As older * versions of btrfs are not aware of qgroups, it will be * possible to detect inconsistencies by checking the * generation on mount time */ __le64 generation;
/* flag definitions see above */ __le64 flags;
/* * only used during scanning to record the progress * of the scan. It contains a logical address */ __le64 rescan;
/* * The generation when quotas were last enabled. Used by simple quotas to * avoid decrementing when freeing an extent that was written before * enable. * * Set only if flags contain BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE. */ __le64 enable_gen;} __attribute__ ((__packed__));
struct btrfs_qgroup_info_item { __le64 generation; __le64 rfer; __le64 rfer_cmpr; __le64 excl; __le64 excl_cmpr;} __attribute__ ((__packed__));
struct btrfs_qgroup_limit_item { /* * only updated when any of the other values change */ __le64 flags; __le64 max_rfer; __le64 max_excl; __le64 rsv_rfer; __le64 rsv_excl;} __attribute__ ((__packed__));
struct btrfs_verity_descriptor_item { /* Size of the verity descriptor in bytes */ __le64 size; /* * When we implement support for fscrypt, we will need to encrypt the * Merkle tree for encrypted verity files. These 128 bits are for the * eventual storage of an fscrypt initialization vector. */ __le64 reserved[2]; __u8 encryption;} __attribute__ ((__packed__));
/* * For a range identified by a BTRFS_REMAP_KEY item in the remap tree, gives * the address that the start of the range will get remapped to. This * structure is also shared by BTRFS_REMAP_BACKREF_KEY. */struct btrfs_remap_item { __le64 address;} __attribute__ ((__packed__));
#endif /* _BTRFS_CTREE_H_ */