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fs: btrfs: Add btrfs_tree.h and ctree.h from Linux (and modified)

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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
master
Marek Behún 8 years ago committed by Tom Rini
parent 59981e6a3d
commit d4a704af5d
2 changed files with 1100 additions and 0 deletions
  1. 766
      fs/btrfs/btrfs_tree.h
  2. 334
      fs/btrfs/ctree.h

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fs/btrfs/btrfs_tree.h
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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__ */

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fs/btrfs/ctree.h
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/*
* 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__ */
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