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
diff --git a/fs/btrfs/btrfs_tree.h b/fs/btrfs/btrfs_tree.h new file mode 100644 index 0000000000..f171b24288 --- /dev/null +++ b/fs/btrfs/btrfs_tree.h @@ -0,0 +1,766 @@ +/* + * 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__ */ diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h new file mode 100644 index 0000000000..39f4473ae5 --- /dev/null +++ b/fs/btrfs/ctree.h @@ -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__ */