linux-headers (unknown)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _BTRFS_CTREE_H_
3 #define _BTRFS_CTREE_H_
4
5 #include <linux/btrfs.h>
6 #include <linux/types.h>
7 #include <stddef.h>
8
9 /* ASCII for _BHRfS_M, no terminating nul */
10 #define BTRFS_MAGIC 0x4D5F53665248425FULL
11
12 #define BTRFS_MAX_LEVEL 8
13
14 /*
15 * We can actually store much bigger names, but lets not confuse the rest of
16 * linux.
17 */
18 #define BTRFS_NAME_LEN 255
19
20 /*
21 * Theoretical limit is larger, but we keep this down to a sane value. That
22 * should limit greatly the possibility of collisions on inode ref items.
23 */
24 #define BTRFS_LINK_MAX 65535U
25
26 /*
27 * This header contains the structure definitions and constants used
28 * by file system objects that can be retrieved using
29 * the BTRFS_IOC_SEARCH_TREE ioctl. That means basically anything that
30 * is needed to describe a leaf node's key or item contents.
31 */
32
33 /* holds pointers to all of the tree roots */
34 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
35
36 /* stores information about which extents are in use, and reference counts */
37 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL
38
39 /*
40 * chunk tree stores translations from logical -> physical block numbering
41 * the super block points to the chunk tree
42 */
43 #define BTRFS_CHUNK_TREE_OBJECTID 3ULL
44
45 /*
46 * stores information about which areas of a given device are in use.
47 * one per device. The tree of tree roots points to the device tree
48 */
49 #define BTRFS_DEV_TREE_OBJECTID 4ULL
50
51 /* one per subvolume, storing files and directories */
52 #define BTRFS_FS_TREE_OBJECTID 5ULL
53
54 /* directory objectid inside the root tree */
55 #define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
56
57 /* holds checksums of all the data extents */
58 #define BTRFS_CSUM_TREE_OBJECTID 7ULL
59
60 /* holds quota configuration and tracking */
61 #define BTRFS_QUOTA_TREE_OBJECTID 8ULL
62
63 /* for storing items that use the BTRFS_UUID_KEY* types */
64 #define BTRFS_UUID_TREE_OBJECTID 9ULL
65
66 /* tracks free space in block groups. */
67 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
68
69 /* Holds the block group items for extent tree v2. */
70 #define BTRFS_BLOCK_GROUP_TREE_OBJECTID 11ULL
71
72 /* device stats in the device tree */
73 #define BTRFS_DEV_STATS_OBJECTID 0ULL
74
75 /* for storing balance parameters in the root tree */
76 #define BTRFS_BALANCE_OBJECTID -4ULL
77
78 /* orphan objectid for tracking unlinked/truncated files */
79 #define BTRFS_ORPHAN_OBJECTID -5ULL
80
81 /* does write ahead logging to speed up fsyncs */
82 #define BTRFS_TREE_LOG_OBJECTID -6ULL
83 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
84
85 /* for space balancing */
86 #define BTRFS_TREE_RELOC_OBJECTID -8ULL
87 #define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
88
89 /*
90 * extent checksums all have this objectid
91 * this allows them to share the logging tree
92 * for fsyncs
93 */
94 #define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
95
96 /* For storing free space cache */
97 #define BTRFS_FREE_SPACE_OBJECTID -11ULL
98
99 /*
100 * The inode number assigned to the special inode for storing
101 * free ino cache
102 */
103 #define BTRFS_FREE_INO_OBJECTID -12ULL
104
105 /* dummy objectid represents multiple objectids */
106 #define BTRFS_MULTIPLE_OBJECTIDS -255ULL
107
108 /*
109 * All files have objectids in this range.
110 */
111 #define BTRFS_FIRST_FREE_OBJECTID 256ULL
112 #define BTRFS_LAST_FREE_OBJECTID -256ULL
113 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
114
115
116 /*
117 * the device items go into the chunk tree. The key is in the form
118 * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
119 */
120 #define BTRFS_DEV_ITEMS_OBJECTID 1ULL
121
122 #define BTRFS_BTREE_INODE_OBJECTID 1
123
124 #define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
125
126 #define BTRFS_DEV_REPLACE_DEVID 0ULL
127
128 /*
129 * inode items have the data typically returned from stat and store other
130 * info about object characteristics. There is one for every file and dir in
131 * the FS
132 */
133 #define BTRFS_INODE_ITEM_KEY 1
134 #define BTRFS_INODE_REF_KEY 12
135 #define BTRFS_INODE_EXTREF_KEY 13
136 #define BTRFS_XATTR_ITEM_KEY 24
137
138 /*
139 * fs verity items are stored under two different key types on disk.
140 * The descriptor items:
141 * [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ]
142 *
143 * At offset 0, we store a btrfs_verity_descriptor_item which tracks the size
144 * of the descriptor item and some extra data for encryption.
145 * Starting at offset 1, these hold the generic fs verity descriptor. The
146 * latter are opaque to btrfs, we just read and write them as a blob for the
147 * higher level verity code. The most common descriptor size is 256 bytes.
148 *
149 * The merkle tree items:
150 * [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ]
151 *
152 * These also start at offset 0, and correspond to the merkle tree bytes. When
153 * fsverity asks for page 0 of the merkle tree, we pull up one page starting at
154 * offset 0 for this key type. These are also opaque to btrfs, we're blindly
155 * storing whatever fsverity sends down.
156 */
157 #define BTRFS_VERITY_DESC_ITEM_KEY 36
158 #define BTRFS_VERITY_MERKLE_ITEM_KEY 37
159
160 #define BTRFS_ORPHAN_ITEM_KEY 48
161 /* reserve 2-15 close to the inode for later flexibility */
162
163 /*
164 * dir items are the name -> inode pointers in a directory. There is one
165 * for every name in a directory. BTRFS_DIR_LOG_ITEM_KEY is no longer used
166 * but it's still defined here for documentation purposes and to help avoid
167 * having its numerical value reused in the future.
168 */
169 #define BTRFS_DIR_LOG_ITEM_KEY 60
170 #define BTRFS_DIR_LOG_INDEX_KEY 72
171 #define BTRFS_DIR_ITEM_KEY 84
172 #define BTRFS_DIR_INDEX_KEY 96
173 /*
174 * extent data is for file data
175 */
176 #define BTRFS_EXTENT_DATA_KEY 108
177
178 /*
179 * extent csums are stored in a separate tree and hold csums for
180 * an entire extent on disk.
181 */
182 #define BTRFS_EXTENT_CSUM_KEY 128
183
184 /*
185 * root items point to tree roots. They are typically in the root
186 * tree used by the super block to find all the other trees
187 */
188 #define BTRFS_ROOT_ITEM_KEY 132
189
190 /*
191 * root backrefs tie subvols and snapshots to the directory entries that
192 * reference them
193 */
194 #define BTRFS_ROOT_BACKREF_KEY 144
195
196 /*
197 * root refs make a fast index for listing all of the snapshots and
198 * subvolumes referenced by a given root. They point directly to the
199 * directory item in the root that references the subvol
200 */
201 #define BTRFS_ROOT_REF_KEY 156
202
203 /*
204 * extent items are in the extent map tree. These record which blocks
205 * are used, and how many references there are to each block
206 */
207 #define BTRFS_EXTENT_ITEM_KEY 168
208
209 /*
210 * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
211 * the length, so we save the level in key->offset instead of the length.
212 */
213 #define BTRFS_METADATA_ITEM_KEY 169
214
215 #define BTRFS_TREE_BLOCK_REF_KEY 176
216
217 #define BTRFS_EXTENT_DATA_REF_KEY 178
218
219 #define BTRFS_EXTENT_REF_V0_KEY 180
220
221 #define BTRFS_SHARED_BLOCK_REF_KEY 182
222
223 #define BTRFS_SHARED_DATA_REF_KEY 184
224
225 /*
226 * block groups give us hints into the extent allocation trees. Which
227 * blocks are free etc etc
228 */
229 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192
230
231 /*
232 * Every block group is represented in the free space tree by a free space info
233 * item, which stores some accounting information. It is keyed on
234 * (block_group_start, FREE_SPACE_INFO, block_group_length).
235 */
236 #define BTRFS_FREE_SPACE_INFO_KEY 198
237
238 /*
239 * A free space extent tracks an extent of space that is free in a block group.
240 * It is keyed on (start, FREE_SPACE_EXTENT, length).
241 */
242 #define BTRFS_FREE_SPACE_EXTENT_KEY 199
243
244 /*
245 * When a block group becomes very fragmented, we convert it to use bitmaps
246 * instead of extents. A free space bitmap is keyed on
247 * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with
248 * (length / sectorsize) bits.
249 */
250 #define BTRFS_FREE_SPACE_BITMAP_KEY 200
251
252 #define BTRFS_DEV_EXTENT_KEY 204
253 #define BTRFS_DEV_ITEM_KEY 216
254 #define BTRFS_CHUNK_ITEM_KEY 228
255
256 /*
257 * Records the overall state of the qgroups.
258 * There's only one instance of this key present,
259 * (0, BTRFS_QGROUP_STATUS_KEY, 0)
260 */
261 #define BTRFS_QGROUP_STATUS_KEY 240
262 /*
263 * Records the currently used space of the qgroup.
264 * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
265 */
266 #define BTRFS_QGROUP_INFO_KEY 242
267 /*
268 * Contains the user configured limits for the qgroup.
269 * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
270 */
271 #define BTRFS_QGROUP_LIMIT_KEY 244
272 /*
273 * Records the child-parent relationship of qgroups. For
274 * each relation, 2 keys are present:
275 * (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
276 * (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
277 */
278 #define BTRFS_QGROUP_RELATION_KEY 246
279
280 /*
281 * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
282 */
283 #define BTRFS_BALANCE_ITEM_KEY 248
284
285 /*
286 * The key type for tree items that are stored persistently, but do not need to
287 * exist for extended period of time. The items can exist in any tree.
288 *
289 * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
290 *
291 * Existing items:
292 *
293 * - balance status item
294 * (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
295 */
296 #define BTRFS_TEMPORARY_ITEM_KEY 248
297
298 /*
299 * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY
300 */
301 #define BTRFS_DEV_STATS_KEY 249
302
303 /*
304 * The key type for tree items that are stored persistently and usually exist
305 * for a long period, eg. filesystem lifetime. The item kinds can be status
306 * information, stats or preference values. The item can exist in any tree.
307 *
308 * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
309 *
310 * Existing items:
311 *
312 * - device statistics, store IO stats in the device tree, one key for all
313 * stats
314 * (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
315 */
316 #define BTRFS_PERSISTENT_ITEM_KEY 249
317
318 /*
319 * Persistently stores the device replace state in the device tree.
320 * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
321 */
322 #define BTRFS_DEV_REPLACE_KEY 250
323
324 /*
325 * Stores items that allow to quickly map UUIDs to something else.
326 * These items are part of the filesystem UUID tree.
327 * The key is built like this:
328 * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
329 */
330 #if BTRFS_UUID_SIZE != 16
331 #error "UUID items require BTRFS_UUID_SIZE == 16!"
332 #endif
333 #define BTRFS_UUID_KEY_SUBVOL 251 /* for UUIDs assigned to subvols */
334 #define BTRFS_UUID_KEY_RECEIVED_SUBVOL 252 /* for UUIDs assigned to
335 * received subvols */
336
337 /*
338 * string items are for debugging. They just store a short string of
339 * data in the FS
340 */
341 #define BTRFS_STRING_ITEM_KEY 253
342
343 /* Maximum metadata block size (nodesize) */
344 #define BTRFS_MAX_METADATA_BLOCKSIZE 65536
345
346 /* 32 bytes in various csum fields */
347 #define BTRFS_CSUM_SIZE 32
348
349 /* csum types */
350 enum btrfs_csum_type {
351 BTRFS_CSUM_TYPE_CRC32 = 0,
352 BTRFS_CSUM_TYPE_XXHASH = 1,
353 BTRFS_CSUM_TYPE_SHA256 = 2,
354 BTRFS_CSUM_TYPE_BLAKE2 = 3,
355 };
356
357 /*
358 * flags definitions for directory entry item type
359 *
360 * Used by:
361 * struct btrfs_dir_item.type
362 *
363 * Values 0..7 must match common file type values in fs_types.h.
364 */
365 #define BTRFS_FT_UNKNOWN 0
366 #define BTRFS_FT_REG_FILE 1
367 #define BTRFS_FT_DIR 2
368 #define BTRFS_FT_CHRDEV 3
369 #define BTRFS_FT_BLKDEV 4
370 #define BTRFS_FT_FIFO 5
371 #define BTRFS_FT_SOCK 6
372 #define BTRFS_FT_SYMLINK 7
373 #define BTRFS_FT_XATTR 8
374 #define BTRFS_FT_MAX 9
375 /* Directory contains encrypted data */
376 #define BTRFS_FT_ENCRYPTED 0x80
377
378 static __inline__ __u8 btrfs_dir_flags_to_ftype(__u8 flags)
379 {
380 return flags & ~BTRFS_FT_ENCRYPTED;
381 }
382
383 /*
384 * Inode flags
385 */
386 #define BTRFS_INODE_NODATASUM (1U << 0)
387 #define BTRFS_INODE_NODATACOW (1U << 1)
388 #define BTRFS_INODE_READONLY (1U << 2)
389 #define BTRFS_INODE_NOCOMPRESS (1U << 3)
390 #define BTRFS_INODE_PREALLOC (1U << 4)
391 #define BTRFS_INODE_SYNC (1U << 5)
392 #define BTRFS_INODE_IMMUTABLE (1U << 6)
393 #define BTRFS_INODE_APPEND (1U << 7)
394 #define BTRFS_INODE_NODUMP (1U << 8)
395 #define BTRFS_INODE_NOATIME (1U << 9)
396 #define BTRFS_INODE_DIRSYNC (1U << 10)
397 #define BTRFS_INODE_COMPRESS (1U << 11)
398
399 #define BTRFS_INODE_ROOT_ITEM_INIT (1U << 31)
400
401 #define BTRFS_INODE_FLAG_MASK \
402 (BTRFS_INODE_NODATASUM | \
403 BTRFS_INODE_NODATACOW | \
404 BTRFS_INODE_READONLY | \
405 BTRFS_INODE_NOCOMPRESS | \
406 BTRFS_INODE_PREALLOC | \
407 BTRFS_INODE_SYNC | \
408 BTRFS_INODE_IMMUTABLE | \
409 BTRFS_INODE_APPEND | \
410 BTRFS_INODE_NODUMP | \
411 BTRFS_INODE_NOATIME | \
412 BTRFS_INODE_DIRSYNC | \
413 BTRFS_INODE_COMPRESS | \
414 BTRFS_INODE_ROOT_ITEM_INIT)
415
416 #define BTRFS_INODE_RO_VERITY (1U << 0)
417
418 #define BTRFS_INODE_RO_FLAG_MASK (BTRFS_INODE_RO_VERITY)
419
420 /*
421 * The key defines the order in the tree, and so it also defines (optimal)
422 * block layout.
423 *
424 * objectid corresponds to the inode number.
425 *
426 * type tells us things about the object, and is a kind of stream selector.
427 * so for a given inode, keys with type of 1 might refer to the inode data,
428 * type of 2 may point to file data in the btree and type == 3 may point to
429 * extents.
430 *
431 * offset is the starting byte offset for this key in the stream.
432 *
433 * btrfs_disk_key is in disk byte order. struct btrfs_key is always
434 * in cpu native order. Otherwise they are identical and their sizes
435 * should be the same (ie both packed)
436 */
437 struct btrfs_disk_key {
438 __le64 objectid;
439 __u8 type;
440 __le64 offset;
441 } __attribute__ ((__packed__));
442
443 struct btrfs_key {
444 __u64 objectid;
445 __u8 type;
446 __u64 offset;
447 } __attribute__ ((__packed__));
448
449 /*
450 * Every tree block (leaf or node) starts with this header.
451 */
452 struct btrfs_header {
453 /* These first four must match the super block */
454 __u8 csum[BTRFS_CSUM_SIZE];
455 /* FS specific uuid */
456 __u8 fsid[BTRFS_FSID_SIZE];
457 /* Which block this node is supposed to live in */
458 __le64 bytenr;
459 __le64 flags;
460
461 /* Allowed to be different from the super from here on down */
462 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
463 __le64 generation;
464 __le64 owner;
465 __le32 nritems;
466 __u8 level;
467 } __attribute__ ((__packed__));
468
469 /*
470 * This is a very generous portion of the super block, giving us room to
471 * translate 14 chunks with 3 stripes each.
472 */
473 #define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
474
475 /*
476 * Just in case we somehow lose the roots and are not able to mount, we store
477 * an array of the roots from previous transactions in the super.
478 */
479 #define BTRFS_NUM_BACKUP_ROOTS 4
480 struct btrfs_root_backup {
481 __le64 tree_root;
482 __le64 tree_root_gen;
483
484 __le64 chunk_root;
485 __le64 chunk_root_gen;
486
487 __le64 extent_root;
488 __le64 extent_root_gen;
489
490 __le64 fs_root;
491 __le64 fs_root_gen;
492
493 __le64 dev_root;
494 __le64 dev_root_gen;
495
496 __le64 csum_root;
497 __le64 csum_root_gen;
498
499 __le64 total_bytes;
500 __le64 bytes_used;
501 __le64 num_devices;
502 /* future */
503 __le64 unused_64[4];
504
505 __u8 tree_root_level;
506 __u8 chunk_root_level;
507 __u8 extent_root_level;
508 __u8 fs_root_level;
509 __u8 dev_root_level;
510 __u8 csum_root_level;
511 /* future and to align */
512 __u8 unused_8[10];
513 } __attribute__ ((__packed__));
514
515 /*
516 * A leaf is full of items. offset and size tell us where to find the item in
517 * the leaf (relative to the start of the data area)
518 */
519 struct btrfs_item {
520 struct btrfs_disk_key key;
521 __le32 offset;
522 __le32 size;
523 } __attribute__ ((__packed__));
524
525 /*
526 * Leaves have an item area and a data area:
527 * [item0, item1....itemN] [free space] [dataN...data1, data0]
528 *
529 * The data is separate from the items to get the keys closer together during
530 * searches.
531 */
532 struct btrfs_leaf {
533 struct btrfs_header header;
534 struct btrfs_item items[];
535 } __attribute__ ((__packed__));
536
537 /*
538 * All non-leaf blocks are nodes, they hold only keys and pointers to other
539 * blocks.
540 */
541 struct btrfs_key_ptr {
542 struct btrfs_disk_key key;
543 __le64 blockptr;
544 __le64 generation;
545 } __attribute__ ((__packed__));
546
547 struct btrfs_node {
548 struct btrfs_header header;
549 struct btrfs_key_ptr ptrs[];
550 } __attribute__ ((__packed__));
551
552 struct btrfs_dev_item {
553 /* the internal btrfs device id */
554 __le64 devid;
555
556 /* size of the device */
557 __le64 total_bytes;
558
559 /* bytes used */
560 __le64 bytes_used;
561
562 /* optimal io alignment for this device */
563 __le32 io_align;
564
565 /* optimal io width for this device */
566 __le32 io_width;
567
568 /* minimal io size for this device */
569 __le32 sector_size;
570
571 /* type and info about this device */
572 __le64 type;
573
574 /* expected generation for this device */
575 __le64 generation;
576
577 /*
578 * starting byte of this partition on the device,
579 * to allow for stripe alignment in the future
580 */
581 __le64 start_offset;
582
583 /* grouping information for allocation decisions */
584 __le32 dev_group;
585
586 /* seek speed 0-100 where 100 is fastest */
587 __u8 seek_speed;
588
589 /* bandwidth 0-100 where 100 is fastest */
590 __u8 bandwidth;
591
592 /* btrfs generated uuid for this device */
593 __u8 uuid[BTRFS_UUID_SIZE];
594
595 /* uuid of FS who owns this device */
596 __u8 fsid[BTRFS_UUID_SIZE];
597 } __attribute__ ((__packed__));
598
599 struct btrfs_stripe {
600 __le64 devid;
601 __le64 offset;
602 __u8 dev_uuid[BTRFS_UUID_SIZE];
603 } __attribute__ ((__packed__));
604
605 struct btrfs_chunk {
606 /* size of this chunk in bytes */
607 __le64 length;
608
609 /* objectid of the root referencing this chunk */
610 __le64 owner;
611
612 __le64 stripe_len;
613 __le64 type;
614
615 /* optimal io alignment for this chunk */
616 __le32 io_align;
617
618 /* optimal io width for this chunk */
619 __le32 io_width;
620
621 /* minimal io size for this chunk */
622 __le32 sector_size;
623
624 /* 2^16 stripes is quite a lot, a second limit is the size of a single
625 * item in the btree
626 */
627 __le16 num_stripes;
628
629 /* sub stripes only matter for raid10 */
630 __le16 sub_stripes;
631 struct btrfs_stripe stripe;
632 /* additional stripes go here */
633 } __attribute__ ((__packed__));
634
635 /*
636 * The super block basically lists the main trees of the FS.
637 */
638 struct btrfs_super_block {
639 /* The first 4 fields must match struct btrfs_header */
640 __u8 csum[BTRFS_CSUM_SIZE];
641 /* FS specific UUID, visible to user */
642 __u8 fsid[BTRFS_FSID_SIZE];
643 /* This block number */
644 __le64 bytenr;
645 __le64 flags;
646
647 /* Allowed to be different from the btrfs_header from here own down */
648 __le64 magic;
649 __le64 generation;
650 __le64 root;
651 __le64 chunk_root;
652 __le64 log_root;
653
654 /*
655 * This member has never been utilized since the very beginning, thus
656 * it's always 0 regardless of kernel version. We always use
657 * generation + 1 to read log tree root. So here we mark it deprecated.
658 */
659 __le64 __unused_log_root_transid;
660 __le64 total_bytes;
661 __le64 bytes_used;
662 __le64 root_dir_objectid;
663 __le64 num_devices;
664 __le32 sectorsize;
665 __le32 nodesize;
666 __le32 __unused_leafsize;
667 __le32 stripesize;
668 __le32 sys_chunk_array_size;
669 __le64 chunk_root_generation;
670 __le64 compat_flags;
671 __le64 compat_ro_flags;
672 __le64 incompat_flags;
673 __le16 csum_type;
674 __u8 root_level;
675 __u8 chunk_root_level;
676 __u8 log_root_level;
677 struct btrfs_dev_item dev_item;
678
679 char label[BTRFS_LABEL_SIZE];
680
681 __le64 cache_generation;
682 __le64 uuid_tree_generation;
683
684 /* The UUID written into btree blocks */
685 __u8 metadata_uuid[BTRFS_FSID_SIZE];
686
687 __u64 nr_global_roots;
688
689 /* Future expansion */
690 __le64 reserved[27];
691 __u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
692 struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
693
694 /* Padded to 4096 bytes */
695 __u8 padding[565];
696 } __attribute__ ((__packed__));
697
698 #define BTRFS_FREE_SPACE_EXTENT 1
699 #define BTRFS_FREE_SPACE_BITMAP 2
700
701 struct btrfs_free_space_entry {
702 __le64 offset;
703 __le64 bytes;
704 __u8 type;
705 } __attribute__ ((__packed__));
706
707 struct btrfs_free_space_header {
708 struct btrfs_disk_key location;
709 __le64 generation;
710 __le64 num_entries;
711 __le64 num_bitmaps;
712 } __attribute__ ((__packed__));
713
714 #define BTRFS_HEADER_FLAG_WRITTEN (1ULL << 0)
715 #define BTRFS_HEADER_FLAG_RELOC (1ULL << 1)
716
717 /* Super block flags */
718 /* Errors detected */
719 #define BTRFS_SUPER_FLAG_ERROR (1ULL << 2)
720
721 #define BTRFS_SUPER_FLAG_SEEDING (1ULL << 32)
722 #define BTRFS_SUPER_FLAG_METADUMP (1ULL << 33)
723 #define BTRFS_SUPER_FLAG_METADUMP_V2 (1ULL << 34)
724 #define BTRFS_SUPER_FLAG_CHANGING_FSID (1ULL << 35)
725 #define BTRFS_SUPER_FLAG_CHANGING_FSID_V2 (1ULL << 36)
726
727
728 /*
729 * items in the extent btree are used to record the objectid of the
730 * owner of the block and the number of references
731 */
732
733 struct btrfs_extent_item {
734 __le64 refs;
735 __le64 generation;
736 __le64 flags;
737 } __attribute__ ((__packed__));
738
739 struct btrfs_extent_item_v0 {
740 __le32 refs;
741 } __attribute__ ((__packed__));
742
743
744 #define BTRFS_EXTENT_FLAG_DATA (1ULL << 0)
745 #define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1)
746
747 /* following flags only apply to tree blocks */
748
749 /* use full backrefs for extent pointers in the block */
750 #define BTRFS_BLOCK_FLAG_FULL_BACKREF (1ULL << 8)
751
752 #define BTRFS_BACKREF_REV_MAX 256
753 #define BTRFS_BACKREF_REV_SHIFT 56
754 #define BTRFS_BACKREF_REV_MASK (((u64)BTRFS_BACKREF_REV_MAX - 1) << \
755 BTRFS_BACKREF_REV_SHIFT)
756
757 #define BTRFS_OLD_BACKREF_REV 0
758 #define BTRFS_MIXED_BACKREF_REV 1
759
760 /*
761 * this flag is only used internally by scrub and may be changed at any time
762 * it is only declared here to avoid collisions
763 */
764 #define BTRFS_EXTENT_FLAG_SUPER (1ULL << 48)
765
766 struct btrfs_tree_block_info {
767 struct btrfs_disk_key key;
768 __u8 level;
769 } __attribute__ ((__packed__));
770
771 struct btrfs_extent_data_ref {
772 __le64 root;
773 __le64 objectid;
774 __le64 offset;
775 __le32 count;
776 } __attribute__ ((__packed__));
777
778 struct btrfs_shared_data_ref {
779 __le32 count;
780 } __attribute__ ((__packed__));
781
782 struct btrfs_extent_inline_ref {
783 __u8 type;
784 __le64 offset;
785 } __attribute__ ((__packed__));
786
787 /* dev extents record free space on individual devices. The owner
788 * field points back to the chunk allocation mapping tree that allocated
789 * the extent. The chunk tree uuid field is a way to double check the owner
790 */
791 struct btrfs_dev_extent {
792 __le64 chunk_tree;
793 __le64 chunk_objectid;
794 __le64 chunk_offset;
795 __le64 length;
796 __u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
797 } __attribute__ ((__packed__));
798
799 struct btrfs_inode_ref {
800 __le64 index;
801 __le16 name_len;
802 /* name goes here */
803 } __attribute__ ((__packed__));
804
805 struct btrfs_inode_extref {
806 __le64 parent_objectid;
807 __le64 index;
808 __le16 name_len;
809 __u8 name[];
810 /* name goes here */
811 } __attribute__ ((__packed__));
812
813 struct btrfs_timespec {
814 __le64 sec;
815 __le32 nsec;
816 } __attribute__ ((__packed__));
817
818 struct btrfs_inode_item {
819 /* nfs style generation number */
820 __le64 generation;
821 /* transid that last touched this inode */
822 __le64 transid;
823 __le64 size;
824 __le64 nbytes;
825 __le64 block_group;
826 __le32 nlink;
827 __le32 uid;
828 __le32 gid;
829 __le32 mode;
830 __le64 rdev;
831 __le64 flags;
832
833 /* modification sequence number for NFS */
834 __le64 sequence;
835
836 /*
837 * a little future expansion, for more than this we can
838 * just grow the inode item and version it
839 */
840 __le64 reserved[4];
841 struct btrfs_timespec atime;
842 struct btrfs_timespec ctime;
843 struct btrfs_timespec mtime;
844 struct btrfs_timespec otime;
845 } __attribute__ ((__packed__));
846
847 struct btrfs_dir_log_item {
848 __le64 end;
849 } __attribute__ ((__packed__));
850
851 struct btrfs_dir_item {
852 struct btrfs_disk_key location;
853 __le64 transid;
854 __le16 data_len;
855 __le16 name_len;
856 __u8 type;
857 } __attribute__ ((__packed__));
858
859 #define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
860
861 /*
862 * Internal in-memory flag that a subvolume has been marked for deletion but
863 * still visible as a directory
864 */
865 #define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48)
866
867 struct btrfs_root_item {
868 struct btrfs_inode_item inode;
869 __le64 generation;
870 __le64 root_dirid;
871 __le64 bytenr;
872 __le64 byte_limit;
873 __le64 bytes_used;
874 __le64 last_snapshot;
875 __le64 flags;
876 __le32 refs;
877 struct btrfs_disk_key drop_progress;
878 __u8 drop_level;
879 __u8 level;
880
881 /*
882 * The following fields appear after subvol_uuids+subvol_times
883 * were introduced.
884 */
885
886 /*
887 * This generation number is used to test if the new fields are valid
888 * and up to date while reading the root item. Every time the root item
889 * is written out, the "generation" field is copied into this field. If
890 * anyone ever mounted the fs with an older kernel, we will have
891 * mismatching generation values here and thus must invalidate the
892 * new fields. See btrfs_update_root and btrfs_find_last_root for
893 * details.
894 * the offset of generation_v2 is also used as the start for the memset
895 * when invalidating the fields.
896 */
897 __le64 generation_v2;
898 __u8 uuid[BTRFS_UUID_SIZE];
899 __u8 parent_uuid[BTRFS_UUID_SIZE];
900 __u8 received_uuid[BTRFS_UUID_SIZE];
901 __le64 ctransid; /* updated when an inode changes */
902 __le64 otransid; /* trans when created */
903 __le64 stransid; /* trans when sent. non-zero for received subvol */
904 __le64 rtransid; /* trans when received. non-zero for received subvol */
905 struct btrfs_timespec ctime;
906 struct btrfs_timespec otime;
907 struct btrfs_timespec stime;
908 struct btrfs_timespec rtime;
909 __le64 reserved[8]; /* for future */
910 } __attribute__ ((__packed__));
911
912 /*
913 * Btrfs root item used to be smaller than current size. The old format ends
914 * at where member generation_v2 is.
915 */
916 static __inline__ __u32 btrfs_legacy_root_item_size(void)
917 {
918 return offsetof(struct btrfs_root_item, generation_v2);
919 }
920
921 /*
922 * this is used for both forward and backward root refs
923 */
924 struct btrfs_root_ref {
925 __le64 dirid;
926 __le64 sequence;
927 __le16 name_len;
928 } __attribute__ ((__packed__));
929
930 struct btrfs_disk_balance_args {
931 /*
932 * profiles to operate on, single is denoted by
933 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
934 */
935 __le64 profiles;
936
937 /*
938 * usage filter
939 * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N'
940 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
941 */
942 union {
943 __le64 usage;
944 struct {
945 __le32 usage_min;
946 __le32 usage_max;
947 };
948 };
949
950 /* devid filter */
951 __le64 devid;
952
953 /* devid subset filter [pstart..pend) */
954 __le64 pstart;
955 __le64 pend;
956
957 /* btrfs virtual address space subset filter [vstart..vend) */
958 __le64 vstart;
959 __le64 vend;
960
961 /*
962 * profile to convert to, single is denoted by
963 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
964 */
965 __le64 target;
966
967 /* BTRFS_BALANCE_ARGS_* */
968 __le64 flags;
969
970 /*
971 * BTRFS_BALANCE_ARGS_LIMIT with value 'limit'
972 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum
973 * and maximum
974 */
975 union {
976 __le64 limit;
977 struct {
978 __le32 limit_min;
979 __le32 limit_max;
980 };
981 };
982
983 /*
984 * Process chunks that cross stripes_min..stripes_max devices,
985 * BTRFS_BALANCE_ARGS_STRIPES_RANGE
986 */
987 __le32 stripes_min;
988 __le32 stripes_max;
989
990 __le64 unused[6];
991 } __attribute__ ((__packed__));
992
993 /*
994 * store balance parameters to disk so that balance can be properly
995 * resumed after crash or unmount
996 */
997 struct btrfs_balance_item {
998 /* BTRFS_BALANCE_* */
999 __le64 flags;
1000
1001 struct btrfs_disk_balance_args data;
1002 struct btrfs_disk_balance_args meta;
1003 struct btrfs_disk_balance_args sys;
1004
1005 __le64 unused[4];
1006 } __attribute__ ((__packed__));
1007
1008 enum {
1009 BTRFS_FILE_EXTENT_INLINE = 0,
1010 BTRFS_FILE_EXTENT_REG = 1,
1011 BTRFS_FILE_EXTENT_PREALLOC = 2,
1012 BTRFS_NR_FILE_EXTENT_TYPES = 3,
1013 };
1014
1015 struct btrfs_file_extent_item {
1016 /*
1017 * transaction id that created this extent
1018 */
1019 __le64 generation;
1020 /*
1021 * max number of bytes to hold this extent in ram
1022 * when we split a compressed extent we can't know how big
1023 * each of the resulting pieces will be. So, this is
1024 * an upper limit on the size of the extent in ram instead of
1025 * an exact limit.
1026 */
1027 __le64 ram_bytes;
1028
1029 /*
1030 * 32 bits for the various ways we might encode the data,
1031 * including compression and encryption. If any of these
1032 * are set to something a given disk format doesn't understand
1033 * it is treated like an incompat flag for reading and writing,
1034 * but not for stat.
1035 */
1036 __u8 compression;
1037 __u8 encryption;
1038 __le16 other_encoding; /* spare for later use */
1039
1040 /* are we __inline__ data or a real extent? */
1041 __u8 type;
1042
1043 /*
1044 * disk space consumed by the extent, checksum blocks are included
1045 * in these numbers
1046 *
1047 * At this offset in the structure, the __inline__ extent data start.
1048 */
1049 __le64 disk_bytenr;
1050 __le64 disk_num_bytes;
1051 /*
1052 * the logical offset in file blocks (no csums)
1053 * this extent record is for. This allows a file extent to point
1054 * into the middle of an existing extent on disk, sharing it
1055 * between two snapshots (useful if some bytes in the middle of the
1056 * extent have changed
1057 */
1058 __le64 offset;
1059 /*
1060 * the logical number of file blocks (no csums included). This
1061 * always reflects the size uncompressed and without encoding.
1062 */
1063 __le64 num_bytes;
1064
1065 } __attribute__ ((__packed__));
1066
1067 struct btrfs_csum_item {
1068 __u8 csum;
1069 } __attribute__ ((__packed__));
1070
1071 struct btrfs_dev_stats_item {
1072 /*
1073 * grow this item struct at the end for future enhancements and keep
1074 * the existing values unchanged
1075 */
1076 __le64 values[BTRFS_DEV_STAT_VALUES_MAX];
1077 } __attribute__ ((__packed__));
1078
1079 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS 0
1080 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID 1
1081
1082 struct btrfs_dev_replace_item {
1083 /*
1084 * grow this item struct at the end for future enhancements and keep
1085 * the existing values unchanged
1086 */
1087 __le64 src_devid;
1088 __le64 cursor_left;
1089 __le64 cursor_right;
1090 __le64 cont_reading_from_srcdev_mode;
1091
1092 __le64 replace_state;
1093 __le64 time_started;
1094 __le64 time_stopped;
1095 __le64 num_write_errors;
1096 __le64 num_uncorrectable_read_errors;
1097 } __attribute__ ((__packed__));
1098
1099 /* different types of block groups (and chunks) */
1100 #define BTRFS_BLOCK_GROUP_DATA (1ULL << 0)
1101 #define BTRFS_BLOCK_GROUP_SYSTEM (1ULL << 1)
1102 #define BTRFS_BLOCK_GROUP_METADATA (1ULL << 2)
1103 #define BTRFS_BLOCK_GROUP_RAID0 (1ULL << 3)
1104 #define BTRFS_BLOCK_GROUP_RAID1 (1ULL << 4)
1105 #define BTRFS_BLOCK_GROUP_DUP (1ULL << 5)
1106 #define BTRFS_BLOCK_GROUP_RAID10 (1ULL << 6)
1107 #define BTRFS_BLOCK_GROUP_RAID5 (1ULL << 7)
1108 #define BTRFS_BLOCK_GROUP_RAID6 (1ULL << 8)
1109 #define BTRFS_BLOCK_GROUP_RAID1C3 (1ULL << 9)
1110 #define BTRFS_BLOCK_GROUP_RAID1C4 (1ULL << 10)
1111 #define BTRFS_BLOCK_GROUP_RESERVED (BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
1112 BTRFS_SPACE_INFO_GLOBAL_RSV)
1113
1114 #define BTRFS_BLOCK_GROUP_TYPE_MASK (BTRFS_BLOCK_GROUP_DATA | \
1115 BTRFS_BLOCK_GROUP_SYSTEM | \
1116 BTRFS_BLOCK_GROUP_METADATA)
1117
1118 #define BTRFS_BLOCK_GROUP_PROFILE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \
1119 BTRFS_BLOCK_GROUP_RAID1 | \
1120 BTRFS_BLOCK_GROUP_RAID1C3 | \
1121 BTRFS_BLOCK_GROUP_RAID1C4 | \
1122 BTRFS_BLOCK_GROUP_RAID5 | \
1123 BTRFS_BLOCK_GROUP_RAID6 | \
1124 BTRFS_BLOCK_GROUP_DUP | \
1125 BTRFS_BLOCK_GROUP_RAID10)
1126 #define BTRFS_BLOCK_GROUP_RAID56_MASK (BTRFS_BLOCK_GROUP_RAID5 | \
1127 BTRFS_BLOCK_GROUP_RAID6)
1128
1129 #define BTRFS_BLOCK_GROUP_RAID1_MASK (BTRFS_BLOCK_GROUP_RAID1 | \
1130 BTRFS_BLOCK_GROUP_RAID1C3 | \
1131 BTRFS_BLOCK_GROUP_RAID1C4)
1132
1133 /*
1134 * We need a bit for restriper to be able to tell when chunks of type
1135 * SINGLE are available. This "extended" profile format is used in
1136 * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
1137 * (on-disk). The corresponding on-disk bit in chunk.type is reserved
1138 * to avoid remappings between two formats in future.
1139 */
1140 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE (1ULL << 48)
1141
1142 /*
1143 * A fake block group type that is used to communicate global block reserve
1144 * size to userspace via the SPACE_INFO ioctl.
1145 */
1146 #define BTRFS_SPACE_INFO_GLOBAL_RSV (1ULL << 49)
1147
1148 #define BTRFS_EXTENDED_PROFILE_MASK (BTRFS_BLOCK_GROUP_PROFILE_MASK | \
1149 BTRFS_AVAIL_ALLOC_BIT_SINGLE)
1150
1151 static __inline__ __u64 chunk_to_extended(__u64 flags)
1152 {
1153 if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0)
1154 flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE;
1155
1156 return flags;
1157 }
1158 static __inline__ __u64 extended_to_chunk(__u64 flags)
1159 {
1160 return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
1161 }
1162
1163 struct btrfs_block_group_item {
1164 __le64 used;
1165 __le64 chunk_objectid;
1166 __le64 flags;
1167 } __attribute__ ((__packed__));
1168
1169 struct btrfs_free_space_info {
1170 __le32 extent_count;
1171 __le32 flags;
1172 } __attribute__ ((__packed__));
1173
1174 #define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0)
1175
1176 #define BTRFS_QGROUP_LEVEL_SHIFT 48
1177 static __inline__ __u16 btrfs_qgroup_level(__u64 qgroupid)
1178 {
1179 return (__u16)(qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT);
1180 }
1181
1182 /*
1183 * is subvolume quota turned on?
1184 */
1185 #define BTRFS_QGROUP_STATUS_FLAG_ON (1ULL << 0)
1186 /*
1187 * RESCAN is set during the initialization phase
1188 */
1189 #define BTRFS_QGROUP_STATUS_FLAG_RESCAN (1ULL << 1)
1190 /*
1191 * Some qgroup entries are known to be out of date,
1192 * either because the configuration has changed in a way that
1193 * makes a rescan necessary, or because the fs has been mounted
1194 * with a non-qgroup-aware version.
1195 * Turning qouta off and on again makes it inconsistent, too.
1196 */
1197 #define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT (1ULL << 2)
1198
1199 #define BTRFS_QGROUP_STATUS_FLAGS_MASK (BTRFS_QGROUP_STATUS_FLAG_ON | \
1200 BTRFS_QGROUP_STATUS_FLAG_RESCAN | \
1201 BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT)
1202
1203 #define BTRFS_QGROUP_STATUS_VERSION 1
1204
1205 struct btrfs_qgroup_status_item {
1206 __le64 version;
1207 /*
1208 * the generation is updated during every commit. As older
1209 * versions of btrfs are not aware of qgroups, it will be
1210 * possible to detect inconsistencies by checking the
1211 * generation on mount time
1212 */
1213 __le64 generation;
1214
1215 /* flag definitions see above */
1216 __le64 flags;
1217
1218 /*
1219 * only used during scanning to record the progress
1220 * of the scan. It contains a logical address
1221 */
1222 __le64 rescan;
1223 } __attribute__ ((__packed__));
1224
1225 struct btrfs_qgroup_info_item {
1226 __le64 generation;
1227 __le64 rfer;
1228 __le64 rfer_cmpr;
1229 __le64 excl;
1230 __le64 excl_cmpr;
1231 } __attribute__ ((__packed__));
1232
1233 struct btrfs_qgroup_limit_item {
1234 /*
1235 * only updated when any of the other values change
1236 */
1237 __le64 flags;
1238 __le64 max_rfer;
1239 __le64 max_excl;
1240 __le64 rsv_rfer;
1241 __le64 rsv_excl;
1242 } __attribute__ ((__packed__));
1243
1244 struct btrfs_verity_descriptor_item {
1245 /* Size of the verity descriptor in bytes */
1246 __le64 size;
1247 /*
1248 * When we implement support for fscrypt, we will need to encrypt the
1249 * Merkle tree for encrypted verity files. These 128 bits are for the
1250 * eventual storage of an fscrypt initialization vector.
1251 */
1252 __le64 reserved[2];
1253 __u8 encryption;
1254 } __attribute__ ((__packed__));
1255
1256 #endif /* _BTRFS_CTREE_H_ */
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