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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 #ifdef __KERNEL__
8 #include <linux/stddef.h>
9 #else
10 #include <stddef.h>
11 #endif
12 
13 /*
14  * This header contains the structure definitions and constants used
15  * by file system objects that can be retrieved using
16  * the BTRFS_IOC_SEARCH_TREE ioctl.  That means basically anything that
17  * is needed to describe a leaf node's key or item contents.
18  */
19 
20 /* holds pointers to all of the tree roots */
21 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
22 
23 /* stores information about which extents are in use, and reference counts */
24 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL
25 
26 /*
27  * chunk tree stores translations from logical -> physical block numbering
28  * the super block points to the chunk tree
29  */
30 #define BTRFS_CHUNK_TREE_OBJECTID 3ULL
31 
32 /*
33  * stores information about which areas of a given device are in use.
34  * one per device.  The tree of tree roots points to the device tree
35  */
36 #define BTRFS_DEV_TREE_OBJECTID 4ULL
37 
38 /* one per subvolume, storing files and directories */
39 #define BTRFS_FS_TREE_OBJECTID 5ULL
40 
41 /* directory objectid inside the root tree */
42 #define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
43 
44 /* holds checksums of all the data extents */
45 #define BTRFS_CSUM_TREE_OBJECTID 7ULL
46 
47 /* holds quota configuration and tracking */
48 #define BTRFS_QUOTA_TREE_OBJECTID 8ULL
49 
50 /* for storing items that use the BTRFS_UUID_KEY* types */
51 #define BTRFS_UUID_TREE_OBJECTID 9ULL
52 
53 /* tracks free space in block groups. */
54 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
55 
56 /* device stats in the device tree */
57 #define BTRFS_DEV_STATS_OBJECTID 0ULL
58 
59 /* for storing balance parameters in the root tree */
60 #define BTRFS_BALANCE_OBJECTID -4ULL
61 
62 /* orphan objectid for tracking unlinked/truncated files */
63 #define BTRFS_ORPHAN_OBJECTID -5ULL
64 
65 /* does write ahead logging to speed up fsyncs */
66 #define BTRFS_TREE_LOG_OBJECTID -6ULL
67 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
68 
69 /* for space balancing */
70 #define BTRFS_TREE_RELOC_OBJECTID -8ULL
71 #define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
72 
73 /*
74  * extent checksums all have this objectid
75  * this allows them to share the logging tree
76  * for fsyncs
77  */
78 #define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
79 
80 /* For storing free space cache */
81 #define BTRFS_FREE_SPACE_OBJECTID -11ULL
82 
83 /*
84  * The inode number assigned to the special inode for storing
85  * free ino cache
86  */
87 #define BTRFS_FREE_INO_OBJECTID -12ULL
88 
89 /* dummy objectid represents multiple objectids */
90 #define BTRFS_MULTIPLE_OBJECTIDS -255ULL
91 
92 /*
93  * All files have objectids in this range.
94  */
95 #define BTRFS_FIRST_FREE_OBJECTID 256ULL
96 #define BTRFS_LAST_FREE_OBJECTID -256ULL
97 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
98 
99 
100 /*
101  * the device items go into the chunk tree.  The key is in the form
102  * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
103  */
104 #define BTRFS_DEV_ITEMS_OBJECTID 1ULL
105 
106 #define BTRFS_BTREE_INODE_OBJECTID 1
107 
108 #define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
109 
110 #define BTRFS_DEV_REPLACE_DEVID 0ULL
111 
112 /*
113  * inode items have the data typically returned from stat and store other
114  * info about object characteristics.  There is one for every file and dir in
115  * the FS
116  */
117 #define BTRFS_INODE_ITEM_KEY		1
118 #define BTRFS_INODE_REF_KEY		12
119 #define BTRFS_INODE_EXTREF_KEY		13
120 #define BTRFS_XATTR_ITEM_KEY		24
121 
122 /*
123  * fs verity items are stored under two different key types on disk.
124  * The descriptor items:
125  * [ inode objectid, BTRFS_VERITY_DESC_ITEM_KEY, offset ]
126  *
127  * At offset 0, we store a btrfs_verity_descriptor_item which tracks the size
128  * of the descriptor item and some extra data for encryption.
129  * Starting at offset 1, these hold the generic fs verity descriptor.  The
130  * latter are opaque to btrfs, we just read and write them as a blob for the
131  * higher level verity code.  The most common descriptor size is 256 bytes.
132  *
133  * The merkle tree items:
134  * [ inode objectid, BTRFS_VERITY_MERKLE_ITEM_KEY, offset ]
135  *
136  * These also start at offset 0, and correspond to the merkle tree bytes.  When
137  * fsverity asks for page 0 of the merkle tree, we pull up one page starting at
138  * offset 0 for this key type.  These are also opaque to btrfs, we're blindly
139  * storing whatever fsverity sends down.
140  */
141 #define BTRFS_VERITY_DESC_ITEM_KEY	36
142 #define BTRFS_VERITY_MERKLE_ITEM_KEY	37
143 
144 #define BTRFS_ORPHAN_ITEM_KEY		48
145 /* reserve 2-15 close to the inode for later flexibility */
146 
147 /*
148  * dir items are the name -> inode pointers in a directory.  There is one
149  * for every name in a directory.  BTRFS_DIR_LOG_ITEM_KEY is no longer used
150  * but it's still defined here for documentation purposes and to help avoid
151  * having its numerical value reused in the future.
152  */
153 #define BTRFS_DIR_LOG_ITEM_KEY  60
154 #define BTRFS_DIR_LOG_INDEX_KEY 72
155 #define BTRFS_DIR_ITEM_KEY	84
156 #define BTRFS_DIR_INDEX_KEY	96
157 /*
158  * extent data is for file data
159  */
160 #define BTRFS_EXTENT_DATA_KEY	108
161 
162 /*
163  * extent csums are stored in a separate tree and hold csums for
164  * an entire extent on disk.
165  */
166 #define BTRFS_EXTENT_CSUM_KEY	128
167 
168 /*
169  * root items point to tree roots.  They are typically in the root
170  * tree used by the super block to find all the other trees
171  */
172 #define BTRFS_ROOT_ITEM_KEY	132
173 
174 /*
175  * root backrefs tie subvols and snapshots to the directory entries that
176  * reference them
177  */
178 #define BTRFS_ROOT_BACKREF_KEY	144
179 
180 /*
181  * root refs make a fast index for listing all of the snapshots and
182  * subvolumes referenced by a given root.  They point directly to the
183  * directory item in the root that references the subvol
184  */
185 #define BTRFS_ROOT_REF_KEY	156
186 
187 /*
188  * extent items are in the extent map tree.  These record which blocks
189  * are used, and how many references there are to each block
190  */
191 #define BTRFS_EXTENT_ITEM_KEY	168
192 
193 /*
194  * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
195  * the length, so we save the level in key->offset instead of the length.
196  */
197 #define BTRFS_METADATA_ITEM_KEY	169
198 
199 #define BTRFS_TREE_BLOCK_REF_KEY	176
200 
201 #define BTRFS_EXTENT_DATA_REF_KEY	178
202 
203 #define BTRFS_EXTENT_REF_V0_KEY		180
204 
205 #define BTRFS_SHARED_BLOCK_REF_KEY	182
206 
207 #define BTRFS_SHARED_DATA_REF_KEY	184
208 
209 /*
210  * block groups give us hints into the extent allocation trees.  Which
211  * blocks are free etc etc
212  */
213 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192
214 
215 /*
216  * Every block group is represented in the free space tree by a free space info
217  * item, which stores some accounting information. It is keyed on
218  * (block_group_start, FREE_SPACE_INFO, block_group_length).
219  */
220 #define BTRFS_FREE_SPACE_INFO_KEY 198
221 
222 /*
223  * A free space extent tracks an extent of space that is free in a block group.
224  * It is keyed on (start, FREE_SPACE_EXTENT, length).
225  */
226 #define BTRFS_FREE_SPACE_EXTENT_KEY 199
227 
228 /*
229  * When a block group becomes very fragmented, we convert it to use bitmaps
230  * instead of extents. A free space bitmap is keyed on
231  * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with
232  * (length / sectorsize) bits.
233  */
234 #define BTRFS_FREE_SPACE_BITMAP_KEY 200
235 
236 #define BTRFS_DEV_EXTENT_KEY	204
237 #define BTRFS_DEV_ITEM_KEY	216
238 #define BTRFS_CHUNK_ITEM_KEY	228
239 
240 /*
241  * Records the overall state of the qgroups.
242  * There's only one instance of this key present,
243  * (0, BTRFS_QGROUP_STATUS_KEY, 0)
244  */
245 #define BTRFS_QGROUP_STATUS_KEY         240
246 /*
247  * Records the currently used space of the qgroup.
248  * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
249  */
250 #define BTRFS_QGROUP_INFO_KEY           242
251 /*
252  * Contains the user configured limits for the qgroup.
253  * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
254  */
255 #define BTRFS_QGROUP_LIMIT_KEY          244
256 /*
257  * Records the child-parent relationship of qgroups. For
258  * each relation, 2 keys are present:
259  * (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
260  * (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
261  */
262 #define BTRFS_QGROUP_RELATION_KEY       246
263 
264 /*
265  * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
266  */
267 #define BTRFS_BALANCE_ITEM_KEY	248
268 
269 /*
270  * The key type for tree items that are stored persistently, but do not need to
271  * exist for extended period of time. The items can exist in any tree.
272  *
273  * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
274  *
275  * Existing items:
276  *
277  * - balance status item
278  *   (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
279  */
280 #define BTRFS_TEMPORARY_ITEM_KEY	248
281 
282 /*
283  * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY
284  */
285 #define BTRFS_DEV_STATS_KEY		249
286 
287 /*
288  * The key type for tree items that are stored persistently and usually exist
289  * for a long period, eg. filesystem lifetime. The item kinds can be status
290  * information, stats or preference values. The item can exist in any tree.
291  *
292  * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
293  *
294  * Existing items:
295  *
296  * - device statistics, store IO stats in the device tree, one key for all
297  *   stats
298  *   (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
299  */
300 #define BTRFS_PERSISTENT_ITEM_KEY	249
301 
302 /*
303  * Persistently stores the device replace state in the device tree.
304  * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
305  */
306 #define BTRFS_DEV_REPLACE_KEY	250
307 
308 /*
309  * Stores items that allow to quickly map UUIDs to something else.
310  * These items are part of the filesystem UUID tree.
311  * The key is built like this:
312  * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
313  */
314 #if BTRFS_UUID_SIZE != 16
315 #error "UUID items require BTRFS_UUID_SIZE == 16!"
316 #endif
317 #define BTRFS_UUID_KEY_SUBVOL	251	/* for UUIDs assigned to subvols */
318 #define BTRFS_UUID_KEY_RECEIVED_SUBVOL	252	/* for UUIDs assigned to
319 						 * received subvols */
320 
321 /*
322  * string items are for debugging.  They just store a short string of
323  * data in the FS
324  */
325 #define BTRFS_STRING_ITEM_KEY	253
326 
327 /* Maximum metadata block size (nodesize) */
328 #define BTRFS_MAX_METADATA_BLOCKSIZE			65536
329 
330 /* 32 bytes in various csum fields */
331 #define BTRFS_CSUM_SIZE 32
332 
333 /* csum types */
334 enum btrfs_csum_type {
335 	BTRFS_CSUM_TYPE_CRC32	= 0,
336 	BTRFS_CSUM_TYPE_XXHASH	= 1,
337 	BTRFS_CSUM_TYPE_SHA256	= 2,
338 	BTRFS_CSUM_TYPE_BLAKE2	= 3,
339 };
340 
341 /*
342  * flags definitions for directory entry item type
343  *
344  * Used by:
345  * struct btrfs_dir_item.type
346  *
347  * Values 0..7 must match common file type values in fs_types.h.
348  */
349 #define BTRFS_FT_UNKNOWN	0
350 #define BTRFS_FT_REG_FILE	1
351 #define BTRFS_FT_DIR		2
352 #define BTRFS_FT_CHRDEV		3
353 #define BTRFS_FT_BLKDEV		4
354 #define BTRFS_FT_FIFO		5
355 #define BTRFS_FT_SOCK		6
356 #define BTRFS_FT_SYMLINK	7
357 #define BTRFS_FT_XATTR		8
358 #define BTRFS_FT_MAX		9
359 
360 /*
361  * The key defines the order in the tree, and so it also defines (optimal)
362  * block layout.
363  *
364  * objectid corresponds to the inode number.
365  *
366  * type tells us things about the object, and is a kind of stream selector.
367  * so for a given inode, keys with type of 1 might refer to the inode data,
368  * type of 2 may point to file data in the btree and type == 3 may point to
369  * extents.
370  *
371  * offset is the starting byte offset for this key in the stream.
372  *
373  * btrfs_disk_key is in disk byte order.  struct btrfs_key is always
374  * in cpu native order.  Otherwise they are identical and their sizes
375  * should be the same (ie both packed)
376  */
377 struct btrfs_disk_key {
378 	__le64 objectid;
379 	__u8 type;
380 	__le64 offset;
381 } __attribute__ ((__packed__));
382 
383 struct btrfs_key {
384 	__u64 objectid;
385 	__u8 type;
386 	__u64 offset;
387 } __attribute__ ((__packed__));
388 
389 struct btrfs_dev_item {
390 	/* the internal btrfs device id */
391 	__le64 devid;
392 
393 	/* size of the device */
394 	__le64 total_bytes;
395 
396 	/* bytes used */
397 	__le64 bytes_used;
398 
399 	/* optimal io alignment for this device */
400 	__le32 io_align;
401 
402 	/* optimal io width for this device */
403 	__le32 io_width;
404 
405 	/* minimal io size for this device */
406 	__le32 sector_size;
407 
408 	/* type and info about this device */
409 	__le64 type;
410 
411 	/* expected generation for this device */
412 	__le64 generation;
413 
414 	/*
415 	 * starting byte of this partition on the device,
416 	 * to allow for stripe alignment in the future
417 	 */
418 	__le64 start_offset;
419 
420 	/* grouping information for allocation decisions */
421 	__le32 dev_group;
422 
423 	/* seek speed 0-100 where 100 is fastest */
424 	__u8 seek_speed;
425 
426 	/* bandwidth 0-100 where 100 is fastest */
427 	__u8 bandwidth;
428 
429 	/* btrfs generated uuid for this device */
430 	__u8 uuid[BTRFS_UUID_SIZE];
431 
432 	/* uuid of FS who owns this device */
433 	__u8 fsid[BTRFS_UUID_SIZE];
434 } __attribute__ ((__packed__));
435 
436 struct btrfs_stripe {
437 	__le64 devid;
438 	__le64 offset;
439 	__u8 dev_uuid[BTRFS_UUID_SIZE];
440 } __attribute__ ((__packed__));
441 
442 struct btrfs_chunk {
443 	/* size of this chunk in bytes */
444 	__le64 length;
445 
446 	/* objectid of the root referencing this chunk */
447 	__le64 owner;
448 
449 	__le64 stripe_len;
450 	__le64 type;
451 
452 	/* optimal io alignment for this chunk */
453 	__le32 io_align;
454 
455 	/* optimal io width for this chunk */
456 	__le32 io_width;
457 
458 	/* minimal io size for this chunk */
459 	__le32 sector_size;
460 
461 	/* 2^16 stripes is quite a lot, a second limit is the size of a single
462 	 * item in the btree
463 	 */
464 	__le16 num_stripes;
465 
466 	/* sub stripes only matter for raid10 */
467 	__le16 sub_stripes;
468 	struct btrfs_stripe stripe;
469 	/* additional stripes go here */
470 } __attribute__ ((__packed__));
471 
472 #define BTRFS_FREE_SPACE_EXTENT	1
473 #define BTRFS_FREE_SPACE_BITMAP	2
474 
475 struct btrfs_free_space_entry {
476 	__le64 offset;
477 	__le64 bytes;
478 	__u8 type;
479 } __attribute__ ((__packed__));
480 
481 struct btrfs_free_space_header {
482 	struct btrfs_disk_key location;
483 	__le64 generation;
484 	__le64 num_entries;
485 	__le64 num_bitmaps;
486 } __attribute__ ((__packed__));
487 
488 #define BTRFS_HEADER_FLAG_WRITTEN	(1ULL << 0)
489 #define BTRFS_HEADER_FLAG_RELOC		(1ULL << 1)
490 
491 /* Super block flags */
492 /* Errors detected */
493 #define BTRFS_SUPER_FLAG_ERROR		(1ULL << 2)
494 
495 #define BTRFS_SUPER_FLAG_SEEDING	(1ULL << 32)
496 #define BTRFS_SUPER_FLAG_METADUMP	(1ULL << 33)
497 #define BTRFS_SUPER_FLAG_METADUMP_V2	(1ULL << 34)
498 #define BTRFS_SUPER_FLAG_CHANGING_FSID	(1ULL << 35)
499 #define BTRFS_SUPER_FLAG_CHANGING_FSID_V2 (1ULL << 36)
500 
501 
502 /*
503  * items in the extent btree are used to record the objectid of the
504  * owner of the block and the number of references
505  */
506 
507 struct btrfs_extent_item {
508 	__le64 refs;
509 	__le64 generation;
510 	__le64 flags;
511 } __attribute__ ((__packed__));
512 
513 struct btrfs_extent_item_v0 {
514 	__le32 refs;
515 } __attribute__ ((__packed__));
516 
517 
518 #define BTRFS_EXTENT_FLAG_DATA		(1ULL << 0)
519 #define BTRFS_EXTENT_FLAG_TREE_BLOCK	(1ULL << 1)
520 
521 /* following flags only apply to tree blocks */
522 
523 /* use full backrefs for extent pointers in the block */
524 #define BTRFS_BLOCK_FLAG_FULL_BACKREF	(1ULL << 8)
525 
526 /*
527  * this flag is only used internally by scrub and may be changed at any time
528  * it is only declared here to avoid collisions
529  */
530 #define BTRFS_EXTENT_FLAG_SUPER		(1ULL << 48)
531 
532 struct btrfs_tree_block_info {
533 	struct btrfs_disk_key key;
534 	__u8 level;
535 } __attribute__ ((__packed__));
536 
537 struct btrfs_extent_data_ref {
538 	__le64 root;
539 	__le64 objectid;
540 	__le64 offset;
541 	__le32 count;
542 } __attribute__ ((__packed__));
543 
544 struct btrfs_shared_data_ref {
545 	__le32 count;
546 } __attribute__ ((__packed__));
547 
548 struct btrfs_extent_inline_ref {
549 	__u8 type;
550 	__le64 offset;
551 } __attribute__ ((__packed__));
552 
553 /* dev extents record free space on individual devices.  The owner
554  * field points back to the chunk allocation mapping tree that allocated
555  * the extent.  The chunk tree uuid field is a way to double check the owner
556  */
557 struct btrfs_dev_extent {
558 	__le64 chunk_tree;
559 	__le64 chunk_objectid;
560 	__le64 chunk_offset;
561 	__le64 length;
562 	__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
563 } __attribute__ ((__packed__));
564 
565 struct btrfs_inode_ref {
566 	__le64 index;
567 	__le16 name_len;
568 	/* name goes here */
569 } __attribute__ ((__packed__));
570 
571 struct btrfs_inode_extref {
572 	__le64 parent_objectid;
573 	__le64 index;
574 	__le16 name_len;
575 	__u8   name[0];
576 	/* name goes here */
577 } __attribute__ ((__packed__));
578 
579 struct btrfs_timespec {
580 	__le64 sec;
581 	__le32 nsec;
582 } __attribute__ ((__packed__));
583 
584 struct btrfs_inode_item {
585 	/* nfs style generation number */
586 	__le64 generation;
587 	/* transid that last touched this inode */
588 	__le64 transid;
589 	__le64 size;
590 	__le64 nbytes;
591 	__le64 block_group;
592 	__le32 nlink;
593 	__le32 uid;
594 	__le32 gid;
595 	__le32 mode;
596 	__le64 rdev;
597 	__le64 flags;
598 
599 	/* modification sequence number for NFS */
600 	__le64 sequence;
601 
602 	/*
603 	 * a little future expansion, for more than this we can
604 	 * just grow the inode item and version it
605 	 */
606 	__le64 reserved[4];
607 	struct btrfs_timespec atime;
608 	struct btrfs_timespec ctime;
609 	struct btrfs_timespec mtime;
610 	struct btrfs_timespec otime;
611 } __attribute__ ((__packed__));
612 
613 struct btrfs_dir_log_item {
614 	__le64 end;
615 } __attribute__ ((__packed__));
616 
617 struct btrfs_dir_item {
618 	struct btrfs_disk_key location;
619 	__le64 transid;
620 	__le16 data_len;
621 	__le16 name_len;
622 	__u8 type;
623 } __attribute__ ((__packed__));
624 
625 #define BTRFS_ROOT_SUBVOL_RDONLY	(1ULL << 0)
626 
627 /*
628  * Internal in-memory flag that a subvolume has been marked for deletion but
629  * still visible as a directory
630  */
631 #define BTRFS_ROOT_SUBVOL_DEAD		(1ULL << 48)
632 
633 struct btrfs_root_item {
634 	struct btrfs_inode_item inode;
635 	__le64 generation;
636 	__le64 root_dirid;
637 	__le64 bytenr;
638 	__le64 byte_limit;
639 	__le64 bytes_used;
640 	__le64 last_snapshot;
641 	__le64 flags;
642 	__le32 refs;
643 	struct btrfs_disk_key drop_progress;
644 	__u8 drop_level;
645 	__u8 level;
646 
647 	/*
648 	 * The following fields appear after subvol_uuids+subvol_times
649 	 * were introduced.
650 	 */
651 
652 	/*
653 	 * This generation number is used to test if the new fields are valid
654 	 * and up to date while reading the root item. Every time the root item
655 	 * is written out, the "generation" field is copied into this field. If
656 	 * anyone ever mounted the fs with an older kernel, we will have
657 	 * mismatching generation values here and thus must invalidate the
658 	 * new fields. See btrfs_update_root and btrfs_find_last_root for
659 	 * details.
660 	 * the offset of generation_v2 is also used as the start for the memset
661 	 * when invalidating the fields.
662 	 */
663 	__le64 generation_v2;
664 	__u8 uuid[BTRFS_UUID_SIZE];
665 	__u8 parent_uuid[BTRFS_UUID_SIZE];
666 	__u8 received_uuid[BTRFS_UUID_SIZE];
667 	__le64 ctransid; /* updated when an inode changes */
668 	__le64 otransid; /* trans when created */
669 	__le64 stransid; /* trans when sent. non-zero for received subvol */
670 	__le64 rtransid; /* trans when received. non-zero for received subvol */
671 	struct btrfs_timespec ctime;
672 	struct btrfs_timespec otime;
673 	struct btrfs_timespec stime;
674 	struct btrfs_timespec rtime;
675 	__le64 reserved[8]; /* for future */
676 } __attribute__ ((__packed__));
677 
678 /*
679  * Btrfs root item used to be smaller than current size.  The old format ends
680  * at where member generation_v2 is.
681  */
btrfs_legacy_root_item_size(void)682 static inline __u32 btrfs_legacy_root_item_size(void)
683 {
684 	return offsetof(struct btrfs_root_item, generation_v2);
685 }
686 
687 /*
688  * this is used for both forward and backward root refs
689  */
690 struct btrfs_root_ref {
691 	__le64 dirid;
692 	__le64 sequence;
693 	__le16 name_len;
694 } __attribute__ ((__packed__));
695 
696 struct btrfs_disk_balance_args {
697 	/*
698 	 * profiles to operate on, single is denoted by
699 	 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
700 	 */
701 	__le64 profiles;
702 
703 	/*
704 	 * usage filter
705 	 * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N'
706 	 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
707 	 */
708 	union {
709 		__le64 usage;
710 		struct {
711 			__le32 usage_min;
712 			__le32 usage_max;
713 		};
714 	};
715 
716 	/* devid filter */
717 	__le64 devid;
718 
719 	/* devid subset filter [pstart..pend) */
720 	__le64 pstart;
721 	__le64 pend;
722 
723 	/* btrfs virtual address space subset filter [vstart..vend) */
724 	__le64 vstart;
725 	__le64 vend;
726 
727 	/*
728 	 * profile to convert to, single is denoted by
729 	 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
730 	 */
731 	__le64 target;
732 
733 	/* BTRFS_BALANCE_ARGS_* */
734 	__le64 flags;
735 
736 	/*
737 	 * BTRFS_BALANCE_ARGS_LIMIT with value 'limit'
738 	 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum
739 	 * and maximum
740 	 */
741 	union {
742 		__le64 limit;
743 		struct {
744 			__le32 limit_min;
745 			__le32 limit_max;
746 		};
747 	};
748 
749 	/*
750 	 * Process chunks that cross stripes_min..stripes_max devices,
751 	 * BTRFS_BALANCE_ARGS_STRIPES_RANGE
752 	 */
753 	__le32 stripes_min;
754 	__le32 stripes_max;
755 
756 	__le64 unused[6];
757 } __attribute__ ((__packed__));
758 
759 /*
760  * store balance parameters to disk so that balance can be properly
761  * resumed after crash or unmount
762  */
763 struct btrfs_balance_item {
764 	/* BTRFS_BALANCE_* */
765 	__le64 flags;
766 
767 	struct btrfs_disk_balance_args data;
768 	struct btrfs_disk_balance_args meta;
769 	struct btrfs_disk_balance_args sys;
770 
771 	__le64 unused[4];
772 } __attribute__ ((__packed__));
773 
774 enum {
775 	BTRFS_FILE_EXTENT_INLINE   = 0,
776 	BTRFS_FILE_EXTENT_REG      = 1,
777 	BTRFS_FILE_EXTENT_PREALLOC = 2,
778 	BTRFS_NR_FILE_EXTENT_TYPES = 3,
779 };
780 
781 struct btrfs_file_extent_item {
782 	/*
783 	 * transaction id that created this extent
784 	 */
785 	__le64 generation;
786 	/*
787 	 * max number of bytes to hold this extent in ram
788 	 * when we split a compressed extent we can't know how big
789 	 * each of the resulting pieces will be.  So, this is
790 	 * an upper limit on the size of the extent in ram instead of
791 	 * an exact limit.
792 	 */
793 	__le64 ram_bytes;
794 
795 	/*
796 	 * 32 bits for the various ways we might encode the data,
797 	 * including compression and encryption.  If any of these
798 	 * are set to something a given disk format doesn't understand
799 	 * it is treated like an incompat flag for reading and writing,
800 	 * but not for stat.
801 	 */
802 	__u8 compression;
803 	__u8 encryption;
804 	__le16 other_encoding; /* spare for later use */
805 
806 	/* are we inline data or a real extent? */
807 	__u8 type;
808 
809 	/*
810 	 * disk space consumed by the extent, checksum blocks are included
811 	 * in these numbers
812 	 *
813 	 * At this offset in the structure, the inline extent data start.
814 	 */
815 	__le64 disk_bytenr;
816 	__le64 disk_num_bytes;
817 	/*
818 	 * the logical offset in file blocks (no csums)
819 	 * this extent record is for.  This allows a file extent to point
820 	 * into the middle of an existing extent on disk, sharing it
821 	 * between two snapshots (useful if some bytes in the middle of the
822 	 * extent have changed
823 	 */
824 	__le64 offset;
825 	/*
826 	 * the logical number of file blocks (no csums included).  This
827 	 * always reflects the size uncompressed and without encoding.
828 	 */
829 	__le64 num_bytes;
830 
831 } __attribute__ ((__packed__));
832 
833 struct btrfs_csum_item {
834 	__u8 csum;
835 } __attribute__ ((__packed__));
836 
837 struct btrfs_dev_stats_item {
838 	/*
839 	 * grow this item struct at the end for future enhancements and keep
840 	 * the existing values unchanged
841 	 */
842 	__le64 values[BTRFS_DEV_STAT_VALUES_MAX];
843 } __attribute__ ((__packed__));
844 
845 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS	0
846 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID	1
847 
848 struct btrfs_dev_replace_item {
849 	/*
850 	 * grow this item struct at the end for future enhancements and keep
851 	 * the existing values unchanged
852 	 */
853 	__le64 src_devid;
854 	__le64 cursor_left;
855 	__le64 cursor_right;
856 	__le64 cont_reading_from_srcdev_mode;
857 
858 	__le64 replace_state;
859 	__le64 time_started;
860 	__le64 time_stopped;
861 	__le64 num_write_errors;
862 	__le64 num_uncorrectable_read_errors;
863 } __attribute__ ((__packed__));
864 
865 /* different types of block groups (and chunks) */
866 #define BTRFS_BLOCK_GROUP_DATA		(1ULL << 0)
867 #define BTRFS_BLOCK_GROUP_SYSTEM	(1ULL << 1)
868 #define BTRFS_BLOCK_GROUP_METADATA	(1ULL << 2)
869 #define BTRFS_BLOCK_GROUP_RAID0		(1ULL << 3)
870 #define BTRFS_BLOCK_GROUP_RAID1		(1ULL << 4)
871 #define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)
872 #define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)
873 #define BTRFS_BLOCK_GROUP_RAID5         (1ULL << 7)
874 #define BTRFS_BLOCK_GROUP_RAID6         (1ULL << 8)
875 #define BTRFS_BLOCK_GROUP_RAID1C3       (1ULL << 9)
876 #define BTRFS_BLOCK_GROUP_RAID1C4       (1ULL << 10)
877 #define BTRFS_BLOCK_GROUP_RESERVED	(BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
878 					 BTRFS_SPACE_INFO_GLOBAL_RSV)
879 
880 enum btrfs_raid_types {
881 	BTRFS_RAID_RAID10,
882 	BTRFS_RAID_RAID1,
883 	BTRFS_RAID_DUP,
884 	BTRFS_RAID_RAID0,
885 	BTRFS_RAID_SINGLE,
886 	BTRFS_RAID_RAID5,
887 	BTRFS_RAID_RAID6,
888 	BTRFS_RAID_RAID1C3,
889 	BTRFS_RAID_RAID1C4,
890 	BTRFS_NR_RAID_TYPES
891 };
892 
893 #define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
894 					 BTRFS_BLOCK_GROUP_SYSTEM |  \
895 					 BTRFS_BLOCK_GROUP_METADATA)
896 
897 #define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
898 					 BTRFS_BLOCK_GROUP_RAID1 |   \
899 					 BTRFS_BLOCK_GROUP_RAID1C3 | \
900 					 BTRFS_BLOCK_GROUP_RAID1C4 | \
901 					 BTRFS_BLOCK_GROUP_RAID5 |   \
902 					 BTRFS_BLOCK_GROUP_RAID6 |   \
903 					 BTRFS_BLOCK_GROUP_DUP |     \
904 					 BTRFS_BLOCK_GROUP_RAID10)
905 #define BTRFS_BLOCK_GROUP_RAID56_MASK	(BTRFS_BLOCK_GROUP_RAID5 |   \
906 					 BTRFS_BLOCK_GROUP_RAID6)
907 
908 #define BTRFS_BLOCK_GROUP_RAID1_MASK	(BTRFS_BLOCK_GROUP_RAID1 |   \
909 					 BTRFS_BLOCK_GROUP_RAID1C3 | \
910 					 BTRFS_BLOCK_GROUP_RAID1C4)
911 
912 /*
913  * We need a bit for restriper to be able to tell when chunks of type
914  * SINGLE are available.  This "extended" profile format is used in
915  * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
916  * (on-disk).  The corresponding on-disk bit in chunk.type is reserved
917  * to avoid remappings between two formats in future.
918  */
919 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
920 
921 /*
922  * A fake block group type that is used to communicate global block reserve
923  * size to userspace via the SPACE_INFO ioctl.
924  */
925 #define BTRFS_SPACE_INFO_GLOBAL_RSV	(1ULL << 49)
926 
927 #define BTRFS_EXTENDED_PROFILE_MASK	(BTRFS_BLOCK_GROUP_PROFILE_MASK | \
928 					 BTRFS_AVAIL_ALLOC_BIT_SINGLE)
929 
chunk_to_extended(__u64 flags)930 static inline __u64 chunk_to_extended(__u64 flags)
931 {
932 	if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0)
933 		flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE;
934 
935 	return flags;
936 }
extended_to_chunk(__u64 flags)937 static inline __u64 extended_to_chunk(__u64 flags)
938 {
939 	return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
940 }
941 
942 struct btrfs_block_group_item {
943 	__le64 used;
944 	__le64 chunk_objectid;
945 	__le64 flags;
946 } __attribute__ ((__packed__));
947 
948 struct btrfs_free_space_info {
949 	__le32 extent_count;
950 	__le32 flags;
951 } __attribute__ ((__packed__));
952 
953 #define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0)
954 
955 #define BTRFS_QGROUP_LEVEL_SHIFT		48
btrfs_qgroup_level(__u64 qgroupid)956 static inline __u16 btrfs_qgroup_level(__u64 qgroupid)
957 {
958 	return (__u16)(qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT);
959 }
960 
961 /*
962  * is subvolume quota turned on?
963  */
964 #define BTRFS_QGROUP_STATUS_FLAG_ON		(1ULL << 0)
965 /*
966  * RESCAN is set during the initialization phase
967  */
968 #define BTRFS_QGROUP_STATUS_FLAG_RESCAN		(1ULL << 1)
969 /*
970  * Some qgroup entries are known to be out of date,
971  * either because the configuration has changed in a way that
972  * makes a rescan necessary, or because the fs has been mounted
973  * with a non-qgroup-aware version.
974  * Turning qouta off and on again makes it inconsistent, too.
975  */
976 #define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT	(1ULL << 2)
977 
978 #define BTRFS_QGROUP_STATUS_VERSION        1
979 
980 struct btrfs_qgroup_status_item {
981 	__le64 version;
982 	/*
983 	 * the generation is updated during every commit. As older
984 	 * versions of btrfs are not aware of qgroups, it will be
985 	 * possible to detect inconsistencies by checking the
986 	 * generation on mount time
987 	 */
988 	__le64 generation;
989 
990 	/* flag definitions see above */
991 	__le64 flags;
992 
993 	/*
994 	 * only used during scanning to record the progress
995 	 * of the scan. It contains a logical address
996 	 */
997 	__le64 rescan;
998 } __attribute__ ((__packed__));
999 
1000 struct btrfs_qgroup_info_item {
1001 	__le64 generation;
1002 	__le64 rfer;
1003 	__le64 rfer_cmpr;
1004 	__le64 excl;
1005 	__le64 excl_cmpr;
1006 } __attribute__ ((__packed__));
1007 
1008 struct btrfs_qgroup_limit_item {
1009 	/*
1010 	 * only updated when any of the other values change
1011 	 */
1012 	__le64 flags;
1013 	__le64 max_rfer;
1014 	__le64 max_excl;
1015 	__le64 rsv_rfer;
1016 	__le64 rsv_excl;
1017 } __attribute__ ((__packed__));
1018 
1019 struct btrfs_verity_descriptor_item {
1020 	/* Size of the verity descriptor in bytes */
1021 	__le64 size;
1022 	/*
1023 	 * When we implement support for fscrypt, we will need to encrypt the
1024 	 * Merkle tree for encrypted verity files. These 128 bits are for the
1025 	 * eventual storage of an fscrypt initialization vector.
1026 	 */
1027 	__le64 reserved[2];
1028 	__u8 encryption;
1029 } __attribute__ ((__packed__));
1030 
1031 #endif /* _BTRFS_CTREE_H_ */
1032