xref: /linux-6.15/include/uapi/linux/btrfs_tree.h (revision e00a844a)
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 
8 /*
9  * This header contains the structure definitions and constants used
10  * by file system objects that can be retrieved using
11  * the BTRFS_IOC_SEARCH_TREE ioctl.  That means basically anything that
12  * is needed to describe a leaf node's key or item contents.
13  */
14 
15 /* holds pointers to all of the tree roots */
16 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
17 
18 /* stores information about which extents are in use, and reference counts */
19 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL
20 
21 /*
22  * chunk tree stores translations from logical -> physical block numbering
23  * the super block points to the chunk tree
24  */
25 #define BTRFS_CHUNK_TREE_OBJECTID 3ULL
26 
27 /*
28  * stores information about which areas of a given device are in use.
29  * one per device.  The tree of tree roots points to the device tree
30  */
31 #define BTRFS_DEV_TREE_OBJECTID 4ULL
32 
33 /* one per subvolume, storing files and directories */
34 #define BTRFS_FS_TREE_OBJECTID 5ULL
35 
36 /* directory objectid inside the root tree */
37 #define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
38 
39 /* holds checksums of all the data extents */
40 #define BTRFS_CSUM_TREE_OBJECTID 7ULL
41 
42 /* holds quota configuration and tracking */
43 #define BTRFS_QUOTA_TREE_OBJECTID 8ULL
44 
45 /* for storing items that use the BTRFS_UUID_KEY* types */
46 #define BTRFS_UUID_TREE_OBJECTID 9ULL
47 
48 /* tracks free space in block groups. */
49 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
50 
51 /* device stats in the device tree */
52 #define BTRFS_DEV_STATS_OBJECTID 0ULL
53 
54 /* for storing balance parameters in the root tree */
55 #define BTRFS_BALANCE_OBJECTID -4ULL
56 
57 /* orhpan objectid for tracking unlinked/truncated files */
58 #define BTRFS_ORPHAN_OBJECTID -5ULL
59 
60 /* does write ahead logging to speed up fsyncs */
61 #define BTRFS_TREE_LOG_OBJECTID -6ULL
62 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
63 
64 /* for space balancing */
65 #define BTRFS_TREE_RELOC_OBJECTID -8ULL
66 #define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
67 
68 /*
69  * extent checksums all have this objectid
70  * this allows them to share the logging tree
71  * for fsyncs
72  */
73 #define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
74 
75 /* For storing free space cache */
76 #define BTRFS_FREE_SPACE_OBJECTID -11ULL
77 
78 /*
79  * The inode number assigned to the special inode for storing
80  * free ino cache
81  */
82 #define BTRFS_FREE_INO_OBJECTID -12ULL
83 
84 /* dummy objectid represents multiple objectids */
85 #define BTRFS_MULTIPLE_OBJECTIDS -255ULL
86 
87 /*
88  * All files have objectids in this range.
89  */
90 #define BTRFS_FIRST_FREE_OBJECTID 256ULL
91 #define BTRFS_LAST_FREE_OBJECTID -256ULL
92 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
93 
94 
95 /*
96  * the device items go into the chunk tree.  The key is in the form
97  * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
98  */
99 #define BTRFS_DEV_ITEMS_OBJECTID 1ULL
100 
101 #define BTRFS_BTREE_INODE_OBJECTID 1
102 
103 #define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
104 
105 #define BTRFS_DEV_REPLACE_DEVID 0ULL
106 
107 /*
108  * inode items have the data typically returned from stat and store other
109  * info about object characteristics.  There is one for every file and dir in
110  * the FS
111  */
112 #define BTRFS_INODE_ITEM_KEY		1
113 #define BTRFS_INODE_REF_KEY		12
114 #define BTRFS_INODE_EXTREF_KEY		13
115 #define BTRFS_XATTR_ITEM_KEY		24
116 #define BTRFS_ORPHAN_ITEM_KEY		48
117 /* reserve 2-15 close to the inode for later flexibility */
118 
119 /*
120  * dir items are the name -> inode pointers in a directory.  There is one
121  * for every name in a directory.
122  */
123 #define BTRFS_DIR_LOG_ITEM_KEY  60
124 #define BTRFS_DIR_LOG_INDEX_KEY 72
125 #define BTRFS_DIR_ITEM_KEY	84
126 #define BTRFS_DIR_INDEX_KEY	96
127 /*
128  * extent data is for file data
129  */
130 #define BTRFS_EXTENT_DATA_KEY	108
131 
132 /*
133  * extent csums are stored in a separate tree and hold csums for
134  * an entire extent on disk.
135  */
136 #define BTRFS_EXTENT_CSUM_KEY	128
137 
138 /*
139  * root items point to tree roots.  They are typically in the root
140  * tree used by the super block to find all the other trees
141  */
142 #define BTRFS_ROOT_ITEM_KEY	132
143 
144 /*
145  * root backrefs tie subvols and snapshots to the directory entries that
146  * reference them
147  */
148 #define BTRFS_ROOT_BACKREF_KEY	144
149 
150 /*
151  * root refs make a fast index for listing all of the snapshots and
152  * subvolumes referenced by a given root.  They point directly to the
153  * directory item in the root that references the subvol
154  */
155 #define BTRFS_ROOT_REF_KEY	156
156 
157 /*
158  * extent items are in the extent map tree.  These record which blocks
159  * are used, and how many references there are to each block
160  */
161 #define BTRFS_EXTENT_ITEM_KEY	168
162 
163 /*
164  * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
165  * the length, so we save the level in key->offset instead of the length.
166  */
167 #define BTRFS_METADATA_ITEM_KEY	169
168 
169 #define BTRFS_TREE_BLOCK_REF_KEY	176
170 
171 #define BTRFS_EXTENT_DATA_REF_KEY	178
172 
173 #define BTRFS_EXTENT_REF_V0_KEY		180
174 
175 #define BTRFS_SHARED_BLOCK_REF_KEY	182
176 
177 #define BTRFS_SHARED_DATA_REF_KEY	184
178 
179 /*
180  * block groups give us hints into the extent allocation trees.  Which
181  * blocks are free etc etc
182  */
183 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192
184 
185 /*
186  * Every block group is represented in the free space tree by a free space info
187  * item, which stores some accounting information. It is keyed on
188  * (block_group_start, FREE_SPACE_INFO, block_group_length).
189  */
190 #define BTRFS_FREE_SPACE_INFO_KEY 198
191 
192 /*
193  * A free space extent tracks an extent of space that is free in a block group.
194  * It is keyed on (start, FREE_SPACE_EXTENT, length).
195  */
196 #define BTRFS_FREE_SPACE_EXTENT_KEY 199
197 
198 /*
199  * When a block group becomes very fragmented, we convert it to use bitmaps
200  * instead of extents. A free space bitmap is keyed on
201  * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with
202  * (length / sectorsize) bits.
203  */
204 #define BTRFS_FREE_SPACE_BITMAP_KEY 200
205 
206 #define BTRFS_DEV_EXTENT_KEY	204
207 #define BTRFS_DEV_ITEM_KEY	216
208 #define BTRFS_CHUNK_ITEM_KEY	228
209 
210 /*
211  * Records the overall state of the qgroups.
212  * There's only one instance of this key present,
213  * (0, BTRFS_QGROUP_STATUS_KEY, 0)
214  */
215 #define BTRFS_QGROUP_STATUS_KEY         240
216 /*
217  * Records the currently used space of the qgroup.
218  * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
219  */
220 #define BTRFS_QGROUP_INFO_KEY           242
221 /*
222  * Contains the user configured limits for the qgroup.
223  * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
224  */
225 #define BTRFS_QGROUP_LIMIT_KEY          244
226 /*
227  * Records the child-parent relationship of qgroups. For
228  * each relation, 2 keys are present:
229  * (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
230  * (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
231  */
232 #define BTRFS_QGROUP_RELATION_KEY       246
233 
234 /*
235  * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
236  */
237 #define BTRFS_BALANCE_ITEM_KEY	248
238 
239 /*
240  * The key type for tree items that are stored persistently, but do not need to
241  * exist for extended period of time. The items can exist in any tree.
242  *
243  * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
244  *
245  * Existing items:
246  *
247  * - balance status item
248  *   (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
249  */
250 #define BTRFS_TEMPORARY_ITEM_KEY	248
251 
252 /*
253  * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY
254  */
255 #define BTRFS_DEV_STATS_KEY		249
256 
257 /*
258  * The key type for tree items that are stored persistently and usually exist
259  * for a long period, eg. filesystem lifetime. The item kinds can be status
260  * information, stats or preference values. The item can exist in any tree.
261  *
262  * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
263  *
264  * Existing items:
265  *
266  * - device statistics, store IO stats in the device tree, one key for all
267  *   stats
268  *   (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
269  */
270 #define BTRFS_PERSISTENT_ITEM_KEY	249
271 
272 /*
273  * Persistantly stores the device replace state in the device tree.
274  * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
275  */
276 #define BTRFS_DEV_REPLACE_KEY	250
277 
278 /*
279  * Stores items that allow to quickly map UUIDs to something else.
280  * These items are part of the filesystem UUID tree.
281  * The key is built like this:
282  * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
283  */
284 #if BTRFS_UUID_SIZE != 16
285 #error "UUID items require BTRFS_UUID_SIZE == 16!"
286 #endif
287 #define BTRFS_UUID_KEY_SUBVOL	251	/* for UUIDs assigned to subvols */
288 #define BTRFS_UUID_KEY_RECEIVED_SUBVOL	252	/* for UUIDs assigned to
289 						 * received subvols */
290 
291 /*
292  * string items are for debugging.  They just store a short string of
293  * data in the FS
294  */
295 #define BTRFS_STRING_ITEM_KEY	253
296 
297 
298 
299 /* 32 bytes in various csum fields */
300 #define BTRFS_CSUM_SIZE 32
301 
302 /* csum types */
303 #define BTRFS_CSUM_TYPE_CRC32	0
304 
305 /*
306  * flags definitions for directory entry item type
307  *
308  * Used by:
309  * struct btrfs_dir_item.type
310  */
311 #define BTRFS_FT_UNKNOWN	0
312 #define BTRFS_FT_REG_FILE	1
313 #define BTRFS_FT_DIR		2
314 #define BTRFS_FT_CHRDEV		3
315 #define BTRFS_FT_BLKDEV		4
316 #define BTRFS_FT_FIFO		5
317 #define BTRFS_FT_SOCK		6
318 #define BTRFS_FT_SYMLINK	7
319 #define BTRFS_FT_XATTR		8
320 #define BTRFS_FT_MAX		9
321 
322 /*
323  * The key defines the order in the tree, and so it also defines (optimal)
324  * block layout.
325  *
326  * objectid corresponds to the inode number.
327  *
328  * type tells us things about the object, and is a kind of stream selector.
329  * so for a given inode, keys with type of 1 might refer to the inode data,
330  * type of 2 may point to file data in the btree and type == 3 may point to
331  * extents.
332  *
333  * offset is the starting byte offset for this key in the stream.
334  *
335  * btrfs_disk_key is in disk byte order.  struct btrfs_key is always
336  * in cpu native order.  Otherwise they are identical and their sizes
337  * should be the same (ie both packed)
338  */
339 struct btrfs_disk_key {
340 	__le64 objectid;
341 	__u8 type;
342 	__le64 offset;
343 } __attribute__ ((__packed__));
344 
345 struct btrfs_key {
346 	__u64 objectid;
347 	__u8 type;
348 	__u64 offset;
349 } __attribute__ ((__packed__));
350 
351 struct btrfs_dev_item {
352 	/* the internal btrfs device id */
353 	__le64 devid;
354 
355 	/* size of the device */
356 	__le64 total_bytes;
357 
358 	/* bytes used */
359 	__le64 bytes_used;
360 
361 	/* optimal io alignment for this device */
362 	__le32 io_align;
363 
364 	/* optimal io width for this device */
365 	__le32 io_width;
366 
367 	/* minimal io size for this device */
368 	__le32 sector_size;
369 
370 	/* type and info about this device */
371 	__le64 type;
372 
373 	/* expected generation for this device */
374 	__le64 generation;
375 
376 	/*
377 	 * starting byte of this partition on the device,
378 	 * to allow for stripe alignment in the future
379 	 */
380 	__le64 start_offset;
381 
382 	/* grouping information for allocation decisions */
383 	__le32 dev_group;
384 
385 	/* seek speed 0-100 where 100 is fastest */
386 	__u8 seek_speed;
387 
388 	/* bandwidth 0-100 where 100 is fastest */
389 	__u8 bandwidth;
390 
391 	/* btrfs generated uuid for this device */
392 	__u8 uuid[BTRFS_UUID_SIZE];
393 
394 	/* uuid of FS who owns this device */
395 	__u8 fsid[BTRFS_UUID_SIZE];
396 } __attribute__ ((__packed__));
397 
398 struct btrfs_stripe {
399 	__le64 devid;
400 	__le64 offset;
401 	__u8 dev_uuid[BTRFS_UUID_SIZE];
402 } __attribute__ ((__packed__));
403 
404 struct btrfs_chunk {
405 	/* size of this chunk in bytes */
406 	__le64 length;
407 
408 	/* objectid of the root referencing this chunk */
409 	__le64 owner;
410 
411 	__le64 stripe_len;
412 	__le64 type;
413 
414 	/* optimal io alignment for this chunk */
415 	__le32 io_align;
416 
417 	/* optimal io width for this chunk */
418 	__le32 io_width;
419 
420 	/* minimal io size for this chunk */
421 	__le32 sector_size;
422 
423 	/* 2^16 stripes is quite a lot, a second limit is the size of a single
424 	 * item in the btree
425 	 */
426 	__le16 num_stripes;
427 
428 	/* sub stripes only matter for raid10 */
429 	__le16 sub_stripes;
430 	struct btrfs_stripe stripe;
431 	/* additional stripes go here */
432 } __attribute__ ((__packed__));
433 
434 #define BTRFS_FREE_SPACE_EXTENT	1
435 #define BTRFS_FREE_SPACE_BITMAP	2
436 
437 struct btrfs_free_space_entry {
438 	__le64 offset;
439 	__le64 bytes;
440 	__u8 type;
441 } __attribute__ ((__packed__));
442 
443 struct btrfs_free_space_header {
444 	struct btrfs_disk_key location;
445 	__le64 generation;
446 	__le64 num_entries;
447 	__le64 num_bitmaps;
448 } __attribute__ ((__packed__));
449 
450 #define BTRFS_HEADER_FLAG_WRITTEN	(1ULL << 0)
451 #define BTRFS_HEADER_FLAG_RELOC		(1ULL << 1)
452 
453 /* Super block flags */
454 /* Errors detected */
455 #define BTRFS_SUPER_FLAG_ERROR		(1ULL << 2)
456 
457 #define BTRFS_SUPER_FLAG_SEEDING	(1ULL << 32)
458 #define BTRFS_SUPER_FLAG_METADUMP	(1ULL << 33)
459 
460 
461 /*
462  * items in the extent btree are used to record the objectid of the
463  * owner of the block and the number of references
464  */
465 
466 struct btrfs_extent_item {
467 	__le64 refs;
468 	__le64 generation;
469 	__le64 flags;
470 } __attribute__ ((__packed__));
471 
472 struct btrfs_extent_item_v0 {
473 	__le32 refs;
474 } __attribute__ ((__packed__));
475 
476 
477 #define BTRFS_EXTENT_FLAG_DATA		(1ULL << 0)
478 #define BTRFS_EXTENT_FLAG_TREE_BLOCK	(1ULL << 1)
479 
480 /* following flags only apply to tree blocks */
481 
482 /* use full backrefs for extent pointers in the block */
483 #define BTRFS_BLOCK_FLAG_FULL_BACKREF	(1ULL << 8)
484 
485 /*
486  * this flag is only used internally by scrub and may be changed at any time
487  * it is only declared here to avoid collisions
488  */
489 #define BTRFS_EXTENT_FLAG_SUPER		(1ULL << 48)
490 
491 struct btrfs_tree_block_info {
492 	struct btrfs_disk_key key;
493 	__u8 level;
494 } __attribute__ ((__packed__));
495 
496 struct btrfs_extent_data_ref {
497 	__le64 root;
498 	__le64 objectid;
499 	__le64 offset;
500 	__le32 count;
501 } __attribute__ ((__packed__));
502 
503 struct btrfs_shared_data_ref {
504 	__le32 count;
505 } __attribute__ ((__packed__));
506 
507 struct btrfs_extent_inline_ref {
508 	__u8 type;
509 	__le64 offset;
510 } __attribute__ ((__packed__));
511 
512 /* old style backrefs item */
513 struct btrfs_extent_ref_v0 {
514 	__le64 root;
515 	__le64 generation;
516 	__le64 objectid;
517 	__le32 count;
518 } __attribute__ ((__packed__));
519 
520 
521 /* dev extents record free space on individual devices.  The owner
522  * field points back to the chunk allocation mapping tree that allocated
523  * the extent.  The chunk tree uuid field is a way to double check the owner
524  */
525 struct btrfs_dev_extent {
526 	__le64 chunk_tree;
527 	__le64 chunk_objectid;
528 	__le64 chunk_offset;
529 	__le64 length;
530 	__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
531 } __attribute__ ((__packed__));
532 
533 struct btrfs_inode_ref {
534 	__le64 index;
535 	__le16 name_len;
536 	/* name goes here */
537 } __attribute__ ((__packed__));
538 
539 struct btrfs_inode_extref {
540 	__le64 parent_objectid;
541 	__le64 index;
542 	__le16 name_len;
543 	__u8   name[0];
544 	/* name goes here */
545 } __attribute__ ((__packed__));
546 
547 struct btrfs_timespec {
548 	__le64 sec;
549 	__le32 nsec;
550 } __attribute__ ((__packed__));
551 
552 struct btrfs_inode_item {
553 	/* nfs style generation number */
554 	__le64 generation;
555 	/* transid that last touched this inode */
556 	__le64 transid;
557 	__le64 size;
558 	__le64 nbytes;
559 	__le64 block_group;
560 	__le32 nlink;
561 	__le32 uid;
562 	__le32 gid;
563 	__le32 mode;
564 	__le64 rdev;
565 	__le64 flags;
566 
567 	/* modification sequence number for NFS */
568 	__le64 sequence;
569 
570 	/*
571 	 * a little future expansion, for more than this we can
572 	 * just grow the inode item and version it
573 	 */
574 	__le64 reserved[4];
575 	struct btrfs_timespec atime;
576 	struct btrfs_timespec ctime;
577 	struct btrfs_timespec mtime;
578 	struct btrfs_timespec otime;
579 } __attribute__ ((__packed__));
580 
581 struct btrfs_dir_log_item {
582 	__le64 end;
583 } __attribute__ ((__packed__));
584 
585 struct btrfs_dir_item {
586 	struct btrfs_disk_key location;
587 	__le64 transid;
588 	__le16 data_len;
589 	__le16 name_len;
590 	__u8 type;
591 } __attribute__ ((__packed__));
592 
593 #define BTRFS_ROOT_SUBVOL_RDONLY	(1ULL << 0)
594 
595 /*
596  * Internal in-memory flag that a subvolume has been marked for deletion but
597  * still visible as a directory
598  */
599 #define BTRFS_ROOT_SUBVOL_DEAD		(1ULL << 48)
600 
601 struct btrfs_root_item {
602 	struct btrfs_inode_item inode;
603 	__le64 generation;
604 	__le64 root_dirid;
605 	__le64 bytenr;
606 	__le64 byte_limit;
607 	__le64 bytes_used;
608 	__le64 last_snapshot;
609 	__le64 flags;
610 	__le32 refs;
611 	struct btrfs_disk_key drop_progress;
612 	__u8 drop_level;
613 	__u8 level;
614 
615 	/*
616 	 * The following fields appear after subvol_uuids+subvol_times
617 	 * were introduced.
618 	 */
619 
620 	/*
621 	 * This generation number is used to test if the new fields are valid
622 	 * and up to date while reading the root item. Every time the root item
623 	 * is written out, the "generation" field is copied into this field. If
624 	 * anyone ever mounted the fs with an older kernel, we will have
625 	 * mismatching generation values here and thus must invalidate the
626 	 * new fields. See btrfs_update_root and btrfs_find_last_root for
627 	 * details.
628 	 * the offset of generation_v2 is also used as the start for the memset
629 	 * when invalidating the fields.
630 	 */
631 	__le64 generation_v2;
632 	__u8 uuid[BTRFS_UUID_SIZE];
633 	__u8 parent_uuid[BTRFS_UUID_SIZE];
634 	__u8 received_uuid[BTRFS_UUID_SIZE];
635 	__le64 ctransid; /* updated when an inode changes */
636 	__le64 otransid; /* trans when created */
637 	__le64 stransid; /* trans when sent. non-zero for received subvol */
638 	__le64 rtransid; /* trans when received. non-zero for received subvol */
639 	struct btrfs_timespec ctime;
640 	struct btrfs_timespec otime;
641 	struct btrfs_timespec stime;
642 	struct btrfs_timespec rtime;
643 	__le64 reserved[8]; /* for future */
644 } __attribute__ ((__packed__));
645 
646 /*
647  * this is used for both forward and backward root refs
648  */
649 struct btrfs_root_ref {
650 	__le64 dirid;
651 	__le64 sequence;
652 	__le16 name_len;
653 } __attribute__ ((__packed__));
654 
655 struct btrfs_disk_balance_args {
656 	/*
657 	 * profiles to operate on, single is denoted by
658 	 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
659 	 */
660 	__le64 profiles;
661 
662 	/*
663 	 * usage filter
664 	 * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N'
665 	 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
666 	 */
667 	union {
668 		__le64 usage;
669 		struct {
670 			__le32 usage_min;
671 			__le32 usage_max;
672 		};
673 	};
674 
675 	/* devid filter */
676 	__le64 devid;
677 
678 	/* devid subset filter [pstart..pend) */
679 	__le64 pstart;
680 	__le64 pend;
681 
682 	/* btrfs virtual address space subset filter [vstart..vend) */
683 	__le64 vstart;
684 	__le64 vend;
685 
686 	/*
687 	 * profile to convert to, single is denoted by
688 	 * BTRFS_AVAIL_ALLOC_BIT_SINGLE
689 	 */
690 	__le64 target;
691 
692 	/* BTRFS_BALANCE_ARGS_* */
693 	__le64 flags;
694 
695 	/*
696 	 * BTRFS_BALANCE_ARGS_LIMIT with value 'limit'
697 	 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum
698 	 * and maximum
699 	 */
700 	union {
701 		__le64 limit;
702 		struct {
703 			__le32 limit_min;
704 			__le32 limit_max;
705 		};
706 	};
707 
708 	/*
709 	 * Process chunks that cross stripes_min..stripes_max devices,
710 	 * BTRFS_BALANCE_ARGS_STRIPES_RANGE
711 	 */
712 	__le32 stripes_min;
713 	__le32 stripes_max;
714 
715 	__le64 unused[6];
716 } __attribute__ ((__packed__));
717 
718 /*
719  * store balance parameters to disk so that balance can be properly
720  * resumed after crash or unmount
721  */
722 struct btrfs_balance_item {
723 	/* BTRFS_BALANCE_* */
724 	__le64 flags;
725 
726 	struct btrfs_disk_balance_args data;
727 	struct btrfs_disk_balance_args meta;
728 	struct btrfs_disk_balance_args sys;
729 
730 	__le64 unused[4];
731 } __attribute__ ((__packed__));
732 
733 #define BTRFS_FILE_EXTENT_INLINE 0
734 #define BTRFS_FILE_EXTENT_REG 1
735 #define BTRFS_FILE_EXTENT_PREALLOC 2
736 #define BTRFS_FILE_EXTENT_TYPES	2
737 
738 struct btrfs_file_extent_item {
739 	/*
740 	 * transaction id that created this extent
741 	 */
742 	__le64 generation;
743 	/*
744 	 * max number of bytes to hold this extent in ram
745 	 * when we split a compressed extent we can't know how big
746 	 * each of the resulting pieces will be.  So, this is
747 	 * an upper limit on the size of the extent in ram instead of
748 	 * an exact limit.
749 	 */
750 	__le64 ram_bytes;
751 
752 	/*
753 	 * 32 bits for the various ways we might encode the data,
754 	 * including compression and encryption.  If any of these
755 	 * are set to something a given disk format doesn't understand
756 	 * it is treated like an incompat flag for reading and writing,
757 	 * but not for stat.
758 	 */
759 	__u8 compression;
760 	__u8 encryption;
761 	__le16 other_encoding; /* spare for later use */
762 
763 	/* are we inline data or a real extent? */
764 	__u8 type;
765 
766 	/*
767 	 * disk space consumed by the extent, checksum blocks are included
768 	 * in these numbers
769 	 *
770 	 * At this offset in the structure, the inline extent data start.
771 	 */
772 	__le64 disk_bytenr;
773 	__le64 disk_num_bytes;
774 	/*
775 	 * the logical offset in file blocks (no csums)
776 	 * this extent record is for.  This allows a file extent to point
777 	 * into the middle of an existing extent on disk, sharing it
778 	 * between two snapshots (useful if some bytes in the middle of the
779 	 * extent have changed
780 	 */
781 	__le64 offset;
782 	/*
783 	 * the logical number of file blocks (no csums included).  This
784 	 * always reflects the size uncompressed and without encoding.
785 	 */
786 	__le64 num_bytes;
787 
788 } __attribute__ ((__packed__));
789 
790 struct btrfs_csum_item {
791 	__u8 csum;
792 } __attribute__ ((__packed__));
793 
794 struct btrfs_dev_stats_item {
795 	/*
796 	 * grow this item struct at the end for future enhancements and keep
797 	 * the existing values unchanged
798 	 */
799 	__le64 values[BTRFS_DEV_STAT_VALUES_MAX];
800 } __attribute__ ((__packed__));
801 
802 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_ALWAYS	0
803 #define BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID	1
804 #define BTRFS_DEV_REPLACE_ITEM_STATE_NEVER_STARTED	0
805 #define BTRFS_DEV_REPLACE_ITEM_STATE_STARTED		1
806 #define BTRFS_DEV_REPLACE_ITEM_STATE_SUSPENDED		2
807 #define BTRFS_DEV_REPLACE_ITEM_STATE_FINISHED		3
808 #define BTRFS_DEV_REPLACE_ITEM_STATE_CANCELED		4
809 
810 struct btrfs_dev_replace_item {
811 	/*
812 	 * grow this item struct at the end for future enhancements and keep
813 	 * the existing values unchanged
814 	 */
815 	__le64 src_devid;
816 	__le64 cursor_left;
817 	__le64 cursor_right;
818 	__le64 cont_reading_from_srcdev_mode;
819 
820 	__le64 replace_state;
821 	__le64 time_started;
822 	__le64 time_stopped;
823 	__le64 num_write_errors;
824 	__le64 num_uncorrectable_read_errors;
825 } __attribute__ ((__packed__));
826 
827 /* different types of block groups (and chunks) */
828 #define BTRFS_BLOCK_GROUP_DATA		(1ULL << 0)
829 #define BTRFS_BLOCK_GROUP_SYSTEM	(1ULL << 1)
830 #define BTRFS_BLOCK_GROUP_METADATA	(1ULL << 2)
831 #define BTRFS_BLOCK_GROUP_RAID0		(1ULL << 3)
832 #define BTRFS_BLOCK_GROUP_RAID1		(1ULL << 4)
833 #define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)
834 #define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)
835 #define BTRFS_BLOCK_GROUP_RAID5         (1ULL << 7)
836 #define BTRFS_BLOCK_GROUP_RAID6         (1ULL << 8)
837 #define BTRFS_BLOCK_GROUP_RESERVED	(BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
838 					 BTRFS_SPACE_INFO_GLOBAL_RSV)
839 
840 enum btrfs_raid_types {
841 	BTRFS_RAID_RAID10,
842 	BTRFS_RAID_RAID1,
843 	BTRFS_RAID_DUP,
844 	BTRFS_RAID_RAID0,
845 	BTRFS_RAID_SINGLE,
846 	BTRFS_RAID_RAID5,
847 	BTRFS_RAID_RAID6,
848 	BTRFS_NR_RAID_TYPES
849 };
850 
851 #define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
852 					 BTRFS_BLOCK_GROUP_SYSTEM |  \
853 					 BTRFS_BLOCK_GROUP_METADATA)
854 
855 #define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
856 					 BTRFS_BLOCK_GROUP_RAID1 |   \
857 					 BTRFS_BLOCK_GROUP_RAID5 |   \
858 					 BTRFS_BLOCK_GROUP_RAID6 |   \
859 					 BTRFS_BLOCK_GROUP_DUP |     \
860 					 BTRFS_BLOCK_GROUP_RAID10)
861 #define BTRFS_BLOCK_GROUP_RAID56_MASK	(BTRFS_BLOCK_GROUP_RAID5 |   \
862 					 BTRFS_BLOCK_GROUP_RAID6)
863 
864 /*
865  * We need a bit for restriper to be able to tell when chunks of type
866  * SINGLE are available.  This "extended" profile format is used in
867  * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
868  * (on-disk).  The corresponding on-disk bit in chunk.type is reserved
869  * to avoid remappings between two formats in future.
870  */
871 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
872 
873 /*
874  * A fake block group type that is used to communicate global block reserve
875  * size to userspace via the SPACE_INFO ioctl.
876  */
877 #define BTRFS_SPACE_INFO_GLOBAL_RSV	(1ULL << 49)
878 
879 #define BTRFS_EXTENDED_PROFILE_MASK	(BTRFS_BLOCK_GROUP_PROFILE_MASK | \
880 					 BTRFS_AVAIL_ALLOC_BIT_SINGLE)
881 
882 static inline __u64 chunk_to_extended(__u64 flags)
883 {
884 	if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0)
885 		flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE;
886 
887 	return flags;
888 }
889 static inline __u64 extended_to_chunk(__u64 flags)
890 {
891 	return flags & ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
892 }
893 
894 struct btrfs_block_group_item {
895 	__le64 used;
896 	__le64 chunk_objectid;
897 	__le64 flags;
898 } __attribute__ ((__packed__));
899 
900 struct btrfs_free_space_info {
901 	__le32 extent_count;
902 	__le32 flags;
903 } __attribute__ ((__packed__));
904 
905 #define BTRFS_FREE_SPACE_USING_BITMAPS (1ULL << 0)
906 
907 #define BTRFS_QGROUP_LEVEL_SHIFT		48
908 static inline __u64 btrfs_qgroup_level(__u64 qgroupid)
909 {
910 	return qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT;
911 }
912 
913 /*
914  * is subvolume quota turned on?
915  */
916 #define BTRFS_QGROUP_STATUS_FLAG_ON		(1ULL << 0)
917 /*
918  * RESCAN is set during the initialization phase
919  */
920 #define BTRFS_QGROUP_STATUS_FLAG_RESCAN		(1ULL << 1)
921 /*
922  * Some qgroup entries are known to be out of date,
923  * either because the configuration has changed in a way that
924  * makes a rescan necessary, or because the fs has been mounted
925  * with a non-qgroup-aware version.
926  * Turning qouta off and on again makes it inconsistent, too.
927  */
928 #define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT	(1ULL << 2)
929 
930 #define BTRFS_QGROUP_STATUS_VERSION        1
931 
932 struct btrfs_qgroup_status_item {
933 	__le64 version;
934 	/*
935 	 * the generation is updated during every commit. As older
936 	 * versions of btrfs are not aware of qgroups, it will be
937 	 * possible to detect inconsistencies by checking the
938 	 * generation on mount time
939 	 */
940 	__le64 generation;
941 
942 	/* flag definitions see above */
943 	__le64 flags;
944 
945 	/*
946 	 * only used during scanning to record the progress
947 	 * of the scan. It contains a logical address
948 	 */
949 	__le64 rescan;
950 } __attribute__ ((__packed__));
951 
952 struct btrfs_qgroup_info_item {
953 	__le64 generation;
954 	__le64 rfer;
955 	__le64 rfer_cmpr;
956 	__le64 excl;
957 	__le64 excl_cmpr;
958 } __attribute__ ((__packed__));
959 
960 struct btrfs_qgroup_limit_item {
961 	/*
962 	 * only updated when any of the other values change
963 	 */
964 	__le64 flags;
965 	__le64 max_rfer;
966 	__le64 max_excl;
967 	__le64 rsv_rfer;
968 	__le64 rsv_excl;
969 } __attribute__ ((__packed__));
970 
971 #endif /* _BTRFS_CTREE_H_ */
972