xref: /openbmc/u-boot/fs/btrfs/btrfs_tree.h (revision baefb63a)
1 /*
2  * From linux/include/uapi/linux/btrfs_tree.h
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #ifndef __BTRFS_BTRFS_TREE_H__
8 #define __BTRFS_BTRFS_TREE_H__
9 
10 #include <common.h>
11 
12 #define BTRFS_VOL_NAME_MAX 255
13 #define BTRFS_NAME_MAX 255
14 #define BTRFS_LABEL_SIZE 256
15 #define BTRFS_FSID_SIZE 16
16 #define BTRFS_UUID_SIZE 16
17 
18 /*
19  * This header contains the structure definitions and constants used
20  * by file system objects that can be retrieved using
21  * the BTRFS_IOC_SEARCH_TREE ioctl.  That means basically anything that
22  * is needed to describe a leaf node's key or item contents.
23  */
24 
25 /* holds pointers to all of the tree roots */
26 #define BTRFS_ROOT_TREE_OBJECTID 1ULL
27 
28 /* stores information about which extents are in use, and reference counts */
29 #define BTRFS_EXTENT_TREE_OBJECTID 2ULL
30 
31 /*
32  * chunk tree stores translations from logical -> physical block numbering
33  * the super block points to the chunk tree
34  */
35 #define BTRFS_CHUNK_TREE_OBJECTID 3ULL
36 
37 /*
38  * stores information about which areas of a given device are in use.
39  * one per device.  The tree of tree roots points to the device tree
40  */
41 #define BTRFS_DEV_TREE_OBJECTID 4ULL
42 
43 /* one per subvolume, storing files and directories */
44 #define BTRFS_FS_TREE_OBJECTID 5ULL
45 
46 /* directory objectid inside the root tree */
47 #define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
48 
49 /* holds checksums of all the data extents */
50 #define BTRFS_CSUM_TREE_OBJECTID 7ULL
51 
52 /* holds quota configuration and tracking */
53 #define BTRFS_QUOTA_TREE_OBJECTID 8ULL
54 
55 /* for storing items that use the BTRFS_UUID_KEY* types */
56 #define BTRFS_UUID_TREE_OBJECTID 9ULL
57 
58 /* tracks free space in block groups. */
59 #define BTRFS_FREE_SPACE_TREE_OBJECTID 10ULL
60 
61 /* device stats in the device tree */
62 #define BTRFS_DEV_STATS_OBJECTID 0ULL
63 
64 /* for storing balance parameters in the root tree */
65 #define BTRFS_BALANCE_OBJECTID -4ULL
66 
67 /* orhpan objectid for tracking unlinked/truncated files */
68 #define BTRFS_ORPHAN_OBJECTID -5ULL
69 
70 /* does write ahead logging to speed up fsyncs */
71 #define BTRFS_TREE_LOG_OBJECTID -6ULL
72 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
73 
74 /* for space balancing */
75 #define BTRFS_TREE_RELOC_OBJECTID -8ULL
76 #define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
77 
78 /*
79  * extent checksums all have this objectid
80  * this allows them to share the logging tree
81  * for fsyncs
82  */
83 #define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
84 
85 /* For storing free space cache */
86 #define BTRFS_FREE_SPACE_OBJECTID -11ULL
87 
88 /*
89  * The inode number assigned to the special inode for storing
90  * free ino cache
91  */
92 #define BTRFS_FREE_INO_OBJECTID -12ULL
93 
94 /* dummy objectid represents multiple objectids */
95 #define BTRFS_MULTIPLE_OBJECTIDS -255ULL
96 
97 /*
98  * All files have objectids in this range.
99  */
100 #define BTRFS_FIRST_FREE_OBJECTID 256ULL
101 #define BTRFS_LAST_FREE_OBJECTID -256ULL
102 #define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL
103 
104 
105 /*
106  * the device items go into the chunk tree.  The key is in the form
107  * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
108  */
109 #define BTRFS_DEV_ITEMS_OBJECTID 1ULL
110 
111 #define BTRFS_BTREE_INODE_OBJECTID 1
112 
113 #define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2
114 
115 #define BTRFS_DEV_REPLACE_DEVID 0ULL
116 
117 /*
118  * inode items have the data typically returned from stat and store other
119  * info about object characteristics.  There is one for every file and dir in
120  * the FS
121  */
122 #define BTRFS_INODE_ITEM_KEY		1
123 #define BTRFS_INODE_REF_KEY		12
124 #define BTRFS_INODE_EXTREF_KEY		13
125 #define BTRFS_XATTR_ITEM_KEY		24
126 #define BTRFS_ORPHAN_ITEM_KEY		48
127 /* reserve 2-15 close to the inode for later flexibility */
128 
129 /*
130  * dir items are the name -> inode pointers in a directory.  There is one
131  * for every name in a directory.
132  */
133 #define BTRFS_DIR_LOG_ITEM_KEY  60
134 #define BTRFS_DIR_LOG_INDEX_KEY 72
135 #define BTRFS_DIR_ITEM_KEY	84
136 #define BTRFS_DIR_INDEX_KEY	96
137 /*
138  * extent data is for file data
139  */
140 #define BTRFS_EXTENT_DATA_KEY	108
141 
142 /*
143  * extent csums are stored in a separate tree and hold csums for
144  * an entire extent on disk.
145  */
146 #define BTRFS_EXTENT_CSUM_KEY	128
147 
148 /*
149  * root items point to tree roots.  They are typically in the root
150  * tree used by the super block to find all the other trees
151  */
152 #define BTRFS_ROOT_ITEM_KEY	132
153 
154 /*
155  * root backrefs tie subvols and snapshots to the directory entries that
156  * reference them
157  */
158 #define BTRFS_ROOT_BACKREF_KEY	144
159 
160 /*
161  * root refs make a fast index for listing all of the snapshots and
162  * subvolumes referenced by a given root.  They point directly to the
163  * directory item in the root that references the subvol
164  */
165 #define BTRFS_ROOT_REF_KEY	156
166 
167 /*
168  * extent items are in the extent map tree.  These record which blocks
169  * are used, and how many references there are to each block
170  */
171 #define BTRFS_EXTENT_ITEM_KEY	168
172 
173 /*
174  * The same as the BTRFS_EXTENT_ITEM_KEY, except it's metadata we already know
175  * the length, so we save the level in key->offset instead of the length.
176  */
177 #define BTRFS_METADATA_ITEM_KEY	169
178 
179 #define BTRFS_TREE_BLOCK_REF_KEY	176
180 
181 #define BTRFS_EXTENT_DATA_REF_KEY	178
182 
183 #define BTRFS_EXTENT_REF_V0_KEY		180
184 
185 #define BTRFS_SHARED_BLOCK_REF_KEY	182
186 
187 #define BTRFS_SHARED_DATA_REF_KEY	184
188 
189 /*
190  * block groups give us hints into the extent allocation trees.  Which
191  * blocks are free etc etc
192  */
193 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192
194 
195 /*
196  * Every block group is represented in the free space tree by a free space info
197  * item, which stores some accounting information. It is keyed on
198  * (block_group_start, FREE_SPACE_INFO, block_group_length).
199  */
200 #define BTRFS_FREE_SPACE_INFO_KEY 198
201 
202 /*
203  * A free space extent tracks an extent of space that is free in a block group.
204  * It is keyed on (start, FREE_SPACE_EXTENT, length).
205  */
206 #define BTRFS_FREE_SPACE_EXTENT_KEY 199
207 
208 /*
209  * When a block group becomes very fragmented, we convert it to use bitmaps
210  * instead of extents. A free space bitmap is keyed on
211  * (start, FREE_SPACE_BITMAP, length); the corresponding item is a bitmap with
212  * (length / sectorsize) bits.
213  */
214 #define BTRFS_FREE_SPACE_BITMAP_KEY 200
215 
216 #define BTRFS_DEV_EXTENT_KEY	204
217 #define BTRFS_DEV_ITEM_KEY	216
218 #define BTRFS_CHUNK_ITEM_KEY	228
219 
220 /*
221  * Records the overall state of the qgroups.
222  * There's only one instance of this key present,
223  * (0, BTRFS_QGROUP_STATUS_KEY, 0)
224  */
225 #define BTRFS_QGROUP_STATUS_KEY         240
226 /*
227  * Records the currently used space of the qgroup.
228  * One key per qgroup, (0, BTRFS_QGROUP_INFO_KEY, qgroupid).
229  */
230 #define BTRFS_QGROUP_INFO_KEY           242
231 /*
232  * Contains the user configured limits for the qgroup.
233  * One key per qgroup, (0, BTRFS_QGROUP_LIMIT_KEY, qgroupid).
234  */
235 #define BTRFS_QGROUP_LIMIT_KEY          244
236 /*
237  * Records the child-parent relationship of qgroups. For
238  * each relation, 2 keys are present:
239  * (childid, BTRFS_QGROUP_RELATION_KEY, parentid)
240  * (parentid, BTRFS_QGROUP_RELATION_KEY, childid)
241  */
242 #define BTRFS_QGROUP_RELATION_KEY       246
243 
244 /*
245  * Obsolete name, see BTRFS_TEMPORARY_ITEM_KEY.
246  */
247 #define BTRFS_BALANCE_ITEM_KEY	248
248 
249 /*
250  * The key type for tree items that are stored persistently, but do not need to
251  * exist for extended period of time. The items can exist in any tree.
252  *
253  * [subtype, BTRFS_TEMPORARY_ITEM_KEY, data]
254  *
255  * Existing items:
256  *
257  * - balance status item
258  *   (BTRFS_BALANCE_OBJECTID, BTRFS_TEMPORARY_ITEM_KEY, 0)
259  */
260 #define BTRFS_TEMPORARY_ITEM_KEY	248
261 
262 /*
263  * Obsolete name, see BTRFS_PERSISTENT_ITEM_KEY
264  */
265 #define BTRFS_DEV_STATS_KEY		249
266 
267 /*
268  * The key type for tree items that are stored persistently and usually exist
269  * for a long period, eg. filesystem lifetime. The item kinds can be status
270  * information, stats or preference values. The item can exist in any tree.
271  *
272  * [subtype, BTRFS_PERSISTENT_ITEM_KEY, data]
273  *
274  * Existing items:
275  *
276  * - device statistics, store IO stats in the device tree, one key for all
277  *   stats
278  *   (BTRFS_DEV_STATS_OBJECTID, BTRFS_DEV_STATS_KEY, 0)
279  */
280 #define BTRFS_PERSISTENT_ITEM_KEY	249
281 
282 /*
283  * Persistantly stores the device replace state in the device tree.
284  * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
285  */
286 #define BTRFS_DEV_REPLACE_KEY	250
287 
288 /*
289  * Stores items that allow to quickly map UUIDs to something else.
290  * These items are part of the filesystem UUID tree.
291  * The key is built like this:
292  * (UUID_upper_64_bits, BTRFS_UUID_KEY*, UUID_lower_64_bits).
293  */
294 #if BTRFS_UUID_SIZE != 16
295 #error "UUID items require BTRFS_UUID_SIZE == 16!"
296 #endif
297 #define BTRFS_UUID_KEY_SUBVOL	251	/* for UUIDs assigned to subvols */
298 #define BTRFS_UUID_KEY_RECEIVED_SUBVOL	252	/* for UUIDs assigned to
299 						 * received subvols */
300 
301 /*
302  * string items are for debugging.  They just store a short string of
303  * data in the FS
304  */
305 #define BTRFS_STRING_ITEM_KEY	253
306 
307 
308 
309 /* 32 bytes in various csum fields */
310 #define BTRFS_CSUM_SIZE 32
311 
312 /* csum types */
313 #define BTRFS_CSUM_TYPE_CRC32	0
314 
315 /*
316  * flags definitions for directory entry item type
317  *
318  * Used by:
319  * struct btrfs_dir_item.type
320  */
321 #define BTRFS_FT_UNKNOWN	0
322 #define BTRFS_FT_REG_FILE	1
323 #define BTRFS_FT_DIR		2
324 #define BTRFS_FT_CHRDEV		3
325 #define BTRFS_FT_BLKDEV		4
326 #define BTRFS_FT_FIFO		5
327 #define BTRFS_FT_SOCK		6
328 #define BTRFS_FT_SYMLINK	7
329 #define BTRFS_FT_XATTR		8
330 #define BTRFS_FT_MAX		9
331 
332 /*
333  * The key defines the order in the tree, and so it also defines (optimal)
334  * block layout.
335  *
336  * objectid corresponds to the inode number.
337  *
338  * type tells us things about the object, and is a kind of stream selector.
339  * so for a given inode, keys with type of 1 might refer to the inode data,
340  * type of 2 may point to file data in the btree and type == 3 may point to
341  * extents.
342  *
343  * offset is the starting byte offset for this key in the stream.
344  */
345 
346 struct btrfs_key {
347 	__u64 objectid;
348 	__u8 type;
349 	__u64 offset;
350 } __attribute__ ((__packed__));
351 
352 struct btrfs_dev_item {
353 	/* the internal btrfs device id */
354 	__u64 devid;
355 
356 	/* size of the device */
357 	__u64 total_bytes;
358 
359 	/* bytes used */
360 	__u64 bytes_used;
361 
362 	/* optimal io alignment for this device */
363 	__u32 io_align;
364 
365 	/* optimal io width for this device */
366 	__u32 io_width;
367 
368 	/* minimal io size for this device */
369 	__u32 sector_size;
370 
371 	/* type and info about this device */
372 	__u64 type;
373 
374 	/* expected generation for this device */
375 	__u64 generation;
376 
377 	/*
378 	 * starting byte of this partition on the device,
379 	 * to allow for stripe alignment in the future
380 	 */
381 	__u64 start_offset;
382 
383 	/* grouping information for allocation decisions */
384 	__u32 dev_group;
385 
386 	/* seek speed 0-100 where 100 is fastest */
387 	__u8 seek_speed;
388 
389 	/* bandwidth 0-100 where 100 is fastest */
390 	__u8 bandwidth;
391 
392 	/* btrfs generated uuid for this device */
393 	__u8 uuid[BTRFS_UUID_SIZE];
394 
395 	/* uuid of FS who owns this device */
396 	__u8 fsid[BTRFS_UUID_SIZE];
397 } __attribute__ ((__packed__));
398 
399 struct btrfs_stripe {
400 	__u64 devid;
401 	__u64 offset;
402 	__u8 dev_uuid[BTRFS_UUID_SIZE];
403 } __attribute__ ((__packed__));
404 
405 struct btrfs_chunk {
406 	/* size of this chunk in bytes */
407 	__u64 length;
408 
409 	/* objectid of the root referencing this chunk */
410 	__u64 owner;
411 
412 	__u64 stripe_len;
413 	__u64 type;
414 
415 	/* optimal io alignment for this chunk */
416 	__u32 io_align;
417 
418 	/* optimal io width for this chunk */
419 	__u32 io_width;
420 
421 	/* minimal io size for this chunk */
422 	__u32 sector_size;
423 
424 	/* 2^16 stripes is quite a lot, a second limit is the size of a single
425 	 * item in the btree
426 	 */
427 	__u16 num_stripes;
428 
429 	/* sub stripes only matter for raid10 */
430 	__u16 sub_stripes;
431 	struct btrfs_stripe stripe;
432 	/* additional stripes go here */
433 } __attribute__ ((__packed__));
434 
435 #define BTRFS_FREE_SPACE_EXTENT	1
436 #define BTRFS_FREE_SPACE_BITMAP	2
437 
438 struct btrfs_free_space_entry {
439 	__u64 offset;
440 	__u64 bytes;
441 	__u8 type;
442 } __attribute__ ((__packed__));
443 
444 struct btrfs_free_space_header {
445 	struct btrfs_key location;
446 	__u64 generation;
447 	__u64 num_entries;
448 	__u64 num_bitmaps;
449 } __attribute__ ((__packed__));
450 
451 #define BTRFS_HEADER_FLAG_WRITTEN	(1ULL << 0)
452 #define BTRFS_HEADER_FLAG_RELOC		(1ULL << 1)
453 
454 /* Super block flags */
455 /* Errors detected */
456 #define BTRFS_SUPER_FLAG_ERROR		(1ULL << 2)
457 
458 #define BTRFS_SUPER_FLAG_SEEDING	(1ULL << 32)
459 #define BTRFS_SUPER_FLAG_METADUMP	(1ULL << 33)
460 
461 
462 /*
463  * items in the extent btree are used to record the objectid of the
464  * owner of the block and the number of references
465  */
466 
467 struct btrfs_extent_item {
468 	__u64 refs;
469 	__u64 generation;
470 	__u64 flags;
471 } __attribute__ ((__packed__));
472 
473 
474 #define BTRFS_EXTENT_FLAG_DATA		(1ULL << 0)
475 #define BTRFS_EXTENT_FLAG_TREE_BLOCK	(1ULL << 1)
476 
477 /* following flags only apply to tree blocks */
478 
479 /* use full backrefs for extent pointers in the block */
480 #define BTRFS_BLOCK_FLAG_FULL_BACKREF	(1ULL << 8)
481 
482 /*
483  * this flag is only used internally by scrub and may be changed at any time
484  * it is only declared here to avoid collisions
485  */
486 #define BTRFS_EXTENT_FLAG_SUPER		(1ULL << 48)
487 
488 struct btrfs_tree_block_info {
489 	struct btrfs_key key;
490 	__u8 level;
491 } __attribute__ ((__packed__));
492 
493 struct btrfs_extent_data_ref {
494 	__u64 root;
495 	__u64 objectid;
496 	__u64 offset;
497 	__u32 count;
498 } __attribute__ ((__packed__));
499 
500 struct btrfs_shared_data_ref {
501 	__u32 count;
502 } __attribute__ ((__packed__));
503 
504 struct btrfs_extent_inline_ref {
505 	__u8 type;
506 	__u64 offset;
507 } __attribute__ ((__packed__));
508 
509 /* dev extents record free space on individual devices.  The owner
510  * field points back to the chunk allocation mapping tree that allocated
511  * the extent.  The chunk tree uuid field is a way to double check the owner
512  */
513 struct btrfs_dev_extent {
514 	__u64 chunk_tree;
515 	__u64 chunk_objectid;
516 	__u64 chunk_offset;
517 	__u64 length;
518 	__u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
519 } __attribute__ ((__packed__));
520 
521 struct btrfs_inode_ref {
522 	__u64 index;
523 	__u16 name_len;
524 	/* name goes here */
525 } __attribute__ ((__packed__));
526 
527 struct btrfs_inode_extref {
528 	__u64 parent_objectid;
529 	__u64 index;
530 	__u16 name_len;
531 	__u8   name[0];
532 	/* name goes here */
533 } __attribute__ ((__packed__));
534 
535 struct btrfs_timespec {
536 	__u64 sec;
537 	__u32 nsec;
538 } __attribute__ ((__packed__));
539 
540 struct btrfs_inode_item {
541 	/* nfs style generation number */
542 	__u64 generation;
543 	/* transid that last touched this inode */
544 	__u64 transid;
545 	__u64 size;
546 	__u64 nbytes;
547 	__u64 block_group;
548 	__u32 nlink;
549 	__u32 uid;
550 	__u32 gid;
551 	__u32 mode;
552 	__u64 rdev;
553 	__u64 flags;
554 
555 	/* modification sequence number for NFS */
556 	__u64 sequence;
557 
558 	/*
559 	 * a little future expansion, for more than this we can
560 	 * just grow the inode item and version it
561 	 */
562 	__u64 reserved[4];
563 	struct btrfs_timespec atime;
564 	struct btrfs_timespec ctime;
565 	struct btrfs_timespec mtime;
566 	struct btrfs_timespec otime;
567 } __attribute__ ((__packed__));
568 
569 struct btrfs_dir_log_item {
570 	__u64 end;
571 } __attribute__ ((__packed__));
572 
573 struct btrfs_dir_item {
574 	struct btrfs_key location;
575 	__u64 transid;
576 	__u16 data_len;
577 	__u16 name_len;
578 	__u8 type;
579 } __attribute__ ((__packed__));
580 
581 #define BTRFS_ROOT_SUBVOL_RDONLY	(1ULL << 0)
582 
583 /*
584  * Internal in-memory flag that a subvolume has been marked for deletion but
585  * still visible as a directory
586  */
587 #define BTRFS_ROOT_SUBVOL_DEAD		(1ULL << 48)
588 
589 struct btrfs_root_item {
590 	struct btrfs_inode_item inode;
591 	__u64 generation;
592 	__u64 root_dirid;
593 	__u64 bytenr;
594 	__u64 byte_limit;
595 	__u64 bytes_used;
596 	__u64 last_snapshot;
597 	__u64 flags;
598 	__u32 refs;
599 	struct btrfs_key drop_progress;
600 	__u8 drop_level;
601 	__u8 level;
602 
603 	/*
604 	 * The following fields appear after subvol_uuids+subvol_times
605 	 * were introduced.
606 	 */
607 
608 	/*
609 	 * This generation number is used to test if the new fields are valid
610 	 * and up to date while reading the root item. Every time the root item
611 	 * is written out, the "generation" field is copied into this field. If
612 	 * anyone ever mounted the fs with an older kernel, we will have
613 	 * mismatching generation values here and thus must invalidate the
614 	 * new fields. See btrfs_update_root and btrfs_find_last_root for
615 	 * details.
616 	 * the offset of generation_v2 is also used as the start for the memset
617 	 * when invalidating the fields.
618 	 */
619 	__u64 generation_v2;
620 	__u8 uuid[BTRFS_UUID_SIZE];
621 	__u8 parent_uuid[BTRFS_UUID_SIZE];
622 	__u8 received_uuid[BTRFS_UUID_SIZE];
623 	__u64 ctransid; /* updated when an inode changes */
624 	__u64 otransid; /* trans when created */
625 	__u64 stransid; /* trans when sent. non-zero for received subvol */
626 	__u64 rtransid; /* trans when received. non-zero for received subvol */
627 	struct btrfs_timespec ctime;
628 	struct btrfs_timespec otime;
629 	struct btrfs_timespec stime;
630 	struct btrfs_timespec rtime;
631 	__u64 reserved[8]; /* for future */
632 } __attribute__ ((__packed__));
633 
634 /*
635  * this is used for both forward and backward root refs
636  */
637 struct btrfs_root_ref {
638 	__u64 dirid;
639 	__u64 sequence;
640 	__u16 name_len;
641 } __attribute__ ((__packed__));
642 
643 #define BTRFS_FILE_EXTENT_INLINE 0
644 #define BTRFS_FILE_EXTENT_REG 1
645 #define BTRFS_FILE_EXTENT_PREALLOC 2
646 
647 enum btrfs_compression_type {
648 	BTRFS_COMPRESS_NONE  = 0,
649 	BTRFS_COMPRESS_ZLIB  = 1,
650 	BTRFS_COMPRESS_LZO   = 2,
651 	BTRFS_COMPRESS_TYPES = 2,
652 	BTRFS_COMPRESS_LAST  = 3,
653 };
654 
655 struct btrfs_file_extent_item {
656 	/*
657 	 * transaction id that created this extent
658 	 */
659 	__u64 generation;
660 	/*
661 	 * max number of bytes to hold this extent in ram
662 	 * when we split a compressed extent we can't know how big
663 	 * each of the resulting pieces will be.  So, this is
664 	 * an upper limit on the size of the extent in ram instead of
665 	 * an exact limit.
666 	 */
667 	__u64 ram_bytes;
668 
669 	/*
670 	 * 32 bits for the various ways we might encode the data,
671 	 * including compression and encryption.  If any of these
672 	 * are set to something a given disk format doesn't understand
673 	 * it is treated like an incompat flag for reading and writing,
674 	 * but not for stat.
675 	 */
676 	__u8 compression;
677 	__u8 encryption;
678 	__u16 other_encoding; /* spare for later use */
679 
680 	/* are we inline data or a real extent? */
681 	__u8 type;
682 
683 	/*
684 	 * disk space consumed by the extent, checksum blocks are included
685 	 * in these numbers
686 	 *
687 	 * At this offset in the structure, the inline extent data start.
688 	 */
689 	__u64 disk_bytenr;
690 	__u64 disk_num_bytes;
691 	/*
692 	 * the logical offset in file blocks (no csums)
693 	 * this extent record is for.  This allows a file extent to point
694 	 * into the middle of an existing extent on disk, sharing it
695 	 * between two snapshots (useful if some bytes in the middle of the
696 	 * extent have changed
697 	 */
698 	__u64 offset;
699 	/*
700 	 * the logical number of file blocks (no csums included).  This
701 	 * always reflects the size uncompressed and without encoding.
702 	 */
703 	__u64 num_bytes;
704 
705 } __attribute__ ((__packed__));
706 
707 struct btrfs_csum_item {
708 	__u8 csum;
709 } __attribute__ ((__packed__));
710 
711 /* different types of block groups (and chunks) */
712 #define BTRFS_BLOCK_GROUP_DATA		(1ULL << 0)
713 #define BTRFS_BLOCK_GROUP_SYSTEM	(1ULL << 1)
714 #define BTRFS_BLOCK_GROUP_METADATA	(1ULL << 2)
715 #define BTRFS_BLOCK_GROUP_RAID0		(1ULL << 3)
716 #define BTRFS_BLOCK_GROUP_RAID1		(1ULL << 4)
717 #define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)
718 #define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)
719 #define BTRFS_BLOCK_GROUP_RAID5         (1ULL << 7)
720 #define BTRFS_BLOCK_GROUP_RAID6         (1ULL << 8)
721 #define BTRFS_BLOCK_GROUP_RESERVED	(BTRFS_AVAIL_ALLOC_BIT_SINGLE | \
722 					 BTRFS_SPACE_INFO_GLOBAL_RSV)
723 
724 enum btrfs_raid_types {
725 	BTRFS_RAID_RAID10,
726 	BTRFS_RAID_RAID1,
727 	BTRFS_RAID_DUP,
728 	BTRFS_RAID_RAID0,
729 	BTRFS_RAID_SINGLE,
730 	BTRFS_RAID_RAID5,
731 	BTRFS_RAID_RAID6,
732 	BTRFS_NR_RAID_TYPES
733 };
734 
735 #define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
736 					 BTRFS_BLOCK_GROUP_SYSTEM |  \
737 					 BTRFS_BLOCK_GROUP_METADATA)
738 
739 #define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
740 					 BTRFS_BLOCK_GROUP_RAID1 |   \
741 					 BTRFS_BLOCK_GROUP_RAID5 |   \
742 					 BTRFS_BLOCK_GROUP_RAID6 |   \
743 					 BTRFS_BLOCK_GROUP_DUP |     \
744 					 BTRFS_BLOCK_GROUP_RAID10)
745 #define BTRFS_BLOCK_GROUP_RAID56_MASK	(BTRFS_BLOCK_GROUP_RAID5 |   \
746 					 BTRFS_BLOCK_GROUP_RAID6)
747 
748 /*
749  * We need a bit for restriper to be able to tell when chunks of type
750  * SINGLE are available.  This "extended" profile format is used in
751  * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
752  * (on-disk).  The corresponding on-disk bit in chunk.type is reserved
753  * to avoid remappings between two formats in future.
754  */
755 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
756 
757 /*
758  * A fake block group type that is used to communicate global block reserve
759  * size to userspace via the SPACE_INFO ioctl.
760  */
761 #define BTRFS_SPACE_INFO_GLOBAL_RSV	(1ULL << 49)
762 
763 #define BTRFS_EXTENDED_PROFILE_MASK	(BTRFS_BLOCK_GROUP_PROFILE_MASK | \
764 					 BTRFS_AVAIL_ALLOC_BIT_SINGLE)
765 
766 #endif /* __BTRFS_BTRFS_TREE_H__ */
767