xref: /linux/fs/bcachefs/bcachefs_format.h (revision 0759356bf5fadbd16794bec982a9af48351a02ff)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _BCACHEFS_FORMAT_H
3 #define _BCACHEFS_FORMAT_H
4 
5 /*
6  * bcachefs on disk data structures
7  *
8  * OVERVIEW:
9  *
10  * There are three main types of on disk data structures in bcachefs (this is
11  * reduced from 5 in bcache)
12  *
13  *  - superblock
14  *  - journal
15  *  - btree
16  *
17  * The btree is the primary structure; most metadata exists as keys in the
18  * various btrees. There are only a small number of btrees, they're not
19  * sharded - we have one btree for extents, another for inodes, et cetera.
20  *
21  * SUPERBLOCK:
22  *
23  * The superblock contains the location of the journal, the list of devices in
24  * the filesystem, and in general any metadata we need in order to decide
25  * whether we can start a filesystem or prior to reading the journal/btree
26  * roots.
27  *
28  * The superblock is extensible, and most of the contents of the superblock are
29  * in variable length, type tagged fields; see struct bch_sb_field.
30  *
31  * Backup superblocks do not reside in a fixed location; also, superblocks do
32  * not have a fixed size. To locate backup superblocks we have struct
33  * bch_sb_layout; we store a copy of this inside every superblock, and also
34  * before the first superblock.
35  *
36  * JOURNAL:
37  *
38  * The journal primarily records btree updates in the order they occurred;
39  * journal replay consists of just iterating over all the keys in the open
40  * journal entries and re-inserting them into the btrees.
41  *
42  * The journal also contains entry types for the btree roots, and blacklisted
43  * journal sequence numbers (see journal_seq_blacklist.c).
44  *
45  * BTREE:
46  *
47  * bcachefs btrees are copy on write b+ trees, where nodes are big (typically
48  * 128k-256k) and log structured. We use struct btree_node for writing the first
49  * entry in a given node (offset 0), and struct btree_node_entry for all
50  * subsequent writes.
51  *
52  * After the header, btree node entries contain a list of keys in sorted order.
53  * Values are stored inline with the keys; since values are variable length (and
54  * keys effectively are variable length too, due to packing) we can't do random
55  * access without building up additional in memory tables in the btree node read
56  * path.
57  *
58  * BTREE KEYS (struct bkey):
59  *
60  * The various btrees share a common format for the key - so as to avoid
61  * switching in fastpath lookup/comparison code - but define their own
62  * structures for the key values.
63  *
64  * The size of a key/value pair is stored as a u8 in units of u64s, so the max
65  * size is just under 2k. The common part also contains a type tag for the
66  * value, and a format field indicating whether the key is packed or not (and
67  * also meant to allow adding new key fields in the future, if desired).
68  *
69  * bkeys, when stored within a btree node, may also be packed. In that case, the
70  * bkey_format in that node is used to unpack it. Packed bkeys mean that we can
71  * be generous with field sizes in the common part of the key format (64 bit
72  * inode number, 64 bit offset, 96 bit version field, etc.) for negligible cost.
73  */
74 
75 #include <asm/types.h>
76 #include <asm/byteorder.h>
77 #include <linux/kernel.h>
78 #include <linux/uuid.h>
79 #include <uapi/linux/magic.h>
80 #include "vstructs.h"
81 
82 #ifdef __KERNEL__
83 typedef uuid_t __uuid_t;
84 #endif
85 
86 #define BITMASK(name, type, field, offset, end)				\
87 static const __maybe_unused unsigned	name##_OFFSET = offset;		\
88 static const __maybe_unused unsigned	name##_BITS = (end - offset);	\
89 									\
90 static inline __u64 name(const type *k)					\
91 {									\
92 	return (k->field >> offset) & ~(~0ULL << (end - offset));	\
93 }									\
94 									\
95 static inline void SET_##name(type *k, __u64 v)				\
96 {									\
97 	k->field &= ~(~(~0ULL << (end - offset)) << offset);		\
98 	k->field |= (v & ~(~0ULL << (end - offset))) << offset;		\
99 }
100 
101 #define LE_BITMASK(_bits, name, type, field, offset, end)		\
102 static const __maybe_unused unsigned	name##_OFFSET = offset;		\
103 static const __maybe_unused unsigned	name##_BITS = (end - offset);	\
104 static const __maybe_unused __u##_bits	name##_MAX = (1ULL << (end - offset)) - 1;\
105 									\
106 static inline __u64 name(const type *k)					\
107 {									\
108 	return (__le##_bits##_to_cpu(k->field) >> offset) &		\
109 		~(~0ULL << (end - offset));				\
110 }									\
111 									\
112 static inline void SET_##name(type *k, __u64 v)				\
113 {									\
114 	__u##_bits new = __le##_bits##_to_cpu(k->field);		\
115 									\
116 	new &= ~(~(~0ULL << (end - offset)) << offset);			\
117 	new |= (v & ~(~0ULL << (end - offset))) << offset;		\
118 	k->field = __cpu_to_le##_bits(new);				\
119 }
120 
121 #define LE16_BITMASK(n, t, f, o, e)	LE_BITMASK(16, n, t, f, o, e)
122 #define LE32_BITMASK(n, t, f, o, e)	LE_BITMASK(32, n, t, f, o, e)
123 #define LE64_BITMASK(n, t, f, o, e)	LE_BITMASK(64, n, t, f, o, e)
124 
125 struct bkey_format {
126 	__u8		key_u64s;
127 	__u8		nr_fields;
128 	/* One unused slot for now: */
129 	__u8		bits_per_field[6];
130 	__le64		field_offset[6];
131 };
132 
133 /* Btree keys - all units are in sectors */
134 
135 struct bpos {
136 	/*
137 	 * Word order matches machine byte order - btree code treats a bpos as a
138 	 * single large integer, for search/comparison purposes
139 	 *
140 	 * Note that wherever a bpos is embedded in another on disk data
141 	 * structure, it has to be byte swabbed when reading in metadata that
142 	 * wasn't written in native endian order:
143 	 */
144 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
145 	__u32		snapshot;
146 	__u64		offset;
147 	__u64		inode;
148 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
149 	__u64		inode;
150 	__u64		offset;		/* Points to end of extent - sectors */
151 	__u32		snapshot;
152 #else
153 #error edit for your odd byteorder.
154 #endif
155 } __packed
156 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
157 __aligned(4)
158 #endif
159 ;
160 
161 #define KEY_INODE_MAX			((__u64)~0ULL)
162 #define KEY_OFFSET_MAX			((__u64)~0ULL)
163 #define KEY_SNAPSHOT_MAX		((__u32)~0U)
164 #define KEY_SIZE_MAX			((__u32)~0U)
165 
166 static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
167 {
168 	return (struct bpos) {
169 		.inode		= inode,
170 		.offset		= offset,
171 		.snapshot	= snapshot,
172 	};
173 }
174 
175 #define POS_MIN				SPOS(0, 0, 0)
176 #define POS_MAX				SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
177 #define SPOS_MAX			SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
178 #define POS(_inode, _offset)		SPOS(_inode, _offset, 0)
179 
180 /* Empty placeholder struct, for container_of() */
181 struct bch_val {
182 	__u64		__nothing[0];
183 };
184 
185 struct bversion {
186 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
187 	__u64		lo;
188 	__u32		hi;
189 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
190 	__u32		hi;
191 	__u64		lo;
192 #endif
193 } __packed
194 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
195 __aligned(4)
196 #endif
197 ;
198 
199 struct bkey {
200 	/* Size of combined key and value, in u64s */
201 	__u8		u64s;
202 
203 	/* Format of key (0 for format local to btree node) */
204 #if defined(__LITTLE_ENDIAN_BITFIELD)
205 	__u8		format:7,
206 			needs_whiteout:1;
207 #elif defined (__BIG_ENDIAN_BITFIELD)
208 	__u8		needs_whiteout:1,
209 			format:7;
210 #else
211 #error edit for your odd byteorder.
212 #endif
213 
214 	/* Type of the value */
215 	__u8		type;
216 
217 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
218 	__u8		pad[1];
219 
220 	struct bversion	version;
221 	__u32		size;		/* extent size, in sectors */
222 	struct bpos	p;
223 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
224 	struct bpos	p;
225 	__u32		size;		/* extent size, in sectors */
226 	struct bversion	version;
227 
228 	__u8		pad[1];
229 #endif
230 } __packed
231 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
232 /*
233  * The big-endian version of bkey can't be compiled by rustc with the "aligned"
234  * attr since it doesn't allow types to have both "packed" and "aligned" attrs.
235  * So for Rust compatibility, don't include this. It can be included in the LE
236  * version because the "packed" attr is redundant in that case.
237  *
238  * History: (quoting Kent)
239  *
240  * Specifically, when i was designing bkey, I wanted the header to be no
241  * bigger than necessary so that bkey_packed could use the rest. That means that
242  * decently offten extent keys will fit into only 8 bytes, instead of spilling over
243  * to 16.
244  *
245  * But packed_bkey treats the part after the header - the packed section -
246  * as a single multi word, variable length integer. And bkey, the unpacked
247  * version, is just a special case version of a bkey_packed; all the packed
248  * bkey code will work on keys in any packed format, the in-memory
249  * representation of an unpacked key also is just one type of packed key...
250  *
251  * So that constrains the key part of a bkig endian bkey to start right
252  * after the header.
253  *
254  * If we ever do a bkey_v2 and need to expand the hedaer by another byte for
255  * some reason - that will clean up this wart.
256  */
257 __aligned(8)
258 #endif
259 ;
260 
261 struct bkey_packed {
262 	__u64		_data[0];
263 
264 	/* Size of combined key and value, in u64s */
265 	__u8		u64s;
266 
267 	/* Format of key (0 for format local to btree node) */
268 
269 	/*
270 	 * XXX: next incompat on disk format change, switch format and
271 	 * needs_whiteout - bkey_packed() will be cheaper if format is the high
272 	 * bits of the bitfield
273 	 */
274 #if defined(__LITTLE_ENDIAN_BITFIELD)
275 	__u8		format:7,
276 			needs_whiteout:1;
277 #elif defined (__BIG_ENDIAN_BITFIELD)
278 	__u8		needs_whiteout:1,
279 			format:7;
280 #endif
281 
282 	/* Type of the value */
283 	__u8		type;
284 	__u8		key_start[0];
285 
286 	/*
287 	 * We copy bkeys with struct assignment in various places, and while
288 	 * that shouldn't be done with packed bkeys we can't disallow it in C,
289 	 * and it's legal to cast a bkey to a bkey_packed  - so padding it out
290 	 * to the same size as struct bkey should hopefully be safest.
291 	 */
292 	__u8		pad[sizeof(struct bkey) - 3];
293 } __packed __aligned(8);
294 
295 typedef struct {
296 	__le64			lo;
297 	__le64			hi;
298 } bch_le128;
299 
300 #define BKEY_U64s			(sizeof(struct bkey) / sizeof(__u64))
301 #define BKEY_U64s_MAX			U8_MAX
302 #define BKEY_VAL_U64s_MAX		(BKEY_U64s_MAX - BKEY_U64s)
303 
304 #define KEY_PACKED_BITS_START		24
305 
306 #define KEY_FORMAT_LOCAL_BTREE		0
307 #define KEY_FORMAT_CURRENT		1
308 
309 enum bch_bkey_fields {
310 	BKEY_FIELD_INODE,
311 	BKEY_FIELD_OFFSET,
312 	BKEY_FIELD_SNAPSHOT,
313 	BKEY_FIELD_SIZE,
314 	BKEY_FIELD_VERSION_HI,
315 	BKEY_FIELD_VERSION_LO,
316 	BKEY_NR_FIELDS,
317 };
318 
319 #define bkey_format_field(name, field)					\
320 	[BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8)
321 
322 #define BKEY_FORMAT_CURRENT						\
323 ((struct bkey_format) {							\
324 	.key_u64s	= BKEY_U64s,					\
325 	.nr_fields	= BKEY_NR_FIELDS,				\
326 	.bits_per_field = {						\
327 		bkey_format_field(INODE,	p.inode),		\
328 		bkey_format_field(OFFSET,	p.offset),		\
329 		bkey_format_field(SNAPSHOT,	p.snapshot),		\
330 		bkey_format_field(SIZE,		size),			\
331 		bkey_format_field(VERSION_HI,	version.hi),		\
332 		bkey_format_field(VERSION_LO,	version.lo),		\
333 	},								\
334 })
335 
336 /* bkey with inline value */
337 struct bkey_i {
338 	__u64			_data[0];
339 
340 	struct bkey	k;
341 	struct bch_val	v;
342 };
343 
344 #define POS_KEY(_pos)							\
345 ((struct bkey) {							\
346 	.u64s		= BKEY_U64s,					\
347 	.format		= KEY_FORMAT_CURRENT,				\
348 	.p		= _pos,						\
349 })
350 
351 #define KEY(_inode, _offset, _size)					\
352 ((struct bkey) {							\
353 	.u64s		= BKEY_U64s,					\
354 	.format		= KEY_FORMAT_CURRENT,				\
355 	.p		= POS(_inode, _offset),				\
356 	.size		= _size,					\
357 })
358 
359 static inline void bkey_init(struct bkey *k)
360 {
361 	*k = KEY(0, 0, 0);
362 }
363 
364 #define bkey_bytes(_k)		((_k)->u64s * sizeof(__u64))
365 
366 #define __BKEY_PADDED(key, pad)					\
367 	struct bkey_i key; __u64 key ## _pad[pad]
368 
369 /*
370  * - DELETED keys are used internally to mark keys that should be ignored but
371  *   override keys in composition order.  Their version number is ignored.
372  *
373  * - DISCARDED keys indicate that the data is all 0s because it has been
374  *   discarded. DISCARDs may have a version; if the version is nonzero the key
375  *   will be persistent, otherwise the key will be dropped whenever the btree
376  *   node is rewritten (like DELETED keys).
377  *
378  * - ERROR: any read of the data returns a read error, as the data was lost due
379  *   to a failing device. Like DISCARDED keys, they can be removed (overridden)
380  *   by new writes or cluster-wide GC. Node repair can also overwrite them with
381  *   the same or a more recent version number, but not with an older version
382  *   number.
383  *
384  * - WHITEOUT: for hash table btrees
385  */
386 #define BCH_BKEY_TYPES()				\
387 	x(deleted,		0)			\
388 	x(whiteout,		1)			\
389 	x(error,		2)			\
390 	x(cookie,		3)			\
391 	x(hash_whiteout,	4)			\
392 	x(btree_ptr,		5)			\
393 	x(extent,		6)			\
394 	x(reservation,		7)			\
395 	x(inode,		8)			\
396 	x(inode_generation,	9)			\
397 	x(dirent,		10)			\
398 	x(xattr,		11)			\
399 	x(alloc,		12)			\
400 	x(quota,		13)			\
401 	x(stripe,		14)			\
402 	x(reflink_p,		15)			\
403 	x(reflink_v,		16)			\
404 	x(inline_data,		17)			\
405 	x(btree_ptr_v2,		18)			\
406 	x(indirect_inline_data,	19)			\
407 	x(alloc_v2,		20)			\
408 	x(subvolume,		21)			\
409 	x(snapshot,		22)			\
410 	x(inode_v2,		23)			\
411 	x(alloc_v3,		24)			\
412 	x(set,			25)			\
413 	x(lru,			26)			\
414 	x(alloc_v4,		27)			\
415 	x(backpointer,		28)			\
416 	x(inode_v3,		29)			\
417 	x(bucket_gens,		30)			\
418 	x(snapshot_tree,	31)			\
419 	x(logged_op_truncate,	32)			\
420 	x(logged_op_finsert,	33)
421 
422 enum bch_bkey_type {
423 #define x(name, nr) KEY_TYPE_##name	= nr,
424 	BCH_BKEY_TYPES()
425 #undef x
426 	KEY_TYPE_MAX,
427 };
428 
429 struct bch_deleted {
430 	struct bch_val		v;
431 };
432 
433 struct bch_whiteout {
434 	struct bch_val		v;
435 };
436 
437 struct bch_error {
438 	struct bch_val		v;
439 };
440 
441 struct bch_cookie {
442 	struct bch_val		v;
443 	__le64			cookie;
444 };
445 
446 struct bch_hash_whiteout {
447 	struct bch_val		v;
448 };
449 
450 struct bch_set {
451 	struct bch_val		v;
452 };
453 
454 /* 128 bits, sufficient for cryptographic MACs: */
455 struct bch_csum {
456 	__le64			lo;
457 	__le64			hi;
458 } __packed __aligned(8);
459 
460 struct bch_backpointer {
461 	struct bch_val		v;
462 	__u8			btree_id;
463 	__u8			level;
464 	__u8			data_type;
465 	__u64			bucket_offset:40;
466 	__u32			bucket_len;
467 	struct bpos		pos;
468 } __packed __aligned(8);
469 
470 /* LRU btree: */
471 
472 struct bch_lru {
473 	struct bch_val		v;
474 	__le64			idx;
475 } __packed __aligned(8);
476 
477 #define LRU_ID_STRIPES		(1U << 16)
478 
479 #define LRU_TIME_BITS	48
480 #define LRU_TIME_MAX	((1ULL << LRU_TIME_BITS) - 1)
481 
482 /* Optional/variable size superblock sections: */
483 
484 struct bch_sb_field {
485 	__u64			_data[0];
486 	__le32			u64s;
487 	__le32			type;
488 };
489 
490 #define BCH_SB_FIELDS()				\
491 	x(journal,			0)	\
492 	x(members_v1,			1)	\
493 	x(crypt,			2)	\
494 	x(replicas_v0,			3)	\
495 	x(quota,			4)	\
496 	x(disk_groups,			5)	\
497 	x(clean,			6)	\
498 	x(replicas,			7)	\
499 	x(journal_seq_blacklist,	8)	\
500 	x(journal_v2,			9)	\
501 	x(counters,			10)	\
502 	x(members_v2,			11)	\
503 	x(errors,			12)	\
504 	x(ext,				13)	\
505 	x(downgrade,			14)
506 
507 #include "alloc_background_format.h"
508 #include "extents_format.h"
509 #include "ec_format.h"
510 #include "dirent_format.h"
511 #include "disk_groups_format.h"
512 #include "inode_format.h"
513 #include "journal_seq_blacklist_format.h"
514 #include "logged_ops_format.h"
515 #include "quota_format.h"
516 #include "reflink_format.h"
517 #include "replicas_format.h"
518 #include "snapshot_format.h"
519 #include "subvolume_format.h"
520 #include "sb-counters_format.h"
521 #include "sb-downgrade_format.h"
522 #include "sb-errors_format.h"
523 #include "sb-members_format.h"
524 #include "xattr_format.h"
525 
526 enum bch_sb_field_type {
527 #define x(f, nr)	BCH_SB_FIELD_##f = nr,
528 	BCH_SB_FIELDS()
529 #undef x
530 	BCH_SB_FIELD_NR
531 };
532 
533 /*
534  * Most superblock fields are replicated in all device's superblocks - a few are
535  * not:
536  */
537 #define BCH_SINGLE_DEVICE_SB_FIELDS		\
538 	((1U << BCH_SB_FIELD_journal)|		\
539 	 (1U << BCH_SB_FIELD_journal_v2))
540 
541 /* BCH_SB_FIELD_journal: */
542 
543 struct bch_sb_field_journal {
544 	struct bch_sb_field	field;
545 	__le64			buckets[];
546 };
547 
548 struct bch_sb_field_journal_v2 {
549 	struct bch_sb_field	field;
550 
551 	struct bch_sb_field_journal_v2_entry {
552 		__le64		start;
553 		__le64		nr;
554 	}			d[];
555 };
556 
557 /* BCH_SB_FIELD_crypt: */
558 
559 struct nonce {
560 	__le32			d[4];
561 };
562 
563 struct bch_key {
564 	__le64			key[4];
565 };
566 
567 #define BCH_KEY_MAGIC					\
568 	(((__u64) 'b' <<  0)|((__u64) 'c' <<  8)|		\
569 	 ((__u64) 'h' << 16)|((__u64) '*' << 24)|		\
570 	 ((__u64) '*' << 32)|((__u64) 'k' << 40)|		\
571 	 ((__u64) 'e' << 48)|((__u64) 'y' << 56))
572 
573 struct bch_encrypted_key {
574 	__le64			magic;
575 	struct bch_key		key;
576 };
577 
578 /*
579  * If this field is present in the superblock, it stores an encryption key which
580  * is used encrypt all other data/metadata. The key will normally be encrypted
581  * with the key userspace provides, but if encryption has been turned off we'll
582  * just store the master key unencrypted in the superblock so we can access the
583  * previously encrypted data.
584  */
585 struct bch_sb_field_crypt {
586 	struct bch_sb_field	field;
587 
588 	__le64			flags;
589 	__le64			kdf_flags;
590 	struct bch_encrypted_key key;
591 };
592 
593 LE64_BITMASK(BCH_CRYPT_KDF_TYPE,	struct bch_sb_field_crypt, flags, 0, 4);
594 
595 enum bch_kdf_types {
596 	BCH_KDF_SCRYPT		= 0,
597 	BCH_KDF_NR		= 1,
598 };
599 
600 /* stored as base 2 log of scrypt params: */
601 LE64_BITMASK(BCH_KDF_SCRYPT_N,	struct bch_sb_field_crypt, kdf_flags,  0, 16);
602 LE64_BITMASK(BCH_KDF_SCRYPT_R,	struct bch_sb_field_crypt, kdf_flags, 16, 32);
603 LE64_BITMASK(BCH_KDF_SCRYPT_P,	struct bch_sb_field_crypt, kdf_flags, 32, 48);
604 
605 #define BCH_DATA_TYPES()		\
606 	x(free,		0)		\
607 	x(sb,		1)		\
608 	x(journal,	2)		\
609 	x(btree,	3)		\
610 	x(user,		4)		\
611 	x(cached,	5)		\
612 	x(parity,	6)		\
613 	x(stripe,	7)		\
614 	x(need_gc_gens,	8)		\
615 	x(need_discard,	9)
616 
617 enum bch_data_type {
618 #define x(t, n) BCH_DATA_##t,
619 	BCH_DATA_TYPES()
620 #undef x
621 	BCH_DATA_NR
622 };
623 
624 static inline bool data_type_is_empty(enum bch_data_type type)
625 {
626 	switch (type) {
627 	case BCH_DATA_free:
628 	case BCH_DATA_need_gc_gens:
629 	case BCH_DATA_need_discard:
630 		return true;
631 	default:
632 		return false;
633 	}
634 }
635 
636 static inline bool data_type_is_hidden(enum bch_data_type type)
637 {
638 	switch (type) {
639 	case BCH_DATA_sb:
640 	case BCH_DATA_journal:
641 		return true;
642 	default:
643 		return false;
644 	}
645 }
646 
647 /*
648  * On clean shutdown, store btree roots and current journal sequence number in
649  * the superblock:
650  */
651 struct jset_entry {
652 	__le16			u64s;
653 	__u8			btree_id;
654 	__u8			level;
655 	__u8			type; /* designates what this jset holds */
656 	__u8			pad[3];
657 
658 	struct bkey_i		start[0];
659 	__u64			_data[];
660 };
661 
662 struct bch_sb_field_clean {
663 	struct bch_sb_field	field;
664 
665 	__le32			flags;
666 	__le16			_read_clock; /* no longer used */
667 	__le16			_write_clock;
668 	__le64			journal_seq;
669 
670 	struct jset_entry	start[0];
671 	__u64			_data[];
672 };
673 
674 struct bch_sb_field_ext {
675 	struct bch_sb_field	field;
676 	__le64			recovery_passes_required[2];
677 	__le64			errors_silent[8];
678 	__le64			btrees_lost_data;
679 };
680 
681 /* Superblock: */
682 
683 /*
684  * New versioning scheme:
685  * One common version number for all on disk data structures - superblock, btree
686  * nodes, journal entries
687  */
688 #define BCH_VERSION_MAJOR(_v)		((__u16) ((_v) >> 10))
689 #define BCH_VERSION_MINOR(_v)		((__u16) ((_v) & ~(~0U << 10)))
690 #define BCH_VERSION(_major, _minor)	(((_major) << 10)|(_minor) << 0)
691 
692 /*
693  * field 1:		version name
694  * field 2:		BCH_VERSION(major, minor)
695  * field 3:		recovery passess required on upgrade
696  */
697 #define BCH_METADATA_VERSIONS()						\
698 	x(bkey_renumber,		BCH_VERSION(0, 10))		\
699 	x(inode_btree_change,		BCH_VERSION(0, 11))		\
700 	x(snapshot,			BCH_VERSION(0, 12))		\
701 	x(inode_backpointers,		BCH_VERSION(0, 13))		\
702 	x(btree_ptr_sectors_written,	BCH_VERSION(0, 14))		\
703 	x(snapshot_2,			BCH_VERSION(0, 15))		\
704 	x(reflink_p_fix,		BCH_VERSION(0, 16))		\
705 	x(subvol_dirent,		BCH_VERSION(0, 17))		\
706 	x(inode_v2,			BCH_VERSION(0, 18))		\
707 	x(freespace,			BCH_VERSION(0, 19))		\
708 	x(alloc_v4,			BCH_VERSION(0, 20))		\
709 	x(new_data_types,		BCH_VERSION(0, 21))		\
710 	x(backpointers,			BCH_VERSION(0, 22))		\
711 	x(inode_v3,			BCH_VERSION(0, 23))		\
712 	x(unwritten_extents,		BCH_VERSION(0, 24))		\
713 	x(bucket_gens,			BCH_VERSION(0, 25))		\
714 	x(lru_v2,			BCH_VERSION(0, 26))		\
715 	x(fragmentation_lru,		BCH_VERSION(0, 27))		\
716 	x(no_bps_in_alloc_keys,		BCH_VERSION(0, 28))		\
717 	x(snapshot_trees,		BCH_VERSION(0, 29))		\
718 	x(major_minor,			BCH_VERSION(1,  0))		\
719 	x(snapshot_skiplists,		BCH_VERSION(1,  1))		\
720 	x(deleted_inodes,		BCH_VERSION(1,  2))		\
721 	x(rebalance_work,		BCH_VERSION(1,  3))		\
722 	x(member_seq,			BCH_VERSION(1,  4))		\
723 	x(subvolume_fs_parent,		BCH_VERSION(1,  5))		\
724 	x(btree_subvolume_children,	BCH_VERSION(1,  6))		\
725 	x(mi_btree_bitmap,		BCH_VERSION(1,  7))
726 
727 enum bcachefs_metadata_version {
728 	bcachefs_metadata_version_min = 9,
729 #define x(t, n)	bcachefs_metadata_version_##t = n,
730 	BCH_METADATA_VERSIONS()
731 #undef x
732 	bcachefs_metadata_version_max
733 };
734 
735 static const __maybe_unused
736 unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_rebalance_work;
737 
738 #define bcachefs_metadata_version_current	(bcachefs_metadata_version_max - 1)
739 
740 #define BCH_SB_SECTOR			8
741 
742 #define BCH_SB_LAYOUT_SIZE_BITS_MAX	16 /* 32 MB */
743 
744 struct bch_sb_layout {
745 	__uuid_t		magic;	/* bcachefs superblock UUID */
746 	__u8			layout_type;
747 	__u8			sb_max_size_bits; /* base 2 of 512 byte sectors */
748 	__u8			nr_superblocks;
749 	__u8			pad[5];
750 	__le64			sb_offset[61];
751 } __packed __aligned(8);
752 
753 #define BCH_SB_LAYOUT_SECTOR	7
754 
755 /*
756  * @offset	- sector where this sb was written
757  * @version	- on disk format version
758  * @version_min	- Oldest metadata version this filesystem contains; so we can
759  *		  safely drop compatibility code and refuse to mount filesystems
760  *		  we'd need it for
761  * @magic	- identifies as a bcachefs superblock (BCHFS_MAGIC)
762  * @seq		- incremented each time superblock is written
763  * @uuid	- used for generating various magic numbers and identifying
764  *                member devices, never changes
765  * @user_uuid	- user visible UUID, may be changed
766  * @label	- filesystem label
767  * @seq		- identifies most recent superblock, incremented each time
768  *		  superblock is written
769  * @features	- enabled incompatible features
770  */
771 struct bch_sb {
772 	struct bch_csum		csum;
773 	__le16			version;
774 	__le16			version_min;
775 	__le16			pad[2];
776 	__uuid_t		magic;
777 	__uuid_t		uuid;
778 	__uuid_t		user_uuid;
779 	__u8			label[BCH_SB_LABEL_SIZE];
780 	__le64			offset;
781 	__le64			seq;
782 
783 	__le16			block_size;
784 	__u8			dev_idx;
785 	__u8			nr_devices;
786 	__le32			u64s;
787 
788 	__le64			time_base_lo;
789 	__le32			time_base_hi;
790 	__le32			time_precision;
791 
792 	__le64			flags[7];
793 	__le64			write_time;
794 	__le64			features[2];
795 	__le64			compat[2];
796 
797 	struct bch_sb_layout	layout;
798 
799 	struct bch_sb_field	start[0];
800 	__le64			_data[];
801 } __packed __aligned(8);
802 
803 /*
804  * Flags:
805  * BCH_SB_INITALIZED	- set on first mount
806  * BCH_SB_CLEAN		- did we shut down cleanly? Just a hint, doesn't affect
807  *			  behaviour of mount/recovery path:
808  * BCH_SB_INODE_32BIT	- limit inode numbers to 32 bits
809  * BCH_SB_128_BIT_MACS	- 128 bit macs instead of 80
810  * BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides
811  *			   DATA/META_CSUM_TYPE. Also indicates encryption
812  *			   algorithm in use, if/when we get more than one
813  */
814 
815 LE16_BITMASK(BCH_SB_BLOCK_SIZE,		struct bch_sb, block_size, 0, 16);
816 
817 LE64_BITMASK(BCH_SB_INITIALIZED,	struct bch_sb, flags[0],  0,  1);
818 LE64_BITMASK(BCH_SB_CLEAN,		struct bch_sb, flags[0],  1,  2);
819 LE64_BITMASK(BCH_SB_CSUM_TYPE,		struct bch_sb, flags[0],  2,  8);
820 LE64_BITMASK(BCH_SB_ERROR_ACTION,	struct bch_sb, flags[0],  8, 12);
821 
822 LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE,	struct bch_sb, flags[0], 12, 28);
823 
824 LE64_BITMASK(BCH_SB_GC_RESERVE,		struct bch_sb, flags[0], 28, 33);
825 LE64_BITMASK(BCH_SB_ROOT_RESERVE,	struct bch_sb, flags[0], 33, 40);
826 
827 LE64_BITMASK(BCH_SB_META_CSUM_TYPE,	struct bch_sb, flags[0], 40, 44);
828 LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE,	struct bch_sb, flags[0], 44, 48);
829 
830 LE64_BITMASK(BCH_SB_META_REPLICAS_WANT,	struct bch_sb, flags[0], 48, 52);
831 LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT,	struct bch_sb, flags[0], 52, 56);
832 
833 LE64_BITMASK(BCH_SB_POSIX_ACL,		struct bch_sb, flags[0], 56, 57);
834 LE64_BITMASK(BCH_SB_USRQUOTA,		struct bch_sb, flags[0], 57, 58);
835 LE64_BITMASK(BCH_SB_GRPQUOTA,		struct bch_sb, flags[0], 58, 59);
836 LE64_BITMASK(BCH_SB_PRJQUOTA,		struct bch_sb, flags[0], 59, 60);
837 
838 LE64_BITMASK(BCH_SB_HAS_ERRORS,		struct bch_sb, flags[0], 60, 61);
839 LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
840 
841 LE64_BITMASK(BCH_SB_BIG_ENDIAN,		struct bch_sb, flags[0], 62, 63);
842 
843 LE64_BITMASK(BCH_SB_STR_HASH_TYPE,	struct bch_sb, flags[1],  0,  4);
844 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_LO,struct bch_sb, flags[1],  4,  8);
845 LE64_BITMASK(BCH_SB_INODE_32BIT,	struct bch_sb, flags[1],  8,  9);
846 
847 LE64_BITMASK(BCH_SB_128_BIT_MACS,	struct bch_sb, flags[1],  9, 10);
848 LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE,	struct bch_sb, flags[1], 10, 14);
849 
850 /*
851  * Max size of an extent that may require bouncing to read or write
852  * (checksummed, compressed): 64k
853  */
854 LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
855 					struct bch_sb, flags[1], 14, 20);
856 
857 LE64_BITMASK(BCH_SB_META_REPLICAS_REQ,	struct bch_sb, flags[1], 20, 24);
858 LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ,	struct bch_sb, flags[1], 24, 28);
859 
860 LE64_BITMASK(BCH_SB_PROMOTE_TARGET,	struct bch_sb, flags[1], 28, 40);
861 LE64_BITMASK(BCH_SB_FOREGROUND_TARGET,	struct bch_sb, flags[1], 40, 52);
862 LE64_BITMASK(BCH_SB_BACKGROUND_TARGET,	struct bch_sb, flags[1], 52, 64);
863 
864 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO,
865 					struct bch_sb, flags[2],  0,  4);
866 LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES,	struct bch_sb, flags[2],  4, 64);
867 
868 LE64_BITMASK(BCH_SB_ERASURE_CODE,	struct bch_sb, flags[3],  0, 16);
869 LE64_BITMASK(BCH_SB_METADATA_TARGET,	struct bch_sb, flags[3], 16, 28);
870 LE64_BITMASK(BCH_SB_SHARD_INUMS,	struct bch_sb, flags[3], 28, 29);
871 LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
872 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
873 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
874 LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
875 LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
876 LE64_BITMASK(BCH_SB_NOCOW,		struct bch_sb, flags[4], 33, 34);
877 LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE,	struct bch_sb, flags[4], 34, 54);
878 LE64_BITMASK(BCH_SB_VERSION_UPGRADE,	struct bch_sb, flags[4], 54, 56);
879 
880 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_HI,struct bch_sb, flags[4], 56, 60);
881 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI,
882 					struct bch_sb, flags[4], 60, 64);
883 
884 LE64_BITMASK(BCH_SB_VERSION_UPGRADE_COMPLETE,
885 					struct bch_sb, flags[5],  0, 16);
886 
887 static inline __u64 BCH_SB_COMPRESSION_TYPE(const struct bch_sb *sb)
888 {
889 	return BCH_SB_COMPRESSION_TYPE_LO(sb) | (BCH_SB_COMPRESSION_TYPE_HI(sb) << 4);
890 }
891 
892 static inline void SET_BCH_SB_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
893 {
894 	SET_BCH_SB_COMPRESSION_TYPE_LO(sb, v);
895 	SET_BCH_SB_COMPRESSION_TYPE_HI(sb, v >> 4);
896 }
897 
898 static inline __u64 BCH_SB_BACKGROUND_COMPRESSION_TYPE(const struct bch_sb *sb)
899 {
900 	return BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb) |
901 		(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb) << 4);
902 }
903 
904 static inline void SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
905 {
906 	SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb, v);
907 	SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb, v >> 4);
908 }
909 
910 /*
911  * Features:
912  *
913  * journal_seq_blacklist_v3:	gates BCH_SB_FIELD_journal_seq_blacklist
914  * reflink:			gates KEY_TYPE_reflink
915  * inline_data:			gates KEY_TYPE_inline_data
916  * new_siphash:			gates BCH_STR_HASH_siphash
917  * new_extent_overwrite:	gates BTREE_NODE_NEW_EXTENT_OVERWRITE
918  */
919 #define BCH_SB_FEATURES()			\
920 	x(lz4,				0)	\
921 	x(gzip,				1)	\
922 	x(zstd,				2)	\
923 	x(atomic_nlink,			3)	\
924 	x(ec,				4)	\
925 	x(journal_seq_blacklist_v3,	5)	\
926 	x(reflink,			6)	\
927 	x(new_siphash,			7)	\
928 	x(inline_data,			8)	\
929 	x(new_extent_overwrite,		9)	\
930 	x(incompressible,		10)	\
931 	x(btree_ptr_v2,			11)	\
932 	x(extents_above_btree_updates,	12)	\
933 	x(btree_updates_journalled,	13)	\
934 	x(reflink_inline_data,		14)	\
935 	x(new_varint,			15)	\
936 	x(journal_no_flush,		16)	\
937 	x(alloc_v2,			17)	\
938 	x(extents_across_btree_nodes,	18)
939 
940 #define BCH_SB_FEATURES_ALWAYS				\
941 	((1ULL << BCH_FEATURE_new_extent_overwrite)|	\
942 	 (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
943 	 (1ULL << BCH_FEATURE_btree_updates_journalled)|\
944 	 (1ULL << BCH_FEATURE_alloc_v2)|\
945 	 (1ULL << BCH_FEATURE_extents_across_btree_nodes))
946 
947 #define BCH_SB_FEATURES_ALL				\
948 	(BCH_SB_FEATURES_ALWAYS|			\
949 	 (1ULL << BCH_FEATURE_new_siphash)|		\
950 	 (1ULL << BCH_FEATURE_btree_ptr_v2)|		\
951 	 (1ULL << BCH_FEATURE_new_varint)|		\
952 	 (1ULL << BCH_FEATURE_journal_no_flush))
953 
954 enum bch_sb_feature {
955 #define x(f, n) BCH_FEATURE_##f,
956 	BCH_SB_FEATURES()
957 #undef x
958 	BCH_FEATURE_NR,
959 };
960 
961 #define BCH_SB_COMPAT()					\
962 	x(alloc_info,				0)	\
963 	x(alloc_metadata,			1)	\
964 	x(extents_above_btree_updates_done,	2)	\
965 	x(bformat_overflow_done,		3)
966 
967 enum bch_sb_compat {
968 #define x(f, n) BCH_COMPAT_##f,
969 	BCH_SB_COMPAT()
970 #undef x
971 	BCH_COMPAT_NR,
972 };
973 
974 /* options: */
975 
976 #define BCH_VERSION_UPGRADE_OPTS()	\
977 	x(compatible,		0)	\
978 	x(incompatible,		1)	\
979 	x(none,			2)
980 
981 enum bch_version_upgrade_opts {
982 #define x(t, n) BCH_VERSION_UPGRADE_##t = n,
983 	BCH_VERSION_UPGRADE_OPTS()
984 #undef x
985 };
986 
987 #define BCH_REPLICAS_MAX		4U
988 
989 #define BCH_BKEY_PTRS_MAX		16U
990 
991 #define BCH_ERROR_ACTIONS()		\
992 	x(continue,		0)	\
993 	x(fix_safe,		1)	\
994 	x(panic,		2)	\
995 	x(ro,			3)
996 
997 enum bch_error_actions {
998 #define x(t, n) BCH_ON_ERROR_##t = n,
999 	BCH_ERROR_ACTIONS()
1000 #undef x
1001 	BCH_ON_ERROR_NR
1002 };
1003 
1004 #define BCH_STR_HASH_TYPES()		\
1005 	x(crc32c,		0)	\
1006 	x(crc64,		1)	\
1007 	x(siphash_old,		2)	\
1008 	x(siphash,		3)
1009 
1010 enum bch_str_hash_type {
1011 #define x(t, n) BCH_STR_HASH_##t = n,
1012 	BCH_STR_HASH_TYPES()
1013 #undef x
1014 	BCH_STR_HASH_NR
1015 };
1016 
1017 #define BCH_STR_HASH_OPTS()		\
1018 	x(crc32c,		0)	\
1019 	x(crc64,		1)	\
1020 	x(siphash,		2)
1021 
1022 enum bch_str_hash_opts {
1023 #define x(t, n) BCH_STR_HASH_OPT_##t = n,
1024 	BCH_STR_HASH_OPTS()
1025 #undef x
1026 	BCH_STR_HASH_OPT_NR
1027 };
1028 
1029 #define BCH_CSUM_TYPES()			\
1030 	x(none,				0)	\
1031 	x(crc32c_nonzero,		1)	\
1032 	x(crc64_nonzero,		2)	\
1033 	x(chacha20_poly1305_80,		3)	\
1034 	x(chacha20_poly1305_128,	4)	\
1035 	x(crc32c,			5)	\
1036 	x(crc64,			6)	\
1037 	x(xxhash,			7)
1038 
1039 enum bch_csum_type {
1040 #define x(t, n) BCH_CSUM_##t = n,
1041 	BCH_CSUM_TYPES()
1042 #undef x
1043 	BCH_CSUM_NR
1044 };
1045 
1046 static const __maybe_unused unsigned bch_crc_bytes[] = {
1047 	[BCH_CSUM_none]				= 0,
1048 	[BCH_CSUM_crc32c_nonzero]		= 4,
1049 	[BCH_CSUM_crc32c]			= 4,
1050 	[BCH_CSUM_crc64_nonzero]		= 8,
1051 	[BCH_CSUM_crc64]			= 8,
1052 	[BCH_CSUM_xxhash]			= 8,
1053 	[BCH_CSUM_chacha20_poly1305_80]		= 10,
1054 	[BCH_CSUM_chacha20_poly1305_128]	= 16,
1055 };
1056 
1057 static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
1058 {
1059 	switch (type) {
1060 	case BCH_CSUM_chacha20_poly1305_80:
1061 	case BCH_CSUM_chacha20_poly1305_128:
1062 		return true;
1063 	default:
1064 		return false;
1065 	}
1066 }
1067 
1068 #define BCH_CSUM_OPTS()			\
1069 	x(none,			0)	\
1070 	x(crc32c,		1)	\
1071 	x(crc64,		2)	\
1072 	x(xxhash,		3)
1073 
1074 enum bch_csum_opts {
1075 #define x(t, n) BCH_CSUM_OPT_##t = n,
1076 	BCH_CSUM_OPTS()
1077 #undef x
1078 	BCH_CSUM_OPT_NR
1079 };
1080 
1081 #define BCH_COMPRESSION_TYPES()		\
1082 	x(none,			0)	\
1083 	x(lz4_old,		1)	\
1084 	x(gzip,			2)	\
1085 	x(lz4,			3)	\
1086 	x(zstd,			4)	\
1087 	x(incompressible,	5)
1088 
1089 enum bch_compression_type {
1090 #define x(t, n) BCH_COMPRESSION_TYPE_##t = n,
1091 	BCH_COMPRESSION_TYPES()
1092 #undef x
1093 	BCH_COMPRESSION_TYPE_NR
1094 };
1095 
1096 #define BCH_COMPRESSION_OPTS()		\
1097 	x(none,		0)		\
1098 	x(lz4,		1)		\
1099 	x(gzip,		2)		\
1100 	x(zstd,		3)
1101 
1102 enum bch_compression_opts {
1103 #define x(t, n) BCH_COMPRESSION_OPT_##t = n,
1104 	BCH_COMPRESSION_OPTS()
1105 #undef x
1106 	BCH_COMPRESSION_OPT_NR
1107 };
1108 
1109 /*
1110  * Magic numbers
1111  *
1112  * The various other data structures have their own magic numbers, which are
1113  * xored with the first part of the cache set's UUID
1114  */
1115 
1116 #define BCACHE_MAGIC							\
1117 	UUID_INIT(0xc68573f6, 0x4e1a, 0x45ca,				\
1118 		  0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81)
1119 #define BCHFS_MAGIC							\
1120 	UUID_INIT(0xc68573f6, 0x66ce, 0x90a9,				\
1121 		  0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
1122 
1123 #define BCACHEFS_STATFS_MAGIC		BCACHEFS_SUPER_MAGIC
1124 
1125 #define JSET_MAGIC		__cpu_to_le64(0x245235c1a3625032ULL)
1126 #define BSET_MAGIC		__cpu_to_le64(0x90135c78b99e07f5ULL)
1127 
1128 static inline __le64 __bch2_sb_magic(struct bch_sb *sb)
1129 {
1130 	__le64 ret;
1131 
1132 	memcpy(&ret, &sb->uuid, sizeof(ret));
1133 	return ret;
1134 }
1135 
1136 static inline __u64 __jset_magic(struct bch_sb *sb)
1137 {
1138 	return __le64_to_cpu(__bch2_sb_magic(sb) ^ JSET_MAGIC);
1139 }
1140 
1141 static inline __u64 __bset_magic(struct bch_sb *sb)
1142 {
1143 	return __le64_to_cpu(__bch2_sb_magic(sb) ^ BSET_MAGIC);
1144 }
1145 
1146 /* Journal */
1147 
1148 #define JSET_KEYS_U64s	(sizeof(struct jset_entry) / sizeof(__u64))
1149 
1150 #define BCH_JSET_ENTRY_TYPES()			\
1151 	x(btree_keys,		0)		\
1152 	x(btree_root,		1)		\
1153 	x(prio_ptrs,		2)		\
1154 	x(blacklist,		3)		\
1155 	x(blacklist_v2,		4)		\
1156 	x(usage,		5)		\
1157 	x(data_usage,		6)		\
1158 	x(clock,		7)		\
1159 	x(dev_usage,		8)		\
1160 	x(log,			9)		\
1161 	x(overwrite,		10)		\
1162 	x(write_buffer_keys,	11)		\
1163 	x(datetime,		12)
1164 
1165 enum bch_jset_entry_type {
1166 #define x(f, nr)	BCH_JSET_ENTRY_##f	= nr,
1167 	BCH_JSET_ENTRY_TYPES()
1168 #undef x
1169 	BCH_JSET_ENTRY_NR
1170 };
1171 
1172 static inline bool jset_entry_is_key(struct jset_entry *e)
1173 {
1174 	switch (e->type) {
1175 	case BCH_JSET_ENTRY_btree_keys:
1176 	case BCH_JSET_ENTRY_btree_root:
1177 	case BCH_JSET_ENTRY_overwrite:
1178 	case BCH_JSET_ENTRY_write_buffer_keys:
1179 		return true;
1180 	}
1181 
1182 	return false;
1183 }
1184 
1185 /*
1186  * Journal sequence numbers can be blacklisted: bsets record the max sequence
1187  * number of all the journal entries they contain updates for, so that on
1188  * recovery we can ignore those bsets that contain index updates newer that what
1189  * made it into the journal.
1190  *
1191  * This means that we can't reuse that journal_seq - we have to skip it, and
1192  * then record that we skipped it so that the next time we crash and recover we
1193  * don't think there was a missing journal entry.
1194  */
1195 struct jset_entry_blacklist {
1196 	struct jset_entry	entry;
1197 	__le64			seq;
1198 };
1199 
1200 struct jset_entry_blacklist_v2 {
1201 	struct jset_entry	entry;
1202 	__le64			start;
1203 	__le64			end;
1204 };
1205 
1206 #define BCH_FS_USAGE_TYPES()			\
1207 	x(reserved,		0)		\
1208 	x(inodes,		1)		\
1209 	x(key_version,		2)
1210 
1211 enum bch_fs_usage_type {
1212 #define x(f, nr)	BCH_FS_USAGE_##f	= nr,
1213 	BCH_FS_USAGE_TYPES()
1214 #undef x
1215 	BCH_FS_USAGE_NR
1216 };
1217 
1218 struct jset_entry_usage {
1219 	struct jset_entry	entry;
1220 	__le64			v;
1221 } __packed;
1222 
1223 struct jset_entry_data_usage {
1224 	struct jset_entry	entry;
1225 	__le64			v;
1226 	struct bch_replicas_entry_v1 r;
1227 } __packed;
1228 
1229 struct jset_entry_clock {
1230 	struct jset_entry	entry;
1231 	__u8			rw;
1232 	__u8			pad[7];
1233 	__le64			time;
1234 } __packed;
1235 
1236 struct jset_entry_dev_usage_type {
1237 	__le64			buckets;
1238 	__le64			sectors;
1239 	__le64			fragmented;
1240 } __packed;
1241 
1242 struct jset_entry_dev_usage {
1243 	struct jset_entry	entry;
1244 	__le32			dev;
1245 	__u32			pad;
1246 
1247 	__le64			_buckets_ec;		/* No longer used */
1248 	__le64			_buckets_unavailable;	/* No longer used */
1249 
1250 	struct jset_entry_dev_usage_type d[];
1251 };
1252 
1253 static inline unsigned jset_entry_dev_usage_nr_types(struct jset_entry_dev_usage *u)
1254 {
1255 	return (vstruct_bytes(&u->entry) - sizeof(struct jset_entry_dev_usage)) /
1256 		sizeof(struct jset_entry_dev_usage_type);
1257 }
1258 
1259 struct jset_entry_log {
1260 	struct jset_entry	entry;
1261 	u8			d[];
1262 } __packed __aligned(8);
1263 
1264 struct jset_entry_datetime {
1265 	struct jset_entry	entry;
1266 	__le64			seconds;
1267 } __packed __aligned(8);
1268 
1269 /*
1270  * On disk format for a journal entry:
1271  * seq is monotonically increasing; every journal entry has its own unique
1272  * sequence number.
1273  *
1274  * last_seq is the oldest journal entry that still has keys the btree hasn't
1275  * flushed to disk yet.
1276  *
1277  * version is for on disk format changes.
1278  */
1279 struct jset {
1280 	struct bch_csum		csum;
1281 
1282 	__le64			magic;
1283 	__le64			seq;
1284 	__le32			version;
1285 	__le32			flags;
1286 
1287 	__le32			u64s; /* size of d[] in u64s */
1288 
1289 	__u8			encrypted_start[0];
1290 
1291 	__le16			_read_clock; /* no longer used */
1292 	__le16			_write_clock;
1293 
1294 	/* Sequence number of oldest dirty journal entry */
1295 	__le64			last_seq;
1296 
1297 
1298 	struct jset_entry	start[0];
1299 	__u64			_data[];
1300 } __packed __aligned(8);
1301 
1302 LE32_BITMASK(JSET_CSUM_TYPE,	struct jset, flags, 0, 4);
1303 LE32_BITMASK(JSET_BIG_ENDIAN,	struct jset, flags, 4, 5);
1304 LE32_BITMASK(JSET_NO_FLUSH,	struct jset, flags, 5, 6);
1305 
1306 #define BCH_JOURNAL_BUCKETS_MIN		8
1307 
1308 /* Btree: */
1309 
1310 enum btree_id_flags {
1311 	BTREE_ID_EXTENTS	= BIT(0),
1312 	BTREE_ID_SNAPSHOTS	= BIT(1),
1313 	BTREE_ID_SNAPSHOT_FIELD	= BIT(2),
1314 	BTREE_ID_DATA		= BIT(3),
1315 };
1316 
1317 #define BCH_BTREE_IDS()								\
1318 	x(extents,		0,	BTREE_ID_EXTENTS|BTREE_ID_SNAPSHOTS|BTREE_ID_DATA,\
1319 	  BIT_ULL(KEY_TYPE_whiteout)|						\
1320 	  BIT_ULL(KEY_TYPE_error)|						\
1321 	  BIT_ULL(KEY_TYPE_cookie)|						\
1322 	  BIT_ULL(KEY_TYPE_extent)|						\
1323 	  BIT_ULL(KEY_TYPE_reservation)|					\
1324 	  BIT_ULL(KEY_TYPE_reflink_p)|						\
1325 	  BIT_ULL(KEY_TYPE_inline_data))					\
1326 	x(inodes,		1,	BTREE_ID_SNAPSHOTS,			\
1327 	  BIT_ULL(KEY_TYPE_whiteout)|						\
1328 	  BIT_ULL(KEY_TYPE_inode)|						\
1329 	  BIT_ULL(KEY_TYPE_inode_v2)|						\
1330 	  BIT_ULL(KEY_TYPE_inode_v3)|						\
1331 	  BIT_ULL(KEY_TYPE_inode_generation))					\
1332 	x(dirents,		2,	BTREE_ID_SNAPSHOTS,			\
1333 	  BIT_ULL(KEY_TYPE_whiteout)|						\
1334 	  BIT_ULL(KEY_TYPE_hash_whiteout)|					\
1335 	  BIT_ULL(KEY_TYPE_dirent))						\
1336 	x(xattrs,		3,	BTREE_ID_SNAPSHOTS,			\
1337 	  BIT_ULL(KEY_TYPE_whiteout)|						\
1338 	  BIT_ULL(KEY_TYPE_cookie)|						\
1339 	  BIT_ULL(KEY_TYPE_hash_whiteout)|					\
1340 	  BIT_ULL(KEY_TYPE_xattr))						\
1341 	x(alloc,		4,	0,					\
1342 	  BIT_ULL(KEY_TYPE_alloc)|						\
1343 	  BIT_ULL(KEY_TYPE_alloc_v2)|						\
1344 	  BIT_ULL(KEY_TYPE_alloc_v3)|						\
1345 	  BIT_ULL(KEY_TYPE_alloc_v4))						\
1346 	x(quotas,		5,	0,					\
1347 	  BIT_ULL(KEY_TYPE_quota))						\
1348 	x(stripes,		6,	0,					\
1349 	  BIT_ULL(KEY_TYPE_stripe))						\
1350 	x(reflink,		7,	BTREE_ID_EXTENTS|BTREE_ID_DATA,		\
1351 	  BIT_ULL(KEY_TYPE_reflink_v)|						\
1352 	  BIT_ULL(KEY_TYPE_indirect_inline_data)|				\
1353 	  BIT_ULL(KEY_TYPE_error))						\
1354 	x(subvolumes,		8,	0,					\
1355 	  BIT_ULL(KEY_TYPE_subvolume))						\
1356 	x(snapshots,		9,	0,					\
1357 	  BIT_ULL(KEY_TYPE_snapshot))						\
1358 	x(lru,			10,	0,					\
1359 	  BIT_ULL(KEY_TYPE_set))						\
1360 	x(freespace,		11,	BTREE_ID_EXTENTS,			\
1361 	  BIT_ULL(KEY_TYPE_set))						\
1362 	x(need_discard,		12,	0,					\
1363 	  BIT_ULL(KEY_TYPE_set))						\
1364 	x(backpointers,		13,	0,					\
1365 	  BIT_ULL(KEY_TYPE_backpointer))					\
1366 	x(bucket_gens,		14,	0,					\
1367 	  BIT_ULL(KEY_TYPE_bucket_gens))					\
1368 	x(snapshot_trees,	15,	0,					\
1369 	  BIT_ULL(KEY_TYPE_snapshot_tree))					\
1370 	x(deleted_inodes,	16,	BTREE_ID_SNAPSHOT_FIELD,		\
1371 	  BIT_ULL(KEY_TYPE_set))						\
1372 	x(logged_ops,		17,	0,					\
1373 	  BIT_ULL(KEY_TYPE_logged_op_truncate)|					\
1374 	  BIT_ULL(KEY_TYPE_logged_op_finsert))					\
1375 	x(rebalance_work,	18,	BTREE_ID_SNAPSHOT_FIELD,		\
1376 	  BIT_ULL(KEY_TYPE_set)|BIT_ULL(KEY_TYPE_cookie))			\
1377 	x(subvolume_children,	19,	0,					\
1378 	  BIT_ULL(KEY_TYPE_set))
1379 
1380 enum btree_id {
1381 #define x(name, nr, ...) BTREE_ID_##name = nr,
1382 	BCH_BTREE_IDS()
1383 #undef x
1384 	BTREE_ID_NR
1385 };
1386 
1387 /*
1388  * Maximum number of btrees that we will _ever_ have under the current scheme,
1389  * where we refer to them with 64 bit bitfields - and we also need a bit for
1390  * the interior btree node type:
1391  */
1392 #define BTREE_ID_NR_MAX		63
1393 
1394 static inline bool btree_id_is_alloc(enum btree_id id)
1395 {
1396 	switch (id) {
1397 	case BTREE_ID_alloc:
1398 	case BTREE_ID_backpointers:
1399 	case BTREE_ID_need_discard:
1400 	case BTREE_ID_freespace:
1401 	case BTREE_ID_bucket_gens:
1402 		return true;
1403 	default:
1404 		return false;
1405 	}
1406 }
1407 
1408 #define BTREE_MAX_DEPTH		4U
1409 
1410 /* Btree nodes */
1411 
1412 /*
1413  * Btree nodes
1414  *
1415  * On disk a btree node is a list/log of these; within each set the keys are
1416  * sorted
1417  */
1418 struct bset {
1419 	__le64			seq;
1420 
1421 	/*
1422 	 * Highest journal entry this bset contains keys for.
1423 	 * If on recovery we don't see that journal entry, this bset is ignored:
1424 	 * this allows us to preserve the order of all index updates after a
1425 	 * crash, since the journal records a total order of all index updates
1426 	 * and anything that didn't make it to the journal doesn't get used.
1427 	 */
1428 	__le64			journal_seq;
1429 
1430 	__le32			flags;
1431 	__le16			version;
1432 	__le16			u64s; /* count of d[] in u64s */
1433 
1434 	struct bkey_packed	start[0];
1435 	__u64			_data[];
1436 } __packed __aligned(8);
1437 
1438 LE32_BITMASK(BSET_CSUM_TYPE,	struct bset, flags, 0, 4);
1439 
1440 LE32_BITMASK(BSET_BIG_ENDIAN,	struct bset, flags, 4, 5);
1441 LE32_BITMASK(BSET_SEPARATE_WHITEOUTS,
1442 				struct bset, flags, 5, 6);
1443 
1444 /* Sector offset within the btree node: */
1445 LE32_BITMASK(BSET_OFFSET,	struct bset, flags, 16, 32);
1446 
1447 struct btree_node {
1448 	struct bch_csum		csum;
1449 	__le64			magic;
1450 
1451 	/* this flags field is encrypted, unlike bset->flags: */
1452 	__le64			flags;
1453 
1454 	/* Closed interval: */
1455 	struct bpos		min_key;
1456 	struct bpos		max_key;
1457 	struct bch_extent_ptr	_ptr; /* not used anymore */
1458 	struct bkey_format	format;
1459 
1460 	union {
1461 	struct bset		keys;
1462 	struct {
1463 		__u8		pad[22];
1464 		__le16		u64s;
1465 		__u64		_data[0];
1466 
1467 	};
1468 	};
1469 } __packed __aligned(8);
1470 
1471 LE64_BITMASK(BTREE_NODE_ID_LO,	struct btree_node, flags,  0,  4);
1472 LE64_BITMASK(BTREE_NODE_LEVEL,	struct btree_node, flags,  4,  8);
1473 LE64_BITMASK(BTREE_NODE_NEW_EXTENT_OVERWRITE,
1474 				struct btree_node, flags,  8,  9);
1475 LE64_BITMASK(BTREE_NODE_ID_HI,	struct btree_node, flags,  9, 25);
1476 /* 25-32 unused */
1477 LE64_BITMASK(BTREE_NODE_SEQ,	struct btree_node, flags, 32, 64);
1478 
1479 static inline __u64 BTREE_NODE_ID(struct btree_node *n)
1480 {
1481 	return BTREE_NODE_ID_LO(n) | (BTREE_NODE_ID_HI(n) << 4);
1482 }
1483 
1484 static inline void SET_BTREE_NODE_ID(struct btree_node *n, __u64 v)
1485 {
1486 	SET_BTREE_NODE_ID_LO(n, v);
1487 	SET_BTREE_NODE_ID_HI(n, v >> 4);
1488 }
1489 
1490 struct btree_node_entry {
1491 	struct bch_csum		csum;
1492 
1493 	union {
1494 	struct bset		keys;
1495 	struct {
1496 		__u8		pad[22];
1497 		__le16		u64s;
1498 		__u64		_data[0];
1499 	};
1500 	};
1501 } __packed __aligned(8);
1502 
1503 #endif /* _BCACHEFS_FORMAT_H */
1504