xref: /linux/fs/bcachefs/bcachefs_format.h (revision e3234e547a4db0572e271e490d044bdb4cb7233b)
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 "vstructs.h"
80 
81 #ifdef __KERNEL__
82 typedef uuid_t __uuid_t;
83 #endif
84 
85 #define BITMASK(name, type, field, offset, end)				\
86 static const __maybe_unused unsigned	name##_OFFSET = offset;		\
87 static const __maybe_unused unsigned	name##_BITS = (end - offset);	\
88 									\
89 static inline __u64 name(const type *k)					\
90 {									\
91 	return (k->field >> offset) & ~(~0ULL << (end - offset));	\
92 }									\
93 									\
94 static inline void SET_##name(type *k, __u64 v)				\
95 {									\
96 	k->field &= ~(~(~0ULL << (end - offset)) << offset);		\
97 	k->field |= (v & ~(~0ULL << (end - offset))) << offset;		\
98 }
99 
100 #define LE_BITMASK(_bits, name, type, field, offset, end)		\
101 static const __maybe_unused unsigned	name##_OFFSET = offset;		\
102 static const __maybe_unused unsigned	name##_BITS = (end - offset);	\
103 static const __maybe_unused __u##_bits	name##_MAX = (1ULL << (end - offset)) - 1;\
104 									\
105 static inline __u64 name(const type *k)					\
106 {									\
107 	return (__le##_bits##_to_cpu(k->field) >> offset) &		\
108 		~(~0ULL << (end - offset));				\
109 }									\
110 									\
111 static inline void SET_##name(type *k, __u64 v)				\
112 {									\
113 	__u##_bits new = __le##_bits##_to_cpu(k->field);		\
114 									\
115 	new &= ~(~(~0ULL << (end - offset)) << offset);			\
116 	new |= (v & ~(~0ULL << (end - offset))) << offset;		\
117 	k->field = __cpu_to_le##_bits(new);				\
118 }
119 
120 #define LE16_BITMASK(n, t, f, o, e)	LE_BITMASK(16, n, t, f, o, e)
121 #define LE32_BITMASK(n, t, f, o, e)	LE_BITMASK(32, n, t, f, o, e)
122 #define LE64_BITMASK(n, t, f, o, e)	LE_BITMASK(64, n, t, f, o, e)
123 
124 struct bkey_format {
125 	__u8		key_u64s;
126 	__u8		nr_fields;
127 	/* One unused slot for now: */
128 	__u8		bits_per_field[6];
129 	__le64		field_offset[6];
130 };
131 
132 /* Btree keys - all units are in sectors */
133 
134 struct bpos {
135 	/*
136 	 * Word order matches machine byte order - btree code treats a bpos as a
137 	 * single large integer, for search/comparison purposes
138 	 *
139 	 * Note that wherever a bpos is embedded in another on disk data
140 	 * structure, it has to be byte swabbed when reading in metadata that
141 	 * wasn't written in native endian order:
142 	 */
143 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
144 	__u32		snapshot;
145 	__u64		offset;
146 	__u64		inode;
147 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
148 	__u64		inode;
149 	__u64		offset;		/* Points to end of extent - sectors */
150 	__u32		snapshot;
151 #else
152 #error edit for your odd byteorder.
153 #endif
154 } __packed __aligned(4);
155 
156 #define KEY_INODE_MAX			((__u64)~0ULL)
157 #define KEY_OFFSET_MAX			((__u64)~0ULL)
158 #define KEY_SNAPSHOT_MAX		((__u32)~0U)
159 #define KEY_SIZE_MAX			((__u32)~0U)
160 
161 static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
162 {
163 	return (struct bpos) {
164 		.inode		= inode,
165 		.offset		= offset,
166 		.snapshot	= snapshot,
167 	};
168 }
169 
170 #define POS_MIN				SPOS(0, 0, 0)
171 #define POS_MAX				SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
172 #define SPOS_MAX			SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
173 #define POS(_inode, _offset)		SPOS(_inode, _offset, 0)
174 
175 /* Empty placeholder struct, for container_of() */
176 struct bch_val {
177 	__u64		__nothing[0];
178 };
179 
180 struct bversion {
181 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
182 	__u64		lo;
183 	__u32		hi;
184 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
185 	__u32		hi;
186 	__u64		lo;
187 #endif
188 } __packed __aligned(4);
189 
190 struct bkey {
191 	/* Size of combined key and value, in u64s */
192 	__u8		u64s;
193 
194 	/* Format of key (0 for format local to btree node) */
195 #if defined(__LITTLE_ENDIAN_BITFIELD)
196 	__u8		format:7,
197 			needs_whiteout:1;
198 #elif defined (__BIG_ENDIAN_BITFIELD)
199 	__u8		needs_whiteout:1,
200 			format:7;
201 #else
202 #error edit for your odd byteorder.
203 #endif
204 
205 	/* Type of the value */
206 	__u8		type;
207 
208 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
209 	__u8		pad[1];
210 
211 	struct bversion	version;
212 	__u32		size;		/* extent size, in sectors */
213 	struct bpos	p;
214 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
215 	struct bpos	p;
216 	__u32		size;		/* extent size, in sectors */
217 	struct bversion	version;
218 
219 	__u8		pad[1];
220 #endif
221 } __packed __aligned(8);
222 
223 struct bkey_packed {
224 	__u64		_data[0];
225 
226 	/* Size of combined key and value, in u64s */
227 	__u8		u64s;
228 
229 	/* Format of key (0 for format local to btree node) */
230 
231 	/*
232 	 * XXX: next incompat on disk format change, switch format and
233 	 * needs_whiteout - bkey_packed() will be cheaper if format is the high
234 	 * bits of the bitfield
235 	 */
236 #if defined(__LITTLE_ENDIAN_BITFIELD)
237 	__u8		format:7,
238 			needs_whiteout:1;
239 #elif defined (__BIG_ENDIAN_BITFIELD)
240 	__u8		needs_whiteout:1,
241 			format:7;
242 #endif
243 
244 	/* Type of the value */
245 	__u8		type;
246 	__u8		key_start[0];
247 
248 	/*
249 	 * We copy bkeys with struct assignment in various places, and while
250 	 * that shouldn't be done with packed bkeys we can't disallow it in C,
251 	 * and it's legal to cast a bkey to a bkey_packed  - so padding it out
252 	 * to the same size as struct bkey should hopefully be safest.
253 	 */
254 	__u8		pad[sizeof(struct bkey) - 3];
255 } __packed __aligned(8);
256 
257 typedef struct {
258 	__le64			lo;
259 	__le64			hi;
260 } bch_le128;
261 
262 #define BKEY_U64s			(sizeof(struct bkey) / sizeof(__u64))
263 #define BKEY_U64s_MAX			U8_MAX
264 #define BKEY_VAL_U64s_MAX		(BKEY_U64s_MAX - BKEY_U64s)
265 
266 #define KEY_PACKED_BITS_START		24
267 
268 #define KEY_FORMAT_LOCAL_BTREE		0
269 #define KEY_FORMAT_CURRENT		1
270 
271 enum bch_bkey_fields {
272 	BKEY_FIELD_INODE,
273 	BKEY_FIELD_OFFSET,
274 	BKEY_FIELD_SNAPSHOT,
275 	BKEY_FIELD_SIZE,
276 	BKEY_FIELD_VERSION_HI,
277 	BKEY_FIELD_VERSION_LO,
278 	BKEY_NR_FIELDS,
279 };
280 
281 #define bkey_format_field(name, field)					\
282 	[BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8)
283 
284 #define BKEY_FORMAT_CURRENT						\
285 ((struct bkey_format) {							\
286 	.key_u64s	= BKEY_U64s,					\
287 	.nr_fields	= BKEY_NR_FIELDS,				\
288 	.bits_per_field = {						\
289 		bkey_format_field(INODE,	p.inode),		\
290 		bkey_format_field(OFFSET,	p.offset),		\
291 		bkey_format_field(SNAPSHOT,	p.snapshot),		\
292 		bkey_format_field(SIZE,		size),			\
293 		bkey_format_field(VERSION_HI,	version.hi),		\
294 		bkey_format_field(VERSION_LO,	version.lo),		\
295 	},								\
296 })
297 
298 /* bkey with inline value */
299 struct bkey_i {
300 	__u64			_data[0];
301 
302 	struct bkey	k;
303 	struct bch_val	v;
304 };
305 
306 #define KEY(_inode, _offset, _size)					\
307 ((struct bkey) {							\
308 	.u64s		= BKEY_U64s,					\
309 	.format		= KEY_FORMAT_CURRENT,				\
310 	.p		= POS(_inode, _offset),				\
311 	.size		= _size,					\
312 })
313 
314 static inline void bkey_init(struct bkey *k)
315 {
316 	*k = KEY(0, 0, 0);
317 }
318 
319 #define bkey_bytes(_k)		((_k)->u64s * sizeof(__u64))
320 
321 #define __BKEY_PADDED(key, pad)					\
322 	struct bkey_i key; __u64 key ## _pad[pad]
323 
324 /*
325  * - DELETED keys are used internally to mark keys that should be ignored but
326  *   override keys in composition order.  Their version number is ignored.
327  *
328  * - DISCARDED keys indicate that the data is all 0s because it has been
329  *   discarded. DISCARDs may have a version; if the version is nonzero the key
330  *   will be persistent, otherwise the key will be dropped whenever the btree
331  *   node is rewritten (like DELETED keys).
332  *
333  * - ERROR: any read of the data returns a read error, as the data was lost due
334  *   to a failing device. Like DISCARDED keys, they can be removed (overridden)
335  *   by new writes or cluster-wide GC. Node repair can also overwrite them with
336  *   the same or a more recent version number, but not with an older version
337  *   number.
338  *
339  * - WHITEOUT: for hash table btrees
340  */
341 #define BCH_BKEY_TYPES()				\
342 	x(deleted,		0)			\
343 	x(whiteout,		1)			\
344 	x(error,		2)			\
345 	x(cookie,		3)			\
346 	x(hash_whiteout,	4)			\
347 	x(btree_ptr,		5)			\
348 	x(extent,		6)			\
349 	x(reservation,		7)			\
350 	x(inode,		8)			\
351 	x(inode_generation,	9)			\
352 	x(dirent,		10)			\
353 	x(xattr,		11)			\
354 	x(alloc,		12)			\
355 	x(quota,		13)			\
356 	x(stripe,		14)			\
357 	x(reflink_p,		15)			\
358 	x(reflink_v,		16)			\
359 	x(inline_data,		17)			\
360 	x(btree_ptr_v2,		18)			\
361 	x(indirect_inline_data,	19)			\
362 	x(alloc_v2,		20)			\
363 	x(subvolume,		21)			\
364 	x(snapshot,		22)			\
365 	x(inode_v2,		23)			\
366 	x(alloc_v3,		24)			\
367 	x(set,			25)			\
368 	x(lru,			26)			\
369 	x(alloc_v4,		27)			\
370 	x(backpointer,		28)			\
371 	x(inode_v3,		29)			\
372 	x(bucket_gens,		30)			\
373 	x(snapshot_tree,	31)			\
374 	x(logged_op_truncate,	32)			\
375 	x(logged_op_finsert,	33)
376 
377 enum bch_bkey_type {
378 #define x(name, nr) KEY_TYPE_##name	= nr,
379 	BCH_BKEY_TYPES()
380 #undef x
381 	KEY_TYPE_MAX,
382 };
383 
384 struct bch_deleted {
385 	struct bch_val		v;
386 };
387 
388 struct bch_whiteout {
389 	struct bch_val		v;
390 };
391 
392 struct bch_error {
393 	struct bch_val		v;
394 };
395 
396 struct bch_cookie {
397 	struct bch_val		v;
398 	__le64			cookie;
399 };
400 
401 struct bch_hash_whiteout {
402 	struct bch_val		v;
403 };
404 
405 struct bch_set {
406 	struct bch_val		v;
407 };
408 
409 /* Extents */
410 
411 /*
412  * In extent bkeys, the value is a list of pointers (bch_extent_ptr), optionally
413  * preceded by checksum/compression information (bch_extent_crc32 or
414  * bch_extent_crc64).
415  *
416  * One major determining factor in the format of extents is how we handle and
417  * represent extents that have been partially overwritten and thus trimmed:
418  *
419  * If an extent is not checksummed or compressed, when the extent is trimmed we
420  * don't have to remember the extent we originally allocated and wrote: we can
421  * merely adjust ptr->offset to point to the start of the data that is currently
422  * live. The size field in struct bkey records the current (live) size of the
423  * extent, and is also used to mean "size of region on disk that we point to" in
424  * this case.
425  *
426  * Thus an extent that is not checksummed or compressed will consist only of a
427  * list of bch_extent_ptrs, with none of the fields in
428  * bch_extent_crc32/bch_extent_crc64.
429  *
430  * When an extent is checksummed or compressed, it's not possible to read only
431  * the data that is currently live: we have to read the entire extent that was
432  * originally written, and then return only the part of the extent that is
433  * currently live.
434  *
435  * Thus, in addition to the current size of the extent in struct bkey, we need
436  * to store the size of the originally allocated space - this is the
437  * compressed_size and uncompressed_size fields in bch_extent_crc32/64. Also,
438  * when the extent is trimmed, instead of modifying the offset field of the
439  * pointer, we keep a second smaller offset field - "offset into the original
440  * extent of the currently live region".
441  *
442  * The other major determining factor is replication and data migration:
443  *
444  * Each pointer may have its own bch_extent_crc32/64. When doing a replicated
445  * write, we will initially write all the replicas in the same format, with the
446  * same checksum type and compression format - however, when copygc runs later (or
447  * tiering/cache promotion, anything that moves data), it is not in general
448  * going to rewrite all the pointers at once - one of the replicas may be in a
449  * bucket on one device that has very little fragmentation while another lives
450  * in a bucket that has become heavily fragmented, and thus is being rewritten
451  * sooner than the rest.
452  *
453  * Thus it will only move a subset of the pointers (or in the case of
454  * tiering/cache promotion perhaps add a single pointer without dropping any
455  * current pointers), and if the extent has been partially overwritten it must
456  * write only the currently live portion (or copygc would not be able to reduce
457  * fragmentation!) - which necessitates a different bch_extent_crc format for
458  * the new pointer.
459  *
460  * But in the interests of space efficiency, we don't want to store one
461  * bch_extent_crc for each pointer if we don't have to.
462  *
463  * Thus, a bch_extent consists of bch_extent_crc32s, bch_extent_crc64s, and
464  * bch_extent_ptrs appended arbitrarily one after the other. We determine the
465  * type of a given entry with a scheme similar to utf8 (except we're encoding a
466  * type, not a size), encoding the type in the position of the first set bit:
467  *
468  * bch_extent_crc32	- 0b1
469  * bch_extent_ptr	- 0b10
470  * bch_extent_crc64	- 0b100
471  *
472  * We do it this way because bch_extent_crc32 is _very_ constrained on bits (and
473  * bch_extent_crc64 is the least constrained).
474  *
475  * Then, each bch_extent_crc32/64 applies to the pointers that follow after it,
476  * until the next bch_extent_crc32/64.
477  *
478  * If there are no bch_extent_crcs preceding a bch_extent_ptr, then that pointer
479  * is neither checksummed nor compressed.
480  */
481 
482 /* 128 bits, sufficient for cryptographic MACs: */
483 struct bch_csum {
484 	__le64			lo;
485 	__le64			hi;
486 } __packed __aligned(8);
487 
488 #define BCH_EXTENT_ENTRY_TYPES()		\
489 	x(ptr,			0)		\
490 	x(crc32,		1)		\
491 	x(crc64,		2)		\
492 	x(crc128,		3)		\
493 	x(stripe_ptr,		4)		\
494 	x(rebalance,		5)
495 #define BCH_EXTENT_ENTRY_MAX	6
496 
497 enum bch_extent_entry_type {
498 #define x(f, n) BCH_EXTENT_ENTRY_##f = n,
499 	BCH_EXTENT_ENTRY_TYPES()
500 #undef x
501 };
502 
503 /* Compressed/uncompressed size are stored biased by 1: */
504 struct bch_extent_crc32 {
505 #if defined(__LITTLE_ENDIAN_BITFIELD)
506 	__u32			type:2,
507 				_compressed_size:7,
508 				_uncompressed_size:7,
509 				offset:7,
510 				_unused:1,
511 				csum_type:4,
512 				compression_type:4;
513 	__u32			csum;
514 #elif defined (__BIG_ENDIAN_BITFIELD)
515 	__u32			csum;
516 	__u32			compression_type:4,
517 				csum_type:4,
518 				_unused:1,
519 				offset:7,
520 				_uncompressed_size:7,
521 				_compressed_size:7,
522 				type:2;
523 #endif
524 } __packed __aligned(8);
525 
526 #define CRC32_SIZE_MAX		(1U << 7)
527 #define CRC32_NONCE_MAX		0
528 
529 struct bch_extent_crc64 {
530 #if defined(__LITTLE_ENDIAN_BITFIELD)
531 	__u64			type:3,
532 				_compressed_size:9,
533 				_uncompressed_size:9,
534 				offset:9,
535 				nonce:10,
536 				csum_type:4,
537 				compression_type:4,
538 				csum_hi:16;
539 #elif defined (__BIG_ENDIAN_BITFIELD)
540 	__u64			csum_hi:16,
541 				compression_type:4,
542 				csum_type:4,
543 				nonce:10,
544 				offset:9,
545 				_uncompressed_size:9,
546 				_compressed_size:9,
547 				type:3;
548 #endif
549 	__u64			csum_lo;
550 } __packed __aligned(8);
551 
552 #define CRC64_SIZE_MAX		(1U << 9)
553 #define CRC64_NONCE_MAX		((1U << 10) - 1)
554 
555 struct bch_extent_crc128 {
556 #if defined(__LITTLE_ENDIAN_BITFIELD)
557 	__u64			type:4,
558 				_compressed_size:13,
559 				_uncompressed_size:13,
560 				offset:13,
561 				nonce:13,
562 				csum_type:4,
563 				compression_type:4;
564 #elif defined (__BIG_ENDIAN_BITFIELD)
565 	__u64			compression_type:4,
566 				csum_type:4,
567 				nonce:13,
568 				offset:13,
569 				_uncompressed_size:13,
570 				_compressed_size:13,
571 				type:4;
572 #endif
573 	struct bch_csum		csum;
574 } __packed __aligned(8);
575 
576 #define CRC128_SIZE_MAX		(1U << 13)
577 #define CRC128_NONCE_MAX	((1U << 13) - 1)
578 
579 /*
580  * @reservation - pointer hasn't been written to, just reserved
581  */
582 struct bch_extent_ptr {
583 #if defined(__LITTLE_ENDIAN_BITFIELD)
584 	__u64			type:1,
585 				cached:1,
586 				unused:1,
587 				unwritten:1,
588 				offset:44, /* 8 petabytes */
589 				dev:8,
590 				gen:8;
591 #elif defined (__BIG_ENDIAN_BITFIELD)
592 	__u64			gen:8,
593 				dev:8,
594 				offset:44,
595 				unwritten:1,
596 				unused:1,
597 				cached:1,
598 				type:1;
599 #endif
600 } __packed __aligned(8);
601 
602 struct bch_extent_stripe_ptr {
603 #if defined(__LITTLE_ENDIAN_BITFIELD)
604 	__u64			type:5,
605 				block:8,
606 				redundancy:4,
607 				idx:47;
608 #elif defined (__BIG_ENDIAN_BITFIELD)
609 	__u64			idx:47,
610 				redundancy:4,
611 				block:8,
612 				type:5;
613 #endif
614 };
615 
616 struct bch_extent_rebalance {
617 #if defined(__LITTLE_ENDIAN_BITFIELD)
618 	__u64			type:6,
619 				unused:34,
620 				compression:8, /* enum bch_compression_opt */
621 				target:16;
622 #elif defined (__BIG_ENDIAN_BITFIELD)
623 	__u64			target:16,
624 				compression:8,
625 				unused:34,
626 				type:6;
627 #endif
628 };
629 
630 union bch_extent_entry {
631 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ ||  __BITS_PER_LONG == 64
632 	unsigned long			type;
633 #elif __BITS_PER_LONG == 32
634 	struct {
635 		unsigned long		pad;
636 		unsigned long		type;
637 	};
638 #else
639 #error edit for your odd byteorder.
640 #endif
641 
642 #define x(f, n) struct bch_extent_##f	f;
643 	BCH_EXTENT_ENTRY_TYPES()
644 #undef x
645 };
646 
647 struct bch_btree_ptr {
648 	struct bch_val		v;
649 
650 	__u64			_data[0];
651 	struct bch_extent_ptr	start[];
652 } __packed __aligned(8);
653 
654 struct bch_btree_ptr_v2 {
655 	struct bch_val		v;
656 
657 	__u64			mem_ptr;
658 	__le64			seq;
659 	__le16			sectors_written;
660 	__le16			flags;
661 	struct bpos		min_key;
662 	__u64			_data[0];
663 	struct bch_extent_ptr	start[];
664 } __packed __aligned(8);
665 
666 LE16_BITMASK(BTREE_PTR_RANGE_UPDATED,	struct bch_btree_ptr_v2, flags, 0, 1);
667 
668 struct bch_extent {
669 	struct bch_val		v;
670 
671 	__u64			_data[0];
672 	union bch_extent_entry	start[];
673 } __packed __aligned(8);
674 
675 struct bch_reservation {
676 	struct bch_val		v;
677 
678 	__le32			generation;
679 	__u8			nr_replicas;
680 	__u8			pad[3];
681 } __packed __aligned(8);
682 
683 /* Maximum size (in u64s) a single pointer could be: */
684 #define BKEY_EXTENT_PTR_U64s_MAX\
685 	((sizeof(struct bch_extent_crc128) +			\
686 	  sizeof(struct bch_extent_ptr)) / sizeof(__u64))
687 
688 /* Maximum possible size of an entire extent value: */
689 #define BKEY_EXTENT_VAL_U64s_MAX				\
690 	(1 + BKEY_EXTENT_PTR_U64s_MAX * (BCH_REPLICAS_MAX + 1))
691 
692 /* * Maximum possible size of an entire extent, key + value: */
693 #define BKEY_EXTENT_U64s_MAX		(BKEY_U64s + BKEY_EXTENT_VAL_U64s_MAX)
694 
695 /* Btree pointers don't carry around checksums: */
696 #define BKEY_BTREE_PTR_VAL_U64s_MAX				\
697 	((sizeof(struct bch_btree_ptr_v2) +			\
698 	  sizeof(struct bch_extent_ptr) * BCH_REPLICAS_MAX) / sizeof(__u64))
699 #define BKEY_BTREE_PTR_U64s_MAX					\
700 	(BKEY_U64s + BKEY_BTREE_PTR_VAL_U64s_MAX)
701 
702 /* Inodes */
703 
704 #define BLOCKDEV_INODE_MAX	4096
705 
706 #define BCACHEFS_ROOT_INO	4096
707 
708 struct bch_inode {
709 	struct bch_val		v;
710 
711 	__le64			bi_hash_seed;
712 	__le32			bi_flags;
713 	__le16			bi_mode;
714 	__u8			fields[];
715 } __packed __aligned(8);
716 
717 struct bch_inode_v2 {
718 	struct bch_val		v;
719 
720 	__le64			bi_journal_seq;
721 	__le64			bi_hash_seed;
722 	__le64			bi_flags;
723 	__le16			bi_mode;
724 	__u8			fields[];
725 } __packed __aligned(8);
726 
727 struct bch_inode_v3 {
728 	struct bch_val		v;
729 
730 	__le64			bi_journal_seq;
731 	__le64			bi_hash_seed;
732 	__le64			bi_flags;
733 	__le64			bi_sectors;
734 	__le64			bi_size;
735 	__le64			bi_version;
736 	__u8			fields[];
737 } __packed __aligned(8);
738 
739 #define INODEv3_FIELDS_START_INITIAL	6
740 #define INODEv3_FIELDS_START_CUR	(offsetof(struct bch_inode_v3, fields) / sizeof(__u64))
741 
742 struct bch_inode_generation {
743 	struct bch_val		v;
744 
745 	__le32			bi_generation;
746 	__le32			pad;
747 } __packed __aligned(8);
748 
749 /*
750  * bi_subvol and bi_parent_subvol are only set for subvolume roots:
751  */
752 
753 #define BCH_INODE_FIELDS_v2()			\
754 	x(bi_atime,			96)	\
755 	x(bi_ctime,			96)	\
756 	x(bi_mtime,			96)	\
757 	x(bi_otime,			96)	\
758 	x(bi_size,			64)	\
759 	x(bi_sectors,			64)	\
760 	x(bi_uid,			32)	\
761 	x(bi_gid,			32)	\
762 	x(bi_nlink,			32)	\
763 	x(bi_generation,		32)	\
764 	x(bi_dev,			32)	\
765 	x(bi_data_checksum,		8)	\
766 	x(bi_compression,		8)	\
767 	x(bi_project,			32)	\
768 	x(bi_background_compression,	8)	\
769 	x(bi_data_replicas,		8)	\
770 	x(bi_promote_target,		16)	\
771 	x(bi_foreground_target,		16)	\
772 	x(bi_background_target,		16)	\
773 	x(bi_erasure_code,		16)	\
774 	x(bi_fields_set,		16)	\
775 	x(bi_dir,			64)	\
776 	x(bi_dir_offset,		64)	\
777 	x(bi_subvol,			32)	\
778 	x(bi_parent_subvol,		32)
779 
780 #define BCH_INODE_FIELDS_v3()			\
781 	x(bi_atime,			96)	\
782 	x(bi_ctime,			96)	\
783 	x(bi_mtime,			96)	\
784 	x(bi_otime,			96)	\
785 	x(bi_uid,			32)	\
786 	x(bi_gid,			32)	\
787 	x(bi_nlink,			32)	\
788 	x(bi_generation,		32)	\
789 	x(bi_dev,			32)	\
790 	x(bi_data_checksum,		8)	\
791 	x(bi_compression,		8)	\
792 	x(bi_project,			32)	\
793 	x(bi_background_compression,	8)	\
794 	x(bi_data_replicas,		8)	\
795 	x(bi_promote_target,		16)	\
796 	x(bi_foreground_target,		16)	\
797 	x(bi_background_target,		16)	\
798 	x(bi_erasure_code,		16)	\
799 	x(bi_fields_set,		16)	\
800 	x(bi_dir,			64)	\
801 	x(bi_dir_offset,		64)	\
802 	x(bi_subvol,			32)	\
803 	x(bi_parent_subvol,		32)	\
804 	x(bi_nocow,			8)
805 
806 /* subset of BCH_INODE_FIELDS */
807 #define BCH_INODE_OPTS()			\
808 	x(data_checksum,		8)	\
809 	x(compression,			8)	\
810 	x(project,			32)	\
811 	x(background_compression,	8)	\
812 	x(data_replicas,		8)	\
813 	x(promote_target,		16)	\
814 	x(foreground_target,		16)	\
815 	x(background_target,		16)	\
816 	x(erasure_code,			16)	\
817 	x(nocow,			8)
818 
819 enum inode_opt_id {
820 #define x(name, ...)				\
821 	Inode_opt_##name,
822 	BCH_INODE_OPTS()
823 #undef  x
824 	Inode_opt_nr,
825 };
826 
827 #define BCH_INODE_FLAGS()			\
828 	x(sync,				0)	\
829 	x(immutable,			1)	\
830 	x(append,			2)	\
831 	x(nodump,			3)	\
832 	x(noatime,			4)	\
833 	x(i_size_dirty,			5)	\
834 	x(i_sectors_dirty,		6)	\
835 	x(unlinked,			7)	\
836 	x(backptr_untrusted,		8)
837 
838 /* bits 20+ reserved for packed fields below: */
839 
840 enum bch_inode_flags {
841 #define x(t, n)	BCH_INODE_##t = 1U << n,
842 	BCH_INODE_FLAGS()
843 #undef x
844 };
845 
846 enum __bch_inode_flags {
847 #define x(t, n)	__BCH_INODE_##t = n,
848 	BCH_INODE_FLAGS()
849 #undef x
850 };
851 
852 LE32_BITMASK(INODE_STR_HASH,	struct bch_inode, bi_flags, 20, 24);
853 LE32_BITMASK(INODE_NR_FIELDS,	struct bch_inode, bi_flags, 24, 31);
854 LE32_BITMASK(INODE_NEW_VARINT,	struct bch_inode, bi_flags, 31, 32);
855 
856 LE64_BITMASK(INODEv2_STR_HASH,	struct bch_inode_v2, bi_flags, 20, 24);
857 LE64_BITMASK(INODEv2_NR_FIELDS,	struct bch_inode_v2, bi_flags, 24, 31);
858 
859 LE64_BITMASK(INODEv3_STR_HASH,	struct bch_inode_v3, bi_flags, 20, 24);
860 LE64_BITMASK(INODEv3_NR_FIELDS,	struct bch_inode_v3, bi_flags, 24, 31);
861 
862 LE64_BITMASK(INODEv3_FIELDS_START,
863 				struct bch_inode_v3, bi_flags, 31, 36);
864 LE64_BITMASK(INODEv3_MODE,	struct bch_inode_v3, bi_flags, 36, 52);
865 
866 /* Dirents */
867 
868 /*
869  * Dirents (and xattrs) have to implement string lookups; since our b-tree
870  * doesn't support arbitrary length strings for the key, we instead index by a
871  * 64 bit hash (currently truncated sha1) of the string, stored in the offset
872  * field of the key - using linear probing to resolve hash collisions. This also
873  * provides us with the readdir cookie posix requires.
874  *
875  * Linear probing requires us to use whiteouts for deletions, in the event of a
876  * collision:
877  */
878 
879 struct bch_dirent {
880 	struct bch_val		v;
881 
882 	/* Target inode number: */
883 	union {
884 	__le64			d_inum;
885 	struct {		/* DT_SUBVOL */
886 	__le32			d_child_subvol;
887 	__le32			d_parent_subvol;
888 	};
889 	};
890 
891 	/*
892 	 * Copy of mode bits 12-15 from the target inode - so userspace can get
893 	 * the filetype without having to do a stat()
894 	 */
895 	__u8			d_type;
896 
897 	__u8			d_name[];
898 } __packed __aligned(8);
899 
900 #define DT_SUBVOL	16
901 #define BCH_DT_MAX	17
902 
903 #define BCH_NAME_MAX	512
904 
905 /* Xattrs */
906 
907 #define KEY_TYPE_XATTR_INDEX_USER			0
908 #define KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS	1
909 #define KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT	2
910 #define KEY_TYPE_XATTR_INDEX_TRUSTED			3
911 #define KEY_TYPE_XATTR_INDEX_SECURITY	        4
912 
913 struct bch_xattr {
914 	struct bch_val		v;
915 	__u8			x_type;
916 	__u8			x_name_len;
917 	__le16			x_val_len;
918 	__u8			x_name[];
919 } __packed __aligned(8);
920 
921 /* Bucket/allocation information: */
922 
923 struct bch_alloc {
924 	struct bch_val		v;
925 	__u8			fields;
926 	__u8			gen;
927 	__u8			data[];
928 } __packed __aligned(8);
929 
930 #define BCH_ALLOC_FIELDS_V1()			\
931 	x(read_time,		16)		\
932 	x(write_time,		16)		\
933 	x(data_type,		8)		\
934 	x(dirty_sectors,	16)		\
935 	x(cached_sectors,	16)		\
936 	x(oldest_gen,		8)		\
937 	x(stripe,		32)		\
938 	x(stripe_redundancy,	8)
939 
940 enum {
941 #define x(name, _bits) BCH_ALLOC_FIELD_V1_##name,
942 	BCH_ALLOC_FIELDS_V1()
943 #undef x
944 };
945 
946 struct bch_alloc_v2 {
947 	struct bch_val		v;
948 	__u8			nr_fields;
949 	__u8			gen;
950 	__u8			oldest_gen;
951 	__u8			data_type;
952 	__u8			data[];
953 } __packed __aligned(8);
954 
955 #define BCH_ALLOC_FIELDS_V2()			\
956 	x(read_time,		64)		\
957 	x(write_time,		64)		\
958 	x(dirty_sectors,	32)		\
959 	x(cached_sectors,	32)		\
960 	x(stripe,		32)		\
961 	x(stripe_redundancy,	8)
962 
963 struct bch_alloc_v3 {
964 	struct bch_val		v;
965 	__le64			journal_seq;
966 	__le32			flags;
967 	__u8			nr_fields;
968 	__u8			gen;
969 	__u8			oldest_gen;
970 	__u8			data_type;
971 	__u8			data[];
972 } __packed __aligned(8);
973 
974 LE32_BITMASK(BCH_ALLOC_V3_NEED_DISCARD,struct bch_alloc_v3, flags,  0,  1)
975 LE32_BITMASK(BCH_ALLOC_V3_NEED_INC_GEN,struct bch_alloc_v3, flags,  1,  2)
976 
977 struct bch_alloc_v4 {
978 	struct bch_val		v;
979 	__u64			journal_seq;
980 	__u32			flags;
981 	__u8			gen;
982 	__u8			oldest_gen;
983 	__u8			data_type;
984 	__u8			stripe_redundancy;
985 	__u32			dirty_sectors;
986 	__u32			cached_sectors;
987 	__u64			io_time[2];
988 	__u32			stripe;
989 	__u32			nr_external_backpointers;
990 	__u64			fragmentation_lru;
991 } __packed __aligned(8);
992 
993 #define BCH_ALLOC_V4_U64s_V0	6
994 #define BCH_ALLOC_V4_U64s	(sizeof(struct bch_alloc_v4) / sizeof(__u64))
995 
996 BITMASK(BCH_ALLOC_V4_NEED_DISCARD,	struct bch_alloc_v4, flags,  0,  1)
997 BITMASK(BCH_ALLOC_V4_NEED_INC_GEN,	struct bch_alloc_v4, flags,  1,  2)
998 BITMASK(BCH_ALLOC_V4_BACKPOINTERS_START,struct bch_alloc_v4, flags,  2,  8)
999 BITMASK(BCH_ALLOC_V4_NR_BACKPOINTERS,	struct bch_alloc_v4, flags,  8,  14)
1000 
1001 #define BCH_ALLOC_V4_NR_BACKPOINTERS_MAX	40
1002 
1003 struct bch_backpointer {
1004 	struct bch_val		v;
1005 	__u8			btree_id;
1006 	__u8			level;
1007 	__u8			data_type;
1008 	__u64			bucket_offset:40;
1009 	__u32			bucket_len;
1010 	struct bpos		pos;
1011 } __packed __aligned(8);
1012 
1013 #define KEY_TYPE_BUCKET_GENS_BITS	8
1014 #define KEY_TYPE_BUCKET_GENS_NR		(1U << KEY_TYPE_BUCKET_GENS_BITS)
1015 #define KEY_TYPE_BUCKET_GENS_MASK	(KEY_TYPE_BUCKET_GENS_NR - 1)
1016 
1017 struct bch_bucket_gens {
1018 	struct bch_val		v;
1019 	u8			gens[KEY_TYPE_BUCKET_GENS_NR];
1020 } __packed __aligned(8);
1021 
1022 /* Quotas: */
1023 
1024 enum quota_types {
1025 	QTYP_USR		= 0,
1026 	QTYP_GRP		= 1,
1027 	QTYP_PRJ		= 2,
1028 	QTYP_NR			= 3,
1029 };
1030 
1031 enum quota_counters {
1032 	Q_SPC			= 0,
1033 	Q_INO			= 1,
1034 	Q_COUNTERS		= 2,
1035 };
1036 
1037 struct bch_quota_counter {
1038 	__le64			hardlimit;
1039 	__le64			softlimit;
1040 };
1041 
1042 struct bch_quota {
1043 	struct bch_val		v;
1044 	struct bch_quota_counter c[Q_COUNTERS];
1045 } __packed __aligned(8);
1046 
1047 /* Erasure coding */
1048 
1049 struct bch_stripe {
1050 	struct bch_val		v;
1051 	__le16			sectors;
1052 	__u8			algorithm;
1053 	__u8			nr_blocks;
1054 	__u8			nr_redundant;
1055 
1056 	__u8			csum_granularity_bits;
1057 	__u8			csum_type;
1058 	__u8			pad;
1059 
1060 	struct bch_extent_ptr	ptrs[];
1061 } __packed __aligned(8);
1062 
1063 /* Reflink: */
1064 
1065 struct bch_reflink_p {
1066 	struct bch_val		v;
1067 	__le64			idx;
1068 	/*
1069 	 * A reflink pointer might point to an indirect extent which is then
1070 	 * later split (by copygc or rebalance). If we only pointed to part of
1071 	 * the original indirect extent, and then one of the fragments is
1072 	 * outside the range we point to, we'd leak a refcount: so when creating
1073 	 * reflink pointers, we need to store pad values to remember the full
1074 	 * range we were taking a reference on.
1075 	 */
1076 	__le32			front_pad;
1077 	__le32			back_pad;
1078 } __packed __aligned(8);
1079 
1080 struct bch_reflink_v {
1081 	struct bch_val		v;
1082 	__le64			refcount;
1083 	union bch_extent_entry	start[0];
1084 	__u64			_data[];
1085 } __packed __aligned(8);
1086 
1087 struct bch_indirect_inline_data {
1088 	struct bch_val		v;
1089 	__le64			refcount;
1090 	u8			data[];
1091 };
1092 
1093 /* Inline data */
1094 
1095 struct bch_inline_data {
1096 	struct bch_val		v;
1097 	u8			data[];
1098 };
1099 
1100 /* Subvolumes: */
1101 
1102 #define SUBVOL_POS_MIN		POS(0, 1)
1103 #define SUBVOL_POS_MAX		POS(0, S32_MAX)
1104 #define BCACHEFS_ROOT_SUBVOL	1
1105 
1106 struct bch_subvolume {
1107 	struct bch_val		v;
1108 	__le32			flags;
1109 	__le32			snapshot;
1110 	__le64			inode;
1111 	/*
1112 	 * Snapshot subvolumes form a tree, separate from the snapshot nodes
1113 	 * tree - if this subvolume is a snapshot, this is the ID of the
1114 	 * subvolume it was created from:
1115 	 */
1116 	__le32			parent;
1117 	__le32			pad;
1118 	bch_le128		otime;
1119 };
1120 
1121 LE32_BITMASK(BCH_SUBVOLUME_RO,		struct bch_subvolume, flags,  0,  1)
1122 /*
1123  * We need to know whether a subvolume is a snapshot so we can know whether we
1124  * can delete it (or whether it should just be rm -rf'd)
1125  */
1126 LE32_BITMASK(BCH_SUBVOLUME_SNAP,	struct bch_subvolume, flags,  1,  2)
1127 LE32_BITMASK(BCH_SUBVOLUME_UNLINKED,	struct bch_subvolume, flags,  2,  3)
1128 
1129 /* Snapshots */
1130 
1131 struct bch_snapshot {
1132 	struct bch_val		v;
1133 	__le32			flags;
1134 	__le32			parent;
1135 	__le32			children[2];
1136 	__le32			subvol;
1137 	/* corresponds to a bch_snapshot_tree in BTREE_ID_snapshot_trees */
1138 	__le32			tree;
1139 	__le32			depth;
1140 	__le32			skip[3];
1141 };
1142 
1143 LE32_BITMASK(BCH_SNAPSHOT_DELETED,	struct bch_snapshot, flags,  0,  1)
1144 
1145 /* True if a subvolume points to this snapshot node: */
1146 LE32_BITMASK(BCH_SNAPSHOT_SUBVOL,	struct bch_snapshot, flags,  1,  2)
1147 
1148 /*
1149  * Snapshot trees:
1150  *
1151  * The snapshot_trees btree gives us persistent indentifier for each tree of
1152  * bch_snapshot nodes, and allow us to record and easily find the root/master
1153  * subvolume that other snapshots were created from:
1154  */
1155 struct bch_snapshot_tree {
1156 	struct bch_val		v;
1157 	__le32			master_subvol;
1158 	__le32			root_snapshot;
1159 };
1160 
1161 /* LRU btree: */
1162 
1163 struct bch_lru {
1164 	struct bch_val		v;
1165 	__le64			idx;
1166 } __packed __aligned(8);
1167 
1168 #define LRU_ID_STRIPES		(1U << 16)
1169 
1170 /* Logged operations btree: */
1171 
1172 struct bch_logged_op_truncate {
1173 	struct bch_val		v;
1174 	__le32			subvol;
1175 	__le32			pad;
1176 	__le64			inum;
1177 	__le64			new_i_size;
1178 };
1179 
1180 enum logged_op_finsert_state {
1181 	LOGGED_OP_FINSERT_start,
1182 	LOGGED_OP_FINSERT_shift_extents,
1183 	LOGGED_OP_FINSERT_finish,
1184 };
1185 
1186 struct bch_logged_op_finsert {
1187 	struct bch_val		v;
1188 	__u8			state;
1189 	__u8			pad[3];
1190 	__le32			subvol;
1191 	__le64			inum;
1192 	__le64			dst_offset;
1193 	__le64			src_offset;
1194 	__le64			pos;
1195 };
1196 
1197 /* Optional/variable size superblock sections: */
1198 
1199 struct bch_sb_field {
1200 	__u64			_data[0];
1201 	__le32			u64s;
1202 	__le32			type;
1203 };
1204 
1205 #define BCH_SB_FIELDS()				\
1206 	x(journal,	0)			\
1207 	x(members_v1,	1)			\
1208 	x(crypt,	2)			\
1209 	x(replicas_v0,	3)			\
1210 	x(quota,	4)			\
1211 	x(disk_groups,	5)			\
1212 	x(clean,	6)			\
1213 	x(replicas,	7)			\
1214 	x(journal_seq_blacklist, 8)		\
1215 	x(journal_v2,	9)			\
1216 	x(counters,	10)			\
1217 	x(members_v2,	11)			\
1218 	x(errors,	12)
1219 
1220 enum bch_sb_field_type {
1221 #define x(f, nr)	BCH_SB_FIELD_##f = nr,
1222 	BCH_SB_FIELDS()
1223 #undef x
1224 	BCH_SB_FIELD_NR
1225 };
1226 
1227 /*
1228  * Most superblock fields are replicated in all device's superblocks - a few are
1229  * not:
1230  */
1231 #define BCH_SINGLE_DEVICE_SB_FIELDS		\
1232 	((1U << BCH_SB_FIELD_journal)|		\
1233 	 (1U << BCH_SB_FIELD_journal_v2))
1234 
1235 /* BCH_SB_FIELD_journal: */
1236 
1237 struct bch_sb_field_journal {
1238 	struct bch_sb_field	field;
1239 	__le64			buckets[];
1240 };
1241 
1242 struct bch_sb_field_journal_v2 {
1243 	struct bch_sb_field	field;
1244 
1245 	struct bch_sb_field_journal_v2_entry {
1246 		__le64		start;
1247 		__le64		nr;
1248 	}			d[];
1249 };
1250 
1251 /* BCH_SB_FIELD_members_v1: */
1252 
1253 #define BCH_MIN_NR_NBUCKETS	(1 << 6)
1254 
1255 #define BCH_IOPS_MEASUREMENTS()			\
1256 	x(seqread,	0)			\
1257 	x(seqwrite,	1)			\
1258 	x(randread,	2)			\
1259 	x(randwrite,	3)
1260 
1261 enum bch_iops_measurement {
1262 #define x(t, n) BCH_IOPS_##t = n,
1263 	BCH_IOPS_MEASUREMENTS()
1264 #undef x
1265 	BCH_IOPS_NR
1266 };
1267 
1268 #define BCH_MEMBER_ERROR_TYPES()		\
1269 	x(read,		0)			\
1270 	x(write,	1)			\
1271 	x(checksum,	2)
1272 
1273 enum bch_member_error_type {
1274 #define x(t, n) BCH_MEMBER_ERROR_##t = n,
1275 	BCH_MEMBER_ERROR_TYPES()
1276 #undef x
1277 	BCH_MEMBER_ERROR_NR
1278 };
1279 
1280 struct bch_member {
1281 	__uuid_t		uuid;
1282 	__le64			nbuckets;	/* device size */
1283 	__le16			first_bucket;   /* index of first bucket used */
1284 	__le16			bucket_size;	/* sectors */
1285 	__le32			pad;
1286 	__le64			last_mount;	/* time_t */
1287 
1288 	__le64			flags;
1289 	__le32			iops[4];
1290 	__le64			errors[BCH_MEMBER_ERROR_NR];
1291 	__le64			errors_at_reset[BCH_MEMBER_ERROR_NR];
1292 	__le64			errors_reset_time;
1293 };
1294 
1295 #define BCH_MEMBER_V1_BYTES	56
1296 
1297 LE64_BITMASK(BCH_MEMBER_STATE,		struct bch_member, flags,  0,  4)
1298 /* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */
1299 LE64_BITMASK(BCH_MEMBER_DISCARD,	struct bch_member, flags, 14, 15)
1300 LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED,	struct bch_member, flags, 15, 20)
1301 LE64_BITMASK(BCH_MEMBER_GROUP,		struct bch_member, flags, 20, 28)
1302 LE64_BITMASK(BCH_MEMBER_DURABILITY,	struct bch_member, flags, 28, 30)
1303 LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
1304 					struct bch_member, flags, 30, 31)
1305 
1306 #if 0
1307 LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS,	struct bch_member, flags[1], 0,  20);
1308 LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40);
1309 #endif
1310 
1311 #define BCH_MEMBER_STATES()			\
1312 	x(rw,		0)			\
1313 	x(ro,		1)			\
1314 	x(failed,	2)			\
1315 	x(spare,	3)
1316 
1317 enum bch_member_state {
1318 #define x(t, n) BCH_MEMBER_STATE_##t = n,
1319 	BCH_MEMBER_STATES()
1320 #undef x
1321 	BCH_MEMBER_STATE_NR
1322 };
1323 
1324 struct bch_sb_field_members_v1 {
1325 	struct bch_sb_field	field;
1326 	struct bch_member	_members[]; //Members are now variable size
1327 };
1328 
1329 struct bch_sb_field_members_v2 {
1330 	struct bch_sb_field	field;
1331 	__le16			member_bytes; //size of single member entry
1332 	u8			pad[6];
1333 	struct bch_member	_members[];
1334 };
1335 
1336 /* BCH_SB_FIELD_crypt: */
1337 
1338 struct nonce {
1339 	__le32			d[4];
1340 };
1341 
1342 struct bch_key {
1343 	__le64			key[4];
1344 };
1345 
1346 #define BCH_KEY_MAGIC					\
1347 	(((__u64) 'b' <<  0)|((__u64) 'c' <<  8)|		\
1348 	 ((__u64) 'h' << 16)|((__u64) '*' << 24)|		\
1349 	 ((__u64) '*' << 32)|((__u64) 'k' << 40)|		\
1350 	 ((__u64) 'e' << 48)|((__u64) 'y' << 56))
1351 
1352 struct bch_encrypted_key {
1353 	__le64			magic;
1354 	struct bch_key		key;
1355 };
1356 
1357 /*
1358  * If this field is present in the superblock, it stores an encryption key which
1359  * is used encrypt all other data/metadata. The key will normally be encrypted
1360  * with the key userspace provides, but if encryption has been turned off we'll
1361  * just store the master key unencrypted in the superblock so we can access the
1362  * previously encrypted data.
1363  */
1364 struct bch_sb_field_crypt {
1365 	struct bch_sb_field	field;
1366 
1367 	__le64			flags;
1368 	__le64			kdf_flags;
1369 	struct bch_encrypted_key key;
1370 };
1371 
1372 LE64_BITMASK(BCH_CRYPT_KDF_TYPE,	struct bch_sb_field_crypt, flags, 0, 4);
1373 
1374 enum bch_kdf_types {
1375 	BCH_KDF_SCRYPT		= 0,
1376 	BCH_KDF_NR		= 1,
1377 };
1378 
1379 /* stored as base 2 log of scrypt params: */
1380 LE64_BITMASK(BCH_KDF_SCRYPT_N,	struct bch_sb_field_crypt, kdf_flags,  0, 16);
1381 LE64_BITMASK(BCH_KDF_SCRYPT_R,	struct bch_sb_field_crypt, kdf_flags, 16, 32);
1382 LE64_BITMASK(BCH_KDF_SCRYPT_P,	struct bch_sb_field_crypt, kdf_flags, 32, 48);
1383 
1384 /* BCH_SB_FIELD_replicas: */
1385 
1386 #define BCH_DATA_TYPES()		\
1387 	x(free,		0)		\
1388 	x(sb,		1)		\
1389 	x(journal,	2)		\
1390 	x(btree,	3)		\
1391 	x(user,		4)		\
1392 	x(cached,	5)		\
1393 	x(parity,	6)		\
1394 	x(stripe,	7)		\
1395 	x(need_gc_gens,	8)		\
1396 	x(need_discard,	9)
1397 
1398 enum bch_data_type {
1399 #define x(t, n) BCH_DATA_##t,
1400 	BCH_DATA_TYPES()
1401 #undef x
1402 	BCH_DATA_NR
1403 };
1404 
1405 static inline bool data_type_is_empty(enum bch_data_type type)
1406 {
1407 	switch (type) {
1408 	case BCH_DATA_free:
1409 	case BCH_DATA_need_gc_gens:
1410 	case BCH_DATA_need_discard:
1411 		return true;
1412 	default:
1413 		return false;
1414 	}
1415 }
1416 
1417 static inline bool data_type_is_hidden(enum bch_data_type type)
1418 {
1419 	switch (type) {
1420 	case BCH_DATA_sb:
1421 	case BCH_DATA_journal:
1422 		return true;
1423 	default:
1424 		return false;
1425 	}
1426 }
1427 
1428 struct bch_replicas_entry_v0 {
1429 	__u8			data_type;
1430 	__u8			nr_devs;
1431 	__u8			devs[];
1432 } __packed;
1433 
1434 struct bch_sb_field_replicas_v0 {
1435 	struct bch_sb_field	field;
1436 	struct bch_replicas_entry_v0 entries[];
1437 } __packed __aligned(8);
1438 
1439 struct bch_replicas_entry {
1440 	__u8			data_type;
1441 	__u8			nr_devs;
1442 	__u8			nr_required;
1443 	__u8			devs[];
1444 } __packed;
1445 
1446 #define replicas_entry_bytes(_i)					\
1447 	(offsetof(typeof(*(_i)), devs) + (_i)->nr_devs)
1448 
1449 struct bch_sb_field_replicas {
1450 	struct bch_sb_field	field;
1451 	struct bch_replicas_entry entries[];
1452 } __packed __aligned(8);
1453 
1454 /* BCH_SB_FIELD_quota: */
1455 
1456 struct bch_sb_quota_counter {
1457 	__le32				timelimit;
1458 	__le32				warnlimit;
1459 };
1460 
1461 struct bch_sb_quota_type {
1462 	__le64				flags;
1463 	struct bch_sb_quota_counter	c[Q_COUNTERS];
1464 };
1465 
1466 struct bch_sb_field_quota {
1467 	struct bch_sb_field		field;
1468 	struct bch_sb_quota_type	q[QTYP_NR];
1469 } __packed __aligned(8);
1470 
1471 /* BCH_SB_FIELD_disk_groups: */
1472 
1473 #define BCH_SB_LABEL_SIZE		32
1474 
1475 struct bch_disk_group {
1476 	__u8			label[BCH_SB_LABEL_SIZE];
1477 	__le64			flags[2];
1478 } __packed __aligned(8);
1479 
1480 LE64_BITMASK(BCH_GROUP_DELETED,		struct bch_disk_group, flags[0], 0,  1)
1481 LE64_BITMASK(BCH_GROUP_DATA_ALLOWED,	struct bch_disk_group, flags[0], 1,  6)
1482 LE64_BITMASK(BCH_GROUP_PARENT,		struct bch_disk_group, flags[0], 6, 24)
1483 
1484 struct bch_sb_field_disk_groups {
1485 	struct bch_sb_field	field;
1486 	struct bch_disk_group	entries[];
1487 } __packed __aligned(8);
1488 
1489 /* BCH_SB_FIELD_counters */
1490 
1491 #define BCH_PERSISTENT_COUNTERS()				\
1492 	x(io_read,					0)	\
1493 	x(io_write,					1)	\
1494 	x(io_move,					2)	\
1495 	x(bucket_invalidate,				3)	\
1496 	x(bucket_discard,				4)	\
1497 	x(bucket_alloc,					5)	\
1498 	x(bucket_alloc_fail,				6)	\
1499 	x(btree_cache_scan,				7)	\
1500 	x(btree_cache_reap,				8)	\
1501 	x(btree_cache_cannibalize,			9)	\
1502 	x(btree_cache_cannibalize_lock,			10)	\
1503 	x(btree_cache_cannibalize_lock_fail,		11)	\
1504 	x(btree_cache_cannibalize_unlock,		12)	\
1505 	x(btree_node_write,				13)	\
1506 	x(btree_node_read,				14)	\
1507 	x(btree_node_compact,				15)	\
1508 	x(btree_node_merge,				16)	\
1509 	x(btree_node_split,				17)	\
1510 	x(btree_node_rewrite,				18)	\
1511 	x(btree_node_alloc,				19)	\
1512 	x(btree_node_free,				20)	\
1513 	x(btree_node_set_root,				21)	\
1514 	x(btree_path_relock_fail,			22)	\
1515 	x(btree_path_upgrade_fail,			23)	\
1516 	x(btree_reserve_get_fail,			24)	\
1517 	x(journal_entry_full,				25)	\
1518 	x(journal_full,					26)	\
1519 	x(journal_reclaim_finish,			27)	\
1520 	x(journal_reclaim_start,			28)	\
1521 	x(journal_write,				29)	\
1522 	x(read_promote,					30)	\
1523 	x(read_bounce,					31)	\
1524 	x(read_split,					33)	\
1525 	x(read_retry,					32)	\
1526 	x(read_reuse_race,				34)	\
1527 	x(move_extent_read,				35)	\
1528 	x(move_extent_write,				36)	\
1529 	x(move_extent_finish,				37)	\
1530 	x(move_extent_fail,				38)	\
1531 	x(move_extent_alloc_mem_fail,			39)	\
1532 	x(copygc,					40)	\
1533 	x(copygc_wait,					41)	\
1534 	x(gc_gens_end,					42)	\
1535 	x(gc_gens_start,				43)	\
1536 	x(trans_blocked_journal_reclaim,		44)	\
1537 	x(trans_restart_btree_node_reused,		45)	\
1538 	x(trans_restart_btree_node_split,		46)	\
1539 	x(trans_restart_fault_inject,			47)	\
1540 	x(trans_restart_iter_upgrade,			48)	\
1541 	x(trans_restart_journal_preres_get,		49)	\
1542 	x(trans_restart_journal_reclaim,		50)	\
1543 	x(trans_restart_journal_res_get,		51)	\
1544 	x(trans_restart_key_cache_key_realloced,	52)	\
1545 	x(trans_restart_key_cache_raced,		53)	\
1546 	x(trans_restart_mark_replicas,			54)	\
1547 	x(trans_restart_mem_realloced,			55)	\
1548 	x(trans_restart_memory_allocation_failure,	56)	\
1549 	x(trans_restart_relock,				57)	\
1550 	x(trans_restart_relock_after_fill,		58)	\
1551 	x(trans_restart_relock_key_cache_fill,		59)	\
1552 	x(trans_restart_relock_next_node,		60)	\
1553 	x(trans_restart_relock_parent_for_fill,		61)	\
1554 	x(trans_restart_relock_path,			62)	\
1555 	x(trans_restart_relock_path_intent,		63)	\
1556 	x(trans_restart_too_many_iters,			64)	\
1557 	x(trans_restart_traverse,			65)	\
1558 	x(trans_restart_upgrade,			66)	\
1559 	x(trans_restart_would_deadlock,			67)	\
1560 	x(trans_restart_would_deadlock_write,		68)	\
1561 	x(trans_restart_injected,			69)	\
1562 	x(trans_restart_key_cache_upgrade,		70)	\
1563 	x(trans_traverse_all,				71)	\
1564 	x(transaction_commit,				72)	\
1565 	x(write_super,					73)	\
1566 	x(trans_restart_would_deadlock_recursion_limit,	74)	\
1567 	x(trans_restart_write_buffer_flush,		75)	\
1568 	x(trans_restart_split_race,			76)
1569 
1570 enum bch_persistent_counters {
1571 #define x(t, n, ...) BCH_COUNTER_##t,
1572 	BCH_PERSISTENT_COUNTERS()
1573 #undef x
1574 	BCH_COUNTER_NR
1575 };
1576 
1577 struct bch_sb_field_counters {
1578 	struct bch_sb_field	field;
1579 	__le64			d[];
1580 };
1581 
1582 /*
1583  * On clean shutdown, store btree roots and current journal sequence number in
1584  * the superblock:
1585  */
1586 struct jset_entry {
1587 	__le16			u64s;
1588 	__u8			btree_id;
1589 	__u8			level;
1590 	__u8			type; /* designates what this jset holds */
1591 	__u8			pad[3];
1592 
1593 	struct bkey_i		start[0];
1594 	__u64			_data[];
1595 };
1596 
1597 struct bch_sb_field_clean {
1598 	struct bch_sb_field	field;
1599 
1600 	__le32			flags;
1601 	__le16			_read_clock; /* no longer used */
1602 	__le16			_write_clock;
1603 	__le64			journal_seq;
1604 
1605 	struct jset_entry	start[0];
1606 	__u64			_data[];
1607 };
1608 
1609 struct journal_seq_blacklist_entry {
1610 	__le64			start;
1611 	__le64			end;
1612 };
1613 
1614 struct bch_sb_field_journal_seq_blacklist {
1615 	struct bch_sb_field	field;
1616 	struct journal_seq_blacklist_entry start[];
1617 };
1618 
1619 struct bch_sb_field_errors {
1620 	struct bch_sb_field	field;
1621 	struct bch_sb_field_error_entry {
1622 		__le64		v;
1623 		__le64		last_error_time;
1624 	}			entries[];
1625 };
1626 
1627 LE64_BITMASK(BCH_SB_ERROR_ENTRY_ID,	struct bch_sb_field_error_entry, v,  0, 16);
1628 LE64_BITMASK(BCH_SB_ERROR_ENTRY_NR,	struct bch_sb_field_error_entry, v, 16, 64);
1629 
1630 /* Superblock: */
1631 
1632 /*
1633  * New versioning scheme:
1634  * One common version number for all on disk data structures - superblock, btree
1635  * nodes, journal entries
1636  */
1637 #define BCH_VERSION_MAJOR(_v)		((__u16) ((_v) >> 10))
1638 #define BCH_VERSION_MINOR(_v)		((__u16) ((_v) & ~(~0U << 10)))
1639 #define BCH_VERSION(_major, _minor)	(((_major) << 10)|(_minor) << 0)
1640 
1641 #define RECOVERY_PASS_ALL_FSCK		(1ULL << 63)
1642 
1643 #define BCH_METADATA_VERSIONS()						\
1644 	x(bkey_renumber,		BCH_VERSION(0, 10),		\
1645 	  RECOVERY_PASS_ALL_FSCK)					\
1646 	x(inode_btree_change,		BCH_VERSION(0, 11),		\
1647 	  RECOVERY_PASS_ALL_FSCK)					\
1648 	x(snapshot,			BCH_VERSION(0, 12),		\
1649 	  RECOVERY_PASS_ALL_FSCK)					\
1650 	x(inode_backpointers,		BCH_VERSION(0, 13),		\
1651 	  RECOVERY_PASS_ALL_FSCK)					\
1652 	x(btree_ptr_sectors_written,	BCH_VERSION(0, 14),		\
1653 	  RECOVERY_PASS_ALL_FSCK)					\
1654 	x(snapshot_2,			BCH_VERSION(0, 15),		\
1655 	  BIT_ULL(BCH_RECOVERY_PASS_fs_upgrade_for_subvolumes)|		\
1656 	  BIT_ULL(BCH_RECOVERY_PASS_initialize_subvolumes)|		\
1657 	  RECOVERY_PASS_ALL_FSCK)					\
1658 	x(reflink_p_fix,		BCH_VERSION(0, 16),		\
1659 	  BIT_ULL(BCH_RECOVERY_PASS_fix_reflink_p))			\
1660 	x(subvol_dirent,		BCH_VERSION(0, 17),		\
1661 	  RECOVERY_PASS_ALL_FSCK)					\
1662 	x(inode_v2,			BCH_VERSION(0, 18),		\
1663 	  RECOVERY_PASS_ALL_FSCK)					\
1664 	x(freespace,			BCH_VERSION(0, 19),		\
1665 	  RECOVERY_PASS_ALL_FSCK)					\
1666 	x(alloc_v4,			BCH_VERSION(0, 20),		\
1667 	  RECOVERY_PASS_ALL_FSCK)					\
1668 	x(new_data_types,		BCH_VERSION(0, 21),		\
1669 	  RECOVERY_PASS_ALL_FSCK)					\
1670 	x(backpointers,			BCH_VERSION(0, 22),		\
1671 	  RECOVERY_PASS_ALL_FSCK)					\
1672 	x(inode_v3,			BCH_VERSION(0, 23),		\
1673 	  RECOVERY_PASS_ALL_FSCK)					\
1674 	x(unwritten_extents,		BCH_VERSION(0, 24),		\
1675 	  RECOVERY_PASS_ALL_FSCK)					\
1676 	x(bucket_gens,			BCH_VERSION(0, 25),		\
1677 	  BIT_ULL(BCH_RECOVERY_PASS_bucket_gens_init)|			\
1678 	  RECOVERY_PASS_ALL_FSCK)					\
1679 	x(lru_v2,			BCH_VERSION(0, 26),		\
1680 	  RECOVERY_PASS_ALL_FSCK)					\
1681 	x(fragmentation_lru,		BCH_VERSION(0, 27),		\
1682 	  RECOVERY_PASS_ALL_FSCK)					\
1683 	x(no_bps_in_alloc_keys,		BCH_VERSION(0, 28),		\
1684 	  RECOVERY_PASS_ALL_FSCK)					\
1685 	x(snapshot_trees,		BCH_VERSION(0, 29),		\
1686 	  RECOVERY_PASS_ALL_FSCK)					\
1687 	x(major_minor,			BCH_VERSION(1,  0),		\
1688 	  0)								\
1689 	x(snapshot_skiplists,		BCH_VERSION(1,  1),		\
1690 	  BIT_ULL(BCH_RECOVERY_PASS_check_snapshots))			\
1691 	x(deleted_inodes,		BCH_VERSION(1,  2),		\
1692 	  BIT_ULL(BCH_RECOVERY_PASS_check_inodes))			\
1693 	x(rebalance_work,		BCH_VERSION(1,  3),		\
1694 	  BIT_ULL(BCH_RECOVERY_PASS_set_fs_needs_rebalance))
1695 
1696 enum bcachefs_metadata_version {
1697 	bcachefs_metadata_version_min = 9,
1698 #define x(t, n, upgrade_passes)	bcachefs_metadata_version_##t = n,
1699 	BCH_METADATA_VERSIONS()
1700 #undef x
1701 	bcachefs_metadata_version_max
1702 };
1703 
1704 static const __maybe_unused
1705 unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_rebalance_work;
1706 
1707 #define bcachefs_metadata_version_current	(bcachefs_metadata_version_max - 1)
1708 
1709 #define BCH_SB_SECTOR			8
1710 #define BCH_SB_MEMBERS_MAX		64 /* XXX kill */
1711 
1712 struct bch_sb_layout {
1713 	__uuid_t		magic;	/* bcachefs superblock UUID */
1714 	__u8			layout_type;
1715 	__u8			sb_max_size_bits; /* base 2 of 512 byte sectors */
1716 	__u8			nr_superblocks;
1717 	__u8			pad[5];
1718 	__le64			sb_offset[61];
1719 } __packed __aligned(8);
1720 
1721 #define BCH_SB_LAYOUT_SECTOR	7
1722 
1723 /*
1724  * @offset	- sector where this sb was written
1725  * @version	- on disk format version
1726  * @version_min	- Oldest metadata version this filesystem contains; so we can
1727  *		  safely drop compatibility code and refuse to mount filesystems
1728  *		  we'd need it for
1729  * @magic	- identifies as a bcachefs superblock (BCHFS_MAGIC)
1730  * @seq		- incremented each time superblock is written
1731  * @uuid	- used for generating various magic numbers and identifying
1732  *                member devices, never changes
1733  * @user_uuid	- user visible UUID, may be changed
1734  * @label	- filesystem label
1735  * @seq		- identifies most recent superblock, incremented each time
1736  *		  superblock is written
1737  * @features	- enabled incompatible features
1738  */
1739 struct bch_sb {
1740 	struct bch_csum		csum;
1741 	__le16			version;
1742 	__le16			version_min;
1743 	__le16			pad[2];
1744 	__uuid_t		magic;
1745 	__uuid_t		uuid;
1746 	__uuid_t		user_uuid;
1747 	__u8			label[BCH_SB_LABEL_SIZE];
1748 	__le64			offset;
1749 	__le64			seq;
1750 
1751 	__le16			block_size;
1752 	__u8			dev_idx;
1753 	__u8			nr_devices;
1754 	__le32			u64s;
1755 
1756 	__le64			time_base_lo;
1757 	__le32			time_base_hi;
1758 	__le32			time_precision;
1759 
1760 	__le64			flags[8];
1761 	__le64			features[2];
1762 	__le64			compat[2];
1763 
1764 	struct bch_sb_layout	layout;
1765 
1766 	struct bch_sb_field	start[0];
1767 	__le64			_data[];
1768 } __packed __aligned(8);
1769 
1770 /*
1771  * Flags:
1772  * BCH_SB_INITALIZED	- set on first mount
1773  * BCH_SB_CLEAN		- did we shut down cleanly? Just a hint, doesn't affect
1774  *			  behaviour of mount/recovery path:
1775  * BCH_SB_INODE_32BIT	- limit inode numbers to 32 bits
1776  * BCH_SB_128_BIT_MACS	- 128 bit macs instead of 80
1777  * BCH_SB_ENCRYPTION_TYPE - if nonzero encryption is enabled; overrides
1778  *			   DATA/META_CSUM_TYPE. Also indicates encryption
1779  *			   algorithm in use, if/when we get more than one
1780  */
1781 
1782 LE16_BITMASK(BCH_SB_BLOCK_SIZE,		struct bch_sb, block_size, 0, 16);
1783 
1784 LE64_BITMASK(BCH_SB_INITIALIZED,	struct bch_sb, flags[0],  0,  1);
1785 LE64_BITMASK(BCH_SB_CLEAN,		struct bch_sb, flags[0],  1,  2);
1786 LE64_BITMASK(BCH_SB_CSUM_TYPE,		struct bch_sb, flags[0],  2,  8);
1787 LE64_BITMASK(BCH_SB_ERROR_ACTION,	struct bch_sb, flags[0],  8, 12);
1788 
1789 LE64_BITMASK(BCH_SB_BTREE_NODE_SIZE,	struct bch_sb, flags[0], 12, 28);
1790 
1791 LE64_BITMASK(BCH_SB_GC_RESERVE,		struct bch_sb, flags[0], 28, 33);
1792 LE64_BITMASK(BCH_SB_ROOT_RESERVE,	struct bch_sb, flags[0], 33, 40);
1793 
1794 LE64_BITMASK(BCH_SB_META_CSUM_TYPE,	struct bch_sb, flags[0], 40, 44);
1795 LE64_BITMASK(BCH_SB_DATA_CSUM_TYPE,	struct bch_sb, flags[0], 44, 48);
1796 
1797 LE64_BITMASK(BCH_SB_META_REPLICAS_WANT,	struct bch_sb, flags[0], 48, 52);
1798 LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT,	struct bch_sb, flags[0], 52, 56);
1799 
1800 LE64_BITMASK(BCH_SB_POSIX_ACL,		struct bch_sb, flags[0], 56, 57);
1801 LE64_BITMASK(BCH_SB_USRQUOTA,		struct bch_sb, flags[0], 57, 58);
1802 LE64_BITMASK(BCH_SB_GRPQUOTA,		struct bch_sb, flags[0], 58, 59);
1803 LE64_BITMASK(BCH_SB_PRJQUOTA,		struct bch_sb, flags[0], 59, 60);
1804 
1805 LE64_BITMASK(BCH_SB_HAS_ERRORS,		struct bch_sb, flags[0], 60, 61);
1806 LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
1807 
1808 LE64_BITMASK(BCH_SB_BIG_ENDIAN,		struct bch_sb, flags[0], 62, 63);
1809 
1810 LE64_BITMASK(BCH_SB_STR_HASH_TYPE,	struct bch_sb, flags[1],  0,  4);
1811 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_LO,struct bch_sb, flags[1],  4,  8);
1812 LE64_BITMASK(BCH_SB_INODE_32BIT,	struct bch_sb, flags[1],  8,  9);
1813 
1814 LE64_BITMASK(BCH_SB_128_BIT_MACS,	struct bch_sb, flags[1],  9, 10);
1815 LE64_BITMASK(BCH_SB_ENCRYPTION_TYPE,	struct bch_sb, flags[1], 10, 14);
1816 
1817 /*
1818  * Max size of an extent that may require bouncing to read or write
1819  * (checksummed, compressed): 64k
1820  */
1821 LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
1822 					struct bch_sb, flags[1], 14, 20);
1823 
1824 LE64_BITMASK(BCH_SB_META_REPLICAS_REQ,	struct bch_sb, flags[1], 20, 24);
1825 LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ,	struct bch_sb, flags[1], 24, 28);
1826 
1827 LE64_BITMASK(BCH_SB_PROMOTE_TARGET,	struct bch_sb, flags[1], 28, 40);
1828 LE64_BITMASK(BCH_SB_FOREGROUND_TARGET,	struct bch_sb, flags[1], 40, 52);
1829 LE64_BITMASK(BCH_SB_BACKGROUND_TARGET,	struct bch_sb, flags[1], 52, 64);
1830 
1831 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO,
1832 					struct bch_sb, flags[2],  0,  4);
1833 LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES,	struct bch_sb, flags[2],  4, 64);
1834 
1835 LE64_BITMASK(BCH_SB_ERASURE_CODE,	struct bch_sb, flags[3],  0, 16);
1836 LE64_BITMASK(BCH_SB_METADATA_TARGET,	struct bch_sb, flags[3], 16, 28);
1837 LE64_BITMASK(BCH_SB_SHARD_INUMS,	struct bch_sb, flags[3], 28, 29);
1838 LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
1839 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
1840 LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
1841 LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
1842 LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
1843 LE64_BITMASK(BCH_SB_NOCOW,		struct bch_sb, flags[4], 33, 34);
1844 LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE,	struct bch_sb, flags[4], 34, 54);
1845 LE64_BITMASK(BCH_SB_VERSION_UPGRADE,	struct bch_sb, flags[4], 54, 56);
1846 
1847 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE_HI,struct bch_sb, flags[4], 56, 60);
1848 LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI,
1849 					struct bch_sb, flags[4], 60, 64);
1850 
1851 LE64_BITMASK(BCH_SB_VERSION_UPGRADE_COMPLETE,
1852 					struct bch_sb, flags[5],  0, 16);
1853 
1854 static inline __u64 BCH_SB_COMPRESSION_TYPE(const struct bch_sb *sb)
1855 {
1856 	return BCH_SB_COMPRESSION_TYPE_LO(sb) | (BCH_SB_COMPRESSION_TYPE_HI(sb) << 4);
1857 }
1858 
1859 static inline void SET_BCH_SB_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
1860 {
1861 	SET_BCH_SB_COMPRESSION_TYPE_LO(sb, v);
1862 	SET_BCH_SB_COMPRESSION_TYPE_HI(sb, v >> 4);
1863 }
1864 
1865 static inline __u64 BCH_SB_BACKGROUND_COMPRESSION_TYPE(const struct bch_sb *sb)
1866 {
1867 	return BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb) |
1868 		(BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb) << 4);
1869 }
1870 
1871 static inline void SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE(struct bch_sb *sb, __u64 v)
1872 {
1873 	SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_LO(sb, v);
1874 	SET_BCH_SB_BACKGROUND_COMPRESSION_TYPE_HI(sb, v >> 4);
1875 }
1876 
1877 /*
1878  * Features:
1879  *
1880  * journal_seq_blacklist_v3:	gates BCH_SB_FIELD_journal_seq_blacklist
1881  * reflink:			gates KEY_TYPE_reflink
1882  * inline_data:			gates KEY_TYPE_inline_data
1883  * new_siphash:			gates BCH_STR_HASH_siphash
1884  * new_extent_overwrite:	gates BTREE_NODE_NEW_EXTENT_OVERWRITE
1885  */
1886 #define BCH_SB_FEATURES()			\
1887 	x(lz4,				0)	\
1888 	x(gzip,				1)	\
1889 	x(zstd,				2)	\
1890 	x(atomic_nlink,			3)	\
1891 	x(ec,				4)	\
1892 	x(journal_seq_blacklist_v3,	5)	\
1893 	x(reflink,			6)	\
1894 	x(new_siphash,			7)	\
1895 	x(inline_data,			8)	\
1896 	x(new_extent_overwrite,		9)	\
1897 	x(incompressible,		10)	\
1898 	x(btree_ptr_v2,			11)	\
1899 	x(extents_above_btree_updates,	12)	\
1900 	x(btree_updates_journalled,	13)	\
1901 	x(reflink_inline_data,		14)	\
1902 	x(new_varint,			15)	\
1903 	x(journal_no_flush,		16)	\
1904 	x(alloc_v2,			17)	\
1905 	x(extents_across_btree_nodes,	18)
1906 
1907 #define BCH_SB_FEATURES_ALWAYS				\
1908 	((1ULL << BCH_FEATURE_new_extent_overwrite)|	\
1909 	 (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
1910 	 (1ULL << BCH_FEATURE_btree_updates_journalled)|\
1911 	 (1ULL << BCH_FEATURE_alloc_v2)|\
1912 	 (1ULL << BCH_FEATURE_extents_across_btree_nodes))
1913 
1914 #define BCH_SB_FEATURES_ALL				\
1915 	(BCH_SB_FEATURES_ALWAYS|			\
1916 	 (1ULL << BCH_FEATURE_new_siphash)|		\
1917 	 (1ULL << BCH_FEATURE_btree_ptr_v2)|		\
1918 	 (1ULL << BCH_FEATURE_new_varint)|		\
1919 	 (1ULL << BCH_FEATURE_journal_no_flush))
1920 
1921 enum bch_sb_feature {
1922 #define x(f, n) BCH_FEATURE_##f,
1923 	BCH_SB_FEATURES()
1924 #undef x
1925 	BCH_FEATURE_NR,
1926 };
1927 
1928 #define BCH_SB_COMPAT()					\
1929 	x(alloc_info,				0)	\
1930 	x(alloc_metadata,			1)	\
1931 	x(extents_above_btree_updates_done,	2)	\
1932 	x(bformat_overflow_done,		3)
1933 
1934 enum bch_sb_compat {
1935 #define x(f, n) BCH_COMPAT_##f,
1936 	BCH_SB_COMPAT()
1937 #undef x
1938 	BCH_COMPAT_NR,
1939 };
1940 
1941 /* options: */
1942 
1943 #define BCH_VERSION_UPGRADE_OPTS()	\
1944 	x(compatible,		0)	\
1945 	x(incompatible,		1)	\
1946 	x(none,			2)
1947 
1948 enum bch_version_upgrade_opts {
1949 #define x(t, n) BCH_VERSION_UPGRADE_##t = n,
1950 	BCH_VERSION_UPGRADE_OPTS()
1951 #undef x
1952 };
1953 
1954 #define BCH_REPLICAS_MAX		4U
1955 
1956 #define BCH_BKEY_PTRS_MAX		16U
1957 
1958 #define BCH_ERROR_ACTIONS()		\
1959 	x(continue,		0)	\
1960 	x(ro,			1)	\
1961 	x(panic,		2)
1962 
1963 enum bch_error_actions {
1964 #define x(t, n) BCH_ON_ERROR_##t = n,
1965 	BCH_ERROR_ACTIONS()
1966 #undef x
1967 	BCH_ON_ERROR_NR
1968 };
1969 
1970 #define BCH_STR_HASH_TYPES()		\
1971 	x(crc32c,		0)	\
1972 	x(crc64,		1)	\
1973 	x(siphash_old,		2)	\
1974 	x(siphash,		3)
1975 
1976 enum bch_str_hash_type {
1977 #define x(t, n) BCH_STR_HASH_##t = n,
1978 	BCH_STR_HASH_TYPES()
1979 #undef x
1980 	BCH_STR_HASH_NR
1981 };
1982 
1983 #define BCH_STR_HASH_OPTS()		\
1984 	x(crc32c,		0)	\
1985 	x(crc64,		1)	\
1986 	x(siphash,		2)
1987 
1988 enum bch_str_hash_opts {
1989 #define x(t, n) BCH_STR_HASH_OPT_##t = n,
1990 	BCH_STR_HASH_OPTS()
1991 #undef x
1992 	BCH_STR_HASH_OPT_NR
1993 };
1994 
1995 #define BCH_CSUM_TYPES()			\
1996 	x(none,				0)	\
1997 	x(crc32c_nonzero,		1)	\
1998 	x(crc64_nonzero,		2)	\
1999 	x(chacha20_poly1305_80,		3)	\
2000 	x(chacha20_poly1305_128,	4)	\
2001 	x(crc32c,			5)	\
2002 	x(crc64,			6)	\
2003 	x(xxhash,			7)
2004 
2005 enum bch_csum_type {
2006 #define x(t, n) BCH_CSUM_##t = n,
2007 	BCH_CSUM_TYPES()
2008 #undef x
2009 	BCH_CSUM_NR
2010 };
2011 
2012 static const __maybe_unused unsigned bch_crc_bytes[] = {
2013 	[BCH_CSUM_none]				= 0,
2014 	[BCH_CSUM_crc32c_nonzero]		= 4,
2015 	[BCH_CSUM_crc32c]			= 4,
2016 	[BCH_CSUM_crc64_nonzero]		= 8,
2017 	[BCH_CSUM_crc64]			= 8,
2018 	[BCH_CSUM_xxhash]			= 8,
2019 	[BCH_CSUM_chacha20_poly1305_80]		= 10,
2020 	[BCH_CSUM_chacha20_poly1305_128]	= 16,
2021 };
2022 
2023 static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
2024 {
2025 	switch (type) {
2026 	case BCH_CSUM_chacha20_poly1305_80:
2027 	case BCH_CSUM_chacha20_poly1305_128:
2028 		return true;
2029 	default:
2030 		return false;
2031 	}
2032 }
2033 
2034 #define BCH_CSUM_OPTS()			\
2035 	x(none,			0)	\
2036 	x(crc32c,		1)	\
2037 	x(crc64,		2)	\
2038 	x(xxhash,		3)
2039 
2040 enum bch_csum_opts {
2041 #define x(t, n) BCH_CSUM_OPT_##t = n,
2042 	BCH_CSUM_OPTS()
2043 #undef x
2044 	BCH_CSUM_OPT_NR
2045 };
2046 
2047 #define BCH_COMPRESSION_TYPES()		\
2048 	x(none,			0)	\
2049 	x(lz4_old,		1)	\
2050 	x(gzip,			2)	\
2051 	x(lz4,			3)	\
2052 	x(zstd,			4)	\
2053 	x(incompressible,	5)
2054 
2055 enum bch_compression_type {
2056 #define x(t, n) BCH_COMPRESSION_TYPE_##t = n,
2057 	BCH_COMPRESSION_TYPES()
2058 #undef x
2059 	BCH_COMPRESSION_TYPE_NR
2060 };
2061 
2062 #define BCH_COMPRESSION_OPTS()		\
2063 	x(none,		0)		\
2064 	x(lz4,		1)		\
2065 	x(gzip,		2)		\
2066 	x(zstd,		3)
2067 
2068 enum bch_compression_opts {
2069 #define x(t, n) BCH_COMPRESSION_OPT_##t = n,
2070 	BCH_COMPRESSION_OPTS()
2071 #undef x
2072 	BCH_COMPRESSION_OPT_NR
2073 };
2074 
2075 /*
2076  * Magic numbers
2077  *
2078  * The various other data structures have their own magic numbers, which are
2079  * xored with the first part of the cache set's UUID
2080  */
2081 
2082 #define BCACHE_MAGIC							\
2083 	UUID_INIT(0xc68573f6, 0x4e1a, 0x45ca,				\
2084 		  0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81)
2085 #define BCHFS_MAGIC							\
2086 	UUID_INIT(0xc68573f6, 0x66ce, 0x90a9,				\
2087 		  0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
2088 
2089 #define BCACHEFS_STATFS_MAGIC		0xca451a4e
2090 
2091 #define JSET_MAGIC		__cpu_to_le64(0x245235c1a3625032ULL)
2092 #define BSET_MAGIC		__cpu_to_le64(0x90135c78b99e07f5ULL)
2093 
2094 static inline __le64 __bch2_sb_magic(struct bch_sb *sb)
2095 {
2096 	__le64 ret;
2097 
2098 	memcpy(&ret, &sb->uuid, sizeof(ret));
2099 	return ret;
2100 }
2101 
2102 static inline __u64 __jset_magic(struct bch_sb *sb)
2103 {
2104 	return __le64_to_cpu(__bch2_sb_magic(sb) ^ JSET_MAGIC);
2105 }
2106 
2107 static inline __u64 __bset_magic(struct bch_sb *sb)
2108 {
2109 	return __le64_to_cpu(__bch2_sb_magic(sb) ^ BSET_MAGIC);
2110 }
2111 
2112 /* Journal */
2113 
2114 #define JSET_KEYS_U64s	(sizeof(struct jset_entry) / sizeof(__u64))
2115 
2116 #define BCH_JSET_ENTRY_TYPES()			\
2117 	x(btree_keys,		0)		\
2118 	x(btree_root,		1)		\
2119 	x(prio_ptrs,		2)		\
2120 	x(blacklist,		3)		\
2121 	x(blacklist_v2,		4)		\
2122 	x(usage,		5)		\
2123 	x(data_usage,		6)		\
2124 	x(clock,		7)		\
2125 	x(dev_usage,		8)		\
2126 	x(log,			9)		\
2127 	x(overwrite,		10)
2128 
2129 enum {
2130 #define x(f, nr)	BCH_JSET_ENTRY_##f	= nr,
2131 	BCH_JSET_ENTRY_TYPES()
2132 #undef x
2133 	BCH_JSET_ENTRY_NR
2134 };
2135 
2136 /*
2137  * Journal sequence numbers can be blacklisted: bsets record the max sequence
2138  * number of all the journal entries they contain updates for, so that on
2139  * recovery we can ignore those bsets that contain index updates newer that what
2140  * made it into the journal.
2141  *
2142  * This means that we can't reuse that journal_seq - we have to skip it, and
2143  * then record that we skipped it so that the next time we crash and recover we
2144  * don't think there was a missing journal entry.
2145  */
2146 struct jset_entry_blacklist {
2147 	struct jset_entry	entry;
2148 	__le64			seq;
2149 };
2150 
2151 struct jset_entry_blacklist_v2 {
2152 	struct jset_entry	entry;
2153 	__le64			start;
2154 	__le64			end;
2155 };
2156 
2157 #define BCH_FS_USAGE_TYPES()			\
2158 	x(reserved,		0)		\
2159 	x(inodes,		1)		\
2160 	x(key_version,		2)
2161 
2162 enum {
2163 #define x(f, nr)	BCH_FS_USAGE_##f	= nr,
2164 	BCH_FS_USAGE_TYPES()
2165 #undef x
2166 	BCH_FS_USAGE_NR
2167 };
2168 
2169 struct jset_entry_usage {
2170 	struct jset_entry	entry;
2171 	__le64			v;
2172 } __packed;
2173 
2174 struct jset_entry_data_usage {
2175 	struct jset_entry	entry;
2176 	__le64			v;
2177 	struct bch_replicas_entry r;
2178 } __packed;
2179 
2180 struct jset_entry_clock {
2181 	struct jset_entry	entry;
2182 	__u8			rw;
2183 	__u8			pad[7];
2184 	__le64			time;
2185 } __packed;
2186 
2187 struct jset_entry_dev_usage_type {
2188 	__le64			buckets;
2189 	__le64			sectors;
2190 	__le64			fragmented;
2191 } __packed;
2192 
2193 struct jset_entry_dev_usage {
2194 	struct jset_entry	entry;
2195 	__le32			dev;
2196 	__u32			pad;
2197 
2198 	__le64			buckets_ec;
2199 	__le64			_buckets_unavailable; /* No longer used */
2200 
2201 	struct jset_entry_dev_usage_type d[];
2202 };
2203 
2204 static inline unsigned jset_entry_dev_usage_nr_types(struct jset_entry_dev_usage *u)
2205 {
2206 	return (vstruct_bytes(&u->entry) - sizeof(struct jset_entry_dev_usage)) /
2207 		sizeof(struct jset_entry_dev_usage_type);
2208 }
2209 
2210 struct jset_entry_log {
2211 	struct jset_entry	entry;
2212 	u8			d[];
2213 } __packed;
2214 
2215 /*
2216  * On disk format for a journal entry:
2217  * seq is monotonically increasing; every journal entry has its own unique
2218  * sequence number.
2219  *
2220  * last_seq is the oldest journal entry that still has keys the btree hasn't
2221  * flushed to disk yet.
2222  *
2223  * version is for on disk format changes.
2224  */
2225 struct jset {
2226 	struct bch_csum		csum;
2227 
2228 	__le64			magic;
2229 	__le64			seq;
2230 	__le32			version;
2231 	__le32			flags;
2232 
2233 	__le32			u64s; /* size of d[] in u64s */
2234 
2235 	__u8			encrypted_start[0];
2236 
2237 	__le16			_read_clock; /* no longer used */
2238 	__le16			_write_clock;
2239 
2240 	/* Sequence number of oldest dirty journal entry */
2241 	__le64			last_seq;
2242 
2243 
2244 	struct jset_entry	start[0];
2245 	__u64			_data[];
2246 } __packed __aligned(8);
2247 
2248 LE32_BITMASK(JSET_CSUM_TYPE,	struct jset, flags, 0, 4);
2249 LE32_BITMASK(JSET_BIG_ENDIAN,	struct jset, flags, 4, 5);
2250 LE32_BITMASK(JSET_NO_FLUSH,	struct jset, flags, 5, 6);
2251 
2252 #define BCH_JOURNAL_BUCKETS_MIN		8
2253 
2254 /* Btree: */
2255 
2256 enum btree_id_flags {
2257 	BTREE_ID_EXTENTS	= BIT(0),
2258 	BTREE_ID_SNAPSHOTS	= BIT(1),
2259 	BTREE_ID_SNAPSHOT_FIELD	= BIT(2),
2260 	BTREE_ID_DATA		= BIT(3),
2261 };
2262 
2263 #define BCH_BTREE_IDS()								\
2264 	x(extents,		0,	BTREE_ID_EXTENTS|BTREE_ID_SNAPSHOTS|BTREE_ID_DATA,\
2265 	  BIT_ULL(KEY_TYPE_whiteout)|						\
2266 	  BIT_ULL(KEY_TYPE_error)|						\
2267 	  BIT_ULL(KEY_TYPE_cookie)|						\
2268 	  BIT_ULL(KEY_TYPE_extent)|						\
2269 	  BIT_ULL(KEY_TYPE_reservation)|					\
2270 	  BIT_ULL(KEY_TYPE_reflink_p)|						\
2271 	  BIT_ULL(KEY_TYPE_inline_data))					\
2272 	x(inodes,		1,	BTREE_ID_SNAPSHOTS,			\
2273 	  BIT_ULL(KEY_TYPE_whiteout)|						\
2274 	  BIT_ULL(KEY_TYPE_inode)|						\
2275 	  BIT_ULL(KEY_TYPE_inode_v2)|						\
2276 	  BIT_ULL(KEY_TYPE_inode_v3)|						\
2277 	  BIT_ULL(KEY_TYPE_inode_generation))					\
2278 	x(dirents,		2,	BTREE_ID_SNAPSHOTS,			\
2279 	  BIT_ULL(KEY_TYPE_whiteout)|						\
2280 	  BIT_ULL(KEY_TYPE_hash_whiteout)|					\
2281 	  BIT_ULL(KEY_TYPE_dirent))						\
2282 	x(xattrs,		3,	BTREE_ID_SNAPSHOTS,			\
2283 	  BIT_ULL(KEY_TYPE_whiteout)|						\
2284 	  BIT_ULL(KEY_TYPE_cookie)|						\
2285 	  BIT_ULL(KEY_TYPE_hash_whiteout)|					\
2286 	  BIT_ULL(KEY_TYPE_xattr))						\
2287 	x(alloc,		4,	0,					\
2288 	  BIT_ULL(KEY_TYPE_alloc)|						\
2289 	  BIT_ULL(KEY_TYPE_alloc_v2)|						\
2290 	  BIT_ULL(KEY_TYPE_alloc_v3)|						\
2291 	  BIT_ULL(KEY_TYPE_alloc_v4))						\
2292 	x(quotas,		5,	0,					\
2293 	  BIT_ULL(KEY_TYPE_quota))						\
2294 	x(stripes,		6,	0,					\
2295 	  BIT_ULL(KEY_TYPE_stripe))						\
2296 	x(reflink,		7,	BTREE_ID_EXTENTS|BTREE_ID_DATA,		\
2297 	  BIT_ULL(KEY_TYPE_reflink_v)|						\
2298 	  BIT_ULL(KEY_TYPE_indirect_inline_data))				\
2299 	x(subvolumes,		8,	0,					\
2300 	  BIT_ULL(KEY_TYPE_subvolume))						\
2301 	x(snapshots,		9,	0,					\
2302 	  BIT_ULL(KEY_TYPE_snapshot))						\
2303 	x(lru,			10,	0,					\
2304 	  BIT_ULL(KEY_TYPE_set))						\
2305 	x(freespace,		11,	BTREE_ID_EXTENTS,			\
2306 	  BIT_ULL(KEY_TYPE_set))						\
2307 	x(need_discard,		12,	0,					\
2308 	  BIT_ULL(KEY_TYPE_set))						\
2309 	x(backpointers,		13,	0,					\
2310 	  BIT_ULL(KEY_TYPE_backpointer))					\
2311 	x(bucket_gens,		14,	0,					\
2312 	  BIT_ULL(KEY_TYPE_bucket_gens))					\
2313 	x(snapshot_trees,	15,	0,					\
2314 	  BIT_ULL(KEY_TYPE_snapshot_tree))					\
2315 	x(deleted_inodes,	16,	BTREE_ID_SNAPSHOT_FIELD,		\
2316 	  BIT_ULL(KEY_TYPE_set))						\
2317 	x(logged_ops,		17,	0,					\
2318 	  BIT_ULL(KEY_TYPE_logged_op_truncate)|					\
2319 	  BIT_ULL(KEY_TYPE_logged_op_finsert))					\
2320 	x(rebalance_work,	18,	BTREE_ID_SNAPSHOT_FIELD,		\
2321 	  BIT_ULL(KEY_TYPE_set)|BIT_ULL(KEY_TYPE_cookie))
2322 
2323 enum btree_id {
2324 #define x(name, nr, ...) BTREE_ID_##name = nr,
2325 	BCH_BTREE_IDS()
2326 #undef x
2327 	BTREE_ID_NR
2328 };
2329 
2330 #define BTREE_MAX_DEPTH		4U
2331 
2332 /* Btree nodes */
2333 
2334 /*
2335  * Btree nodes
2336  *
2337  * On disk a btree node is a list/log of these; within each set the keys are
2338  * sorted
2339  */
2340 struct bset {
2341 	__le64			seq;
2342 
2343 	/*
2344 	 * Highest journal entry this bset contains keys for.
2345 	 * If on recovery we don't see that journal entry, this bset is ignored:
2346 	 * this allows us to preserve the order of all index updates after a
2347 	 * crash, since the journal records a total order of all index updates
2348 	 * and anything that didn't make it to the journal doesn't get used.
2349 	 */
2350 	__le64			journal_seq;
2351 
2352 	__le32			flags;
2353 	__le16			version;
2354 	__le16			u64s; /* count of d[] in u64s */
2355 
2356 	struct bkey_packed	start[0];
2357 	__u64			_data[];
2358 } __packed __aligned(8);
2359 
2360 LE32_BITMASK(BSET_CSUM_TYPE,	struct bset, flags, 0, 4);
2361 
2362 LE32_BITMASK(BSET_BIG_ENDIAN,	struct bset, flags, 4, 5);
2363 LE32_BITMASK(BSET_SEPARATE_WHITEOUTS,
2364 				struct bset, flags, 5, 6);
2365 
2366 /* Sector offset within the btree node: */
2367 LE32_BITMASK(BSET_OFFSET,	struct bset, flags, 16, 32);
2368 
2369 struct btree_node {
2370 	struct bch_csum		csum;
2371 	__le64			magic;
2372 
2373 	/* this flags field is encrypted, unlike bset->flags: */
2374 	__le64			flags;
2375 
2376 	/* Closed interval: */
2377 	struct bpos		min_key;
2378 	struct bpos		max_key;
2379 	struct bch_extent_ptr	_ptr; /* not used anymore */
2380 	struct bkey_format	format;
2381 
2382 	union {
2383 	struct bset		keys;
2384 	struct {
2385 		__u8		pad[22];
2386 		__le16		u64s;
2387 		__u64		_data[0];
2388 
2389 	};
2390 	};
2391 } __packed __aligned(8);
2392 
2393 LE64_BITMASK(BTREE_NODE_ID_LO,	struct btree_node, flags,  0,  4);
2394 LE64_BITMASK(BTREE_NODE_LEVEL,	struct btree_node, flags,  4,  8);
2395 LE64_BITMASK(BTREE_NODE_NEW_EXTENT_OVERWRITE,
2396 				struct btree_node, flags,  8,  9);
2397 LE64_BITMASK(BTREE_NODE_ID_HI,	struct btree_node, flags,  9, 25);
2398 /* 25-32 unused */
2399 LE64_BITMASK(BTREE_NODE_SEQ,	struct btree_node, flags, 32, 64);
2400 
2401 static inline __u64 BTREE_NODE_ID(struct btree_node *n)
2402 {
2403 	return BTREE_NODE_ID_LO(n) | (BTREE_NODE_ID_HI(n) << 4);
2404 }
2405 
2406 static inline void SET_BTREE_NODE_ID(struct btree_node *n, __u64 v)
2407 {
2408 	SET_BTREE_NODE_ID_LO(n, v);
2409 	SET_BTREE_NODE_ID_HI(n, v >> 4);
2410 }
2411 
2412 struct btree_node_entry {
2413 	struct bch_csum		csum;
2414 
2415 	union {
2416 	struct bset		keys;
2417 	struct {
2418 		__u8		pad[22];
2419 		__le16		u64s;
2420 		__u64		_data[0];
2421 	};
2422 	};
2423 } __packed __aligned(8);
2424 
2425 #endif /* _BCACHEFS_FORMAT_H */
2426