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1// SPDX-License-Identifier: GPL-2.0
2
3#include "bcachefs.h"
4#include "bkey.h"
5#include "bkey_cmp.h"
6#include "bkey_methods.h"
7#include "bset.h"
8#include "util.h"
9
10const struct bkey_format bch2_bkey_format_current = BKEY_FORMAT_CURRENT;
11
12void bch2_bkey_packed_to_binary_text(struct printbuf *out,
13 const struct bkey_format *f,
14 const struct bkey_packed *k)
15{
16 const u64 *p = high_word(f, k);
17 unsigned word_bits = 64 - high_bit_offset;
18 unsigned nr_key_bits = bkey_format_key_bits(f) + high_bit_offset;
19 u64 v = *p & (~0ULL >> high_bit_offset);
20
21 if (!nr_key_bits) {
22 prt_str(out, "(empty)");
23 return;
24 }
25
26 while (1) {
27 unsigned next_key_bits = nr_key_bits;
28
29 if (nr_key_bits < 64) {
30 v >>= 64 - nr_key_bits;
31 next_key_bits = 0;
32 } else {
33 next_key_bits -= 64;
34 }
35
36 bch2_prt_u64_base2_nbits(out, v, min(word_bits, nr_key_bits));
37
38 if (!next_key_bits)
39 break;
40
41 prt_char(out, ' ');
42
43 p = next_word(p);
44 v = *p;
45 word_bits = 64;
46 nr_key_bits = next_key_bits;
47 }
48}
49
50#ifdef CONFIG_BCACHEFS_DEBUG
51
52static void bch2_bkey_pack_verify(const struct bkey_packed *packed,
53 const struct bkey *unpacked,
54 const struct bkey_format *format)
55{
56 struct bkey tmp;
57
58 BUG_ON(bkeyp_val_u64s(format, packed) !=
59 bkey_val_u64s(unpacked));
60
61 BUG_ON(packed->u64s < bkeyp_key_u64s(format, packed));
62
63 tmp = __bch2_bkey_unpack_key(format, packed);
64
65 if (memcmp(&tmp, unpacked, sizeof(struct bkey))) {
66 struct printbuf buf = PRINTBUF;
67
68 prt_printf(&buf, "keys differ: format u64s %u fields %u %u %u %u %u\n",
69 format->key_u64s,
70 format->bits_per_field[0],
71 format->bits_per_field[1],
72 format->bits_per_field[2],
73 format->bits_per_field[3],
74 format->bits_per_field[4]);
75
76 prt_printf(&buf, "compiled unpack: ");
77 bch2_bkey_to_text(&buf, unpacked);
78 prt_newline(&buf);
79
80 prt_printf(&buf, "c unpack: ");
81 bch2_bkey_to_text(&buf, &tmp);
82 prt_newline(&buf);
83
84 prt_printf(&buf, "compiled unpack: ");
85 bch2_bkey_packed_to_binary_text(&buf, &bch2_bkey_format_current,
86 (struct bkey_packed *) unpacked);
87 prt_newline(&buf);
88
89 prt_printf(&buf, "c unpack: ");
90 bch2_bkey_packed_to_binary_text(&buf, &bch2_bkey_format_current,
91 (struct bkey_packed *) &tmp);
92 prt_newline(&buf);
93
94 panic("%s", buf.buf);
95 }
96}
97
98#else
99static inline void bch2_bkey_pack_verify(const struct bkey_packed *packed,
100 const struct bkey *unpacked,
101 const struct bkey_format *format) {}
102#endif
103
104struct pack_state {
105 const struct bkey_format *format;
106 unsigned bits; /* bits remaining in current word */
107 u64 w; /* current word */
108 u64 *p; /* pointer to next word */
109};
110
111__always_inline
112static struct pack_state pack_state_init(const struct bkey_format *format,
113 struct bkey_packed *k)
114{
115 u64 *p = high_word(format, k);
116
117 return (struct pack_state) {
118 .format = format,
119 .bits = 64 - high_bit_offset,
120 .w = 0,
121 .p = p,
122 };
123}
124
125__always_inline
126static void pack_state_finish(struct pack_state *state,
127 struct bkey_packed *k)
128{
129 EBUG_ON(state->p < k->_data);
130 EBUG_ON(state->p >= (u64 *) k->_data + state->format->key_u64s);
131
132 *state->p = state->w;
133}
134
135struct unpack_state {
136 const struct bkey_format *format;
137 unsigned bits; /* bits remaining in current word */
138 u64 w; /* current word */
139 const u64 *p; /* pointer to next word */
140};
141
142__always_inline
143static struct unpack_state unpack_state_init(const struct bkey_format *format,
144 const struct bkey_packed *k)
145{
146 const u64 *p = high_word(format, k);
147
148 return (struct unpack_state) {
149 .format = format,
150 .bits = 64 - high_bit_offset,
151 .w = *p << high_bit_offset,
152 .p = p,
153 };
154}
155
156__always_inline
157static u64 get_inc_field(struct unpack_state *state, unsigned field)
158{
159 unsigned bits = state->format->bits_per_field[field];
160 u64 v = 0, offset = le64_to_cpu(state->format->field_offset[field]);
161
162 if (bits >= state->bits) {
163 v = state->w >> (64 - bits);
164 bits -= state->bits;
165
166 state->p = next_word(state->p);
167 state->w = *state->p;
168 state->bits = 64;
169 }
170
171 /* avoid shift by 64 if bits is 0 - bits is never 64 here: */
172 v |= (state->w >> 1) >> (63 - bits);
173 state->w <<= bits;
174 state->bits -= bits;
175
176 return v + offset;
177}
178
179__always_inline
180static void __set_inc_field(struct pack_state *state, unsigned field, u64 v)
181{
182 unsigned bits = state->format->bits_per_field[field];
183
184 if (bits) {
185 if (bits > state->bits) {
186 bits -= state->bits;
187 /* avoid shift by 64 if bits is 64 - bits is never 0 here: */
188 state->w |= (v >> 1) >> (bits - 1);
189
190 *state->p = state->w;
191 state->p = next_word(state->p);
192 state->w = 0;
193 state->bits = 64;
194 }
195
196 state->bits -= bits;
197 state->w |= v << state->bits;
198 }
199}
200
201__always_inline
202static bool set_inc_field(struct pack_state *state, unsigned field, u64 v)
203{
204 unsigned bits = state->format->bits_per_field[field];
205 u64 offset = le64_to_cpu(state->format->field_offset[field]);
206
207 if (v < offset)
208 return false;
209
210 v -= offset;
211
212 if (fls64(v) > bits)
213 return false;
214
215 __set_inc_field(state, field, v);
216 return true;
217}
218
219/*
220 * Note: does NOT set out->format (we don't know what it should be here!)
221 *
222 * Also: doesn't work on extents - it doesn't preserve the invariant that
223 * if k is packed bkey_start_pos(k) will successfully pack
224 */
225static bool bch2_bkey_transform_key(const struct bkey_format *out_f,
226 struct bkey_packed *out,
227 const struct bkey_format *in_f,
228 const struct bkey_packed *in)
229{
230 struct pack_state out_s = pack_state_init(out_f, out);
231 struct unpack_state in_s = unpack_state_init(in_f, in);
232 u64 *w = out->_data;
233 unsigned i;
234
235 *w = 0;
236
237 for (i = 0; i < BKEY_NR_FIELDS; i++)
238 if (!set_inc_field(&out_s, i, get_inc_field(&in_s, i)))
239 return false;
240
241 /* Can't happen because the val would be too big to unpack: */
242 EBUG_ON(in->u64s - in_f->key_u64s + out_f->key_u64s > U8_MAX);
243
244 pack_state_finish(&out_s, out);
245 out->u64s = out_f->key_u64s + in->u64s - in_f->key_u64s;
246 out->needs_whiteout = in->needs_whiteout;
247 out->type = in->type;
248
249 return true;
250}
251
252bool bch2_bkey_transform(const struct bkey_format *out_f,
253 struct bkey_packed *out,
254 const struct bkey_format *in_f,
255 const struct bkey_packed *in)
256{
257 if (!bch2_bkey_transform_key(out_f, out, in_f, in))
258 return false;
259
260 memcpy_u64s((u64 *) out + out_f->key_u64s,
261 (u64 *) in + in_f->key_u64s,
262 (in->u64s - in_f->key_u64s));
263 return true;
264}
265
266struct bkey __bch2_bkey_unpack_key(const struct bkey_format *format,
267 const struct bkey_packed *in)
268{
269 struct unpack_state state = unpack_state_init(format, in);
270 struct bkey out;
271
272 EBUG_ON(format->nr_fields != BKEY_NR_FIELDS);
273 EBUG_ON(in->u64s < format->key_u64s);
274 EBUG_ON(in->format != KEY_FORMAT_LOCAL_BTREE);
275 EBUG_ON(in->u64s - format->key_u64s + BKEY_U64s > U8_MAX);
276
277 out.u64s = BKEY_U64s + in->u64s - format->key_u64s;
278 out.format = KEY_FORMAT_CURRENT;
279 out.needs_whiteout = in->needs_whiteout;
280 out.type = in->type;
281 out.pad[0] = 0;
282
283#define x(id, field) out.field = get_inc_field(&state, id);
284 bkey_fields()
285#undef x
286
287 return out;
288}
289
290#ifndef HAVE_BCACHEFS_COMPILED_UNPACK
291struct bpos __bkey_unpack_pos(const struct bkey_format *format,
292 const struct bkey_packed *in)
293{
294 struct unpack_state state = unpack_state_init(format, in);
295 struct bpos out;
296
297 EBUG_ON(format->nr_fields != BKEY_NR_FIELDS);
298 EBUG_ON(in->u64s < format->key_u64s);
299 EBUG_ON(in->format != KEY_FORMAT_LOCAL_BTREE);
300
301 out.inode = get_inc_field(&state, BKEY_FIELD_INODE);
302 out.offset = get_inc_field(&state, BKEY_FIELD_OFFSET);
303 out.snapshot = get_inc_field(&state, BKEY_FIELD_SNAPSHOT);
304
305 return out;
306}
307#endif
308
309/**
310 * bch2_bkey_pack_key -- pack just the key, not the value
311 * @out: packed result
312 * @in: key to pack
313 * @format: format of packed result
314 *
315 * Returns: true on success, false on failure
316 */
317bool bch2_bkey_pack_key(struct bkey_packed *out, const struct bkey *in,
318 const struct bkey_format *format)
319{
320 struct pack_state state = pack_state_init(format, out);
321 u64 *w = out->_data;
322
323 EBUG_ON((void *) in == (void *) out);
324 EBUG_ON(format->nr_fields != BKEY_NR_FIELDS);
325 EBUG_ON(in->format != KEY_FORMAT_CURRENT);
326
327 *w = 0;
328
329#define x(id, field) if (!set_inc_field(&state, id, in->field)) return false;
330 bkey_fields()
331#undef x
332 pack_state_finish(&state, out);
333 out->u64s = format->key_u64s + in->u64s - BKEY_U64s;
334 out->format = KEY_FORMAT_LOCAL_BTREE;
335 out->needs_whiteout = in->needs_whiteout;
336 out->type = in->type;
337
338 bch2_bkey_pack_verify(out, in, format);
339 return true;
340}
341
342/**
343 * bch2_bkey_unpack -- unpack the key and the value
344 * @b: btree node of @src key (for packed format)
345 * @dst: unpacked result
346 * @src: packed input
347 */
348void bch2_bkey_unpack(const struct btree *b, struct bkey_i *dst,
349 const struct bkey_packed *src)
350{
351 __bkey_unpack_key(b, &dst->k, src);
352
353 memcpy_u64s(&dst->v,
354 bkeyp_val(&b->format, src),
355 bkeyp_val_u64s(&b->format, src));
356}
357
358/**
359 * bch2_bkey_pack -- pack the key and the value
360 * @dst: packed result
361 * @src: unpacked input
362 * @format: format of packed result
363 *
364 * Returns: true on success, false on failure
365 */
366bool bch2_bkey_pack(struct bkey_packed *dst, const struct bkey_i *src,
367 const struct bkey_format *format)
368{
369 struct bkey_packed tmp;
370
371 if (!bch2_bkey_pack_key(&tmp, &src->k, format))
372 return false;
373
374 memmove_u64s((u64 *) dst + format->key_u64s,
375 &src->v,
376 bkey_val_u64s(&src->k));
377 memcpy_u64s_small(dst, &tmp, format->key_u64s);
378
379 return true;
380}
381
382__always_inline
383static bool set_inc_field_lossy(struct pack_state *state, unsigned field, u64 v)
384{
385 unsigned bits = state->format->bits_per_field[field];
386 u64 offset = le64_to_cpu(state->format->field_offset[field]);
387 bool ret = true;
388
389 EBUG_ON(v < offset);
390 v -= offset;
391
392 if (fls64(v) > bits) {
393 v = ~(~0ULL << bits);
394 ret = false;
395 }
396
397 __set_inc_field(state, field, v);
398 return ret;
399}
400
401#ifdef CONFIG_BCACHEFS_DEBUG
402static bool bkey_packed_successor(struct bkey_packed *out,
403 const struct btree *b,
404 struct bkey_packed k)
405{
406 const struct bkey_format *f = &b->format;
407 unsigned nr_key_bits = b->nr_key_bits;
408 unsigned first_bit, offset;
409 u64 *p;
410
411 EBUG_ON(b->nr_key_bits != bkey_format_key_bits(f));
412
413 if (!nr_key_bits)
414 return false;
415
416 *out = k;
417
418 first_bit = high_bit_offset + nr_key_bits - 1;
419 p = nth_word(high_word(f, out), first_bit >> 6);
420 offset = 63 - (first_bit & 63);
421
422 while (nr_key_bits) {
423 unsigned bits = min(64 - offset, nr_key_bits);
424 u64 mask = (~0ULL >> (64 - bits)) << offset;
425
426 if ((*p & mask) != mask) {
427 *p += 1ULL << offset;
428 EBUG_ON(bch2_bkey_cmp_packed(b, out, &k) <= 0);
429 return true;
430 }
431
432 *p &= ~mask;
433 p = prev_word(p);
434 nr_key_bits -= bits;
435 offset = 0;
436 }
437
438 return false;
439}
440
441static bool bkey_format_has_too_big_fields(const struct bkey_format *f)
442{
443 for (unsigned i = 0; i < f->nr_fields; i++) {
444 unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
445 u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
446 u64 packed_max = f->bits_per_field[i]
447 ? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
448 : 0;
449 u64 field_offset = le64_to_cpu(f->field_offset[i]);
450
451 if (packed_max + field_offset < packed_max ||
452 packed_max + field_offset > unpacked_max)
453 return true;
454 }
455
456 return false;
457}
458#endif
459
460/*
461 * Returns a packed key that compares <= in
462 *
463 * This is used in bset_search_tree(), where we need a packed pos in order to be
464 * able to compare against the keys in the auxiliary search tree - and it's
465 * legal to use a packed pos that isn't equivalent to the original pos,
466 * _provided_ it compares <= to the original pos.
467 */
468enum bkey_pack_pos_ret bch2_bkey_pack_pos_lossy(struct bkey_packed *out,
469 struct bpos in,
470 const struct btree *b)
471{
472 const struct bkey_format *f = &b->format;
473 struct pack_state state = pack_state_init(f, out);
474 u64 *w = out->_data;
475#ifdef CONFIG_BCACHEFS_DEBUG
476 struct bpos orig = in;
477#endif
478 bool exact = true;
479 unsigned i;
480
481 /*
482 * bch2_bkey_pack_key() will write to all of f->key_u64s, minus the 3
483 * byte header, but pack_pos() won't if the len/version fields are big
484 * enough - we need to make sure to zero them out:
485 */
486 for (i = 0; i < f->key_u64s; i++)
487 w[i] = 0;
488
489 if (unlikely(in.snapshot <
490 le64_to_cpu(f->field_offset[BKEY_FIELD_SNAPSHOT]))) {
491 if (!in.offset-- &&
492 !in.inode--)
493 return BKEY_PACK_POS_FAIL;
494 in.snapshot = KEY_SNAPSHOT_MAX;
495 exact = false;
496 }
497
498 if (unlikely(in.offset <
499 le64_to_cpu(f->field_offset[BKEY_FIELD_OFFSET]))) {
500 if (!in.inode--)
501 return BKEY_PACK_POS_FAIL;
502 in.offset = KEY_OFFSET_MAX;
503 in.snapshot = KEY_SNAPSHOT_MAX;
504 exact = false;
505 }
506
507 if (unlikely(in.inode <
508 le64_to_cpu(f->field_offset[BKEY_FIELD_INODE])))
509 return BKEY_PACK_POS_FAIL;
510
511 if (unlikely(!set_inc_field_lossy(&state, BKEY_FIELD_INODE, in.inode))) {
512 in.offset = KEY_OFFSET_MAX;
513 in.snapshot = KEY_SNAPSHOT_MAX;
514 exact = false;
515 }
516
517 if (unlikely(!set_inc_field_lossy(&state, BKEY_FIELD_OFFSET, in.offset))) {
518 in.snapshot = KEY_SNAPSHOT_MAX;
519 exact = false;
520 }
521
522 if (unlikely(!set_inc_field_lossy(&state, BKEY_FIELD_SNAPSHOT, in.snapshot)))
523 exact = false;
524
525 pack_state_finish(&state, out);
526 out->u64s = f->key_u64s;
527 out->format = KEY_FORMAT_LOCAL_BTREE;
528 out->type = KEY_TYPE_deleted;
529
530#ifdef CONFIG_BCACHEFS_DEBUG
531 if (exact) {
532 BUG_ON(bkey_cmp_left_packed(b, out, &orig));
533 } else {
534 struct bkey_packed successor;
535
536 BUG_ON(bkey_cmp_left_packed(b, out, &orig) >= 0);
537 BUG_ON(bkey_packed_successor(&successor, b, *out) &&
538 bkey_cmp_left_packed(b, &successor, &orig) < 0 &&
539 !bkey_format_has_too_big_fields(f));
540 }
541#endif
542
543 return exact ? BKEY_PACK_POS_EXACT : BKEY_PACK_POS_SMALLER;
544}
545
546void bch2_bkey_format_init(struct bkey_format_state *s)
547{
548 unsigned i;
549
550 for (i = 0; i < ARRAY_SIZE(s->field_min); i++)
551 s->field_min[i] = U64_MAX;
552
553 for (i = 0; i < ARRAY_SIZE(s->field_max); i++)
554 s->field_max[i] = 0;
555
556 /* Make sure we can store a size of 0: */
557 s->field_min[BKEY_FIELD_SIZE] = 0;
558}
559
560void bch2_bkey_format_add_pos(struct bkey_format_state *s, struct bpos p)
561{
562 unsigned field = 0;
563
564 __bkey_format_add(s, field++, p.inode);
565 __bkey_format_add(s, field++, p.offset);
566 __bkey_format_add(s, field++, p.snapshot);
567}
568
569/*
570 * We don't want it to be possible for the packed format to represent fields
571 * bigger than a u64... that will cause confusion and issues (like with
572 * bkey_packed_successor())
573 */
574static void set_format_field(struct bkey_format *f, enum bch_bkey_fields i,
575 unsigned bits, u64 offset)
576{
577 unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
578 u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
579
580 bits = min(bits, unpacked_bits);
581
582 offset = bits == unpacked_bits ? 0 : min(offset, unpacked_max - ((1ULL << bits) - 1));
583
584 f->bits_per_field[i] = bits;
585 f->field_offset[i] = cpu_to_le64(offset);
586}
587
588struct bkey_format bch2_bkey_format_done(struct bkey_format_state *s)
589{
590 unsigned i, bits = KEY_PACKED_BITS_START;
591 struct bkey_format ret = {
592 .nr_fields = BKEY_NR_FIELDS,
593 };
594
595 for (i = 0; i < ARRAY_SIZE(s->field_min); i++) {
596 s->field_min[i] = min(s->field_min[i], s->field_max[i]);
597
598 set_format_field(&ret, i,
599 fls64(s->field_max[i] - s->field_min[i]),
600 s->field_min[i]);
601
602 bits += ret.bits_per_field[i];
603 }
604
605 /* allow for extent merging: */
606 if (ret.bits_per_field[BKEY_FIELD_SIZE]) {
607 unsigned b = min(4U, 32U - ret.bits_per_field[BKEY_FIELD_SIZE]);
608
609 ret.bits_per_field[BKEY_FIELD_SIZE] += b;
610 bits += b;
611 }
612
613 ret.key_u64s = DIV_ROUND_UP(bits, 64);
614
615 /* if we have enough spare bits, round fields up to nearest byte */
616 bits = ret.key_u64s * 64 - bits;
617
618 for (i = 0; i < ARRAY_SIZE(ret.bits_per_field); i++) {
619 unsigned r = round_up(ret.bits_per_field[i], 8) -
620 ret.bits_per_field[i];
621
622 if (r <= bits) {
623 set_format_field(&ret, i,
624 ret.bits_per_field[i] + r,
625 le64_to_cpu(ret.field_offset[i]));
626 bits -= r;
627 }
628 }
629
630#ifdef CONFIG_BCACHEFS_DEBUG
631 {
632 struct printbuf buf = PRINTBUF;
633
634 BUG_ON(bch2_bkey_format_invalid(NULL, &ret, 0, &buf));
635 printbuf_exit(&buf);
636 }
637#endif
638 return ret;
639}
640
641int bch2_bkey_format_invalid(struct bch_fs *c,
642 struct bkey_format *f,
643 enum bkey_invalid_flags flags,
644 struct printbuf *err)
645{
646 unsigned i, bits = KEY_PACKED_BITS_START;
647
648 if (f->nr_fields != BKEY_NR_FIELDS) {
649 prt_printf(err, "incorrect number of fields: got %u, should be %u",
650 f->nr_fields, BKEY_NR_FIELDS);
651 return -BCH_ERR_invalid;
652 }
653
654 /*
655 * Verify that the packed format can't represent fields larger than the
656 * unpacked format:
657 */
658 for (i = 0; i < f->nr_fields; i++) {
659 if (!c || c->sb.version_min >= bcachefs_metadata_version_snapshot) {
660 unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
661 u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
662 u64 packed_max = f->bits_per_field[i]
663 ? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
664 : 0;
665 u64 field_offset = le64_to_cpu(f->field_offset[i]);
666
667 if (packed_max + field_offset < packed_max ||
668 packed_max + field_offset > unpacked_max) {
669 prt_printf(err, "field %u too large: %llu + %llu > %llu",
670 i, packed_max, field_offset, unpacked_max);
671 return -BCH_ERR_invalid;
672 }
673 }
674
675 bits += f->bits_per_field[i];
676 }
677
678 if (f->key_u64s != DIV_ROUND_UP(bits, 64)) {
679 prt_printf(err, "incorrect key_u64s: got %u, should be %u",
680 f->key_u64s, DIV_ROUND_UP(bits, 64));
681 return -BCH_ERR_invalid;
682 }
683
684 return 0;
685}
686
687void bch2_bkey_format_to_text(struct printbuf *out, const struct bkey_format *f)
688{
689 prt_printf(out, "u64s %u fields ", f->key_u64s);
690
691 for (unsigned i = 0; i < ARRAY_SIZE(f->bits_per_field); i++) {
692 if (i)
693 prt_str(out, ", ");
694 prt_printf(out, "%u:%llu",
695 f->bits_per_field[i],
696 le64_to_cpu(f->field_offset[i]));
697 }
698}
699
700/*
701 * Most significant differing bit
702 * Bits are indexed from 0 - return is [0, nr_key_bits)
703 */
704__pure
705unsigned bch2_bkey_greatest_differing_bit(const struct btree *b,
706 const struct bkey_packed *l_k,
707 const struct bkey_packed *r_k)
708{
709 const u64 *l = high_word(&b->format, l_k);
710 const u64 *r = high_word(&b->format, r_k);
711 unsigned nr_key_bits = b->nr_key_bits;
712 unsigned word_bits = 64 - high_bit_offset;
713 u64 l_v, r_v;
714
715 EBUG_ON(b->nr_key_bits != bkey_format_key_bits(&b->format));
716
717 /* for big endian, skip past header */
718 l_v = *l & (~0ULL >> high_bit_offset);
719 r_v = *r & (~0ULL >> high_bit_offset);
720
721 while (nr_key_bits) {
722 if (nr_key_bits < word_bits) {
723 l_v >>= word_bits - nr_key_bits;
724 r_v >>= word_bits - nr_key_bits;
725 nr_key_bits = 0;
726 } else {
727 nr_key_bits -= word_bits;
728 }
729
730 if (l_v != r_v)
731 return fls64(l_v ^ r_v) - 1 + nr_key_bits;
732
733 l = next_word(l);
734 r = next_word(r);
735
736 l_v = *l;
737 r_v = *r;
738 word_bits = 64;
739 }
740
741 return 0;
742}
743
744/*
745 * First set bit
746 * Bits are indexed from 0 - return is [0, nr_key_bits)
747 */
748__pure
749unsigned bch2_bkey_ffs(const struct btree *b, const struct bkey_packed *k)
750{
751 const u64 *p = high_word(&b->format, k);
752 unsigned nr_key_bits = b->nr_key_bits;
753 unsigned ret = 0, offset;
754
755 EBUG_ON(b->nr_key_bits != bkey_format_key_bits(&b->format));
756
757 offset = nr_key_bits;
758 while (offset > 64) {
759 p = next_word(p);
760 offset -= 64;
761 }
762
763 offset = 64 - offset;
764
765 while (nr_key_bits) {
766 unsigned bits = nr_key_bits + offset < 64
767 ? nr_key_bits
768 : 64 - offset;
769
770 u64 mask = (~0ULL >> (64 - bits)) << offset;
771
772 if (*p & mask)
773 return ret + __ffs64(*p & mask) - offset;
774
775 p = prev_word(p);
776 nr_key_bits -= bits;
777 ret += bits;
778 offset = 0;
779 }
780
781 return 0;
782}
783
784#ifdef HAVE_BCACHEFS_COMPILED_UNPACK
785
786#define I(_x) (*(out)++ = (_x))
787#define I1(i0) I(i0)
788#define I2(i0, i1) (I1(i0), I(i1))
789#define I3(i0, i1, i2) (I2(i0, i1), I(i2))
790#define I4(i0, i1, i2, i3) (I3(i0, i1, i2), I(i3))
791#define I5(i0, i1, i2, i3, i4) (I4(i0, i1, i2, i3), I(i4))
792
793static u8 *compile_bkey_field(const struct bkey_format *format, u8 *out,
794 enum bch_bkey_fields field,
795 unsigned dst_offset, unsigned dst_size,
796 bool *eax_zeroed)
797{
798 unsigned bits = format->bits_per_field[field];
799 u64 offset = le64_to_cpu(format->field_offset[field]);
800 unsigned i, byte, bit_offset, align, shl, shr;
801
802 if (!bits && !offset) {
803 if (!*eax_zeroed) {
804 /* xor eax, eax */
805 I2(0x31, 0xc0);
806 }
807
808 *eax_zeroed = true;
809 goto set_field;
810 }
811
812 if (!bits) {
813 /* just return offset: */
814
815 switch (dst_size) {
816 case 8:
817 if (offset > S32_MAX) {
818 /* mov [rdi + dst_offset], offset */
819 I3(0xc7, 0x47, dst_offset);
820 memcpy(out, &offset, 4);
821 out += 4;
822
823 I3(0xc7, 0x47, dst_offset + 4);
824 memcpy(out, (void *) &offset + 4, 4);
825 out += 4;
826 } else {
827 /* mov [rdi + dst_offset], offset */
828 /* sign extended */
829 I4(0x48, 0xc7, 0x47, dst_offset);
830 memcpy(out, &offset, 4);
831 out += 4;
832 }
833 break;
834 case 4:
835 /* mov [rdi + dst_offset], offset */
836 I3(0xc7, 0x47, dst_offset);
837 memcpy(out, &offset, 4);
838 out += 4;
839 break;
840 default:
841 BUG();
842 }
843
844 return out;
845 }
846
847 bit_offset = format->key_u64s * 64;
848 for (i = 0; i <= field; i++)
849 bit_offset -= format->bits_per_field[i];
850
851 byte = bit_offset / 8;
852 bit_offset -= byte * 8;
853
854 *eax_zeroed = false;
855
856 if (bit_offset == 0 && bits == 8) {
857 /* movzx eax, BYTE PTR [rsi + imm8] */
858 I4(0x0f, 0xb6, 0x46, byte);
859 } else if (bit_offset == 0 && bits == 16) {
860 /* movzx eax, WORD PTR [rsi + imm8] */
861 I4(0x0f, 0xb7, 0x46, byte);
862 } else if (bit_offset + bits <= 32) {
863 align = min(4 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 3);
864 byte -= align;
865 bit_offset += align * 8;
866
867 BUG_ON(bit_offset + bits > 32);
868
869 /* mov eax, [rsi + imm8] */
870 I3(0x8b, 0x46, byte);
871
872 if (bit_offset) {
873 /* shr eax, imm8 */
874 I3(0xc1, 0xe8, bit_offset);
875 }
876
877 if (bit_offset + bits < 32) {
878 unsigned mask = ~0U >> (32 - bits);
879
880 /* and eax, imm32 */
881 I1(0x25);
882 memcpy(out, &mask, 4);
883 out += 4;
884 }
885 } else if (bit_offset + bits <= 64) {
886 align = min(8 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 7);
887 byte -= align;
888 bit_offset += align * 8;
889
890 BUG_ON(bit_offset + bits > 64);
891
892 /* mov rax, [rsi + imm8] */
893 I4(0x48, 0x8b, 0x46, byte);
894
895 shl = 64 - bit_offset - bits;
896 shr = bit_offset + shl;
897
898 if (shl) {
899 /* shl rax, imm8 */
900 I4(0x48, 0xc1, 0xe0, shl);
901 }
902
903 if (shr) {
904 /* shr rax, imm8 */
905 I4(0x48, 0xc1, 0xe8, shr);
906 }
907 } else {
908 align = min(4 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 3);
909 byte -= align;
910 bit_offset += align * 8;
911
912 BUG_ON(bit_offset + bits > 96);
913
914 /* mov rax, [rsi + byte] */
915 I4(0x48, 0x8b, 0x46, byte);
916
917 /* mov edx, [rsi + byte + 8] */
918 I3(0x8b, 0x56, byte + 8);
919
920 /* bits from next word: */
921 shr = bit_offset + bits - 64;
922 BUG_ON(shr > bit_offset);
923
924 /* shr rax, bit_offset */
925 I4(0x48, 0xc1, 0xe8, shr);
926
927 /* shl rdx, imm8 */
928 I4(0x48, 0xc1, 0xe2, 64 - shr);
929
930 /* or rax, rdx */
931 I3(0x48, 0x09, 0xd0);
932
933 shr = bit_offset - shr;
934
935 if (shr) {
936 /* shr rax, imm8 */
937 I4(0x48, 0xc1, 0xe8, shr);
938 }
939 }
940
941 /* rax += offset: */
942 if (offset > S32_MAX) {
943 /* mov rdx, imm64 */
944 I2(0x48, 0xba);
945 memcpy(out, &offset, 8);
946 out += 8;
947 /* add %rdx, %rax */
948 I3(0x48, 0x01, 0xd0);
949 } else if (offset + (~0ULL >> (64 - bits)) > U32_MAX) {
950 /* add rax, imm32 */
951 I2(0x48, 0x05);
952 memcpy(out, &offset, 4);
953 out += 4;
954 } else if (offset) {
955 /* add eax, imm32 */
956 I1(0x05);
957 memcpy(out, &offset, 4);
958 out += 4;
959 }
960set_field:
961 switch (dst_size) {
962 case 8:
963 /* mov [rdi + dst_offset], rax */
964 I4(0x48, 0x89, 0x47, dst_offset);
965 break;
966 case 4:
967 /* mov [rdi + dst_offset], eax */
968 I3(0x89, 0x47, dst_offset);
969 break;
970 default:
971 BUG();
972 }
973
974 return out;
975}
976
977int bch2_compile_bkey_format(const struct bkey_format *format, void *_out)
978{
979 bool eax_zeroed = false;
980 u8 *out = _out;
981
982 /*
983 * rdi: dst - unpacked key
984 * rsi: src - packed key
985 */
986
987 /* k->u64s, k->format, k->type */
988
989 /* mov eax, [rsi] */
990 I2(0x8b, 0x06);
991
992 /* add eax, BKEY_U64s - format->key_u64s */
993 I5(0x05, BKEY_U64s - format->key_u64s, KEY_FORMAT_CURRENT, 0, 0);
994
995 /* and eax, imm32: mask out k->pad: */
996 I5(0x25, 0xff, 0xff, 0xff, 0);
997
998 /* mov [rdi], eax */
999 I2(0x89, 0x07);
1000
1001#define x(id, field) \
1002 out = compile_bkey_field(format, out, id, \
1003 offsetof(struct bkey, field), \
1004 sizeof(((struct bkey *) NULL)->field), \
1005 &eax_zeroed);
1006 bkey_fields()
1007#undef x
1008
1009 /* retq */
1010 I1(0xc3);
1011
1012 return (void *) out - _out;
1013}
1014
1015#else
1016#endif
1017
1018__pure
1019int __bch2_bkey_cmp_packed_format_checked(const struct bkey_packed *l,
1020 const struct bkey_packed *r,
1021 const struct btree *b)
1022{
1023 return __bch2_bkey_cmp_packed_format_checked_inlined(l, r, b);
1024}
1025
1026__pure __flatten
1027int __bch2_bkey_cmp_left_packed_format_checked(const struct btree *b,
1028 const struct bkey_packed *l,
1029 const struct bpos *r)
1030{
1031 return bpos_cmp(bkey_unpack_pos_format_checked(b, l), *r);
1032}
1033
1034__pure __flatten
1035int bch2_bkey_cmp_packed(const struct btree *b,
1036 const struct bkey_packed *l,
1037 const struct bkey_packed *r)
1038{
1039 return bch2_bkey_cmp_packed_inlined(b, l, r);
1040}
1041
1042__pure __flatten
1043int __bch2_bkey_cmp_left_packed(const struct btree *b,
1044 const struct bkey_packed *l,
1045 const struct bpos *r)
1046{
1047 const struct bkey *l_unpacked;
1048
1049 return unlikely(l_unpacked = packed_to_bkey_c(l))
1050 ? bpos_cmp(l_unpacked->p, *r)
1051 : __bch2_bkey_cmp_left_packed_format_checked(b, l, r);
1052}
1053
1054void bch2_bpos_swab(struct bpos *p)
1055{
1056 u8 *l = (u8 *) p;
1057 u8 *h = ((u8 *) &p[1]) - 1;
1058
1059 while (l < h) {
1060 swap(*l, *h);
1061 l++;
1062 --h;
1063 }
1064}
1065
1066void bch2_bkey_swab_key(const struct bkey_format *_f, struct bkey_packed *k)
1067{
1068 const struct bkey_format *f = bkey_packed(k) ? _f : &bch2_bkey_format_current;
1069 u8 *l = k->key_start;
1070 u8 *h = (u8 *) (k->_data + f->key_u64s) - 1;
1071
1072 while (l < h) {
1073 swap(*l, *h);
1074 l++;
1075 --h;
1076 }
1077}
1078
1079#ifdef CONFIG_BCACHEFS_DEBUG
1080void bch2_bkey_pack_test(void)
1081{
1082 struct bkey t = KEY(4134ULL, 1250629070527416633ULL, 0);
1083 struct bkey_packed p;
1084
1085 struct bkey_format test_format = {
1086 .key_u64s = 3,
1087 .nr_fields = BKEY_NR_FIELDS,
1088 .bits_per_field = {
1089 13,
1090 64,
1091 32,
1092 },
1093 };
1094
1095 struct unpack_state in_s =
1096 unpack_state_init(&bch2_bkey_format_current, (void *) &t);
1097 struct pack_state out_s = pack_state_init(&test_format, &p);
1098 unsigned i;
1099
1100 for (i = 0; i < out_s.format->nr_fields; i++) {
1101 u64 a, v = get_inc_field(&in_s, i);
1102
1103 switch (i) {
1104#define x(id, field) case id: a = t.field; break;
1105 bkey_fields()
1106#undef x
1107 default:
1108 BUG();
1109 }
1110
1111 if (a != v)
1112 panic("got %llu actual %llu i %u\n", v, a, i);
1113
1114 if (!set_inc_field(&out_s, i, v))
1115 panic("failed at %u\n", i);
1116 }
1117
1118 BUG_ON(!bch2_bkey_pack_key(&p, &t, &test_format));
1119}
1120#endif