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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Code for working with individual keys, and sorted sets of keys with in a
4 * btree node
5 *
6 * Copyright 2012 Google, Inc.
7 */
8
9#define pr_fmt(fmt) "bcache: %s() " fmt, __func__
10
11#include "util.h"
12#include "bset.h"
13
14#include <linux/console.h>
15#include <linux/sched/clock.h>
16#include <linux/random.h>
17#include <linux/prefetch.h>
18
19#ifdef CONFIG_BCACHE_DEBUG
20
21void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned int set)
22{
23 struct bkey *k, *next;
24
25 for (k = i->start; k < bset_bkey_last(i); k = next) {
26 next = bkey_next(k);
27
28 pr_err("block %u key %u/%u: ", set,
29 (unsigned int) ((u64 *) k - i->d), i->keys);
30
31 if (b->ops->key_dump)
32 b->ops->key_dump(b, k);
33 else
34 pr_cont("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k));
35
36 if (next < bset_bkey_last(i) &&
37 bkey_cmp(k, b->ops->is_extents ?
38 &START_KEY(next) : next) > 0)
39 pr_err("Key skipped backwards\n");
40 }
41}
42
43void bch_dump_bucket(struct btree_keys *b)
44{
45 unsigned int i;
46
47 console_lock();
48 for (i = 0; i <= b->nsets; i++)
49 bch_dump_bset(b, b->set[i].data,
50 bset_sector_offset(b, b->set[i].data));
51 console_unlock();
52}
53
54int __bch_count_data(struct btree_keys *b)
55{
56 unsigned int ret = 0;
57 struct btree_iter iter;
58 struct bkey *k;
59
60 if (b->ops->is_extents)
61 for_each_key(b, k, &iter)
62 ret += KEY_SIZE(k);
63 return ret;
64}
65
66void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
67{
68 va_list args;
69 struct bkey *k, *p = NULL;
70 struct btree_iter iter;
71 const char *err;
72
73 for_each_key(b, k, &iter) {
74 if (b->ops->is_extents) {
75 err = "Keys out of order";
76 if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
77 goto bug;
78
79 if (bch_ptr_invalid(b, k))
80 continue;
81
82 err = "Overlapping keys";
83 if (p && bkey_cmp(p, &START_KEY(k)) > 0)
84 goto bug;
85 } else {
86 if (bch_ptr_bad(b, k))
87 continue;
88
89 err = "Duplicate keys";
90 if (p && !bkey_cmp(p, k))
91 goto bug;
92 }
93 p = k;
94 }
95#if 0
96 err = "Key larger than btree node key";
97 if (p && bkey_cmp(p, &b->key) > 0)
98 goto bug;
99#endif
100 return;
101bug:
102 bch_dump_bucket(b);
103
104 va_start(args, fmt);
105 vprintk(fmt, args);
106 va_end(args);
107
108 panic("bch_check_keys error: %s:\n", err);
109}
110
111static void bch_btree_iter_next_check(struct btree_iter *iter)
112{
113 struct bkey *k = iter->data->k, *next = bkey_next(k);
114
115 if (next < iter->data->end &&
116 bkey_cmp(k, iter->b->ops->is_extents ?
117 &START_KEY(next) : next) > 0) {
118 bch_dump_bucket(iter->b);
119 panic("Key skipped backwards\n");
120 }
121}
122
123#else
124
125static inline void bch_btree_iter_next_check(struct btree_iter *iter) {}
126
127#endif
128
129/* Keylists */
130
131int __bch_keylist_realloc(struct keylist *l, unsigned int u64s)
132{
133 size_t oldsize = bch_keylist_nkeys(l);
134 size_t newsize = oldsize + u64s;
135 uint64_t *old_keys = l->keys_p == l->inline_keys ? NULL : l->keys_p;
136 uint64_t *new_keys;
137
138 newsize = roundup_pow_of_two(newsize);
139
140 if (newsize <= KEYLIST_INLINE ||
141 roundup_pow_of_two(oldsize) == newsize)
142 return 0;
143
144 new_keys = krealloc(old_keys, sizeof(uint64_t) * newsize, GFP_NOIO);
145
146 if (!new_keys)
147 return -ENOMEM;
148
149 if (!old_keys)
150 memcpy(new_keys, l->inline_keys, sizeof(uint64_t) * oldsize);
151
152 l->keys_p = new_keys;
153 l->top_p = new_keys + oldsize;
154
155 return 0;
156}
157
158/* Pop the top key of keylist by pointing l->top to its previous key */
159struct bkey *bch_keylist_pop(struct keylist *l)
160{
161 struct bkey *k = l->keys;
162
163 if (k == l->top)
164 return NULL;
165
166 while (bkey_next(k) != l->top)
167 k = bkey_next(k);
168
169 return l->top = k;
170}
171
172/* Pop the bottom key of keylist and update l->top_p */
173void bch_keylist_pop_front(struct keylist *l)
174{
175 l->top_p -= bkey_u64s(l->keys);
176
177 memmove(l->keys,
178 bkey_next(l->keys),
179 bch_keylist_bytes(l));
180}
181
182/* Key/pointer manipulation */
183
184void bch_bkey_copy_single_ptr(struct bkey *dest, const struct bkey *src,
185 unsigned int i)
186{
187 BUG_ON(i > KEY_PTRS(src));
188
189 /* Only copy the header, key, and one pointer. */
190 memcpy(dest, src, 2 * sizeof(uint64_t));
191 dest->ptr[0] = src->ptr[i];
192 SET_KEY_PTRS(dest, 1);
193 /* We didn't copy the checksum so clear that bit. */
194 SET_KEY_CSUM(dest, 0);
195}
196
197bool __bch_cut_front(const struct bkey *where, struct bkey *k)
198{
199 unsigned int i, len = 0;
200
201 if (bkey_cmp(where, &START_KEY(k)) <= 0)
202 return false;
203
204 if (bkey_cmp(where, k) < 0)
205 len = KEY_OFFSET(k) - KEY_OFFSET(where);
206 else
207 bkey_copy_key(k, where);
208
209 for (i = 0; i < KEY_PTRS(k); i++)
210 SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + KEY_SIZE(k) - len);
211
212 BUG_ON(len > KEY_SIZE(k));
213 SET_KEY_SIZE(k, len);
214 return true;
215}
216
217bool __bch_cut_back(const struct bkey *where, struct bkey *k)
218{
219 unsigned int len = 0;
220
221 if (bkey_cmp(where, k) >= 0)
222 return false;
223
224 BUG_ON(KEY_INODE(where) != KEY_INODE(k));
225
226 if (bkey_cmp(where, &START_KEY(k)) > 0)
227 len = KEY_OFFSET(where) - KEY_START(k);
228
229 bkey_copy_key(k, where);
230
231 BUG_ON(len > KEY_SIZE(k));
232 SET_KEY_SIZE(k, len);
233 return true;
234}
235
236/* Auxiliary search trees */
237
238/* 32 bits total: */
239#define BKEY_MID_BITS 3
240#define BKEY_EXPONENT_BITS 7
241#define BKEY_MANTISSA_BITS (32 - BKEY_MID_BITS - BKEY_EXPONENT_BITS)
242#define BKEY_MANTISSA_MASK ((1 << BKEY_MANTISSA_BITS) - 1)
243
244struct bkey_float {
245 unsigned int exponent:BKEY_EXPONENT_BITS;
246 unsigned int m:BKEY_MID_BITS;
247 unsigned int mantissa:BKEY_MANTISSA_BITS;
248} __packed;
249
250/*
251 * BSET_CACHELINE was originally intended to match the hardware cacheline size -
252 * it used to be 64, but I realized the lookup code would touch slightly less
253 * memory if it was 128.
254 *
255 * It definites the number of bytes (in struct bset) per struct bkey_float in
256 * the auxiliar search tree - when we're done searching the bset_float tree we
257 * have this many bytes left that we do a linear search over.
258 *
259 * Since (after level 5) every level of the bset_tree is on a new cacheline,
260 * we're touching one fewer cacheline in the bset tree in exchange for one more
261 * cacheline in the linear search - but the linear search might stop before it
262 * gets to the second cacheline.
263 */
264
265#define BSET_CACHELINE 128
266
267/* Space required for the btree node keys */
268static inline size_t btree_keys_bytes(struct btree_keys *b)
269{
270 return PAGE_SIZE << b->page_order;
271}
272
273static inline size_t btree_keys_cachelines(struct btree_keys *b)
274{
275 return btree_keys_bytes(b) / BSET_CACHELINE;
276}
277
278/* Space required for the auxiliary search trees */
279static inline size_t bset_tree_bytes(struct btree_keys *b)
280{
281 return btree_keys_cachelines(b) * sizeof(struct bkey_float);
282}
283
284/* Space required for the prev pointers */
285static inline size_t bset_prev_bytes(struct btree_keys *b)
286{
287 return btree_keys_cachelines(b) * sizeof(uint8_t);
288}
289
290/* Memory allocation */
291
292void bch_btree_keys_free(struct btree_keys *b)
293{
294 struct bset_tree *t = b->set;
295
296 if (bset_prev_bytes(b) < PAGE_SIZE)
297 kfree(t->prev);
298 else
299 free_pages((unsigned long) t->prev,
300 get_order(bset_prev_bytes(b)));
301
302 if (bset_tree_bytes(b) < PAGE_SIZE)
303 kfree(t->tree);
304 else
305 free_pages((unsigned long) t->tree,
306 get_order(bset_tree_bytes(b)));
307
308 free_pages((unsigned long) t->data, b->page_order);
309
310 t->prev = NULL;
311 t->tree = NULL;
312 t->data = NULL;
313}
314
315int bch_btree_keys_alloc(struct btree_keys *b,
316 unsigned int page_order,
317 gfp_t gfp)
318{
319 struct bset_tree *t = b->set;
320
321 BUG_ON(t->data);
322
323 b->page_order = page_order;
324
325 t->data = (void *) __get_free_pages(__GFP_COMP|gfp, b->page_order);
326 if (!t->data)
327 goto err;
328
329 t->tree = bset_tree_bytes(b) < PAGE_SIZE
330 ? kmalloc(bset_tree_bytes(b), gfp)
331 : (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b)));
332 if (!t->tree)
333 goto err;
334
335 t->prev = bset_prev_bytes(b) < PAGE_SIZE
336 ? kmalloc(bset_prev_bytes(b), gfp)
337 : (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b)));
338 if (!t->prev)
339 goto err;
340
341 return 0;
342err:
343 bch_btree_keys_free(b);
344 return -ENOMEM;
345}
346
347void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
348 bool *expensive_debug_checks)
349{
350 b->ops = ops;
351 b->expensive_debug_checks = expensive_debug_checks;
352 b->nsets = 0;
353 b->last_set_unwritten = 0;
354
355 /*
356 * struct btree_keys in embedded in struct btree, and struct
357 * bset_tree is embedded into struct btree_keys. They are all
358 * initialized as 0 by kzalloc() in mca_bucket_alloc(), and
359 * b->set[0].data is allocated in bch_btree_keys_alloc(), so we
360 * don't have to initiate b->set[].size and b->set[].data here
361 * any more.
362 */
363}
364
365/* Binary tree stuff for auxiliary search trees */
366
367/*
368 * return array index next to j when does in-order traverse
369 * of a binary tree which is stored in a linear array
370 */
371static unsigned int inorder_next(unsigned int j, unsigned int size)
372{
373 if (j * 2 + 1 < size) {
374 j = j * 2 + 1;
375
376 while (j * 2 < size)
377 j *= 2;
378 } else
379 j >>= ffz(j) + 1;
380
381 return j;
382}
383
384/*
385 * return array index previous to j when does in-order traverse
386 * of a binary tree which is stored in a linear array
387 */
388static unsigned int inorder_prev(unsigned int j, unsigned int size)
389{
390 if (j * 2 < size) {
391 j = j * 2;
392
393 while (j * 2 + 1 < size)
394 j = j * 2 + 1;
395 } else
396 j >>= ffs(j);
397
398 return j;
399}
400
401/*
402 * I have no idea why this code works... and I'm the one who wrote it
403 *
404 * However, I do know what it does:
405 * Given a binary tree constructed in an array (i.e. how you normally implement
406 * a heap), it converts a node in the tree - referenced by array index - to the
407 * index it would have if you did an inorder traversal.
408 *
409 * Also tested for every j, size up to size somewhere around 6 million.
410 *
411 * The binary tree starts at array index 1, not 0
412 * extra is a function of size:
413 * extra = (size - rounddown_pow_of_two(size - 1)) << 1;
414 */
415static unsigned int __to_inorder(unsigned int j,
416 unsigned int size,
417 unsigned int extra)
418{
419 unsigned int b = fls(j);
420 unsigned int shift = fls(size - 1) - b;
421
422 j ^= 1U << (b - 1);
423 j <<= 1;
424 j |= 1;
425 j <<= shift;
426
427 if (j > extra)
428 j -= (j - extra) >> 1;
429
430 return j;
431}
432
433/*
434 * Return the cacheline index in bset_tree->data, where j is index
435 * from a linear array which stores the auxiliar binary tree
436 */
437static unsigned int to_inorder(unsigned int j, struct bset_tree *t)
438{
439 return __to_inorder(j, t->size, t->extra);
440}
441
442static unsigned int __inorder_to_tree(unsigned int j,
443 unsigned int size,
444 unsigned int extra)
445{
446 unsigned int shift;
447
448 if (j > extra)
449 j += j - extra;
450
451 shift = ffs(j);
452
453 j >>= shift;
454 j |= roundup_pow_of_two(size) >> shift;
455
456 return j;
457}
458
459/*
460 * Return an index from a linear array which stores the auxiliar binary
461 * tree, j is the cacheline index of t->data.
462 */
463static unsigned int inorder_to_tree(unsigned int j, struct bset_tree *t)
464{
465 return __inorder_to_tree(j, t->size, t->extra);
466}
467
468#if 0
469void inorder_test(void)
470{
471 unsigned long done = 0;
472 ktime_t start = ktime_get();
473
474 for (unsigned int size = 2;
475 size < 65536000;
476 size++) {
477 unsigned int extra =
478 (size - rounddown_pow_of_two(size - 1)) << 1;
479 unsigned int i = 1, j = rounddown_pow_of_two(size - 1);
480
481 if (!(size % 4096))
482 pr_notice("loop %u, %llu per us\n", size,
483 done / ktime_us_delta(ktime_get(), start));
484
485 while (1) {
486 if (__inorder_to_tree(i, size, extra) != j)
487 panic("size %10u j %10u i %10u", size, j, i);
488
489 if (__to_inorder(j, size, extra) != i)
490 panic("size %10u j %10u i %10u", size, j, i);
491
492 if (j == rounddown_pow_of_two(size) - 1)
493 break;
494
495 BUG_ON(inorder_prev(inorder_next(j, size), size) != j);
496
497 j = inorder_next(j, size);
498 i++;
499 }
500
501 done += size - 1;
502 }
503}
504#endif
505
506/*
507 * Cacheline/offset <-> bkey pointer arithmetic:
508 *
509 * t->tree is a binary search tree in an array; each node corresponds to a key
510 * in one cacheline in t->set (BSET_CACHELINE bytes).
511 *
512 * This means we don't have to store the full index of the key that a node in
513 * the binary tree points to; to_inorder() gives us the cacheline, and then
514 * bkey_float->m gives us the offset within that cacheline, in units of 8 bytes.
515 *
516 * cacheline_to_bkey() and friends abstract out all the pointer arithmetic to
517 * make this work.
518 *
519 * To construct the bfloat for an arbitrary key we need to know what the key
520 * immediately preceding it is: we have to check if the two keys differ in the
521 * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size
522 * of the previous key so we can walk backwards to it from t->tree[j]'s key.
523 */
524
525static struct bkey *cacheline_to_bkey(struct bset_tree *t,
526 unsigned int cacheline,
527 unsigned int offset)
528{
529 return ((void *) t->data) + cacheline * BSET_CACHELINE + offset * 8;
530}
531
532static unsigned int bkey_to_cacheline(struct bset_tree *t, struct bkey *k)
533{
534 return ((void *) k - (void *) t->data) / BSET_CACHELINE;
535}
536
537static unsigned int bkey_to_cacheline_offset(struct bset_tree *t,
538 unsigned int cacheline,
539 struct bkey *k)
540{
541 return (u64 *) k - (u64 *) cacheline_to_bkey(t, cacheline, 0);
542}
543
544static struct bkey *tree_to_bkey(struct bset_tree *t, unsigned int j)
545{
546 return cacheline_to_bkey(t, to_inorder(j, t), t->tree[j].m);
547}
548
549static struct bkey *tree_to_prev_bkey(struct bset_tree *t, unsigned int j)
550{
551 return (void *) (((uint64_t *) tree_to_bkey(t, j)) - t->prev[j]);
552}
553
554/*
555 * For the write set - the one we're currently inserting keys into - we don't
556 * maintain a full search tree, we just keep a simple lookup table in t->prev.
557 */
558static struct bkey *table_to_bkey(struct bset_tree *t, unsigned int cacheline)
559{
560 return cacheline_to_bkey(t, cacheline, t->prev[cacheline]);
561}
562
563static inline uint64_t shrd128(uint64_t high, uint64_t low, uint8_t shift)
564{
565 low >>= shift;
566 low |= (high << 1) << (63U - shift);
567 return low;
568}
569
570/*
571 * Calculate mantissa value for struct bkey_float.
572 * If most significant bit of f->exponent is not set, then
573 * - f->exponent >> 6 is 0
574 * - p[0] points to bkey->low
575 * - p[-1] borrows bits from KEY_INODE() of bkey->high
576 * if most isgnificant bits of f->exponent is set, then
577 * - f->exponent >> 6 is 1
578 * - p[0] points to bits from KEY_INODE() of bkey->high
579 * - p[-1] points to other bits from KEY_INODE() of
580 * bkey->high too.
581 * See make_bfloat() to check when most significant bit of f->exponent
582 * is set or not.
583 */
584static inline unsigned int bfloat_mantissa(const struct bkey *k,
585 struct bkey_float *f)
586{
587 const uint64_t *p = &k->low - (f->exponent >> 6);
588
589 return shrd128(p[-1], p[0], f->exponent & 63) & BKEY_MANTISSA_MASK;
590}
591
592static void make_bfloat(struct bset_tree *t, unsigned int j)
593{
594 struct bkey_float *f = &t->tree[j];
595 struct bkey *m = tree_to_bkey(t, j);
596 struct bkey *p = tree_to_prev_bkey(t, j);
597
598 struct bkey *l = is_power_of_2(j)
599 ? t->data->start
600 : tree_to_prev_bkey(t, j >> ffs(j));
601
602 struct bkey *r = is_power_of_2(j + 1)
603 ? bset_bkey_idx(t->data, t->data->keys - bkey_u64s(&t->end))
604 : tree_to_bkey(t, j >> (ffz(j) + 1));
605
606 BUG_ON(m < l || m > r);
607 BUG_ON(bkey_next(p) != m);
608
609 /*
610 * If l and r have different KEY_INODE values (different backing
611 * device), f->exponent records how many least significant bits
612 * are different in KEY_INODE values and sets most significant
613 * bits to 1 (by +64).
614 * If l and r have same KEY_INODE value, f->exponent records
615 * how many different bits in least significant bits of bkey->low.
616 * See bfloat_mantiss() how the most significant bit of
617 * f->exponent is used to calculate bfloat mantissa value.
618 */
619 if (KEY_INODE(l) != KEY_INODE(r))
620 f->exponent = fls64(KEY_INODE(r) ^ KEY_INODE(l)) + 64;
621 else
622 f->exponent = fls64(r->low ^ l->low);
623
624 f->exponent = max_t(int, f->exponent - BKEY_MANTISSA_BITS, 0);
625
626 /*
627 * Setting f->exponent = 127 flags this node as failed, and causes the
628 * lookup code to fall back to comparing against the original key.
629 */
630
631 if (bfloat_mantissa(m, f) != bfloat_mantissa(p, f))
632 f->mantissa = bfloat_mantissa(m, f) - 1;
633 else
634 f->exponent = 127;
635}
636
637static void bset_alloc_tree(struct btree_keys *b, struct bset_tree *t)
638{
639 if (t != b->set) {
640 unsigned int j = roundup(t[-1].size,
641 64 / sizeof(struct bkey_float));
642
643 t->tree = t[-1].tree + j;
644 t->prev = t[-1].prev + j;
645 }
646
647 while (t < b->set + MAX_BSETS)
648 t++->size = 0;
649}
650
651static void bch_bset_build_unwritten_tree(struct btree_keys *b)
652{
653 struct bset_tree *t = bset_tree_last(b);
654
655 BUG_ON(b->last_set_unwritten);
656 b->last_set_unwritten = 1;
657
658 bset_alloc_tree(b, t);
659
660 if (t->tree != b->set->tree + btree_keys_cachelines(b)) {
661 t->prev[0] = bkey_to_cacheline_offset(t, 0, t->data->start);
662 t->size = 1;
663 }
664}
665
666void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
667{
668 if (i != b->set->data) {
669 b->set[++b->nsets].data = i;
670 i->seq = b->set->data->seq;
671 } else
672 get_random_bytes(&i->seq, sizeof(uint64_t));
673
674 i->magic = magic;
675 i->version = 0;
676 i->keys = 0;
677
678 bch_bset_build_unwritten_tree(b);
679}
680
681/*
682 * Build auxiliary binary tree 'struct bset_tree *t', this tree is used to
683 * accelerate bkey search in a btree node (pointed by bset_tree->data in
684 * memory). After search in the auxiliar tree by calling bset_search_tree(),
685 * a struct bset_search_iter is returned which indicates range [l, r] from
686 * bset_tree->data where the searching bkey might be inside. Then a followed
687 * linear comparison does the exact search, see __bch_bset_search() for how
688 * the auxiliary tree is used.
689 */
690void bch_bset_build_written_tree(struct btree_keys *b)
691{
692 struct bset_tree *t = bset_tree_last(b);
693 struct bkey *prev = NULL, *k = t->data->start;
694 unsigned int j, cacheline = 1;
695
696 b->last_set_unwritten = 0;
697
698 bset_alloc_tree(b, t);
699
700 t->size = min_t(unsigned int,
701 bkey_to_cacheline(t, bset_bkey_last(t->data)),
702 b->set->tree + btree_keys_cachelines(b) - t->tree);
703
704 if (t->size < 2) {
705 t->size = 0;
706 return;
707 }
708
709 t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1;
710
711 /* First we figure out where the first key in each cacheline is */
712 for (j = inorder_next(0, t->size);
713 j;
714 j = inorder_next(j, t->size)) {
715 while (bkey_to_cacheline(t, k) < cacheline) {
716 prev = k;
717 k = bkey_next(k);
718 }
719
720 t->prev[j] = bkey_u64s(prev);
721 t->tree[j].m = bkey_to_cacheline_offset(t, cacheline++, k);
722 }
723
724 while (bkey_next(k) != bset_bkey_last(t->data))
725 k = bkey_next(k);
726
727 t->end = *k;
728
729 /* Then we build the tree */
730 for (j = inorder_next(0, t->size);
731 j;
732 j = inorder_next(j, t->size))
733 make_bfloat(t, j);
734}
735
736/* Insert */
737
738void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k)
739{
740 struct bset_tree *t;
741 unsigned int inorder, j = 1;
742
743 for (t = b->set; t <= bset_tree_last(b); t++)
744 if (k < bset_bkey_last(t->data))
745 goto found_set;
746
747 BUG();
748found_set:
749 if (!t->size || !bset_written(b, t))
750 return;
751
752 inorder = bkey_to_cacheline(t, k);
753
754 if (k == t->data->start)
755 goto fix_left;
756
757 if (bkey_next(k) == bset_bkey_last(t->data)) {
758 t->end = *k;
759 goto fix_right;
760 }
761
762 j = inorder_to_tree(inorder, t);
763
764 if (j &&
765 j < t->size &&
766 k == tree_to_bkey(t, j))
767fix_left: do {
768 make_bfloat(t, j);
769 j = j * 2;
770 } while (j < t->size);
771
772 j = inorder_to_tree(inorder + 1, t);
773
774 if (j &&
775 j < t->size &&
776 k == tree_to_prev_bkey(t, j))
777fix_right: do {
778 make_bfloat(t, j);
779 j = j * 2 + 1;
780 } while (j < t->size);
781}
782
783static void bch_bset_fix_lookup_table(struct btree_keys *b,
784 struct bset_tree *t,
785 struct bkey *k)
786{
787 unsigned int shift = bkey_u64s(k);
788 unsigned int j = bkey_to_cacheline(t, k);
789
790 /* We're getting called from btree_split() or btree_gc, just bail out */
791 if (!t->size)
792 return;
793
794 /*
795 * k is the key we just inserted; we need to find the entry in the
796 * lookup table for the first key that is strictly greater than k:
797 * it's either k's cacheline or the next one
798 */
799 while (j < t->size &&
800 table_to_bkey(t, j) <= k)
801 j++;
802
803 /*
804 * Adjust all the lookup table entries, and find a new key for any that
805 * have gotten too big
806 */
807 for (; j < t->size; j++) {
808 t->prev[j] += shift;
809
810 if (t->prev[j] > 7) {
811 k = table_to_bkey(t, j - 1);
812
813 while (k < cacheline_to_bkey(t, j, 0))
814 k = bkey_next(k);
815
816 t->prev[j] = bkey_to_cacheline_offset(t, j, k);
817 }
818 }
819
820 if (t->size == b->set->tree + btree_keys_cachelines(b) - t->tree)
821 return;
822
823 /* Possibly add a new entry to the end of the lookup table */
824
825 for (k = table_to_bkey(t, t->size - 1);
826 k != bset_bkey_last(t->data);
827 k = bkey_next(k))
828 if (t->size == bkey_to_cacheline(t, k)) {
829 t->prev[t->size] =
830 bkey_to_cacheline_offset(t, t->size, k);
831 t->size++;
832 }
833}
834
835/*
836 * Tries to merge l and r: l should be lower than r
837 * Returns true if we were able to merge. If we did merge, l will be the merged
838 * key, r will be untouched.
839 */
840bool bch_bkey_try_merge(struct btree_keys *b, struct bkey *l, struct bkey *r)
841{
842 if (!b->ops->key_merge)
843 return false;
844
845 /*
846 * Generic header checks
847 * Assumes left and right are in order
848 * Left and right must be exactly aligned
849 */
850 if (!bch_bkey_equal_header(l, r) ||
851 bkey_cmp(l, &START_KEY(r)))
852 return false;
853
854 return b->ops->key_merge(b, l, r);
855}
856
857void bch_bset_insert(struct btree_keys *b, struct bkey *where,
858 struct bkey *insert)
859{
860 struct bset_tree *t = bset_tree_last(b);
861
862 BUG_ON(!b->last_set_unwritten);
863 BUG_ON(bset_byte_offset(b, t->data) +
864 __set_bytes(t->data, t->data->keys + bkey_u64s(insert)) >
865 PAGE_SIZE << b->page_order);
866
867 memmove((uint64_t *) where + bkey_u64s(insert),
868 where,
869 (void *) bset_bkey_last(t->data) - (void *) where);
870
871 t->data->keys += bkey_u64s(insert);
872 bkey_copy(where, insert);
873 bch_bset_fix_lookup_table(b, t, where);
874}
875
876unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
877 struct bkey *replace_key)
878{
879 unsigned int status = BTREE_INSERT_STATUS_NO_INSERT;
880 struct bset *i = bset_tree_last(b)->data;
881 struct bkey *m, *prev = NULL;
882 struct btree_iter iter;
883 struct bkey preceding_key_on_stack = ZERO_KEY;
884 struct bkey *preceding_key_p = &preceding_key_on_stack;
885
886 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
887
888 /*
889 * If k has preceding key, preceding_key_p will be set to address
890 * of k's preceding key; otherwise preceding_key_p will be set
891 * to NULL inside preceding_key().
892 */
893 if (b->ops->is_extents)
894 preceding_key(&START_KEY(k), &preceding_key_p);
895 else
896 preceding_key(k, &preceding_key_p);
897
898 m = bch_btree_iter_init(b, &iter, preceding_key_p);
899
900 if (b->ops->insert_fixup(b, k, &iter, replace_key))
901 return status;
902
903 status = BTREE_INSERT_STATUS_INSERT;
904
905 while (m != bset_bkey_last(i) &&
906 bkey_cmp(k, b->ops->is_extents ? &START_KEY(m) : m) > 0) {
907 prev = m;
908 m = bkey_next(m);
909 }
910
911 /* prev is in the tree, if we merge we're done */
912 status = BTREE_INSERT_STATUS_BACK_MERGE;
913 if (prev &&
914 bch_bkey_try_merge(b, prev, k))
915 goto merged;
916#if 0
917 status = BTREE_INSERT_STATUS_OVERWROTE;
918 if (m != bset_bkey_last(i) &&
919 KEY_PTRS(m) == KEY_PTRS(k) && !KEY_SIZE(m))
920 goto copy;
921#endif
922 status = BTREE_INSERT_STATUS_FRONT_MERGE;
923 if (m != bset_bkey_last(i) &&
924 bch_bkey_try_merge(b, k, m))
925 goto copy;
926
927 bch_bset_insert(b, m, k);
928copy: bkey_copy(m, k);
929merged:
930 return status;
931}
932
933/* Lookup */
934
935struct bset_search_iter {
936 struct bkey *l, *r;
937};
938
939static struct bset_search_iter bset_search_write_set(struct bset_tree *t,
940 const struct bkey *search)
941{
942 unsigned int li = 0, ri = t->size;
943
944 while (li + 1 != ri) {
945 unsigned int m = (li + ri) >> 1;
946
947 if (bkey_cmp(table_to_bkey(t, m), search) > 0)
948 ri = m;
949 else
950 li = m;
951 }
952
953 return (struct bset_search_iter) {
954 table_to_bkey(t, li),
955 ri < t->size ? table_to_bkey(t, ri) : bset_bkey_last(t->data)
956 };
957}
958
959static struct bset_search_iter bset_search_tree(struct bset_tree *t,
960 const struct bkey *search)
961{
962 struct bkey *l, *r;
963 struct bkey_float *f;
964 unsigned int inorder, j, n = 1;
965
966 do {
967 unsigned int p = n << 4;
968
969 if (p < t->size)
970 prefetch(&t->tree[p]);
971
972 j = n;
973 f = &t->tree[j];
974
975 if (likely(f->exponent != 127)) {
976 if (f->mantissa >= bfloat_mantissa(search, f))
977 n = j * 2;
978 else
979 n = j * 2 + 1;
980 } else {
981 if (bkey_cmp(tree_to_bkey(t, j), search) > 0)
982 n = j * 2;
983 else
984 n = j * 2 + 1;
985 }
986 } while (n < t->size);
987
988 inorder = to_inorder(j, t);
989
990 /*
991 * n would have been the node we recursed to - the low bit tells us if
992 * we recursed left or recursed right.
993 */
994 if (n & 1) {
995 l = cacheline_to_bkey(t, inorder, f->m);
996
997 if (++inorder != t->size) {
998 f = &t->tree[inorder_next(j, t->size)];
999 r = cacheline_to_bkey(t, inorder, f->m);
1000 } else
1001 r = bset_bkey_last(t->data);
1002 } else {
1003 r = cacheline_to_bkey(t, inorder, f->m);
1004
1005 if (--inorder) {
1006 f = &t->tree[inorder_prev(j, t->size)];
1007 l = cacheline_to_bkey(t, inorder, f->m);
1008 } else
1009 l = t->data->start;
1010 }
1011
1012 return (struct bset_search_iter) {l, r};
1013}
1014
1015struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
1016 const struct bkey *search)
1017{
1018 struct bset_search_iter i;
1019
1020 /*
1021 * First, we search for a cacheline, then lastly we do a linear search
1022 * within that cacheline.
1023 *
1024 * To search for the cacheline, there's three different possibilities:
1025 * * The set is too small to have a search tree, so we just do a linear
1026 * search over the whole set.
1027 * * The set is the one we're currently inserting into; keeping a full
1028 * auxiliary search tree up to date would be too expensive, so we
1029 * use a much simpler lookup table to do a binary search -
1030 * bset_search_write_set().
1031 * * Or we use the auxiliary search tree we constructed earlier -
1032 * bset_search_tree()
1033 */
1034
1035 if (unlikely(!t->size)) {
1036 i.l = t->data->start;
1037 i.r = bset_bkey_last(t->data);
1038 } else if (bset_written(b, t)) {
1039 /*
1040 * Each node in the auxiliary search tree covers a certain range
1041 * of bits, and keys above and below the set it covers might
1042 * differ outside those bits - so we have to special case the
1043 * start and end - handle that here:
1044 */
1045
1046 if (unlikely(bkey_cmp(search, &t->end) >= 0))
1047 return bset_bkey_last(t->data);
1048
1049 if (unlikely(bkey_cmp(search, t->data->start) < 0))
1050 return t->data->start;
1051
1052 i = bset_search_tree(t, search);
1053 } else {
1054 BUG_ON(!b->nsets &&
1055 t->size < bkey_to_cacheline(t, bset_bkey_last(t->data)));
1056
1057 i = bset_search_write_set(t, search);
1058 }
1059
1060 if (btree_keys_expensive_checks(b)) {
1061 BUG_ON(bset_written(b, t) &&
1062 i.l != t->data->start &&
1063 bkey_cmp(tree_to_prev_bkey(t,
1064 inorder_to_tree(bkey_to_cacheline(t, i.l), t)),
1065 search) > 0);
1066
1067 BUG_ON(i.r != bset_bkey_last(t->data) &&
1068 bkey_cmp(i.r, search) <= 0);
1069 }
1070
1071 while (likely(i.l != i.r) &&
1072 bkey_cmp(i.l, search) <= 0)
1073 i.l = bkey_next(i.l);
1074
1075 return i.l;
1076}
1077
1078/* Btree iterator */
1079
1080typedef bool (btree_iter_cmp_fn)(struct btree_iter_set,
1081 struct btree_iter_set);
1082
1083static inline bool btree_iter_cmp(struct btree_iter_set l,
1084 struct btree_iter_set r)
1085{
1086 return bkey_cmp(l.k, r.k) > 0;
1087}
1088
1089static inline bool btree_iter_end(struct btree_iter *iter)
1090{
1091 return !iter->used;
1092}
1093
1094void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
1095 struct bkey *end)
1096{
1097 if (k != end)
1098 BUG_ON(!heap_add(iter,
1099 ((struct btree_iter_set) { k, end }),
1100 btree_iter_cmp));
1101}
1102
1103static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
1104 struct btree_iter *iter,
1105 struct bkey *search,
1106 struct bset_tree *start)
1107{
1108 struct bkey *ret = NULL;
1109
1110 iter->size = ARRAY_SIZE(iter->data);
1111 iter->used = 0;
1112
1113#ifdef CONFIG_BCACHE_DEBUG
1114 iter->b = b;
1115#endif
1116
1117 for (; start <= bset_tree_last(b); start++) {
1118 ret = bch_bset_search(b, start, search);
1119 bch_btree_iter_push(iter, ret, bset_bkey_last(start->data));
1120 }
1121
1122 return ret;
1123}
1124
1125struct bkey *bch_btree_iter_init(struct btree_keys *b,
1126 struct btree_iter *iter,
1127 struct bkey *search)
1128{
1129 return __bch_btree_iter_init(b, iter, search, b->set);
1130}
1131
1132static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
1133 btree_iter_cmp_fn *cmp)
1134{
1135 struct btree_iter_set b __maybe_unused;
1136 struct bkey *ret = NULL;
1137
1138 if (!btree_iter_end(iter)) {
1139 bch_btree_iter_next_check(iter);
1140
1141 ret = iter->data->k;
1142 iter->data->k = bkey_next(iter->data->k);
1143
1144 if (iter->data->k > iter->data->end) {
1145 WARN_ONCE(1, "bset was corrupt!\n");
1146 iter->data->k = iter->data->end;
1147 }
1148
1149 if (iter->data->k == iter->data->end)
1150 heap_pop(iter, b, cmp);
1151 else
1152 heap_sift(iter, 0, cmp);
1153 }
1154
1155 return ret;
1156}
1157
1158struct bkey *bch_btree_iter_next(struct btree_iter *iter)
1159{
1160 return __bch_btree_iter_next(iter, btree_iter_cmp);
1161
1162}
1163
1164struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,
1165 struct btree_keys *b, ptr_filter_fn fn)
1166{
1167 struct bkey *ret;
1168
1169 do {
1170 ret = bch_btree_iter_next(iter);
1171 } while (ret && fn(b, ret));
1172
1173 return ret;
1174}
1175
1176/* Mergesort */
1177
1178void bch_bset_sort_state_free(struct bset_sort_state *state)
1179{
1180 mempool_exit(&state->pool);
1181}
1182
1183int bch_bset_sort_state_init(struct bset_sort_state *state,
1184 unsigned int page_order)
1185{
1186 spin_lock_init(&state->time.lock);
1187
1188 state->page_order = page_order;
1189 state->crit_factor = int_sqrt(1 << page_order);
1190
1191 return mempool_init_page_pool(&state->pool, 1, page_order);
1192}
1193
1194static void btree_mergesort(struct btree_keys *b, struct bset *out,
1195 struct btree_iter *iter,
1196 bool fixup, bool remove_stale)
1197{
1198 int i;
1199 struct bkey *k, *last = NULL;
1200 BKEY_PADDED(k) tmp;
1201 bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale
1202 ? bch_ptr_bad
1203 : bch_ptr_invalid;
1204
1205 /* Heapify the iterator, using our comparison function */
1206 for (i = iter->used / 2 - 1; i >= 0; --i)
1207 heap_sift(iter, i, b->ops->sort_cmp);
1208
1209 while (!btree_iter_end(iter)) {
1210 if (b->ops->sort_fixup && fixup)
1211 k = b->ops->sort_fixup(iter, &tmp.k);
1212 else
1213 k = NULL;
1214
1215 if (!k)
1216 k = __bch_btree_iter_next(iter, b->ops->sort_cmp);
1217
1218 if (bad(b, k))
1219 continue;
1220
1221 if (!last) {
1222 last = out->start;
1223 bkey_copy(last, k);
1224 } else if (!bch_bkey_try_merge(b, last, k)) {
1225 last = bkey_next(last);
1226 bkey_copy(last, k);
1227 }
1228 }
1229
1230 out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0;
1231
1232 pr_debug("sorted %i keys\n", out->keys);
1233}
1234
1235static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
1236 unsigned int start, unsigned int order, bool fixup,
1237 struct bset_sort_state *state)
1238{
1239 uint64_t start_time;
1240 bool used_mempool = false;
1241 struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOWAIT,
1242 order);
1243 if (!out) {
1244 struct page *outp;
1245
1246 BUG_ON(order > state->page_order);
1247
1248 outp = mempool_alloc(&state->pool, GFP_NOIO);
1249 out = page_address(outp);
1250 used_mempool = true;
1251 order = state->page_order;
1252 }
1253
1254 start_time = local_clock();
1255
1256 btree_mergesort(b, out, iter, fixup, false);
1257 b->nsets = start;
1258
1259 if (!start && order == b->page_order) {
1260 /*
1261 * Our temporary buffer is the same size as the btree node's
1262 * buffer, we can just swap buffers instead of doing a big
1263 * memcpy()
1264 *
1265 * Don't worry event 'out' is allocated from mempool, it can
1266 * still be swapped here. Because state->pool is a page mempool
1267 * created by mempool_init_page_pool(), which allocates
1268 * pages by alloc_pages() indeed.
1269 */
1270
1271 out->magic = b->set->data->magic;
1272 out->seq = b->set->data->seq;
1273 out->version = b->set->data->version;
1274 swap(out, b->set->data);
1275 } else {
1276 b->set[start].data->keys = out->keys;
1277 memcpy(b->set[start].data->start, out->start,
1278 (void *) bset_bkey_last(out) - (void *) out->start);
1279 }
1280
1281 if (used_mempool)
1282 mempool_free(virt_to_page(out), &state->pool);
1283 else
1284 free_pages((unsigned long) out, order);
1285
1286 bch_bset_build_written_tree(b);
1287
1288 if (!start)
1289 bch_time_stats_update(&state->time, start_time);
1290}
1291
1292void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
1293 struct bset_sort_state *state)
1294{
1295 size_t order = b->page_order, keys = 0;
1296 struct btree_iter iter;
1297 int oldsize = bch_count_data(b);
1298
1299 __bch_btree_iter_init(b, &iter, NULL, &b->set[start]);
1300
1301 if (start) {
1302 unsigned int i;
1303
1304 for (i = start; i <= b->nsets; i++)
1305 keys += b->set[i].data->keys;
1306
1307 order = get_order(__set_bytes(b->set->data, keys));
1308 }
1309
1310 __btree_sort(b, &iter, start, order, false, state);
1311
1312 EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize);
1313}
1314
1315void bch_btree_sort_and_fix_extents(struct btree_keys *b,
1316 struct btree_iter *iter,
1317 struct bset_sort_state *state)
1318{
1319 __btree_sort(b, iter, 0, b->page_order, true, state);
1320}
1321
1322void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new,
1323 struct bset_sort_state *state)
1324{
1325 uint64_t start_time = local_clock();
1326 struct btree_iter iter;
1327
1328 bch_btree_iter_init(b, &iter, NULL);
1329
1330 btree_mergesort(b, new->set->data, &iter, false, true);
1331
1332 bch_time_stats_update(&state->time, start_time);
1333
1334 new->set->size = 0; // XXX: why?
1335}
1336
1337#define SORT_CRIT (4096 / sizeof(uint64_t))
1338
1339void bch_btree_sort_lazy(struct btree_keys *b, struct bset_sort_state *state)
1340{
1341 unsigned int crit = SORT_CRIT;
1342 int i;
1343
1344 /* Don't sort if nothing to do */
1345 if (!b->nsets)
1346 goto out;
1347
1348 for (i = b->nsets - 1; i >= 0; --i) {
1349 crit *= state->crit_factor;
1350
1351 if (b->set[i].data->keys < crit) {
1352 bch_btree_sort_partial(b, i, state);
1353 return;
1354 }
1355 }
1356
1357 /* Sort if we'd overflow */
1358 if (b->nsets + 1 == MAX_BSETS) {
1359 bch_btree_sort(b, state);
1360 return;
1361 }
1362
1363out:
1364 bch_bset_build_written_tree(b);
1365}
1366
1367void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats)
1368{
1369 unsigned int i;
1370
1371 for (i = 0; i <= b->nsets; i++) {
1372 struct bset_tree *t = &b->set[i];
1373 size_t bytes = t->data->keys * sizeof(uint64_t);
1374 size_t j;
1375
1376 if (bset_written(b, t)) {
1377 stats->sets_written++;
1378 stats->bytes_written += bytes;
1379
1380 stats->floats += t->size - 1;
1381
1382 for (j = 1; j < t->size; j++)
1383 if (t->tree[j].exponent == 127)
1384 stats->failed++;
1385 } else {
1386 stats->sets_unwritten++;
1387 stats->bytes_unwritten += bytes;
1388 }
1389 }
1390}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Code for working with individual keys, and sorted sets of keys with in a
4 * btree node
5 *
6 * Copyright 2012 Google, Inc.
7 */
8
9#define pr_fmt(fmt) "bcache: %s() " fmt, __func__
10
11#include "util.h"
12#include "bset.h"
13
14#include <linux/console.h>
15#include <linux/sched/clock.h>
16#include <linux/random.h>
17#include <linux/prefetch.h>
18
19#ifdef CONFIG_BCACHE_DEBUG
20
21void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned int set)
22{
23 struct bkey *k, *next;
24
25 for (k = i->start; k < bset_bkey_last(i); k = next) {
26 next = bkey_next(k);
27
28 pr_err("block %u key %u/%u: ", set,
29 (unsigned int) ((u64 *) k - i->d), i->keys);
30
31 if (b->ops->key_dump)
32 b->ops->key_dump(b, k);
33 else
34 pr_cont("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k));
35
36 if (next < bset_bkey_last(i) &&
37 bkey_cmp(k, b->ops->is_extents ?
38 &START_KEY(next) : next) > 0)
39 pr_err("Key skipped backwards\n");
40 }
41}
42
43void bch_dump_bucket(struct btree_keys *b)
44{
45 unsigned int i;
46
47 console_lock();
48 for (i = 0; i <= b->nsets; i++)
49 bch_dump_bset(b, b->set[i].data,
50 bset_sector_offset(b, b->set[i].data));
51 console_unlock();
52}
53
54int __bch_count_data(struct btree_keys *b)
55{
56 unsigned int ret = 0;
57 struct btree_iter iter;
58 struct bkey *k;
59
60 min_heap_init(&iter.heap, NULL, MAX_BSETS);
61
62 if (b->ops->is_extents)
63 for_each_key(b, k, &iter)
64 ret += KEY_SIZE(k);
65 return ret;
66}
67
68void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
69{
70 va_list args;
71 struct bkey *k, *p = NULL;
72 struct btree_iter iter;
73 const char *err;
74
75 min_heap_init(&iter.heap, NULL, MAX_BSETS);
76
77 for_each_key(b, k, &iter) {
78 if (b->ops->is_extents) {
79 err = "Keys out of order";
80 if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
81 goto bug;
82
83 if (bch_ptr_invalid(b, k))
84 continue;
85
86 err = "Overlapping keys";
87 if (p && bkey_cmp(p, &START_KEY(k)) > 0)
88 goto bug;
89 } else {
90 if (bch_ptr_bad(b, k))
91 continue;
92
93 err = "Duplicate keys";
94 if (p && !bkey_cmp(p, k))
95 goto bug;
96 }
97 p = k;
98 }
99#if 0
100 err = "Key larger than btree node key";
101 if (p && bkey_cmp(p, &b->key) > 0)
102 goto bug;
103#endif
104 return;
105bug:
106 bch_dump_bucket(b);
107
108 va_start(args, fmt);
109 vprintk(fmt, args);
110 va_end(args);
111
112 panic("bch_check_keys error: %s:\n", err);
113}
114
115static void bch_btree_iter_next_check(struct btree_iter *iter)
116{
117 struct bkey *k = iter->heap.data->k, *next = bkey_next(k);
118
119 if (next < iter->heap.data->end &&
120 bkey_cmp(k, iter->b->ops->is_extents ?
121 &START_KEY(next) : next) > 0) {
122 bch_dump_bucket(iter->b);
123 panic("Key skipped backwards\n");
124 }
125}
126
127#else
128
129static inline void bch_btree_iter_next_check(struct btree_iter *iter) {}
130
131#endif
132
133/* Keylists */
134
135int __bch_keylist_realloc(struct keylist *l, unsigned int u64s)
136{
137 size_t oldsize = bch_keylist_nkeys(l);
138 size_t newsize = oldsize + u64s;
139 uint64_t *old_keys = l->keys_p == l->inline_keys ? NULL : l->keys_p;
140 uint64_t *new_keys;
141
142 newsize = roundup_pow_of_two(newsize);
143
144 if (newsize <= KEYLIST_INLINE ||
145 roundup_pow_of_two(oldsize) == newsize)
146 return 0;
147
148 new_keys = krealloc(old_keys, sizeof(uint64_t) * newsize, GFP_NOIO);
149
150 if (!new_keys)
151 return -ENOMEM;
152
153 if (!old_keys)
154 memcpy(new_keys, l->inline_keys, sizeof(uint64_t) * oldsize);
155
156 l->keys_p = new_keys;
157 l->top_p = new_keys + oldsize;
158
159 return 0;
160}
161
162/* Pop the top key of keylist by pointing l->top to its previous key */
163struct bkey *bch_keylist_pop(struct keylist *l)
164{
165 struct bkey *k = l->keys;
166
167 if (k == l->top)
168 return NULL;
169
170 while (bkey_next(k) != l->top)
171 k = bkey_next(k);
172
173 return l->top = k;
174}
175
176/* Pop the bottom key of keylist and update l->top_p */
177void bch_keylist_pop_front(struct keylist *l)
178{
179 l->top_p -= bkey_u64s(l->keys);
180
181 memmove(l->keys,
182 bkey_next(l->keys),
183 bch_keylist_bytes(l));
184}
185
186/* Key/pointer manipulation */
187
188void bch_bkey_copy_single_ptr(struct bkey *dest, const struct bkey *src,
189 unsigned int i)
190{
191 BUG_ON(i > KEY_PTRS(src));
192
193 /* Only copy the header, key, and one pointer. */
194 memcpy(dest, src, 2 * sizeof(uint64_t));
195 dest->ptr[0] = src->ptr[i];
196 SET_KEY_PTRS(dest, 1);
197 /* We didn't copy the checksum so clear that bit. */
198 SET_KEY_CSUM(dest, 0);
199}
200
201bool __bch_cut_front(const struct bkey *where, struct bkey *k)
202{
203 unsigned int i, len = 0;
204
205 if (bkey_cmp(where, &START_KEY(k)) <= 0)
206 return false;
207
208 if (bkey_cmp(where, k) < 0)
209 len = KEY_OFFSET(k) - KEY_OFFSET(where);
210 else
211 bkey_copy_key(k, where);
212
213 for (i = 0; i < KEY_PTRS(k); i++)
214 SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + KEY_SIZE(k) - len);
215
216 BUG_ON(len > KEY_SIZE(k));
217 SET_KEY_SIZE(k, len);
218 return true;
219}
220
221bool __bch_cut_back(const struct bkey *where, struct bkey *k)
222{
223 unsigned int len = 0;
224
225 if (bkey_cmp(where, k) >= 0)
226 return false;
227
228 BUG_ON(KEY_INODE(where) != KEY_INODE(k));
229
230 if (bkey_cmp(where, &START_KEY(k)) > 0)
231 len = KEY_OFFSET(where) - KEY_START(k);
232
233 bkey_copy_key(k, where);
234
235 BUG_ON(len > KEY_SIZE(k));
236 SET_KEY_SIZE(k, len);
237 return true;
238}
239
240/* Auxiliary search trees */
241
242/* 32 bits total: */
243#define BKEY_MID_BITS 3
244#define BKEY_EXPONENT_BITS 7
245#define BKEY_MANTISSA_BITS (32 - BKEY_MID_BITS - BKEY_EXPONENT_BITS)
246#define BKEY_MANTISSA_MASK ((1 << BKEY_MANTISSA_BITS) - 1)
247
248struct bkey_float {
249 unsigned int exponent:BKEY_EXPONENT_BITS;
250 unsigned int m:BKEY_MID_BITS;
251 unsigned int mantissa:BKEY_MANTISSA_BITS;
252} __packed;
253
254/*
255 * BSET_CACHELINE was originally intended to match the hardware cacheline size -
256 * it used to be 64, but I realized the lookup code would touch slightly less
257 * memory if it was 128.
258 *
259 * It definites the number of bytes (in struct bset) per struct bkey_float in
260 * the auxiliar search tree - when we're done searching the bset_float tree we
261 * have this many bytes left that we do a linear search over.
262 *
263 * Since (after level 5) every level of the bset_tree is on a new cacheline,
264 * we're touching one fewer cacheline in the bset tree in exchange for one more
265 * cacheline in the linear search - but the linear search might stop before it
266 * gets to the second cacheline.
267 */
268
269#define BSET_CACHELINE 128
270
271/* Space required for the btree node keys */
272static inline size_t btree_keys_bytes(struct btree_keys *b)
273{
274 return PAGE_SIZE << b->page_order;
275}
276
277static inline size_t btree_keys_cachelines(struct btree_keys *b)
278{
279 return btree_keys_bytes(b) / BSET_CACHELINE;
280}
281
282/* Space required for the auxiliary search trees */
283static inline size_t bset_tree_bytes(struct btree_keys *b)
284{
285 return btree_keys_cachelines(b) * sizeof(struct bkey_float);
286}
287
288/* Space required for the prev pointers */
289static inline size_t bset_prev_bytes(struct btree_keys *b)
290{
291 return btree_keys_cachelines(b) * sizeof(uint8_t);
292}
293
294/* Memory allocation */
295
296void bch_btree_keys_free(struct btree_keys *b)
297{
298 struct bset_tree *t = b->set;
299
300 if (bset_prev_bytes(b) < PAGE_SIZE)
301 kfree(t->prev);
302 else
303 free_pages((unsigned long) t->prev,
304 get_order(bset_prev_bytes(b)));
305
306 if (bset_tree_bytes(b) < PAGE_SIZE)
307 kfree(t->tree);
308 else
309 free_pages((unsigned long) t->tree,
310 get_order(bset_tree_bytes(b)));
311
312 free_pages((unsigned long) t->data, b->page_order);
313
314 t->prev = NULL;
315 t->tree = NULL;
316 t->data = NULL;
317}
318
319int bch_btree_keys_alloc(struct btree_keys *b,
320 unsigned int page_order,
321 gfp_t gfp)
322{
323 struct bset_tree *t = b->set;
324
325 BUG_ON(t->data);
326
327 b->page_order = page_order;
328
329 t->data = (void *) __get_free_pages(__GFP_COMP|gfp, b->page_order);
330 if (!t->data)
331 goto err;
332
333 t->tree = bset_tree_bytes(b) < PAGE_SIZE
334 ? kmalloc(bset_tree_bytes(b), gfp)
335 : (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b)));
336 if (!t->tree)
337 goto err;
338
339 t->prev = bset_prev_bytes(b) < PAGE_SIZE
340 ? kmalloc(bset_prev_bytes(b), gfp)
341 : (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b)));
342 if (!t->prev)
343 goto err;
344
345 return 0;
346err:
347 bch_btree_keys_free(b);
348 return -ENOMEM;
349}
350
351void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
352 bool *expensive_debug_checks)
353{
354 b->ops = ops;
355 b->expensive_debug_checks = expensive_debug_checks;
356 b->nsets = 0;
357 b->last_set_unwritten = 0;
358
359 /*
360 * struct btree_keys in embedded in struct btree, and struct
361 * bset_tree is embedded into struct btree_keys. They are all
362 * initialized as 0 by kzalloc() in mca_bucket_alloc(), and
363 * b->set[0].data is allocated in bch_btree_keys_alloc(), so we
364 * don't have to initiate b->set[].size and b->set[].data here
365 * any more.
366 */
367}
368
369/* Binary tree stuff for auxiliary search trees */
370
371/*
372 * return array index next to j when does in-order traverse
373 * of a binary tree which is stored in a linear array
374 */
375static unsigned int inorder_next(unsigned int j, unsigned int size)
376{
377 if (j * 2 + 1 < size) {
378 j = j * 2 + 1;
379
380 while (j * 2 < size)
381 j *= 2;
382 } else
383 j >>= ffz(j) + 1;
384
385 return j;
386}
387
388/*
389 * return array index previous to j when does in-order traverse
390 * of a binary tree which is stored in a linear array
391 */
392static unsigned int inorder_prev(unsigned int j, unsigned int size)
393{
394 if (j * 2 < size) {
395 j = j * 2;
396
397 while (j * 2 + 1 < size)
398 j = j * 2 + 1;
399 } else
400 j >>= ffs(j);
401
402 return j;
403}
404
405/*
406 * I have no idea why this code works... and I'm the one who wrote it
407 *
408 * However, I do know what it does:
409 * Given a binary tree constructed in an array (i.e. how you normally implement
410 * a heap), it converts a node in the tree - referenced by array index - to the
411 * index it would have if you did an inorder traversal.
412 *
413 * Also tested for every j, size up to size somewhere around 6 million.
414 *
415 * The binary tree starts at array index 1, not 0
416 * extra is a function of size:
417 * extra = (size - rounddown_pow_of_two(size - 1)) << 1;
418 */
419static unsigned int __to_inorder(unsigned int j,
420 unsigned int size,
421 unsigned int extra)
422{
423 unsigned int b = fls(j);
424 unsigned int shift = fls(size - 1) - b;
425
426 j ^= 1U << (b - 1);
427 j <<= 1;
428 j |= 1;
429 j <<= shift;
430
431 if (j > extra)
432 j -= (j - extra) >> 1;
433
434 return j;
435}
436
437/*
438 * Return the cacheline index in bset_tree->data, where j is index
439 * from a linear array which stores the auxiliar binary tree
440 */
441static unsigned int to_inorder(unsigned int j, struct bset_tree *t)
442{
443 return __to_inorder(j, t->size, t->extra);
444}
445
446static unsigned int __inorder_to_tree(unsigned int j,
447 unsigned int size,
448 unsigned int extra)
449{
450 unsigned int shift;
451
452 if (j > extra)
453 j += j - extra;
454
455 shift = ffs(j);
456
457 j >>= shift;
458 j |= roundup_pow_of_two(size) >> shift;
459
460 return j;
461}
462
463/*
464 * Return an index from a linear array which stores the auxiliar binary
465 * tree, j is the cacheline index of t->data.
466 */
467static unsigned int inorder_to_tree(unsigned int j, struct bset_tree *t)
468{
469 return __inorder_to_tree(j, t->size, t->extra);
470}
471
472#if 0
473void inorder_test(void)
474{
475 unsigned long done = 0;
476 ktime_t start = ktime_get();
477
478 for (unsigned int size = 2;
479 size < 65536000;
480 size++) {
481 unsigned int extra =
482 (size - rounddown_pow_of_two(size - 1)) << 1;
483 unsigned int i = 1, j = rounddown_pow_of_two(size - 1);
484
485 if (!(size % 4096))
486 pr_notice("loop %u, %llu per us\n", size,
487 done / ktime_us_delta(ktime_get(), start));
488
489 while (1) {
490 if (__inorder_to_tree(i, size, extra) != j)
491 panic("size %10u j %10u i %10u", size, j, i);
492
493 if (__to_inorder(j, size, extra) != i)
494 panic("size %10u j %10u i %10u", size, j, i);
495
496 if (j == rounddown_pow_of_two(size) - 1)
497 break;
498
499 BUG_ON(inorder_prev(inorder_next(j, size), size) != j);
500
501 j = inorder_next(j, size);
502 i++;
503 }
504
505 done += size - 1;
506 }
507}
508#endif
509
510/*
511 * Cacheline/offset <-> bkey pointer arithmetic:
512 *
513 * t->tree is a binary search tree in an array; each node corresponds to a key
514 * in one cacheline in t->set (BSET_CACHELINE bytes).
515 *
516 * This means we don't have to store the full index of the key that a node in
517 * the binary tree points to; to_inorder() gives us the cacheline, and then
518 * bkey_float->m gives us the offset within that cacheline, in units of 8 bytes.
519 *
520 * cacheline_to_bkey() and friends abstract out all the pointer arithmetic to
521 * make this work.
522 *
523 * To construct the bfloat for an arbitrary key we need to know what the key
524 * immediately preceding it is: we have to check if the two keys differ in the
525 * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size
526 * of the previous key so we can walk backwards to it from t->tree[j]'s key.
527 */
528
529static struct bkey *cacheline_to_bkey(struct bset_tree *t,
530 unsigned int cacheline,
531 unsigned int offset)
532{
533 return ((void *) t->data) + cacheline * BSET_CACHELINE + offset * 8;
534}
535
536static unsigned int bkey_to_cacheline(struct bset_tree *t, struct bkey *k)
537{
538 return ((void *) k - (void *) t->data) / BSET_CACHELINE;
539}
540
541static unsigned int bkey_to_cacheline_offset(struct bset_tree *t,
542 unsigned int cacheline,
543 struct bkey *k)
544{
545 return (u64 *) k - (u64 *) cacheline_to_bkey(t, cacheline, 0);
546}
547
548static struct bkey *tree_to_bkey(struct bset_tree *t, unsigned int j)
549{
550 return cacheline_to_bkey(t, to_inorder(j, t), t->tree[j].m);
551}
552
553static struct bkey *tree_to_prev_bkey(struct bset_tree *t, unsigned int j)
554{
555 return (void *) (((uint64_t *) tree_to_bkey(t, j)) - t->prev[j]);
556}
557
558/*
559 * For the write set - the one we're currently inserting keys into - we don't
560 * maintain a full search tree, we just keep a simple lookup table in t->prev.
561 */
562static struct bkey *table_to_bkey(struct bset_tree *t, unsigned int cacheline)
563{
564 return cacheline_to_bkey(t, cacheline, t->prev[cacheline]);
565}
566
567static inline uint64_t shrd128(uint64_t high, uint64_t low, uint8_t shift)
568{
569 low >>= shift;
570 low |= (high << 1) << (63U - shift);
571 return low;
572}
573
574/*
575 * Calculate mantissa value for struct bkey_float.
576 * If most significant bit of f->exponent is not set, then
577 * - f->exponent >> 6 is 0
578 * - p[0] points to bkey->low
579 * - p[-1] borrows bits from KEY_INODE() of bkey->high
580 * if most isgnificant bits of f->exponent is set, then
581 * - f->exponent >> 6 is 1
582 * - p[0] points to bits from KEY_INODE() of bkey->high
583 * - p[-1] points to other bits from KEY_INODE() of
584 * bkey->high too.
585 * See make_bfloat() to check when most significant bit of f->exponent
586 * is set or not.
587 */
588static inline unsigned int bfloat_mantissa(const struct bkey *k,
589 struct bkey_float *f)
590{
591 const uint64_t *p = &k->low - (f->exponent >> 6);
592
593 return shrd128(p[-1], p[0], f->exponent & 63) & BKEY_MANTISSA_MASK;
594}
595
596static void make_bfloat(struct bset_tree *t, unsigned int j)
597{
598 struct bkey_float *f = &t->tree[j];
599 struct bkey *m = tree_to_bkey(t, j);
600 struct bkey *p = tree_to_prev_bkey(t, j);
601
602 struct bkey *l = is_power_of_2(j)
603 ? t->data->start
604 : tree_to_prev_bkey(t, j >> ffs(j));
605
606 struct bkey *r = is_power_of_2(j + 1)
607 ? bset_bkey_idx(t->data, t->data->keys - bkey_u64s(&t->end))
608 : tree_to_bkey(t, j >> (ffz(j) + 1));
609
610 BUG_ON(m < l || m > r);
611 BUG_ON(bkey_next(p) != m);
612
613 /*
614 * If l and r have different KEY_INODE values (different backing
615 * device), f->exponent records how many least significant bits
616 * are different in KEY_INODE values and sets most significant
617 * bits to 1 (by +64).
618 * If l and r have same KEY_INODE value, f->exponent records
619 * how many different bits in least significant bits of bkey->low.
620 * See bfloat_mantiss() how the most significant bit of
621 * f->exponent is used to calculate bfloat mantissa value.
622 */
623 if (KEY_INODE(l) != KEY_INODE(r))
624 f->exponent = fls64(KEY_INODE(r) ^ KEY_INODE(l)) + 64;
625 else
626 f->exponent = fls64(r->low ^ l->low);
627
628 f->exponent = max_t(int, f->exponent - BKEY_MANTISSA_BITS, 0);
629
630 /*
631 * Setting f->exponent = 127 flags this node as failed, and causes the
632 * lookup code to fall back to comparing against the original key.
633 */
634
635 if (bfloat_mantissa(m, f) != bfloat_mantissa(p, f))
636 f->mantissa = bfloat_mantissa(m, f) - 1;
637 else
638 f->exponent = 127;
639}
640
641static void bset_alloc_tree(struct btree_keys *b, struct bset_tree *t)
642{
643 if (t != b->set) {
644 unsigned int j = roundup(t[-1].size,
645 64 / sizeof(struct bkey_float));
646
647 t->tree = t[-1].tree + j;
648 t->prev = t[-1].prev + j;
649 }
650
651 while (t < b->set + MAX_BSETS)
652 t++->size = 0;
653}
654
655static void bch_bset_build_unwritten_tree(struct btree_keys *b)
656{
657 struct bset_tree *t = bset_tree_last(b);
658
659 BUG_ON(b->last_set_unwritten);
660 b->last_set_unwritten = 1;
661
662 bset_alloc_tree(b, t);
663
664 if (t->tree != b->set->tree + btree_keys_cachelines(b)) {
665 t->prev[0] = bkey_to_cacheline_offset(t, 0, t->data->start);
666 t->size = 1;
667 }
668}
669
670void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
671{
672 if (i != b->set->data) {
673 b->set[++b->nsets].data = i;
674 i->seq = b->set->data->seq;
675 } else
676 get_random_bytes(&i->seq, sizeof(uint64_t));
677
678 i->magic = magic;
679 i->version = 0;
680 i->keys = 0;
681
682 bch_bset_build_unwritten_tree(b);
683}
684
685/*
686 * Build auxiliary binary tree 'struct bset_tree *t', this tree is used to
687 * accelerate bkey search in a btree node (pointed by bset_tree->data in
688 * memory). After search in the auxiliar tree by calling bset_search_tree(),
689 * a struct bset_search_iter is returned which indicates range [l, r] from
690 * bset_tree->data where the searching bkey might be inside. Then a followed
691 * linear comparison does the exact search, see __bch_bset_search() for how
692 * the auxiliary tree is used.
693 */
694void bch_bset_build_written_tree(struct btree_keys *b)
695{
696 struct bset_tree *t = bset_tree_last(b);
697 struct bkey *prev = NULL, *k = t->data->start;
698 unsigned int j, cacheline = 1;
699
700 b->last_set_unwritten = 0;
701
702 bset_alloc_tree(b, t);
703
704 t->size = min_t(unsigned int,
705 bkey_to_cacheline(t, bset_bkey_last(t->data)),
706 b->set->tree + btree_keys_cachelines(b) - t->tree);
707
708 if (t->size < 2) {
709 t->size = 0;
710 return;
711 }
712
713 t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1;
714
715 /* First we figure out where the first key in each cacheline is */
716 for (j = inorder_next(0, t->size);
717 j;
718 j = inorder_next(j, t->size)) {
719 while (bkey_to_cacheline(t, k) < cacheline) {
720 prev = k;
721 k = bkey_next(k);
722 }
723
724 t->prev[j] = bkey_u64s(prev);
725 t->tree[j].m = bkey_to_cacheline_offset(t, cacheline++, k);
726 }
727
728 while (bkey_next(k) != bset_bkey_last(t->data))
729 k = bkey_next(k);
730
731 t->end = *k;
732
733 /* Then we build the tree */
734 for (j = inorder_next(0, t->size);
735 j;
736 j = inorder_next(j, t->size))
737 make_bfloat(t, j);
738}
739
740/* Insert */
741
742void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k)
743{
744 struct bset_tree *t;
745 unsigned int inorder, j = 1;
746
747 for (t = b->set; t <= bset_tree_last(b); t++)
748 if (k < bset_bkey_last(t->data))
749 goto found_set;
750
751 BUG();
752found_set:
753 if (!t->size || !bset_written(b, t))
754 return;
755
756 inorder = bkey_to_cacheline(t, k);
757
758 if (k == t->data->start)
759 goto fix_left;
760
761 if (bkey_next(k) == bset_bkey_last(t->data)) {
762 t->end = *k;
763 goto fix_right;
764 }
765
766 j = inorder_to_tree(inorder, t);
767
768 if (j &&
769 j < t->size &&
770 k == tree_to_bkey(t, j))
771fix_left: do {
772 make_bfloat(t, j);
773 j = j * 2;
774 } while (j < t->size);
775
776 j = inorder_to_tree(inorder + 1, t);
777
778 if (j &&
779 j < t->size &&
780 k == tree_to_prev_bkey(t, j))
781fix_right: do {
782 make_bfloat(t, j);
783 j = j * 2 + 1;
784 } while (j < t->size);
785}
786
787static void bch_bset_fix_lookup_table(struct btree_keys *b,
788 struct bset_tree *t,
789 struct bkey *k)
790{
791 unsigned int shift = bkey_u64s(k);
792 unsigned int j = bkey_to_cacheline(t, k);
793
794 /* We're getting called from btree_split() or btree_gc, just bail out */
795 if (!t->size)
796 return;
797
798 /*
799 * k is the key we just inserted; we need to find the entry in the
800 * lookup table for the first key that is strictly greater than k:
801 * it's either k's cacheline or the next one
802 */
803 while (j < t->size &&
804 table_to_bkey(t, j) <= k)
805 j++;
806
807 /*
808 * Adjust all the lookup table entries, and find a new key for any that
809 * have gotten too big
810 */
811 for (; j < t->size; j++) {
812 t->prev[j] += shift;
813
814 if (t->prev[j] > 7) {
815 k = table_to_bkey(t, j - 1);
816
817 while (k < cacheline_to_bkey(t, j, 0))
818 k = bkey_next(k);
819
820 t->prev[j] = bkey_to_cacheline_offset(t, j, k);
821 }
822 }
823
824 if (t->size == b->set->tree + btree_keys_cachelines(b) - t->tree)
825 return;
826
827 /* Possibly add a new entry to the end of the lookup table */
828
829 for (k = table_to_bkey(t, t->size - 1);
830 k != bset_bkey_last(t->data);
831 k = bkey_next(k))
832 if (t->size == bkey_to_cacheline(t, k)) {
833 t->prev[t->size] =
834 bkey_to_cacheline_offset(t, t->size, k);
835 t->size++;
836 }
837}
838
839/*
840 * Tries to merge l and r: l should be lower than r
841 * Returns true if we were able to merge. If we did merge, l will be the merged
842 * key, r will be untouched.
843 */
844bool bch_bkey_try_merge(struct btree_keys *b, struct bkey *l, struct bkey *r)
845{
846 if (!b->ops->key_merge)
847 return false;
848
849 /*
850 * Generic header checks
851 * Assumes left and right are in order
852 * Left and right must be exactly aligned
853 */
854 if (!bch_bkey_equal_header(l, r) ||
855 bkey_cmp(l, &START_KEY(r)))
856 return false;
857
858 return b->ops->key_merge(b, l, r);
859}
860
861void bch_bset_insert(struct btree_keys *b, struct bkey *where,
862 struct bkey *insert)
863{
864 struct bset_tree *t = bset_tree_last(b);
865
866 BUG_ON(!b->last_set_unwritten);
867 BUG_ON(bset_byte_offset(b, t->data) +
868 __set_bytes(t->data, t->data->keys + bkey_u64s(insert)) >
869 PAGE_SIZE << b->page_order);
870
871 memmove((uint64_t *) where + bkey_u64s(insert),
872 where,
873 (void *) bset_bkey_last(t->data) - (void *) where);
874
875 t->data->keys += bkey_u64s(insert);
876 bkey_copy(where, insert);
877 bch_bset_fix_lookup_table(b, t, where);
878}
879
880unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
881 struct bkey *replace_key)
882{
883 unsigned int status = BTREE_INSERT_STATUS_NO_INSERT;
884 struct bset *i = bset_tree_last(b)->data;
885 struct bkey *m, *prev = NULL;
886 struct btree_iter iter;
887 struct bkey preceding_key_on_stack = ZERO_KEY;
888 struct bkey *preceding_key_p = &preceding_key_on_stack;
889
890 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
891
892 min_heap_init(&iter.heap, NULL, MAX_BSETS);
893
894 /*
895 * If k has preceding key, preceding_key_p will be set to address
896 * of k's preceding key; otherwise preceding_key_p will be set
897 * to NULL inside preceding_key().
898 */
899 if (b->ops->is_extents)
900 preceding_key(&START_KEY(k), &preceding_key_p);
901 else
902 preceding_key(k, &preceding_key_p);
903
904 m = bch_btree_iter_init(b, &iter, preceding_key_p);
905
906 if (b->ops->insert_fixup(b, k, &iter, replace_key))
907 return status;
908
909 status = BTREE_INSERT_STATUS_INSERT;
910
911 while (m != bset_bkey_last(i) &&
912 bkey_cmp(k, b->ops->is_extents ? &START_KEY(m) : m) > 0) {
913 prev = m;
914 m = bkey_next(m);
915 }
916
917 /* prev is in the tree, if we merge we're done */
918 status = BTREE_INSERT_STATUS_BACK_MERGE;
919 if (prev &&
920 bch_bkey_try_merge(b, prev, k))
921 goto merged;
922#if 0
923 status = BTREE_INSERT_STATUS_OVERWROTE;
924 if (m != bset_bkey_last(i) &&
925 KEY_PTRS(m) == KEY_PTRS(k) && !KEY_SIZE(m))
926 goto copy;
927#endif
928 status = BTREE_INSERT_STATUS_FRONT_MERGE;
929 if (m != bset_bkey_last(i) &&
930 bch_bkey_try_merge(b, k, m))
931 goto copy;
932
933 bch_bset_insert(b, m, k);
934copy: bkey_copy(m, k);
935merged:
936 return status;
937}
938
939/* Lookup */
940
941struct bset_search_iter {
942 struct bkey *l, *r;
943};
944
945static struct bset_search_iter bset_search_write_set(struct bset_tree *t,
946 const struct bkey *search)
947{
948 unsigned int li = 0, ri = t->size;
949
950 while (li + 1 != ri) {
951 unsigned int m = (li + ri) >> 1;
952
953 if (bkey_cmp(table_to_bkey(t, m), search) > 0)
954 ri = m;
955 else
956 li = m;
957 }
958
959 return (struct bset_search_iter) {
960 table_to_bkey(t, li),
961 ri < t->size ? table_to_bkey(t, ri) : bset_bkey_last(t->data)
962 };
963}
964
965static struct bset_search_iter bset_search_tree(struct bset_tree *t,
966 const struct bkey *search)
967{
968 struct bkey *l, *r;
969 struct bkey_float *f;
970 unsigned int inorder, j, n = 1;
971
972 do {
973 unsigned int p = n << 4;
974
975 if (p < t->size)
976 prefetch(&t->tree[p]);
977
978 j = n;
979 f = &t->tree[j];
980
981 if (likely(f->exponent != 127)) {
982 if (f->mantissa >= bfloat_mantissa(search, f))
983 n = j * 2;
984 else
985 n = j * 2 + 1;
986 } else {
987 if (bkey_cmp(tree_to_bkey(t, j), search) > 0)
988 n = j * 2;
989 else
990 n = j * 2 + 1;
991 }
992 } while (n < t->size);
993
994 inorder = to_inorder(j, t);
995
996 /*
997 * n would have been the node we recursed to - the low bit tells us if
998 * we recursed left or recursed right.
999 */
1000 if (n & 1) {
1001 l = cacheline_to_bkey(t, inorder, f->m);
1002
1003 if (++inorder != t->size) {
1004 f = &t->tree[inorder_next(j, t->size)];
1005 r = cacheline_to_bkey(t, inorder, f->m);
1006 } else
1007 r = bset_bkey_last(t->data);
1008 } else {
1009 r = cacheline_to_bkey(t, inorder, f->m);
1010
1011 if (--inorder) {
1012 f = &t->tree[inorder_prev(j, t->size)];
1013 l = cacheline_to_bkey(t, inorder, f->m);
1014 } else
1015 l = t->data->start;
1016 }
1017
1018 return (struct bset_search_iter) {l, r};
1019}
1020
1021struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
1022 const struct bkey *search)
1023{
1024 struct bset_search_iter i;
1025
1026 /*
1027 * First, we search for a cacheline, then lastly we do a linear search
1028 * within that cacheline.
1029 *
1030 * To search for the cacheline, there's three different possibilities:
1031 * * The set is too small to have a search tree, so we just do a linear
1032 * search over the whole set.
1033 * * The set is the one we're currently inserting into; keeping a full
1034 * auxiliary search tree up to date would be too expensive, so we
1035 * use a much simpler lookup table to do a binary search -
1036 * bset_search_write_set().
1037 * * Or we use the auxiliary search tree we constructed earlier -
1038 * bset_search_tree()
1039 */
1040
1041 if (unlikely(!t->size)) {
1042 i.l = t->data->start;
1043 i.r = bset_bkey_last(t->data);
1044 } else if (bset_written(b, t)) {
1045 /*
1046 * Each node in the auxiliary search tree covers a certain range
1047 * of bits, and keys above and below the set it covers might
1048 * differ outside those bits - so we have to special case the
1049 * start and end - handle that here:
1050 */
1051
1052 if (unlikely(bkey_cmp(search, &t->end) >= 0))
1053 return bset_bkey_last(t->data);
1054
1055 if (unlikely(bkey_cmp(search, t->data->start) < 0))
1056 return t->data->start;
1057
1058 i = bset_search_tree(t, search);
1059 } else {
1060 BUG_ON(!b->nsets &&
1061 t->size < bkey_to_cacheline(t, bset_bkey_last(t->data)));
1062
1063 i = bset_search_write_set(t, search);
1064 }
1065
1066 if (btree_keys_expensive_checks(b)) {
1067 BUG_ON(bset_written(b, t) &&
1068 i.l != t->data->start &&
1069 bkey_cmp(tree_to_prev_bkey(t,
1070 inorder_to_tree(bkey_to_cacheline(t, i.l), t)),
1071 search) > 0);
1072
1073 BUG_ON(i.r != bset_bkey_last(t->data) &&
1074 bkey_cmp(i.r, search) <= 0);
1075 }
1076
1077 while (likely(i.l != i.r) &&
1078 bkey_cmp(i.l, search) <= 0)
1079 i.l = bkey_next(i.l);
1080
1081 return i.l;
1082}
1083
1084/* Btree iterator */
1085
1086typedef bool (new_btree_iter_cmp_fn)(const void *, const void *, void *);
1087
1088static inline bool new_btree_iter_cmp(const void *l, const void *r, void __always_unused *args)
1089{
1090 const struct btree_iter_set *_l = l;
1091 const struct btree_iter_set *_r = r;
1092
1093 return bkey_cmp(_l->k, _r->k) <= 0;
1094}
1095
1096static inline bool btree_iter_end(struct btree_iter *iter)
1097{
1098 return !iter->heap.nr;
1099}
1100
1101void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
1102 struct bkey *end)
1103{
1104 const struct min_heap_callbacks callbacks = {
1105 .less = new_btree_iter_cmp,
1106 .swp = NULL,
1107 };
1108
1109 if (k != end)
1110 BUG_ON(!min_heap_push(&iter->heap,
1111 &((struct btree_iter_set) { k, end }),
1112 &callbacks,
1113 NULL));
1114}
1115
1116static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
1117 struct btree_iter *iter,
1118 struct bkey *search,
1119 struct bset_tree *start)
1120{
1121 struct bkey *ret = NULL;
1122
1123 iter->heap.size = ARRAY_SIZE(iter->heap.preallocated);
1124 iter->heap.nr = 0;
1125
1126#ifdef CONFIG_BCACHE_DEBUG
1127 iter->b = b;
1128#endif
1129
1130 for (; start <= bset_tree_last(b); start++) {
1131 ret = bch_bset_search(b, start, search);
1132 bch_btree_iter_push(iter, ret, bset_bkey_last(start->data));
1133 }
1134
1135 return ret;
1136}
1137
1138struct bkey *bch_btree_iter_init(struct btree_keys *b,
1139 struct btree_iter *iter,
1140 struct bkey *search)
1141{
1142 return __bch_btree_iter_init(b, iter, search, b->set);
1143}
1144
1145static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
1146 new_btree_iter_cmp_fn *cmp)
1147{
1148 struct btree_iter_set b __maybe_unused;
1149 struct bkey *ret = NULL;
1150 const struct min_heap_callbacks callbacks = {
1151 .less = cmp,
1152 .swp = NULL,
1153 };
1154
1155 if (!btree_iter_end(iter)) {
1156 bch_btree_iter_next_check(iter);
1157
1158 ret = iter->heap.data->k;
1159 iter->heap.data->k = bkey_next(iter->heap.data->k);
1160
1161 if (iter->heap.data->k > iter->heap.data->end) {
1162 WARN_ONCE(1, "bset was corrupt!\n");
1163 iter->heap.data->k = iter->heap.data->end;
1164 }
1165
1166 if (iter->heap.data->k == iter->heap.data->end) {
1167 if (iter->heap.nr) {
1168 b = min_heap_peek(&iter->heap)[0];
1169 min_heap_pop(&iter->heap, &callbacks, NULL);
1170 }
1171 }
1172 else
1173 min_heap_sift_down(&iter->heap, 0, &callbacks, NULL);
1174 }
1175
1176 return ret;
1177}
1178
1179struct bkey *bch_btree_iter_next(struct btree_iter *iter)
1180{
1181 return __bch_btree_iter_next(iter, new_btree_iter_cmp);
1182
1183}
1184
1185struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,
1186 struct btree_keys *b, ptr_filter_fn fn)
1187{
1188 struct bkey *ret;
1189
1190 do {
1191 ret = bch_btree_iter_next(iter);
1192 } while (ret && fn(b, ret));
1193
1194 return ret;
1195}
1196
1197/* Mergesort */
1198
1199void bch_bset_sort_state_free(struct bset_sort_state *state)
1200{
1201 mempool_exit(&state->pool);
1202}
1203
1204int bch_bset_sort_state_init(struct bset_sort_state *state,
1205 unsigned int page_order)
1206{
1207 spin_lock_init(&state->time.lock);
1208
1209 state->page_order = page_order;
1210 state->crit_factor = int_sqrt(1 << page_order);
1211
1212 return mempool_init_page_pool(&state->pool, 1, page_order);
1213}
1214
1215static void btree_mergesort(struct btree_keys *b, struct bset *out,
1216 struct btree_iter *iter,
1217 bool fixup, bool remove_stale)
1218{
1219 struct bkey *k, *last = NULL;
1220 BKEY_PADDED(k) tmp;
1221 bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale
1222 ? bch_ptr_bad
1223 : bch_ptr_invalid;
1224 const struct min_heap_callbacks callbacks = {
1225 .less = b->ops->sort_cmp,
1226 .swp = NULL,
1227 };
1228
1229 /* Heapify the iterator, using our comparison function */
1230 min_heapify_all(&iter->heap, &callbacks, NULL);
1231
1232 while (!btree_iter_end(iter)) {
1233 if (b->ops->sort_fixup && fixup)
1234 k = b->ops->sort_fixup(iter, &tmp.k);
1235 else
1236 k = NULL;
1237
1238 if (!k)
1239 k = __bch_btree_iter_next(iter, b->ops->sort_cmp);
1240
1241 if (bad(b, k))
1242 continue;
1243
1244 if (!last) {
1245 last = out->start;
1246 bkey_copy(last, k);
1247 } else if (!bch_bkey_try_merge(b, last, k)) {
1248 last = bkey_next(last);
1249 bkey_copy(last, k);
1250 }
1251 }
1252
1253 out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0;
1254
1255 pr_debug("sorted %i keys\n", out->keys);
1256}
1257
1258static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
1259 unsigned int start, unsigned int order, bool fixup,
1260 struct bset_sort_state *state)
1261{
1262 uint64_t start_time;
1263 bool used_mempool = false;
1264 struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOWAIT,
1265 order);
1266 if (!out) {
1267 struct page *outp;
1268
1269 BUG_ON(order > state->page_order);
1270
1271 outp = mempool_alloc(&state->pool, GFP_NOIO);
1272 out = page_address(outp);
1273 used_mempool = true;
1274 order = state->page_order;
1275 }
1276
1277 start_time = local_clock();
1278
1279 btree_mergesort(b, out, iter, fixup, false);
1280 b->nsets = start;
1281
1282 if (!start && order == b->page_order) {
1283 /*
1284 * Our temporary buffer is the same size as the btree node's
1285 * buffer, we can just swap buffers instead of doing a big
1286 * memcpy()
1287 *
1288 * Don't worry event 'out' is allocated from mempool, it can
1289 * still be swapped here. Because state->pool is a page mempool
1290 * created by mempool_init_page_pool(), which allocates
1291 * pages by alloc_pages() indeed.
1292 */
1293
1294 out->magic = b->set->data->magic;
1295 out->seq = b->set->data->seq;
1296 out->version = b->set->data->version;
1297 swap(out, b->set->data);
1298 } else {
1299 b->set[start].data->keys = out->keys;
1300 memcpy(b->set[start].data->start, out->start,
1301 (void *) bset_bkey_last(out) - (void *) out->start);
1302 }
1303
1304 if (used_mempool)
1305 mempool_free(virt_to_page(out), &state->pool);
1306 else
1307 free_pages((unsigned long) out, order);
1308
1309 bch_bset_build_written_tree(b);
1310
1311 if (!start)
1312 bch_time_stats_update(&state->time, start_time);
1313}
1314
1315void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
1316 struct bset_sort_state *state)
1317{
1318 size_t order = b->page_order, keys = 0;
1319 struct btree_iter iter;
1320 int oldsize = bch_count_data(b);
1321
1322 min_heap_init(&iter.heap, NULL, MAX_BSETS);
1323 __bch_btree_iter_init(b, &iter, NULL, &b->set[start]);
1324
1325 if (start) {
1326 unsigned int i;
1327
1328 for (i = start; i <= b->nsets; i++)
1329 keys += b->set[i].data->keys;
1330
1331 order = get_order(__set_bytes(b->set->data, keys));
1332 }
1333
1334 __btree_sort(b, &iter, start, order, false, state);
1335
1336 EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize);
1337}
1338
1339void bch_btree_sort_and_fix_extents(struct btree_keys *b,
1340 struct btree_iter *iter,
1341 struct bset_sort_state *state)
1342{
1343 __btree_sort(b, iter, 0, b->page_order, true, state);
1344}
1345
1346void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new,
1347 struct bset_sort_state *state)
1348{
1349 uint64_t start_time = local_clock();
1350 struct btree_iter iter;
1351
1352 min_heap_init(&iter.heap, NULL, MAX_BSETS);
1353
1354 bch_btree_iter_init(b, &iter, NULL);
1355
1356 btree_mergesort(b, new->set->data, &iter, false, true);
1357
1358 bch_time_stats_update(&state->time, start_time);
1359
1360 new->set->size = 0; // XXX: why?
1361}
1362
1363#define SORT_CRIT (4096 / sizeof(uint64_t))
1364
1365void bch_btree_sort_lazy(struct btree_keys *b, struct bset_sort_state *state)
1366{
1367 unsigned int crit = SORT_CRIT;
1368 int i;
1369
1370 /* Don't sort if nothing to do */
1371 if (!b->nsets)
1372 goto out;
1373
1374 for (i = b->nsets - 1; i >= 0; --i) {
1375 crit *= state->crit_factor;
1376
1377 if (b->set[i].data->keys < crit) {
1378 bch_btree_sort_partial(b, i, state);
1379 return;
1380 }
1381 }
1382
1383 /* Sort if we'd overflow */
1384 if (b->nsets + 1 == MAX_BSETS) {
1385 bch_btree_sort(b, state);
1386 return;
1387 }
1388
1389out:
1390 bch_bset_build_written_tree(b);
1391}
1392
1393void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats)
1394{
1395 unsigned int i;
1396
1397 for (i = 0; i <= b->nsets; i++) {
1398 struct bset_tree *t = &b->set[i];
1399 size_t bytes = t->data->keys * sizeof(uint64_t);
1400 size_t j;
1401
1402 if (bset_written(b, t)) {
1403 stats->sets_written++;
1404 stats->bytes_written += bytes;
1405
1406 stats->floats += t->size - 1;
1407
1408 for (j = 1; j < t->size; j++)
1409 if (t->tree[j].exponent == 127)
1410 stats->failed++;
1411 } else {
1412 stats->sets_unwritten++;
1413 stats->bytes_unwritten += bytes;
1414 }
1415 }
1416}