1 // SPDX-License-Identifier: GPL-2.0
3 * Code for working with individual keys, and sorted sets of keys with in a
6 * Copyright 2012 Google, Inc.
10 #include "btree_cache.h"
12 #include "eytzinger.h"
16 #include <asm/unaligned.h>
17 #include <linux/console.h>
18 #include <linux/random.h>
19 #include <linux/prefetch.h>
21 static inline void __bch2_btree_node_iter_advance(struct btree_node_iter *,
24 static inline unsigned __btree_node_iter_used(struct btree_node_iter *iter)
26 unsigned n = ARRAY_SIZE(iter->data);
28 while (n && __btree_node_iter_set_end(iter, n - 1))
34 struct bset_tree *bch2_bkey_to_bset(struct btree *b, struct bkey_packed *k)
36 return bch2_bkey_to_bset_inlined(b, k);
40 * There are never duplicate live keys in the btree - but including keys that
41 * have been flagged as deleted (and will be cleaned up later) we _will_ see
44 * Thus the sort order is: usual key comparison first, but for keys that compare
45 * equal the deleted key(s) come first, and the (at most one) live version comes
48 * The main reason for this is insertion: to handle overwrites, we first iterate
49 * over keys that compare equal to our insert key, and then insert immediately
50 * prior to the first key greater than the key we're inserting - our insert
51 * position will be after all keys that compare equal to our insert key, which
52 * by the time we actually do the insert will all be deleted.
55 void bch2_dump_bset(struct bch_fs *c, struct btree *b,
56 struct bset *i, unsigned set)
58 struct bkey_packed *_k, *_n;
61 struct printbuf buf = PRINTBUF;
71 k = bkey_disassemble(b, _k, &uk);
75 bch2_bkey_val_to_text(&buf, c, k);
77 bch2_bkey_to_text(&buf, k.k);
78 printk(KERN_ERR "block %u key %5zu: %s\n", set,
79 _k->_data - i->_data, buf.buf);
81 if (_n == vstruct_last(i))
84 n = bkey_unpack_key(b, _n);
86 if (bpos_lt(n.p, k.k->p)) {
87 printk(KERN_ERR "Key skipped backwards\n");
91 if (!bkey_deleted(k.k) && bpos_eq(n.p, k.k->p))
92 printk(KERN_ERR "Duplicate keys\n");
98 void bch2_dump_btree_node(struct bch_fs *c, struct btree *b)
104 bch2_dump_bset(c, b, bset(b, t), t - b->set);
108 void bch2_dump_btree_node_iter(struct btree *b,
109 struct btree_node_iter *iter)
111 struct btree_node_iter_set *set;
112 struct printbuf buf = PRINTBUF;
114 printk(KERN_ERR "btree node iter with %u/%u sets:\n",
115 __btree_node_iter_used(iter), b->nsets);
117 btree_node_iter_for_each(iter, set) {
118 struct bkey_packed *k = __btree_node_offset_to_key(b, set->k);
119 struct bset_tree *t = bch2_bkey_to_bset(b, k);
120 struct bkey uk = bkey_unpack_key(b, k);
122 printbuf_reset(&buf);
123 bch2_bkey_to_text(&buf, &uk);
124 printk(KERN_ERR "set %zu key %u: %s\n",
125 t - b->set, set->k, buf.buf);
131 #ifdef CONFIG_BCACHEFS_DEBUG
133 void __bch2_verify_btree_nr_keys(struct btree *b)
136 struct bkey_packed *k;
137 struct btree_nr_keys nr = { 0 };
140 bset_tree_for_each_key(b, t, k)
141 if (!bkey_deleted(k))
142 btree_keys_account_key_add(&nr, t - b->set, k);
144 BUG_ON(memcmp(&nr, &b->nr, sizeof(nr)));
147 static void bch2_btree_node_iter_next_check(struct btree_node_iter *_iter,
150 struct btree_node_iter iter = *_iter;
151 const struct bkey_packed *k, *n;
153 k = bch2_btree_node_iter_peek_all(&iter, b);
154 __bch2_btree_node_iter_advance(&iter, b);
155 n = bch2_btree_node_iter_peek_all(&iter, b);
157 bkey_unpack_key(b, k);
160 bkey_iter_cmp(b, k, n) > 0) {
161 struct btree_node_iter_set *set;
162 struct bkey ku = bkey_unpack_key(b, k);
163 struct bkey nu = bkey_unpack_key(b, n);
164 struct printbuf buf1 = PRINTBUF;
165 struct printbuf buf2 = PRINTBUF;
167 bch2_dump_btree_node(NULL, b);
168 bch2_bkey_to_text(&buf1, &ku);
169 bch2_bkey_to_text(&buf2, &nu);
170 printk(KERN_ERR "out of order/overlapping:\n%s\n%s\n",
172 printk(KERN_ERR "iter was:");
174 btree_node_iter_for_each(_iter, set) {
175 struct bkey_packed *k = __btree_node_offset_to_key(b, set->k);
176 struct bset_tree *t = bch2_bkey_to_bset(b, k);
177 printk(" [%zi %zi]", t - b->set,
178 k->_data - bset(b, t)->_data);
184 void bch2_btree_node_iter_verify(struct btree_node_iter *iter,
187 struct btree_node_iter_set *set, *s2;
188 struct bkey_packed *k, *p;
191 if (bch2_btree_node_iter_end(iter))
194 /* Verify no duplicates: */
195 btree_node_iter_for_each(iter, set) {
196 BUG_ON(set->k > set->end);
197 btree_node_iter_for_each(iter, s2)
198 BUG_ON(set != s2 && set->end == s2->end);
201 /* Verify that set->end is correct: */
202 btree_node_iter_for_each(iter, set) {
204 if (set->end == t->end_offset)
208 BUG_ON(set->k < btree_bkey_first_offset(t) ||
209 set->k >= t->end_offset);
212 /* Verify iterator is sorted: */
213 btree_node_iter_for_each(iter, set)
214 BUG_ON(set != iter->data &&
215 btree_node_iter_cmp(b, set[-1], set[0]) > 0);
217 k = bch2_btree_node_iter_peek_all(iter, b);
219 for_each_bset(b, t) {
220 if (iter->data[0].end == t->end_offset)
223 p = bch2_bkey_prev_all(b, t,
224 bch2_btree_node_iter_bset_pos(iter, b, t));
226 BUG_ON(p && bkey_iter_cmp(b, k, p) < 0);
230 void bch2_verify_insert_pos(struct btree *b, struct bkey_packed *where,
231 struct bkey_packed *insert, unsigned clobber_u64s)
233 struct bset_tree *t = bch2_bkey_to_bset(b, where);
234 struct bkey_packed *prev = bch2_bkey_prev_all(b, t, where);
235 struct bkey_packed *next = (void *) (where->_data + clobber_u64s);
236 struct printbuf buf1 = PRINTBUF;
237 struct printbuf buf2 = PRINTBUF;
240 bkey_iter_cmp(b, prev, insert) > 0);
243 bkey_iter_cmp(b, prev, insert) > 0) {
244 struct bkey k1 = bkey_unpack_key(b, prev);
245 struct bkey k2 = bkey_unpack_key(b, insert);
247 bch2_dump_btree_node(NULL, b);
248 bch2_bkey_to_text(&buf1, &k1);
249 bch2_bkey_to_text(&buf2, &k2);
251 panic("prev > insert:\n"
258 BUG_ON(next != btree_bkey_last(b, t) &&
259 bkey_iter_cmp(b, insert, next) > 0);
261 if (next != btree_bkey_last(b, t) &&
262 bkey_iter_cmp(b, insert, next) > 0) {
263 struct bkey k1 = bkey_unpack_key(b, insert);
264 struct bkey k2 = bkey_unpack_key(b, next);
266 bch2_dump_btree_node(NULL, b);
267 bch2_bkey_to_text(&buf1, &k1);
268 bch2_bkey_to_text(&buf2, &k2);
270 panic("insert > next:\n"
280 static inline void bch2_btree_node_iter_next_check(struct btree_node_iter *iter,
285 /* Auxiliary search trees */
287 #define BFLOAT_FAILED_UNPACKED U8_MAX
288 #define BFLOAT_FAILED U8_MAX
295 #define BKEY_MANTISSA_BITS 16
297 static unsigned bkey_float_byte_offset(unsigned idx)
299 return idx * sizeof(struct bkey_float);
303 struct bkey_float f[0];
311 static unsigned bset_aux_tree_buf_end(const struct bset_tree *t)
313 BUG_ON(t->aux_data_offset == U16_MAX);
315 switch (bset_aux_tree_type(t)) {
316 case BSET_NO_AUX_TREE:
317 return t->aux_data_offset;
318 case BSET_RO_AUX_TREE:
319 return t->aux_data_offset +
320 DIV_ROUND_UP(t->size * sizeof(struct bkey_float) +
321 t->size * sizeof(u8), 8);
322 case BSET_RW_AUX_TREE:
323 return t->aux_data_offset +
324 DIV_ROUND_UP(sizeof(struct rw_aux_tree) * t->size, 8);
330 static unsigned bset_aux_tree_buf_start(const struct btree *b,
331 const struct bset_tree *t)
334 ? DIV_ROUND_UP(b->unpack_fn_len, 8)
335 : bset_aux_tree_buf_end(t - 1);
338 static void *__aux_tree_base(const struct btree *b,
339 const struct bset_tree *t)
341 return b->aux_data + t->aux_data_offset * 8;
344 static struct ro_aux_tree *ro_aux_tree_base(const struct btree *b,
345 const struct bset_tree *t)
347 EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
349 return __aux_tree_base(b, t);
352 static u8 *ro_aux_tree_prev(const struct btree *b,
353 const struct bset_tree *t)
355 EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
357 return __aux_tree_base(b, t) + bkey_float_byte_offset(t->size);
360 static struct bkey_float *bkey_float(const struct btree *b,
361 const struct bset_tree *t,
364 return ro_aux_tree_base(b, t)->f + idx;
367 static void bset_aux_tree_verify(const struct btree *b)
369 #ifdef CONFIG_BCACHEFS_DEBUG
370 const struct bset_tree *t;
372 for_each_bset(b, t) {
373 if (t->aux_data_offset == U16_MAX)
376 BUG_ON(t != b->set &&
377 t[-1].aux_data_offset == U16_MAX);
379 BUG_ON(t->aux_data_offset < bset_aux_tree_buf_start(b, t));
380 BUG_ON(t->aux_data_offset > btree_aux_data_u64s(b));
381 BUG_ON(bset_aux_tree_buf_end(t) > btree_aux_data_u64s(b));
386 void bch2_btree_keys_init(struct btree *b)
391 memset(&b->nr, 0, sizeof(b->nr));
393 for (i = 0; i < MAX_BSETS; i++)
394 b->set[i].data_offset = U16_MAX;
396 bch2_bset_set_no_aux_tree(b, b->set);
399 /* Binary tree stuff for auxiliary search trees */
402 * Cacheline/offset <-> bkey pointer arithmetic:
404 * t->tree is a binary search tree in an array; each node corresponds to a key
405 * in one cacheline in t->set (BSET_CACHELINE bytes).
407 * This means we don't have to store the full index of the key that a node in
408 * the binary tree points to; eytzinger1_to_inorder() gives us the cacheline, and
409 * then bkey_float->m gives us the offset within that cacheline, in units of 8
412 * cacheline_to_bkey() and friends abstract out all the pointer arithmetic to
415 * To construct the bfloat for an arbitrary key we need to know what the key
416 * immediately preceding it is: we have to check if the two keys differ in the
417 * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size
418 * of the previous key so we can walk backwards to it from t->tree[j]'s key.
421 static inline void *bset_cacheline(const struct btree *b,
422 const struct bset_tree *t,
425 return (void *) round_down((unsigned long) btree_bkey_first(b, t),
427 cacheline * BSET_CACHELINE;
430 static struct bkey_packed *cacheline_to_bkey(const struct btree *b,
431 const struct bset_tree *t,
435 return bset_cacheline(b, t, cacheline) + offset * 8;
438 static unsigned bkey_to_cacheline(const struct btree *b,
439 const struct bset_tree *t,
440 const struct bkey_packed *k)
442 return ((void *) k - bset_cacheline(b, t, 0)) / BSET_CACHELINE;
445 static ssize_t __bkey_to_cacheline_offset(const struct btree *b,
446 const struct bset_tree *t,
448 const struct bkey_packed *k)
450 return (u64 *) k - (u64 *) bset_cacheline(b, t, cacheline);
453 static unsigned bkey_to_cacheline_offset(const struct btree *b,
454 const struct bset_tree *t,
456 const struct bkey_packed *k)
458 size_t m = __bkey_to_cacheline_offset(b, t, cacheline, k);
464 static inline struct bkey_packed *tree_to_bkey(const struct btree *b,
465 const struct bset_tree *t,
468 return cacheline_to_bkey(b, t,
469 __eytzinger1_to_inorder(j, t->size - 1, t->extra),
470 bkey_float(b, t, j)->key_offset);
473 static struct bkey_packed *tree_to_prev_bkey(const struct btree *b,
474 const struct bset_tree *t,
477 unsigned prev_u64s = ro_aux_tree_prev(b, t)[j];
479 return (void *) (tree_to_bkey(b, t, j)->_data - prev_u64s);
482 static struct rw_aux_tree *rw_aux_tree(const struct btree *b,
483 const struct bset_tree *t)
485 EBUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);
487 return __aux_tree_base(b, t);
491 * For the write set - the one we're currently inserting keys into - we don't
492 * maintain a full search tree, we just keep a simple lookup table in t->prev.
494 static struct bkey_packed *rw_aux_to_bkey(const struct btree *b,
498 return __btree_node_offset_to_key(b, rw_aux_tree(b, t)[j].offset);
501 static void rw_aux_tree_set(const struct btree *b, struct bset_tree *t,
502 unsigned j, struct bkey_packed *k)
504 EBUG_ON(k >= btree_bkey_last(b, t));
506 rw_aux_tree(b, t)[j] = (struct rw_aux_tree) {
507 .offset = __btree_node_key_to_offset(b, k),
508 .k = bkey_unpack_pos(b, k),
512 static void bch2_bset_verify_rw_aux_tree(struct btree *b,
515 struct bkey_packed *k = btree_bkey_first(b, t);
518 if (!bch2_expensive_debug_checks)
521 BUG_ON(bset_has_ro_aux_tree(t));
523 if (!bset_has_rw_aux_tree(t))
527 BUG_ON(rw_aux_to_bkey(b, t, j) != k);
531 if (rw_aux_to_bkey(b, t, j) == k) {
532 BUG_ON(!bpos_eq(rw_aux_tree(b, t)[j].k,
533 bkey_unpack_pos(b, k)));
538 BUG_ON(rw_aux_tree(b, t)[j].offset <=
539 rw_aux_tree(b, t)[j - 1].offset);
543 BUG_ON(k >= btree_bkey_last(b, t));
547 /* returns idx of first entry >= offset: */
548 static unsigned rw_aux_tree_bsearch(struct btree *b,
552 unsigned bset_offs = offset - btree_bkey_first_offset(t);
553 unsigned bset_u64s = t->end_offset - btree_bkey_first_offset(t);
554 unsigned idx = bset_u64s ? bset_offs * t->size / bset_u64s : 0;
556 EBUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);
558 EBUG_ON(idx > t->size);
560 while (idx < t->size &&
561 rw_aux_tree(b, t)[idx].offset < offset)
565 rw_aux_tree(b, t)[idx - 1].offset >= offset)
568 EBUG_ON(idx < t->size &&
569 rw_aux_tree(b, t)[idx].offset < offset);
570 EBUG_ON(idx && rw_aux_tree(b, t)[idx - 1].offset >= offset);
571 EBUG_ON(idx + 1 < t->size &&
572 rw_aux_tree(b, t)[idx].offset ==
573 rw_aux_tree(b, t)[idx + 1].offset);
578 static inline unsigned bkey_mantissa(const struct bkey_packed *k,
579 const struct bkey_float *f,
584 EBUG_ON(!bkey_packed(k));
586 v = get_unaligned((u64 *) (((u8 *) k->_data) + (f->exponent >> 3)));
589 * In little endian, we're shifting off low bits (and then the bits we
590 * want are at the low end), in big endian we're shifting off high bits
591 * (and then the bits we want are at the high end, so we shift them
594 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
595 v >>= f->exponent & 7;
597 v >>= 64 - (f->exponent & 7) - BKEY_MANTISSA_BITS;
603 static inline void make_bfloat(struct btree *b, struct bset_tree *t,
605 struct bkey_packed *min_key,
606 struct bkey_packed *max_key)
608 struct bkey_float *f = bkey_float(b, t, j);
609 struct bkey_packed *m = tree_to_bkey(b, t, j);
610 struct bkey_packed *l = is_power_of_2(j)
612 : tree_to_prev_bkey(b, t, j >> ffs(j));
613 struct bkey_packed *r = is_power_of_2(j + 1)
615 : tree_to_bkey(b, t, j >> (ffz(j) + 1));
617 int shift, exponent, high_bit;
620 * for failed bfloats, the lookup code falls back to comparing against
624 if (!bkey_packed(l) || !bkey_packed(r) || !bkey_packed(m) ||
626 f->exponent = BFLOAT_FAILED_UNPACKED;
631 * The greatest differing bit of l and r is the first bit we must
632 * include in the bfloat mantissa we're creating in order to do
633 * comparisons - that bit always becomes the high bit of
634 * bfloat->mantissa, and thus the exponent we're calculating here is
635 * the position of what will become the low bit in bfloat->mantissa:
637 * Note that this may be negative - we may be running off the low end
638 * of the key: we handle this later:
640 high_bit = max(bch2_bkey_greatest_differing_bit(b, l, r),
641 min_t(unsigned, BKEY_MANTISSA_BITS, b->nr_key_bits) - 1);
642 exponent = high_bit - (BKEY_MANTISSA_BITS - 1);
645 * Then we calculate the actual shift value, from the start of the key
646 * (k->_data), to get the key bits starting at exponent:
648 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
649 shift = (int) (b->format.key_u64s * 64 - b->nr_key_bits) + exponent;
651 EBUG_ON(shift + BKEY_MANTISSA_BITS > b->format.key_u64s * 64);
653 shift = high_bit_offset +
658 EBUG_ON(shift < KEY_PACKED_BITS_START);
660 EBUG_ON(shift < 0 || shift >= BFLOAT_FAILED);
663 mantissa = bkey_mantissa(m, f, j);
666 * If we've got garbage bits, set them to all 1s - it's legal for the
667 * bfloat to compare larger than the original key, but not smaller:
670 mantissa |= ~(~0U << -exponent);
672 f->mantissa = mantissa;
675 /* bytes remaining - only valid for last bset: */
676 static unsigned __bset_tree_capacity(const struct btree *b, const struct bset_tree *t)
678 bset_aux_tree_verify(b);
680 return btree_aux_data_bytes(b) - t->aux_data_offset * sizeof(u64);
683 static unsigned bset_ro_tree_capacity(const struct btree *b, const struct bset_tree *t)
685 return __bset_tree_capacity(b, t) /
686 (sizeof(struct bkey_float) + sizeof(u8));
689 static unsigned bset_rw_tree_capacity(const struct btree *b, const struct bset_tree *t)
691 return __bset_tree_capacity(b, t) / sizeof(struct rw_aux_tree);
694 static noinline void __build_rw_aux_tree(struct btree *b, struct bset_tree *t)
696 struct bkey_packed *k;
699 t->extra = BSET_RW_AUX_TREE_VAL;
700 rw_aux_tree(b, t)[0].offset =
701 __btree_node_key_to_offset(b, btree_bkey_first(b, t));
703 bset_tree_for_each_key(b, t, k) {
704 if (t->size == bset_rw_tree_capacity(b, t))
707 if ((void *) k - (void *) rw_aux_to_bkey(b, t, t->size - 1) >
709 rw_aux_tree_set(b, t, t->size++, k);
713 static noinline void __build_ro_aux_tree(struct btree *b, struct bset_tree *t)
715 struct bkey_packed *prev = NULL, *k = btree_bkey_first(b, t);
716 struct bkey_i min_key, max_key;
717 unsigned j, cacheline = 1;
719 t->size = min(bkey_to_cacheline(b, t, btree_bkey_last(b, t)),
720 bset_ro_tree_capacity(b, t));
724 t->extra = BSET_NO_AUX_TREE_VAL;
728 t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1;
730 /* First we figure out where the first key in each cacheline is */
731 eytzinger1_for_each(j, t->size - 1) {
732 while (bkey_to_cacheline(b, t, k) < cacheline)
733 prev = k, k = bkey_p_next(k);
735 if (k >= btree_bkey_last(b, t)) {
736 /* XXX: this path sucks */
741 ro_aux_tree_prev(b, t)[j] = prev->u64s;
742 bkey_float(b, t, j)->key_offset =
743 bkey_to_cacheline_offset(b, t, cacheline++, k);
745 EBUG_ON(tree_to_prev_bkey(b, t, j) != prev);
746 EBUG_ON(tree_to_bkey(b, t, j) != k);
749 while (k != btree_bkey_last(b, t))
750 prev = k, k = bkey_p_next(k);
752 if (!bkey_pack_pos(bkey_to_packed(&min_key), b->data->min_key, b)) {
753 bkey_init(&min_key.k);
754 min_key.k.p = b->data->min_key;
757 if (!bkey_pack_pos(bkey_to_packed(&max_key), b->data->max_key, b)) {
758 bkey_init(&max_key.k);
759 max_key.k.p = b->data->max_key;
762 /* Then we build the tree */
763 eytzinger1_for_each(j, t->size - 1)
765 bkey_to_packed(&min_key),
766 bkey_to_packed(&max_key));
769 static void bset_alloc_tree(struct btree *b, struct bset_tree *t)
773 for (i = b->set; i != t; i++)
774 BUG_ON(bset_has_rw_aux_tree(i));
776 bch2_bset_set_no_aux_tree(b, t);
778 /* round up to next cacheline: */
779 t->aux_data_offset = round_up(bset_aux_tree_buf_start(b, t),
780 SMP_CACHE_BYTES / sizeof(u64));
782 bset_aux_tree_verify(b);
785 void bch2_bset_build_aux_tree(struct btree *b, struct bset_tree *t,
789 ? bset_has_rw_aux_tree(t)
790 : bset_has_ro_aux_tree(t))
793 bset_alloc_tree(b, t);
795 if (!__bset_tree_capacity(b, t))
799 __build_rw_aux_tree(b, t);
801 __build_ro_aux_tree(b, t);
803 bset_aux_tree_verify(b);
806 void bch2_bset_init_first(struct btree *b, struct bset *i)
812 memset(i, 0, sizeof(*i));
813 get_random_bytes(&i->seq, sizeof(i->seq));
814 SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);
816 t = &b->set[b->nsets++];
817 set_btree_bset(b, t, i);
820 void bch2_bset_init_next(struct bch_fs *c, struct btree *b,
821 struct btree_node_entry *bne)
823 struct bset *i = &bne->keys;
826 BUG_ON(bset_byte_offset(b, bne) >= btree_bytes(c));
827 BUG_ON((void *) bne < (void *) btree_bkey_last(b, bset_tree_last(b)));
828 BUG_ON(b->nsets >= MAX_BSETS);
830 memset(i, 0, sizeof(*i));
831 i->seq = btree_bset_first(b)->seq;
832 SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);
834 t = &b->set[b->nsets++];
835 set_btree_bset(b, t, i);
839 * find _some_ key in the same bset as @k that precedes @k - not necessarily the
840 * immediate predecessor:
842 static struct bkey_packed *__bkey_prev(struct btree *b, struct bset_tree *t,
843 struct bkey_packed *k)
845 struct bkey_packed *p;
849 EBUG_ON(k < btree_bkey_first(b, t) ||
850 k > btree_bkey_last(b, t));
852 if (k == btree_bkey_first(b, t))
855 switch (bset_aux_tree_type(t)) {
856 case BSET_NO_AUX_TREE:
857 p = btree_bkey_first(b, t);
859 case BSET_RO_AUX_TREE:
860 j = min_t(unsigned, t->size - 1, bkey_to_cacheline(b, t, k));
863 p = j ? tree_to_bkey(b, t,
864 __inorder_to_eytzinger1(j--,
865 t->size - 1, t->extra))
866 : btree_bkey_first(b, t);
869 case BSET_RW_AUX_TREE:
870 offset = __btree_node_key_to_offset(b, k);
871 j = rw_aux_tree_bsearch(b, t, offset);
872 p = j ? rw_aux_to_bkey(b, t, j - 1)
873 : btree_bkey_first(b, t);
880 struct bkey_packed *bch2_bkey_prev_filter(struct btree *b,
882 struct bkey_packed *k,
883 unsigned min_key_type)
885 struct bkey_packed *p, *i, *ret = NULL, *orig_k = k;
887 while ((p = __bkey_prev(b, t, k)) && !ret) {
888 for (i = p; i != k; i = bkey_p_next(i))
889 if (i->type >= min_key_type)
895 if (bch2_expensive_debug_checks) {
896 BUG_ON(ret >= orig_k);
900 : btree_bkey_first(b, t);
903 BUG_ON(i->type >= min_key_type);
911 static void bch2_bset_fix_lookup_table(struct btree *b,
913 struct bkey_packed *_where,
914 unsigned clobber_u64s,
917 int shift = new_u64s - clobber_u64s;
918 unsigned l, j, where = __btree_node_key_to_offset(b, _where);
920 EBUG_ON(bset_has_ro_aux_tree(t));
922 if (!bset_has_rw_aux_tree(t))
925 /* returns first entry >= where */
926 l = rw_aux_tree_bsearch(b, t, where);
928 if (!l) /* never delete first entry */
930 else if (l < t->size &&
931 where < t->end_offset &&
932 rw_aux_tree(b, t)[l].offset == where)
933 rw_aux_tree_set(b, t, l++, _where);
939 rw_aux_tree(b, t)[j].offset < where + clobber_u64s;
944 rw_aux_tree(b, t)[j].offset + shift ==
945 rw_aux_tree(b, t)[l - 1].offset)
948 memmove(&rw_aux_tree(b, t)[l],
949 &rw_aux_tree(b, t)[j],
950 (void *) &rw_aux_tree(b, t)[t->size] -
951 (void *) &rw_aux_tree(b, t)[j]);
954 for (j = l; j < t->size; j++)
955 rw_aux_tree(b, t)[j].offset += shift;
957 EBUG_ON(l < t->size &&
958 rw_aux_tree(b, t)[l].offset ==
959 rw_aux_tree(b, t)[l - 1].offset);
961 if (t->size < bset_rw_tree_capacity(b, t) &&
963 ? rw_aux_tree(b, t)[l].offset
965 rw_aux_tree(b, t)[l - 1].offset >
966 L1_CACHE_BYTES / sizeof(u64)) {
967 struct bkey_packed *start = rw_aux_to_bkey(b, t, l - 1);
968 struct bkey_packed *end = l < t->size
969 ? rw_aux_to_bkey(b, t, l)
970 : btree_bkey_last(b, t);
971 struct bkey_packed *k = start;
978 if ((void *) k - (void *) start >= L1_CACHE_BYTES) {
979 memmove(&rw_aux_tree(b, t)[l + 1],
980 &rw_aux_tree(b, t)[l],
981 (void *) &rw_aux_tree(b, t)[t->size] -
982 (void *) &rw_aux_tree(b, t)[l]);
984 rw_aux_tree_set(b, t, l, k);
990 bch2_bset_verify_rw_aux_tree(b, t);
991 bset_aux_tree_verify(b);
994 void bch2_bset_insert(struct btree *b,
995 struct btree_node_iter *iter,
996 struct bkey_packed *where,
997 struct bkey_i *insert,
998 unsigned clobber_u64s)
1000 struct bkey_format *f = &b->format;
1001 struct bset_tree *t = bset_tree_last(b);
1002 struct bkey_packed packed, *src = bkey_to_packed(insert);
1004 bch2_bset_verify_rw_aux_tree(b, t);
1005 bch2_verify_insert_pos(b, where, bkey_to_packed(insert), clobber_u64s);
1007 if (bch2_bkey_pack_key(&packed, &insert->k, f))
1010 if (!bkey_deleted(&insert->k))
1011 btree_keys_account_key_add(&b->nr, t - b->set, src);
1013 if (src->u64s != clobber_u64s) {
1014 u64 *src_p = where->_data + clobber_u64s;
1015 u64 *dst_p = where->_data + src->u64s;
1017 EBUG_ON((int) le16_to_cpu(bset(b, t)->u64s) <
1018 (int) clobber_u64s - src->u64s);
1020 memmove_u64s(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);
1021 le16_add_cpu(&bset(b, t)->u64s, src->u64s - clobber_u64s);
1022 set_btree_bset_end(b, t);
1025 memcpy_u64s_small(where, src,
1026 bkeyp_key_u64s(f, src));
1027 memcpy_u64s(bkeyp_val(f, where), &insert->v,
1028 bkeyp_val_u64s(f, src));
1030 if (src->u64s != clobber_u64s)
1031 bch2_bset_fix_lookup_table(b, t, where, clobber_u64s, src->u64s);
1033 bch2_verify_btree_nr_keys(b);
1036 void bch2_bset_delete(struct btree *b,
1037 struct bkey_packed *where,
1038 unsigned clobber_u64s)
1040 struct bset_tree *t = bset_tree_last(b);
1041 u64 *src_p = where->_data + clobber_u64s;
1042 u64 *dst_p = where->_data;
1044 bch2_bset_verify_rw_aux_tree(b, t);
1046 EBUG_ON(le16_to_cpu(bset(b, t)->u64s) < clobber_u64s);
1048 memmove_u64s_down(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);
1049 le16_add_cpu(&bset(b, t)->u64s, -clobber_u64s);
1050 set_btree_bset_end(b, t);
1052 bch2_bset_fix_lookup_table(b, t, where, clobber_u64s, 0);
1058 static struct bkey_packed *bset_search_write_set(const struct btree *b,
1059 struct bset_tree *t,
1060 struct bpos *search)
1062 unsigned l = 0, r = t->size;
1064 while (l + 1 != r) {
1065 unsigned m = (l + r) >> 1;
1067 if (bpos_lt(rw_aux_tree(b, t)[m].k, *search))
1073 return rw_aux_to_bkey(b, t, l);
1076 static inline void prefetch_four_cachelines(void *p)
1078 #ifdef CONFIG_X86_64
1079 asm("prefetcht0 (-127 + 64 * 0)(%0);"
1080 "prefetcht0 (-127 + 64 * 1)(%0);"
1081 "prefetcht0 (-127 + 64 * 2)(%0);"
1082 "prefetcht0 (-127 + 64 * 3)(%0);"
1086 prefetch(p + L1_CACHE_BYTES * 0);
1087 prefetch(p + L1_CACHE_BYTES * 1);
1088 prefetch(p + L1_CACHE_BYTES * 2);
1089 prefetch(p + L1_CACHE_BYTES * 3);
1093 static inline bool bkey_mantissa_bits_dropped(const struct btree *b,
1094 const struct bkey_float *f,
1097 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
1098 unsigned key_bits_start = b->format.key_u64s * 64 - b->nr_key_bits;
1100 return f->exponent > key_bits_start;
1102 unsigned key_bits_end = high_bit_offset + b->nr_key_bits;
1104 return f->exponent + BKEY_MANTISSA_BITS < key_bits_end;
1109 static struct bkey_packed *bset_search_tree(const struct btree *b,
1110 const struct bset_tree *t,
1111 const struct bpos *search,
1112 const struct bkey_packed *packed_search)
1114 struct ro_aux_tree *base = ro_aux_tree_base(b, t);
1115 struct bkey_float *f;
1116 struct bkey_packed *k;
1117 unsigned inorder, n = 1, l, r;
1121 if (likely(n << 4 < t->size))
1122 prefetch(&base->f[n << 4]);
1125 if (unlikely(f->exponent >= BFLOAT_FAILED))
1129 r = bkey_mantissa(packed_search, f, n);
1131 if (unlikely(l == r) && bkey_mantissa_bits_dropped(b, f, n))
1134 n = n * 2 + (l < r);
1137 k = tree_to_bkey(b, t, n);
1138 cmp = bkey_cmp_p_or_unp(b, k, packed_search, search);
1142 n = n * 2 + (cmp < 0);
1143 } while (n < t->size);
1145 inorder = __eytzinger1_to_inorder(n >> 1, t->size - 1, t->extra);
1148 * n would have been the node we recursed to - the low bit tells us if
1149 * we recursed left or recursed right.
1151 if (likely(!(n & 1))) {
1153 if (unlikely(!inorder))
1154 return btree_bkey_first(b, t);
1156 f = &base->f[eytzinger1_prev(n >> 1, t->size - 1)];
1159 return cacheline_to_bkey(b, t, inorder, f->key_offset);
1162 static __always_inline __flatten
1163 struct bkey_packed *__bch2_bset_search(struct btree *b,
1164 struct bset_tree *t,
1165 struct bpos *search,
1166 const struct bkey_packed *lossy_packed_search)
1170 * First, we search for a cacheline, then lastly we do a linear search
1171 * within that cacheline.
1173 * To search for the cacheline, there's three different possibilities:
1174 * * The set is too small to have a search tree, so we just do a linear
1175 * search over the whole set.
1176 * * The set is the one we're currently inserting into; keeping a full
1177 * auxiliary search tree up to date would be too expensive, so we
1178 * use a much simpler lookup table to do a binary search -
1179 * bset_search_write_set().
1180 * * Or we use the auxiliary search tree we constructed earlier -
1181 * bset_search_tree()
1184 switch (bset_aux_tree_type(t)) {
1185 case BSET_NO_AUX_TREE:
1186 return btree_bkey_first(b, t);
1187 case BSET_RW_AUX_TREE:
1188 return bset_search_write_set(b, t, search);
1189 case BSET_RO_AUX_TREE:
1190 return bset_search_tree(b, t, search, lossy_packed_search);
1196 static __always_inline __flatten
1197 struct bkey_packed *bch2_bset_search_linear(struct btree *b,
1198 struct bset_tree *t,
1199 struct bpos *search,
1200 struct bkey_packed *packed_search,
1201 const struct bkey_packed *lossy_packed_search,
1202 struct bkey_packed *m)
1204 if (lossy_packed_search)
1205 while (m != btree_bkey_last(b, t) &&
1206 bkey_iter_cmp_p_or_unp(b, m,
1207 lossy_packed_search, search) < 0)
1211 while (m != btree_bkey_last(b, t) &&
1212 bkey_iter_pos_cmp(b, m, search) < 0)
1215 if (bch2_expensive_debug_checks) {
1216 struct bkey_packed *prev = bch2_bkey_prev_all(b, t, m);
1219 bkey_iter_cmp_p_or_unp(b, prev,
1220 packed_search, search) >= 0);
1226 /* Btree node iterator */
1228 static inline void __bch2_btree_node_iter_push(struct btree_node_iter *iter,
1230 const struct bkey_packed *k,
1231 const struct bkey_packed *end)
1234 struct btree_node_iter_set *pos;
1236 btree_node_iter_for_each(iter, pos)
1239 BUG_ON(pos >= iter->data + ARRAY_SIZE(iter->data));
1240 *pos = (struct btree_node_iter_set) {
1241 __btree_node_key_to_offset(b, k),
1242 __btree_node_key_to_offset(b, end)
1247 void bch2_btree_node_iter_push(struct btree_node_iter *iter,
1249 const struct bkey_packed *k,
1250 const struct bkey_packed *end)
1252 __bch2_btree_node_iter_push(iter, b, k, end);
1253 bch2_btree_node_iter_sort(iter, b);
1256 noinline __flatten __cold
1257 static void btree_node_iter_init_pack_failed(struct btree_node_iter *iter,
1258 struct btree *b, struct bpos *search)
1260 struct bkey_packed *k;
1262 trace_bkey_pack_pos_fail(search);
1264 bch2_btree_node_iter_init_from_start(iter, b);
1266 while ((k = bch2_btree_node_iter_peek(iter, b)) &&
1267 bkey_iter_pos_cmp(b, k, search) < 0)
1268 bch2_btree_node_iter_advance(iter, b);
1272 * bch_btree_node_iter_init - initialize a btree node iterator, starting from a
1275 * Main entry point to the lookup code for individual btree nodes:
1279 * When you don't filter out deleted keys, btree nodes _do_ contain duplicate
1280 * keys. This doesn't matter for most code, but it does matter for lookups.
1282 * Some adjacent keys with a string of equal keys:
1285 * If you search for k, the lookup code isn't guaranteed to return you any
1286 * specific k. The lookup code is conceptually doing a binary search and
1287 * iterating backwards is very expensive so if the pivot happens to land at the
1288 * last k that's what you'll get.
1290 * This works out ok, but it's something to be aware of:
1292 * - For non extents, we guarantee that the live key comes last - see
1293 * btree_node_iter_cmp(), keys_out_of_order(). So the duplicates you don't
1294 * see will only be deleted keys you don't care about.
1296 * - For extents, deleted keys sort last (see the comment at the top of this
1297 * file). But when you're searching for extents, you actually want the first
1298 * key strictly greater than your search key - an extent that compares equal
1299 * to the search key is going to have 0 sectors after the search key.
1301 * But this does mean that we can't just search for
1302 * bpos_successor(start_of_range) to get the first extent that overlaps with
1303 * the range we want - if we're unlucky and there's an extent that ends
1304 * exactly where we searched, then there could be a deleted key at the same
1305 * position and we'd get that when we search instead of the preceding extent
1308 * So we've got to search for start_of_range, then after the lookup iterate
1309 * past any extents that compare equal to the position we searched for.
1312 void bch2_btree_node_iter_init(struct btree_node_iter *iter,
1313 struct btree *b, struct bpos *search)
1315 struct bkey_packed p, *packed_search = NULL;
1316 struct btree_node_iter_set *pos = iter->data;
1317 struct bkey_packed *k[MAX_BSETS];
1320 EBUG_ON(bpos_lt(*search, b->data->min_key));
1321 EBUG_ON(bpos_gt(*search, b->data->max_key));
1322 bset_aux_tree_verify(b);
1324 memset(iter, 0, sizeof(*iter));
1326 switch (bch2_bkey_pack_pos_lossy(&p, *search, b)) {
1327 case BKEY_PACK_POS_EXACT:
1330 case BKEY_PACK_POS_SMALLER:
1331 packed_search = NULL;
1333 case BKEY_PACK_POS_FAIL:
1334 btree_node_iter_init_pack_failed(iter, b, search);
1338 for (i = 0; i < b->nsets; i++) {
1339 k[i] = __bch2_bset_search(b, b->set + i, search, &p);
1340 prefetch_four_cachelines(k[i]);
1343 for (i = 0; i < b->nsets; i++) {
1344 struct bset_tree *t = b->set + i;
1345 struct bkey_packed *end = btree_bkey_last(b, t);
1347 k[i] = bch2_bset_search_linear(b, t, search,
1348 packed_search, &p, k[i]);
1350 *pos++ = (struct btree_node_iter_set) {
1351 __btree_node_key_to_offset(b, k[i]),
1352 __btree_node_key_to_offset(b, end)
1356 bch2_btree_node_iter_sort(iter, b);
1359 void bch2_btree_node_iter_init_from_start(struct btree_node_iter *iter,
1362 struct bset_tree *t;
1364 memset(iter, 0, sizeof(*iter));
1367 __bch2_btree_node_iter_push(iter, b,
1368 btree_bkey_first(b, t),
1369 btree_bkey_last(b, t));
1370 bch2_btree_node_iter_sort(iter, b);
1373 struct bkey_packed *bch2_btree_node_iter_bset_pos(struct btree_node_iter *iter,
1375 struct bset_tree *t)
1377 struct btree_node_iter_set *set;
1379 btree_node_iter_for_each(iter, set)
1380 if (set->end == t->end_offset)
1381 return __btree_node_offset_to_key(b, set->k);
1383 return btree_bkey_last(b, t);
1386 static inline bool btree_node_iter_sort_two(struct btree_node_iter *iter,
1392 if ((ret = (btree_node_iter_cmp(b,
1394 iter->data[first + 1]) > 0)))
1395 swap(iter->data[first], iter->data[first + 1]);
1399 void bch2_btree_node_iter_sort(struct btree_node_iter *iter,
1402 /* unrolled bubble sort: */
1404 if (!__btree_node_iter_set_end(iter, 2)) {
1405 btree_node_iter_sort_two(iter, b, 0);
1406 btree_node_iter_sort_two(iter, b, 1);
1409 if (!__btree_node_iter_set_end(iter, 1))
1410 btree_node_iter_sort_two(iter, b, 0);
1413 void bch2_btree_node_iter_set_drop(struct btree_node_iter *iter,
1414 struct btree_node_iter_set *set)
1416 struct btree_node_iter_set *last =
1417 iter->data + ARRAY_SIZE(iter->data) - 1;
1419 memmove(&set[0], &set[1], (void *) last - (void *) set);
1420 *last = (struct btree_node_iter_set) { 0, 0 };
1423 static inline void __bch2_btree_node_iter_advance(struct btree_node_iter *iter,
1426 iter->data->k += __bch2_btree_node_iter_peek_all(iter, b)->u64s;
1428 EBUG_ON(iter->data->k > iter->data->end);
1430 if (unlikely(__btree_node_iter_set_end(iter, 0))) {
1431 /* avoid an expensive memmove call: */
1432 iter->data[0] = iter->data[1];
1433 iter->data[1] = iter->data[2];
1434 iter->data[2] = (struct btree_node_iter_set) { 0, 0 };
1438 if (__btree_node_iter_set_end(iter, 1))
1441 if (!btree_node_iter_sort_two(iter, b, 0))
1444 if (__btree_node_iter_set_end(iter, 2))
1447 btree_node_iter_sort_two(iter, b, 1);
1450 void bch2_btree_node_iter_advance(struct btree_node_iter *iter,
1453 if (bch2_expensive_debug_checks) {
1454 bch2_btree_node_iter_verify(iter, b);
1455 bch2_btree_node_iter_next_check(iter, b);
1458 __bch2_btree_node_iter_advance(iter, b);
1464 struct bkey_packed *bch2_btree_node_iter_prev_all(struct btree_node_iter *iter,
1467 struct bkey_packed *k, *prev = NULL;
1468 struct btree_node_iter_set *set;
1469 struct bset_tree *t;
1472 if (bch2_expensive_debug_checks)
1473 bch2_btree_node_iter_verify(iter, b);
1475 for_each_bset(b, t) {
1476 k = bch2_bkey_prev_all(b, t,
1477 bch2_btree_node_iter_bset_pos(iter, b, t));
1479 (!prev || bkey_iter_cmp(b, k, prev) > 0)) {
1481 end = t->end_offset;
1489 * We're manually memmoving instead of just calling sort() to ensure the
1490 * prev we picked ends up in slot 0 - sort won't necessarily put it
1491 * there because of duplicate deleted keys:
1493 btree_node_iter_for_each(iter, set)
1494 if (set->end == end)
1497 BUG_ON(set != &iter->data[__btree_node_iter_used(iter)]);
1499 BUG_ON(set >= iter->data + ARRAY_SIZE(iter->data));
1501 memmove(&iter->data[1],
1503 (void *) set - (void *) &iter->data[0]);
1505 iter->data[0].k = __btree_node_key_to_offset(b, prev);
1506 iter->data[0].end = end;
1508 if (bch2_expensive_debug_checks)
1509 bch2_btree_node_iter_verify(iter, b);
1513 struct bkey_packed *bch2_btree_node_iter_prev(struct btree_node_iter *iter,
1516 struct bkey_packed *prev;
1519 prev = bch2_btree_node_iter_prev_all(iter, b);
1520 } while (prev && bkey_deleted(prev));
1525 struct bkey_s_c bch2_btree_node_iter_peek_unpack(struct btree_node_iter *iter,
1529 struct bkey_packed *k = bch2_btree_node_iter_peek(iter, b);
1531 return k ? bkey_disassemble(b, k, u) : bkey_s_c_null;
1536 void bch2_btree_keys_stats(const struct btree *b, struct bset_stats *stats)
1538 const struct bset_tree *t;
1540 for_each_bset(b, t) {
1541 enum bset_aux_tree_type type = bset_aux_tree_type(t);
1544 stats->sets[type].nr++;
1545 stats->sets[type].bytes += le16_to_cpu(bset(b, t)->u64s) *
1548 if (bset_has_ro_aux_tree(t)) {
1549 stats->floats += t->size - 1;
1551 for (j = 1; j < t->size; j++)
1553 bkey_float(b, t, j)->exponent ==
1559 void bch2_bfloat_to_text(struct printbuf *out, struct btree *b,
1560 struct bkey_packed *k)
1562 struct bset_tree *t = bch2_bkey_to_bset(b, k);
1564 unsigned j, inorder;
1566 if (!bset_has_ro_aux_tree(t))
1569 inorder = bkey_to_cacheline(b, t, k);
1570 if (!inorder || inorder >= t->size)
1573 j = __inorder_to_eytzinger1(inorder, t->size - 1, t->extra);
1574 if (k != tree_to_bkey(b, t, j))
1577 switch (bkey_float(b, t, j)->exponent) {
1579 uk = bkey_unpack_key(b, k);
1581 " failed unpacked at depth %u\n"
1584 bch2_bpos_to_text(out, uk.p);
1585 prt_printf(out, "\n");