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1// SPDX-License-Identifier: GPL-2.02/*3 * Code for working with individual keys, and sorted sets of keys with in a4 * btree node5 *6 * Copyright 2012 Google, Inc.7 */8 9#include "bcachefs.h"10#include "btree_cache.h"11#include "bset.h"12#include "eytzinger.h"13#include "trace.h"14#include "util.h"15 16#include <linux/unaligned.h>17#include <linux/console.h>18#include <linux/random.h>19#include <linux/prefetch.h>20 21static inline void __bch2_btree_node_iter_advance(struct btree_node_iter *,22						  struct btree *);23 24static inline unsigned __btree_node_iter_used(struct btree_node_iter *iter)25{26	unsigned n = ARRAY_SIZE(iter->data);27 28	while (n && __btree_node_iter_set_end(iter, n - 1))29		--n;30 31	return n;32}33 34struct bset_tree *bch2_bkey_to_bset(struct btree *b, struct bkey_packed *k)35{36	return bch2_bkey_to_bset_inlined(b, k);37}38 39/*40 * There are never duplicate live keys in the btree - but including keys that41 * have been flagged as deleted (and will be cleaned up later) we _will_ see42 * duplicates.43 *44 * Thus the sort order is: usual key comparison first, but for keys that compare45 * equal the deleted key(s) come first, and the (at most one) live version comes46 * last.47 *48 * The main reason for this is insertion: to handle overwrites, we first iterate49 * over keys that compare equal to our insert key, and then insert immediately50 * prior to the first key greater than the key we're inserting - our insert51 * position will be after all keys that compare equal to our insert key, which52 * by the time we actually do the insert will all be deleted.53 */54 55void bch2_dump_bset(struct bch_fs *c, struct btree *b,56		    struct bset *i, unsigned set)57{58	struct bkey_packed *_k, *_n;59	struct bkey uk, n;60	struct bkey_s_c k;61	struct printbuf buf = PRINTBUF;62 63	if (!i->u64s)64		return;65 66	for (_k = i->start;67	     _k < vstruct_last(i);68	     _k = _n) {69		_n = bkey_p_next(_k);70 71		if (!_k->u64s) {72			printk(KERN_ERR "block %u key %5zu - u64s 0? aieee!\n", set,73			       _k->_data - i->_data);74			break;75		}76 77		k = bkey_disassemble(b, _k, &uk);78 79		printbuf_reset(&buf);80		if (c)81			bch2_bkey_val_to_text(&buf, c, k);82		else83			bch2_bkey_to_text(&buf, k.k);84		printk(KERN_ERR "block %u key %5zu: %s\n", set,85		       _k->_data - i->_data, buf.buf);86 87		if (_n == vstruct_last(i))88			continue;89 90		n = bkey_unpack_key(b, _n);91 92		if (bpos_lt(n.p, k.k->p)) {93			printk(KERN_ERR "Key skipped backwards\n");94			continue;95		}96 97		if (!bkey_deleted(k.k) && bpos_eq(n.p, k.k->p))98			printk(KERN_ERR "Duplicate keys\n");99	}100 101	printbuf_exit(&buf);102}103 104void bch2_dump_btree_node(struct bch_fs *c, struct btree *b)105{106	console_lock();107	for_each_bset(b, t)108		bch2_dump_bset(c, b, bset(b, t), t - b->set);109	console_unlock();110}111 112void bch2_dump_btree_node_iter(struct btree *b,113			      struct btree_node_iter *iter)114{115	struct btree_node_iter_set *set;116	struct printbuf buf = PRINTBUF;117 118	printk(KERN_ERR "btree node iter with %u/%u sets:\n",119	       __btree_node_iter_used(iter), b->nsets);120 121	btree_node_iter_for_each(iter, set) {122		struct bkey_packed *k = __btree_node_offset_to_key(b, set->k);123		struct bset_tree *t = bch2_bkey_to_bset(b, k);124		struct bkey uk = bkey_unpack_key(b, k);125 126		printbuf_reset(&buf);127		bch2_bkey_to_text(&buf, &uk);128		printk(KERN_ERR "set %zu key %u: %s\n",129		       t - b->set, set->k, buf.buf);130	}131 132	printbuf_exit(&buf);133}134 135struct btree_nr_keys bch2_btree_node_count_keys(struct btree *b)136{137	struct bkey_packed *k;138	struct btree_nr_keys nr = {};139 140	for_each_bset(b, t)141		bset_tree_for_each_key(b, t, k)142			if (!bkey_deleted(k))143				btree_keys_account_key_add(&nr, t - b->set, k);144	return nr;145}146 147#ifdef CONFIG_BCACHEFS_DEBUG148 149void __bch2_verify_btree_nr_keys(struct btree *b)150{151	struct btree_nr_keys nr = bch2_btree_node_count_keys(b);152 153	BUG_ON(memcmp(&nr, &b->nr, sizeof(nr)));154}155 156static void bch2_btree_node_iter_next_check(struct btree_node_iter *_iter,157					    struct btree *b)158{159	struct btree_node_iter iter = *_iter;160	const struct bkey_packed *k, *n;161 162	k = bch2_btree_node_iter_peek_all(&iter, b);163	__bch2_btree_node_iter_advance(&iter, b);164	n = bch2_btree_node_iter_peek_all(&iter, b);165 166	bkey_unpack_key(b, k);167 168	if (n &&169	    bkey_iter_cmp(b, k, n) > 0) {170		struct btree_node_iter_set *set;171		struct bkey ku = bkey_unpack_key(b, k);172		struct bkey nu = bkey_unpack_key(b, n);173		struct printbuf buf1 = PRINTBUF;174		struct printbuf buf2 = PRINTBUF;175 176		bch2_dump_btree_node(NULL, b);177		bch2_bkey_to_text(&buf1, &ku);178		bch2_bkey_to_text(&buf2, &nu);179		printk(KERN_ERR "out of order/overlapping:\n%s\n%s\n",180		       buf1.buf, buf2.buf);181		printk(KERN_ERR "iter was:");182 183		btree_node_iter_for_each(_iter, set) {184			struct bkey_packed *k2 = __btree_node_offset_to_key(b, set->k);185			struct bset_tree *t = bch2_bkey_to_bset(b, k2);186			printk(" [%zi %zi]", t - b->set,187			       k2->_data - bset(b, t)->_data);188		}189		panic("\n");190	}191}192 193void bch2_btree_node_iter_verify(struct btree_node_iter *iter,194				 struct btree *b)195{196	struct btree_node_iter_set *set, *s2;197	struct bkey_packed *k, *p;198 199	if (bch2_btree_node_iter_end(iter))200		return;201 202	/* Verify no duplicates: */203	btree_node_iter_for_each(iter, set) {204		BUG_ON(set->k > set->end);205		btree_node_iter_for_each(iter, s2)206			BUG_ON(set != s2 && set->end == s2->end);207	}208 209	/* Verify that set->end is correct: */210	btree_node_iter_for_each(iter, set) {211		for_each_bset(b, t)212			if (set->end == t->end_offset) {213				BUG_ON(set->k < btree_bkey_first_offset(t) ||214				       set->k >= t->end_offset);215				goto found;216			}217		BUG();218found:219		do {} while (0);220	}221 222	/* Verify iterator is sorted: */223	btree_node_iter_for_each(iter, set)224		BUG_ON(set != iter->data &&225		       btree_node_iter_cmp(b, set[-1], set[0]) > 0);226 227	k = bch2_btree_node_iter_peek_all(iter, b);228 229	for_each_bset(b, t) {230		if (iter->data[0].end == t->end_offset)231			continue;232 233		p = bch2_bkey_prev_all(b, t,234			bch2_btree_node_iter_bset_pos(iter, b, t));235 236		BUG_ON(p && bkey_iter_cmp(b, k, p) < 0);237	}238}239 240void bch2_verify_insert_pos(struct btree *b, struct bkey_packed *where,241			    struct bkey_packed *insert, unsigned clobber_u64s)242{243	struct bset_tree *t = bch2_bkey_to_bset(b, where);244	struct bkey_packed *prev = bch2_bkey_prev_all(b, t, where);245	struct bkey_packed *next = (void *) ((u64 *) where->_data + clobber_u64s);246	struct printbuf buf1 = PRINTBUF;247	struct printbuf buf2 = PRINTBUF;248#if 0249	BUG_ON(prev &&250	       bkey_iter_cmp(b, prev, insert) > 0);251#else252	if (prev &&253	    bkey_iter_cmp(b, prev, insert) > 0) {254		struct bkey k1 = bkey_unpack_key(b, prev);255		struct bkey k2 = bkey_unpack_key(b, insert);256 257		bch2_dump_btree_node(NULL, b);258		bch2_bkey_to_text(&buf1, &k1);259		bch2_bkey_to_text(&buf2, &k2);260 261		panic("prev > insert:\n"262		      "prev    key %s\n"263		      "insert  key %s\n",264		      buf1.buf, buf2.buf);265	}266#endif267#if 0268	BUG_ON(next != btree_bkey_last(b, t) &&269	       bkey_iter_cmp(b, insert, next) > 0);270#else271	if (next != btree_bkey_last(b, t) &&272	    bkey_iter_cmp(b, insert, next) > 0) {273		struct bkey k1 = bkey_unpack_key(b, insert);274		struct bkey k2 = bkey_unpack_key(b, next);275 276		bch2_dump_btree_node(NULL, b);277		bch2_bkey_to_text(&buf1, &k1);278		bch2_bkey_to_text(&buf2, &k2);279 280		panic("insert > next:\n"281		      "insert  key %s\n"282		      "next    key %s\n",283		      buf1.buf, buf2.buf);284	}285#endif286}287 288#else289 290static inline void bch2_btree_node_iter_next_check(struct btree_node_iter *iter,291						   struct btree *b) {}292 293#endif294 295/* Auxiliary search trees */296 297#define BFLOAT_FAILED_UNPACKED	U8_MAX298#define BFLOAT_FAILED		U8_MAX299 300struct bkey_float {301	u8		exponent;302	u8		key_offset;303	u16		mantissa;304};305#define BKEY_MANTISSA_BITS	16306 307struct ro_aux_tree {308	u8			nothing[0];309	struct bkey_float	f[];310};311 312struct rw_aux_tree {313	u16		offset;314	struct bpos	k;315};316 317static unsigned bset_aux_tree_buf_end(const struct bset_tree *t)318{319	BUG_ON(t->aux_data_offset == U16_MAX);320 321	switch (bset_aux_tree_type(t)) {322	case BSET_NO_AUX_TREE:323		return t->aux_data_offset;324	case BSET_RO_AUX_TREE:325		return t->aux_data_offset +326			DIV_ROUND_UP(t->size * sizeof(struct bkey_float), 8);327	case BSET_RW_AUX_TREE:328		return t->aux_data_offset +329			DIV_ROUND_UP(sizeof(struct rw_aux_tree) * t->size, 8);330	default:331		BUG();332	}333}334 335static unsigned bset_aux_tree_buf_start(const struct btree *b,336					const struct bset_tree *t)337{338	return t == b->set339		? DIV_ROUND_UP(b->unpack_fn_len, 8)340		: bset_aux_tree_buf_end(t - 1);341}342 343static void *__aux_tree_base(const struct btree *b,344			     const struct bset_tree *t)345{346	return b->aux_data + t->aux_data_offset * 8;347}348 349static struct ro_aux_tree *ro_aux_tree_base(const struct btree *b,350					    const struct bset_tree *t)351{352	EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);353 354	return __aux_tree_base(b, t);355}356 357static struct bkey_float *bkey_float(const struct btree *b,358				     const struct bset_tree *t,359				     unsigned idx)360{361	return ro_aux_tree_base(b, t)->f + idx;362}363 364static void bset_aux_tree_verify(struct btree *b)365{366#ifdef CONFIG_BCACHEFS_DEBUG367	for_each_bset(b, t) {368		if (t->aux_data_offset == U16_MAX)369			continue;370 371		BUG_ON(t != b->set &&372		       t[-1].aux_data_offset == U16_MAX);373 374		BUG_ON(t->aux_data_offset < bset_aux_tree_buf_start(b, t));375		BUG_ON(t->aux_data_offset > btree_aux_data_u64s(b));376		BUG_ON(bset_aux_tree_buf_end(t) > btree_aux_data_u64s(b));377	}378#endif379}380 381void bch2_btree_keys_init(struct btree *b)382{383	unsigned i;384 385	b->nsets		= 0;386	memset(&b->nr, 0, sizeof(b->nr));387 388	for (i = 0; i < MAX_BSETS; i++)389		b->set[i].data_offset = U16_MAX;390 391	bch2_bset_set_no_aux_tree(b, b->set);392}393 394/* Binary tree stuff for auxiliary search trees */395 396/*397 * Cacheline/offset <-> bkey pointer arithmetic:398 *399 * t->tree is a binary search tree in an array; each node corresponds to a key400 * in one cacheline in t->set (BSET_CACHELINE bytes).401 *402 * This means we don't have to store the full index of the key that a node in403 * the binary tree points to; eytzinger1_to_inorder() gives us the cacheline, and404 * then bkey_float->m gives us the offset within that cacheline, in units of 8405 * bytes.406 *407 * cacheline_to_bkey() and friends abstract out all the pointer arithmetic to408 * make this work.409 *410 * To construct the bfloat for an arbitrary key we need to know what the key411 * immediately preceding it is: we have to check if the two keys differ in the412 * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size413 * of the previous key so we can walk backwards to it from t->tree[j]'s key.414 */415 416static inline void *bset_cacheline(const struct btree *b,417				   const struct bset_tree *t,418				   unsigned cacheline)419{420	return (void *) round_down((unsigned long) btree_bkey_first(b, t),421				   L1_CACHE_BYTES) +422		cacheline * BSET_CACHELINE;423}424 425static struct bkey_packed *cacheline_to_bkey(const struct btree *b,426					     const struct bset_tree *t,427					     unsigned cacheline,428					     unsigned offset)429{430	return bset_cacheline(b, t, cacheline) + offset * 8;431}432 433static unsigned bkey_to_cacheline(const struct btree *b,434				  const struct bset_tree *t,435				  const struct bkey_packed *k)436{437	return ((void *) k - bset_cacheline(b, t, 0)) / BSET_CACHELINE;438}439 440static ssize_t __bkey_to_cacheline_offset(const struct btree *b,441					  const struct bset_tree *t,442					  unsigned cacheline,443					  const struct bkey_packed *k)444{445	return (u64 *) k - (u64 *) bset_cacheline(b, t, cacheline);446}447 448static unsigned bkey_to_cacheline_offset(const struct btree *b,449					 const struct bset_tree *t,450					 unsigned cacheline,451					 const struct bkey_packed *k)452{453	size_t m = __bkey_to_cacheline_offset(b, t, cacheline, k);454 455	EBUG_ON(m > U8_MAX);456	return m;457}458 459static inline struct bkey_packed *tree_to_bkey(const struct btree *b,460					       const struct bset_tree *t,461					       unsigned j)462{463	return cacheline_to_bkey(b, t,464			__eytzinger1_to_inorder(j, t->size - 1, t->extra),465			bkey_float(b, t, j)->key_offset);466}467 468static struct rw_aux_tree *rw_aux_tree(const struct btree *b,469				       const struct bset_tree *t)470{471	EBUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);472 473	return __aux_tree_base(b, t);474}475 476/*477 * For the write set - the one we're currently inserting keys into - we don't478 * maintain a full search tree, we just keep a simple lookup table in t->prev.479 */480static struct bkey_packed *rw_aux_to_bkey(const struct btree *b,481					  struct bset_tree *t,482					  unsigned j)483{484	return __btree_node_offset_to_key(b, rw_aux_tree(b, t)[j].offset);485}486 487static void rw_aux_tree_set(const struct btree *b, struct bset_tree *t,488			    unsigned j, struct bkey_packed *k)489{490	EBUG_ON(k >= btree_bkey_last(b, t));491 492	rw_aux_tree(b, t)[j] = (struct rw_aux_tree) {493		.offset	= __btree_node_key_to_offset(b, k),494		.k	= bkey_unpack_pos(b, k),495	};496}497 498static void bch2_bset_verify_rw_aux_tree(struct btree *b,499					struct bset_tree *t)500{501	struct bkey_packed *k = btree_bkey_first(b, t);502	unsigned j = 0;503 504	if (!bch2_expensive_debug_checks)505		return;506 507	BUG_ON(bset_has_ro_aux_tree(t));508 509	if (!bset_has_rw_aux_tree(t))510		return;511 512	BUG_ON(t->size < 1);513	BUG_ON(rw_aux_to_bkey(b, t, j) != k);514 515	goto start;516	while (1) {517		if (rw_aux_to_bkey(b, t, j) == k) {518			BUG_ON(!bpos_eq(rw_aux_tree(b, t)[j].k,519					bkey_unpack_pos(b, k)));520start:521			if (++j == t->size)522				break;523 524			BUG_ON(rw_aux_tree(b, t)[j].offset <=525			       rw_aux_tree(b, t)[j - 1].offset);526		}527 528		k = bkey_p_next(k);529		BUG_ON(k >= btree_bkey_last(b, t));530	}531}532 533/* returns idx of first entry >= offset: */534static unsigned rw_aux_tree_bsearch(struct btree *b,535				    struct bset_tree *t,536				    unsigned offset)537{538	unsigned bset_offs = offset - btree_bkey_first_offset(t);539	unsigned bset_u64s = t->end_offset - btree_bkey_first_offset(t);540	unsigned idx = bset_u64s ? bset_offs * t->size / bset_u64s : 0;541 542	EBUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);543	EBUG_ON(!t->size);544	EBUG_ON(idx > t->size);545 546	while (idx < t->size &&547	       rw_aux_tree(b, t)[idx].offset < offset)548		idx++;549 550	while (idx &&551	       rw_aux_tree(b, t)[idx - 1].offset >= offset)552		idx--;553 554	EBUG_ON(idx < t->size &&555		rw_aux_tree(b, t)[idx].offset < offset);556	EBUG_ON(idx && rw_aux_tree(b, t)[idx - 1].offset >= offset);557	EBUG_ON(idx + 1 < t->size &&558		rw_aux_tree(b, t)[idx].offset ==559		rw_aux_tree(b, t)[idx + 1].offset);560 561	return idx;562}563 564static inline unsigned bkey_mantissa(const struct bkey_packed *k,565				     const struct bkey_float *f)566{567	u64 v;568 569	EBUG_ON(!bkey_packed(k));570 571	v = get_unaligned((u64 *) (((u8 *) k->_data) + (f->exponent >> 3)));572 573	/*574	 * In little endian, we're shifting off low bits (and then the bits we575	 * want are at the low end), in big endian we're shifting off high bits576	 * (and then the bits we want are at the high end, so we shift them577	 * back down):578	 */579#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__580	v >>= f->exponent & 7;581#else582	v >>= 64 - (f->exponent & 7) - BKEY_MANTISSA_BITS;583#endif584	return (u16) v;585}586 587static __always_inline void make_bfloat(struct btree *b, struct bset_tree *t,588					unsigned j,589					struct bkey_packed *min_key,590					struct bkey_packed *max_key)591{592	struct bkey_float *f = bkey_float(b, t, j);593	struct bkey_packed *m = tree_to_bkey(b, t, j);594	struct bkey_packed *l = is_power_of_2(j)595		? min_key596		: tree_to_bkey(b, t, j >> ffs(j));597	struct bkey_packed *r = is_power_of_2(j + 1)598		? max_key599		: tree_to_bkey(b, t, j >> (ffz(j) + 1));600	unsigned mantissa;601	int shift, exponent, high_bit;602 603	/*604	 * for failed bfloats, the lookup code falls back to comparing against605	 * the original key.606	 */607 608	if (!bkey_packed(l) || !bkey_packed(r) || !bkey_packed(m) ||609	    !b->nr_key_bits) {610		f->exponent = BFLOAT_FAILED_UNPACKED;611		return;612	}613 614	/*615	 * The greatest differing bit of l and r is the first bit we must616	 * include in the bfloat mantissa we're creating in order to do617	 * comparisons - that bit always becomes the high bit of618	 * bfloat->mantissa, and thus the exponent we're calculating here is619	 * the position of what will become the low bit in bfloat->mantissa:620	 *621	 * Note that this may be negative - we may be running off the low end622	 * of the key: we handle this later:623	 */624	high_bit = max(bch2_bkey_greatest_differing_bit(b, l, r),625		       min_t(unsigned, BKEY_MANTISSA_BITS, b->nr_key_bits) - 1);626	exponent = high_bit - (BKEY_MANTISSA_BITS - 1);627 628	/*629	 * Then we calculate the actual shift value, from the start of the key630	 * (k->_data), to get the key bits starting at exponent:631	 */632#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__633	shift = (int) (b->format.key_u64s * 64 - b->nr_key_bits) + exponent;634 635	EBUG_ON(shift + BKEY_MANTISSA_BITS > b->format.key_u64s * 64);636#else637	shift = high_bit_offset +638		b->nr_key_bits -639		exponent -640		BKEY_MANTISSA_BITS;641 642	EBUG_ON(shift < KEY_PACKED_BITS_START);643#endif644	EBUG_ON(shift < 0 || shift >= BFLOAT_FAILED);645 646	f->exponent = shift;647	mantissa = bkey_mantissa(m, f);648 649	/*650	 * If we've got garbage bits, set them to all 1s - it's legal for the651	 * bfloat to compare larger than the original key, but not smaller:652	 */653	if (exponent < 0)654		mantissa |= ~(~0U << -exponent);655 656	f->mantissa = mantissa;657}658 659/* bytes remaining - only valid for last bset: */660static unsigned __bset_tree_capacity(struct btree *b, const struct bset_tree *t)661{662	bset_aux_tree_verify(b);663 664	return btree_aux_data_bytes(b) - t->aux_data_offset * sizeof(u64);665}666 667static unsigned bset_ro_tree_capacity(struct btree *b, const struct bset_tree *t)668{669	return __bset_tree_capacity(b, t) / sizeof(struct bkey_float);670}671 672static unsigned bset_rw_tree_capacity(struct btree *b, const struct bset_tree *t)673{674	return __bset_tree_capacity(b, t) / sizeof(struct rw_aux_tree);675}676 677static noinline void __build_rw_aux_tree(struct btree *b, struct bset_tree *t)678{679	struct bkey_packed *k;680 681	t->size = 1;682	t->extra = BSET_RW_AUX_TREE_VAL;683	rw_aux_tree(b, t)[0].offset =684		__btree_node_key_to_offset(b, btree_bkey_first(b, t));685 686	bset_tree_for_each_key(b, t, k) {687		if (t->size == bset_rw_tree_capacity(b, t))688			break;689 690		if ((void *) k - (void *) rw_aux_to_bkey(b, t, t->size - 1) >691		    L1_CACHE_BYTES)692			rw_aux_tree_set(b, t, t->size++, k);693	}694}695 696static noinline void __build_ro_aux_tree(struct btree *b, struct bset_tree *t)697{698	struct bkey_packed *k = btree_bkey_first(b, t);699	struct bkey_i min_key, max_key;700	unsigned cacheline = 1;701 702	t->size = min(bkey_to_cacheline(b, t, btree_bkey_last(b, t)),703		      bset_ro_tree_capacity(b, t));704retry:705	if (t->size < 2) {706		t->size = 0;707		t->extra = BSET_NO_AUX_TREE_VAL;708		return;709	}710 711	t->extra = eytzinger1_extra(t->size - 1);712 713	/* First we figure out where the first key in each cacheline is */714	eytzinger1_for_each(j, t->size - 1) {715		while (bkey_to_cacheline(b, t, k) < cacheline)716			k = bkey_p_next(k);717 718		if (k >= btree_bkey_last(b, t)) {719			/* XXX: this path sucks */720			t->size--;721			goto retry;722		}723 724		bkey_float(b, t, j)->key_offset =725			bkey_to_cacheline_offset(b, t, cacheline++, k);726 727		EBUG_ON(tree_to_bkey(b, t, j) != k);728	}729 730	if (!bkey_pack_pos(bkey_to_packed(&min_key), b->data->min_key, b)) {731		bkey_init(&min_key.k);732		min_key.k.p = b->data->min_key;733	}734 735	if (!bkey_pack_pos(bkey_to_packed(&max_key), b->data->max_key, b)) {736		bkey_init(&max_key.k);737		max_key.k.p = b->data->max_key;738	}739 740	/* Then we build the tree */741	eytzinger1_for_each(j, t->size - 1)742		make_bfloat(b, t, j,743			    bkey_to_packed(&min_key),744			    bkey_to_packed(&max_key));745}746 747static void bset_alloc_tree(struct btree *b, struct bset_tree *t)748{749	struct bset_tree *i;750 751	for (i = b->set; i != t; i++)752		BUG_ON(bset_has_rw_aux_tree(i));753 754	bch2_bset_set_no_aux_tree(b, t);755 756	/* round up to next cacheline: */757	t->aux_data_offset = round_up(bset_aux_tree_buf_start(b, t),758				      SMP_CACHE_BYTES / sizeof(u64));759 760	bset_aux_tree_verify(b);761}762 763void bch2_bset_build_aux_tree(struct btree *b, struct bset_tree *t,764			     bool writeable)765{766	if (writeable767	    ? bset_has_rw_aux_tree(t)768	    : bset_has_ro_aux_tree(t))769		return;770 771	bset_alloc_tree(b, t);772 773	if (!__bset_tree_capacity(b, t))774		return;775 776	if (writeable)777		__build_rw_aux_tree(b, t);778	else779		__build_ro_aux_tree(b, t);780 781	bset_aux_tree_verify(b);782}783 784void bch2_bset_init_first(struct btree *b, struct bset *i)785{786	struct bset_tree *t;787 788	BUG_ON(b->nsets);789 790	memset(i, 0, sizeof(*i));791	get_random_bytes(&i->seq, sizeof(i->seq));792	SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);793 794	t = &b->set[b->nsets++];795	set_btree_bset(b, t, i);796}797 798void bch2_bset_init_next(struct btree *b, struct btree_node_entry *bne)799{800	struct bset *i = &bne->keys;801	struct bset_tree *t;802 803	BUG_ON(bset_byte_offset(b, bne) >= btree_buf_bytes(b));804	BUG_ON((void *) bne < (void *) btree_bkey_last(b, bset_tree_last(b)));805	BUG_ON(b->nsets >= MAX_BSETS);806 807	memset(i, 0, sizeof(*i));808	i->seq = btree_bset_first(b)->seq;809	SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);810 811	t = &b->set[b->nsets++];812	set_btree_bset(b, t, i);813}814 815/*816 * find _some_ key in the same bset as @k that precedes @k - not necessarily the817 * immediate predecessor:818 */819static struct bkey_packed *__bkey_prev(struct btree *b, struct bset_tree *t,820				       struct bkey_packed *k)821{822	struct bkey_packed *p;823	unsigned offset;824	int j;825 826	EBUG_ON(k < btree_bkey_first(b, t) ||827		k > btree_bkey_last(b, t));828 829	if (k == btree_bkey_first(b, t))830		return NULL;831 832	switch (bset_aux_tree_type(t)) {833	case BSET_NO_AUX_TREE:834		p = btree_bkey_first(b, t);835		break;836	case BSET_RO_AUX_TREE:837		j = min_t(unsigned, t->size - 1, bkey_to_cacheline(b, t, k));838 839		do {840			p = j ? tree_to_bkey(b, t,841					__inorder_to_eytzinger1(j--,842							t->size - 1, t->extra))843			      : btree_bkey_first(b, t);844		} while (p >= k);845		break;846	case BSET_RW_AUX_TREE:847		offset = __btree_node_key_to_offset(b, k);848		j = rw_aux_tree_bsearch(b, t, offset);849		p = j ? rw_aux_to_bkey(b, t, j - 1)850		      : btree_bkey_first(b, t);851		break;852	}853 854	return p;855}856 857struct bkey_packed *bch2_bkey_prev_filter(struct btree *b,858					  struct bset_tree *t,859					  struct bkey_packed *k,860					  unsigned min_key_type)861{862	struct bkey_packed *p, *i, *ret = NULL, *orig_k = k;863 864	while ((p = __bkey_prev(b, t, k)) && !ret) {865		for (i = p; i != k; i = bkey_p_next(i))866			if (i->type >= min_key_type)867				ret = i;868 869		k = p;870	}871 872	if (bch2_expensive_debug_checks) {873		BUG_ON(ret >= orig_k);874 875		for (i = ret876			? bkey_p_next(ret)877			: btree_bkey_first(b, t);878		     i != orig_k;879		     i = bkey_p_next(i))880			BUG_ON(i->type >= min_key_type);881	}882 883	return ret;884}885 886/* Insert */887 888static void rw_aux_tree_insert_entry(struct btree *b,889				     struct bset_tree *t,890				     unsigned idx)891{892	EBUG_ON(!idx || idx > t->size);893	struct bkey_packed *start = rw_aux_to_bkey(b, t, idx - 1);894	struct bkey_packed *end = idx < t->size895				  ? rw_aux_to_bkey(b, t, idx)896				  : btree_bkey_last(b, t);897 898	if (t->size < bset_rw_tree_capacity(b, t) &&899	    (void *) end - (void *) start > L1_CACHE_BYTES) {900		struct bkey_packed *k = start;901 902		while (1) {903			k = bkey_p_next(k);904			if (k == end)905				break;906 907			if ((void *) k - (void *) start >= L1_CACHE_BYTES) {908				memmove(&rw_aux_tree(b, t)[idx + 1],909					&rw_aux_tree(b, t)[idx],910					(void *) &rw_aux_tree(b, t)[t->size] -911					(void *) &rw_aux_tree(b, t)[idx]);912				t->size++;913				rw_aux_tree_set(b, t, idx, k);914				break;915			}916		}917	}918}919 920static void bch2_bset_fix_lookup_table(struct btree *b,921				       struct bset_tree *t,922				       struct bkey_packed *_where,923				       unsigned clobber_u64s,924				       unsigned new_u64s)925{926	int shift = new_u64s - clobber_u64s;927	unsigned idx, j, where = __btree_node_key_to_offset(b, _where);928 929	EBUG_ON(bset_has_ro_aux_tree(t));930 931	if (!bset_has_rw_aux_tree(t))932		return;933 934	if (where > rw_aux_tree(b, t)[t->size - 1].offset) {935		rw_aux_tree_insert_entry(b, t, t->size);936		goto verify;937	}938 939	/* returns first entry >= where */940	idx = rw_aux_tree_bsearch(b, t, where);941 942	if (rw_aux_tree(b, t)[idx].offset == where) {943		if (!idx) { /* never delete first entry */944			idx++;945		} else if (where < t->end_offset) {946			rw_aux_tree_set(b, t, idx++, _where);947		} else {948			EBUG_ON(where != t->end_offset);949			rw_aux_tree_insert_entry(b, t, --t->size);950			goto verify;951		}952	}953 954	EBUG_ON(idx < t->size && rw_aux_tree(b, t)[idx].offset <= where);955	if (idx < t->size &&956	    rw_aux_tree(b, t)[idx].offset + shift ==957	    rw_aux_tree(b, t)[idx - 1].offset) {958		memmove(&rw_aux_tree(b, t)[idx],959			&rw_aux_tree(b, t)[idx + 1],960			(void *) &rw_aux_tree(b, t)[t->size] -961			(void *) &rw_aux_tree(b, t)[idx + 1]);962		t->size -= 1;963	}964 965	for (j = idx; j < t->size; j++)966		rw_aux_tree(b, t)[j].offset += shift;967 968	EBUG_ON(idx < t->size &&969		rw_aux_tree(b, t)[idx].offset ==970		rw_aux_tree(b, t)[idx - 1].offset);971 972	rw_aux_tree_insert_entry(b, t, idx);973 974verify:975	bch2_bset_verify_rw_aux_tree(b, t);976	bset_aux_tree_verify(b);977}978 979void bch2_bset_insert(struct btree *b,980		      struct bkey_packed *where,981		      struct bkey_i *insert,982		      unsigned clobber_u64s)983{984	struct bkey_format *f = &b->format;985	struct bset_tree *t = bset_tree_last(b);986	struct bkey_packed packed, *src = bkey_to_packed(insert);987 988	bch2_bset_verify_rw_aux_tree(b, t);989	bch2_verify_insert_pos(b, where, bkey_to_packed(insert), clobber_u64s);990 991	if (bch2_bkey_pack_key(&packed, &insert->k, f))992		src = &packed;993 994	if (!bkey_deleted(&insert->k))995		btree_keys_account_key_add(&b->nr, t - b->set, src);996 997	if (src->u64s != clobber_u64s) {998		u64 *src_p = (u64 *) where->_data + clobber_u64s;999		u64 *dst_p = (u64 *) where->_data + src->u64s;1000 1001		EBUG_ON((int) le16_to_cpu(bset(b, t)->u64s) <1002			(int) clobber_u64s - src->u64s);1003 1004		memmove_u64s(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);1005		le16_add_cpu(&bset(b, t)->u64s, src->u64s - clobber_u64s);1006		set_btree_bset_end(b, t);1007	}1008 1009	memcpy_u64s_small(where, src,1010		    bkeyp_key_u64s(f, src));1011	memcpy_u64s(bkeyp_val(f, where), &insert->v,1012		    bkeyp_val_u64s(f, src));1013 1014	if (src->u64s != clobber_u64s)1015		bch2_bset_fix_lookup_table(b, t, where, clobber_u64s, src->u64s);1016 1017	bch2_verify_btree_nr_keys(b);1018}1019 1020void bch2_bset_delete(struct btree *b,1021		      struct bkey_packed *where,1022		      unsigned clobber_u64s)1023{1024	struct bset_tree *t = bset_tree_last(b);1025	u64 *src_p = (u64 *) where->_data + clobber_u64s;1026	u64 *dst_p = where->_data;1027 1028	bch2_bset_verify_rw_aux_tree(b, t);1029 1030	EBUG_ON(le16_to_cpu(bset(b, t)->u64s) < clobber_u64s);1031 1032	memmove_u64s_down(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);1033	le16_add_cpu(&bset(b, t)->u64s, -clobber_u64s);1034	set_btree_bset_end(b, t);1035 1036	bch2_bset_fix_lookup_table(b, t, where, clobber_u64s, 0);1037}1038 1039/* Lookup */1040 1041__flatten1042static struct bkey_packed *bset_search_write_set(const struct btree *b,1043				struct bset_tree *t,1044				struct bpos *search)1045{1046	unsigned l = 0, r = t->size;1047 1048	while (l + 1 != r) {1049		unsigned m = (l + r) >> 1;1050 1051		if (bpos_lt(rw_aux_tree(b, t)[m].k, *search))1052			l = m;1053		else1054			r = m;1055	}1056 1057	return rw_aux_to_bkey(b, t, l);1058}1059 1060static inline void prefetch_four_cachelines(void *p)1061{1062#ifdef CONFIG_X86_641063	asm("prefetcht0 (-127 + 64 * 0)(%0);"1064	    "prefetcht0 (-127 + 64 * 1)(%0);"1065	    "prefetcht0 (-127 + 64 * 2)(%0);"1066	    "prefetcht0 (-127 + 64 * 3)(%0);"1067	    :1068	    : "r" (p + 127));1069#else1070	prefetch(p + L1_CACHE_BYTES * 0);1071	prefetch(p + L1_CACHE_BYTES * 1);1072	prefetch(p + L1_CACHE_BYTES * 2);1073	prefetch(p + L1_CACHE_BYTES * 3);1074#endif1075}1076 1077static inline bool bkey_mantissa_bits_dropped(const struct btree *b,1078					      const struct bkey_float *f)1079{1080#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__1081	unsigned key_bits_start = b->format.key_u64s * 64 - b->nr_key_bits;1082 1083	return f->exponent > key_bits_start;1084#else1085	unsigned key_bits_end = high_bit_offset + b->nr_key_bits;1086 1087	return f->exponent + BKEY_MANTISSA_BITS < key_bits_end;1088#endif1089}1090 1091__flatten1092static struct bkey_packed *bset_search_tree(const struct btree *b,1093				const struct bset_tree *t,1094				const struct bpos *search,1095				const struct bkey_packed *packed_search)1096{1097	struct ro_aux_tree *base = ro_aux_tree_base(b, t);1098	struct bkey_float *f;1099	struct bkey_packed *k;1100	unsigned inorder, n = 1, l, r;1101	int cmp;1102 1103	do {1104		if (likely(n << 4 < t->size))1105			prefetch(&base->f[n << 4]);1106 1107		f = &base->f[n];1108		if (unlikely(f->exponent >= BFLOAT_FAILED))1109			goto slowpath;1110 1111		l = f->mantissa;1112		r = bkey_mantissa(packed_search, f);1113 1114		if (unlikely(l == r) && bkey_mantissa_bits_dropped(b, f))1115			goto slowpath;1116 1117		n = n * 2 + (l < r);1118		continue;1119slowpath:1120		k = tree_to_bkey(b, t, n);1121		cmp = bkey_cmp_p_or_unp(b, k, packed_search, search);1122		if (!cmp)1123			return k;1124 1125		n = n * 2 + (cmp < 0);1126	} while (n < t->size);1127 1128	inorder = __eytzinger1_to_inorder(n >> 1, t->size - 1, t->extra);1129 1130	/*1131	 * n would have been the node we recursed to - the low bit tells us if1132	 * we recursed left or recursed right.1133	 */1134	if (likely(!(n & 1))) {1135		--inorder;1136		if (unlikely(!inorder))1137			return btree_bkey_first(b, t);1138 1139		f = &base->f[eytzinger1_prev(n >> 1, t->size - 1)];1140	}1141 1142	return cacheline_to_bkey(b, t, inorder, f->key_offset);1143}1144 1145static __always_inline __flatten1146struct bkey_packed *__bch2_bset_search(struct btree *b,1147				struct bset_tree *t,1148				struct bpos *search,1149				const struct bkey_packed *lossy_packed_search)1150{1151 1152	/*1153	 * First, we search for a cacheline, then lastly we do a linear search1154	 * within that cacheline.1155	 *1156	 * To search for the cacheline, there's three different possibilities:1157	 *  * The set is too small to have a search tree, so we just do a linear1158	 *    search over the whole set.1159	 *  * The set is the one we're currently inserting into; keeping a full1160	 *    auxiliary search tree up to date would be too expensive, so we1161	 *    use a much simpler lookup table to do a binary search -1162	 *    bset_search_write_set().1163	 *  * Or we use the auxiliary search tree we constructed earlier -1164	 *    bset_search_tree()1165	 */1166 1167	switch (bset_aux_tree_type(t)) {1168	case BSET_NO_AUX_TREE:1169		return btree_bkey_first(b, t);1170	case BSET_RW_AUX_TREE:1171		return bset_search_write_set(b, t, search);1172	case BSET_RO_AUX_TREE:1173		return bset_search_tree(b, t, search, lossy_packed_search);1174	default:1175		BUG();1176	}1177}1178 1179static __always_inline __flatten1180struct bkey_packed *bch2_bset_search_linear(struct btree *b,1181				struct bset_tree *t,1182				struct bpos *search,1183				struct bkey_packed *packed_search,1184				const struct bkey_packed *lossy_packed_search,1185				struct bkey_packed *m)1186{1187	if (lossy_packed_search)1188		while (m != btree_bkey_last(b, t) &&1189		       bkey_iter_cmp_p_or_unp(b, m,1190					lossy_packed_search, search) < 0)1191			m = bkey_p_next(m);1192 1193	if (!packed_search)1194		while (m != btree_bkey_last(b, t) &&1195		       bkey_iter_pos_cmp(b, m, search) < 0)1196			m = bkey_p_next(m);1197 1198	if (bch2_expensive_debug_checks) {1199		struct bkey_packed *prev = bch2_bkey_prev_all(b, t, m);1200 1201		BUG_ON(prev &&1202		       bkey_iter_cmp_p_or_unp(b, prev,1203					packed_search, search) >= 0);1204	}1205 1206	return m;1207}1208 1209/* Btree node iterator */1210 1211static inline void __bch2_btree_node_iter_push(struct btree_node_iter *iter,1212			      struct btree *b,1213			      const struct bkey_packed *k,1214			      const struct bkey_packed *end)1215{1216	if (k != end) {1217		struct btree_node_iter_set *pos;1218 1219		btree_node_iter_for_each(iter, pos)1220			;1221 1222		BUG_ON(pos >= iter->data + ARRAY_SIZE(iter->data));1223		*pos = (struct btree_node_iter_set) {1224			__btree_node_key_to_offset(b, k),1225			__btree_node_key_to_offset(b, end)1226		};1227	}1228}1229 1230void bch2_btree_node_iter_push(struct btree_node_iter *iter,1231			       struct btree *b,1232			       const struct bkey_packed *k,1233			       const struct bkey_packed *end)1234{1235	__bch2_btree_node_iter_push(iter, b, k, end);1236	bch2_btree_node_iter_sort(iter, b);1237}1238 1239noinline __flatten __cold1240static void btree_node_iter_init_pack_failed(struct btree_node_iter *iter,1241			      struct btree *b, struct bpos *search)1242{1243	struct bkey_packed *k;1244 1245	trace_bkey_pack_pos_fail(search);1246 1247	bch2_btree_node_iter_init_from_start(iter, b);1248 1249	while ((k = bch2_btree_node_iter_peek(iter, b)) &&1250	       bkey_iter_pos_cmp(b, k, search) < 0)1251		bch2_btree_node_iter_advance(iter, b);1252}1253 1254/**1255 * bch2_btree_node_iter_init - initialize a btree node iterator, starting from a1256 * given position1257 *1258 * @iter:	iterator to initialize1259 * @b:		btree node to search1260 * @search:	search key1261 *1262 * Main entry point to the lookup code for individual btree nodes:1263 *1264 * NOTE:1265 *1266 * When you don't filter out deleted keys, btree nodes _do_ contain duplicate1267 * keys. This doesn't matter for most code, but it does matter for lookups.1268 *1269 * Some adjacent keys with a string of equal keys:1270 *	i j k k k k l m1271 *1272 * If you search for k, the lookup code isn't guaranteed to return you any1273 * specific k. The lookup code is conceptually doing a binary search and1274 * iterating backwards is very expensive so if the pivot happens to land at the1275 * last k that's what you'll get.1276 *1277 * This works out ok, but it's something to be aware of:1278 *1279 *  - For non extents, we guarantee that the live key comes last - see1280 *    btree_node_iter_cmp(), keys_out_of_order(). So the duplicates you don't1281 *    see will only be deleted keys you don't care about.1282 *1283 *  - For extents, deleted keys sort last (see the comment at the top of this1284 *    file). But when you're searching for extents, you actually want the first1285 *    key strictly greater than your search key - an extent that compares equal1286 *    to the search key is going to have 0 sectors after the search key.1287 *1288 *    But this does mean that we can't just search for1289 *    bpos_successor(start_of_range) to get the first extent that overlaps with1290 *    the range we want - if we're unlucky and there's an extent that ends1291 *    exactly where we searched, then there could be a deleted key at the same1292 *    position and we'd get that when we search instead of the preceding extent1293 *    we needed.1294 *1295 *    So we've got to search for start_of_range, then after the lookup iterate1296 *    past any extents that compare equal to the position we searched for.1297 */1298__flatten1299void bch2_btree_node_iter_init(struct btree_node_iter *iter,1300			       struct btree *b, struct bpos *search)1301{1302	struct bkey_packed p, *packed_search = NULL;1303	struct btree_node_iter_set *pos = iter->data;1304	struct bkey_packed *k[MAX_BSETS];1305	unsigned i;1306 1307	EBUG_ON(bpos_lt(*search, b->data->min_key));1308	EBUG_ON(bpos_gt(*search, b->data->max_key));1309	bset_aux_tree_verify(b);1310 1311	memset(iter, 0, sizeof(*iter));1312 1313	switch (bch2_bkey_pack_pos_lossy(&p, *search, b)) {1314	case BKEY_PACK_POS_EXACT:1315		packed_search = &p;1316		break;1317	case BKEY_PACK_POS_SMALLER:1318		packed_search = NULL;1319		break;1320	case BKEY_PACK_POS_FAIL:1321		btree_node_iter_init_pack_failed(iter, b, search);1322		return;1323	}1324 1325	for (i = 0; i < b->nsets; i++) {1326		k[i] = __bch2_bset_search(b, b->set + i, search, &p);1327		prefetch_four_cachelines(k[i]);1328	}1329 1330	for (i = 0; i < b->nsets; i++) {1331		struct bset_tree *t = b->set + i;1332		struct bkey_packed *end = btree_bkey_last(b, t);1333 1334		k[i] = bch2_bset_search_linear(b, t, search,1335					       packed_search, &p, k[i]);1336		if (k[i] != end)1337			*pos++ = (struct btree_node_iter_set) {1338				__btree_node_key_to_offset(b, k[i]),1339				__btree_node_key_to_offset(b, end)1340			};1341	}1342 1343	bch2_btree_node_iter_sort(iter, b);1344}1345 1346void bch2_btree_node_iter_init_from_start(struct btree_node_iter *iter,1347					  struct btree *b)1348{1349	memset(iter, 0, sizeof(*iter));1350 1351	for_each_bset(b, t)1352		__bch2_btree_node_iter_push(iter, b,1353					   btree_bkey_first(b, t),1354					   btree_bkey_last(b, t));1355	bch2_btree_node_iter_sort(iter, b);1356}1357 1358struct bkey_packed *bch2_btree_node_iter_bset_pos(struct btree_node_iter *iter,1359						  struct btree *b,1360						  struct bset_tree *t)1361{1362	struct btree_node_iter_set *set;1363 1364	btree_node_iter_for_each(iter, set)1365		if (set->end == t->end_offset)1366			return __btree_node_offset_to_key(b, set->k);1367 1368	return btree_bkey_last(b, t);1369}1370 1371static inline bool btree_node_iter_sort_two(struct btree_node_iter *iter,1372					    struct btree *b,1373					    unsigned first)1374{1375	bool ret;1376 1377	if ((ret = (btree_node_iter_cmp(b,1378					iter->data[first],1379					iter->data[first + 1]) > 0)))1380		swap(iter->data[first], iter->data[first + 1]);1381	return ret;1382}1383 1384void bch2_btree_node_iter_sort(struct btree_node_iter *iter,1385			       struct btree *b)1386{1387	/* unrolled bubble sort: */1388 1389	if (!__btree_node_iter_set_end(iter, 2)) {1390		btree_node_iter_sort_two(iter, b, 0);1391		btree_node_iter_sort_two(iter, b, 1);1392	}1393 1394	if (!__btree_node_iter_set_end(iter, 1))1395		btree_node_iter_sort_two(iter, b, 0);1396}1397 1398void bch2_btree_node_iter_set_drop(struct btree_node_iter *iter,1399				   struct btree_node_iter_set *set)1400{1401	struct btree_node_iter_set *last =1402		iter->data + ARRAY_SIZE(iter->data) - 1;1403 1404	memmove(&set[0], &set[1], (void *) last - (void *) set);1405	*last = (struct btree_node_iter_set) { 0, 0 };1406}1407 1408static inline void __bch2_btree_node_iter_advance(struct btree_node_iter *iter,1409						  struct btree *b)1410{1411	iter->data->k += __bch2_btree_node_iter_peek_all(iter, b)->u64s;1412 1413	EBUG_ON(iter->data->k > iter->data->end);1414 1415	if (unlikely(__btree_node_iter_set_end(iter, 0))) {1416		/* avoid an expensive memmove call: */1417		iter->data[0] = iter->data[1];1418		iter->data[1] = iter->data[2];1419		iter->data[2] = (struct btree_node_iter_set) { 0, 0 };1420		return;1421	}1422 1423	if (__btree_node_iter_set_end(iter, 1))1424		return;1425 1426	if (!btree_node_iter_sort_two(iter, b, 0))1427		return;1428 1429	if (__btree_node_iter_set_end(iter, 2))1430		return;1431 1432	btree_node_iter_sort_two(iter, b, 1);1433}1434 1435void bch2_btree_node_iter_advance(struct btree_node_iter *iter,1436				  struct btree *b)1437{1438	if (bch2_expensive_debug_checks) {1439		bch2_btree_node_iter_verify(iter, b);1440		bch2_btree_node_iter_next_check(iter, b);1441	}1442 1443	__bch2_btree_node_iter_advance(iter, b);1444}1445 1446/*1447 * Expensive:1448 */1449struct bkey_packed *bch2_btree_node_iter_prev_all(struct btree_node_iter *iter,1450						  struct btree *b)1451{1452	struct bkey_packed *k, *prev = NULL;1453	struct btree_node_iter_set *set;1454	unsigned end = 0;1455 1456	if (bch2_expensive_debug_checks)1457		bch2_btree_node_iter_verify(iter, b);1458 1459	for_each_bset(b, t) {1460		k = bch2_bkey_prev_all(b, t,1461			bch2_btree_node_iter_bset_pos(iter, b, t));1462		if (k &&1463		    (!prev || bkey_iter_cmp(b, k, prev) > 0)) {1464			prev = k;1465			end = t->end_offset;1466		}1467	}1468 1469	if (!prev)1470		return NULL;1471 1472	/*1473	 * We're manually memmoving instead of just calling sort() to ensure the1474	 * prev we picked ends up in slot 0 - sort won't necessarily put it1475	 * there because of duplicate deleted keys:1476	 */1477	btree_node_iter_for_each(iter, set)1478		if (set->end == end)1479			goto found;1480 1481	BUG_ON(set != &iter->data[__btree_node_iter_used(iter)]);1482found:1483	BUG_ON(set >= iter->data + ARRAY_SIZE(iter->data));1484 1485	memmove(&iter->data[1],1486		&iter->data[0],1487		(void *) set - (void *) &iter->data[0]);1488 1489	iter->data[0].k = __btree_node_key_to_offset(b, prev);1490	iter->data[0].end = end;1491 1492	if (bch2_expensive_debug_checks)1493		bch2_btree_node_iter_verify(iter, b);1494	return prev;1495}1496 1497struct bkey_packed *bch2_btree_node_iter_prev(struct btree_node_iter *iter,1498					      struct btree *b)1499{1500	struct bkey_packed *prev;1501 1502	do {1503		prev = bch2_btree_node_iter_prev_all(iter, b);1504	} while (prev && bkey_deleted(prev));1505 1506	return prev;1507}1508 1509struct bkey_s_c bch2_btree_node_iter_peek_unpack(struct btree_node_iter *iter,1510						 struct btree *b,1511						 struct bkey *u)1512{1513	struct bkey_packed *k = bch2_btree_node_iter_peek(iter, b);1514 1515	return k ? bkey_disassemble(b, k, u) : bkey_s_c_null;1516}1517 1518/* Mergesort */1519 1520void bch2_btree_keys_stats(const struct btree *b, struct bset_stats *stats)1521{1522	for_each_bset_c(b, t) {1523		enum bset_aux_tree_type type = bset_aux_tree_type(t);1524		size_t j;1525 1526		stats->sets[type].nr++;1527		stats->sets[type].bytes += le16_to_cpu(bset(b, t)->u64s) *1528			sizeof(u64);1529 1530		if (bset_has_ro_aux_tree(t)) {1531			stats->floats += t->size - 1;1532 1533			for (j = 1; j < t->size; j++)1534				stats->failed +=1535					bkey_float(b, t, j)->exponent ==1536					BFLOAT_FAILED;1537		}1538	}1539}1540 1541void bch2_bfloat_to_text(struct printbuf *out, struct btree *b,1542			 struct bkey_packed *k)1543{1544	struct bset_tree *t = bch2_bkey_to_bset(b, k);1545	struct bkey uk;1546	unsigned j, inorder;1547 1548	if (!bset_has_ro_aux_tree(t))1549		return;1550 1551	inorder = bkey_to_cacheline(b, t, k);1552	if (!inorder || inorder >= t->size)1553		return;1554 1555	j = __inorder_to_eytzinger1(inorder, t->size - 1, t->extra);1556	if (k != tree_to_bkey(b, t, j))1557		return;1558 1559	switch (bkey_float(b, t, j)->exponent) {1560	case BFLOAT_FAILED:1561		uk = bkey_unpack_key(b, k);1562		prt_printf(out,1563		       "    failed unpacked at depth %u\n"1564		       "\t",1565		       ilog2(j));1566		bch2_bpos_to_text(out, uk.p);1567		prt_printf(out, "\n");1568		break;1569	}1570}1571