2 * Code for working with individual keys, and sorted sets of keys with in a
5 * Copyright 2012 Google, Inc.
8 #define pr_fmt(fmt) "bcache: %s() " fmt "\n", __func__
13 #include <linux/console.h>
14 #include <linux/sched/clock.h>
15 #include <linux/random.h>
16 #include <linux/prefetch.h>
18 #ifdef CONFIG_BCACHE_DEBUG
20 void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set)
22 struct bkey *k, *next;
24 for (k = i->start; k < bset_bkey_last(i); k = next) {
27 printk(KERN_ERR "block %u key %u/%u: ", set,
28 (unsigned) ((u64 *) k - i->d), i->keys);
31 b->ops->key_dump(b, k);
33 printk("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k));
35 if (next < bset_bkey_last(i) &&
36 bkey_cmp(k, b->ops->is_extents ?
37 &START_KEY(next) : next) > 0)
38 printk(KERN_ERR "Key skipped backwards\n");
42 void bch_dump_bucket(struct btree_keys *b)
47 for (i = 0; i <= b->nsets; i++)
48 bch_dump_bset(b, b->set[i].data,
49 bset_sector_offset(b, b->set[i].data));
53 int __bch_count_data(struct btree_keys *b)
56 struct btree_iter iter;
59 if (b->ops->is_extents)
60 for_each_key(b, k, &iter)
65 void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
68 struct bkey *k, *p = NULL;
69 struct btree_iter iter;
72 for_each_key(b, k, &iter) {
73 if (b->ops->is_extents) {
74 err = "Keys out of order";
75 if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
78 if (bch_ptr_invalid(b, k))
81 err = "Overlapping keys";
82 if (p && bkey_cmp(p, &START_KEY(k)) > 0)
85 if (bch_ptr_bad(b, k))
88 err = "Duplicate keys";
89 if (p && !bkey_cmp(p, k))
95 err = "Key larger than btree node key";
96 if (p && bkey_cmp(p, &b->key) > 0)
107 panic("bch_check_keys error: %s:\n", err);
110 static void bch_btree_iter_next_check(struct btree_iter *iter)
112 struct bkey *k = iter->data->k, *next = bkey_next(k);
114 if (next < iter->data->end &&
115 bkey_cmp(k, iter->b->ops->is_extents ?
116 &START_KEY(next) : next) > 0) {
117 bch_dump_bucket(iter->b);
118 panic("Key skipped backwards\n");
124 static inline void bch_btree_iter_next_check(struct btree_iter *iter) {}
130 int __bch_keylist_realloc(struct keylist *l, unsigned u64s)
132 size_t oldsize = bch_keylist_nkeys(l);
133 size_t newsize = oldsize + u64s;
134 uint64_t *old_keys = l->keys_p == l->inline_keys ? NULL : l->keys_p;
137 newsize = roundup_pow_of_two(newsize);
139 if (newsize <= KEYLIST_INLINE ||
140 roundup_pow_of_two(oldsize) == newsize)
143 new_keys = krealloc(old_keys, sizeof(uint64_t) * newsize, GFP_NOIO);
149 memcpy(new_keys, l->inline_keys, sizeof(uint64_t) * oldsize);
151 l->keys_p = new_keys;
152 l->top_p = new_keys + oldsize;
157 struct bkey *bch_keylist_pop(struct keylist *l)
159 struct bkey *k = l->keys;
164 while (bkey_next(k) != l->top)
170 void bch_keylist_pop_front(struct keylist *l)
172 l->top_p -= bkey_u64s(l->keys);
176 bch_keylist_bytes(l));
179 /* Key/pointer manipulation */
181 void bch_bkey_copy_single_ptr(struct bkey *dest, const struct bkey *src,
184 BUG_ON(i > KEY_PTRS(src));
186 /* Only copy the header, key, and one pointer. */
187 memcpy(dest, src, 2 * sizeof(uint64_t));
188 dest->ptr[0] = src->ptr[i];
189 SET_KEY_PTRS(dest, 1);
190 /* We didn't copy the checksum so clear that bit. */
191 SET_KEY_CSUM(dest, 0);
194 bool __bch_cut_front(const struct bkey *where, struct bkey *k)
198 if (bkey_cmp(where, &START_KEY(k)) <= 0)
201 if (bkey_cmp(where, k) < 0)
202 len = KEY_OFFSET(k) - KEY_OFFSET(where);
204 bkey_copy_key(k, where);
206 for (i = 0; i < KEY_PTRS(k); i++)
207 SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + KEY_SIZE(k) - len);
209 BUG_ON(len > KEY_SIZE(k));
210 SET_KEY_SIZE(k, len);
214 bool __bch_cut_back(const struct bkey *where, struct bkey *k)
218 if (bkey_cmp(where, k) >= 0)
221 BUG_ON(KEY_INODE(where) != KEY_INODE(k));
223 if (bkey_cmp(where, &START_KEY(k)) > 0)
224 len = KEY_OFFSET(where) - KEY_START(k);
226 bkey_copy_key(k, where);
228 BUG_ON(len > KEY_SIZE(k));
229 SET_KEY_SIZE(k, len);
233 /* Auxiliary search trees */
236 #define BKEY_MID_BITS 3
237 #define BKEY_EXPONENT_BITS 7
238 #define BKEY_MANTISSA_BITS (32 - BKEY_MID_BITS - BKEY_EXPONENT_BITS)
239 #define BKEY_MANTISSA_MASK ((1 << BKEY_MANTISSA_BITS) - 1)
242 unsigned exponent:BKEY_EXPONENT_BITS;
243 unsigned m:BKEY_MID_BITS;
244 unsigned mantissa:BKEY_MANTISSA_BITS;
248 * BSET_CACHELINE was originally intended to match the hardware cacheline size -
249 * it used to be 64, but I realized the lookup code would touch slightly less
250 * memory if it was 128.
252 * It definites the number of bytes (in struct bset) per struct bkey_float in
253 * the auxiliar search tree - when we're done searching the bset_float tree we
254 * have this many bytes left that we do a linear search over.
256 * Since (after level 5) every level of the bset_tree is on a new cacheline,
257 * we're touching one fewer cacheline in the bset tree in exchange for one more
258 * cacheline in the linear search - but the linear search might stop before it
259 * gets to the second cacheline.
262 #define BSET_CACHELINE 128
264 /* Space required for the btree node keys */
265 static inline size_t btree_keys_bytes(struct btree_keys *b)
267 return PAGE_SIZE << b->page_order;
270 static inline size_t btree_keys_cachelines(struct btree_keys *b)
272 return btree_keys_bytes(b) / BSET_CACHELINE;
275 /* Space required for the auxiliary search trees */
276 static inline size_t bset_tree_bytes(struct btree_keys *b)
278 return btree_keys_cachelines(b) * sizeof(struct bkey_float);
281 /* Space required for the prev pointers */
282 static inline size_t bset_prev_bytes(struct btree_keys *b)
284 return btree_keys_cachelines(b) * sizeof(uint8_t);
287 /* Memory allocation */
289 void bch_btree_keys_free(struct btree_keys *b)
291 struct bset_tree *t = b->set;
293 if (bset_prev_bytes(b) < PAGE_SIZE)
296 free_pages((unsigned long) t->prev,
297 get_order(bset_prev_bytes(b)));
299 if (bset_tree_bytes(b) < PAGE_SIZE)
302 free_pages((unsigned long) t->tree,
303 get_order(bset_tree_bytes(b)));
305 free_pages((unsigned long) t->data, b->page_order);
311 EXPORT_SYMBOL(bch_btree_keys_free);
313 int bch_btree_keys_alloc(struct btree_keys *b, unsigned page_order, gfp_t gfp)
315 struct bset_tree *t = b->set;
319 b->page_order = page_order;
321 t->data = (void *) __get_free_pages(gfp, b->page_order);
325 t->tree = bset_tree_bytes(b) < PAGE_SIZE
326 ? kmalloc(bset_tree_bytes(b), gfp)
327 : (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b)));
331 t->prev = bset_prev_bytes(b) < PAGE_SIZE
332 ? kmalloc(bset_prev_bytes(b), gfp)
333 : (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b)));
339 bch_btree_keys_free(b);
342 EXPORT_SYMBOL(bch_btree_keys_alloc);
344 void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
345 bool *expensive_debug_checks)
350 b->expensive_debug_checks = expensive_debug_checks;
352 b->last_set_unwritten = 0;
354 /* XXX: shouldn't be needed */
355 for (i = 0; i < MAX_BSETS; i++)
358 * Second loop starts at 1 because b->keys[0]->data is the memory we
361 for (i = 1; i < MAX_BSETS; i++)
362 b->set[i].data = NULL;
364 EXPORT_SYMBOL(bch_btree_keys_init);
366 /* Binary tree stuff for auxiliary search trees */
368 static unsigned inorder_next(unsigned j, unsigned size)
370 if (j * 2 + 1 < size) {
381 static unsigned inorder_prev(unsigned j, unsigned size)
386 while (j * 2 + 1 < size)
394 /* I have no idea why this code works... and I'm the one who wrote it
396 * However, I do know what it does:
397 * Given a binary tree constructed in an array (i.e. how you normally implement
398 * a heap), it converts a node in the tree - referenced by array index - to the
399 * index it would have if you did an inorder traversal.
401 * Also tested for every j, size up to size somewhere around 6 million.
403 * The binary tree starts at array index 1, not 0
404 * extra is a function of size:
405 * extra = (size - rounddown_pow_of_two(size - 1)) << 1;
407 static unsigned __to_inorder(unsigned j, unsigned size, unsigned extra)
410 unsigned shift = fls(size - 1) - b;
418 j -= (j - extra) >> 1;
423 static unsigned to_inorder(unsigned j, struct bset_tree *t)
425 return __to_inorder(j, t->size, t->extra);
428 static unsigned __inorder_to_tree(unsigned j, unsigned size, unsigned extra)
438 j |= roundup_pow_of_two(size) >> shift;
443 static unsigned inorder_to_tree(unsigned j, struct bset_tree *t)
445 return __inorder_to_tree(j, t->size, t->extra);
449 void inorder_test(void)
451 unsigned long done = 0;
452 ktime_t start = ktime_get();
454 for (unsigned size = 2;
457 unsigned extra = (size - rounddown_pow_of_two(size - 1)) << 1;
458 unsigned i = 1, j = rounddown_pow_of_two(size - 1);
461 printk(KERN_NOTICE "loop %u, %llu per us\n", size,
462 done / ktime_us_delta(ktime_get(), start));
465 if (__inorder_to_tree(i, size, extra) != j)
466 panic("size %10u j %10u i %10u", size, j, i);
468 if (__to_inorder(j, size, extra) != i)
469 panic("size %10u j %10u i %10u", size, j, i);
471 if (j == rounddown_pow_of_two(size) - 1)
474 BUG_ON(inorder_prev(inorder_next(j, size), size) != j);
476 j = inorder_next(j, size);
486 * Cacheline/offset <-> bkey pointer arithmetic:
488 * t->tree is a binary search tree in an array; each node corresponds to a key
489 * in one cacheline in t->set (BSET_CACHELINE bytes).
491 * This means we don't have to store the full index of the key that a node in
492 * the binary tree points to; to_inorder() gives us the cacheline, and then
493 * bkey_float->m gives us the offset within that cacheline, in units of 8 bytes.
495 * cacheline_to_bkey() and friends abstract out all the pointer arithmetic to
498 * To construct the bfloat for an arbitrary key we need to know what the key
499 * immediately preceding it is: we have to check if the two keys differ in the
500 * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size
501 * of the previous key so we can walk backwards to it from t->tree[j]'s key.
504 static struct bkey *cacheline_to_bkey(struct bset_tree *t, unsigned cacheline,
507 return ((void *) t->data) + cacheline * BSET_CACHELINE + offset * 8;
510 static unsigned bkey_to_cacheline(struct bset_tree *t, struct bkey *k)
512 return ((void *) k - (void *) t->data) / BSET_CACHELINE;
515 static unsigned bkey_to_cacheline_offset(struct bset_tree *t,
519 return (u64 *) k - (u64 *) cacheline_to_bkey(t, cacheline, 0);
522 static struct bkey *tree_to_bkey(struct bset_tree *t, unsigned j)
524 return cacheline_to_bkey(t, to_inorder(j, t), t->tree[j].m);
527 static struct bkey *tree_to_prev_bkey(struct bset_tree *t, unsigned j)
529 return (void *) (((uint64_t *) tree_to_bkey(t, j)) - t->prev[j]);
533 * For the write set - the one we're currently inserting keys into - we don't
534 * maintain a full search tree, we just keep a simple lookup table in t->prev.
536 static struct bkey *table_to_bkey(struct bset_tree *t, unsigned cacheline)
538 return cacheline_to_bkey(t, cacheline, t->prev[cacheline]);
541 static inline uint64_t shrd128(uint64_t high, uint64_t low, uint8_t shift)
544 low |= (high << 1) << (63U - shift);
548 static inline unsigned bfloat_mantissa(const struct bkey *k,
549 struct bkey_float *f)
551 const uint64_t *p = &k->low - (f->exponent >> 6);
552 return shrd128(p[-1], p[0], f->exponent & 63) & BKEY_MANTISSA_MASK;
555 static void make_bfloat(struct bset_tree *t, unsigned j)
557 struct bkey_float *f = &t->tree[j];
558 struct bkey *m = tree_to_bkey(t, j);
559 struct bkey *p = tree_to_prev_bkey(t, j);
561 struct bkey *l = is_power_of_2(j)
563 : tree_to_prev_bkey(t, j >> ffs(j));
565 struct bkey *r = is_power_of_2(j + 1)
566 ? bset_bkey_idx(t->data, t->data->keys - bkey_u64s(&t->end))
567 : tree_to_bkey(t, j >> (ffz(j) + 1));
569 BUG_ON(m < l || m > r);
570 BUG_ON(bkey_next(p) != m);
572 if (KEY_INODE(l) != KEY_INODE(r))
573 f->exponent = fls64(KEY_INODE(r) ^ KEY_INODE(l)) + 64;
575 f->exponent = fls64(r->low ^ l->low);
577 f->exponent = max_t(int, f->exponent - BKEY_MANTISSA_BITS, 0);
580 * Setting f->exponent = 127 flags this node as failed, and causes the
581 * lookup code to fall back to comparing against the original key.
584 if (bfloat_mantissa(m, f) != bfloat_mantissa(p, f))
585 f->mantissa = bfloat_mantissa(m, f) - 1;
590 static void bset_alloc_tree(struct btree_keys *b, struct bset_tree *t)
593 unsigned j = roundup(t[-1].size,
594 64 / sizeof(struct bkey_float));
596 t->tree = t[-1].tree + j;
597 t->prev = t[-1].prev + j;
600 while (t < b->set + MAX_BSETS)
604 static void bch_bset_build_unwritten_tree(struct btree_keys *b)
606 struct bset_tree *t = bset_tree_last(b);
608 BUG_ON(b->last_set_unwritten);
609 b->last_set_unwritten = 1;
611 bset_alloc_tree(b, t);
613 if (t->tree != b->set->tree + btree_keys_cachelines(b)) {
614 t->prev[0] = bkey_to_cacheline_offset(t, 0, t->data->start);
619 void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
621 if (i != b->set->data) {
622 b->set[++b->nsets].data = i;
623 i->seq = b->set->data->seq;
625 get_random_bytes(&i->seq, sizeof(uint64_t));
631 bch_bset_build_unwritten_tree(b);
633 EXPORT_SYMBOL(bch_bset_init_next);
635 void bch_bset_build_written_tree(struct btree_keys *b)
637 struct bset_tree *t = bset_tree_last(b);
638 struct bkey *prev = NULL, *k = t->data->start;
639 unsigned j, cacheline = 1;
641 b->last_set_unwritten = 0;
643 bset_alloc_tree(b, t);
645 t->size = min_t(unsigned,
646 bkey_to_cacheline(t, bset_bkey_last(t->data)),
647 b->set->tree + btree_keys_cachelines(b) - t->tree);
654 t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1;
656 /* First we figure out where the first key in each cacheline is */
657 for (j = inorder_next(0, t->size);
659 j = inorder_next(j, t->size)) {
660 while (bkey_to_cacheline(t, k) < cacheline)
661 prev = k, k = bkey_next(k);
663 t->prev[j] = bkey_u64s(prev);
664 t->tree[j].m = bkey_to_cacheline_offset(t, cacheline++, k);
667 while (bkey_next(k) != bset_bkey_last(t->data))
672 /* Then we build the tree */
673 for (j = inorder_next(0, t->size);
675 j = inorder_next(j, t->size))
678 EXPORT_SYMBOL(bch_bset_build_written_tree);
682 void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k)
685 unsigned inorder, j = 1;
687 for (t = b->set; t <= bset_tree_last(b); t++)
688 if (k < bset_bkey_last(t->data))
693 if (!t->size || !bset_written(b, t))
696 inorder = bkey_to_cacheline(t, k);
698 if (k == t->data->start)
701 if (bkey_next(k) == bset_bkey_last(t->data)) {
706 j = inorder_to_tree(inorder, t);
710 k == tree_to_bkey(t, j))
714 } while (j < t->size);
716 j = inorder_to_tree(inorder + 1, t);
720 k == tree_to_prev_bkey(t, j))
724 } while (j < t->size);
726 EXPORT_SYMBOL(bch_bset_fix_invalidated_key);
728 static void bch_bset_fix_lookup_table(struct btree_keys *b,
732 unsigned shift = bkey_u64s(k);
733 unsigned j = bkey_to_cacheline(t, k);
735 /* We're getting called from btree_split() or btree_gc, just bail out */
739 /* k is the key we just inserted; we need to find the entry in the
740 * lookup table for the first key that is strictly greater than k:
741 * it's either k's cacheline or the next one
743 while (j < t->size &&
744 table_to_bkey(t, j) <= k)
747 /* Adjust all the lookup table entries, and find a new key for any that
748 * have gotten too big
750 for (; j < t->size; j++) {
753 if (t->prev[j] > 7) {
754 k = table_to_bkey(t, j - 1);
756 while (k < cacheline_to_bkey(t, j, 0))
759 t->prev[j] = bkey_to_cacheline_offset(t, j, k);
763 if (t->size == b->set->tree + btree_keys_cachelines(b) - t->tree)
766 /* Possibly add a new entry to the end of the lookup table */
768 for (k = table_to_bkey(t, t->size - 1);
769 k != bset_bkey_last(t->data);
771 if (t->size == bkey_to_cacheline(t, k)) {
772 t->prev[t->size] = bkey_to_cacheline_offset(t, t->size, k);
778 * Tries to merge l and r: l should be lower than r
779 * Returns true if we were able to merge. If we did merge, l will be the merged
780 * key, r will be untouched.
782 bool bch_bkey_try_merge(struct btree_keys *b, struct bkey *l, struct bkey *r)
784 if (!b->ops->key_merge)
788 * Generic header checks
789 * Assumes left and right are in order
790 * Left and right must be exactly aligned
792 if (!bch_bkey_equal_header(l, r) ||
793 bkey_cmp(l, &START_KEY(r)))
796 return b->ops->key_merge(b, l, r);
798 EXPORT_SYMBOL(bch_bkey_try_merge);
800 void bch_bset_insert(struct btree_keys *b, struct bkey *where,
803 struct bset_tree *t = bset_tree_last(b);
805 BUG_ON(!b->last_set_unwritten);
806 BUG_ON(bset_byte_offset(b, t->data) +
807 __set_bytes(t->data, t->data->keys + bkey_u64s(insert)) >
808 PAGE_SIZE << b->page_order);
810 memmove((uint64_t *) where + bkey_u64s(insert),
812 (void *) bset_bkey_last(t->data) - (void *) where);
814 t->data->keys += bkey_u64s(insert);
815 bkey_copy(where, insert);
816 bch_bset_fix_lookup_table(b, t, where);
818 EXPORT_SYMBOL(bch_bset_insert);
820 unsigned bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
821 struct bkey *replace_key)
823 unsigned status = BTREE_INSERT_STATUS_NO_INSERT;
824 struct bset *i = bset_tree_last(b)->data;
825 struct bkey *m, *prev = NULL;
826 struct btree_iter iter;
828 BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
830 m = bch_btree_iter_init(b, &iter, b->ops->is_extents
831 ? PRECEDING_KEY(&START_KEY(k))
834 if (b->ops->insert_fixup(b, k, &iter, replace_key))
837 status = BTREE_INSERT_STATUS_INSERT;
839 while (m != bset_bkey_last(i) &&
840 bkey_cmp(k, b->ops->is_extents ? &START_KEY(m) : m) > 0)
841 prev = m, m = bkey_next(m);
843 /* prev is in the tree, if we merge we're done */
844 status = BTREE_INSERT_STATUS_BACK_MERGE;
846 bch_bkey_try_merge(b, prev, k))
849 status = BTREE_INSERT_STATUS_OVERWROTE;
850 if (m != bset_bkey_last(i) &&
851 KEY_PTRS(m) == KEY_PTRS(k) && !KEY_SIZE(m))
854 status = BTREE_INSERT_STATUS_FRONT_MERGE;
855 if (m != bset_bkey_last(i) &&
856 bch_bkey_try_merge(b, k, m))
859 bch_bset_insert(b, m, k);
860 copy: bkey_copy(m, k);
864 EXPORT_SYMBOL(bch_btree_insert_key);
868 struct bset_search_iter {
872 static struct bset_search_iter bset_search_write_set(struct bset_tree *t,
873 const struct bkey *search)
875 unsigned li = 0, ri = t->size;
877 while (li + 1 != ri) {
878 unsigned m = (li + ri) >> 1;
880 if (bkey_cmp(table_to_bkey(t, m), search) > 0)
886 return (struct bset_search_iter) {
887 table_to_bkey(t, li),
888 ri < t->size ? table_to_bkey(t, ri) : bset_bkey_last(t->data)
892 static struct bset_search_iter bset_search_tree(struct bset_tree *t,
893 const struct bkey *search)
896 struct bkey_float *f;
897 unsigned inorder, j, n = 1;
901 p &= ((int) (p - t->size)) >> 31;
903 prefetch(&t->tree[p]);
909 * n = (f->mantissa > bfloat_mantissa())
913 * We need to subtract 1 from f->mantissa for the sign bit trick
914 * to work - that's done in make_bfloat()
916 if (likely(f->exponent != 127))
917 n = j * 2 + (((unsigned)
919 bfloat_mantissa(search, f))) >> 31);
921 n = (bkey_cmp(tree_to_bkey(t, j), search) > 0)
924 } while (n < t->size);
926 inorder = to_inorder(j, t);
929 * n would have been the node we recursed to - the low bit tells us if
930 * we recursed left or recursed right.
933 l = cacheline_to_bkey(t, inorder, f->m);
935 if (++inorder != t->size) {
936 f = &t->tree[inorder_next(j, t->size)];
937 r = cacheline_to_bkey(t, inorder, f->m);
939 r = bset_bkey_last(t->data);
941 r = cacheline_to_bkey(t, inorder, f->m);
944 f = &t->tree[inorder_prev(j, t->size)];
945 l = cacheline_to_bkey(t, inorder, f->m);
950 return (struct bset_search_iter) {l, r};
953 struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
954 const struct bkey *search)
956 struct bset_search_iter i;
959 * First, we search for a cacheline, then lastly we do a linear search
960 * within that cacheline.
962 * To search for the cacheline, there's three different possibilities:
963 * * The set is too small to have a search tree, so we just do a linear
964 * search over the whole set.
965 * * The set is the one we're currently inserting into; keeping a full
966 * auxiliary search tree up to date would be too expensive, so we
967 * use a much simpler lookup table to do a binary search -
968 * bset_search_write_set().
969 * * Or we use the auxiliary search tree we constructed earlier -
973 if (unlikely(!t->size)) {
974 i.l = t->data->start;
975 i.r = bset_bkey_last(t->data);
976 } else if (bset_written(b, t)) {
978 * Each node in the auxiliary search tree covers a certain range
979 * of bits, and keys above and below the set it covers might
980 * differ outside those bits - so we have to special case the
981 * start and end - handle that here:
984 if (unlikely(bkey_cmp(search, &t->end) >= 0))
985 return bset_bkey_last(t->data);
987 if (unlikely(bkey_cmp(search, t->data->start) < 0))
988 return t->data->start;
990 i = bset_search_tree(t, search);
993 t->size < bkey_to_cacheline(t, bset_bkey_last(t->data)));
995 i = bset_search_write_set(t, search);
998 if (btree_keys_expensive_checks(b)) {
999 BUG_ON(bset_written(b, t) &&
1000 i.l != t->data->start &&
1001 bkey_cmp(tree_to_prev_bkey(t,
1002 inorder_to_tree(bkey_to_cacheline(t, i.l), t)),
1005 BUG_ON(i.r != bset_bkey_last(t->data) &&
1006 bkey_cmp(i.r, search) <= 0);
1009 while (likely(i.l != i.r) &&
1010 bkey_cmp(i.l, search) <= 0)
1011 i.l = bkey_next(i.l);
1015 EXPORT_SYMBOL(__bch_bset_search);
1017 /* Btree iterator */
1019 typedef bool (btree_iter_cmp_fn)(struct btree_iter_set,
1020 struct btree_iter_set);
1022 static inline bool btree_iter_cmp(struct btree_iter_set l,
1023 struct btree_iter_set r)
1025 return bkey_cmp(l.k, r.k) > 0;
1028 static inline bool btree_iter_end(struct btree_iter *iter)
1033 void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
1037 BUG_ON(!heap_add(iter,
1038 ((struct btree_iter_set) { k, end }),
1042 static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
1043 struct btree_iter *iter,
1044 struct bkey *search,
1045 struct bset_tree *start)
1047 struct bkey *ret = NULL;
1048 iter->size = ARRAY_SIZE(iter->data);
1051 #ifdef CONFIG_BCACHE_DEBUG
1055 for (; start <= bset_tree_last(b); start++) {
1056 ret = bch_bset_search(b, start, search);
1057 bch_btree_iter_push(iter, ret, bset_bkey_last(start->data));
1063 struct bkey *bch_btree_iter_init(struct btree_keys *b,
1064 struct btree_iter *iter,
1065 struct bkey *search)
1067 return __bch_btree_iter_init(b, iter, search, b->set);
1069 EXPORT_SYMBOL(bch_btree_iter_init);
1071 static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
1072 btree_iter_cmp_fn *cmp)
1074 struct btree_iter_set unused;
1075 struct bkey *ret = NULL;
1077 if (!btree_iter_end(iter)) {
1078 bch_btree_iter_next_check(iter);
1080 ret = iter->data->k;
1081 iter->data->k = bkey_next(iter->data->k);
1083 if (iter->data->k > iter->data->end) {
1084 WARN_ONCE(1, "bset was corrupt!\n");
1085 iter->data->k = iter->data->end;
1088 if (iter->data->k == iter->data->end)
1089 heap_pop(iter, unused, cmp);
1091 heap_sift(iter, 0, cmp);
1097 struct bkey *bch_btree_iter_next(struct btree_iter *iter)
1099 return __bch_btree_iter_next(iter, btree_iter_cmp);
1102 EXPORT_SYMBOL(bch_btree_iter_next);
1104 struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,
1105 struct btree_keys *b, ptr_filter_fn fn)
1110 ret = bch_btree_iter_next(iter);
1111 } while (ret && fn(b, ret));
1118 void bch_bset_sort_state_free(struct bset_sort_state *state)
1121 mempool_destroy(state->pool);
1124 int bch_bset_sort_state_init(struct bset_sort_state *state, unsigned page_order)
1126 spin_lock_init(&state->time.lock);
1128 state->page_order = page_order;
1129 state->crit_factor = int_sqrt(1 << page_order);
1131 state->pool = mempool_create_page_pool(1, page_order);
1137 EXPORT_SYMBOL(bch_bset_sort_state_init);
1139 static void btree_mergesort(struct btree_keys *b, struct bset *out,
1140 struct btree_iter *iter,
1141 bool fixup, bool remove_stale)
1144 struct bkey *k, *last = NULL;
1146 bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale
1150 /* Heapify the iterator, using our comparison function */
1151 for (i = iter->used / 2 - 1; i >= 0; --i)
1152 heap_sift(iter, i, b->ops->sort_cmp);
1154 while (!btree_iter_end(iter)) {
1155 if (b->ops->sort_fixup && fixup)
1156 k = b->ops->sort_fixup(iter, &tmp.k);
1161 k = __bch_btree_iter_next(iter, b->ops->sort_cmp);
1169 } else if (!bch_bkey_try_merge(b, last, k)) {
1170 last = bkey_next(last);
1175 out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0;
1177 pr_debug("sorted %i keys", out->keys);
1180 static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
1181 unsigned start, unsigned order, bool fixup,
1182 struct bset_sort_state *state)
1184 uint64_t start_time;
1185 bool used_mempool = false;
1186 struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOWAIT,
1191 BUG_ON(order > state->page_order);
1193 outp = mempool_alloc(state->pool, GFP_NOIO);
1194 out = page_address(outp);
1195 used_mempool = true;
1196 order = state->page_order;
1199 start_time = local_clock();
1201 btree_mergesort(b, out, iter, fixup, false);
1204 if (!start && order == b->page_order) {
1206 * Our temporary buffer is the same size as the btree node's
1207 * buffer, we can just swap buffers instead of doing a big
1211 out->magic = b->set->data->magic;
1212 out->seq = b->set->data->seq;
1213 out->version = b->set->data->version;
1214 swap(out, b->set->data);
1216 b->set[start].data->keys = out->keys;
1217 memcpy(b->set[start].data->start, out->start,
1218 (void *) bset_bkey_last(out) - (void *) out->start);
1222 mempool_free(virt_to_page(out), state->pool);
1224 free_pages((unsigned long) out, order);
1226 bch_bset_build_written_tree(b);
1229 bch_time_stats_update(&state->time, start_time);
1232 void bch_btree_sort_partial(struct btree_keys *b, unsigned start,
1233 struct bset_sort_state *state)
1235 size_t order = b->page_order, keys = 0;
1236 struct btree_iter iter;
1237 int oldsize = bch_count_data(b);
1239 __bch_btree_iter_init(b, &iter, NULL, &b->set[start]);
1244 for (i = start; i <= b->nsets; i++)
1245 keys += b->set[i].data->keys;
1247 order = get_order(__set_bytes(b->set->data, keys));
1250 __btree_sort(b, &iter, start, order, false, state);
1252 EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize);
1254 EXPORT_SYMBOL(bch_btree_sort_partial);
1256 void bch_btree_sort_and_fix_extents(struct btree_keys *b,
1257 struct btree_iter *iter,
1258 struct bset_sort_state *state)
1260 __btree_sort(b, iter, 0, b->page_order, true, state);
1263 void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new,
1264 struct bset_sort_state *state)
1266 uint64_t start_time = local_clock();
1268 struct btree_iter iter;
1269 bch_btree_iter_init(b, &iter, NULL);
1271 btree_mergesort(b, new->set->data, &iter, false, true);
1273 bch_time_stats_update(&state->time, start_time);
1275 new->set->size = 0; // XXX: why?
1278 #define SORT_CRIT (4096 / sizeof(uint64_t))
1280 void bch_btree_sort_lazy(struct btree_keys *b, struct bset_sort_state *state)
1282 unsigned crit = SORT_CRIT;
1285 /* Don't sort if nothing to do */
1289 for (i = b->nsets - 1; i >= 0; --i) {
1290 crit *= state->crit_factor;
1292 if (b->set[i].data->keys < crit) {
1293 bch_btree_sort_partial(b, i, state);
1298 /* Sort if we'd overflow */
1299 if (b->nsets + 1 == MAX_BSETS) {
1300 bch_btree_sort(b, state);
1305 bch_bset_build_written_tree(b);
1307 EXPORT_SYMBOL(bch_btree_sort_lazy);
1309 void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats)
1313 for (i = 0; i <= b->nsets; i++) {
1314 struct bset_tree *t = &b->set[i];
1315 size_t bytes = t->data->keys * sizeof(uint64_t);
1318 if (bset_written(b, t)) {
1319 stats->sets_written++;
1320 stats->bytes_written += bytes;
1322 stats->floats += t->size - 1;
1324 for (j = 1; j < t->size; j++)
1325 if (t->tree[j].exponent == 127)
1328 stats->sets_unwritten++;
1329 stats->bytes_unwritten += bytes;