/* * Code for working with individual keys, and sorted sets of keys with in a * btree node * * Copyright 2012 Google, Inc. */ #include "bcache.h" #include "btree.h" #include "debug.h" #include #include /* Keylists */ void bch_keylist_copy(struct keylist *dest, struct keylist *src) { *dest = *src; if (src->list == src->d) { size_t n = (uint64_t *) src->top - src->d; dest->top = (struct bkey *) &dest->d[n]; dest->list = dest->d; } } int bch_keylist_realloc(struct keylist *l, int nptrs, struct cache_set *c) { unsigned oldsize = (uint64_t *) l->top - l->list; unsigned newsize = oldsize + 2 + nptrs; uint64_t *new; /* The journalling code doesn't handle the case where the keys to insert * is bigger than an empty write: If we just return -ENOMEM here, * bio_insert() and bio_invalidate() will insert the keys created so far * and finish the rest when the keylist is empty. */ if (newsize * sizeof(uint64_t) > block_bytes(c) - sizeof(struct jset)) return -ENOMEM; newsize = roundup_pow_of_two(newsize); if (newsize <= KEYLIST_INLINE || roundup_pow_of_two(oldsize) == newsize) return 0; new = krealloc(l->list == l->d ? NULL : l->list, sizeof(uint64_t) * newsize, GFP_NOIO); if (!new) return -ENOMEM; if (l->list == l->d) memcpy(new, l->list, sizeof(uint64_t) * KEYLIST_INLINE); l->list = new; l->top = (struct bkey *) (&l->list[oldsize]); return 0; } struct bkey *bch_keylist_pop(struct keylist *l) { struct bkey *k = l->bottom; if (k == l->top) return NULL; while (bkey_next(k) != l->top) k = bkey_next(k); return l->top = k; } /* Pointer validation */ bool __bch_ptr_invalid(struct cache_set *c, int level, const struct bkey *k) { unsigned i; if (level && (!KEY_PTRS(k) || !KEY_SIZE(k) || KEY_DIRTY(k))) goto bad; if (!level && KEY_SIZE(k) > KEY_OFFSET(k)) goto bad; if (!KEY_SIZE(k)) return true; for (i = 0; i < KEY_PTRS(k); i++) if (ptr_available(c, k, i)) { struct cache *ca = PTR_CACHE(c, k, i); size_t bucket = PTR_BUCKET_NR(c, k, i); size_t r = bucket_remainder(c, PTR_OFFSET(k, i)); if (KEY_SIZE(k) + r > c->sb.bucket_size || bucket < ca->sb.first_bucket || bucket >= ca->sb.nbuckets) goto bad; } return false; bad: cache_bug(c, "spotted bad key %s: %s", pkey(k), bch_ptr_status(c, k)); return true; } bool bch_ptr_bad(struct btree *b, const struct bkey *k) { struct bucket *g; unsigned i, stale; if (!bkey_cmp(k, &ZERO_KEY) || !KEY_PTRS(k) || bch_ptr_invalid(b, k)) return true; if (KEY_PTRS(k) && PTR_DEV(k, 0) == PTR_CHECK_DEV) return true; for (i = 0; i < KEY_PTRS(k); i++) if (ptr_available(b->c, k, i)) { g = PTR_BUCKET(b->c, k, i); stale = ptr_stale(b->c, k, i); btree_bug_on(stale > 96, b, "key too stale: %i, need_gc %u", stale, b->c->need_gc); btree_bug_on(stale && KEY_DIRTY(k) && KEY_SIZE(k), b, "stale dirty pointer"); if (stale) return true; #ifdef CONFIG_BCACHE_EDEBUG if (!mutex_trylock(&b->c->bucket_lock)) continue; if (b->level) { if (KEY_DIRTY(k) || g->prio != BTREE_PRIO || (b->c->gc_mark_valid && GC_MARK(g) != GC_MARK_METADATA)) goto bug; } else { if (g->prio == BTREE_PRIO) goto bug; if (KEY_DIRTY(k) && b->c->gc_mark_valid && GC_MARK(g) != GC_MARK_DIRTY) goto bug; } mutex_unlock(&b->c->bucket_lock); #endif } return false; #ifdef CONFIG_BCACHE_EDEBUG bug: mutex_unlock(&b->c->bucket_lock); btree_bug(b, "inconsistent pointer %s: bucket %zu pin %i prio %i gen %i last_gc %i mark %llu gc_gen %i", pkey(k), PTR_BUCKET_NR(b->c, k, i), atomic_read(&g->pin), g->prio, g->gen, g->last_gc, GC_MARK(g), g->gc_gen); return true; #endif } /* Key/pointer manipulation */ void bch_bkey_copy_single_ptr(struct bkey *dest, const struct bkey *src, unsigned i) { BUG_ON(i > KEY_PTRS(src)); /* Only copy the header, key, and one pointer. */ memcpy(dest, src, 2 * sizeof(uint64_t)); dest->ptr[0] = src->ptr[i]; SET_KEY_PTRS(dest, 1); /* We didn't copy the checksum so clear that bit. */ SET_KEY_CSUM(dest, 0); } bool __bch_cut_front(const struct bkey *where, struct bkey *k) { unsigned i, len = 0; if (bkey_cmp(where, &START_KEY(k)) <= 0) return false; if (bkey_cmp(where, k) < 0) len = KEY_OFFSET(k) - KEY_OFFSET(where); else bkey_copy_key(k, where); for (i = 0; i < KEY_PTRS(k); i++) SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + KEY_SIZE(k) - len); BUG_ON(len > KEY_SIZE(k)); SET_KEY_SIZE(k, len); return true; } bool __bch_cut_back(const struct bkey *where, struct bkey *k) { unsigned len = 0; if (bkey_cmp(where, k) >= 0) return false; BUG_ON(KEY_INODE(where) != KEY_INODE(k)); if (bkey_cmp(where, &START_KEY(k)) > 0) len = KEY_OFFSET(where) - KEY_START(k); bkey_copy_key(k, where); BUG_ON(len > KEY_SIZE(k)); SET_KEY_SIZE(k, len); return true; } static uint64_t merge_chksums(struct bkey *l, struct bkey *r) { return (l->ptr[KEY_PTRS(l)] + r->ptr[KEY_PTRS(r)]) & ~((uint64_t)1 << 63); } /* Tries to merge l and r: l should be lower than r * Returns true if we were able to merge. If we did merge, l will be the merged * key, r will be untouched. */ bool bch_bkey_try_merge(struct btree *b, struct bkey *l, struct bkey *r) { unsigned i; if (key_merging_disabled(b->c)) return false; if (KEY_PTRS(l) != KEY_PTRS(r) || KEY_DIRTY(l) != KEY_DIRTY(r) || bkey_cmp(l, &START_KEY(r))) return false; for (i = 0; i < KEY_PTRS(l); i++) if (l->ptr[i] + PTR(0, KEY_SIZE(l), 0) != r->ptr[i] || PTR_BUCKET_NR(b->c, l, i) != PTR_BUCKET_NR(b->c, r, i)) return false; /* Keys with no pointers aren't restricted to one bucket and could * overflow KEY_SIZE */ if (KEY_SIZE(l) + KEY_SIZE(r) > USHRT_MAX) { SET_KEY_OFFSET(l, KEY_OFFSET(l) + USHRT_MAX - KEY_SIZE(l)); SET_KEY_SIZE(l, USHRT_MAX); bch_cut_front(l, r); return false; } if (KEY_CSUM(l)) { if (KEY_CSUM(r)) l->ptr[KEY_PTRS(l)] = merge_chksums(l, r); else SET_KEY_CSUM(l, 0); } SET_KEY_OFFSET(l, KEY_OFFSET(l) + KEY_SIZE(r)); SET_KEY_SIZE(l, KEY_SIZE(l) + KEY_SIZE(r)); return true; } /* Binary tree stuff for auxiliary search trees */ static unsigned inorder_next(unsigned j, unsigned size) { if (j * 2 + 1 < size) { j = j * 2 + 1; while (j * 2 < size) j *= 2; } else j >>= ffz(j) + 1; return j; } static unsigned inorder_prev(unsigned j, unsigned size) { if (j * 2 < size) { j = j * 2; while (j * 2 + 1 < size) j = j * 2 + 1; } else j >>= ffs(j); return j; } /* I have no idea why this code works... and I'm the one who wrote it * * However, I do know what it does: * Given a binary tree constructed in an array (i.e. how you normally implement * a heap), it converts a node in the tree - referenced by array index - to the * index it would have if you did an inorder traversal. * * Also tested for every j, size up to size somewhere around 6 million. * * The binary tree starts at array index 1, not 0 * extra is a function of size: * extra = (size - rounddown_pow_of_two(size - 1)) << 1; */ static unsigned __to_inorder(unsigned j, unsigned size, unsigned extra) { unsigned b = fls(j); unsigned shift = fls(size - 1) - b; j ^= 1U << (b - 1); j <<= 1; j |= 1; j <<= shift; if (j > extra) j -= (j - extra) >> 1; return j; } static unsigned to_inorder(unsigned j, struct bset_tree *t) { return __to_inorder(j, t->size, t->extra); } static unsigned __inorder_to_tree(unsigned j, unsigned size, unsigned extra) { unsigned shift; if (j > extra) j += j - extra; shift = ffs(j); j >>= shift; j |= roundup_pow_of_two(size) >> shift; return j; } static unsigned inorder_to_tree(unsigned j, struct bset_tree *t) { return __inorder_to_tree(j, t->size, t->extra); } #if 0 void inorder_test(void) { unsigned long done = 0; ktime_t start = ktime_get(); for (unsigned size = 2; size < 65536000; size++) { unsigned extra = (size - rounddown_pow_of_two(size - 1)) << 1; unsigned i = 1, j = rounddown_pow_of_two(size - 1); if (!(size % 4096)) printk(KERN_NOTICE "loop %u, %llu per us\n", size, done / ktime_us_delta(ktime_get(), start)); while (1) { if (__inorder_to_tree(i, size, extra) != j) panic("size %10u j %10u i %10u", size, j, i); if (__to_inorder(j, size, extra) != i) panic("size %10u j %10u i %10u", size, j, i); if (j == rounddown_pow_of_two(size) - 1) break; BUG_ON(inorder_prev(inorder_next(j, size), size) != j); j = inorder_next(j, size); i++; } done += size - 1; } } #endif /* * Cacheline/offset <-> bkey pointer arithmatic: * * t->tree is a binary search tree in an array; each node corresponds to a key * in one cacheline in t->set (BSET_CACHELINE bytes). * * This means we don't have to store the full index of the key that a node in * the binary tree points to; to_inorder() gives us the cacheline, and then * bkey_float->m gives us the offset within that cacheline, in units of 8 bytes. * * cacheline_to_bkey() and friends abstract out all the pointer arithmatic to * make this work. * * To construct the bfloat for an arbitrary key we need to know what the key * immediately preceding it is: we have to check if the two keys differ in the * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size * of the previous key so we can walk backwards to it from t->tree[j]'s key. */ static struct bkey *cacheline_to_bkey(struct bset_tree *t, unsigned cacheline, unsigned offset) { return ((void *) t->data) + cacheline * BSET_CACHELINE + offset * 8; } static unsigned bkey_to_cacheline(struct bset_tree *t, struct bkey *k) { return ((void *) k - (void *) t->data) / BSET_CACHELINE; } static unsigned bkey_to_cacheline_offset(struct bkey *k) { return ((size_t) k & (BSET_CACHELINE - 1)) / sizeof(uint64_t); } static struct bkey *tree_to_bkey(struct bset_tree *t, unsigned j) { return cacheline_to_bkey(t, to_inorder(j, t), t->tree[j].m); } static struct bkey *tree_to_prev_bkey(struct bset_tree *t, unsigned j) { return (void *) (((uint64_t *) tree_to_bkey(t, j)) - t->prev[j]); } /* * For the write set - the one we're currently inserting keys into - we don't * maintain a full search tree, we just keep a simple lookup table in t->prev. */ static struct bkey *table_to_bkey(struct bset_tree *t, unsigned cacheline) { return cacheline_to_bkey(t, cacheline, t->prev[cacheline]); } static inline uint64_t shrd128(uint64_t high, uint64_t low, uint8_t shift) { #ifdef CONFIG_X86_64 asm("shrd %[shift],%[high],%[low]" : [low] "+Rm" (low) : [high] "R" (high), [shift] "ci" (shift) : "cc"); #else low >>= shift; low |= (high << 1) << (63U - shift); #endif return low; } static inline unsigned bfloat_mantissa(const struct bkey *k, struct bkey_float *f) { const uint64_t *p = &k->low - (f->exponent >> 6); return shrd128(p[-1], p[0], f->exponent & 63) & BKEY_MANTISSA_MASK; } static void make_bfloat(struct bset_tree *t, unsigned j) { struct bkey_float *f = &t->tree[j]; struct bkey *m = tree_to_bkey(t, j); struct bkey *p = tree_to_prev_bkey(t, j); struct bkey *l = is_power_of_2(j) ? t->data->start : tree_to_prev_bkey(t, j >> ffs(j)); struct bkey *r = is_power_of_2(j + 1) ? node(t->data, t->data->keys - bkey_u64s(&t->end)) : tree_to_bkey(t, j >> (ffz(j) + 1)); BUG_ON(m < l || m > r); BUG_ON(bkey_next(p) != m); if (KEY_INODE(l) != KEY_INODE(r)) f->exponent = fls64(KEY_INODE(r) ^ KEY_INODE(l)) + 64; else f->exponent = fls64(r->low ^ l->low); f->exponent = max_t(int, f->exponent - BKEY_MANTISSA_BITS, 0); /* * Setting f->exponent = 127 flags this node as failed, and causes the * lookup code to fall back to comparing against the original key. */ if (bfloat_mantissa(m, f) != bfloat_mantissa(p, f)) f->mantissa = bfloat_mantissa(m, f) - 1; else f->exponent = 127; } static void bset_alloc_tree(struct btree *b, struct bset_tree *t) { if (t != b->sets) { unsigned j = roundup(t[-1].size, 64 / sizeof(struct bkey_float)); t->tree = t[-1].tree + j; t->prev = t[-1].prev + j; } while (t < b->sets + MAX_BSETS) t++->size = 0; } static void bset_build_unwritten_tree(struct btree *b) { struct bset_tree *t = b->sets + b->nsets; bset_alloc_tree(b, t); if (t->tree != b->sets->tree + bset_tree_space(b)) { t->prev[0] = bkey_to_cacheline_offset(t->data->start); t->size = 1; } } static void bset_build_written_tree(struct btree *b) { struct bset_tree *t = b->sets + b->nsets; struct bkey *k = t->data->start; unsigned j, cacheline = 1; bset_alloc_tree(b, t); t->size = min_t(unsigned, bkey_to_cacheline(t, end(t->data)), b->sets->tree + bset_tree_space(b) - t->tree); if (t->size < 2) { t->size = 0; return; } t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1; /* First we figure out where the first key in each cacheline is */ for (j = inorder_next(0, t->size); j; j = inorder_next(j, t->size)) { while (bkey_to_cacheline(t, k) != cacheline) k = bkey_next(k); t->prev[j] = bkey_u64s(k); k = bkey_next(k); cacheline++; t->tree[j].m = bkey_to_cacheline_offset(k); } while (bkey_next(k) != end(t->data)) k = bkey_next(k); t->end = *k; /* Then we build the tree */ for (j = inorder_next(0, t->size); j; j = inorder_next(j, t->size)) make_bfloat(t, j); } void bch_bset_fix_invalidated_key(struct btree *b, struct bkey *k) { struct bset_tree *t; unsigned inorder, j = 1; for (t = b->sets; t <= &b->sets[b->nsets]; t++) if (k < end(t->data)) goto found_set; BUG(); found_set: if (!t->size || !bset_written(b, t)) return; inorder = bkey_to_cacheline(t, k); if (k == t->data->start) goto fix_left; if (bkey_next(k) == end(t->data)) { t->end = *k; goto fix_right; } j = inorder_to_tree(inorder, t); if (j && j < t->size && k == tree_to_bkey(t, j)) fix_left: do { make_bfloat(t, j); j = j * 2; } while (j < t->size); j = inorder_to_tree(inorder + 1, t); if (j && j < t->size && k == tree_to_prev_bkey(t, j)) fix_right: do { make_bfloat(t, j); j = j * 2 + 1; } while (j < t->size); } void bch_bset_fix_lookup_table(struct btree *b, struct bkey *k) { struct bset_tree *t = &b->sets[b->nsets]; unsigned shift = bkey_u64s(k); unsigned j = bkey_to_cacheline(t, k); /* We're getting called from btree_split() or btree_gc, just bail out */ if (!t->size) return; /* k is the key we just inserted; we need to find the entry in the * lookup table for the first key that is strictly greater than k: * it's either k's cacheline or the next one */ if (j < t->size && table_to_bkey(t, j) <= k) j++; /* Adjust all the lookup table entries, and find a new key for any that * have gotten too big */ for (; j < t->size; j++) { t->prev[j] += shift; if (t->prev[j] > 7) { k = table_to_bkey(t, j - 1); while (k < cacheline_to_bkey(t, j, 0)) k = bkey_next(k); t->prev[j] = bkey_to_cacheline_offset(k); } } if (t->size == b->sets->tree + bset_tree_space(b) - t->tree) return; /* Possibly add a new entry to the end of the lookup table */ for (k = table_to_bkey(t, t->size - 1); k != end(t->data); k = bkey_next(k)) if (t->size == bkey_to_cacheline(t, k)) { t->prev[t->size] = bkey_to_cacheline_offset(k); t->size++; } } void bch_bset_init_next(struct btree *b) { struct bset *i = write_block(b); if (i != b->sets[0].data) { b->sets[++b->nsets].data = i; i->seq = b->sets[0].data->seq; } else get_random_bytes(&i->seq, sizeof(uint64_t)); i->magic = bset_magic(b->c); i->version = 0; i->keys = 0; bset_build_unwritten_tree(b); } struct bset_search_iter { struct bkey *l, *r; }; static struct bset_search_iter bset_search_write_set(struct btree *b, struct bset_tree *t, const struct bkey *search) { unsigned li = 0, ri = t->size; BUG_ON(!b->nsets && t->size < bkey_to_cacheline(t, end(t->data))); while (li + 1 != ri) { unsigned m = (li + ri) >> 1; if (bkey_cmp(table_to_bkey(t, m), search) > 0) ri = m; else li = m; } return (struct bset_search_iter) { table_to_bkey(t, li), ri < t->size ? table_to_bkey(t, ri) : end(t->data) }; } static struct bset_search_iter bset_search_tree(struct btree *b, struct bset_tree *t, const struct bkey *search) { struct bkey *l, *r; struct bkey_float *f; unsigned inorder, j, n = 1; do { unsigned p = n << 4; p &= ((int) (p - t->size)) >> 31; prefetch(&t->tree[p]); j = n; f = &t->tree[j]; /* * n = (f->mantissa > bfloat_mantissa()) * ? j * 2 * : j * 2 + 1; * * We need to subtract 1 from f->mantissa for the sign bit trick * to work - that's done in make_bfloat() */ if (likely(f->exponent != 127)) n = j * 2 + (((unsigned) (f->mantissa - bfloat_mantissa(search, f))) >> 31); else n = (bkey_cmp(tree_to_bkey(t, j), search) > 0) ? j * 2 : j * 2 + 1; } while (n < t->size); inorder = to_inorder(j, t); /* * n would have been the node we recursed to - the low bit tells us if * we recursed left or recursed right. */ if (n & 1) { l = cacheline_to_bkey(t, inorder, f->m); if (++inorder != t->size) { f = &t->tree[inorder_next(j, t->size)]; r = cacheline_to_bkey(t, inorder, f->m); } else r = end(t->data); } else { r = cacheline_to_bkey(t, inorder, f->m); if (--inorder) { f = &t->tree[inorder_prev(j, t->size)]; l = cacheline_to_bkey(t, inorder, f->m); } else l = t->data->start; } return (struct bset_search_iter) {l, r}; } struct bkey *__bch_bset_search(struct btree *b, struct bset_tree *t, const struct bkey *search) { struct bset_search_iter i; /* * First, we search for a cacheline, then lastly we do a linear search * within that cacheline. * * To search for the cacheline, there's three different possibilities: * * The set is too small to have a search tree, so we just do a linear * search over the whole set. * * The set is the one we're currently inserting into; keeping a full * auxiliary search tree up to date would be too expensive, so we * use a much simpler lookup table to do a binary search - * bset_search_write_set(). * * Or we use the auxiliary search tree we constructed earlier - * bset_search_tree() */ if (unlikely(!t->size)) { i.l = t->data->start; i.r = end(t->data); } else if (bset_written(b, t)) { /* * Each node in the auxiliary search tree covers a certain range * of bits, and keys above and below the set it covers might * differ outside those bits - so we have to special case the * start and end - handle that here: */ if (unlikely(bkey_cmp(search, &t->end) >= 0)) return end(t->data); if (unlikely(bkey_cmp(search, t->data->start) < 0)) return t->data->start; i = bset_search_tree(b, t, search); } else i = bset_search_write_set(b, t, search); #ifdef CONFIG_BCACHE_EDEBUG BUG_ON(bset_written(b, t) && i.l != t->data->start && bkey_cmp(tree_to_prev_bkey(t, inorder_to_tree(bkey_to_cacheline(t, i.l), t)), search) > 0); BUG_ON(i.r != end(t->data) && bkey_cmp(i.r, search) <= 0); #endif while (likely(i.l != i.r) && bkey_cmp(i.l, search) <= 0) i.l = bkey_next(i.l); return i.l; } /* Btree iterator */ static inline bool btree_iter_cmp(struct btree_iter_set l, struct btree_iter_set r) { int64_t c = bkey_cmp(&START_KEY(l.k), &START_KEY(r.k)); return c ? c > 0 : l.k < r.k; } static inline bool btree_iter_end(struct btree_iter *iter) { return !iter->used; } void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k, struct bkey *end) { if (k != end) BUG_ON(!heap_add(iter, ((struct btree_iter_set) { k, end }), btree_iter_cmp)); } struct bkey *__bch_btree_iter_init(struct btree *b, struct btree_iter *iter, struct bkey *search, struct bset_tree *start) { struct bkey *ret = NULL; iter->size = ARRAY_SIZE(iter->data); iter->used = 0; for (; start <= &b->sets[b->nsets]; start++) { ret = bch_bset_search(b, start, search); bch_btree_iter_push(iter, ret, end(start->data)); } return ret; } struct bkey *bch_btree_iter_next(struct btree_iter *iter) { struct btree_iter_set unused; struct bkey *ret = NULL; if (!btree_iter_end(iter)) { ret = iter->data->k; iter->data->k = bkey_next(iter->data->k); if (iter->data->k > iter->data->end) { WARN_ONCE(1, "bset was corrupt!\n"); iter->data->k = iter->data->end; } if (iter->data->k == iter->data->end) heap_pop(iter, unused, btree_iter_cmp); else heap_sift(iter, 0, btree_iter_cmp); } return ret; } struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter, struct btree *b, ptr_filter_fn fn) { struct bkey *ret; do { ret = bch_btree_iter_next(iter); } while (ret && fn(b, ret)); return ret; } struct bkey *bch_next_recurse_key(struct btree *b, struct bkey *search) { struct btree_iter iter; bch_btree_iter_init(b, &iter, search); return bch_btree_iter_next_filter(&iter, b, bch_ptr_bad); } /* Mergesort */ static void sort_key_next(struct btree_iter *iter, struct btree_iter_set *i) { i->k = bkey_next(i->k); if (i->k == i->end) *i = iter->data[--iter->used]; } static struct bkey *btree_sort_fixup(struct btree_iter *iter, struct bkey *tmp) { while (iter->used > 1) { struct btree_iter_set *top = iter->data, *i = top + 1; if (iter->used > 2 && btree_iter_cmp(i[0], i[1])) i++; if (bkey_cmp(top->k, &START_KEY(i->k)) <= 0) break; if (!KEY_SIZE(i->k)) { sort_key_next(iter, i); heap_sift(iter, i - top, btree_iter_cmp); continue; } if (top->k > i->k) { if (bkey_cmp(top->k, i->k) >= 0) sort_key_next(iter, i); else bch_cut_front(top->k, i->k); heap_sift(iter, i - top, btree_iter_cmp); } else { /* can't happen because of comparison func */ BUG_ON(!bkey_cmp(&START_KEY(top->k), &START_KEY(i->k))); if (bkey_cmp(i->k, top->k) < 0) { bkey_copy(tmp, top->k); bch_cut_back(&START_KEY(i->k), tmp); bch_cut_front(i->k, top->k); heap_sift(iter, 0, btree_iter_cmp); return tmp; } else { bch_cut_back(&START_KEY(i->k), top->k); } } } return NULL; } static void btree_mergesort(struct btree *b, struct bset *out, struct btree_iter *iter, bool fixup, bool remove_stale) { struct bkey *k, *last = NULL; BKEY_PADDED(k) tmp; bool (*bad)(struct btree *, const struct bkey *) = remove_stale ? bch_ptr_bad : bch_ptr_invalid; while (!btree_iter_end(iter)) { if (fixup && !b->level) k = btree_sort_fixup(iter, &tmp.k); else k = NULL; if (!k) k = bch_btree_iter_next(iter); if (bad(b, k)) continue; if (!last) { last = out->start; bkey_copy(last, k); } else if (b->level || !bch_bkey_try_merge(b, last, k)) { last = bkey_next(last); bkey_copy(last, k); } } out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0; pr_debug("sorted %i keys", out->keys); bch_check_key_order(b, out); } static void __btree_sort(struct btree *b, struct btree_iter *iter, unsigned start, unsigned order, bool fixup) { uint64_t start_time; bool remove_stale = !b->written; struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOIO, order); if (!out) { mutex_lock(&b->c->sort_lock); out = b->c->sort; order = ilog2(bucket_pages(b->c)); } start_time = local_clock(); btree_mergesort(b, out, iter, fixup, remove_stale); b->nsets = start; if (!fixup && !start && b->written) bch_btree_verify(b, out); if (!start && order == b->page_order) { /* * Our temporary buffer is the same size as the btree node's * buffer, we can just swap buffers instead of doing a big * memcpy() */ out->magic = bset_magic(b->c); out->seq = b->sets[0].data->seq; out->version = b->sets[0].data->version; swap(out, b->sets[0].data); if (b->c->sort == b->sets[0].data) b->c->sort = out; } else { b->sets[start].data->keys = out->keys; memcpy(b->sets[start].data->start, out->start, (void *) end(out) - (void *) out->start); } if (out == b->c->sort) mutex_unlock(&b->c->sort_lock); else free_pages((unsigned long) out, order); if (b->written) bset_build_written_tree(b); if (!start) { spin_lock(&b->c->sort_time_lock); bch_time_stats_update(&b->c->sort_time, start_time); spin_unlock(&b->c->sort_time_lock); } } void bch_btree_sort_partial(struct btree *b, unsigned start) { size_t oldsize = 0, order = b->page_order, keys = 0; struct btree_iter iter; __bch_btree_iter_init(b, &iter, NULL, &b->sets[start]); BUG_ON(b->sets[b->nsets].data == write_block(b) && (b->sets[b->nsets].size || b->nsets)); if (b->written) oldsize = bch_count_data(b); if (start) { unsigned i; for (i = start; i <= b->nsets; i++) keys += b->sets[i].data->keys; order = roundup_pow_of_two(__set_bytes(b->sets->data, keys)) / PAGE_SIZE; if (order) order = ilog2(order); } __btree_sort(b, &iter, start, order, false); EBUG_ON(b->written && bch_count_data(b) != oldsize); } void bch_btree_sort_and_fix_extents(struct btree *b, struct btree_iter *iter) { BUG_ON(!b->written); __btree_sort(b, iter, 0, b->page_order, true); } void bch_btree_sort_into(struct btree *b, struct btree *new) { uint64_t start_time = local_clock(); struct btree_iter iter; bch_btree_iter_init(b, &iter, NULL); btree_mergesort(b, new->sets->data, &iter, false, true); spin_lock(&b->c->sort_time_lock); bch_time_stats_update(&b->c->sort_time, start_time); spin_unlock(&b->c->sort_time_lock); bkey_copy_key(&new->key, &b->key); new->sets->size = 0; } void bch_btree_sort_lazy(struct btree *b) { if (b->nsets) { unsigned i, j, keys = 0, total; for (i = 0; i <= b->nsets; i++) keys += b->sets[i].data->keys; total = keys; for (j = 0; j < b->nsets; j++) { if (keys * 2 < total || keys < 1000) { bch_btree_sort_partial(b, j); return; } keys -= b->sets[j].data->keys; } /* Must sort if b->nsets == 3 or we'll overflow */ if (b->nsets >= (MAX_BSETS - 1) - b->level) { bch_btree_sort(b); return; } } bset_build_written_tree(b); } /* Sysfs stuff */ struct bset_stats { size_t nodes; size_t sets_written, sets_unwritten; size_t bytes_written, bytes_unwritten; size_t floats, failed; }; static int bch_btree_bset_stats(struct btree *b, struct btree_op *op, struct bset_stats *stats) { struct bkey *k; unsigned i; stats->nodes++; for (i = 0; i <= b->nsets; i++) { struct bset_tree *t = &b->sets[i]; size_t bytes = t->data->keys * sizeof(uint64_t); size_t j; if (bset_written(b, t)) { stats->sets_written++; stats->bytes_written += bytes; stats->floats += t->size - 1; for (j = 1; j < t->size; j++) if (t->tree[j].exponent == 127) stats->failed++; } else { stats->sets_unwritten++; stats->bytes_unwritten += bytes; } } if (b->level) { struct btree_iter iter; for_each_key_filter(b, k, &iter, bch_ptr_bad) { int ret = btree(bset_stats, k, b, op, stats); if (ret) return ret; } } return 0; } int bch_bset_print_stats(struct cache_set *c, char *buf) { struct btree_op op; struct bset_stats t; int ret; bch_btree_op_init_stack(&op); memset(&t, 0, sizeof(struct bset_stats)); ret = btree_root(bset_stats, c, &op, &t); if (ret) return ret; return snprintf(buf, PAGE_SIZE, "btree nodes: %zu\n" "written sets: %zu\n" "unwritten sets: %zu\n" "written key bytes: %zu\n" "unwritten key bytes: %zu\n" "floats: %zu\n" "failed: %zu\n", t.nodes, t.sets_written, t.sets_unwritten, t.bytes_written, t.bytes_unwritten, t.floats, t.failed); }