| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Code for working with individual keys, and sorted sets of keys with in a |
| * btree node |
| * |
| * Copyright 2012 Google, Inc. |
| */ |
| |
| #define pr_fmt(fmt) "bcache: %s() " fmt "\n", __func__ |
| |
| #include "util.h" |
| #include "bset.h" |
| |
| #include <linux/console.h> |
| #include <linux/sched/clock.h> |
| #include <linux/random.h> |
| #include <linux/prefetch.h> |
| |
| #ifdef CONFIG_BCACHE_DEBUG |
| |
| void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned set) |
| { |
| struct bkey *k, *next; |
| |
| for (k = i->start; k < bset_bkey_last(i); k = next) { |
| next = bkey_next(k); |
| |
| printk(KERN_ERR "block %u key %u/%u: ", set, |
| (unsigned) ((u64 *) k - i->d), i->keys); |
| |
| if (b->ops->key_dump) |
| b->ops->key_dump(b, k); |
| else |
| printk("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k)); |
| |
| if (next < bset_bkey_last(i) && |
| bkey_cmp(k, b->ops->is_extents ? |
| &START_KEY(next) : next) > 0) |
| printk(KERN_ERR "Key skipped backwards\n"); |
| } |
| } |
| |
| void bch_dump_bucket(struct btree_keys *b) |
| { |
| unsigned i; |
| |
| console_lock(); |
| for (i = 0; i <= b->nsets; i++) |
| bch_dump_bset(b, b->set[i].data, |
| bset_sector_offset(b, b->set[i].data)); |
| console_unlock(); |
| } |
| |
| int __bch_count_data(struct btree_keys *b) |
| { |
| unsigned ret = 0; |
| struct btree_iter iter; |
| struct bkey *k; |
| |
| if (b->ops->is_extents) |
| for_each_key(b, k, &iter) |
| ret += KEY_SIZE(k); |
| return ret; |
| } |
| |
| void __bch_check_keys(struct btree_keys *b, const char *fmt, ...) |
| { |
| va_list args; |
| struct bkey *k, *p = NULL; |
| struct btree_iter iter; |
| const char *err; |
| |
| for_each_key(b, k, &iter) { |
| if (b->ops->is_extents) { |
| err = "Keys out of order"; |
| if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0) |
| goto bug; |
| |
| if (bch_ptr_invalid(b, k)) |
| continue; |
| |
| err = "Overlapping keys"; |
| if (p && bkey_cmp(p, &START_KEY(k)) > 0) |
| goto bug; |
| } else { |
| if (bch_ptr_bad(b, k)) |
| continue; |
| |
| err = "Duplicate keys"; |
| if (p && !bkey_cmp(p, k)) |
| goto bug; |
| } |
| p = k; |
| } |
| #if 0 |
| err = "Key larger than btree node key"; |
| if (p && bkey_cmp(p, &b->key) > 0) |
| goto bug; |
| #endif |
| return; |
| bug: |
| bch_dump_bucket(b); |
| |
| va_start(args, fmt); |
| vprintk(fmt, args); |
| va_end(args); |
| |
| panic("bch_check_keys error: %s:\n", err); |
| } |
| |
| static void bch_btree_iter_next_check(struct btree_iter *iter) |
| { |
| struct bkey *k = iter->data->k, *next = bkey_next(k); |
| |
| if (next < iter->data->end && |
| bkey_cmp(k, iter->b->ops->is_extents ? |
| &START_KEY(next) : next) > 0) { |
| bch_dump_bucket(iter->b); |
| panic("Key skipped backwards\n"); |
| } |
| } |
| |
| #else |
| |
| static inline void bch_btree_iter_next_check(struct btree_iter *iter) {} |
| |
| #endif |
| |
| /* Keylists */ |
| |
| int __bch_keylist_realloc(struct keylist *l, unsigned u64s) |
| { |
| size_t oldsize = bch_keylist_nkeys(l); |
| size_t newsize = oldsize + u64s; |
| uint64_t *old_keys = l->keys_p == l->inline_keys ? NULL : l->keys_p; |
| uint64_t *new_keys; |
| |
| newsize = roundup_pow_of_two(newsize); |
| |
| if (newsize <= KEYLIST_INLINE || |
| roundup_pow_of_two(oldsize) == newsize) |
| return 0; |
| |
| new_keys = krealloc(old_keys, sizeof(uint64_t) * newsize, GFP_NOIO); |
| |
| if (!new_keys) |
| return -ENOMEM; |
| |
| if (!old_keys) |
| memcpy(new_keys, l->inline_keys, sizeof(uint64_t) * oldsize); |
| |
| l->keys_p = new_keys; |
| l->top_p = new_keys + oldsize; |
| |
| return 0; |
| } |
| |
| struct bkey *bch_keylist_pop(struct keylist *l) |
| { |
| struct bkey *k = l->keys; |
| |
| if (k == l->top) |
| return NULL; |
| |
| while (bkey_next(k) != l->top) |
| k = bkey_next(k); |
| |
| return l->top = k; |
| } |
| |
| void bch_keylist_pop_front(struct keylist *l) |
| { |
| l->top_p -= bkey_u64s(l->keys); |
| |
| memmove(l->keys, |
| bkey_next(l->keys), |
| bch_keylist_bytes(l)); |
| } |
| |
| /* 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; |
| } |
| |
| /* Auxiliary search trees */ |
| |
| /* 32 bits total: */ |
| #define BKEY_MID_BITS 3 |
| #define BKEY_EXPONENT_BITS 7 |
| #define BKEY_MANTISSA_BITS (32 - BKEY_MID_BITS - BKEY_EXPONENT_BITS) |
| #define BKEY_MANTISSA_MASK ((1 << BKEY_MANTISSA_BITS) - 1) |
| |
| struct bkey_float { |
| unsigned exponent:BKEY_EXPONENT_BITS; |
| unsigned m:BKEY_MID_BITS; |
| unsigned mantissa:BKEY_MANTISSA_BITS; |
| } __packed; |
| |
| /* |
| * BSET_CACHELINE was originally intended to match the hardware cacheline size - |
| * it used to be 64, but I realized the lookup code would touch slightly less |
| * memory if it was 128. |
| * |
| * It definites the number of bytes (in struct bset) per struct bkey_float in |
| * the auxiliar search tree - when we're done searching the bset_float tree we |
| * have this many bytes left that we do a linear search over. |
| * |
| * Since (after level 5) every level of the bset_tree is on a new cacheline, |
| * we're touching one fewer cacheline in the bset tree in exchange for one more |
| * cacheline in the linear search - but the linear search might stop before it |
| * gets to the second cacheline. |
| */ |
| |
| #define BSET_CACHELINE 128 |
| |
| /* Space required for the btree node keys */ |
| static inline size_t btree_keys_bytes(struct btree_keys *b) |
| { |
| return PAGE_SIZE << b->page_order; |
| } |
| |
| static inline size_t btree_keys_cachelines(struct btree_keys *b) |
| { |
| return btree_keys_bytes(b) / BSET_CACHELINE; |
| } |
| |
| /* Space required for the auxiliary search trees */ |
| static inline size_t bset_tree_bytes(struct btree_keys *b) |
| { |
| return btree_keys_cachelines(b) * sizeof(struct bkey_float); |
| } |
| |
| /* Space required for the prev pointers */ |
| static inline size_t bset_prev_bytes(struct btree_keys *b) |
| { |
| return btree_keys_cachelines(b) * sizeof(uint8_t); |
| } |
| |
| /* Memory allocation */ |
| |
| void bch_btree_keys_free(struct btree_keys *b) |
| { |
| struct bset_tree *t = b->set; |
| |
| if (bset_prev_bytes(b) < PAGE_SIZE) |
| kfree(t->prev); |
| else |
| free_pages((unsigned long) t->prev, |
| get_order(bset_prev_bytes(b))); |
| |
| if (bset_tree_bytes(b) < PAGE_SIZE) |
| kfree(t->tree); |
| else |
| free_pages((unsigned long) t->tree, |
| get_order(bset_tree_bytes(b))); |
| |
| free_pages((unsigned long) t->data, b->page_order); |
| |
| t->prev = NULL; |
| t->tree = NULL; |
| t->data = NULL; |
| } |
| EXPORT_SYMBOL(bch_btree_keys_free); |
| |
| int bch_btree_keys_alloc(struct btree_keys *b, unsigned page_order, gfp_t gfp) |
| { |
| struct bset_tree *t = b->set; |
| |
| BUG_ON(t->data); |
| |
| b->page_order = page_order; |
| |
| t->data = (void *) __get_free_pages(gfp, b->page_order); |
| if (!t->data) |
| goto err; |
| |
| t->tree = bset_tree_bytes(b) < PAGE_SIZE |
| ? kmalloc(bset_tree_bytes(b), gfp) |
| : (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b))); |
| if (!t->tree) |
| goto err; |
| |
| t->prev = bset_prev_bytes(b) < PAGE_SIZE |
| ? kmalloc(bset_prev_bytes(b), gfp) |
| : (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b))); |
| if (!t->prev) |
| goto err; |
| |
| return 0; |
| err: |
| bch_btree_keys_free(b); |
| return -ENOMEM; |
| } |
| EXPORT_SYMBOL(bch_btree_keys_alloc); |
| |
| void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops, |
| bool *expensive_debug_checks) |
| { |
| unsigned i; |
| |
| b->ops = ops; |
| b->expensive_debug_checks = expensive_debug_checks; |
| b->nsets = 0; |
| b->last_set_unwritten = 0; |
| |
| /* XXX: shouldn't be needed */ |
| for (i = 0; i < MAX_BSETS; i++) |
| b->set[i].size = 0; |
| /* |
| * Second loop starts at 1 because b->keys[0]->data is the memory we |
| * allocated |
| */ |
| for (i = 1; i < MAX_BSETS; i++) |
| b->set[i].data = NULL; |
| } |
| EXPORT_SYMBOL(bch_btree_keys_init); |
| |
| /* 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 arithmetic: |
| * |
| * 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 arithmetic 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 bset_tree *t, |
| unsigned cacheline, |
| struct bkey *k) |
| { |
| return (u64 *) k - (u64 *) cacheline_to_bkey(t, cacheline, 0); |
| } |
| |
| 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) |
| { |
| low >>= shift; |
| low |= (high << 1) << (63U - shift); |
| 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) |
| ? bset_bkey_idx(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_keys *b, struct bset_tree *t) |
| { |
| if (t != b->set) { |
| 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->set + MAX_BSETS) |
| t++->size = 0; |
| } |
| |
| static void bch_bset_build_unwritten_tree(struct btree_keys *b) |
| { |
| struct bset_tree *t = bset_tree_last(b); |
| |
| BUG_ON(b->last_set_unwritten); |
| b->last_set_unwritten = 1; |
| |
| bset_alloc_tree(b, t); |
| |
| if (t->tree != b->set->tree + btree_keys_cachelines(b)) { |
| t->prev[0] = bkey_to_cacheline_offset(t, 0, t->data->start); |
| t->size = 1; |
| } |
| } |
| |
| void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic) |
| { |
| if (i != b->set->data) { |
| b->set[++b->nsets].data = i; |
| i->seq = b->set->data->seq; |
| } else |
| get_random_bytes(&i->seq, sizeof(uint64_t)); |
| |
| i->magic = magic; |
| i->version = 0; |
| i->keys = 0; |
| |
| bch_bset_build_unwritten_tree(b); |
| } |
| EXPORT_SYMBOL(bch_bset_init_next); |
| |
| void bch_bset_build_written_tree(struct btree_keys *b) |
| { |
| struct bset_tree *t = bset_tree_last(b); |
| struct bkey *prev = NULL, *k = t->data->start; |
| unsigned j, cacheline = 1; |
| |
| b->last_set_unwritten = 0; |
| |
| bset_alloc_tree(b, t); |
| |
| t->size = min_t(unsigned, |
| bkey_to_cacheline(t, bset_bkey_last(t->data)), |
| b->set->tree + btree_keys_cachelines(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) |
| prev = k, k = bkey_next(k); |
| |
| t->prev[j] = bkey_u64s(prev); |
| t->tree[j].m = bkey_to_cacheline_offset(t, cacheline++, k); |
| } |
| |
| while (bkey_next(k) != bset_bkey_last(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); |
| } |
| EXPORT_SYMBOL(bch_bset_build_written_tree); |
| |
| /* Insert */ |
| |
| void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k) |
| { |
| struct bset_tree *t; |
| unsigned inorder, j = 1; |
| |
| for (t = b->set; t <= bset_tree_last(b); t++) |
| if (k < bset_bkey_last(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) == bset_bkey_last(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); |
| } |
| EXPORT_SYMBOL(bch_bset_fix_invalidated_key); |
| |
| static void bch_bset_fix_lookup_table(struct btree_keys *b, |
| struct bset_tree *t, |
| struct bkey *k) |
| { |
| 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 |
| */ |
| while (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(t, j, k); |
| } |
| } |
| |
| if (t->size == b->set->tree + btree_keys_cachelines(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 != bset_bkey_last(t->data); |
| k = bkey_next(k)) |
| if (t->size == bkey_to_cacheline(t, k)) { |
| t->prev[t->size] = bkey_to_cacheline_offset(t, t->size, k); |
| t->size++; |
| } |
| } |
| |
| /* |
| * 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_keys *b, struct bkey *l, struct bkey *r) |
| { |
| if (!b->ops->key_merge) |
| return false; |
| |
| /* |
| * Generic header checks |
| * Assumes left and right are in order |
| * Left and right must be exactly aligned |
| */ |
| if (!bch_bkey_equal_header(l, r) || |
| bkey_cmp(l, &START_KEY(r))) |
| return false; |
| |
| return b->ops->key_merge(b, l, r); |
| } |
| EXPORT_SYMBOL(bch_bkey_try_merge); |
| |
| void bch_bset_insert(struct btree_keys *b, struct bkey *where, |
| struct bkey *insert) |
| { |
| struct bset_tree *t = bset_tree_last(b); |
| |
| BUG_ON(!b->last_set_unwritten); |
| BUG_ON(bset_byte_offset(b, t->data) + |
| __set_bytes(t->data, t->data->keys + bkey_u64s(insert)) > |
| PAGE_SIZE << b->page_order); |
| |
| memmove((uint64_t *) where + bkey_u64s(insert), |
| where, |
| (void *) bset_bkey_last(t->data) - (void *) where); |
| |
| t->data->keys += bkey_u64s(insert); |
| bkey_copy(where, insert); |
| bch_bset_fix_lookup_table(b, t, where); |
| } |
| EXPORT_SYMBOL(bch_bset_insert); |
| |
| unsigned bch_btree_insert_key(struct btree_keys *b, struct bkey *k, |
| struct bkey *replace_key) |
| { |
| unsigned status = BTREE_INSERT_STATUS_NO_INSERT; |
| struct bset *i = bset_tree_last(b)->data; |
| struct bkey *m, *prev = NULL; |
| struct btree_iter iter; |
| |
| BUG_ON(b->ops->is_extents && !KEY_SIZE(k)); |
| |
| m = bch_btree_iter_init(b, &iter, b->ops->is_extents |
| ? PRECEDING_KEY(&START_KEY(k)) |
| : PRECEDING_KEY(k)); |
| |
| if (b->ops->insert_fixup(b, k, &iter, replace_key)) |
| return status; |
| |
| status = BTREE_INSERT_STATUS_INSERT; |
| |
| while (m != bset_bkey_last(i) && |
| bkey_cmp(k, b->ops->is_extents ? &START_KEY(m) : m) > 0) |
| prev = m, m = bkey_next(m); |
| |
| /* prev is in the tree, if we merge we're done */ |
| status = BTREE_INSERT_STATUS_BACK_MERGE; |
| if (prev && |
| bch_bkey_try_merge(b, prev, k)) |
| goto merged; |
| #if 0 |
| status = BTREE_INSERT_STATUS_OVERWROTE; |
| if (m != bset_bkey_last(i) && |
| KEY_PTRS(m) == KEY_PTRS(k) && !KEY_SIZE(m)) |
| goto copy; |
| #endif |
| status = BTREE_INSERT_STATUS_FRONT_MERGE; |
| if (m != bset_bkey_last(i) && |
| bch_bkey_try_merge(b, k, m)) |
| goto copy; |
| |
| bch_bset_insert(b, m, k); |
| copy: bkey_copy(m, k); |
| merged: |
| return status; |
| } |
| EXPORT_SYMBOL(bch_btree_insert_key); |
| |
| /* Lookup */ |
| |
| struct bset_search_iter { |
| struct bkey *l, *r; |
| }; |
| |
| static struct bset_search_iter bset_search_write_set(struct bset_tree *t, |
| const struct bkey *search) |
| { |
| unsigned li = 0, ri = t->size; |
| |
| 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) : bset_bkey_last(t->data) |
| }; |
| } |
| |
| static struct bset_search_iter bset_search_tree(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 = bset_bkey_last(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_keys *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 = bset_bkey_last(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 bset_bkey_last(t->data); |
| |
| if (unlikely(bkey_cmp(search, t->data->start) < 0)) |
| return t->data->start; |
| |
| i = bset_search_tree(t, search); |
| } else { |
| BUG_ON(!b->nsets && |
| t->size < bkey_to_cacheline(t, bset_bkey_last(t->data))); |
| |
| i = bset_search_write_set(t, search); |
| } |
| |
| if (btree_keys_expensive_checks(b)) { |
| 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 != bset_bkey_last(t->data) && |
| bkey_cmp(i.r, search) <= 0); |
| } |
| |
| while (likely(i.l != i.r) && |
| bkey_cmp(i.l, search) <= 0) |
| i.l = bkey_next(i.l); |
| |
| return i.l; |
| } |
| EXPORT_SYMBOL(__bch_bset_search); |
| |
| /* Btree iterator */ |
| |
| typedef bool (btree_iter_cmp_fn)(struct btree_iter_set, |
| struct btree_iter_set); |
| |
| static inline bool btree_iter_cmp(struct btree_iter_set l, |
| struct btree_iter_set r) |
| { |
| return bkey_cmp(l.k, r.k) > 0; |
| } |
| |
| 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)); |
| } |
| |
| static struct bkey *__bch_btree_iter_init(struct btree_keys *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; |
| |
| #ifdef CONFIG_BCACHE_DEBUG |
| iter->b = b; |
| #endif |
| |
| for (; start <= bset_tree_last(b); start++) { |
| ret = bch_bset_search(b, start, search); |
| bch_btree_iter_push(iter, ret, bset_bkey_last(start->data)); |
| } |
| |
| return ret; |
| } |
| |
| struct bkey *bch_btree_iter_init(struct btree_keys *b, |
| struct btree_iter *iter, |
| struct bkey *search) |
| { |
| return __bch_btree_iter_init(b, iter, search, b->set); |
| } |
| EXPORT_SYMBOL(bch_btree_iter_init); |
| |
| static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter, |
| btree_iter_cmp_fn *cmp) |
| { |
| struct btree_iter_set b __maybe_unused; |
| struct bkey *ret = NULL; |
| |
| if (!btree_iter_end(iter)) { |
| bch_btree_iter_next_check(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, b, cmp); |
| else |
| heap_sift(iter, 0, cmp); |
| } |
| |
| return ret; |
| } |
| |
| struct bkey *bch_btree_iter_next(struct btree_iter *iter) |
| { |
| return __bch_btree_iter_next(iter, btree_iter_cmp); |
| |
| } |
| EXPORT_SYMBOL(bch_btree_iter_next); |
| |
| struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter, |
| struct btree_keys *b, ptr_filter_fn fn) |
| { |
| struct bkey *ret; |
| |
| do { |
| ret = bch_btree_iter_next(iter); |
| } while (ret && fn(b, ret)); |
| |
| return ret; |
| } |
| |
| /* Mergesort */ |
| |
| void bch_bset_sort_state_free(struct bset_sort_state *state) |
| { |
| if (state->pool) |
| mempool_destroy(state->pool); |
| } |
| |
| int bch_bset_sort_state_init(struct bset_sort_state *state, unsigned page_order) |
| { |
| spin_lock_init(&state->time.lock); |
| |
| state->page_order = page_order; |
| state->crit_factor = int_sqrt(1 << page_order); |
| |
| state->pool = mempool_create_page_pool(1, page_order); |
| if (!state->pool) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(bch_bset_sort_state_init); |
| |
| static void btree_mergesort(struct btree_keys *b, struct bset *out, |
| struct btree_iter *iter, |
| bool fixup, bool remove_stale) |
| { |
| int i; |
| struct bkey *k, *last = NULL; |
| BKEY_PADDED(k) tmp; |
| bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale |
| ? bch_ptr_bad |
| : bch_ptr_invalid; |
| |
| /* Heapify the iterator, using our comparison function */ |
| for (i = iter->used / 2 - 1; i >= 0; --i) |
| heap_sift(iter, i, b->ops->sort_cmp); |
| |
| while (!btree_iter_end(iter)) { |
| if (b->ops->sort_fixup && fixup) |
| k = b->ops->sort_fixup(iter, &tmp.k); |
| else |
| k = NULL; |
| |
| if (!k) |
| k = __bch_btree_iter_next(iter, b->ops->sort_cmp); |
| |
| if (bad(b, k)) |
| continue; |
| |
| if (!last) { |
| last = out->start; |
| bkey_copy(last, k); |
| } else if (!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); |
| } |
| |
| static void __btree_sort(struct btree_keys *b, struct btree_iter *iter, |
| unsigned start, unsigned order, bool fixup, |
| struct bset_sort_state *state) |
| { |
| uint64_t start_time; |
| bool used_mempool = false; |
| struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOWAIT, |
| order); |
| if (!out) { |
| struct page *outp; |
| |
| BUG_ON(order > state->page_order); |
| |
| outp = mempool_alloc(state->pool, GFP_NOIO); |
| out = page_address(outp); |
| used_mempool = true; |
| order = state->page_order; |
| } |
| |
| start_time = local_clock(); |
| |
| btree_mergesort(b, out, iter, fixup, false); |
| b->nsets = start; |
| |
| 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 = b->set->data->magic; |
| out->seq = b->set->data->seq; |
| out->version = b->set->data->version; |
| swap(out, b->set->data); |
| } else { |
| b->set[start].data->keys = out->keys; |
| memcpy(b->set[start].data->start, out->start, |
| (void *) bset_bkey_last(out) - (void *) out->start); |
| } |
| |
| if (used_mempool) |
| mempool_free(virt_to_page(out), state->pool); |
| else |
| free_pages((unsigned long) out, order); |
| |
| bch_bset_build_written_tree(b); |
| |
| if (!start) |
| bch_time_stats_update(&state->time, start_time); |
| } |
| |
| void bch_btree_sort_partial(struct btree_keys *b, unsigned start, |
| struct bset_sort_state *state) |
| { |
| size_t order = b->page_order, keys = 0; |
| struct btree_iter iter; |
| int oldsize = bch_count_data(b); |
| |
| __bch_btree_iter_init(b, &iter, NULL, &b->set[start]); |
| |
| if (start) { |
| unsigned i; |
| |
| for (i = start; i <= b->nsets; i++) |
| keys += b->set[i].data->keys; |
| |
| order = get_order(__set_bytes(b->set->data, keys)); |
| } |
| |
| __btree_sort(b, &iter, start, order, false, state); |
| |
| EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize); |
| } |
| EXPORT_SYMBOL(bch_btree_sort_partial); |
| |
| void bch_btree_sort_and_fix_extents(struct btree_keys *b, |
| struct btree_iter *iter, |
| struct bset_sort_state *state) |
| { |
| __btree_sort(b, iter, 0, b->page_order, true, state); |
| } |
| |
| void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new, |
| struct bset_sort_state *state) |
| { |
| uint64_t start_time = local_clock(); |
| |
| struct btree_iter iter; |
| bch_btree_iter_init(b, &iter, NULL); |
| |
| btree_mergesort(b, new->set->data, &iter, false, true); |
| |
| bch_time_stats_update(&state->time, start_time); |
| |
| new->set->size = 0; // XXX: why? |
| } |
| |
| #define SORT_CRIT (4096 / sizeof(uint64_t)) |
| |
| void bch_btree_sort_lazy(struct btree_keys *b, struct bset_sort_state *state) |
| { |
| unsigned crit = SORT_CRIT; |
| int i; |
| |
| /* Don't sort if nothing to do */ |
| if (!b->nsets) |
| goto out; |
| |
| for (i = b->nsets - 1; i >= 0; --i) { |
| crit *= state->crit_factor; |
| |
| if (b->set[i].data->keys < crit) { |
| bch_btree_sort_partial(b, i, state); |
| return; |
| } |
| } |
| |
| /* Sort if we'd overflow */ |
| if (b->nsets + 1 == MAX_BSETS) { |
| bch_btree_sort(b, state); |
| return; |
| } |
| |
| out: |
| bch_bset_build_written_tree(b); |
| } |
| EXPORT_SYMBOL(bch_btree_sort_lazy); |
| |
| void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats) |
| { |
| unsigned i; |
| |
| for (i = 0; i <= b->nsets; i++) { |
| struct bset_tree *t = &b->set[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; |
| } |
| } |
| } |