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-rw-r--r--libbcache/bset.c1846
1 files changed, 0 insertions, 1846 deletions
diff --git a/libbcache/bset.c b/libbcache/bset.c
deleted file mode 100644
index a88d8017..00000000
--- a/libbcache/bset.c
+++ /dev/null
@@ -1,1846 +0,0 @@
-/*
- * 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 "eytzinger.h"
-#include "util.h"
-#include "bset.h"
-
-#include <asm/unaligned.h>
-#include <linux/dynamic_fault.h>
-#include <linux/console.h>
-#include <linux/random.h>
-#include <linux/prefetch.h>
-
-/* hack.. */
-#include "alloc_types.h"
-#include <trace/events/bcache.h>
-
-struct bset_tree *bch_bkey_to_bset(struct btree *b, struct bkey_packed *k)
-{
- struct bset_tree *t;
-
- for_each_bset(b, t)
- if (k >= btree_bkey_first(b, t) &&
- k < btree_bkey_last(b, t))
- return t;
-
- BUG();
-}
-
-/*
- * There are never duplicate live keys in the btree - but including keys that
- * have been flagged as deleted (and will be cleaned up later) we _will_ see
- * duplicates.
- *
- * Thus the sort order is: usual key comparison first, but for keys that compare
- * equal the deleted key(s) come first, and the (at most one) live version comes
- * last.
- *
- * The main reason for this is insertion: to handle overwrites, we first iterate
- * over keys that compare equal to our insert key, and then insert immediately
- * prior to the first key greater than the key we're inserting - our insert
- * position will be after all keys that compare equal to our insert key, which
- * by the time we actually do the insert will all be deleted.
- */
-
-void bch_dump_bset(struct btree *b, struct bset *i, unsigned set)
-{
- struct bkey_packed *_k, *_n;
- struct bkey k, n;
- char buf[120];
-
- if (!i->u64s)
- return;
-
- for (_k = i->start, k = bkey_unpack_key(b, _k);
- _k < vstruct_last(i);
- _k = _n, k = n) {
- _n = bkey_next(_k);
-
- bch_bkey_to_text(buf, sizeof(buf), &k);
- printk(KERN_ERR "block %u key %zi/%u: %s\n", set,
- _k->_data - i->_data, i->u64s, buf);
-
- if (_n == vstruct_last(i))
- continue;
-
- n = bkey_unpack_key(b, _n);
-
- if (bkey_cmp(bkey_start_pos(&n), k.p) < 0) {
- printk(KERN_ERR "Key skipped backwards\n");
- continue;
- }
-
- /*
- * Weird check for duplicate non extent keys: extents are
- * deleted iff they have 0 size, so if it has zero size and it's
- * not deleted these aren't extents:
- */
- if (((!k.size && !bkey_deleted(&k)) ||
- (!n.size && !bkey_deleted(&n))) &&
- !bkey_deleted(&k) &&
- !bkey_cmp(n.p, k.p))
- printk(KERN_ERR "Duplicate keys\n");
- }
-}
-
-void bch_dump_btree_node(struct btree *b)
-{
- struct bset_tree *t;
-
- console_lock();
- for_each_bset(b, t)
- bch_dump_bset(b, bset(b, t), t - b->set);
- console_unlock();
-}
-
-void bch_dump_btree_node_iter(struct btree *b,
- struct btree_node_iter *iter)
-{
- struct btree_node_iter_set *set;
-
- printk(KERN_ERR "btree node iter with %u sets:\n", b->nsets);
-
- btree_node_iter_for_each(iter, set) {
- struct bkey_packed *k = __btree_node_offset_to_key(b, set->k);
- struct bset_tree *t = bch_bkey_to_bset(b, k);
- struct bkey uk = bkey_unpack_key(b, k);
- char buf[100];
-
- bch_bkey_to_text(buf, sizeof(buf), &uk);
- printk(KERN_ERR "set %zu key %zi/%u: %s\n", t - b->set,
- k->_data - bset(b, t)->_data, bset(b, t)->u64s, buf);
- }
-}
-
-#ifdef CONFIG_BCACHE_DEBUG
-
-static bool keys_out_of_order(struct btree *b,
- const struct bkey_packed *prev,
- const struct bkey_packed *next,
- bool is_extents)
-{
- struct bkey nextu = bkey_unpack_key(b, next);
-
- return bkey_cmp_left_packed_byval(b, prev, bkey_start_pos(&nextu)) > 0 ||
- ((is_extents
- ? !bkey_deleted(next)
- : !bkey_deleted(prev)) &&
- !bkey_cmp_packed(b, prev, next));
-}
-
-void __bch_verify_btree_nr_keys(struct btree *b)
-{
- struct bset_tree *t;
- struct bkey_packed *k;
- struct btree_nr_keys nr = { 0 };
-
- for_each_bset(b, t)
- for (k = btree_bkey_first(b, t);
- k != btree_bkey_last(b, t);
- k = bkey_next(k))
- if (!bkey_whiteout(k))
- btree_keys_account_key_add(&nr, t - b->set, k);
-
- BUG_ON(memcmp(&nr, &b->nr, sizeof(nr)));
-}
-
-static void bch_btree_node_iter_next_check(struct btree_node_iter *iter,
- struct btree *b,
- struct bkey_packed *k)
-{
- const struct bkey_packed *n = bch_btree_node_iter_peek_all(iter, b);
-
- bkey_unpack_key(b, k);
-
- if (n &&
- keys_out_of_order(b, k, n, iter->is_extents)) {
- struct bkey ku = bkey_unpack_key(b, k);
- struct bkey nu = bkey_unpack_key(b, n);
- char buf1[80], buf2[80];
-
- bch_dump_btree_node(b);
- bch_bkey_to_text(buf1, sizeof(buf1), &ku);
- bch_bkey_to_text(buf2, sizeof(buf2), &nu);
- panic("out of order/overlapping:\n%s\n%s\n", buf1, buf2);
- }
-}
-
-void bch_btree_node_iter_verify(struct btree_node_iter *iter,
- struct btree *b)
-{
- struct btree_node_iter_set *set;
- struct bset_tree *t;
- struct bkey_packed *k, *first;
-
- BUG_ON(iter->used > MAX_BSETS);
-
- if (!iter->used)
- return;
-
- btree_node_iter_for_each(iter, set) {
- k = __btree_node_offset_to_key(b, set->k);
- t = bch_bkey_to_bset(b, k);
-
- BUG_ON(__btree_node_offset_to_key(b, set->end) !=
- btree_bkey_last(b, t));
-
- BUG_ON(set + 1 < iter->data + iter->used &&
- btree_node_iter_cmp(iter, b, set[0], set[1]) > 0);
- }
-
- first = __btree_node_offset_to_key(b, iter->data[0].k);
-
- for_each_bset(b, t)
- if (bch_btree_node_iter_bset_pos(iter, b, t) ==
- btree_bkey_last(b, t) &&
- (k = bkey_prev_all(b, t, btree_bkey_last(b, t))))
- BUG_ON(__btree_node_iter_cmp(iter->is_extents, b,
- k, first) > 0);
-}
-
-void bch_verify_key_order(struct btree *b,
- struct btree_node_iter *iter,
- struct bkey_packed *where)
-{
- struct bset_tree *t = bch_bkey_to_bset(b, where);
- struct bkey_packed *k, *prev;
- struct bkey uk, uw = bkey_unpack_key(b, where);
-
- k = bkey_prev_all(b, t, where);
- if (k &&
- keys_out_of_order(b, k, where, iter->is_extents)) {
- char buf1[100], buf2[100];
-
- bch_dump_btree_node(b);
- uk = bkey_unpack_key(b, k);
- bch_bkey_to_text(buf1, sizeof(buf1), &uk);
- bch_bkey_to_text(buf2, sizeof(buf2), &uw);
- panic("out of order with prev:\n%s\n%s\n",
- buf1, buf2);
- }
-
- k = bkey_next(where);
- BUG_ON(k != btree_bkey_last(b, t) &&
- keys_out_of_order(b, where, k, iter->is_extents));
-
- for_each_bset(b, t) {
- if (where >= btree_bkey_first(b, t) ||
- where < btree_bkey_last(b, t))
- continue;
-
- k = bch_btree_node_iter_bset_pos(iter, b, t);
-
- if (k == btree_bkey_last(b, t))
- k = bkey_prev_all(b, t, k);
-
- while (bkey_cmp_left_packed_byval(b, k, bkey_start_pos(&uw)) > 0 &&
- (prev = bkey_prev_all(b, t, k)))
- k = prev;
-
- for (;
- k != btree_bkey_last(b, t);
- k = bkey_next(k)) {
- uk = bkey_unpack_key(b, k);
-
- if (iter->is_extents) {
- BUG_ON(!(bkey_cmp(uw.p, bkey_start_pos(&uk)) <= 0 ||
- bkey_cmp(uk.p, bkey_start_pos(&uw)) <= 0));
- } else {
- BUG_ON(!bkey_cmp(uw.p, uk.p) &&
- !bkey_deleted(&uk));
- }
-
- if (bkey_cmp(uw.p, bkey_start_pos(&uk)) <= 0)
- break;
- }
- }
-}
-
-#else
-
-static void bch_btree_node_iter_next_check(struct btree_node_iter *iter,
- struct btree *b,
- struct bkey_packed *k) {}
-
-#endif
-
-/* Auxiliary search trees */
-
-#define BFLOAT_FAILED_UNPACKED (U8_MAX - 0)
-#define BFLOAT_FAILED_PREV (U8_MAX - 1)
-#define BFLOAT_FAILED_OVERFLOW (U8_MAX - 2)
-#define BFLOAT_FAILED (U8_MAX - 2)
-
-#define KEY_WORDS BITS_TO_LONGS(1 << BKEY_EXPONENT_BITS)
-
-struct bkey_float {
- u8 exponent;
- u8 key_offset;
- union {
- u32 mantissa32;
- struct {
- u16 mantissa16;
- u16 _pad;
- };
- };
-} __packed;
-
-#define BFLOAT_32BIT_NR 32U
-
-static unsigned bkey_float_byte_offset(unsigned idx)
-{
- int d = (idx - BFLOAT_32BIT_NR) << 1;
-
- d &= ~(d >> 31);
-
- return idx * 6 - d;
-}
-
-struct ro_aux_tree {
- struct bkey_float _d[0];
-};
-
-struct rw_aux_tree {
- u16 offset;
- struct bpos k;
-};
-
-/*
- * 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 *b)
-{
- return PAGE_SIZE << b->page_order;
-}
-
-static inline size_t btree_keys_cachelines(struct btree *b)
-{
- return btree_keys_bytes(b) / BSET_CACHELINE;
-}
-
-static inline size_t btree_aux_data_bytes(struct btree *b)
-{
- return btree_keys_cachelines(b) * 8;
-}
-
-static inline size_t btree_aux_data_u64s(struct btree *b)
-{
- return btree_aux_data_bytes(b) / sizeof(u64);
-}
-
-static unsigned bset_aux_tree_buf_end(const struct bset_tree *t)
-{
- BUG_ON(t->aux_data_offset == U16_MAX);
-
- switch (bset_aux_tree_type(t)) {
- case BSET_NO_AUX_TREE:
- return t->aux_data_offset;
- case BSET_RO_AUX_TREE:
- return t->aux_data_offset +
- DIV_ROUND_UP(bkey_float_byte_offset(t->size) +
- sizeof(u8) * t->size, 8);
- case BSET_RW_AUX_TREE:
- return t->aux_data_offset +
- DIV_ROUND_UP(sizeof(struct rw_aux_tree) * t->size, 8);
- default:
- BUG();
- }
-}
-
-static unsigned bset_aux_tree_buf_start(const struct btree *b,
- const struct bset_tree *t)
-{
- return t == b->set
- ? DIV_ROUND_UP(b->unpack_fn_len, 8)
- : bset_aux_tree_buf_end(t - 1);
-}
-
-static void *__aux_tree_base(const struct btree *b,
- const struct bset_tree *t)
-{
- return b->aux_data + t->aux_data_offset * 8;
-}
-
-static struct ro_aux_tree *ro_aux_tree_base(const struct btree *b,
- const struct bset_tree *t)
-{
- EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
-
- return __aux_tree_base(b, t);
-}
-
-static u8 *ro_aux_tree_prev(const struct btree *b,
- const struct bset_tree *t)
-{
- EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
-
- return __aux_tree_base(b, t) + bkey_float_byte_offset(t->size);
-}
-
-static struct bkey_float *bkey_float_get(struct ro_aux_tree *b,
- unsigned idx)
-{
- return (void *) b + bkey_float_byte_offset(idx);
-}
-
-static struct bkey_float *bkey_float(const struct btree *b,
- const struct bset_tree *t,
- unsigned idx)
-{
- return bkey_float_get(ro_aux_tree_base(b, t), idx);
-}
-
-static void bset_aux_tree_verify(struct btree *b)
-{
-#ifdef CONFIG_BCACHE_DEBUG
- struct bset_tree *t;
-
- for_each_bset(b, t) {
- if (t->aux_data_offset == U16_MAX)
- continue;
-
- BUG_ON(t != b->set &&
- t[-1].aux_data_offset == U16_MAX);
-
- BUG_ON(t->aux_data_offset < bset_aux_tree_buf_start(b, t));
- BUG_ON(t->aux_data_offset > btree_aux_data_u64s(b));
- BUG_ON(bset_aux_tree_buf_end(t) > btree_aux_data_u64s(b));
- }
-#endif
-}
-
-/* Memory allocation */
-
-void bch_btree_keys_free(struct btree *b)
-{
- vfree(b->aux_data);
- b->aux_data = NULL;
-}
-
-int bch_btree_keys_alloc(struct btree *b, unsigned page_order, gfp_t gfp)
-{
- b->page_order = page_order;
- b->aux_data = __vmalloc(btree_aux_data_bytes(b), gfp,
- PAGE_KERNEL_EXEC);
- if (!b->aux_data)
- return -ENOMEM;
-
- return 0;
-}
-
-void bch_btree_keys_init(struct btree *b, bool *expensive_debug_checks)
-{
- unsigned i;
-
- b->nsets = 0;
- memset(&b->nr, 0, sizeof(b->nr));
-#ifdef CONFIG_BCACHE_DEBUG
- b->expensive_debug_checks = expensive_debug_checks;
-#endif
- for (i = 0; i < MAX_BSETS; i++)
- b->set[i].data_offset = U16_MAX;
-
- bch_bset_set_no_aux_tree(b, b->set);
-}
-
-/* Binary tree stuff for auxiliary search trees */
-
-/*
- * 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; eytzinger_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 inline void *bset_cacheline(const struct btree *b,
- const struct bset_tree *t,
- unsigned cacheline)
-{
- return (void *) round_down((unsigned long) btree_bkey_first(b, t),
- L1_CACHE_BYTES) +
- cacheline * BSET_CACHELINE;
-}
-
-static struct bkey_packed *cacheline_to_bkey(const struct btree *b,
- const struct bset_tree *t,
- unsigned cacheline,
- unsigned offset)
-{
- return bset_cacheline(b, t, cacheline) + offset * 8;
-}
-
-static unsigned bkey_to_cacheline(const struct btree *b,
- const struct bset_tree *t,
- const struct bkey_packed *k)
-{
- return ((void *) k - bset_cacheline(b, t, 0)) / BSET_CACHELINE;
-}
-
-static ssize_t __bkey_to_cacheline_offset(const struct btree *b,
- const struct bset_tree *t,
- unsigned cacheline,
- const struct bkey_packed *k)
-{
- return (u64 *) k - (u64 *) bset_cacheline(b, t, cacheline);
-}
-
-static unsigned bkey_to_cacheline_offset(const struct btree *b,
- const struct bset_tree *t,
- unsigned cacheline,
- const struct bkey_packed *k)
-{
- size_t m = __bkey_to_cacheline_offset(b, t, cacheline, k);
-
- EBUG_ON(m > U8_MAX);
- return m;
-}
-
-static inline struct bkey_packed *tree_to_bkey(const struct btree *b,
- const struct bset_tree *t,
- unsigned j)
-{
- return cacheline_to_bkey(b, t,
- __eytzinger_to_inorder(j, t->size, t->extra),
- bkey_float(b, t, j)->key_offset);
-}
-
-static struct bkey_packed *tree_to_prev_bkey(const struct btree *b,
- const struct bset_tree *t,
- unsigned j)
-{
- unsigned prev_u64s = ro_aux_tree_prev(b, t)[j];
-
- return (void *) (tree_to_bkey(b, t, j)->_data - prev_u64s);
-}
-
-static struct rw_aux_tree *rw_aux_tree(const struct btree *b,
- const struct bset_tree *t)
-{
- EBUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);
-
- return __aux_tree_base(b, t);
-}
-
-/*
- * 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_packed *rw_aux_to_bkey(const struct btree *b,
- struct bset_tree *t,
- unsigned j)
-{
- return __btree_node_offset_to_key(b, rw_aux_tree(b, t)[j].offset);
-}
-
-static void rw_aux_tree_set(const struct btree *b, struct bset_tree *t,
- unsigned j, struct bkey_packed *k)
-{
- BUG_ON(k >= btree_bkey_last(b, t));
-
- rw_aux_tree(b, t)[j] = (struct rw_aux_tree) {
- .offset = __btree_node_key_to_offset(b, k),
- .k = bkey_unpack_pos(b, k),
- };
-}
-
-static void bch_bset_verify_rw_aux_tree(struct btree *b,
- struct bset_tree *t)
-{
- struct bkey_packed *k = btree_bkey_first(b, t);
- unsigned j = 0;
-
- if (!btree_keys_expensive_checks(b))
- return;
-
- BUG_ON(bset_has_ro_aux_tree(t));
-
- if (!bset_has_rw_aux_tree(t))
- return;
-
- BUG_ON(t->size < 1);
- BUG_ON(rw_aux_to_bkey(b, t, j) != k);
-
- goto start;
- while (1) {
- if (rw_aux_to_bkey(b, t, j) == k) {
- BUG_ON(bkey_cmp(rw_aux_tree(b, t)[j].k,
- bkey_unpack_pos(b, k)));
-start:
- if (++j == t->size)
- break;
-
- BUG_ON(rw_aux_tree(b, t)[j].offset <=
- rw_aux_tree(b, t)[j - 1].offset);
- }
-
- k = bkey_next(k);
- BUG_ON(k >= btree_bkey_last(b, t));
- }
-}
-
-/* returns idx of first entry >= offset: */
-static unsigned rw_aux_tree_bsearch(struct btree *b,
- struct bset_tree *t,
- unsigned offset)
-{
- unsigned l = 0, r = t->size;
-
- BUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);
-
- while (l < r) {
- unsigned m = (l + r) >> 1;
-
- if (rw_aux_tree(b, t)[m].offset < offset)
- l = m + 1;
- else
- r = m;
- }
-
- BUG_ON(l < t->size &&
- rw_aux_tree(b, t)[l].offset < offset);
- BUG_ON(l &&
- rw_aux_tree(b, t)[l - 1].offset >= offset);
-
- BUG_ON(l > r);
- BUG_ON(l > t->size);
-
- return l;
-}
-
-static inline unsigned bfloat_mantissa(const struct bkey_float *f,
- unsigned idx)
-{
- return idx < BFLOAT_32BIT_NR ? f->mantissa32 : f->mantissa16;
-}
-
-static inline void bfloat_mantissa_set(struct bkey_float *f,
- unsigned idx, unsigned mantissa)
-{
- if (idx < BFLOAT_32BIT_NR)
- f->mantissa32 = mantissa;
- else
- f->mantissa16 = mantissa;
-}
-
-static inline unsigned bkey_mantissa(const struct bkey_packed *k,
- const struct bkey_float *f,
- unsigned idx)
-{
- u64 v;
-
- EBUG_ON(!bkey_packed(k));
-
- v = get_unaligned((u64 *) (((u8 *) k->_data) + (f->exponent >> 3)));
-
- /*
- * In little endian, we're shifting off low bits (and then the bits we
- * want are at the low end), in big endian we're shifting off high bits
- * (and then the bits we want are at the high end, so we shift them
- * back down):
- */
-#ifdef __LITTLE_ENDIAN
- v >>= f->exponent & 7;
-#else
- v >>= 64 - (f->exponent & 7) - (idx < BFLOAT_32BIT_NR ? 32 : 16);
-#endif
- return idx < BFLOAT_32BIT_NR ? (u32) v : (u16) v;
-}
-
-static void make_bfloat(struct btree *b, struct bset_tree *t,
- unsigned j,
- struct bkey_packed *min_key,
- struct bkey_packed *max_key)
-{
- struct bkey_float *f = bkey_float(b, t, j);
- struct bkey_packed *m = tree_to_bkey(b, t, j);
- struct bkey_packed *p = tree_to_prev_bkey(b, t, j);
- struct bkey_packed *l, *r;
- unsigned bits = j < BFLOAT_32BIT_NR ? 32 : 16;
- unsigned mantissa;
- int shift, exponent;
-
- EBUG_ON(bkey_next(p) != m);
-
- if (is_power_of_2(j)) {
- l = min_key;
-
- if (!l->u64s) {
- if (!bkey_pack_pos(l, b->data->min_key, b)) {
- struct bkey_i tmp;
-
- bkey_init(&tmp.k);
- tmp.k.p = b->data->min_key;
- bkey_copy(l, &tmp);
- }
- }
- } else {
- l = tree_to_prev_bkey(b, t, j >> ffs(j));
-
- EBUG_ON(m < l);
- }
-
- if (is_power_of_2(j + 1)) {
- r = max_key;
-
- if (!r->u64s) {
- if (!bkey_pack_pos(r, t->max_key, b)) {
- struct bkey_i tmp;
-
- bkey_init(&tmp.k);
- tmp.k.p = t->max_key;
- bkey_copy(r, &tmp);
- }
- }
- } else {
- r = tree_to_bkey(b, t, j >> (ffz(j) + 1));
-
- EBUG_ON(m > r);
- }
-
- /*
- * for failed bfloats, the lookup code falls back to comparing against
- * the original key.
- */
-
- if (!bkey_packed(l) || !bkey_packed(r) ||
- !bkey_packed(p) || !bkey_packed(m)) {
- f->exponent = BFLOAT_FAILED_UNPACKED;
- return;
- }
-
- /*
- * The greatest differing bit of l and r is the first bit we must
- * include in the bfloat mantissa we're creating in order to do
- * comparisons - that bit always becomes the high bit of
- * bfloat->mantissa, and thus the exponent we're calculating here is
- * the position of what will become the low bit in bfloat->mantissa:
- *
- * Note that this may be negative - we may be running off the low end
- * of the key: we handle this later:
- */
- exponent = (int) bkey_greatest_differing_bit(b, l, r) - (bits - 1);
-
- /*
- * Then we calculate the actual shift value, from the start of the key
- * (k->_data), to get the key bits starting at exponent:
- */
-#ifdef __LITTLE_ENDIAN
- shift = (int) (b->format.key_u64s * 64 - b->nr_key_bits) + exponent;
-
- EBUG_ON(shift + bits > b->format.key_u64s * 64);
-#else
- shift = high_bit_offset +
- b->nr_key_bits -
- exponent -
- bits;
-
- EBUG_ON(shift < KEY_PACKED_BITS_START);
-#endif
- EBUG_ON(shift < 0 || shift >= BFLOAT_FAILED);
-
- f->exponent = shift;
- mantissa = bkey_mantissa(m, f, j);
-
- /*
- * If we've got garbage bits, set them to all 1s - it's legal for the
- * bfloat to compare larger than the original key, but not smaller:
- */
- if (exponent < 0)
- mantissa |= ~(~0U << -exponent);
-
- bfloat_mantissa_set(f, j, mantissa);
-
- /*
- * The bfloat must be able to tell its key apart from the previous key -
- * if its key and the previous key don't differ in the required bits,
- * flag as failed - unless the keys are actually equal, in which case
- * we aren't required to return a specific one:
- */
- if (exponent > 0 &&
- bfloat_mantissa(f, j) == bkey_mantissa(p, f, j) &&
- bkey_cmp_packed(b, p, m)) {
- f->exponent = BFLOAT_FAILED_PREV;
- return;
- }
-
- /*
- * f->mantissa must compare >= the original key - for transitivity with
- * the comparison in bset_search_tree. If we're dropping set bits,
- * increment it:
- */
- if (exponent > (int) bkey_ffs(b, m)) {
- if (j < BFLOAT_32BIT_NR
- ? f->mantissa32 == U32_MAX
- : f->mantissa16 == U16_MAX)
- f->exponent = BFLOAT_FAILED_OVERFLOW;
-
- if (j < BFLOAT_32BIT_NR)
- f->mantissa32++;
- else
- f->mantissa16++;
- }
-}
-
-/* bytes remaining - only valid for last bset: */
-static unsigned __bset_tree_capacity(struct btree *b, struct bset_tree *t)
-{
- bset_aux_tree_verify(b);
-
- return btree_aux_data_bytes(b) - t->aux_data_offset * sizeof(u64);
-}
-
-static unsigned bset_ro_tree_capacity(struct btree *b, struct bset_tree *t)
-{
- unsigned bytes = __bset_tree_capacity(b, t);
-
- if (bytes < 7 * BFLOAT_32BIT_NR)
- return bytes / 7;
-
- bytes -= 7 * BFLOAT_32BIT_NR;
-
- return BFLOAT_32BIT_NR + bytes / 5;
-}
-
-static unsigned bset_rw_tree_capacity(struct btree *b, struct bset_tree *t)
-{
- return __bset_tree_capacity(b, t) / sizeof(struct rw_aux_tree);
-}
-
-static void __build_rw_aux_tree(struct btree *b, struct bset_tree *t)
-{
- struct bkey_packed *k;
-
- t->size = 1;
- t->extra = BSET_RW_AUX_TREE_VAL;
- rw_aux_tree(b, t)[0].offset =
- __btree_node_key_to_offset(b, btree_bkey_first(b, t));
-
- for (k = btree_bkey_first(b, t);
- k != btree_bkey_last(b, t);
- k = bkey_next(k)) {
- if (t->size == bset_rw_tree_capacity(b, t))
- break;
-
- if ((void *) k - (void *) rw_aux_to_bkey(b, t, t->size - 1) >
- L1_CACHE_BYTES)
- rw_aux_tree_set(b, t, t->size++, k);
- }
-}
-
-static void __build_ro_aux_tree(struct btree *b, struct bset_tree *t)
-{
- struct bkey_packed *prev = NULL, *k = btree_bkey_first(b, t);
- struct bkey_packed min_key, max_key;
- unsigned j, cacheline = 1;
-
- /* signal to make_bfloat() that they're uninitialized: */
- min_key.u64s = max_key.u64s = 0;
-
- t->size = min(bkey_to_cacheline(b, t, btree_bkey_last(b, t)),
- bset_ro_tree_capacity(b, t));
-retry:
- if (t->size < 2) {
- t->size = 0;
- t->extra = BSET_NO_AUX_TREE_VAL;
- 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 */
- eytzinger_for_each(j, t->size) {
- while (bkey_to_cacheline(b, t, k) < cacheline)
- prev = k, k = bkey_next(k);
-
- if (k >= btree_bkey_last(b, t)) {
- t->size--;
- goto retry;
- }
-
- ro_aux_tree_prev(b, t)[j] = prev->u64s;
- bkey_float(b, t, j)->key_offset =
- bkey_to_cacheline_offset(b, t, cacheline++, k);
-
- BUG_ON(tree_to_prev_bkey(b, t, j) != prev);
- BUG_ON(tree_to_bkey(b, t, j) != k);
- }
-
- while (bkey_next(k) != btree_bkey_last(b, t))
- k = bkey_next(k);
-
- t->max_key = bkey_unpack_pos(b, k);
-
- /* Then we build the tree */
- eytzinger_for_each(j, t->size)
- make_bfloat(b, t, j, &min_key, &max_key);
-}
-
-static void bset_alloc_tree(struct btree *b, struct bset_tree *t)
-{
- struct bset_tree *i;
-
- for (i = b->set; i != t; i++)
- BUG_ON(bset_has_rw_aux_tree(i));
-
- bch_bset_set_no_aux_tree(b, t);
-
- /* round up to next cacheline: */
- t->aux_data_offset = round_up(bset_aux_tree_buf_start(b, t),
- SMP_CACHE_BYTES / sizeof(u64));
-
- bset_aux_tree_verify(b);
-}
-
-void bch_bset_build_aux_tree(struct btree *b, struct bset_tree *t,
- bool writeable)
-{
- if (writeable
- ? bset_has_rw_aux_tree(t)
- : bset_has_ro_aux_tree(t))
- return;
-
- bset_alloc_tree(b, t);
-
- if (!__bset_tree_capacity(b, t))
- return;
-
- if (writeable)
- __build_rw_aux_tree(b, t);
- else
- __build_ro_aux_tree(b, t);
-
- bset_aux_tree_verify(b);
-}
-
-void bch_bset_init_first(struct btree *b, struct bset *i)
-{
- struct bset_tree *t;
-
- BUG_ON(b->nsets);
-
- memset(i, 0, sizeof(*i));
- get_random_bytes(&i->seq, sizeof(i->seq));
- SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);
-
- t = &b->set[b->nsets++];
- set_btree_bset(b, t, i);
-}
-
-void bch_bset_init_next(struct btree *b, struct bset *i)
-{
- struct bset_tree *t;
-
- BUG_ON(b->nsets >= MAX_BSETS);
-
- memset(i, 0, sizeof(*i));
- i->seq = btree_bset_first(b)->seq;
- SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);
-
- t = &b->set[b->nsets++];
- set_btree_bset(b, t, i);
-}
-
-static struct bkey_packed *__bkey_prev(struct btree *b, struct bset_tree *t,
- struct bkey_packed *k)
-{
- struct bkey_packed *p;
- unsigned offset;
- int j;
-
- EBUG_ON(k < btree_bkey_first(b, t) ||
- k > btree_bkey_last(b, t));
-
- if (k == btree_bkey_first(b, t))
- return NULL;
-
- switch (bset_aux_tree_type(t)) {
- case BSET_NO_AUX_TREE:
- p = btree_bkey_first(b, t);
- break;
- case BSET_RO_AUX_TREE:
- j = min_t(unsigned, t->size - 1, bkey_to_cacheline(b, t, k));
-
- do {
- p = j ? tree_to_bkey(b, t,
- __inorder_to_eytzinger(j--,
- t->size, t->extra))
- : btree_bkey_first(b, t);
- } while (p >= k);
- break;
- case BSET_RW_AUX_TREE:
- offset = __btree_node_key_to_offset(b, k);
- j = rw_aux_tree_bsearch(b, t, offset);
- p = j ? rw_aux_to_bkey(b, t, j - 1)
- : btree_bkey_first(b, t);
- break;
- }
-
- return p;
-}
-
-struct bkey_packed *bkey_prev_all(struct btree *b, struct bset_tree *t,
- struct bkey_packed *k)
-{
- struct bkey_packed *p;
-
- p = __bkey_prev(b, t, k);
- if (!p)
- return NULL;
-
- while (bkey_next(p) != k)
- p = bkey_next(p);
-
- return p;
-}
-
-struct bkey_packed *bkey_prev(struct btree *b, struct bset_tree *t,
- struct bkey_packed *k)
-{
- while (1) {
- struct bkey_packed *p, *i, *ret = NULL;
-
- p = __bkey_prev(b, t, k);
- if (!p)
- return NULL;
-
- for (i = p; i != k; i = bkey_next(i))
- if (!bkey_deleted(i))
- ret = i;
-
- if (ret)
- return ret;
-
- k = p;
- }
-}
-
-/* Insert */
-
-static void rw_aux_tree_fix_invalidated_key(struct btree *b,
- struct bset_tree *t,
- struct bkey_packed *k)
-{
- unsigned offset = __btree_node_key_to_offset(b, k);
- unsigned j = rw_aux_tree_bsearch(b, t, offset);
-
- if (j < t->size &&
- rw_aux_tree(b, t)[j].offset == offset)
- rw_aux_tree_set(b, t, j, k);
-
- bch_bset_verify_rw_aux_tree(b, t);
-}
-
-static void ro_aux_tree_fix_invalidated_key(struct btree *b,
- struct bset_tree *t,
- struct bkey_packed *k)
-{
- struct bkey_packed min_key, max_key;
- unsigned inorder, j;
-
- BUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
-
- /* signal to make_bfloat() that they're uninitialized: */
- min_key.u64s = max_key.u64s = 0;
-
- if (bkey_next(k) == btree_bkey_last(b, t)) {
- t->max_key = bkey_unpack_pos(b, k);
-
- for (j = 1; j < t->size; j = j * 2 + 1)
- make_bfloat(b, t, j, &min_key, &max_key);
- }
-
- inorder = bkey_to_cacheline(b, t, k);
-
- if (inorder &&
- inorder < t->size) {
- j = __inorder_to_eytzinger(inorder, t->size, t->extra);
-
- if (k == tree_to_bkey(b, t, j)) {
- /* Fix the node this key corresponds to */
- make_bfloat(b, t, j, &min_key, &max_key);
-
- /* Children for which this key is the right boundary */
- for (j = eytzinger_left_child(j);
- j < t->size;
- j = eytzinger_right_child(j))
- make_bfloat(b, t, j, &min_key, &max_key);
- }
- }
-
- if (inorder + 1 < t->size) {
- j = __inorder_to_eytzinger(inorder + 1, t->size, t->extra);
-
- if (k == tree_to_prev_bkey(b, t, j)) {
- make_bfloat(b, t, j, &min_key, &max_key);
-
- /* Children for which this key is the left boundary */
- for (j = eytzinger_right_child(j);
- j < t->size;
- j = eytzinger_left_child(j))
- make_bfloat(b, t, j, &min_key, &max_key);
- }
- }
-}
-
-/**
- * bch_bset_fix_invalidated_key() - given an existing key @k that has been
- * modified, fix any auxiliary search tree by remaking all the nodes in the
- * auxiliary search tree that @k corresponds to
- */
-void bch_bset_fix_invalidated_key(struct btree *b, struct bset_tree *t,
- struct bkey_packed *k)
-{
- switch (bset_aux_tree_type(t)) {
- case BSET_NO_AUX_TREE:
- break;
- case BSET_RO_AUX_TREE:
- ro_aux_tree_fix_invalidated_key(b, t, k);
- break;
- case BSET_RW_AUX_TREE:
- rw_aux_tree_fix_invalidated_key(b, t, k);
- break;
- }
-}
-
-static void bch_bset_fix_lookup_table(struct btree *b,
- struct bset_tree *t,
- struct bkey_packed *_where,
- unsigned clobber_u64s,
- unsigned new_u64s)
-{
- int shift = new_u64s - clobber_u64s;
- unsigned l, j, where = __btree_node_key_to_offset(b, _where);
-
- BUG_ON(bset_has_ro_aux_tree(t));
-
- if (!bset_has_rw_aux_tree(t))
- return;
-
- l = rw_aux_tree_bsearch(b, t, where);
-
- /* l is first >= than @where */
-
- BUG_ON(l < t->size && rw_aux_tree(b, t)[l].offset < where);
- BUG_ON(l && rw_aux_tree(b, t)[l - 1].offset >= where);
-
- if (!l) /* never delete first entry */
- l++;
- else if (l < t->size &&
- where < t->end_offset &&
- rw_aux_tree(b, t)[l].offset == where)
- rw_aux_tree_set(b, t, l++, _where);
-
- /* l now > where */
-
- for (j = l;
- j < t->size &&
- rw_aux_tree(b, t)[j].offset < where + clobber_u64s;
- j++)
- ;
-
- if (j < t->size &&
- rw_aux_tree(b, t)[j].offset + shift ==
- rw_aux_tree(b, t)[l - 1].offset)
- j++;
-
- memmove(&rw_aux_tree(b, t)[l],
- &rw_aux_tree(b, t)[j],
- (void *) &rw_aux_tree(b, t)[t->size] -
- (void *) &rw_aux_tree(b, t)[j]);
- t->size -= j - l;
-
- for (j = l; j < t->size; j++)
- rw_aux_tree(b, t)[j].offset += shift;
-
- BUG_ON(l < t->size &&
- rw_aux_tree(b, t)[l].offset ==
- rw_aux_tree(b, t)[l - 1].offset);
-
- if (t->size < bset_rw_tree_capacity(b, t) &&
- (l < t->size
- ? rw_aux_tree(b, t)[l].offset
- : t->end_offset) -
- rw_aux_tree(b, t)[l - 1].offset >
- L1_CACHE_BYTES / sizeof(u64)) {
- struct bkey_packed *start = rw_aux_to_bkey(b, t, l - 1);
- struct bkey_packed *end = l < t->size
- ? rw_aux_to_bkey(b, t, l)
- : btree_bkey_last(b, t);
- struct bkey_packed *k = start;
-
- while (1) {
- k = bkey_next(k);
- if (k == end)
- break;
-
- if ((void *) k - (void *) start >= L1_CACHE_BYTES) {
- memmove(&rw_aux_tree(b, t)[l + 1],
- &rw_aux_tree(b, t)[l],
- (void *) &rw_aux_tree(b, t)[t->size] -
- (void *) &rw_aux_tree(b, t)[l]);
- t->size++;
- rw_aux_tree_set(b, t, l, k);
- break;
- }
- }
- }
-
- bch_bset_verify_rw_aux_tree(b, t);
- bset_aux_tree_verify(b);
-}
-
-void bch_bset_insert(struct btree *b,
- struct btree_node_iter *iter,
- struct bkey_packed *where,
- struct bkey_i *insert,
- unsigned clobber_u64s)
-{
- struct bkey_format *f = &b->format;
- struct bset_tree *t = bset_tree_last(b);
- struct bkey_packed packed, *src = bkey_to_packed(insert);
-
- bch_bset_verify_rw_aux_tree(b, t);
-
- if (bkey_pack_key(&packed, &insert->k, f))
- src = &packed;
-
- if (!bkey_whiteout(&insert->k))
- btree_keys_account_key_add(&b->nr, t - b->set, src);
-
- if (src->u64s != clobber_u64s) {
- u64 *src_p = where->_data + clobber_u64s;
- u64 *dst_p = where->_data + src->u64s;
-
- BUG_ON((int) le16_to_cpu(bset(b, t)->u64s) <
- (int) clobber_u64s - src->u64s);
-
- memmove_u64s(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);
- le16_add_cpu(&bset(b, t)->u64s, src->u64s - clobber_u64s);
- set_btree_bset_end(b, t);
- }
-
- memcpy_u64s(where, src,
- bkeyp_key_u64s(f, src));
- memcpy_u64s(bkeyp_val(f, where), &insert->v,
- bkeyp_val_u64s(f, src));
-
- bch_bset_fix_lookup_table(b, t, where, clobber_u64s, src->u64s);
-
- bch_verify_key_order(b, iter, where);
- bch_verify_btree_nr_keys(b);
-}
-
-void bch_bset_delete(struct btree *b,
- struct bkey_packed *where,
- unsigned clobber_u64s)
-{
- struct bset_tree *t = bset_tree_last(b);
- u64 *src_p = where->_data + clobber_u64s;
- u64 *dst_p = where->_data;
-
- bch_bset_verify_rw_aux_tree(b, t);
-
- BUG_ON(le16_to_cpu(bset(b, t)->u64s) < clobber_u64s);
-
- memmove_u64s_down(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);
- le16_add_cpu(&bset(b, t)->u64s, -clobber_u64s);
- set_btree_bset_end(b, t);
-
- bch_bset_fix_lookup_table(b, t, where, clobber_u64s, 0);
-}
-
-/* Lookup */
-
-__flatten
-static struct bkey_packed *bset_search_write_set(const struct btree *b,
- struct bset_tree *t,
- struct bpos search,
- const struct bkey_packed *packed_search)
-{
- unsigned l = 0, r = t->size;
-
- while (l + 1 != r) {
- unsigned m = (l + r) >> 1;
-
- if (bkey_cmp(rw_aux_tree(b, t)[m].k, search) < 0)
- l = m;
- else
- r = m;
- }
-
- return rw_aux_to_bkey(b, t, l);
-}
-
-noinline
-static int bset_search_tree_slowpath(const struct btree *b,
- struct bset_tree *t, struct bpos *search,
- const struct bkey_packed *packed_search,
- unsigned n)
-{
- return bkey_cmp_p_or_unp(b, tree_to_bkey(b, t, n),
- packed_search, search) < 0;
-}
-
-__flatten
-static struct bkey_packed *bset_search_tree(const struct btree *b,
- struct bset_tree *t,
- struct bpos search,
- const struct bkey_packed *packed_search)
-{
- struct ro_aux_tree *base = ro_aux_tree_base(b, t);
- struct bkey_float *f = bkey_float_get(base, 1);
- void *p;
- unsigned inorder, n = 1;
-
- while (1) {
- if (likely(n << 4 < t->size)) {
- p = bkey_float_get(base, n << 4);
- prefetch(p);
- } else if (n << 3 < t->size) {
- inorder = __eytzinger_to_inorder(n, t->size, t->extra);
- p = bset_cacheline(b, t, inorder);
-#ifdef CONFIG_X86_64
- asm(".intel_syntax noprefix;"
- "prefetcht0 [%0 - 127 + 64 * 0];"
- "prefetcht0 [%0 - 127 + 64 * 1];"
- "prefetcht0 [%0 - 127 + 64 * 2];"
- "prefetcht0 [%0 - 127 + 64 * 3];"
- ".att_syntax prefix;"
- :
- : "r" (p + 127));
-#else
- prefetch(p + L1_CACHE_BYTES * 0);
- prefetch(p + L1_CACHE_BYTES * 1);
- prefetch(p + L1_CACHE_BYTES * 2);
- prefetch(p + L1_CACHE_BYTES * 3);
-#endif
- } else if (n >= t->size)
- break;
-
- f = bkey_float_get(base, n);
-
- if (packed_search &&
- likely(f->exponent < BFLOAT_FAILED))
- n = n * 2 + (bfloat_mantissa(f, n) <
- bkey_mantissa(packed_search, f, n));
- else
- n = n * 2 + bset_search_tree_slowpath(b, t,
- &search, packed_search, n);
- } while (n < t->size);
-
- inorder = __eytzinger_to_inorder(n >> 1, t->size, t->extra);
-
- /*
- * n would have been the node we recursed to - the low bit tells us if
- * we recursed left or recursed right.
- */
- if (n & 1) {
- return cacheline_to_bkey(b, t, inorder, f->key_offset);
- } else {
- if (--inorder) {
- n = eytzinger_prev(n >> 1, t->size);
- f = bkey_float_get(base, n);
- return cacheline_to_bkey(b, t, inorder, f->key_offset);
- } else
- return btree_bkey_first(b, t);
- }
-}
-
-/*
- * Returns the first key greater than or equal to @search
- */
-__always_inline __flatten
-static struct bkey_packed *bch_bset_search(struct btree *b,
- struct bset_tree *t,
- struct bpos search,
- struct bkey_packed *packed_search,
- const struct bkey_packed *lossy_packed_search,
- bool strictly_greater)
-{
- struct bkey_packed *m;
-
- /*
- * 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()
- */
-
- switch (bset_aux_tree_type(t)) {
- case BSET_NO_AUX_TREE:
- m = btree_bkey_first(b, t);
- break;
- case BSET_RW_AUX_TREE:
- m = bset_search_write_set(b, t, search, lossy_packed_search);
- break;
- case BSET_RO_AUX_TREE:
- /*
- * 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 (bkey_cmp(search, t->max_key) > 0)
- return btree_bkey_last(b, t);
-
- m = bset_search_tree(b, t, search, lossy_packed_search);
- break;
- }
-
- if (lossy_packed_search)
- while (m != btree_bkey_last(b, t) &&
- !btree_iter_pos_cmp_p_or_unp(b, search, lossy_packed_search,
- m, strictly_greater))
- m = bkey_next(m);
-
- if (!packed_search)
- while (m != btree_bkey_last(b, t) &&
- !btree_iter_pos_cmp_packed(b, &search, m, strictly_greater))
- m = bkey_next(m);
-
- if (IS_ENABLED(CONFIG_BCACHE_DEBUG)) {
- struct bkey_packed *prev = bkey_prev_all(b, t, m);
-
- BUG_ON(prev &&
- btree_iter_pos_cmp_p_or_unp(b, search, packed_search,
- prev, strictly_greater));
- }
-
- return m;
-}
-
-/* Btree node iterator */
-
-void bch_btree_node_iter_push(struct btree_node_iter *iter,
- struct btree *b,
- const struct bkey_packed *k,
- const struct bkey_packed *end)
-{
- if (k != end) {
- struct btree_node_iter_set *pos, n =
- ((struct btree_node_iter_set) {
- __btree_node_key_to_offset(b, k),
- __btree_node_key_to_offset(b, end)
- });
-
- btree_node_iter_for_each(iter, pos)
- if (btree_node_iter_cmp(iter, b, n, *pos) <= 0)
- break;
-
- memmove(pos + 1, pos,
- (void *) (iter->data + iter->used) - (void *) pos);
- iter->used++;
- *pos = n;
- }
-}
-
-noinline __flatten __attribute__((cold))
-static void btree_node_iter_init_pack_failed(struct btree_node_iter *iter,
- struct btree *b, struct bpos search,
- bool strictly_greater, bool is_extents)
-{
- struct bset_tree *t;
-
- trace_bkey_pack_pos_fail(search);
-
- for_each_bset(b, t)
- __bch_btree_node_iter_push(iter, b,
- bch_bset_search(b, t, search, NULL, NULL,
- strictly_greater),
- btree_bkey_last(b, t));
-
- bch_btree_node_iter_sort(iter, b);
-}
-
-/**
- * bch_btree_node_iter_init - initialize a btree node iterator, starting from a
- * given position
- *
- * Main entry point to the lookup code for individual btree nodes:
- *
- * NOTE:
- *
- * When you don't filter out deleted keys, btree nodes _do_ contain duplicate
- * keys. This doesn't matter for most code, but it does matter for lookups.
- *
- * Some adjacent keys with a string of equal keys:
- * i j k k k k l m
- *
- * If you search for k, the lookup code isn't guaranteed to return you any
- * specific k. The lookup code is conceptually doing a binary search and
- * iterating backwards is very expensive so if the pivot happens to land at the
- * last k that's what you'll get.
- *
- * This works out ok, but it's something to be aware of:
- *
- * - For non extents, we guarantee that the live key comes last - see
- * btree_node_iter_cmp(), keys_out_of_order(). So the duplicates you don't
- * see will only be deleted keys you don't care about.
- *
- * - For extents, deleted keys sort last (see the comment at the top of this
- * file). But when you're searching for extents, you actually want the first
- * key strictly greater than your search key - an extent that compares equal
- * to the search key is going to have 0 sectors after the search key.
- *
- * But this does mean that we can't just search for
- * bkey_successor(start_of_range) to get the first extent that overlaps with
- * the range we want - if we're unlucky and there's an extent that ends
- * exactly where we searched, then there could be a deleted key at the same
- * position and we'd get that when we search instead of the preceding extent
- * we needed.
- *
- * So we've got to search for start_of_range, then after the lookup iterate
- * past any extents that compare equal to the position we searched for.
- */
-void bch_btree_node_iter_init(struct btree_node_iter *iter,
- struct btree *b, struct bpos search,
- bool strictly_greater, bool is_extents)
-{
- struct bset_tree *t;
- struct bkey_packed p, *packed_search = NULL;
-
- EBUG_ON(bkey_cmp(search, b->data->min_key) < 0);
- bset_aux_tree_verify(b);
-
- __bch_btree_node_iter_init(iter, is_extents);
-
- //if (bkey_cmp(search, b->curr_max_key) > 0)
- // return;
-
- switch (bkey_pack_pos_lossy(&p, search, b)) {
- case BKEY_PACK_POS_EXACT:
- packed_search = &p;
- break;
- case BKEY_PACK_POS_SMALLER:
- packed_search = NULL;
- break;
- case BKEY_PACK_POS_FAIL:
- btree_node_iter_init_pack_failed(iter, b, search,
- strictly_greater, is_extents);
- return;
- }
-
- for_each_bset(b, t)
- __bch_btree_node_iter_push(iter, b,
- bch_bset_search(b, t, search,
- packed_search, &p,
- strictly_greater),
- btree_bkey_last(b, t));
-
- bch_btree_node_iter_sort(iter, b);
-}
-
-void bch_btree_node_iter_init_from_start(struct btree_node_iter *iter,
- struct btree *b,
- bool is_extents)
-{
- struct bset_tree *t;
-
- __bch_btree_node_iter_init(iter, is_extents);
-
- for_each_bset(b, t)
- __bch_btree_node_iter_push(iter, b,
- btree_bkey_first(b, t),
- btree_bkey_last(b, t));
- bch_btree_node_iter_sort(iter, b);
-}
-
-struct bkey_packed *bch_btree_node_iter_bset_pos(struct btree_node_iter *iter,
- struct btree *b,
- struct bset_tree *t)
-{
- struct btree_node_iter_set *set;
-
- BUG_ON(iter->used > MAX_BSETS);
-
- btree_node_iter_for_each(iter, set)
- if (set->end == t->end_offset)
- return __btree_node_offset_to_key(b, set->k);
-
- return btree_bkey_last(b, t);
-}
-
-static inline void btree_node_iter_sift(struct btree_node_iter *iter,
- struct btree *b,
- unsigned start)
-{
- unsigned i;
-
- EBUG_ON(iter->used > MAX_BSETS);
-
- for (i = start;
- i + 1 < iter->used &&
- btree_node_iter_cmp(iter, b, iter->data[i], iter->data[i + 1]) > 0;
- i++)
- swap(iter->data[i], iter->data[i + 1]);
-}
-
-static inline void btree_node_iter_sort_two(struct btree_node_iter *iter,
- struct btree *b,
- unsigned first)
-{
- if (btree_node_iter_cmp(iter, b,
- iter->data[first],
- iter->data[first + 1]) > 0)
- swap(iter->data[first], iter->data[first + 1]);
-}
-
-void bch_btree_node_iter_sort(struct btree_node_iter *iter,
- struct btree *b)
-{
- EBUG_ON(iter->used > 3);
-
- /* unrolled bubble sort: */
-
- if (iter->used > 2) {
- btree_node_iter_sort_two(iter, b, 0);
- btree_node_iter_sort_two(iter, b, 1);
- }
-
- if (iter->used > 1)
- btree_node_iter_sort_two(iter, b, 0);
-}
-EXPORT_SYMBOL(bch_btree_node_iter_sort);
-
-/**
- * bch_btree_node_iter_advance - advance @iter by one key
- *
- * Doesn't do debugchecks - for cases where (insert_fixup_extent()) a bset might
- * momentarily have out of order extents.
- */
-void bch_btree_node_iter_advance(struct btree_node_iter *iter,
- struct btree *b)
-{
- struct bkey_packed *k = bch_btree_node_iter_peek_all(iter, b);
-
- iter->data->k += __bch_btree_node_iter_peek_all(iter, b)->u64s;
-
- BUG_ON(iter->data->k > iter->data->end);
-
- if (iter->data->k == iter->data->end) {
- BUG_ON(iter->used == 0);
- iter->data[0] = iter->data[--iter->used];
- }
-
- btree_node_iter_sift(iter, b, 0);
-
- bch_btree_node_iter_next_check(iter, b, k);
-}
-
-/*
- * Expensive:
- */
-struct bkey_packed *bch_btree_node_iter_prev_all(struct btree_node_iter *iter,
- struct btree *b)
-{
- struct bkey_packed *k, *prev = NULL;
- struct btree_node_iter_set *set;
- struct bset_tree *t;
- struct bset_tree *prev_t;
- unsigned end;
-
- bch_btree_node_iter_verify(iter, b);
-
- for_each_bset(b, t) {
- k = bkey_prev_all(b, t,
- bch_btree_node_iter_bset_pos(iter, b, t));
- if (k &&
- (!prev || __btree_node_iter_cmp(iter->is_extents, b,
- k, prev) > 0)) {
- prev = k;
- prev_t = t;
- }
- }
-
- if (!prev)
- return NULL;
-
- /*
- * We're manually memmoving instead of just calling sort() to ensure the
- * prev we picked ends up in slot 0 - sort won't necessarily put it
- * there because of duplicate deleted keys:
- */
- end = __btree_node_key_to_offset(b, btree_bkey_last(b, prev_t));
- btree_node_iter_for_each(iter, set)
- if (set->end == end) {
- memmove(&iter->data[1],
- &iter->data[0],
- (void *) set - (void *) &iter->data[0]);
- goto out;
- }
-
- memmove(&iter->data[1],
- &iter->data[0],
- (void *) &iter->data[iter->used] - (void *) &iter->data[0]);
- iter->used++;
-out:
- iter->data[0].k = __btree_node_key_to_offset(b, prev);
- iter->data[0].end = end;
- return prev;
-}
-
-struct bkey_packed *bch_btree_node_iter_prev(struct btree_node_iter *iter,
- struct btree *b)
-{
- struct bkey_packed *k;
-
- do {
- k = bch_btree_node_iter_prev_all(iter, b);
- } while (k && bkey_deleted(k));
-
- return k;
-}
-
-struct bkey_s_c bch_btree_node_iter_peek_unpack(struct btree_node_iter *iter,
- struct btree *b,
- struct bkey *u)
-{
- struct bkey_packed *k = bch_btree_node_iter_peek(iter, b);
-
- return k ? bkey_disassemble(b, k, u) : bkey_s_c_null;
-}
-EXPORT_SYMBOL(bch_btree_node_iter_peek_unpack);
-
-/* Mergesort */
-
-void bch_btree_keys_stats(struct btree *b, struct bset_stats *stats)
-{
- struct bset_tree *t;
-
- for_each_bset(b, t) {
- enum bset_aux_tree_type type = bset_aux_tree_type(t);
- size_t j;
-
- stats->sets[type].nr++;
- stats->sets[type].bytes += le16_to_cpu(bset(b, t)->u64s) *
- sizeof(u64);
-
- if (bset_has_ro_aux_tree(t)) {
- stats->floats += t->size - 1;
-
- for (j = 1; j < t->size; j++)
- switch (bkey_float(b, t, j)->exponent) {
- case BFLOAT_FAILED_UNPACKED:
- stats->failed_unpacked++;
- break;
- case BFLOAT_FAILED_PREV:
- stats->failed_prev++;
- break;
- case BFLOAT_FAILED_OVERFLOW:
- stats->failed_overflow++;
- break;
- }
- }
- }
-}
-
-int bch_bkey_print_bfloat(struct btree *b, struct bkey_packed *k,
- char *buf, size_t size)
-{
- struct bset_tree *t = bch_bkey_to_bset(b, k);
- struct bkey_packed *l, *r, *p;
- struct bkey uk, up;
- char buf1[200], buf2[200];
- unsigned j;
-
- if (!size)
- return 0;
-
- if (!bset_has_ro_aux_tree(t))
- goto out;
-
- j = __inorder_to_eytzinger(bkey_to_cacheline(b, t, k), t->size, t->extra);
- if (j &&
- j < t->size &&
- k == tree_to_bkey(b, t, j))
- switch (bkey_float(b, t, j)->exponent) {
- case BFLOAT_FAILED_UNPACKED:
- uk = bkey_unpack_key(b, k);
- return scnprintf(buf, size,
- " failed unpacked at depth %u\n"
- "\t%llu:%llu\n",
- ilog2(j),
- uk.p.inode, uk.p.offset);
- case BFLOAT_FAILED_PREV:
- p = tree_to_prev_bkey(b, t, j);
- l = is_power_of_2(j)
- ? btree_bkey_first(b, t)
- : tree_to_prev_bkey(b, t, j >> ffs(j));
- r = is_power_of_2(j + 1)
- ? bkey_prev_all(b, t, btree_bkey_last(b, t))
- : tree_to_bkey(b, t, j >> (ffz(j) + 1));
-
- up = bkey_unpack_key(b, p);
- uk = bkey_unpack_key(b, k);
- bch_to_binary(buf1, high_word(&b->format, p), b->nr_key_bits);
- bch_to_binary(buf2, high_word(&b->format, k), b->nr_key_bits);
-
- return scnprintf(buf, size,
- " failed prev at depth %u\n"
- "\tkey starts at bit %u but first differing bit at %u\n"
- "\t%llu:%llu\n"
- "\t%llu:%llu\n"
- "\t%s\n"
- "\t%s\n",
- ilog2(j),
- bkey_greatest_differing_bit(b, l, r),
- bkey_greatest_differing_bit(b, p, k),
- uk.p.inode, uk.p.offset,
- up.p.inode, up.p.offset,
- buf1, buf2);
- case BFLOAT_FAILED_OVERFLOW:
- uk = bkey_unpack_key(b, k);
- return scnprintf(buf, size,
- " failed overflow at depth %u\n"
- "\t%llu:%llu\n",
- ilog2(j),
- uk.p.inode, uk.p.offset);
- }
-out:
- *buf = '\0';
- return 0;
-}
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-02 22:01:24 +0000