Orange Pi5 kernel

// 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, __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 int set)
{
<------>struct bkey *k, *next;
 
<------>for (k = i->start; k < bset_bkey_last(i); k = next) {
<------><------>next = bkey_next(k);
 
<------><------>pr_err("block %u key %u/%u: ", set,
<------><------>       (unsigned int) ((u64 *) k - i->d), i->keys);
 
<------><------>if (b->ops->key_dump)
<------><------><------>b->ops->key_dump(b, k);
<------><------>else
<------><------><------>pr_cont("%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)
<------><------><------>pr_err("Key skipped backwards\n");
<------>}
}
 
void bch_dump_bucket(struct btree_keys *b)
{
<------>unsigned int 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 int 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 int 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;
}
 
/* Pop the top key of keylist by pointing l->top to its previous key */
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;
}
 
/* Pop the bottom key of keylist and update l->top_p */
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 int 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 int 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 int 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 int	exponent:BKEY_EXPONENT_BITS;
<------>unsigned int	m:BKEY_MID_BITS;
<------>unsigned int	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;
}
 
int bch_btree_keys_alloc(struct btree_keys *b,
<------><------><------> unsigned int 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_COMP|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;
}
 
void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
<------><------><------> bool *expensive_debug_checks)
{
<------>b->ops = ops;
<------>b->expensive_debug_checks = expensive_debug_checks;
<------>b->nsets = 0;
<------>b->last_set_unwritten = 0;
 
<------>/*
<------> * struct btree_keys in embedded in struct btree, and struct
<------> * bset_tree is embedded into struct btree_keys. They are all
<------> * initialized as 0 by kzalloc() in mca_bucket_alloc(), and
<------> * b->set[0].data is allocated in bch_btree_keys_alloc(), so we
<------> * don't have to initiate b->set[].size and b->set[].data here
<------> * any more.
<------> */
}
 
/* Binary tree stuff for auxiliary search trees */
 
/*
 * return array index next to j when does in-order traverse
 * of a binary tree which is stored in a linear array
 */
static unsigned int inorder_next(unsigned int j, unsigned int size)
{
<------>if (j * 2 + 1 < size) {
<------><------>j = j * 2 + 1;
 
<------><------>while (j * 2 < size)
<------><------><------>j *= 2;
<------>} else
<------><------>j >>= ffz(j) + 1;
 
<------>return j;
}
 
/*
 * return array index previous to j when does in-order traverse
 * of a binary tree which is stored in a linear array
 */
static unsigned int inorder_prev(unsigned int j, unsigned int 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 int __to_inorder(unsigned int j,
<------><------><------><------>  unsigned int size,
<------><------><------><------>  unsigned int extra)
{
<------>unsigned int b = fls(j);
<------>unsigned int shift = fls(size - 1) - b;
 
<------>j  ^= 1U << (b - 1);
<------>j <<= 1;
<------>j  |= 1;
<------>j <<= shift;
 
<------>if (j > extra)
<------><------>j -= (j - extra) >> 1;
 
<------>return j;
}
 
/*
 * Return the cacheline index in bset_tree->data, where j is index
 * from a linear array which stores the auxiliar binary tree
 */
static unsigned int to_inorder(unsigned int j, struct bset_tree *t)
{
<------>return __to_inorder(j, t->size, t->extra);
}
 
static unsigned int __inorder_to_tree(unsigned int j,
<------><------><------><------>      unsigned int size,
<------><------><------><------>      unsigned int extra)
{
<------>unsigned int shift;
 
<------>if (j > extra)
<------><------>j += j - extra;
 
<------>shift = ffs(j);
 
<------>j >>= shift;
<------>j  |= roundup_pow_of_two(size) >> shift;
 
<------>return j;
}
 
/*
 * Return an index from a linear array which stores the auxiliar binary
 * tree, j is the cacheline index of t->data.
 */
static unsigned int inorder_to_tree(unsigned int 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 int size = 2;
<------>     size < 65536000;
<------>     size++) {
<------><------>unsigned int extra =
<------><------><------>(size - rounddown_pow_of_two(size - 1)) << 1;
<------><------>unsigned int i = 1, j = rounddown_pow_of_two(size - 1);
 
<------><------>if (!(size % 4096))
<------><------><------>pr_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 int cacheline,
<------><------><------><------>      unsigned int offset)
{
<------>return ((void *) t->data) + cacheline * BSET_CACHELINE + offset * 8;
}
 
static unsigned int bkey_to_cacheline(struct bset_tree *t, struct bkey *k)
{
<------>return ((void *) k - (void *) t->data) / BSET_CACHELINE;
}
 
static unsigned int bkey_to_cacheline_offset(struct bset_tree *t,
<------><------><------><------><------> unsigned int 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 int 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 int 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 int 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;
}
 
/*
 * Calculate mantissa value for struct bkey_float.
 * If most significant bit of f->exponent is not set, then
 *  - f->exponent >> 6 is 0
 *  - p[0] points to bkey->low
 *  - p[-1] borrows bits from KEY_INODE() of bkey->high
 * if most isgnificant bits of f->exponent is set, then
 *  - f->exponent >> 6 is 1
 *  - p[0] points to bits from KEY_INODE() of bkey->high
 *  - p[-1] points to other bits from KEY_INODE() of
 *    bkey->high too.
 * See make_bfloat() to check when most significant bit of f->exponent
 * is set or not.
 */
static inline unsigned int 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 int 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 l and r have different KEY_INODE values (different backing
<------> * device), f->exponent records how many least significant bits
<------> * are different in KEY_INODE values and sets most significant
<------> * bits to 1 (by +64).
<------> * If l and r have same KEY_INODE value, f->exponent records
<------> * how many different bits in least significant bits of bkey->low.
<------> * See bfloat_mantiss() how the most significant bit of
<------> * f->exponent is used to calculate bfloat mantissa value.
<------> */
<------>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 int 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);
}
 
/*
 * Build auxiliary binary tree 'struct bset_tree *t', this tree is used to
 * accelerate bkey search in a btree node (pointed by bset_tree->data in
 * memory). After search in the auxiliar tree by calling bset_search_tree(),
 * a struct bset_search_iter is returned which indicates range [l, r] from
 * bset_tree->data where the searching bkey might be inside. Then a followed
 * linear comparison does the exact search, see __bch_bset_search() for how
 * the auxiliary tree is used.
 */
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 int j, cacheline = 1;
 
<------>b->last_set_unwritten = 0;
 
<------>bset_alloc_tree(b, t);
 
<------>t->size = min_t(unsigned int,
<------><------><------>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);
}
 
/* Insert */
 
void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k)
{
<------>struct bset_tree *t;
<------>unsigned int 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);
}
 
static void bch_bset_fix_lookup_table(struct btree_keys *b,
<------><------><------><------>      struct bset_tree *t,
<------><------><------><------>      struct bkey *k)
{
<------>unsigned int shift = bkey_u64s(k);
<------>unsigned int 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);
}
 
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);
}
 
unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
<------><------><------>      struct bkey *replace_key)
{
<------>unsigned int status = BTREE_INSERT_STATUS_NO_INSERT;
<------>struct bset *i = bset_tree_last(b)->data;
<------>struct bkey *m, *prev = NULL;
<------>struct btree_iter iter;
<------>struct bkey preceding_key_on_stack = ZERO_KEY;
<------>struct bkey *preceding_key_p = &preceding_key_on_stack;
 
<------>BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
 
<------>/*
<------> * If k has preceding key, preceding_key_p will be set to address
<------> *  of k's preceding key; otherwise preceding_key_p will be set
<------> * to NULL inside preceding_key().
<------> */
<------>if (b->ops->is_extents)
<------><------>preceding_key(&START_KEY(k), &preceding_key_p);
<------>else
<------><------>preceding_key(k, &preceding_key_p);
 
<------>m = bch_btree_iter_init(b, &iter, preceding_key_p);
 
<------>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;
}
 
/* 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 int li = 0, ri = t->size;
 
<------>while (li + 1 != ri) {
<------><------>unsigned int 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 int inorder, j, n = 1;
 
<------>do {
<------><------>unsigned int p = n << 4;
 
<------><------>if (p < t->size)
<------><------><------>prefetch(&t->tree[p]);
 
<------><------>j = n;
<------><------>f = &t->tree[j];
 
<------><------>if (likely(f->exponent != 127)) {
<------><------><------>if (f->mantissa >= bfloat_mantissa(search, f))
<------><------><------><------>n = j * 2;
<------><------><------>else
<------><------><------><------>n = j * 2 + 1;
<------><------>} else {
<------><------><------>if (bkey_cmp(tree_to_bkey(t, j), search) > 0)
<------><------><------><------>n = j * 2;
<------><------><------>else
<------><------><------><------>n = 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;
}
 
/* 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);
}
 
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);
 
}
 
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)
{
<------>mempool_exit(&state->pool);
}
 
int bch_bset_sort_state_init(struct bset_sort_state *state,
<------><------><------>     unsigned int page_order)
{
<------>spin_lock_init(&state->time.lock);
 
<------>state->page_order = page_order;
<------>state->crit_factor = int_sqrt(1 << page_order);
 
<------>return mempool_init_page_pool(&state->pool, 1, page_order);
}
 
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\n", out->keys);
}
 
static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
<------><------><------> unsigned int start, unsigned int 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()
<------><------> *
<------><------> * Don't worry event 'out' is allocated from mempool, it can
<------><------> * still be swapped here. Because state->pool is a page mempool
<------><------> * creaated by by mempool_init_page_pool(), which allocates
<------><------> * pages by alloc_pages() indeed.
<------><------> */
 
<------><------>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 int 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 int 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);
}
 
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 int 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);
}
 
void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats)
{
<------>unsigned int 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;
<------><------>}
<------>}
}