drivers/md/bcache/bset.c

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This source file includes following definitions.
bch_dump_bset
bch_dump_bucket
__bch_count_data
__bch_check_keys
bch_btree_iter_next_check
bch_btree_iter_next_check
__bch_keylist_realloc
bch_keylist_pop
bch_keylist_pop_front
bch_bkey_copy_single_ptr
__bch_cut_front
__bch_cut_back
btree_keys_bytes
btree_keys_cachelines
bset_tree_bytes
bset_prev_bytes
bch_btree_keys_free
bch_btree_keys_alloc
bch_btree_keys_init
inorder_next
inorder_prev
__to_inorder
to_inorder
__inorder_to_tree
inorder_to_tree
inorder_test
cacheline_to_bkey
bkey_to_cacheline
bkey_to_cacheline_offset
tree_to_bkey
tree_to_prev_bkey
table_to_bkey
shrd128
bfloat_mantissa
make_bfloat
bset_alloc_tree
bch_bset_build_unwritten_tree
bch_bset_init_next
bch_bset_build_written_tree
bch_bset_fix_invalidated_key
bch_bset_fix_lookup_table
bch_bkey_try_merge
bch_bset_insert
bch_btree_insert_key
bset_search_write_set
bset_search_tree
__bch_bset_search
btree_iter_cmp
btree_iter_end
bch_btree_iter_push
__bch_btree_iter_init
bch_btree_iter_init
__bch_btree_iter_next
bch_btree_iter_next
bch_btree_iter_next_filter
bch_bset_sort_state_free
bch_bset_sort_state_init
btree_mergesort
__btree_sort
bch_btree_sort_partial
bch_btree_sort_and_fix_extents
bch_btree_sort_into
bch_btree_sort_lazy
bch_btree_keys_stats
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Code for working with individual keys, and sorted sets of keys with in a
   4  * btree node
   5  *
   6  * Copyright 2012 Google, Inc.
   7  */
   8 
   9 #define pr_fmt(fmt) "bcache: %s() " fmt "\n", __func__
  10 
  11 #include "util.h"
  12 #include "bset.h"
  13 
  14 #include <linux/console.h>
  15 #include <linux/sched/clock.h>
  16 #include <linux/random.h>
  17 #include <linux/prefetch.h>
  18 
  19 #ifdef CONFIG_BCACHE_DEBUG
  20 
  21 void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned int set)
  22 {
  23         struct bkey *k, *next;
  24 
  25         for (k = i->start; k < bset_bkey_last(i); k = next) {
  26                 next = bkey_next(k);
  27 
  28                 pr_err("block %u key %u/%u: ", set,
  29                        (unsigned int) ((u64 *) k - i->d), i->keys);
  30 
  31                 if (b->ops->key_dump)
  32                         b->ops->key_dump(b, k);
  33                 else
  34                         pr_err("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k));
  35 
  36                 if (next < bset_bkey_last(i) &&
  37                     bkey_cmp(k, b->ops->is_extents ?
  38                              &START_KEY(next) : next) > 0)
  39                         pr_err("Key skipped backwards\n");
  40         }
  41 }
  42 
  43 void bch_dump_bucket(struct btree_keys *b)
  44 {
  45         unsigned int i;
  46 
  47         console_lock();
  48         for (i = 0; i <= b->nsets; i++)
  49                 bch_dump_bset(b, b->set[i].data,
  50                               bset_sector_offset(b, b->set[i].data));
  51         console_unlock();
  52 }
  53 
  54 int __bch_count_data(struct btree_keys *b)
  55 {
  56         unsigned int ret = 0;
  57         struct btree_iter iter;
  58         struct bkey *k;
  59 
  60         if (b->ops->is_extents)
  61                 for_each_key(b, k, &iter)
  62                         ret += KEY_SIZE(k);
  63         return ret;
  64 }
  65 
  66 void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
  67 {
  68         va_list args;
  69         struct bkey *k, *p = NULL;
  70         struct btree_iter iter;
  71         const char *err;
  72 
  73         for_each_key(b, k, &iter) {
  74                 if (b->ops->is_extents) {
  75                         err = "Keys out of order";
  76                         if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
  77                                 goto bug;
  78 
  79                         if (bch_ptr_invalid(b, k))
  80                                 continue;
  81 
  82                         err =  "Overlapping keys";
  83                         if (p && bkey_cmp(p, &START_KEY(k)) > 0)
  84                                 goto bug;
  85                 } else {
  86                         if (bch_ptr_bad(b, k))
  87                                 continue;
  88 
  89                         err = "Duplicate keys";
  90                         if (p && !bkey_cmp(p, k))
  91                                 goto bug;
  92                 }
  93                 p = k;
  94         }
  95 #if 0
  96         err = "Key larger than btree node key";
  97         if (p && bkey_cmp(p, &b->key) > 0)
  98                 goto bug;
  99 #endif
 100         return;
 101 bug:
 102         bch_dump_bucket(b);
 103 
 104         va_start(args, fmt);
 105         vprintk(fmt, args);
 106         va_end(args);
 107 
 108         panic("bch_check_keys error:  %s:\n", err);
 109 }
 110 
 111 static void bch_btree_iter_next_check(struct btree_iter *iter)
 112 {
 113         struct bkey *k = iter->data->k, *next = bkey_next(k);
 114 
 115         if (next < iter->data->end &&
 116             bkey_cmp(k, iter->b->ops->is_extents ?
 117                      &START_KEY(next) : next) > 0) {
 118                 bch_dump_bucket(iter->b);
 119                 panic("Key skipped backwards\n");
 120         }
 121 }
 122 
 123 #else
 124 
 125 static inline void bch_btree_iter_next_check(struct btree_iter *iter) {}
 126 
 127 #endif
 128 
 129 /* Keylists */
 130 
 131 int __bch_keylist_realloc(struct keylist *l, unsigned int u64s)
 132 {
 133         size_t oldsize = bch_keylist_nkeys(l);
 134         size_t newsize = oldsize + u64s;
 135         uint64_t *old_keys = l->keys_p == l->inline_keys ? NULL : l->keys_p;
 136         uint64_t *new_keys;
 137 
 138         newsize = roundup_pow_of_two(newsize);
 139 
 140         if (newsize <= KEYLIST_INLINE ||
 141             roundup_pow_of_two(oldsize) == newsize)
 142                 return 0;
 143 
 144         new_keys = krealloc(old_keys, sizeof(uint64_t) * newsize, GFP_NOIO);
 145 
 146         if (!new_keys)
 147                 return -ENOMEM;
 148 
 149         if (!old_keys)
 150                 memcpy(new_keys, l->inline_keys, sizeof(uint64_t) * oldsize);
 151 
 152         l->keys_p = new_keys;
 153         l->top_p = new_keys + oldsize;
 154 
 155         return 0;
 156 }
 157 
 158 struct bkey *bch_keylist_pop(struct keylist *l)
 159 {
 160         struct bkey *k = l->keys;
 161 
 162         if (k == l->top)
 163                 return NULL;
 164 
 165         while (bkey_next(k) != l->top)
 166                 k = bkey_next(k);
 167 
 168         return l->top = k;
 169 }
 170 
 171 void bch_keylist_pop_front(struct keylist *l)
 172 {
 173         l->top_p -= bkey_u64s(l->keys);
 174 
 175         memmove(l->keys,
 176                 bkey_next(l->keys),
 177                 bch_keylist_bytes(l));
 178 }
 179 
 180 /* Key/pointer manipulation */
 181 
 182 void bch_bkey_copy_single_ptr(struct bkey *dest, const struct bkey *src,
 183                               unsigned int i)
 184 {
 185         BUG_ON(i > KEY_PTRS(src));
 186 
 187         /* Only copy the header, key, and one pointer. */
 188         memcpy(dest, src, 2 * sizeof(uint64_t));
 189         dest->ptr[0] = src->ptr[i];
 190         SET_KEY_PTRS(dest, 1);
 191         /* We didn't copy the checksum so clear that bit. */
 192         SET_KEY_CSUM(dest, 0);
 193 }
 194 
 195 bool __bch_cut_front(const struct bkey *where, struct bkey *k)
 196 {
 197         unsigned int i, len = 0;
 198 
 199         if (bkey_cmp(where, &START_KEY(k)) <= 0)
 200                 return false;
 201 
 202         if (bkey_cmp(where, k) < 0)
 203                 len = KEY_OFFSET(k) - KEY_OFFSET(where);
 204         else
 205                 bkey_copy_key(k, where);
 206 
 207         for (i = 0; i < KEY_PTRS(k); i++)
 208                 SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + KEY_SIZE(k) - len);
 209 
 210         BUG_ON(len > KEY_SIZE(k));
 211         SET_KEY_SIZE(k, len);
 212         return true;
 213 }
 214 
 215 bool __bch_cut_back(const struct bkey *where, struct bkey *k)
 216 {
 217         unsigned int len = 0;
 218 
 219         if (bkey_cmp(where, k) >= 0)
 220                 return false;
 221 
 222         BUG_ON(KEY_INODE(where) != KEY_INODE(k));
 223 
 224         if (bkey_cmp(where, &START_KEY(k)) > 0)
 225                 len = KEY_OFFSET(where) - KEY_START(k);
 226 
 227         bkey_copy_key(k, where);
 228 
 229         BUG_ON(len > KEY_SIZE(k));
 230         SET_KEY_SIZE(k, len);
 231         return true;
 232 }
 233 
 234 /* Auxiliary search trees */
 235 
 236 /* 32 bits total: */
 237 #define BKEY_MID_BITS           3
 238 #define BKEY_EXPONENT_BITS      7
 239 #define BKEY_MANTISSA_BITS      (32 - BKEY_MID_BITS - BKEY_EXPONENT_BITS)
 240 #define BKEY_MANTISSA_MASK      ((1 << BKEY_MANTISSA_BITS) - 1)
 241 
 242 struct bkey_float {
 243         unsigned int    exponent:BKEY_EXPONENT_BITS;
 244         unsigned int    m:BKEY_MID_BITS;
 245         unsigned int    mantissa:BKEY_MANTISSA_BITS;
 246 } __packed;
 247 
 248 /*
 249  * BSET_CACHELINE was originally intended to match the hardware cacheline size -
 250  * it used to be 64, but I realized the lookup code would touch slightly less
 251  * memory if it was 128.
 252  *
 253  * It definites the number of bytes (in struct bset) per struct bkey_float in
 254  * the auxiliar search tree - when we're done searching the bset_float tree we
 255  * have this many bytes left that we do a linear search over.
 256  *
 257  * Since (after level 5) every level of the bset_tree is on a new cacheline,
 258  * we're touching one fewer cacheline in the bset tree in exchange for one more
 259  * cacheline in the linear search - but the linear search might stop before it
 260  * gets to the second cacheline.
 261  */
 262 
 263 #define BSET_CACHELINE          128
 264 
 265 /* Space required for the btree node keys */
 266 static inline size_t btree_keys_bytes(struct btree_keys *b)
 267 {
 268         return PAGE_SIZE << b->page_order;
 269 }
 270 
 271 static inline size_t btree_keys_cachelines(struct btree_keys *b)
 272 {
 273         return btree_keys_bytes(b) / BSET_CACHELINE;
 274 }
 275 
 276 /* Space required for the auxiliary search trees */
 277 static inline size_t bset_tree_bytes(struct btree_keys *b)
 278 {
 279         return btree_keys_cachelines(b) * sizeof(struct bkey_float);
 280 }
 281 
 282 /* Space required for the prev pointers */
 283 static inline size_t bset_prev_bytes(struct btree_keys *b)
 284 {
 285         return btree_keys_cachelines(b) * sizeof(uint8_t);
 286 }
 287 
 288 /* Memory allocation */
 289 
 290 void bch_btree_keys_free(struct btree_keys *b)
 291 {
 292         struct bset_tree *t = b->set;
 293 
 294         if (bset_prev_bytes(b) < PAGE_SIZE)
 295                 kfree(t->prev);
 296         else
 297                 free_pages((unsigned long) t->prev,
 298                            get_order(bset_prev_bytes(b)));
 299 
 300         if (bset_tree_bytes(b) < PAGE_SIZE)
 301                 kfree(t->tree);
 302         else
 303                 free_pages((unsigned long) t->tree,
 304                            get_order(bset_tree_bytes(b)));
 305 
 306         free_pages((unsigned long) t->data, b->page_order);
 307 
 308         t->prev = NULL;
 309         t->tree = NULL;
 310         t->data = NULL;
 311 }
 312 EXPORT_SYMBOL(bch_btree_keys_free);
 313 
 314 int bch_btree_keys_alloc(struct btree_keys *b,
 315                          unsigned int page_order,
 316                          gfp_t gfp)
 317 {
 318         struct bset_tree *t = b->set;
 319 
 320         BUG_ON(t->data);
 321 
 322         b->page_order = page_order;
 323 
 324         t->data = (void *) __get_free_pages(gfp, b->page_order);
 325         if (!t->data)
 326                 goto err;
 327 
 328         t->tree = bset_tree_bytes(b) < PAGE_SIZE
 329                 ? kmalloc(bset_tree_bytes(b), gfp)
 330                 : (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b)));
 331         if (!t->tree)
 332                 goto err;
 333 
 334         t->prev = bset_prev_bytes(b) < PAGE_SIZE
 335                 ? kmalloc(bset_prev_bytes(b), gfp)
 336                 : (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b)));
 337         if (!t->prev)
 338                 goto err;
 339 
 340         return 0;
 341 err:
 342         bch_btree_keys_free(b);
 343         return -ENOMEM;
 344 }
 345 EXPORT_SYMBOL(bch_btree_keys_alloc);
 346 
 347 void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
 348                          bool *expensive_debug_checks)
 349 {
 350         b->ops = ops;
 351         b->expensive_debug_checks = expensive_debug_checks;
 352         b->nsets = 0;
 353         b->last_set_unwritten = 0;
 354 
 355         /*
 356          * struct btree_keys in embedded in struct btree, and struct
 357          * bset_tree is embedded into struct btree_keys. They are all
 358          * initialized as 0 by kzalloc() in mca_bucket_alloc(), and
 359          * b->set[0].data is allocated in bch_btree_keys_alloc(), so we
 360          * don't have to initiate b->set[].size and b->set[].data here
 361          * any more.
 362          */
 363 }
 364 EXPORT_SYMBOL(bch_btree_keys_init);
 365 
 366 /* Binary tree stuff for auxiliary search trees */
 367 
 368 /*
 369  * return array index next to j when does in-order traverse
 370  * of a binary tree which is stored in a linear array
 371  */
 372 static unsigned int inorder_next(unsigned int j, unsigned int size)
 373 {
 374         if (j * 2 + 1 < size) {
 375                 j = j * 2 + 1;
 376 
 377                 while (j * 2 < size)
 378                         j *= 2;
 379         } else
 380                 j >>= ffz(j) + 1;
 381 
 382         return j;
 383 }
 384 
 385 /*
 386  * return array index previous to j when does in-order traverse
 387  * of a binary tree which is stored in a linear array
 388  */
 389 static unsigned int inorder_prev(unsigned int j, unsigned int size)
 390 {
 391         if (j * 2 < size) {
 392                 j = j * 2;
 393 
 394                 while (j * 2 + 1 < size)
 395                         j = j * 2 + 1;
 396         } else
 397                 j >>= ffs(j);
 398 
 399         return j;
 400 }
 401 
 402 /*
 403  * I have no idea why this code works... and I'm the one who wrote it
 404  *
 405  * However, I do know what it does:
 406  * Given a binary tree constructed in an array (i.e. how you normally implement
 407  * a heap), it converts a node in the tree - referenced by array index - to the
 408  * index it would have if you did an inorder traversal.
 409  *
 410  * Also tested for every j, size up to size somewhere around 6 million.
 411  *
 412  * The binary tree starts at array index 1, not 0
 413  * extra is a function of size:
 414  *   extra = (size - rounddown_pow_of_two(size - 1)) << 1;
 415  */
 416 static unsigned int __to_inorder(unsigned int j,
 417                                   unsigned int size,
 418                                   unsigned int extra)
 419 {
 420         unsigned int b = fls(j);
 421         unsigned int shift = fls(size - 1) - b;
 422 
 423         j  ^= 1U << (b - 1);
 424         j <<= 1;
 425         j  |= 1;
 426         j <<= shift;
 427 
 428         if (j > extra)
 429                 j -= (j - extra) >> 1;
 430 
 431         return j;
 432 }
 433 
 434 /*
 435  * Return the cacheline index in bset_tree->data, where j is index
 436  * from a linear array which stores the auxiliar binary tree
 437  */
 438 static unsigned int to_inorder(unsigned int j, struct bset_tree *t)
 439 {
 440         return __to_inorder(j, t->size, t->extra);
 441 }
 442 
 443 static unsigned int __inorder_to_tree(unsigned int j,
 444                                       unsigned int size,
 445                                       unsigned int extra)
 446 {
 447         unsigned int shift;
 448 
 449         if (j > extra)
 450                 j += j - extra;
 451 
 452         shift = ffs(j);
 453 
 454         j >>= shift;
 455         j  |= roundup_pow_of_two(size) >> shift;
 456 
 457         return j;
 458 }
 459 
 460 /*
 461  * Return an index from a linear array which stores the auxiliar binary
 462  * tree, j is the cacheline index of t->data.
 463  */
 464 static unsigned int inorder_to_tree(unsigned int j, struct bset_tree *t)
 465 {
 466         return __inorder_to_tree(j, t->size, t->extra);
 467 }
 468 
 469 #if 0
 470 void inorder_test(void)
 471 {
 472         unsigned long done = 0;
 473         ktime_t start = ktime_get();
 474 
 475         for (unsigned int size = 2;
 476              size < 65536000;
 477              size++) {
 478                 unsigned int extra =
 479                         (size - rounddown_pow_of_two(size - 1)) << 1;
 480                 unsigned int i = 1, j = rounddown_pow_of_two(size - 1);
 481 
 482                 if (!(size % 4096))
 483                         pr_notice("loop %u, %llu per us\n", size,
 484                                done / ktime_us_delta(ktime_get(), start));
 485 
 486                 while (1) {
 487                         if (__inorder_to_tree(i, size, extra) != j)
 488                                 panic("size %10u j %10u i %10u", size, j, i);
 489 
 490                         if (__to_inorder(j, size, extra) != i)
 491                                 panic("size %10u j %10u i %10u", size, j, i);
 492 
 493                         if (j == rounddown_pow_of_two(size) - 1)
 494                                 break;
 495 
 496                         BUG_ON(inorder_prev(inorder_next(j, size), size) != j);
 497 
 498                         j = inorder_next(j, size);
 499                         i++;
 500                 }
 501 
 502                 done += size - 1;
 503         }
 504 }
 505 #endif
 506 
 507 /*
 508  * Cacheline/offset <-> bkey pointer arithmetic:
 509  *
 510  * t->tree is a binary search tree in an array; each node corresponds to a key
 511  * in one cacheline in t->set (BSET_CACHELINE bytes).
 512  *
 513  * This means we don't have to store the full index of the key that a node in
 514  * the binary tree points to; to_inorder() gives us the cacheline, and then
 515  * bkey_float->m gives us the offset within that cacheline, in units of 8 bytes.
 516  *
 517  * cacheline_to_bkey() and friends abstract out all the pointer arithmetic to
 518  * make this work.
 519  *
 520  * To construct the bfloat for an arbitrary key we need to know what the key
 521  * immediately preceding it is: we have to check if the two keys differ in the
 522  * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size
 523  * of the previous key so we can walk backwards to it from t->tree[j]'s key.
 524  */
 525 
 526 static struct bkey *cacheline_to_bkey(struct bset_tree *t,
 527                                       unsigned int cacheline,
 528                                       unsigned int offset)
 529 {
 530         return ((void *) t->data) + cacheline * BSET_CACHELINE + offset * 8;
 531 }
 532 
 533 static unsigned int bkey_to_cacheline(struct bset_tree *t, struct bkey *k)
 534 {
 535         return ((void *) k - (void *) t->data) / BSET_CACHELINE;
 536 }
 537 
 538 static unsigned int bkey_to_cacheline_offset(struct bset_tree *t,
 539                                          unsigned int cacheline,
 540                                          struct bkey *k)
 541 {
 542         return (u64 *) k - (u64 *) cacheline_to_bkey(t, cacheline, 0);
 543 }
 544 
 545 static struct bkey *tree_to_bkey(struct bset_tree *t, unsigned int j)
 546 {
 547         return cacheline_to_bkey(t, to_inorder(j, t), t->tree[j].m);
 548 }
 549 
 550 static struct bkey *tree_to_prev_bkey(struct bset_tree *t, unsigned int j)
 551 {
 552         return (void *) (((uint64_t *) tree_to_bkey(t, j)) - t->prev[j]);
 553 }
 554 
 555 /*
 556  * For the write set - the one we're currently inserting keys into - we don't
 557  * maintain a full search tree, we just keep a simple lookup table in t->prev.
 558  */
 559 static struct bkey *table_to_bkey(struct bset_tree *t, unsigned int cacheline)
 560 {
 561         return cacheline_to_bkey(t, cacheline, t->prev[cacheline]);
 562 }
 563 
 564 static inline uint64_t shrd128(uint64_t high, uint64_t low, uint8_t shift)
 565 {
 566         low >>= shift;
 567         low  |= (high << 1) << (63U - shift);
 568         return low;
 569 }
 570 
 571 /*
 572  * Calculate mantissa value for struct bkey_float.
 573  * If most significant bit of f->exponent is not set, then
 574  *  - f->exponent >> 6 is 0
 575  *  - p[0] points to bkey->low
 576  *  - p[-1] borrows bits from KEY_INODE() of bkey->high
 577  * if most isgnificant bits of f->exponent is set, then
 578  *  - f->exponent >> 6 is 1
 579  *  - p[0] points to bits from KEY_INODE() of bkey->high
 580  *  - p[-1] points to other bits from KEY_INODE() of
 581  *    bkey->high too.
 582  * See make_bfloat() to check when most significant bit of f->exponent
 583  * is set or not.
 584  */
 585 static inline unsigned int bfloat_mantissa(const struct bkey *k,
 586                                        struct bkey_float *f)
 587 {
 588         const uint64_t *p = &k->low - (f->exponent >> 6);
 589 
 590         return shrd128(p[-1], p[0], f->exponent & 63) & BKEY_MANTISSA_MASK;
 591 }
 592 
 593 static void make_bfloat(struct bset_tree *t, unsigned int j)
 594 {
 595         struct bkey_float *f = &t->tree[j];
 596         struct bkey *m = tree_to_bkey(t, j);
 597         struct bkey *p = tree_to_prev_bkey(t, j);
 598 
 599         struct bkey *l = is_power_of_2(j)
 600                 ? t->data->start
 601                 : tree_to_prev_bkey(t, j >> ffs(j));
 602 
 603         struct bkey *r = is_power_of_2(j + 1)
 604                 ? bset_bkey_idx(t->data, t->data->keys - bkey_u64s(&t->end))
 605                 : tree_to_bkey(t, j >> (ffz(j) + 1));
 606 
 607         BUG_ON(m < l || m > r);
 608         BUG_ON(bkey_next(p) != m);
 609 
 610         /*
 611          * If l and r have different KEY_INODE values (different backing
 612          * device), f->exponent records how many least significant bits
 613          * are different in KEY_INODE values and sets most significant
 614          * bits to 1 (by +64).
 615          * If l and r have same KEY_INODE value, f->exponent records
 616          * how many different bits in least significant bits of bkey->low.
 617          * See bfloat_mantiss() how the most significant bit of
 618          * f->exponent is used to calculate bfloat mantissa value.
 619          */
 620         if (KEY_INODE(l) != KEY_INODE(r))
 621                 f->exponent = fls64(KEY_INODE(r) ^ KEY_INODE(l)) + 64;
 622         else
 623                 f->exponent = fls64(r->low ^ l->low);
 624 
 625         f->exponent = max_t(int, f->exponent - BKEY_MANTISSA_BITS, 0);
 626 
 627         /*
 628          * Setting f->exponent = 127 flags this node as failed, and causes the
 629          * lookup code to fall back to comparing against the original key.
 630          */
 631 
 632         if (bfloat_mantissa(m, f) != bfloat_mantissa(p, f))
 633                 f->mantissa = bfloat_mantissa(m, f) - 1;
 634         else
 635                 f->exponent = 127;
 636 }
 637 
 638 static void bset_alloc_tree(struct btree_keys *b, struct bset_tree *t)
 639 {
 640         if (t != b->set) {
 641                 unsigned int j = roundup(t[-1].size,
 642                                      64 / sizeof(struct bkey_float));
 643 
 644                 t->tree = t[-1].tree + j;
 645                 t->prev = t[-1].prev + j;
 646         }
 647 
 648         while (t < b->set + MAX_BSETS)
 649                 t++->size = 0;
 650 }
 651 
 652 static void bch_bset_build_unwritten_tree(struct btree_keys *b)
 653 {
 654         struct bset_tree *t = bset_tree_last(b);
 655 
 656         BUG_ON(b->last_set_unwritten);
 657         b->last_set_unwritten = 1;
 658 
 659         bset_alloc_tree(b, t);
 660 
 661         if (t->tree != b->set->tree + btree_keys_cachelines(b)) {
 662                 t->prev[0] = bkey_to_cacheline_offset(t, 0, t->data->start);
 663                 t->size = 1;
 664         }
 665 }
 666 
 667 void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
 668 {
 669         if (i != b->set->data) {
 670                 b->set[++b->nsets].data = i;
 671                 i->seq = b->set->data->seq;
 672         } else
 673                 get_random_bytes(&i->seq, sizeof(uint64_t));
 674 
 675         i->magic        = magic;
 676         i->version      = 0;
 677         i->keys         = 0;
 678 
 679         bch_bset_build_unwritten_tree(b);
 680 }
 681 EXPORT_SYMBOL(bch_bset_init_next);
 682 
 683 /*
 684  * Build auxiliary binary tree 'struct bset_tree *t', this tree is used to
 685  * accelerate bkey search in a btree node (pointed by bset_tree->data in
 686  * memory). After search in the auxiliar tree by calling bset_search_tree(),
 687  * a struct bset_search_iter is returned which indicates range [l, r] from
 688  * bset_tree->data where the searching bkey might be inside. Then a followed
 689  * linear comparison does the exact search, see __bch_bset_search() for how
 690  * the auxiliary tree is used.
 691  */
 692 void bch_bset_build_written_tree(struct btree_keys *b)
 693 {
 694         struct bset_tree *t = bset_tree_last(b);
 695         struct bkey *prev = NULL, *k = t->data->start;
 696         unsigned int j, cacheline = 1;
 697 
 698         b->last_set_unwritten = 0;
 699 
 700         bset_alloc_tree(b, t);
 701 
 702         t->size = min_t(unsigned int,
 703                         bkey_to_cacheline(t, bset_bkey_last(t->data)),
 704                         b->set->tree + btree_keys_cachelines(b) - t->tree);
 705 
 706         if (t->size < 2) {
 707                 t->size = 0;
 708                 return;
 709         }
 710 
 711         t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1;
 712 
 713         /* First we figure out where the first key in each cacheline is */
 714         for (j = inorder_next(0, t->size);
 715              j;
 716              j = inorder_next(j, t->size)) {
 717                 while (bkey_to_cacheline(t, k) < cacheline)
 718                         prev = k, k = bkey_next(k);
 719 
 720                 t->prev[j] = bkey_u64s(prev);
 721                 t->tree[j].m = bkey_to_cacheline_offset(t, cacheline++, k);
 722         }
 723 
 724         while (bkey_next(k) != bset_bkey_last(t->data))
 725                 k = bkey_next(k);
 726 
 727         t->end = *k;
 728 
 729         /* Then we build the tree */
 730         for (j = inorder_next(0, t->size);
 731              j;
 732              j = inorder_next(j, t->size))
 733                 make_bfloat(t, j);
 734 }
 735 EXPORT_SYMBOL(bch_bset_build_written_tree);
 736 
 737 /* Insert */
 738 
 739 void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k)
 740 {
 741         struct bset_tree *t;
 742         unsigned int inorder, j = 1;
 743 
 744         for (t = b->set; t <= bset_tree_last(b); t++)
 745                 if (k < bset_bkey_last(t->data))
 746                         goto found_set;
 747 
 748         BUG();
 749 found_set:
 750         if (!t->size || !bset_written(b, t))
 751                 return;
 752 
 753         inorder = bkey_to_cacheline(t, k);
 754 
 755         if (k == t->data->start)
 756                 goto fix_left;
 757 
 758         if (bkey_next(k) == bset_bkey_last(t->data)) {
 759                 t->end = *k;
 760                 goto fix_right;
 761         }
 762 
 763         j = inorder_to_tree(inorder, t);
 764 
 765         if (j &&
 766             j < t->size &&
 767             k == tree_to_bkey(t, j))
 768 fix_left:       do {
 769                         make_bfloat(t, j);
 770                         j = j * 2;
 771                 } while (j < t->size);
 772 
 773         j = inorder_to_tree(inorder + 1, t);
 774 
 775         if (j &&
 776             j < t->size &&
 777             k == tree_to_prev_bkey(t, j))
 778 fix_right:      do {
 779                         make_bfloat(t, j);
 780                         j = j * 2 + 1;
 781                 } while (j < t->size);
 782 }
 783 EXPORT_SYMBOL(bch_bset_fix_invalidated_key);
 784 
 785 static void bch_bset_fix_lookup_table(struct btree_keys *b,
 786                                       struct bset_tree *t,
 787                                       struct bkey *k)
 788 {
 789         unsigned int shift = bkey_u64s(k);
 790         unsigned int j = bkey_to_cacheline(t, k);
 791 
 792         /* We're getting called from btree_split() or btree_gc, just bail out */
 793         if (!t->size)
 794                 return;
 795 
 796         /*
 797          * k is the key we just inserted; we need to find the entry in the
 798          * lookup table for the first key that is strictly greater than k:
 799          * it's either k's cacheline or the next one
 800          */
 801         while (j < t->size &&
 802                table_to_bkey(t, j) <= k)
 803                 j++;
 804 
 805         /*
 806          * Adjust all the lookup table entries, and find a new key for any that
 807          * have gotten too big
 808          */
 809         for (; j < t->size; j++) {
 810                 t->prev[j] += shift;
 811 
 812                 if (t->prev[j] > 7) {
 813                         k = table_to_bkey(t, j - 1);
 814 
 815                         while (k < cacheline_to_bkey(t, j, 0))
 816                                 k = bkey_next(k);
 817 
 818                         t->prev[j] = bkey_to_cacheline_offset(t, j, k);
 819                 }
 820         }
 821 
 822         if (t->size == b->set->tree + btree_keys_cachelines(b) - t->tree)
 823                 return;
 824 
 825         /* Possibly add a new entry to the end of the lookup table */
 826 
 827         for (k = table_to_bkey(t, t->size - 1);
 828              k != bset_bkey_last(t->data);
 829              k = bkey_next(k))
 830                 if (t->size == bkey_to_cacheline(t, k)) {
 831                         t->prev[t->size] =
 832                                 bkey_to_cacheline_offset(t, t->size, k);
 833                         t->size++;
 834                 }
 835 }
 836 
 837 /*
 838  * Tries to merge l and r: l should be lower than r
 839  * Returns true if we were able to merge. If we did merge, l will be the merged
 840  * key, r will be untouched.
 841  */
 842 bool bch_bkey_try_merge(struct btree_keys *b, struct bkey *l, struct bkey *r)
 843 {
 844         if (!b->ops->key_merge)
 845                 return false;
 846 
 847         /*
 848          * Generic header checks
 849          * Assumes left and right are in order
 850          * Left and right must be exactly aligned
 851          */
 852         if (!bch_bkey_equal_header(l, r) ||
 853              bkey_cmp(l, &START_KEY(r)))
 854                 return false;
 855 
 856         return b->ops->key_merge(b, l, r);
 857 }
 858 EXPORT_SYMBOL(bch_bkey_try_merge);
 859 
 860 void bch_bset_insert(struct btree_keys *b, struct bkey *where,
 861                      struct bkey *insert)
 862 {
 863         struct bset_tree *t = bset_tree_last(b);
 864 
 865         BUG_ON(!b->last_set_unwritten);
 866         BUG_ON(bset_byte_offset(b, t->data) +
 867                __set_bytes(t->data, t->data->keys + bkey_u64s(insert)) >
 868                PAGE_SIZE << b->page_order);
 869 
 870         memmove((uint64_t *) where + bkey_u64s(insert),
 871                 where,
 872                 (void *) bset_bkey_last(t->data) - (void *) where);
 873 
 874         t->data->keys += bkey_u64s(insert);
 875         bkey_copy(where, insert);
 876         bch_bset_fix_lookup_table(b, t, where);
 877 }
 878 EXPORT_SYMBOL(bch_bset_insert);
 879 
 880 unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
 881                               struct bkey *replace_key)
 882 {
 883         unsigned int status = BTREE_INSERT_STATUS_NO_INSERT;
 884         struct bset *i = bset_tree_last(b)->data;
 885         struct bkey *m, *prev = NULL;
 886         struct btree_iter iter;
 887         struct bkey preceding_key_on_stack = ZERO_KEY;
 888         struct bkey *preceding_key_p = &preceding_key_on_stack;
 889 
 890         BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
 891 
 892         /*
 893          * If k has preceding key, preceding_key_p will be set to address
 894          *  of k's preceding key; otherwise preceding_key_p will be set
 895          * to NULL inside preceding_key().
 896          */
 897         if (b->ops->is_extents)
 898                 preceding_key(&START_KEY(k), &preceding_key_p);
 899         else
 900                 preceding_key(k, &preceding_key_p);
 901 
 902         m = bch_btree_iter_init(b, &iter, preceding_key_p);
 903 
 904         if (b->ops->insert_fixup(b, k, &iter, replace_key))
 905                 return status;
 906 
 907         status = BTREE_INSERT_STATUS_INSERT;
 908 
 909         while (m != bset_bkey_last(i) &&
 910                bkey_cmp(k, b->ops->is_extents ? &START_KEY(m) : m) > 0)
 911                 prev = m, m = bkey_next(m);
 912 
 913         /* prev is in the tree, if we merge we're done */
 914         status = BTREE_INSERT_STATUS_BACK_MERGE;
 915         if (prev &&
 916             bch_bkey_try_merge(b, prev, k))
 917                 goto merged;
 918 #if 0
 919         status = BTREE_INSERT_STATUS_OVERWROTE;
 920         if (m != bset_bkey_last(i) &&
 921             KEY_PTRS(m) == KEY_PTRS(k) && !KEY_SIZE(m))
 922                 goto copy;
 923 #endif
 924         status = BTREE_INSERT_STATUS_FRONT_MERGE;
 925         if (m != bset_bkey_last(i) &&
 926             bch_bkey_try_merge(b, k, m))
 927                 goto copy;
 928 
 929         bch_bset_insert(b, m, k);
 930 copy:   bkey_copy(m, k);
 931 merged:
 932         return status;
 933 }
 934 EXPORT_SYMBOL(bch_btree_insert_key);
 935 
 936 /* Lookup */
 937 
 938 struct bset_search_iter {
 939         struct bkey *l, *r;
 940 };
 941 
 942 static struct bset_search_iter bset_search_write_set(struct bset_tree *t,
 943                                                      const struct bkey *search)
 944 {
 945         unsigned int li = 0, ri = t->size;
 946 
 947         while (li + 1 != ri) {
 948                 unsigned int m = (li + ri) >> 1;
 949 
 950                 if (bkey_cmp(table_to_bkey(t, m), search) > 0)
 951                         ri = m;
 952                 else
 953                         li = m;
 954         }
 955 
 956         return (struct bset_search_iter) {
 957                 table_to_bkey(t, li),
 958                 ri < t->size ? table_to_bkey(t, ri) : bset_bkey_last(t->data)
 959         };
 960 }
 961 
 962 static struct bset_search_iter bset_search_tree(struct bset_tree *t,
 963                                                 const struct bkey *search)
 964 {
 965         struct bkey *l, *r;
 966         struct bkey_float *f;
 967         unsigned int inorder, j, n = 1;
 968 
 969         do {
 970                 unsigned int p = n << 4;
 971 
 972                 if (p < t->size)
 973                         prefetch(&t->tree[p]);
 974 
 975                 j = n;
 976                 f = &t->tree[j];
 977 
 978                 if (likely(f->exponent != 127)) {
 979                         if (f->mantissa >= bfloat_mantissa(search, f))
 980                                 n = j * 2;
 981                         else
 982                                 n = j * 2 + 1;
 983                 } else {
 984                         if (bkey_cmp(tree_to_bkey(t, j), search) > 0)
 985                                 n = j * 2;
 986                         else
 987                                 n = j * 2 + 1;
 988                 }
 989         } while (n < t->size);
 990 
 991         inorder = to_inorder(j, t);
 992 
 993         /*
 994          * n would have been the node we recursed to - the low bit tells us if
 995          * we recursed left or recursed right.
 996          */
 997         if (n & 1) {
 998                 l = cacheline_to_bkey(t, inorder, f->m);
 999 
1000                 if (++inorder != t->size) {
1001                         f = &t->tree[inorder_next(j, t->size)];
1002                         r = cacheline_to_bkey(t, inorder, f->m);
1003                 } else
1004                         r = bset_bkey_last(t->data);
1005         } else {
1006                 r = cacheline_to_bkey(t, inorder, f->m);
1007 
1008                 if (--inorder) {
1009                         f = &t->tree[inorder_prev(j, t->size)];
1010                         l = cacheline_to_bkey(t, inorder, f->m);
1011                 } else
1012                         l = t->data->start;
1013         }
1014 
1015         return (struct bset_search_iter) {l, r};
1016 }
1017 
1018 struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
1019                                const struct bkey *search)
1020 {
1021         struct bset_search_iter i;
1022 
1023         /*
1024          * First, we search for a cacheline, then lastly we do a linear search
1025          * within that cacheline.
1026          *
1027          * To search for the cacheline, there's three different possibilities:
1028          *  * The set is too small to have a search tree, so we just do a linear
1029          *    search over the whole set.
1030          *  * The set is the one we're currently inserting into; keeping a full
1031          *    auxiliary search tree up to date would be too expensive, so we
1032          *    use a much simpler lookup table to do a binary search -
1033          *    bset_search_write_set().
1034          *  * Or we use the auxiliary search tree we constructed earlier -
1035          *    bset_search_tree()
1036          */
1037 
1038         if (unlikely(!t->size)) {
1039                 i.l = t->data->start;
1040                 i.r = bset_bkey_last(t->data);
1041         } else if (bset_written(b, t)) {
1042                 /*
1043                  * Each node in the auxiliary search tree covers a certain range
1044                  * of bits, and keys above and below the set it covers might
1045                  * differ outside those bits - so we have to special case the
1046                  * start and end - handle that here:
1047                  */
1048 
1049                 if (unlikely(bkey_cmp(search, &t->end) >= 0))
1050                         return bset_bkey_last(t->data);
1051 
1052                 if (unlikely(bkey_cmp(search, t->data->start) < 0))
1053                         return t->data->start;
1054 
1055                 i = bset_search_tree(t, search);
1056         } else {
1057                 BUG_ON(!b->nsets &&
1058                        t->size < bkey_to_cacheline(t, bset_bkey_last(t->data)));
1059 
1060                 i = bset_search_write_set(t, search);
1061         }
1062 
1063         if (btree_keys_expensive_checks(b)) {
1064                 BUG_ON(bset_written(b, t) &&
1065                        i.l != t->data->start &&
1066                        bkey_cmp(tree_to_prev_bkey(t,
1067                           inorder_to_tree(bkey_to_cacheline(t, i.l), t)),
1068                                 search) > 0);
1069 
1070                 BUG_ON(i.r != bset_bkey_last(t->data) &&
1071                        bkey_cmp(i.r, search) <= 0);
1072         }
1073 
1074         while (likely(i.l != i.r) &&
1075                bkey_cmp(i.l, search) <= 0)
1076                 i.l = bkey_next(i.l);
1077 
1078         return i.l;
1079 }
1080 EXPORT_SYMBOL(__bch_bset_search);
1081 
1082 /* Btree iterator */
1083 
1084 typedef bool (btree_iter_cmp_fn)(struct btree_iter_set,
1085                                  struct btree_iter_set);
1086 
1087 static inline bool btree_iter_cmp(struct btree_iter_set l,
1088                                   struct btree_iter_set r)
1089 {
1090         return bkey_cmp(l.k, r.k) > 0;
1091 }
1092 
1093 static inline bool btree_iter_end(struct btree_iter *iter)
1094 {
1095         return !iter->used;
1096 }
1097 
1098 void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
1099                          struct bkey *end)
1100 {
1101         if (k != end)
1102                 BUG_ON(!heap_add(iter,
1103                                  ((struct btree_iter_set) { k, end }),
1104                                  btree_iter_cmp));
1105 }
1106 
1107 static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
1108                                           struct btree_iter *iter,
1109                                           struct bkey *search,
1110                                           struct bset_tree *start)
1111 {
1112         struct bkey *ret = NULL;
1113 
1114         iter->size = ARRAY_SIZE(iter->data);
1115         iter->used = 0;
1116 
1117 #ifdef CONFIG_BCACHE_DEBUG
1118         iter->b = b;
1119 #endif
1120 
1121         for (; start <= bset_tree_last(b); start++) {
1122                 ret = bch_bset_search(b, start, search);
1123                 bch_btree_iter_push(iter, ret, bset_bkey_last(start->data));
1124         }
1125 
1126         return ret;
1127 }
1128 
1129 struct bkey *bch_btree_iter_init(struct btree_keys *b,
1130                                  struct btree_iter *iter,
1131                                  struct bkey *search)
1132 {
1133         return __bch_btree_iter_init(b, iter, search, b->set);
1134 }
1135 EXPORT_SYMBOL(bch_btree_iter_init);
1136 
1137 static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
1138                                                  btree_iter_cmp_fn *cmp)
1139 {
1140         struct btree_iter_set b __maybe_unused;
1141         struct bkey *ret = NULL;
1142 
1143         if (!btree_iter_end(iter)) {
1144                 bch_btree_iter_next_check(iter);
1145 
1146                 ret = iter->data->k;
1147                 iter->data->k = bkey_next(iter->data->k);
1148 
1149                 if (iter->data->k > iter->data->end) {
1150                         WARN_ONCE(1, "bset was corrupt!\n");
1151                         iter->data->k = iter->data->end;
1152                 }
1153 
1154                 if (iter->data->k == iter->data->end)
1155                         heap_pop(iter, b, cmp);
1156                 else
1157                         heap_sift(iter, 0, cmp);
1158         }
1159 
1160         return ret;
1161 }
1162 
1163 struct bkey *bch_btree_iter_next(struct btree_iter *iter)
1164 {
1165         return __bch_btree_iter_next(iter, btree_iter_cmp);
1166 
1167 }
1168 EXPORT_SYMBOL(bch_btree_iter_next);
1169 
1170 struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,
1171                                         struct btree_keys *b, ptr_filter_fn fn)
1172 {
1173         struct bkey *ret;
1174 
1175         do {
1176                 ret = bch_btree_iter_next(iter);
1177         } while (ret && fn(b, ret));
1178 
1179         return ret;
1180 }
1181 
1182 /* Mergesort */
1183 
1184 void bch_bset_sort_state_free(struct bset_sort_state *state)
1185 {
1186         mempool_exit(&state->pool);
1187 }
1188 
1189 int bch_bset_sort_state_init(struct bset_sort_state *state,
1190                              unsigned int page_order)
1191 {
1192         spin_lock_init(&state->time.lock);
1193 
1194         state->page_order = page_order;
1195         state->crit_factor = int_sqrt(1 << page_order);
1196 
1197         return mempool_init_page_pool(&state->pool, 1, page_order);
1198 }
1199 EXPORT_SYMBOL(bch_bset_sort_state_init);
1200 
1201 static void btree_mergesort(struct btree_keys *b, struct bset *out,
1202                             struct btree_iter *iter,
1203                             bool fixup, bool remove_stale)
1204 {
1205         int i;
1206         struct bkey *k, *last = NULL;
1207         BKEY_PADDED(k) tmp;
1208         bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale
1209                 ? bch_ptr_bad
1210                 : bch_ptr_invalid;
1211 
1212         /* Heapify the iterator, using our comparison function */
1213         for (i = iter->used / 2 - 1; i >= 0; --i)
1214                 heap_sift(iter, i, b->ops->sort_cmp);
1215 
1216         while (!btree_iter_end(iter)) {
1217                 if (b->ops->sort_fixup && fixup)
1218                         k = b->ops->sort_fixup(iter, &tmp.k);
1219                 else
1220                         k = NULL;
1221 
1222                 if (!k)
1223                         k = __bch_btree_iter_next(iter, b->ops->sort_cmp);
1224 
1225                 if (bad(b, k))
1226                         continue;
1227 
1228                 if (!last) {
1229                         last = out->start;
1230                         bkey_copy(last, k);
1231                 } else if (!bch_bkey_try_merge(b, last, k)) {
1232                         last = bkey_next(last);
1233                         bkey_copy(last, k);
1234                 }
1235         }
1236 
1237         out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0;
1238 
1239         pr_debug("sorted %i keys", out->keys);
1240 }
1241 
1242 static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
1243                          unsigned int start, unsigned int order, bool fixup,
1244                          struct bset_sort_state *state)
1245 {
1246         uint64_t start_time;
1247         bool used_mempool = false;
1248         struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOWAIT,
1249                                                      order);
1250         if (!out) {
1251                 struct page *outp;
1252 
1253                 BUG_ON(order > state->page_order);
1254 
1255                 outp = mempool_alloc(&state->pool, GFP_NOIO);
1256                 out = page_address(outp);
1257                 used_mempool = true;
1258                 order = state->page_order;
1259         }
1260 
1261         start_time = local_clock();
1262 
1263         btree_mergesort(b, out, iter, fixup, false);
1264         b->nsets = start;
1265 
1266         if (!start && order == b->page_order) {
1267                 /*
1268                  * Our temporary buffer is the same size as the btree node's
1269                  * buffer, we can just swap buffers instead of doing a big
1270                  * memcpy()
1271                  */
1272 
1273                 out->magic      = b->set->data->magic;
1274                 out->seq        = b->set->data->seq;
1275                 out->version    = b->set->data->version;
1276                 swap(out, b->set->data);
1277         } else {
1278                 b->set[start].data->keys = out->keys;
1279                 memcpy(b->set[start].data->start, out->start,
1280                        (void *) bset_bkey_last(out) - (void *) out->start);
1281         }
1282 
1283         if (used_mempool)
1284                 mempool_free(virt_to_page(out), &state->pool);
1285         else
1286                 free_pages((unsigned long) out, order);
1287 
1288         bch_bset_build_written_tree(b);
1289 
1290         if (!start)
1291                 bch_time_stats_update(&state->time, start_time);
1292 }
1293 
1294 void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
1295                             struct bset_sort_state *state)
1296 {
1297         size_t order = b->page_order, keys = 0;
1298         struct btree_iter iter;
1299         int oldsize = bch_count_data(b);
1300 
1301         __bch_btree_iter_init(b, &iter, NULL, &b->set[start]);
1302 
1303         if (start) {
1304                 unsigned int i;
1305 
1306                 for (i = start; i <= b->nsets; i++)
1307                         keys += b->set[i].data->keys;
1308 
1309                 order = get_order(__set_bytes(b->set->data, keys));
1310         }
1311 
1312         __btree_sort(b, &iter, start, order, false, state);
1313 
1314         EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize);
1315 }
1316 EXPORT_SYMBOL(bch_btree_sort_partial);
1317 
1318 void bch_btree_sort_and_fix_extents(struct btree_keys *b,
1319                                     struct btree_iter *iter,
1320                                     struct bset_sort_state *state)
1321 {
1322         __btree_sort(b, iter, 0, b->page_order, true, state);
1323 }
1324 
1325 void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new,
1326                          struct bset_sort_state *state)
1327 {
1328         uint64_t start_time = local_clock();
1329         struct btree_iter iter;
1330 
1331         bch_btree_iter_init(b, &iter, NULL);
1332 
1333         btree_mergesort(b, new->set->data, &iter, false, true);
1334 
1335         bch_time_stats_update(&state->time, start_time);
1336 
1337         new->set->size = 0; // XXX: why?
1338 }
1339 
1340 #define SORT_CRIT       (4096 / sizeof(uint64_t))
1341 
1342 void bch_btree_sort_lazy(struct btree_keys *b, struct bset_sort_state *state)
1343 {
1344         unsigned int crit = SORT_CRIT;
1345         int i;
1346 
1347         /* Don't sort if nothing to do */
1348         if (!b->nsets)
1349                 goto out;
1350 
1351         for (i = b->nsets - 1; i >= 0; --i) {
1352                 crit *= state->crit_factor;
1353 
1354                 if (b->set[i].data->keys < crit) {
1355                         bch_btree_sort_partial(b, i, state);
1356                         return;
1357                 }
1358         }
1359 
1360         /* Sort if we'd overflow */
1361         if (b->nsets + 1 == MAX_BSETS) {
1362                 bch_btree_sort(b, state);
1363                 return;
1364         }
1365 
1366 out:
1367         bch_bset_build_written_tree(b);
1368 }
1369 EXPORT_SYMBOL(bch_btree_sort_lazy);
1370 
1371 void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats)
1372 {
1373         unsigned int i;
1374 
1375         for (i = 0; i <= b->nsets; i++) {
1376                 struct bset_tree *t = &b->set[i];
1377                 size_t bytes = t->data->keys * sizeof(uint64_t);
1378                 size_t j;
1379 
1380                 if (bset_written(b, t)) {
1381                         stats->sets_written++;
1382                         stats->bytes_written += bytes;
1383 
1384                         stats->floats += t->size - 1;
1385 
1386                         for (j = 1; j < t->size; j++)
1387                                 if (t->tree[j].exponent == 127)
1388                                         stats->failed++;
1389                 } else {
1390                         stats->sets_unwritten++;
1391                         stats->bytes_unwritten += bytes;
1392                 }
1393         }
1394 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/md/bcache/bset.c

DEFINITIONS
