git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/bset.c

   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 #include "bcachefs.h"
  10 #include "btree_cache.h"
  11 #include "bset.h"
  12 #include "eytzinger.h"
  13 #include "util.h"
  14
  15 #include <asm/unaligned.h>
  16 #include <linux/console.h>
  17 #include <linux/random.h>
  18 #include <linux/prefetch.h>
  19
  20 /* hack.. */
  21 #include "alloc_types.h"
  22 #include <trace/events/bcachefs.h>
  23
  24 static inline void __bch2_btree_node_iter_advance(struct btree_node_iter *,
  25                                                   struct btree *);
  26
  27 static inline unsigned __btree_node_iter_used(struct btree_node_iter *iter)
  28 {
  29         unsigned n = ARRAY_SIZE(iter->data);
  30
  31         while (n && __btree_node_iter_set_end(iter, n - 1))
  32                 --n;
  33
  34         return n;
  35 }
  36
  37 struct bset_tree *bch2_bkey_to_bset(struct btree *b, struct bkey_packed *k)
  38 {
  39         unsigned offset = __btree_node_key_to_offset(b, k);
  40         struct bset_tree *t;
  41
  42         for_each_bset(b, t)
  43                 if (offset <= t->end_offset) {
  44                         EBUG_ON(offset < btree_bkey_first_offset(t));
  45                         return t;
  46                 }
  47
  48         BUG();
  49 }
  50
  51 /*
  52  * There are never duplicate live keys in the btree - but including keys that
  53  * have been flagged as deleted (and will be cleaned up later) we _will_ see
  54  * duplicates.
  55  *
  56  * Thus the sort order is: usual key comparison first, but for keys that compare
  57  * equal the deleted key(s) come first, and the (at most one) live version comes
  58  * last.
  59  *
  60  * The main reason for this is insertion: to handle overwrites, we first iterate
  61  * over keys that compare equal to our insert key, and then insert immediately
  62  * prior to the first key greater than the key we're inserting - our insert
  63  * position will be after all keys that compare equal to our insert key, which
  64  * by the time we actually do the insert will all be deleted.
  65  */
  66
  67 void bch2_dump_bset(struct bch_fs *c, struct btree *b,
  68                     struct bset *i, unsigned set)
  69 {
  70         struct bkey_packed *_k, *_n;
  71         struct bkey uk, n;
  72         struct bkey_s_c k;
  73         char buf[200];
  74
  75         if (!i->u64s)
  76                 return;
  77
  78         for (_k = i->start;
  79              _k < vstruct_last(i);
  80              _k = _n) {
  81                 _n = bkey_next_skip_noops(_k, vstruct_last(i));
  82
  83                 k = bkey_disassemble(b, _k, &uk);
  84                 if (c)
  85                         bch2_bkey_val_to_text(&PBUF(buf), c, k);
  86                 else
  87                         bch2_bkey_to_text(&PBUF(buf), k.k);
  88                 printk(KERN_ERR "block %u key %5zu: %s\n", set,
  89                        _k->_data - i->_data, buf);
  90
  91                 if (_n == vstruct_last(i))
  92                         continue;
  93
  94                 n = bkey_unpack_key(b, _n);
  95
  96                 if (bkey_cmp(bkey_start_pos(&n), k.k->p) < 0) {
  97                         printk(KERN_ERR "Key skipped backwards\n");
  98                         continue;
  99                 }
 100
 101                 if (!bkey_deleted(k.k) &&
 102                     !bkey_cmp(n.p, k.k->p))
 103                         printk(KERN_ERR "Duplicate keys\n");
 104         }
 105 }
 106
 107 void bch2_dump_btree_node(struct bch_fs *c, struct btree *b)
 108 {
 109         struct bset_tree *t;
 110
 111         console_lock();
 112         for_each_bset(b, t)
 113                 bch2_dump_bset(c, b, bset(b, t), t - b->set);
 114         console_unlock();
 115 }
 116
 117 void bch2_dump_btree_node_iter(struct btree *b,
 118                               struct btree_node_iter *iter)
 119 {
 120         struct btree_node_iter_set *set;
 121
 122         printk(KERN_ERR "btree node iter with %u/%u sets:\n",
 123                __btree_node_iter_used(iter), b->nsets);
 124
 125         btree_node_iter_for_each(iter, set) {
 126                 struct bkey_packed *k = __btree_node_offset_to_key(b, set->k);
 127                 struct bset_tree *t = bch2_bkey_to_bset(b, k);
 128                 struct bkey uk = bkey_unpack_key(b, k);
 129                 char buf[100];
 130
 131                 bch2_bkey_to_text(&PBUF(buf), &uk);
 132                 printk(KERN_ERR "set %zu key %u: %s\n",
 133                        t - b->set, set->k, buf);
 134         }
 135 }
 136
 137 #ifdef CONFIG_BCACHEFS_DEBUG
 138
 139 void __bch2_verify_btree_nr_keys(struct btree *b)
 140 {
 141         struct bset_tree *t;
 142         struct bkey_packed *k;
 143         struct btree_nr_keys nr = { 0 };
 144
 145         for_each_bset(b, t)
 146                 bset_tree_for_each_key(b, t, k)
 147                         if (!bkey_whiteout(k))
 148                                 btree_keys_account_key_add(&nr, t - b->set, k);
 149
 150         BUG_ON(memcmp(&nr, &b->nr, sizeof(nr)));
 151 }
 152
 153 static void bch2_btree_node_iter_next_check(struct btree_node_iter *_iter,
 154                                             struct btree *b)
 155 {
 156         struct btree_node_iter iter = *_iter;
 157         const struct bkey_packed *k, *n;
 158
 159         k = bch2_btree_node_iter_peek_all(&iter, b);
 160         __bch2_btree_node_iter_advance(&iter, b);
 161         n = bch2_btree_node_iter_peek_all(&iter, b);
 162
 163         bkey_unpack_key(b, k);
 164
 165         if (n &&
 166             bkey_iter_cmp(b, k, n) > 0) {
 167                 struct btree_node_iter_set *set;
 168                 struct bkey ku = bkey_unpack_key(b, k);
 169                 struct bkey nu = bkey_unpack_key(b, n);
 170                 char buf1[80], buf2[80];
 171
 172                 bch2_dump_btree_node(NULL, b);
 173                 bch2_bkey_to_text(&PBUF(buf1), &ku);
 174                 bch2_bkey_to_text(&PBUF(buf2), &nu);
 175                 printk(KERN_ERR "out of order/overlapping:\n%s\n%s\n",
 176                        buf1, buf2);
 177                 printk(KERN_ERR "iter was:");
 178
 179                 btree_node_iter_for_each(_iter, set) {
 180                         struct bkey_packed *k = __btree_node_offset_to_key(b, set->k);
 181                         struct bset_tree *t = bch2_bkey_to_bset(b, k);
 182                         printk(" [%zi %zi]", t - b->set,
 183                                k->_data - bset(b, t)->_data);
 184                 }
 185                 panic("\n");
 186         }
 187 }
 188
 189 void bch2_btree_node_iter_verify(struct btree_node_iter *iter,
 190                                  struct btree *b)
 191 {
 192         struct btree_node_iter_set *set, *s2;
 193         struct bkey_packed *k, *p;
 194         struct bset_tree *t;
 195
 196         if (bch2_btree_node_iter_end(iter))
 197                 return;
 198
 199         /* Verify no duplicates: */
 200         btree_node_iter_for_each(iter, set)
 201                 btree_node_iter_for_each(iter, s2)
 202                         BUG_ON(set != s2 && set->end == s2->end);
 203
 204         /* Verify that set->end is correct: */
 205         btree_node_iter_for_each(iter, set) {
 206                 for_each_bset(b, t)
 207                         if (set->end == t->end_offset)
 208                                 goto found;
 209                 BUG();
 210 found:
 211                 BUG_ON(set->k < btree_bkey_first_offset(t) ||
 212                        set->k >= t->end_offset);
 213         }
 214
 215         /* Verify iterator is sorted: */
 216         btree_node_iter_for_each(iter, set)
 217                 BUG_ON(set != iter->data &&
 218                        btree_node_iter_cmp(b, set[-1], set[0]) > 0);
 219
 220         k = bch2_btree_node_iter_peek_all(iter, b);
 221
 222         for_each_bset(b, t) {
 223                 if (iter->data[0].end == t->end_offset)
 224                         continue;
 225
 226                 p = bch2_bkey_prev_all(b, t,
 227                         bch2_btree_node_iter_bset_pos(iter, b, t));
 228
 229                 BUG_ON(p && bkey_iter_cmp(b, k, p) < 0);
 230         }
 231 }
 232
 233 void bch2_verify_insert_pos(struct btree *b, struct bkey_packed *where,
 234                             struct bkey_packed *insert, unsigned clobber_u64s)
 235 {
 236         struct bset_tree *t = bch2_bkey_to_bset(b, where);
 237         struct bkey_packed *prev = bch2_bkey_prev_all(b, t, where);
 238         struct bkey_packed *next = (void *) (where->_data + clobber_u64s);
 239 #if 0
 240         BUG_ON(prev &&
 241                bkey_iter_cmp(b, prev, insert) > 0);
 242 #else
 243         if (prev &&
 244             bkey_iter_cmp(b, prev, insert) > 0) {
 245                 struct bkey k1 = bkey_unpack_key(b, prev);
 246                 struct bkey k2 = bkey_unpack_key(b, insert);
 247                 char buf1[100];
 248                 char buf2[100];
 249
 250                 bch2_dump_btree_node(NULL, b);
 251                 bch2_bkey_to_text(&PBUF(buf1), &k1);
 252                 bch2_bkey_to_text(&PBUF(buf2), &k2);
 253
 254                 panic("prev > insert:\n"
 255                       "prev    key %s\n"
 256                       "insert  key %s\n",
 257                       buf1, buf2);
 258         }
 259 #endif
 260 #if 0
 261         BUG_ON(next != btree_bkey_last(b, t) &&
 262                bkey_iter_cmp(b, insert, next) > 0);
 263 #else
 264         if (next != btree_bkey_last(b, t) &&
 265             bkey_iter_cmp(b, insert, next) > 0) {
 266                 struct bkey k1 = bkey_unpack_key(b, insert);
 267                 struct bkey k2 = bkey_unpack_key(b, next);
 268                 char buf1[100];
 269                 char buf2[100];
 270
 271                 bch2_dump_btree_node(NULL, b);
 272                 bch2_bkey_to_text(&PBUF(buf1), &k1);
 273                 bch2_bkey_to_text(&PBUF(buf2), &k2);
 274
 275                 panic("insert > next:\n"
 276                       "insert  key %s\n"
 277                       "next    key %s\n",
 278                       buf1, buf2);
 279         }
 280 #endif
 281 }
 282
 283 #else
 284
 285 static inline void bch2_btree_node_iter_next_check(struct btree_node_iter *iter,
 286                                                    struct btree *b) {}
 287
 288 #endif
 289
 290 /* Auxiliary search trees */
 291
 292 #define BFLOAT_FAILED_UNPACKED  U8_MAX
 293 #define BFLOAT_FAILED           U8_MAX
 294
 295 struct bkey_float {
 296         u8              exponent;
 297         u8              key_offset;
 298         u16             mantissa;
 299 };
 300 #define BKEY_MANTISSA_BITS      16
 301
 302 static unsigned bkey_float_byte_offset(unsigned idx)
 303 {
 304         return idx * sizeof(struct bkey_float);
 305 }
 306
 307 struct ro_aux_tree {
 308         struct bkey_float       f[0];
 309 };
 310
 311 struct rw_aux_tree {
 312         u16             offset;
 313         struct bpos     k;
 314 };
 315
 316 static unsigned bset_aux_tree_buf_end(const struct bset_tree *t)
 317 {
 318         BUG_ON(t->aux_data_offset == U16_MAX);
 319
 320         switch (bset_aux_tree_type(t)) {
 321         case BSET_NO_AUX_TREE:
 322                 return t->aux_data_offset;
 323         case BSET_RO_AUX_TREE:
 324                 return t->aux_data_offset +
 325                         DIV_ROUND_UP(t->size * sizeof(struct bkey_float) +
 326                                      t->size * sizeof(u8), 8);
 327         case BSET_RW_AUX_TREE:
 328                 return t->aux_data_offset +
 329                         DIV_ROUND_UP(sizeof(struct rw_aux_tree) * t->size, 8);
 330         default:
 331                 BUG();
 332         }
 333 }
 334
 335 static unsigned bset_aux_tree_buf_start(const struct btree *b,
 336                                         const struct bset_tree *t)
 337 {
 338         return t == b->set
 339                 ? DIV_ROUND_UP(b->unpack_fn_len, 8)
 340                 : bset_aux_tree_buf_end(t - 1);
 341 }
 342
 343 static void *__aux_tree_base(const struct btree *b,
 344                              const struct bset_tree *t)
 345 {
 346         return b->aux_data + t->aux_data_offset * 8;
 347 }
 348
 349 static struct ro_aux_tree *ro_aux_tree_base(const struct btree *b,
 350                                             const struct bset_tree *t)
 351 {
 352         EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
 353
 354         return __aux_tree_base(b, t);
 355 }
 356
 357 static u8 *ro_aux_tree_prev(const struct btree *b,
 358                             const struct bset_tree *t)
 359 {
 360         EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
 361
 362         return __aux_tree_base(b, t) + bkey_float_byte_offset(t->size);
 363 }
 364
 365 static struct bkey_float *bkey_float(const struct btree *b,
 366                                      const struct bset_tree *t,
 367                                      unsigned idx)
 368 {
 369         return ro_aux_tree_base(b, t)->f + idx;
 370 }
 371
 372 static void bset_aux_tree_verify(struct btree *b)
 373 {
 374 #ifdef CONFIG_BCACHEFS_DEBUG
 375         struct bset_tree *t;
 376
 377         for_each_bset(b, t) {
 378                 if (t->aux_data_offset == U16_MAX)
 379                         continue;
 380
 381                 BUG_ON(t != b->set &&
 382                        t[-1].aux_data_offset == U16_MAX);
 383
 384                 BUG_ON(t->aux_data_offset < bset_aux_tree_buf_start(b, t));
 385                 BUG_ON(t->aux_data_offset > btree_aux_data_u64s(b));
 386                 BUG_ON(bset_aux_tree_buf_end(t) > btree_aux_data_u64s(b));
 387         }
 388 #endif
 389 }
 390
 391 void bch2_btree_keys_init(struct btree *b, bool *expensive_debug_checks)
 392 {
 393         unsigned i;
 394
 395         b->nsets                = 0;
 396         memset(&b->nr, 0, sizeof(b->nr));
 397 #ifdef CONFIG_BCACHEFS_DEBUG
 398         b->expensive_debug_checks = expensive_debug_checks;
 399 #endif
 400         for (i = 0; i < MAX_BSETS; i++)
 401                 b->set[i].data_offset = U16_MAX;
 402
 403         bch2_bset_set_no_aux_tree(b, b->set);
 404 }
 405
 406 /* Binary tree stuff for auxiliary search trees */
 407
 408 /*
 409  * Cacheline/offset <-> bkey pointer arithmetic:
 410  *
 411  * t->tree is a binary search tree in an array; each node corresponds to a key
 412  * in one cacheline in t->set (BSET_CACHELINE bytes).
 413  *
 414  * This means we don't have to store the full index of the key that a node in
 415  * the binary tree points to; eytzinger1_to_inorder() gives us the cacheline, and
 416  * then bkey_float->m gives us the offset within that cacheline, in units of 8
 417  * bytes.
 418  *
 419  * cacheline_to_bkey() and friends abstract out all the pointer arithmetic to
 420  * make this work.
 421  *
 422  * To construct the bfloat for an arbitrary key we need to know what the key
 423  * immediately preceding it is: we have to check if the two keys differ in the
 424  * bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size
 425  * of the previous key so we can walk backwards to it from t->tree[j]'s key.
 426  */
 427
 428 static inline void *bset_cacheline(const struct btree *b,
 429                                    const struct bset_tree *t,
 430                                    unsigned cacheline)
 431 {
 432         return (void *) round_down((unsigned long) btree_bkey_first(b, t),
 433                                    L1_CACHE_BYTES) +
 434                 cacheline * BSET_CACHELINE;
 435 }
 436
 437 static struct bkey_packed *cacheline_to_bkey(const struct btree *b,
 438                                              const struct bset_tree *t,
 439                                              unsigned cacheline,
 440                                              unsigned offset)
 441 {
 442         return bset_cacheline(b, t, cacheline) + offset * 8;
 443 }
 444
 445 static unsigned bkey_to_cacheline(const struct btree *b,
 446                                   const struct bset_tree *t,
 447                                   const struct bkey_packed *k)
 448 {
 449         return ((void *) k - bset_cacheline(b, t, 0)) / BSET_CACHELINE;
 450 }
 451
 452 static ssize_t __bkey_to_cacheline_offset(const struct btree *b,
 453                                           const struct bset_tree *t,
 454                                           unsigned cacheline,
 455                                           const struct bkey_packed *k)
 456 {
 457         return (u64 *) k - (u64 *) bset_cacheline(b, t, cacheline);
 458 }
 459
 460 static unsigned bkey_to_cacheline_offset(const struct btree *b,
 461                                          const struct bset_tree *t,
 462                                          unsigned cacheline,
 463                                          const struct bkey_packed *k)
 464 {
 465         size_t m = __bkey_to_cacheline_offset(b, t, cacheline, k);
 466
 467         EBUG_ON(m > U8_MAX);
 468         return m;
 469 }
 470
 471 static inline struct bkey_packed *tree_to_bkey(const struct btree *b,
 472                                                const struct bset_tree *t,
 473                                                unsigned j)
 474 {
 475         return cacheline_to_bkey(b, t,
 476                         __eytzinger1_to_inorder(j, t->size, t->extra),
 477                         bkey_float(b, t, j)->key_offset);
 478 }
 479
 480 static struct bkey_packed *tree_to_prev_bkey(const struct btree *b,
 481                                              const struct bset_tree *t,
 482                                              unsigned j)
 483 {
 484         unsigned prev_u64s = ro_aux_tree_prev(b, t)[j];
 485
 486         return (void *) (tree_to_bkey(b, t, j)->_data - prev_u64s);
 487 }
 488
 489 static struct rw_aux_tree *rw_aux_tree(const struct btree *b,
 490                                        const struct bset_tree *t)
 491 {
 492         EBUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);
 493
 494         return __aux_tree_base(b, t);
 495 }
 496
 497 /*
 498  * For the write set - the one we're currently inserting keys into - we don't
 499  * maintain a full search tree, we just keep a simple lookup table in t->prev.
 500  */
 501 static struct bkey_packed *rw_aux_to_bkey(const struct btree *b,
 502                                           struct bset_tree *t,
 503                                           unsigned j)
 504 {
 505         return __btree_node_offset_to_key(b, rw_aux_tree(b, t)[j].offset);
 506 }
 507
 508 static void rw_aux_tree_set(const struct btree *b, struct bset_tree *t,
 509                             unsigned j, struct bkey_packed *k)
 510 {
 511         EBUG_ON(k >= btree_bkey_last(b, t));
 512
 513         rw_aux_tree(b, t)[j] = (struct rw_aux_tree) {
 514                 .offset = __btree_node_key_to_offset(b, k),
 515                 .k      = bkey_unpack_pos(b, k),
 516         };
 517 }
 518
 519 static void bch2_bset_verify_rw_aux_tree(struct btree *b,
 520                                         struct bset_tree *t)
 521 {
 522         struct bkey_packed *k = btree_bkey_first(b, t);
 523         unsigned j = 0;
 524
 525         if (!btree_keys_expensive_checks(b))
 526                 return;
 527
 528         BUG_ON(bset_has_ro_aux_tree(t));
 529
 530         if (!bset_has_rw_aux_tree(t))
 531                 return;
 532
 533         BUG_ON(t->size < 1);
 534         BUG_ON(rw_aux_to_bkey(b, t, j) != k);
 535
 536         goto start;
 537         while (1) {
 538                 if (rw_aux_to_bkey(b, t, j) == k) {
 539                         BUG_ON(bkey_cmp(rw_aux_tree(b, t)[j].k,
 540                                         bkey_unpack_pos(b, k)));
 541 start:
 542                         if (++j == t->size)
 543                                 break;
 544
 545                         BUG_ON(rw_aux_tree(b, t)[j].offset <=
 546                                rw_aux_tree(b, t)[j - 1].offset);
 547                 }
 548
 549                 k = bkey_next_skip_noops(k, btree_bkey_last(b, t));
 550                 BUG_ON(k >= btree_bkey_last(b, t));
 551         }
 552 }
 553
 554 /* returns idx of first entry >= offset: */
 555 static unsigned rw_aux_tree_bsearch(struct btree *b,
 556                                     struct bset_tree *t,
 557                                     unsigned offset)
 558 {
 559         unsigned bset_offs = offset - btree_bkey_first_offset(t);
 560         unsigned bset_u64s = t->end_offset - btree_bkey_first_offset(t);
 561         unsigned idx = bset_u64s ? bset_offs * t->size / bset_u64s : 0;
 562
 563         EBUG_ON(bset_aux_tree_type(t) != BSET_RW_AUX_TREE);
 564         EBUG_ON(!t->size);
 565         EBUG_ON(idx > t->size);
 566
 567         while (idx < t->size &&
 568                rw_aux_tree(b, t)[idx].offset < offset)
 569                 idx++;
 570
 571         while (idx &&
 572                rw_aux_tree(b, t)[idx - 1].offset >= offset)
 573                 idx--;
 574
 575         EBUG_ON(idx < t->size &&
 576                 rw_aux_tree(b, t)[idx].offset < offset);
 577         EBUG_ON(idx && rw_aux_tree(b, t)[idx - 1].offset >= offset);
 578         EBUG_ON(idx + 1 < t->size &&
 579                 rw_aux_tree(b, t)[idx].offset ==
 580                 rw_aux_tree(b, t)[idx + 1].offset);
 581
 582         return idx;
 583 }
 584
 585 static inline unsigned bkey_mantissa(const struct bkey_packed *k,
 586                                      const struct bkey_float *f,
 587                                      unsigned idx)
 588 {
 589         u64 v;
 590
 591         EBUG_ON(!bkey_packed(k));
 592
 593         v = get_unaligned((u64 *) (((u8 *) k->_data) + (f->exponent >> 3)));
 594
 595         /*
 596          * In little endian, we're shifting off low bits (and then the bits we
 597          * want are at the low end), in big endian we're shifting off high bits
 598          * (and then the bits we want are at the high end, so we shift them
 599          * back down):
 600          */
 601 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 602         v >>= f->exponent & 7;
 603 #else
 604         v >>= 64 - (f->exponent & 7) - BKEY_MANTISSA_BITS;
 605 #endif
 606         return (u16) v;
 607 }
 608
 609 static void make_bfloat(struct btree *b, struct bset_tree *t,
 610                         unsigned j,
 611                         struct bkey_packed *min_key,
 612                         struct bkey_packed *max_key)
 613 {
 614         struct bkey_float *f = bkey_float(b, t, j);
 615         struct bkey_packed *m = tree_to_bkey(b, t, j);
 616         struct bkey_packed *l, *r;
 617         unsigned mantissa;
 618         int shift, exponent, high_bit;
 619
 620         if (is_power_of_2(j)) {
 621                 l = min_key;
 622
 623                 if (!l->u64s) {
 624                         if (!bkey_pack_pos(l, b->data->min_key, b)) {
 625                                 struct bkey_i tmp;
 626
 627                                 bkey_init(&tmp.k);
 628                                 tmp.k.p = b->data->min_key;
 629                                 bkey_copy(l, &tmp);
 630                         }
 631                 }
 632         } else {
 633                 l = tree_to_prev_bkey(b, t, j >> ffs(j));
 634
 635                 EBUG_ON(m < l);
 636         }
 637
 638         if (is_power_of_2(j + 1)) {
 639                 r = max_key;
 640
 641                 if (!r->u64s) {
 642                         if (!bkey_pack_pos(r, t->max_key, b)) {
 643                                 struct bkey_i tmp;
 644
 645                                 bkey_init(&tmp.k);
 646                                 tmp.k.p = t->max_key;
 647                                 bkey_copy(r, &tmp);
 648                         }
 649                 }
 650         } else {
 651                 r = tree_to_bkey(b, t, j >> (ffz(j) + 1));
 652
 653                 EBUG_ON(m > r);
 654         }
 655
 656         /*
 657          * for failed bfloats, the lookup code falls back to comparing against
 658          * the original key.
 659          */
 660
 661         if (!bkey_packed(l) || !bkey_packed(r) || !bkey_packed(m) ||
 662             !b->nr_key_bits) {
 663                 f->exponent = BFLOAT_FAILED_UNPACKED;
 664                 return;
 665         }
 666
 667         /*
 668          * The greatest differing bit of l and r is the first bit we must
 669          * include in the bfloat mantissa we're creating in order to do
 670          * comparisons - that bit always becomes the high bit of
 671          * bfloat->mantissa, and thus the exponent we're calculating here is
 672          * the position of what will become the low bit in bfloat->mantissa:
 673          *
 674          * Note that this may be negative - we may be running off the low end
 675          * of the key: we handle this later:
 676          */
 677         high_bit = max(bch2_bkey_greatest_differing_bit(b, l, r),
 678                        min_t(unsigned, BKEY_MANTISSA_BITS, b->nr_key_bits) - 1);
 679         exponent = high_bit - (BKEY_MANTISSA_BITS - 1);
 680
 681         /*
 682          * Then we calculate the actual shift value, from the start of the key
 683          * (k->_data), to get the key bits starting at exponent:
 684          */
 685 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 686         shift = (int) (b->format.key_u64s * 64 - b->nr_key_bits) + exponent;
 687
 688         EBUG_ON(shift + BKEY_MANTISSA_BITS > b->format.key_u64s * 64);
 689 #else
 690         shift = high_bit_offset +
 691                 b->nr_key_bits -
 692                 exponent -
 693                 BKEY_MANTISSA_BITS;
 694
 695         EBUG_ON(shift < KEY_PACKED_BITS_START);
 696 #endif
 697         EBUG_ON(shift < 0 || shift >= BFLOAT_FAILED);
 698
 699         f->exponent = shift;
 700         mantissa = bkey_mantissa(m, f, j);
 701
 702         /*
 703          * If we've got garbage bits, set them to all 1s - it's legal for the
 704          * bfloat to compare larger than the original key, but not smaller:
 705          */
 706         if (exponent < 0)
 707                 mantissa |= ~(~0U << -exponent);
 708
 709         f->mantissa = mantissa;
 710 }
 711
 712 /* bytes remaining - only valid for last bset: */
 713 static unsigned __bset_tree_capacity(struct btree *b, struct bset_tree *t)
 714 {
 715         bset_aux_tree_verify(b);
 716
 717         return btree_aux_data_bytes(b) - t->aux_data_offset * sizeof(u64);
 718 }
 719
 720 static unsigned bset_ro_tree_capacity(struct btree *b, struct bset_tree *t)
 721 {
 722         return __bset_tree_capacity(b, t) /
 723                 (sizeof(struct bkey_float) + sizeof(u8));
 724 }
 725
 726 static unsigned bset_rw_tree_capacity(struct btree *b, struct bset_tree *t)
 727 {
 728         return __bset_tree_capacity(b, t) / sizeof(struct rw_aux_tree);
 729 }
 730
 731 static void __build_rw_aux_tree(struct btree *b, struct bset_tree *t)
 732 {
 733         struct bkey_packed *k;
 734
 735         t->size = 1;
 736         t->extra = BSET_RW_AUX_TREE_VAL;
 737         rw_aux_tree(b, t)[0].offset =
 738                 __btree_node_key_to_offset(b, btree_bkey_first(b, t));
 739
 740         bset_tree_for_each_key(b, t, k) {
 741                 if (t->size == bset_rw_tree_capacity(b, t))
 742                         break;
 743
 744                 if ((void *) k - (void *) rw_aux_to_bkey(b, t, t->size - 1) >
 745                     L1_CACHE_BYTES)
 746                         rw_aux_tree_set(b, t, t->size++, k);
 747         }
 748 }
 749
 750 static void __build_ro_aux_tree(struct btree *b, struct bset_tree *t)
 751 {
 752         struct bkey_packed *prev = NULL, *k = btree_bkey_first(b, t);
 753         struct bkey_packed min_key, max_key;
 754         unsigned j, cacheline = 1;
 755
 756         /* signal to make_bfloat() that they're uninitialized: */
 757         min_key.u64s = max_key.u64s = 0;
 758
 759         t->size = min(bkey_to_cacheline(b, t, btree_bkey_last(b, t)),
 760                       bset_ro_tree_capacity(b, t));
 761 retry:
 762         if (t->size < 2) {
 763                 t->size = 0;
 764                 t->extra = BSET_NO_AUX_TREE_VAL;
 765                 return;
 766         }
 767
 768         t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1;
 769
 770         /* First we figure out where the first key in each cacheline is */
 771         eytzinger1_for_each(j, t->size) {
 772                 while (bkey_to_cacheline(b, t, k) < cacheline)
 773                         prev = k, k = bkey_next_skip_noops(k, btree_bkey_last(b, t));
 774
 775                 if (k >= btree_bkey_last(b, t)) {
 776                         /* XXX: this path sucks */
 777                         t->size--;
 778                         goto retry;
 779                 }
 780
 781                 ro_aux_tree_prev(b, t)[j] = prev->u64s;
 782                 bkey_float(b, t, j)->key_offset =
 783                         bkey_to_cacheline_offset(b, t, cacheline++, k);
 784
 785                 EBUG_ON(tree_to_prev_bkey(b, t, j) != prev);
 786                 EBUG_ON(tree_to_bkey(b, t, j) != k);
 787         }
 788
 789         while (k != btree_bkey_last(b, t))
 790                 prev = k, k = bkey_next_skip_noops(k, btree_bkey_last(b, t));
 791
 792         t->max_key = bkey_unpack_pos(b, prev);
 793
 794         /* Then we build the tree */
 795         eytzinger1_for_each(j, t->size)
 796                 make_bfloat(b, t, j, &min_key, &max_key);
 797 }
 798
 799 static void bset_alloc_tree(struct btree *b, struct bset_tree *t)
 800 {
 801         struct bset_tree *i;
 802
 803         for (i = b->set; i != t; i++)
 804                 BUG_ON(bset_has_rw_aux_tree(i));
 805
 806         bch2_bset_set_no_aux_tree(b, t);
 807
 808         /* round up to next cacheline: */
 809         t->aux_data_offset = round_up(bset_aux_tree_buf_start(b, t),
 810                                       SMP_CACHE_BYTES / sizeof(u64));
 811
 812         bset_aux_tree_verify(b);
 813 }
 814
 815 void bch2_bset_build_aux_tree(struct btree *b, struct bset_tree *t,
 816                              bool writeable)
 817 {
 818         if (writeable
 819             ? bset_has_rw_aux_tree(t)
 820             : bset_has_ro_aux_tree(t))
 821                 return;
 822
 823         bset_alloc_tree(b, t);
 824
 825         if (!__bset_tree_capacity(b, t))
 826                 return;
 827
 828         if (writeable)
 829                 __build_rw_aux_tree(b, t);
 830         else
 831                 __build_ro_aux_tree(b, t);
 832
 833         bset_aux_tree_verify(b);
 834 }
 835
 836 void bch2_bset_init_first(struct btree *b, struct bset *i)
 837 {
 838         struct bset_tree *t;
 839
 840         BUG_ON(b->nsets);
 841
 842         memset(i, 0, sizeof(*i));
 843         get_random_bytes(&i->seq, sizeof(i->seq));
 844         SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);
 845
 846         t = &b->set[b->nsets++];
 847         set_btree_bset(b, t, i);
 848 }
 849
 850 void bch2_bset_init_next(struct bch_fs *c, struct btree *b,
 851                          struct btree_node_entry *bne)
 852 {
 853         struct bset *i = &bne->keys;
 854         struct bset_tree *t;
 855
 856         BUG_ON(bset_byte_offset(b, bne) >= btree_bytes(c));
 857         BUG_ON((void *) bne < (void *) btree_bkey_last(b, bset_tree_last(b)));
 858         BUG_ON(b->nsets >= MAX_BSETS);
 859
 860         memset(i, 0, sizeof(*i));
 861         i->seq = btree_bset_first(b)->seq;
 862         SET_BSET_BIG_ENDIAN(i, CPU_BIG_ENDIAN);
 863
 864         t = &b->set[b->nsets++];
 865         set_btree_bset(b, t, i);
 866 }
 867
 868 /*
 869  * find _some_ key in the same bset as @k that precedes @k - not necessarily the
 870  * immediate predecessor:
 871  */
 872 static struct bkey_packed *__bkey_prev(struct btree *b, struct bset_tree *t,
 873                                        struct bkey_packed *k)
 874 {
 875         struct bkey_packed *p;
 876         unsigned offset;
 877         int j;
 878
 879         EBUG_ON(k < btree_bkey_first(b, t) ||
 880                 k > btree_bkey_last(b, t));
 881
 882         if (k == btree_bkey_first(b, t))
 883                 return NULL;
 884
 885         switch (bset_aux_tree_type(t)) {
 886         case BSET_NO_AUX_TREE:
 887                 p = btree_bkey_first(b, t);
 888                 break;
 889         case BSET_RO_AUX_TREE:
 890                 j = min_t(unsigned, t->size - 1, bkey_to_cacheline(b, t, k));
 891
 892                 do {
 893                         p = j ? tree_to_bkey(b, t,
 894                                         __inorder_to_eytzinger1(j--,
 895                                                         t->size, t->extra))
 896                               : btree_bkey_first(b, t);
 897                 } while (p >= k);
 898                 break;
 899         case BSET_RW_AUX_TREE:
 900                 offset = __btree_node_key_to_offset(b, k);
 901                 j = rw_aux_tree_bsearch(b, t, offset);
 902                 p = j ? rw_aux_to_bkey(b, t, j - 1)
 903                       : btree_bkey_first(b, t);
 904                 break;
 905         }
 906
 907         return p;
 908 }
 909
 910 struct bkey_packed *bch2_bkey_prev_filter(struct btree *b,
 911                                           struct bset_tree *t,
 912                                           struct bkey_packed *k,
 913                                           unsigned min_key_type)
 914 {
 915         struct bkey_packed *p, *i, *ret = NULL, *orig_k = k;
 916
 917         while ((p = __bkey_prev(b, t, k)) && !ret) {
 918                 for (i = p; i != k; i = bkey_next_skip_noops(i, k))
 919                         if (i->type >= min_key_type)
 920                                 ret = i;
 921
 922                 k = p;
 923         }
 924
 925         if (btree_keys_expensive_checks(b)) {
 926                 BUG_ON(ret >= orig_k);
 927
 928                 for (i = ret
 929                         ? bkey_next_skip_noops(ret, orig_k)
 930                         : btree_bkey_first(b, t);
 931                      i != orig_k;
 932                      i = bkey_next_skip_noops(i, orig_k))
 933                         BUG_ON(i->type >= min_key_type);
 934         }
 935
 936         return ret;
 937 }
 938
 939 /* Insert */
 940
 941 static void rw_aux_tree_fix_invalidated_key(struct btree *b,
 942                                             struct bset_tree *t,
 943                                             struct bkey_packed *k)
 944 {
 945         unsigned offset = __btree_node_key_to_offset(b, k);
 946         unsigned j = rw_aux_tree_bsearch(b, t, offset);
 947
 948         if (j < t->size &&
 949             rw_aux_tree(b, t)[j].offset == offset)
 950                 rw_aux_tree_set(b, t, j, k);
 951
 952         bch2_bset_verify_rw_aux_tree(b, t);
 953 }
 954
 955 static void ro_aux_tree_fix_invalidated_key(struct btree *b,
 956                                             struct bset_tree *t,
 957                                             struct bkey_packed *k)
 958 {
 959         struct bkey_packed min_key, max_key;
 960         unsigned inorder, j;
 961
 962         EBUG_ON(bset_aux_tree_type(t) != BSET_RO_AUX_TREE);
 963
 964         /* signal to make_bfloat() that they're uninitialized: */
 965         min_key.u64s = max_key.u64s = 0;
 966
 967         if (bkey_next_skip_noops(k, btree_bkey_last(b, t)) == btree_bkey_last(b, t)) {
 968                 t->max_key = bkey_unpack_pos(b, k);
 969
 970                 for (j = 1; j < t->size; j = j * 2 + 1)
 971                         make_bfloat(b, t, j, &min_key, &max_key);
 972         }
 973
 974         inorder = bkey_to_cacheline(b, t, k);
 975
 976         if (inorder &&
 977             inorder < t->size) {
 978                 j = __inorder_to_eytzinger1(inorder, t->size, t->extra);
 979
 980                 if (k == tree_to_bkey(b, t, j)) {
 981                         /* Fix the node this key corresponds to */
 982                         make_bfloat(b, t, j, &min_key, &max_key);
 983
 984                         /* Children for which this key is the right boundary */
 985                         for (j = eytzinger1_left_child(j);
 986                              j < t->size;
 987                              j = eytzinger1_right_child(j))
 988                                 make_bfloat(b, t, j, &min_key, &max_key);
 989                 }
 990         }
 991
 992         if (inorder + 1 < t->size) {
 993                 j = __inorder_to_eytzinger1(inorder + 1, t->size, t->extra);
 994
 995                 if (k == tree_to_prev_bkey(b, t, j)) {
 996                         make_bfloat(b, t, j, &min_key, &max_key);
 997
 998                         /* Children for which this key is the left boundary */
 999                         for (j = eytzinger1_right_child(j);
1000                              j < t->size;
1001                              j = eytzinger1_left_child(j))
1002                                 make_bfloat(b, t, j, &min_key, &max_key);
1003                 }
1004         }
1005 }
1006
1007 /**
1008  * bch2_bset_fix_invalidated_key() - given an existing  key @k that has been
1009  * modified, fix any auxiliary search tree by remaking all the nodes in the
1010  * auxiliary search tree that @k corresponds to
1011  */
1012 void bch2_bset_fix_invalidated_key(struct btree *b, struct bkey_packed *k)
1013 {
1014         struct bset_tree *t = bch2_bkey_to_bset(b, k);
1015
1016         switch (bset_aux_tree_type(t)) {
1017         case BSET_NO_AUX_TREE:
1018                 break;
1019         case BSET_RO_AUX_TREE:
1020                 ro_aux_tree_fix_invalidated_key(b, t, k);
1021                 break;
1022         case BSET_RW_AUX_TREE:
1023                 rw_aux_tree_fix_invalidated_key(b, t, k);
1024                 break;
1025         }
1026 }
1027
1028 static void bch2_bset_fix_lookup_table(struct btree *b,
1029                                        struct bset_tree *t,
1030                                        struct bkey_packed *_where,
1031                                        unsigned clobber_u64s,
1032                                        unsigned new_u64s)
1033 {
1034         int shift = new_u64s - clobber_u64s;
1035         unsigned l, j, where = __btree_node_key_to_offset(b, _where);
1036
1037         EBUG_ON(bset_has_ro_aux_tree(t));
1038
1039         if (!bset_has_rw_aux_tree(t))
1040                 return;
1041
1042         /* returns first entry >= where */
1043         l = rw_aux_tree_bsearch(b, t, where);
1044
1045         if (!l) /* never delete first entry */
1046                 l++;
1047         else if (l < t->size &&
1048                  where < t->end_offset &&
1049                  rw_aux_tree(b, t)[l].offset == where)
1050                 rw_aux_tree_set(b, t, l++, _where);
1051
1052         /* l now > where */
1053
1054         for (j = l;
1055              j < t->size &&
1056              rw_aux_tree(b, t)[j].offset < where + clobber_u64s;
1057              j++)
1058                 ;
1059
1060         if (j < t->size &&
1061             rw_aux_tree(b, t)[j].offset + shift ==
1062             rw_aux_tree(b, t)[l - 1].offset)
1063                 j++;
1064
1065         memmove(&rw_aux_tree(b, t)[l],
1066                 &rw_aux_tree(b, t)[j],
1067                 (void *) &rw_aux_tree(b, t)[t->size] -
1068                 (void *) &rw_aux_tree(b, t)[j]);
1069         t->size -= j - l;
1070
1071         for (j = l; j < t->size; j++)
1072                rw_aux_tree(b, t)[j].offset += shift;
1073
1074         EBUG_ON(l < t->size &&
1075                 rw_aux_tree(b, t)[l].offset ==
1076                 rw_aux_tree(b, t)[l - 1].offset);
1077
1078         if (t->size < bset_rw_tree_capacity(b, t) &&
1079             (l < t->size
1080              ? rw_aux_tree(b, t)[l].offset
1081              : t->end_offset) -
1082             rw_aux_tree(b, t)[l - 1].offset >
1083             L1_CACHE_BYTES / sizeof(u64)) {
1084                 struct bkey_packed *start = rw_aux_to_bkey(b, t, l - 1);
1085                 struct bkey_packed *end = l < t->size
1086                         ? rw_aux_to_bkey(b, t, l)
1087                         : btree_bkey_last(b, t);
1088                 struct bkey_packed *k = start;
1089
1090                 while (1) {
1091                         k = bkey_next_skip_noops(k, end);
1092                         if (k == end)
1093                                 break;
1094
1095                         if ((void *) k - (void *) start >= L1_CACHE_BYTES) {
1096                                 memmove(&rw_aux_tree(b, t)[l + 1],
1097                                         &rw_aux_tree(b, t)[l],
1098                                         (void *) &rw_aux_tree(b, t)[t->size] -
1099                                         (void *) &rw_aux_tree(b, t)[l]);
1100                                 t->size++;
1101                                 rw_aux_tree_set(b, t, l, k);
1102                                 break;
1103                         }
1104                 }
1105         }
1106
1107         bch2_bset_verify_rw_aux_tree(b, t);
1108         bset_aux_tree_verify(b);
1109 }
1110
1111 void bch2_bset_insert(struct btree *b,
1112                       struct btree_node_iter *iter,
1113                       struct bkey_packed *where,
1114                       struct bkey_i *insert,
1115                       unsigned clobber_u64s)
1116 {
1117         struct bkey_format *f = &b->format;
1118         struct bset_tree *t = bset_tree_last(b);
1119         struct bkey_packed packed, *src = bkey_to_packed(insert);
1120
1121         bch2_bset_verify_rw_aux_tree(b, t);
1122         bch2_verify_insert_pos(b, where, bkey_to_packed(insert), clobber_u64s);
1123
1124         if (bch2_bkey_pack_key(&packed, &insert->k, f))
1125                 src = &packed;
1126
1127         if (!bkey_whiteout(&insert->k))
1128                 btree_keys_account_key_add(&b->nr, t - b->set, src);
1129
1130         if (src->u64s != clobber_u64s) {
1131                 u64 *src_p = where->_data + clobber_u64s;
1132                 u64 *dst_p = where->_data + src->u64s;
1133
1134                 EBUG_ON((int) le16_to_cpu(bset(b, t)->u64s) <
1135                         (int) clobber_u64s - src->u64s);
1136
1137                 memmove_u64s(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);
1138                 le16_add_cpu(&bset(b, t)->u64s, src->u64s - clobber_u64s);
1139                 set_btree_bset_end(b, t);
1140         }
1141
1142         memcpy_u64s(where, src,
1143                     bkeyp_key_u64s(f, src));
1144         memcpy_u64s(bkeyp_val(f, where), &insert->v,
1145                     bkeyp_val_u64s(f, src));
1146
1147         if (src->u64s != clobber_u64s)
1148                 bch2_bset_fix_lookup_table(b, t, where, clobber_u64s, src->u64s);
1149
1150         bch2_verify_btree_nr_keys(b);
1151 }
1152
1153 void bch2_bset_delete(struct btree *b,
1154                       struct bkey_packed *where,
1155                       unsigned clobber_u64s)
1156 {
1157         struct bset_tree *t = bset_tree_last(b);
1158         u64 *src_p = where->_data + clobber_u64s;
1159         u64 *dst_p = where->_data;
1160
1161         bch2_bset_verify_rw_aux_tree(b, t);
1162
1163         EBUG_ON(le16_to_cpu(bset(b, t)->u64s) < clobber_u64s);
1164
1165         memmove_u64s_down(dst_p, src_p, btree_bkey_last(b, t)->_data - src_p);
1166         le16_add_cpu(&bset(b, t)->u64s, -clobber_u64s);
1167         set_btree_bset_end(b, t);
1168
1169         bch2_bset_fix_lookup_table(b, t, where, clobber_u64s, 0);
1170 }
1171
1172 /* Lookup */
1173
1174 __flatten
1175 static struct bkey_packed *bset_search_write_set(const struct btree *b,
1176                                 struct bset_tree *t,
1177                                 struct bpos *search,
1178                                 const struct bkey_packed *packed_search)
1179 {
1180         unsigned l = 0, r = t->size;
1181
1182         while (l + 1 != r) {
1183                 unsigned m = (l + r) >> 1;
1184
1185                 if (bkey_cmp(rw_aux_tree(b, t)[m].k, *search) < 0)
1186                         l = m;
1187                 else
1188                         r = m;
1189         }
1190
1191         return rw_aux_to_bkey(b, t, l);
1192 }
1193
1194 static inline void prefetch_four_cachelines(void *p)
1195 {
1196 #ifdef CONFIG_X86_64
1197         asm(".intel_syntax noprefix;"
1198             "prefetcht0 [%0 - 127 + 64 * 0];"
1199             "prefetcht0 [%0 - 127 + 64 * 1];"
1200             "prefetcht0 [%0 - 127 + 64 * 2];"
1201             "prefetcht0 [%0 - 127 + 64 * 3];"
1202             ".att_syntax prefix;"
1203             :
1204             : "r" (p + 127));
1205 #else
1206         prefetch(p + L1_CACHE_BYTES * 0);
1207         prefetch(p + L1_CACHE_BYTES * 1);
1208         prefetch(p + L1_CACHE_BYTES * 2);
1209         prefetch(p + L1_CACHE_BYTES * 3);
1210 #endif
1211 }
1212
1213 static inline bool bkey_mantissa_bits_dropped(const struct btree *b,
1214                                               const struct bkey_float *f,
1215                                               unsigned idx)
1216 {
1217 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
1218         unsigned key_bits_start = b->format.key_u64s * 64 - b->nr_key_bits;
1219
1220         return f->exponent > key_bits_start;
1221 #else
1222         unsigned key_bits_end = high_bit_offset + b->nr_key_bits;
1223
1224         return f->exponent + BKEY_MANTISSA_BITS < key_bits_end;
1225 #endif
1226 }
1227
1228 __flatten
1229 static struct bkey_packed *bset_search_tree(const struct btree *b,
1230                                 struct bset_tree *t,
1231                                 struct bpos *search,
1232                                 const struct bkey_packed *packed_search)
1233 {
1234         struct ro_aux_tree *base = ro_aux_tree_base(b, t);
1235         struct bkey_float *f;
1236         struct bkey_packed *k;
1237         unsigned inorder, n = 1, l, r;
1238         int cmp;
1239
1240         do {
1241                 if (likely(n << 4 < t->size))
1242                         prefetch(&base->f[n << 4]);
1243
1244                 f = &base->f[n];
1245
1246                 if (!unlikely(packed_search))
1247                         goto slowpath;
1248                 if (unlikely(f->exponent >= BFLOAT_FAILED))
1249                         goto slowpath;
1250
1251                 l = f->mantissa;
1252                 r = bkey_mantissa(packed_search, f, n);
1253
1254                 if (unlikely(l == r) && bkey_mantissa_bits_dropped(b, f, n))
1255                         goto slowpath;
1256
1257                 n = n * 2 + (l < r);
1258                 continue;
1259 slowpath:
1260                 k = tree_to_bkey(b, t, n);
1261                 cmp = bkey_cmp_p_or_unp(b, k, packed_search, search);
1262                 if (!cmp)
1263                         return k;
1264
1265                 n = n * 2 + (cmp < 0);
1266         } while (n < t->size);
1267
1268         inorder = __eytzinger1_to_inorder(n >> 1, t->size, t->extra);
1269
1270         /*
1271          * n would have been the node we recursed to - the low bit tells us if
1272          * we recursed left or recursed right.
1273          */
1274         if (likely(!(n & 1))) {
1275                 --inorder;
1276                 if (unlikely(!inorder))
1277                         return btree_bkey_first(b, t);
1278
1279                 f = &base->f[eytzinger1_prev(n >> 1, t->size)];
1280         }
1281
1282         return cacheline_to_bkey(b, t, inorder, f->key_offset);
1283 }
1284
1285 static __always_inline __flatten
1286 struct bkey_packed *__bch2_bset_search(struct btree *b,
1287                                 struct bset_tree *t,
1288                                 struct bpos *search,
1289                                 const struct bkey_packed *lossy_packed_search)
1290 {
1291
1292         /*
1293          * First, we search for a cacheline, then lastly we do a linear search
1294          * within that cacheline.
1295          *
1296          * To search for the cacheline, there's three different possibilities:
1297          *  * The set is too small to have a search tree, so we just do a linear
1298          *    search over the whole set.
1299          *  * The set is the one we're currently inserting into; keeping a full
1300          *    auxiliary search tree up to date would be too expensive, so we
1301          *    use a much simpler lookup table to do a binary search -
1302          *    bset_search_write_set().
1303          *  * Or we use the auxiliary search tree we constructed earlier -
1304          *    bset_search_tree()
1305          */
1306
1307         switch (bset_aux_tree_type(t)) {
1308         case BSET_NO_AUX_TREE:
1309                 return btree_bkey_first(b, t);
1310         case BSET_RW_AUX_TREE:
1311                 return bset_search_write_set(b, t, search, lossy_packed_search);
1312         case BSET_RO_AUX_TREE:
1313                 /*
1314                  * Each node in the auxiliary search tree covers a certain range
1315                  * of bits, and keys above and below the set it covers might
1316                  * differ outside those bits - so we have to special case the
1317                  * start and end - handle that here:
1318                  */
1319
1320                 if (bkey_cmp(*search, t->max_key) > 0)
1321                         return btree_bkey_last(b, t);
1322
1323                 return bset_search_tree(b, t, search, lossy_packed_search);
1324         default:
1325                 unreachable();
1326         }
1327 }
1328
1329 static __always_inline __flatten
1330 struct bkey_packed *bch2_bset_search_linear(struct btree *b,
1331                                 struct bset_tree *t,
1332                                 struct bpos *search,
1333                                 struct bkey_packed *packed_search,
1334                                 const struct bkey_packed *lossy_packed_search,
1335                                 struct bkey_packed *m)
1336 {
1337         if (lossy_packed_search)
1338                 while (m != btree_bkey_last(b, t) &&
1339                        bkey_iter_cmp_p_or_unp(b, m,
1340                                         lossy_packed_search, search) < 0)
1341                         m = bkey_next_skip_noops(m, btree_bkey_last(b, t));
1342
1343         if (!packed_search)
1344                 while (m != btree_bkey_last(b, t) &&
1345                        bkey_iter_pos_cmp(b, m, search) < 0)
1346                         m = bkey_next_skip_noops(m, btree_bkey_last(b, t));
1347
1348         if (btree_keys_expensive_checks(b)) {
1349                 struct bkey_packed *prev = bch2_bkey_prev_all(b, t, m);
1350
1351                 BUG_ON(prev &&
1352                        bkey_iter_cmp_p_or_unp(b, prev,
1353                                         packed_search, search) >= 0);
1354         }
1355
1356         return m;
1357 }
1358
1359 /*
1360  * Returns the first key greater than or equal to @search
1361  */
1362 static __always_inline __flatten
1363 struct bkey_packed *bch2_bset_search(struct btree *b,
1364                                 struct bset_tree *t,
1365                                 struct bpos *search,
1366                                 struct bkey_packed *packed_search,
1367                                 const struct bkey_packed *lossy_packed_search)
1368 {
1369         struct bkey_packed *m = __bch2_bset_search(b, t, search,
1370                                                    lossy_packed_search);
1371
1372         return bch2_bset_search_linear(b, t, search,
1373                                  packed_search, lossy_packed_search, m);
1374 }
1375
1376 /* Btree node iterator */
1377
1378 static inline void __bch2_btree_node_iter_push(struct btree_node_iter *iter,
1379                               struct btree *b,
1380                               const struct bkey_packed *k,
1381                               const struct bkey_packed *end)
1382 {
1383         if (k != end) {
1384                 struct btree_node_iter_set *pos;
1385
1386                 btree_node_iter_for_each(iter, pos)
1387                         ;
1388
1389                 BUG_ON(pos >= iter->data + ARRAY_SIZE(iter->data));
1390                 *pos = (struct btree_node_iter_set) {
1391                         __btree_node_key_to_offset(b, k),
1392                         __btree_node_key_to_offset(b, end)
1393                 };
1394         }
1395 }
1396
1397 void bch2_btree_node_iter_push(struct btree_node_iter *iter,
1398                                struct btree *b,
1399                                const struct bkey_packed *k,
1400                                const struct bkey_packed *end)
1401 {
1402         __bch2_btree_node_iter_push(iter, b, k, end);
1403         bch2_btree_node_iter_sort(iter, b);
1404 }
1405
1406 noinline __flatten __attribute__((cold))
1407 static void btree_node_iter_init_pack_failed(struct btree_node_iter *iter,
1408                               struct btree *b, struct bpos *search)
1409 {
1410         struct bset_tree *t;
1411
1412         trace_bkey_pack_pos_fail(search);
1413
1414         for_each_bset(b, t)
1415                 __bch2_btree_node_iter_push(iter, b,
1416                         bch2_bset_search(b, t, search, NULL, NULL),
1417                         btree_bkey_last(b, t));
1418
1419         bch2_btree_node_iter_sort(iter, b);
1420 }
1421
1422 /**
1423  * bch_btree_node_iter_init - initialize a btree node iterator, starting from a
1424  * given position
1425  *
1426  * Main entry point to the lookup code for individual btree nodes:
1427  *
1428  * NOTE:
1429  *
1430  * When you don't filter out deleted keys, btree nodes _do_ contain duplicate
1431  * keys. This doesn't matter for most code, but it does matter for lookups.
1432  *
1433  * Some adjacent keys with a string of equal keys:
1434  *      i j k k k k l m
1435  *
1436  * If you search for k, the lookup code isn't guaranteed to return you any
1437  * specific k. The lookup code is conceptually doing a binary search and
1438  * iterating backwards is very expensive so if the pivot happens to land at the
1439  * last k that's what you'll get.
1440  *
1441  * This works out ok, but it's something to be aware of:
1442  *
1443  *  - For non extents, we guarantee that the live key comes last - see
1444  *    btree_node_iter_cmp(), keys_out_of_order(). So the duplicates you don't
1445  *    see will only be deleted keys you don't care about.
1446  *
1447  *  - For extents, deleted keys sort last (see the comment at the top of this
1448  *    file). But when you're searching for extents, you actually want the first
1449  *    key strictly greater than your search key - an extent that compares equal
1450  *    to the search key is going to have 0 sectors after the search key.
1451  *
1452  *    But this does mean that we can't just search for
1453  *    bkey_successor(start_of_range) to get the first extent that overlaps with
1454  *    the range we want - if we're unlucky and there's an extent that ends
1455  *    exactly where we searched, then there could be a deleted key at the same
1456  *    position and we'd get that when we search instead of the preceding extent
1457  *    we needed.
1458  *
1459  *    So we've got to search for start_of_range, then after the lookup iterate
1460  *    past any extents that compare equal to the position we searched for.
1461  */
1462 __flatten
1463 void bch2_btree_node_iter_init(struct btree_node_iter *iter,
1464                                struct btree *b, struct bpos *search)
1465 {
1466         struct bkey_packed p, *packed_search = NULL;
1467         struct btree_node_iter_set *pos = iter->data;
1468         struct bkey_packed *k[MAX_BSETS];
1469         unsigned i;
1470
1471         EBUG_ON(bkey_cmp(*search, b->data->min_key) < 0);
1472         bset_aux_tree_verify(b);
1473
1474         memset(iter, 0, sizeof(*iter));
1475
1476         switch (bch2_bkey_pack_pos_lossy(&p, *search, b)) {
1477         case BKEY_PACK_POS_EXACT:
1478                 packed_search = &p;
1479                 break;
1480         case BKEY_PACK_POS_SMALLER:
1481                 packed_search = NULL;
1482                 break;
1483         case BKEY_PACK_POS_FAIL:
1484                 btree_node_iter_init_pack_failed(iter, b, search);
1485                 return;
1486         }
1487
1488         for (i = 0; i < b->nsets; i++) {
1489                 k[i] = __bch2_bset_search(b, b->set + i, search, &p);
1490                 prefetch_four_cachelines(k[i]);
1491         }
1492
1493         for (i = 0; i < b->nsets; i++) {
1494                 struct bset_tree *t = b->set + i;
1495                 struct bkey_packed *end = btree_bkey_last(b, t);
1496
1497                 k[i] = bch2_bset_search_linear(b, t, search,
1498                                                packed_search, &p, k[i]);
1499                 if (k[i] != end)
1500                         *pos++ = (struct btree_node_iter_set) {
1501                                 __btree_node_key_to_offset(b, k[i]),
1502                                 __btree_node_key_to_offset(b, end)
1503                         };
1504         }
1505
1506         bch2_btree_node_iter_sort(iter, b);
1507 }
1508
1509 void bch2_btree_node_iter_init_from_start(struct btree_node_iter *iter,
1510                                           struct btree *b)
1511 {
1512         struct bset_tree *t;
1513
1514         memset(iter, 0, sizeof(*iter));
1515
1516         for_each_bset(b, t)
1517                 __bch2_btree_node_iter_push(iter, b,
1518                                            btree_bkey_first(b, t),
1519                                            btree_bkey_last(b, t));
1520         bch2_btree_node_iter_sort(iter, b);
1521 }
1522
1523 struct bkey_packed *bch2_btree_node_iter_bset_pos(struct btree_node_iter *iter,
1524                                                   struct btree *b,
1525                                                   struct bset_tree *t)
1526 {
1527         struct btree_node_iter_set *set;
1528
1529         btree_node_iter_for_each(iter, set)
1530                 if (set->end == t->end_offset)
1531                         return __btree_node_offset_to_key(b, set->k);
1532
1533         return btree_bkey_last(b, t);
1534 }
1535
1536 static inline bool btree_node_iter_sort_two(struct btree_node_iter *iter,
1537                                             struct btree *b,
1538                                             unsigned first)
1539 {
1540         bool ret;
1541
1542         if ((ret = (btree_node_iter_cmp(b,
1543                                         iter->data[first],
1544                                         iter->data[first + 1]) > 0)))
1545                 swap(iter->data[first], iter->data[first + 1]);
1546         return ret;
1547 }
1548
1549 void bch2_btree_node_iter_sort(struct btree_node_iter *iter,
1550                                struct btree *b)
1551 {
1552         /* unrolled bubble sort: */
1553
1554         if (!__btree_node_iter_set_end(iter, 2)) {
1555                 btree_node_iter_sort_two(iter, b, 0);
1556                 btree_node_iter_sort_two(iter, b, 1);
1557         }
1558
1559         if (!__btree_node_iter_set_end(iter, 1))
1560                 btree_node_iter_sort_two(iter, b, 0);
1561 }
1562
1563 void bch2_btree_node_iter_set_drop(struct btree_node_iter *iter,
1564                                    struct btree_node_iter_set *set)
1565 {
1566         struct btree_node_iter_set *last =
1567                 iter->data + ARRAY_SIZE(iter->data) - 1;
1568
1569         memmove(&set[0], &set[1], (void *) last - (void *) set);
1570         *last = (struct btree_node_iter_set) { 0, 0 };
1571 }
1572
1573 static inline void __bch2_btree_node_iter_advance(struct btree_node_iter *iter,
1574                                                   struct btree *b)
1575 {
1576         iter->data->k += __bch2_btree_node_iter_peek_all(iter, b)->u64s;
1577
1578         EBUG_ON(iter->data->k > iter->data->end);
1579
1580         while (!__btree_node_iter_set_end(iter, 0) &&
1581                !__bch2_btree_node_iter_peek_all(iter, b)->u64s)
1582                 iter->data->k++;
1583
1584         if (unlikely(__btree_node_iter_set_end(iter, 0))) {
1585                 bch2_btree_node_iter_set_drop(iter, iter->data);
1586                 return;
1587         }
1588
1589         if (__btree_node_iter_set_end(iter, 1))
1590                 return;
1591
1592         if (!btree_node_iter_sort_two(iter, b, 0))
1593                 return;
1594
1595         if (__btree_node_iter_set_end(iter, 2))
1596                 return;
1597
1598         btree_node_iter_sort_two(iter, b, 1);
1599 }
1600
1601 void bch2_btree_node_iter_advance(struct btree_node_iter *iter,
1602                                   struct btree *b)
1603 {
1604         if (btree_keys_expensive_checks(b)) {
1605                 bch2_btree_node_iter_verify(iter, b);
1606                 bch2_btree_node_iter_next_check(iter, b);
1607         }
1608
1609         __bch2_btree_node_iter_advance(iter, b);
1610 }
1611
1612 /*
1613  * Expensive:
1614  */
1615 struct bkey_packed *bch2_btree_node_iter_prev_all(struct btree_node_iter *iter,
1616                                                   struct btree *b)
1617 {
1618         struct bkey_packed *k, *prev = NULL;
1619         struct btree_node_iter_set *set;
1620         struct bset_tree *t;
1621         unsigned end = 0;
1622
1623         if (btree_keys_expensive_checks(b))
1624                 bch2_btree_node_iter_verify(iter, b);
1625
1626         for_each_bset(b, t) {
1627                 k = bch2_bkey_prev_all(b, t,
1628                         bch2_btree_node_iter_bset_pos(iter, b, t));
1629                 if (k &&
1630                     (!prev || bkey_iter_cmp(b, k, prev) > 0)) {
1631                         prev = k;
1632                         end = t->end_offset;
1633                 }
1634         }
1635
1636         if (!prev)
1637                 return NULL;
1638
1639         /*
1640          * We're manually memmoving instead of just calling sort() to ensure the
1641          * prev we picked ends up in slot 0 - sort won't necessarily put it
1642          * there because of duplicate deleted keys:
1643          */
1644         btree_node_iter_for_each(iter, set)
1645                 if (set->end == end)
1646                         goto found;
1647
1648         BUG_ON(set != &iter->data[__btree_node_iter_used(iter)]);
1649 found:
1650         BUG_ON(set >= iter->data + ARRAY_SIZE(iter->data));
1651
1652         memmove(&iter->data[1],
1653                 &iter->data[0],
1654                 (void *) set - (void *) &iter->data[0]);
1655
1656         iter->data[0].k = __btree_node_key_to_offset(b, prev);
1657         iter->data[0].end = end;
1658
1659         if (btree_keys_expensive_checks(b))
1660                 bch2_btree_node_iter_verify(iter, b);
1661         return prev;
1662 }
1663
1664 struct bkey_packed *bch2_btree_node_iter_prev_filter(struct btree_node_iter *iter,
1665                                                      struct btree *b,
1666                                                      unsigned min_key_type)
1667 {
1668         struct bkey_packed *prev;
1669
1670         do {
1671                 prev = bch2_btree_node_iter_prev_all(iter, b);
1672         } while (prev && prev->type < min_key_type);
1673
1674         return prev;
1675 }
1676
1677 struct bkey_s_c bch2_btree_node_iter_peek_unpack(struct btree_node_iter *iter,
1678                                                  struct btree *b,
1679                                                  struct bkey *u)
1680 {
1681         struct bkey_packed *k = bch2_btree_node_iter_peek(iter, b);
1682
1683         return k ? bkey_disassemble(b, k, u) : bkey_s_c_null;
1684 }
1685
1686 /* Mergesort */
1687
1688 void bch2_btree_keys_stats(struct btree *b, struct bset_stats *stats)
1689 {
1690         struct bset_tree *t;
1691
1692         for_each_bset(b, t) {
1693                 enum bset_aux_tree_type type = bset_aux_tree_type(t);
1694                 size_t j;
1695
1696                 stats->sets[type].nr++;
1697                 stats->sets[type].bytes += le16_to_cpu(bset(b, t)->u64s) *
1698                         sizeof(u64);
1699
1700                 if (bset_has_ro_aux_tree(t)) {
1701                         stats->floats += t->size - 1;
1702
1703                         for (j = 1; j < t->size; j++)
1704                                 stats->failed +=
1705                                         bkey_float(b, t, j)->exponent ==
1706                                         BFLOAT_FAILED;
1707                 }
1708         }
1709 }
1710
1711 void bch2_bfloat_to_text(struct printbuf *out, struct btree *b,
1712                          struct bkey_packed *k)
1713 {
1714         struct bset_tree *t = bch2_bkey_to_bset(b, k);
1715         struct bkey uk;
1716         unsigned j, inorder;
1717
1718         if (out->pos != out->end)
1719                 *out->pos = '\0';
1720
1721         if (!bset_has_ro_aux_tree(t))
1722                 return;
1723
1724         inorder = bkey_to_cacheline(b, t, k);
1725         if (!inorder || inorder >= t->size)
1726                 return;
1727
1728         j = __inorder_to_eytzinger1(inorder, t->size, t->extra);
1729         if (k != tree_to_bkey(b, t, j))
1730                 return;
1731
1732         switch (bkey_float(b, t, j)->exponent) {
1733         case BFLOAT_FAILED:
1734                 uk = bkey_unpack_key(b, k);
1735                 pr_buf(out,
1736                        "    failed unpacked at depth %u\n"
1737                        "\t%llu:%llu\n",
1738                        ilog2(j),
1739                        uk.p.inode, uk.p.offset);
1740                 break;
1741         }
1742 }