git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/btree_iter.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _BCACHEFS_BTREE_ITER_H
   3 #define _BCACHEFS_BTREE_ITER_H
   4
   5 #include "bset.h"
   6 #include "btree_types.h"
   7
   8 #include <trace/events/bcachefs.h>
   9
  10 static inline void __btree_path_get(struct btree_path *path, bool intent)
  11 {
  12         path->ref++;
  13         path->intent_ref += intent;
  14 }
  15
  16 static inline bool __btree_path_put(struct btree_path *path, bool intent)
  17 {
  18         EBUG_ON(!path->ref);
  19         EBUG_ON(!path->intent_ref && intent);
  20         path->intent_ref -= intent;
  21         return --path->ref == 0;
  22 }
  23
  24 static inline void btree_path_set_dirty(struct btree_path *path,
  25                                         enum btree_path_uptodate u)
  26 {
  27         path->uptodate = max_t(unsigned, path->uptodate, u);
  28 }
  29
  30 static inline struct btree *btree_path_node(struct btree_path *path,
  31                                             unsigned level)
  32 {
  33         return level < BTREE_MAX_DEPTH ? path->l[level].b : NULL;
  34 }
  35
  36 static inline bool btree_node_lock_seq_matches(const struct btree_path *path,
  37                                         const struct btree *b, unsigned level)
  38 {
  39         /*
  40          * We don't compare the low bits of the lock sequence numbers because
  41          * @path might have taken a write lock on @b, and we don't want to skip
  42          * the linked path if the sequence numbers were equal before taking that
  43          * write lock. The lock sequence number is incremented by taking and
  44          * releasing write locks and is even when unlocked:
  45          */
  46         return path->l[level].lock_seq >> 1 == b->c.lock.state.seq >> 1;
  47 }
  48
  49 static inline struct btree *btree_node_parent(struct btree_path *path,
  50                                               struct btree *b)
  51 {
  52         return btree_path_node(path, b->c.level + 1);
  53 }
  54
  55 /* Iterate over paths within a transaction: */
  56
  57 void __bch2_btree_trans_sort_paths(struct btree_trans *);
  58
  59 static inline void btree_trans_sort_paths(struct btree_trans *trans)
  60 {
  61         if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
  62             trans->paths_sorted)
  63                 return;
  64         __bch2_btree_trans_sort_paths(trans);
  65 }
  66
  67 static inline struct btree_path *
  68 __trans_next_path(struct btree_trans *trans, unsigned idx)
  69 {
  70         u64 l;
  71
  72         if (idx == BTREE_ITER_MAX)
  73                 return NULL;
  74
  75         l = trans->paths_allocated >> idx;
  76         if (!l)
  77                 return NULL;
  78
  79         idx += __ffs64(l);
  80         EBUG_ON(idx >= BTREE_ITER_MAX);
  81         EBUG_ON(trans->paths[idx].idx != idx);
  82         return &trans->paths[idx];
  83 }
  84
  85 #define trans_for_each_path_from(_trans, _path, _start)                 \
  86         for (_path = __trans_next_path((_trans), _start);               \
  87              (_path);                                                   \
  88              _path = __trans_next_path((_trans), (_path)->idx + 1))
  89
  90 #define trans_for_each_path(_trans, _path)                              \
  91         trans_for_each_path_from(_trans, _path, 0)
  92
  93 static inline struct btree_path *next_btree_path(struct btree_trans *trans, struct btree_path *path)
  94 {
  95         unsigned idx = path ? path->sorted_idx + 1 : 0;
  96
  97         EBUG_ON(idx > trans->nr_sorted);
  98
  99         return idx < trans->nr_sorted
 100                 ? trans->paths + trans->sorted[idx]
 101                 : NULL;
 102 }
 103
 104 static inline struct btree_path *prev_btree_path(struct btree_trans *trans, struct btree_path *path)
 105 {
 106         unsigned idx = path ? path->sorted_idx : trans->nr_sorted;
 107
 108         return idx
 109                 ? trans->paths + trans->sorted[idx - 1]
 110                 : NULL;
 111 }
 112
 113 #define trans_for_each_path_inorder(_trans, _path, _i)                  \
 114         for (_i = 0;                                                    \
 115              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) < (_trans)->nr_sorted;\
 116              _i++)
 117
 118 #define trans_for_each_path_inorder_reverse(_trans, _path, _i)          \
 119         for (_i = trans->nr_sorted - 1;                                 \
 120              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) >= 0;\
 121              --_i)
 122
 123 static inline bool __path_has_node(const struct btree_path *path,
 124                                    const struct btree *b)
 125 {
 126         return path->l[b->c.level].b == b &&
 127                 btree_node_lock_seq_matches(path, b, b->c.level);
 128 }
 129
 130 static inline struct btree_path *
 131 __trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
 132                             unsigned idx)
 133 {
 134         struct btree_path *path = __trans_next_path(trans, idx);
 135
 136         while (path && !__path_has_node(path, b))
 137                 path = __trans_next_path(trans, path->idx + 1);
 138
 139         return path;
 140 }
 141
 142 #define trans_for_each_path_with_node(_trans, _b, _path)                \
 143         for (_path = __trans_next_path_with_node((_trans), (_b), 0);    \
 144              (_path);                                                   \
 145              _path = __trans_next_path_with_node((_trans), (_b),        \
 146                                                  (_path)->idx + 1))
 147
 148 struct btree_path *__bch2_btree_path_make_mut(struct btree_trans *, struct btree_path *,
 149                          bool, unsigned long);
 150
 151 static inline struct btree_path * __must_check
 152 bch2_btree_path_make_mut(struct btree_trans *trans,
 153                          struct btree_path *path, bool intent,
 154                          unsigned long ip)
 155 {
 156         if (path->ref > 1 || path->preserve)
 157                 path = __bch2_btree_path_make_mut(trans, path, intent, ip);
 158         path->should_be_locked = false;
 159         return path;
 160 }
 161
 162 struct btree_path * __must_check
 163 __bch2_btree_path_set_pos(struct btree_trans *, struct btree_path *,
 164                         struct bpos, bool, unsigned long, int);
 165
 166 static inline struct btree_path * __must_check
 167 bch2_btree_path_set_pos(struct btree_trans *trans,
 168                    struct btree_path *path, struct bpos new_pos,
 169                    bool intent, unsigned long ip)
 170 {
 171         int cmp = bpos_cmp(new_pos, path->pos);
 172
 173         return cmp
 174                 ? __bch2_btree_path_set_pos(trans, path, new_pos, intent, ip, cmp)
 175                 : path;
 176 }
 177
 178 int __must_check bch2_btree_path_traverse_one(struct btree_trans *, struct btree_path *,
 179                                               unsigned, unsigned long);
 180
 181 static inline int __must_check bch2_btree_path_traverse(struct btree_trans *trans,
 182                                           struct btree_path *path, unsigned flags)
 183 {
 184         if (path->uptodate < BTREE_ITER_NEED_RELOCK)
 185                 return 0;
 186
 187         return bch2_btree_path_traverse_one(trans, path, flags, _RET_IP_);
 188 }
 189
 190 int __must_check bch2_btree_path_traverse(struct btree_trans *,
 191                                           struct btree_path *, unsigned);
 192 struct btree_path *bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
 193                                  unsigned, unsigned, unsigned, unsigned long);
 194 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 195
 196 struct bkey_i *bch2_btree_journal_peek_slot(struct btree_trans *,
 197                                         struct btree_iter *, struct bpos);
 198
 199 void bch2_btree_path_level_init(struct btree_trans *, struct btree_path *, struct btree *);
 200
 201 #ifdef CONFIG_BCACHEFS_DEBUG
 202 void bch2_trans_verify_paths(struct btree_trans *);
 203 void bch2_assert_pos_locked(struct btree_trans *, enum btree_id,
 204                             struct bpos, bool);
 205 #else
 206 static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
 207 static inline void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
 208                                           struct bpos pos, bool key_cache) {}
 209 #endif
 210
 211 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
 212                                       struct btree *, struct bkey_packed *);
 213 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
 214                               struct btree *, struct btree_node_iter *,
 215                               struct bkey_packed *, unsigned, unsigned);
 216
 217 int bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);
 218
 219 void bch2_path_put(struct btree_trans *, struct btree_path *, bool);
 220
 221 int bch2_trans_relock(struct btree_trans *);
 222 int bch2_trans_relock_notrace(struct btree_trans *);
 223 void bch2_trans_unlock(struct btree_trans *);
 224 bool bch2_trans_locked(struct btree_trans *);
 225
 226 static inline bool trans_was_restarted(struct btree_trans *trans, u32 restart_count)
 227 {
 228         return restart_count != trans->restart_count;
 229 }
 230
 231 void bch2_trans_restart_error(struct btree_trans *, u32);
 232
 233 static inline void bch2_trans_verify_not_restarted(struct btree_trans *trans,
 234                                                    u32 restart_count)
 235 {
 236         if (trans_was_restarted(trans, restart_count))
 237                 bch2_trans_restart_error(trans, restart_count);
 238 }
 239
 240 void bch2_trans_in_restart_error(struct btree_trans *);
 241
 242 static inline void bch2_trans_verify_not_in_restart(struct btree_trans *trans)
 243 {
 244         if (trans->restarted)
 245                 bch2_trans_in_restart_error(trans);
 246 }
 247
 248 __always_inline
 249 static inline int btree_trans_restart_nounlock(struct btree_trans *trans, int err)
 250 {
 251         BUG_ON(err <= 0);
 252         BUG_ON(!bch2_err_matches(err, BCH_ERR_transaction_restart));
 253
 254         trans->restarted = err;
 255         return -err;
 256 }
 257
 258 __always_inline
 259 static inline int btree_trans_restart(struct btree_trans *trans, int err)
 260 {
 261         btree_trans_restart_nounlock(trans, err);
 262         return -err;
 263 }
 264
 265 bool bch2_btree_node_upgrade(struct btree_trans *,
 266                              struct btree_path *, unsigned);
 267
 268 void __bch2_btree_path_downgrade(struct btree_trans *, struct btree_path *, unsigned);
 269
 270 static inline void bch2_btree_path_downgrade(struct btree_trans *trans,
 271                                              struct btree_path *path)
 272 {
 273         unsigned new_locks_want = path->level + !!path->intent_ref;
 274
 275         if (path->locks_want > new_locks_want)
 276                 __bch2_btree_path_downgrade(trans, path, new_locks_want);
 277 }
 278
 279 void bch2_trans_downgrade(struct btree_trans *);
 280
 281 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
 282 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 283
 284 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
 285 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 286
 287 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 288 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 289
 290 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *, struct bpos);
 291 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 292
 293 struct bkey_s_c bch2_btree_iter_peek_all_levels(struct btree_iter *);
 294
 295 static inline struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
 296 {
 297         return bch2_btree_iter_peek_upto(iter, SPOS_MAX);
 298 }
 299
 300 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 301 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 302
 303 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 304 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 305 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 306
 307 bool bch2_btree_iter_advance(struct btree_iter *);
 308 bool bch2_btree_iter_rewind(struct btree_iter *);
 309
 310 static inline void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 311 {
 312         iter->k.type = KEY_TYPE_deleted;
 313         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 314         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 315         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 316         iter->k.size = 0;
 317 }
 318
 319 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 320 {
 321         if (unlikely(iter->update_path))
 322                 bch2_path_put(iter->trans, iter->update_path,
 323                               iter->flags & BTREE_ITER_INTENT);
 324         iter->update_path = NULL;
 325
 326         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 327                 new_pos.snapshot = iter->snapshot;
 328
 329         __bch2_btree_iter_set_pos(iter, new_pos);
 330 }
 331
 332 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 333 {
 334         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 335         iter->pos = bkey_start_pos(&iter->k);
 336 }
 337
 338 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 339 {
 340         struct bpos pos = iter->pos;
 341
 342         iter->snapshot = snapshot;
 343         pos.snapshot = snapshot;
 344         bch2_btree_iter_set_pos(iter, pos);
 345 }
 346
 347 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 348
 349 static inline unsigned __bch2_btree_iter_flags(struct btree_trans *trans,
 350                                                unsigned btree_id,
 351                                                unsigned flags)
 352 {
 353         if (flags & BTREE_ITER_ALL_LEVELS)
 354                 flags |= BTREE_ITER_ALL_SNAPSHOTS|__BTREE_ITER_ALL_SNAPSHOTS;
 355
 356         if (!(flags & (BTREE_ITER_ALL_SNAPSHOTS|BTREE_ITER_NOT_EXTENTS)) &&
 357             btree_node_type_is_extents(btree_id))
 358                 flags |= BTREE_ITER_IS_EXTENTS;
 359
 360         if (!(flags & __BTREE_ITER_ALL_SNAPSHOTS) &&
 361             !btree_type_has_snapshots(btree_id))
 362                 flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
 363
 364         if (!(flags & BTREE_ITER_ALL_SNAPSHOTS) &&
 365             btree_type_has_snapshots(btree_id))
 366                 flags |= BTREE_ITER_FILTER_SNAPSHOTS;
 367
 368         if (trans->journal_replay_not_finished)
 369                 flags |= BTREE_ITER_WITH_JOURNAL;
 370
 371         return flags;
 372 }
 373
 374 static inline unsigned bch2_btree_iter_flags(struct btree_trans *trans,
 375                                              unsigned btree_id,
 376                                              unsigned flags)
 377 {
 378         if (!btree_id_cached(trans->c, btree_id)) {
 379                 flags &= ~BTREE_ITER_CACHED;
 380                 flags &= ~BTREE_ITER_WITH_KEY_CACHE;
 381         } else if (!(flags & BTREE_ITER_CACHED))
 382                 flags |= BTREE_ITER_WITH_KEY_CACHE;
 383
 384         return __bch2_btree_iter_flags(trans, btree_id, flags);
 385 }
 386
 387 static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
 388                                           struct btree_iter *iter,
 389                                           unsigned btree_id, struct bpos pos,
 390                                           unsigned locks_want,
 391                                           unsigned depth,
 392                                           unsigned flags,
 393                                           unsigned long ip)
 394 {
 395         memset(iter, 0, sizeof(*iter));
 396         iter->trans     = trans;
 397         iter->btree_id  = btree_id;
 398         iter->flags     = flags;
 399         iter->snapshot  = pos.snapshot;
 400         iter->pos       = pos;
 401         iter->k.p       = pos;
 402
 403 #ifdef CONFIG_BCACHEFS_DEBUG
 404         iter->ip_allocated = ip;
 405 #endif
 406         iter->path = bch2_path_get(trans, btree_id, iter->pos,
 407                                    locks_want, depth, flags, ip);
 408 }
 409
 410 void bch2_trans_iter_init_outlined(struct btree_trans *, struct btree_iter *,
 411                           unsigned, struct bpos, unsigned);
 412
 413 static inline void bch2_trans_iter_init(struct btree_trans *trans,
 414                           struct btree_iter *iter,
 415                           unsigned btree_id, struct bpos pos,
 416                           unsigned flags)
 417 {
 418         if (__builtin_constant_p(btree_id) &&
 419             __builtin_constant_p(flags))
 420                 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
 421                                 bch2_btree_iter_flags(trans, btree_id, flags),
 422                                 _THIS_IP_);
 423         else
 424                 bch2_trans_iter_init_outlined(trans, iter, btree_id, pos, flags);
 425 }
 426
 427 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 428                                enum btree_id, struct bpos,
 429                                unsigned, unsigned, unsigned);
 430 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 431
 432 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 433 {
 434         if (!iter->trans->restarted)
 435                 iter->path->preserve = false;
 436 }
 437
 438 void *__bch2_trans_kmalloc(struct btree_trans *, size_t);
 439
 440 static inline void *bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
 441 {
 442         size = roundup(size, 8);
 443
 444         if (likely(trans->mem_top + size <= trans->mem_bytes)) {
 445                 void *p = trans->mem + trans->mem_top;
 446
 447                 trans->mem_top += size;
 448                 memset(p, 0, size);
 449                 return p;
 450         } else {
 451                 return __bch2_trans_kmalloc(trans, size);
 452         }
 453 }
 454
 455 static inline void *bch2_trans_kmalloc_nomemzero(struct btree_trans *trans, size_t size)
 456 {
 457         size = roundup(size, 8);
 458
 459         if (likely(trans->mem_top + size <= trans->mem_bytes)) {
 460                 void *p = trans->mem + trans->mem_top;
 461
 462                 trans->mem_top += size;
 463                 return p;
 464         } else {
 465                 return __bch2_trans_kmalloc(trans, size);
 466         }
 467 }
 468
 469 static inline struct bkey_i *bch2_bkey_make_mut(struct btree_trans *trans, struct bkey_s_c k)
 470 {
 471         struct bkey_i *mut = bch2_trans_kmalloc_nomemzero(trans, bkey_bytes(k.k));
 472
 473         if (!IS_ERR(mut))
 474                 bkey_reassemble(mut, k);
 475         return mut;
 476 }
 477
 478 static inline struct bkey_i *bch2_bkey_get_mut(struct btree_trans *trans,
 479                                                struct btree_iter *iter)
 480 {
 481         struct bkey_s_c k = bch2_btree_iter_peek_slot(iter);
 482
 483         return unlikely(IS_ERR(k.k))
 484                 ? ERR_CAST(k.k)
 485                 : bch2_bkey_make_mut(trans, k);
 486 }
 487
 488 #define bch2_bkey_get_mut_typed(_trans, _iter, _type)                   \
 489 ({                                                                      \
 490         struct bkey_i *_k = bch2_bkey_get_mut(_trans, _iter);           \
 491         struct bkey_i_##_type *_ret;                                    \
 492                                                                         \
 493         if (IS_ERR(_k))                                                 \
 494                 _ret = ERR_CAST(_k);                                    \
 495         else if (unlikely(_k->k.type != KEY_TYPE_##_type))              \
 496                 _ret = ERR_PTR(-ENOENT);                                \
 497         else                                                            \
 498                 _ret = bkey_i_to_##_type(_k);                           \
 499         _ret;                                                           \
 500 })
 501
 502 #define bch2_bkey_alloc(_trans, _iter, _type)                           \
 503 ({                                                                      \
 504         struct bkey_i_##_type *_k = bch2_trans_kmalloc_nomemzero(_trans, sizeof(*_k));\
 505         if (!IS_ERR(_k)) {                                              \
 506                 bkey_##_type##_init(&_k->k_i);                          \
 507                 _k->k.p = (_iter)->pos;                                 \
 508         }                                                               \
 509         _k;                                                             \
 510 })
 511
 512 u32 bch2_trans_begin(struct btree_trans *);
 513
 514 static inline struct btree *
 515 __btree_iter_peek_node_and_restart(struct btree_trans *trans, struct btree_iter *iter)
 516 {
 517         struct btree *b;
 518
 519         while (b = bch2_btree_iter_peek_node(iter),
 520                bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart))
 521                 bch2_trans_begin(trans);
 522
 523         return b;
 524 }
 525
 526 /*
 527  * XXX
 528  * this does not handle transaction restarts from bch2_btree_iter_next_node()
 529  * correctly
 530  */
 531 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 532                               _locks_want, _depth, _flags, _b, _ret)    \
 533         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 534                                 _start, _locks_want, _depth, _flags);   \
 535              (_b) = __btree_iter_peek_node_and_restart((_trans), &(_iter)),\
 536              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
 537              (_b) = bch2_btree_iter_next_node(&(_iter)))
 538
 539 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 540                             _flags, _b, _ret)                           \
 541         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 542                               0, 0, _flags, _b, _ret)
 543
 544 static inline int bkey_err(struct bkey_s_c k)
 545 {
 546         return PTR_ERR_OR_ZERO(k.k);
 547 }
 548
 549 static inline struct bkey_s_c bch2_btree_iter_peek_prev_type(struct btree_iter *iter,
 550                                                              unsigned flags)
 551 {
 552         BUG_ON(flags & BTREE_ITER_ALL_LEVELS);
 553
 554         return  flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
 555                                                 bch2_btree_iter_peek_prev(iter);
 556 }
 557
 558 static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
 559                                                         unsigned flags)
 560 {
 561         return  flags & BTREE_ITER_ALL_LEVELS ? bch2_btree_iter_peek_all_levels(iter) :
 562                 flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
 563                                                 bch2_btree_iter_peek(iter);
 564 }
 565
 566 static inline struct bkey_s_c bch2_btree_iter_peek_upto_type(struct btree_iter *iter,
 567                                                              struct bpos end,
 568                                                              unsigned flags)
 569 {
 570         if (!(flags & BTREE_ITER_SLOTS))
 571                 return bch2_btree_iter_peek_upto(iter, end);
 572
 573         if (bkey_gt(iter->pos, end))
 574                 return bkey_s_c_null;
 575
 576         return bch2_btree_iter_peek_slot(iter);
 577 }
 578
 579 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
 580 {
 581         if (hweight64(trans->paths_allocated) > BTREE_ITER_MAX - 8) {
 582                 trace_and_count(trans->c, trans_restart_too_many_iters, trans, _THIS_IP_);
 583                 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters);
 584         }
 585
 586         return 0;
 587 }
 588
 589 static inline struct bkey_s_c
 590 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 591                                    struct btree_iter *iter, unsigned flags)
 592 {
 593         struct bkey_s_c k;
 594
 595         while (btree_trans_too_many_iters(trans) ||
 596                (k = bch2_btree_iter_peek_type(iter, flags),
 597                 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
 598                 bch2_trans_begin(trans);
 599
 600         return k;
 601 }
 602
 603 static inline struct bkey_s_c
 604 __bch2_btree_iter_peek_upto_and_restart(struct btree_trans *trans,
 605                                         struct btree_iter *iter,
 606                                         struct bpos end,
 607                                         unsigned flags)
 608 {
 609         struct bkey_s_c k;
 610
 611         while (btree_trans_too_many_iters(trans) ||
 612                (k = bch2_btree_iter_peek_upto_type(iter, end, flags),
 613                 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
 614                 bch2_trans_begin(trans);
 615
 616         return k;
 617 }
 618
 619 #define lockrestart_do(_trans, _do)                                     \
 620 ({                                                                      \
 621         u32 _restart_count;                                             \
 622         int _ret;                                                       \
 623                                                                         \
 624         do {                                                            \
 625                 _restart_count = bch2_trans_begin(_trans);              \
 626                 _ret = (_do);                                           \
 627         } while (bch2_err_matches(_ret, BCH_ERR_transaction_restart));  \
 628                                                                         \
 629         if (!_ret)                                                      \
 630                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 631                                                                         \
 632         _ret;                                                           \
 633 })
 634
 635 /*
 636  * nested_lockrestart_do(), nested_commit_do():
 637  *
 638  * These are like lockrestart_do() and commit_do(), with two differences:
 639  *
 640  *  - We don't call bch2_trans_begin() unless we had a transaction restart
 641  *  - We return -BCH_ERR_transaction_restart_nested if we succeeded after a
 642  *  transaction restart
 643  */
 644 #define nested_lockrestart_do(_trans, _do)                              \
 645 ({                                                                      \
 646         u32 _restart_count, _orig_restart_count;                        \
 647         int _ret;                                                       \
 648                                                                         \
 649         _restart_count = _orig_restart_count = (_trans)->restart_count; \
 650                                                                         \
 651         while (bch2_err_matches(_ret = (_do), BCH_ERR_transaction_restart))\
 652                 _restart_count = bch2_trans_begin(_trans);              \
 653                                                                         \
 654         if (!_ret)                                                      \
 655                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 656                                                                         \
 657         if (!_ret && trans_was_restarted(_trans, _orig_restart_count))  \
 658                 _ret = -BCH_ERR_transaction_restart_nested;             \
 659                                                                         \
 660         _ret;                                                           \
 661 })
 662
 663 #define for_each_btree_key2(_trans, _iter, _btree_id,                   \
 664                             _start, _flags, _k, _do)                    \
 665 ({                                                                      \
 666         int _ret = 0;                                                   \
 667                                                                         \
 668         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 669                              (_start), (_flags));                       \
 670                                                                         \
 671         while (1) {                                                     \
 672                 u32 _restart_count = bch2_trans_begin(_trans);          \
 673                                                                         \
 674                 _ret = 0;                                               \
 675                 (_k) = bch2_btree_iter_peek_type(&(_iter), (_flags));   \
 676                 if (!(_k).k)                                            \
 677                         break;                                          \
 678                                                                         \
 679                 _ret = bkey_err(_k) ?: (_do);                           \
 680                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 681                         continue;                                       \
 682                 if (_ret)                                               \
 683                         break;                                          \
 684                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 685                 if (!bch2_btree_iter_advance(&(_iter)))                 \
 686                         break;                                          \
 687         }                                                               \
 688                                                                         \
 689         bch2_trans_iter_exit((_trans), &(_iter));                       \
 690         _ret;                                                           \
 691 })
 692
 693 #define for_each_btree_key2_upto(_trans, _iter, _btree_id,              \
 694                             _start, _end, _flags, _k, _do)              \
 695 ({                                                                      \
 696         int _ret = 0;                                                   \
 697                                                                         \
 698         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 699                              (_start), (_flags));                       \
 700                                                                         \
 701         while (1) {                                                     \
 702                 u32 _restart_count = bch2_trans_begin(_trans);          \
 703                                                                         \
 704                 _ret = 0;                                               \
 705                 (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, (_flags));\
 706                 if (!(_k).k)                                            \
 707                         break;                                          \
 708                                                                         \
 709                 _ret = bkey_err(_k) ?: (_do);                           \
 710                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 711                         continue;                                       \
 712                 if (_ret)                                               \
 713                         break;                                          \
 714                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 715                 if (!bch2_btree_iter_advance(&(_iter)))                 \
 716                         break;                                          \
 717         }                                                               \
 718                                                                         \
 719         bch2_trans_iter_exit((_trans), &(_iter));                       \
 720         _ret;                                                           \
 721 })
 722
 723 #define for_each_btree_key_reverse(_trans, _iter, _btree_id,            \
 724                                    _start, _flags, _k, _do)             \
 725 ({                                                                      \
 726         int _ret = 0;                                                   \
 727                                                                         \
 728         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 729                              (_start), (_flags));                       \
 730                                                                         \
 731         while (1) {                                                     \
 732                 u32 _restart_count = bch2_trans_begin(_trans);          \
 733                 (_k) = bch2_btree_iter_peek_prev_type(&(_iter), (_flags));\
 734                 if (!(_k).k) {                                          \
 735                         _ret = 0;                                       \
 736                         break;                                          \
 737                 }                                                       \
 738                                                                         \
 739                 _ret = bkey_err(_k) ?: (_do);                           \
 740                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 741                         continue;                                       \
 742                 if (_ret)                                               \
 743                         break;                                          \
 744                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 745                 if (!bch2_btree_iter_rewind(&(_iter)))                  \
 746                         break;                                          \
 747         }                                                               \
 748                                                                         \
 749         bch2_trans_iter_exit((_trans), &(_iter));                       \
 750         _ret;                                                           \
 751 })
 752
 753 #define for_each_btree_key_commit(_trans, _iter, _btree_id,             \
 754                                   _start, _iter_flags, _k,              \
 755                                   _disk_res, _journal_seq, _commit_flags,\
 756                                   _do)                                  \
 757         for_each_btree_key2(_trans, _iter, _btree_id, _start, _iter_flags, _k,\
 758                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 759                                         (_journal_seq), (_commit_flags)))
 760
 761 #define for_each_btree_key_upto_commit(_trans, _iter, _btree_id,        \
 762                                   _start, _end, _iter_flags, _k,        \
 763                                   _disk_res, _journal_seq, _commit_flags,\
 764                                   _do)                                  \
 765         for_each_btree_key2_upto(_trans, _iter, _btree_id, _start, _end, _iter_flags, _k,\
 766                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 767                                         (_journal_seq), (_commit_flags)))
 768
 769 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 770                            _start, _flags, _k, _ret)                    \
 771         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 772                                   (_start), (_flags));                  \
 773              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 774              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 775              bch2_btree_iter_advance(&(_iter)))
 776
 777 #define for_each_btree_key_upto(_trans, _iter, _btree_id,               \
 778                                 _start, _end, _flags, _k, _ret)         \
 779         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 780                                   (_start), (_flags));                  \
 781              (_k) = __bch2_btree_iter_peek_upto_and_restart((_trans),   \
 782                                                 &(_iter), _end, _flags),\
 783              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 784              bch2_btree_iter_advance(&(_iter)))
 785
 786 #define for_each_btree_key_norestart(_trans, _iter, _btree_id,          \
 787                            _start, _flags, _k, _ret)                    \
 788         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 789                                   (_start), (_flags));                  \
 790              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 791              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 792              bch2_btree_iter_advance(&(_iter)))
 793
 794 #define for_each_btree_key_upto_norestart(_trans, _iter, _btree_id,     \
 795                            _start, _end, _flags, _k, _ret)              \
 796         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 797                                   (_start), (_flags));                  \
 798              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),\
 799              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 800              bch2_btree_iter_advance(&(_iter)))
 801
 802 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _ret)    \
 803         for (;                                                          \
 804              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 805              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 806              bch2_btree_iter_advance(&(_iter)))
 807
 808 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
 809         for (;                                                          \
 810              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 811              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 812              bch2_btree_iter_advance(&(_iter)))
 813
 814 #define for_each_btree_key_upto_continue_norestart(_iter, _end, _flags, _k, _ret)\
 815         for (;                                                                  \
 816              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),     \
 817              !((_ret) = bkey_err(_k)) && (_k).k;                                \
 818              bch2_btree_iter_advance(&(_iter)))
 819
 820 /* new multiple iterator interface: */
 821
 822 void bch2_trans_updates_to_text(struct printbuf *, struct btree_trans *);
 823 void bch2_btree_path_to_text(struct printbuf *, struct btree_path *);
 824 void bch2_trans_paths_to_text(struct printbuf *, struct btree_trans *);
 825 void bch2_dump_trans_updates(struct btree_trans *);
 826 void bch2_dump_trans_paths_updates(struct btree_trans *);
 827 void __bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned);
 828 void bch2_trans_exit(struct btree_trans *);
 829
 830 extern const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR];
 831 unsigned bch2_trans_get_fn_idx(const char *);
 832
 833 #define bch2_trans_init(_trans, _c, _nr_iters, _mem)                    \
 834 do {                                                                    \
 835         static unsigned trans_fn_idx;                                   \
 836                                                                         \
 837         if (unlikely(!trans_fn_idx))                                    \
 838                 trans_fn_idx = bch2_trans_get_fn_idx(__func__);         \
 839                                                                         \
 840         __bch2_trans_init(_trans, _c, trans_fn_idx);                    \
 841 } while (0)
 842
 843 void bch2_btree_trans_to_text(struct printbuf *, struct btree_trans *);
 844
 845 void bch2_fs_btree_iter_exit(struct bch_fs *);
 846 int bch2_fs_btree_iter_init(struct bch_fs *);
 847
 848 #endif /* _BCACHEFS_BTREE_ITER_H */