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 #ifdef CONFIG_BCACHEFS_DEBUG
 255         bch2_save_backtrace(&trans->last_restarted, current);
 256 #endif
 257
 258         trans->restarted = err;
 259         return -err;
 260 }
 261
 262 __always_inline
 263 static inline int btree_trans_restart(struct btree_trans *trans, int err)
 264 {
 265         btree_trans_restart_nounlock(trans, err);
 266         return -err;
 267 }
 268
 269 bool bch2_btree_node_upgrade(struct btree_trans *,
 270                              struct btree_path *, unsigned);
 271
 272 void __bch2_btree_path_downgrade(struct btree_trans *, struct btree_path *, unsigned);
 273
 274 static inline void bch2_btree_path_downgrade(struct btree_trans *trans,
 275                                              struct btree_path *path)
 276 {
 277         unsigned new_locks_want = path->level + !!path->intent_ref;
 278
 279         if (path->locks_want > new_locks_want)
 280                 __bch2_btree_path_downgrade(trans, path, new_locks_want);
 281 }
 282
 283 void bch2_trans_downgrade(struct btree_trans *);
 284
 285 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
 286 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 287
 288 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
 289 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 290
 291 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 292 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 293
 294 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *, struct bpos);
 295 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 296
 297 struct bkey_s_c bch2_btree_iter_peek_all_levels(struct btree_iter *);
 298
 299 static inline struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
 300 {
 301         return bch2_btree_iter_peek_upto(iter, SPOS_MAX);
 302 }
 303
 304 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 305 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 306
 307 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 308 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 309 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 310
 311 bool bch2_btree_iter_advance(struct btree_iter *);
 312 bool bch2_btree_iter_rewind(struct btree_iter *);
 313
 314 static inline void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 315 {
 316         iter->k.type = KEY_TYPE_deleted;
 317         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 318         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 319         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 320         iter->k.size = 0;
 321 }
 322
 323 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 324 {
 325         if (unlikely(iter->update_path))
 326                 bch2_path_put(iter->trans, iter->update_path,
 327                               iter->flags & BTREE_ITER_INTENT);
 328         iter->update_path = NULL;
 329
 330         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 331                 new_pos.snapshot = iter->snapshot;
 332
 333         __bch2_btree_iter_set_pos(iter, new_pos);
 334 }
 335
 336 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 337 {
 338         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 339         iter->pos = bkey_start_pos(&iter->k);
 340 }
 341
 342 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 343 {
 344         struct bpos pos = iter->pos;
 345
 346         iter->snapshot = snapshot;
 347         pos.snapshot = snapshot;
 348         bch2_btree_iter_set_pos(iter, pos);
 349 }
 350
 351 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 352
 353 static inline unsigned __bch2_btree_iter_flags(struct btree_trans *trans,
 354                                                unsigned btree_id,
 355                                                unsigned flags)
 356 {
 357         if (flags & BTREE_ITER_ALL_LEVELS)
 358                 flags |= BTREE_ITER_ALL_SNAPSHOTS|__BTREE_ITER_ALL_SNAPSHOTS;
 359
 360         if (!(flags & (BTREE_ITER_ALL_SNAPSHOTS|BTREE_ITER_NOT_EXTENTS)) &&
 361             btree_node_type_is_extents(btree_id))
 362                 flags |= BTREE_ITER_IS_EXTENTS;
 363
 364         if (!(flags & __BTREE_ITER_ALL_SNAPSHOTS) &&
 365             !btree_type_has_snapshots(btree_id))
 366                 flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
 367
 368         if (!(flags & BTREE_ITER_ALL_SNAPSHOTS) &&
 369             btree_type_has_snapshots(btree_id))
 370                 flags |= BTREE_ITER_FILTER_SNAPSHOTS;
 371
 372         if (trans->journal_replay_not_finished)
 373                 flags |= BTREE_ITER_WITH_JOURNAL;
 374
 375         return flags;
 376 }
 377
 378 static inline unsigned bch2_btree_iter_flags(struct btree_trans *trans,
 379                                              unsigned btree_id,
 380                                              unsigned flags)
 381 {
 382         if (!btree_id_cached(trans->c, btree_id)) {
 383                 flags &= ~BTREE_ITER_CACHED;
 384                 flags &= ~BTREE_ITER_WITH_KEY_CACHE;
 385         } else if (!(flags & BTREE_ITER_CACHED))
 386                 flags |= BTREE_ITER_WITH_KEY_CACHE;
 387
 388         return __bch2_btree_iter_flags(trans, btree_id, flags);
 389 }
 390
 391 static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
 392                                           struct btree_iter *iter,
 393                                           unsigned btree_id, struct bpos pos,
 394                                           unsigned locks_want,
 395                                           unsigned depth,
 396                                           unsigned flags,
 397                                           unsigned long ip)
 398 {
 399         memset(iter, 0, sizeof(*iter));
 400         iter->trans     = trans;
 401         iter->btree_id  = btree_id;
 402         iter->flags     = flags;
 403         iter->snapshot  = pos.snapshot;
 404         iter->pos       = pos;
 405         iter->k.p       = pos;
 406
 407 #ifdef CONFIG_BCACHEFS_DEBUG
 408         iter->ip_allocated = ip;
 409 #endif
 410         iter->path = bch2_path_get(trans, btree_id, iter->pos,
 411                                    locks_want, depth, flags, ip);
 412 }
 413
 414 void bch2_trans_iter_init_outlined(struct btree_trans *, struct btree_iter *,
 415                           unsigned, struct bpos, unsigned);
 416
 417 static inline void bch2_trans_iter_init(struct btree_trans *trans,
 418                           struct btree_iter *iter,
 419                           unsigned btree_id, struct bpos pos,
 420                           unsigned flags)
 421 {
 422         if (__builtin_constant_p(btree_id) &&
 423             __builtin_constant_p(flags))
 424                 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
 425                                 bch2_btree_iter_flags(trans, btree_id, flags),
 426                                 _THIS_IP_);
 427         else
 428                 bch2_trans_iter_init_outlined(trans, iter, btree_id, pos, flags);
 429 }
 430
 431 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 432                                enum btree_id, struct bpos,
 433                                unsigned, unsigned, unsigned);
 434 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 435
 436 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 437 {
 438         if (!iter->trans->restarted)
 439                 iter->path->preserve = false;
 440 }
 441
 442 void *__bch2_trans_kmalloc(struct btree_trans *, size_t);
 443
 444 static inline void *bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
 445 {
 446         size = roundup(size, 8);
 447
 448         if (likely(trans->mem_top + size <= trans->mem_bytes)) {
 449                 void *p = trans->mem + trans->mem_top;
 450
 451                 trans->mem_top += size;
 452                 memset(p, 0, size);
 453                 return p;
 454         } else {
 455                 return __bch2_trans_kmalloc(trans, size);
 456         }
 457 }
 458
 459 static inline void *bch2_trans_kmalloc_nomemzero(struct btree_trans *trans, size_t size)
 460 {
 461         size = roundup(size, 8);
 462
 463         if (likely(trans->mem_top + size <= trans->mem_bytes)) {
 464                 void *p = trans->mem + trans->mem_top;
 465
 466                 trans->mem_top += size;
 467                 return p;
 468         } else {
 469                 return __bch2_trans_kmalloc(trans, size);
 470         }
 471 }
 472
 473 static inline struct bkey_i *bch2_bkey_make_mut(struct btree_trans *trans, struct bkey_s_c k)
 474 {
 475         struct bkey_i *mut = bch2_trans_kmalloc_nomemzero(trans, bkey_bytes(k.k));
 476
 477         if (!IS_ERR(mut))
 478                 bkey_reassemble(mut, k);
 479         return mut;
 480 }
 481
 482 static inline struct bkey_i *bch2_bkey_get_mut(struct btree_trans *trans,
 483                                                struct btree_iter *iter)
 484 {
 485         struct bkey_s_c k = bch2_btree_iter_peek_slot(iter);
 486
 487         return unlikely(IS_ERR(k.k))
 488                 ? ERR_CAST(k.k)
 489                 : bch2_bkey_make_mut(trans, k);
 490 }
 491
 492 #define bch2_bkey_get_mut_typed(_trans, _iter, _type)                   \
 493 ({                                                                      \
 494         struct bkey_i *_k = bch2_bkey_get_mut(_trans, _iter);           \
 495         struct bkey_i_##_type *_ret;                                    \
 496                                                                         \
 497         if (IS_ERR(_k))                                                 \
 498                 _ret = ERR_CAST(_k);                                    \
 499         else if (unlikely(_k->k.type != KEY_TYPE_##_type))              \
 500                 _ret = ERR_PTR(-ENOENT);                                \
 501         else                                                            \
 502                 _ret = bkey_i_to_##_type(_k);                           \
 503         _ret;                                                           \
 504 })
 505
 506 #define bch2_bkey_alloc(_trans, _iter, _type)                           \
 507 ({                                                                      \
 508         struct bkey_i_##_type *_k = bch2_trans_kmalloc_nomemzero(_trans, sizeof(*_k));\
 509         if (!IS_ERR(_k)) {                                              \
 510                 bkey_##_type##_init(&_k->k_i);                          \
 511                 _k->k.p = (_iter)->pos;                                 \
 512         }                                                               \
 513         _k;                                                             \
 514 })
 515
 516 u32 bch2_trans_begin(struct btree_trans *);
 517
 518 static inline struct btree *
 519 __btree_iter_peek_node_and_restart(struct btree_trans *trans, struct btree_iter *iter)
 520 {
 521         struct btree *b;
 522
 523         while (b = bch2_btree_iter_peek_node(iter),
 524                bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart))
 525                 bch2_trans_begin(trans);
 526
 527         return b;
 528 }
 529
 530 /*
 531  * XXX
 532  * this does not handle transaction restarts from bch2_btree_iter_next_node()
 533  * correctly
 534  */
 535 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 536                               _locks_want, _depth, _flags, _b, _ret)    \
 537         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 538                                 _start, _locks_want, _depth, _flags);   \
 539              (_b) = __btree_iter_peek_node_and_restart((_trans), &(_iter)),\
 540              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
 541              (_b) = bch2_btree_iter_next_node(&(_iter)))
 542
 543 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 544                             _flags, _b, _ret)                           \
 545         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 546                               0, 0, _flags, _b, _ret)
 547
 548 static inline int bkey_err(struct bkey_s_c k)
 549 {
 550         return PTR_ERR_OR_ZERO(k.k);
 551 }
 552
 553 static inline struct bkey_s_c bch2_btree_iter_peek_prev_type(struct btree_iter *iter,
 554                                                              unsigned flags)
 555 {
 556         BUG_ON(flags & BTREE_ITER_ALL_LEVELS);
 557
 558         return  flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
 559                                                 bch2_btree_iter_peek_prev(iter);
 560 }
 561
 562 static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
 563                                                         unsigned flags)
 564 {
 565         return  flags & BTREE_ITER_ALL_LEVELS ? bch2_btree_iter_peek_all_levels(iter) :
 566                 flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
 567                                                 bch2_btree_iter_peek(iter);
 568 }
 569
 570 static inline struct bkey_s_c bch2_btree_iter_peek_upto_type(struct btree_iter *iter,
 571                                                              struct bpos end,
 572                                                              unsigned flags)
 573 {
 574         if (!(flags & BTREE_ITER_SLOTS))
 575                 return bch2_btree_iter_peek_upto(iter, end);
 576
 577         if (bkey_gt(iter->pos, end))
 578                 return bkey_s_c_null;
 579
 580         return bch2_btree_iter_peek_slot(iter);
 581 }
 582
 583 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
 584 {
 585         if (hweight64(trans->paths_allocated) > BTREE_ITER_MAX - 8) {
 586                 trace_and_count(trans->c, trans_restart_too_many_iters, trans, _THIS_IP_);
 587                 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters);
 588         }
 589
 590         return 0;
 591 }
 592
 593 static inline struct bkey_s_c
 594 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 595                                    struct btree_iter *iter, unsigned flags)
 596 {
 597         struct bkey_s_c k;
 598
 599         while (btree_trans_too_many_iters(trans) ||
 600                (k = bch2_btree_iter_peek_type(iter, flags),
 601                 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
 602                 bch2_trans_begin(trans);
 603
 604         return k;
 605 }
 606
 607 static inline struct bkey_s_c
 608 __bch2_btree_iter_peek_upto_and_restart(struct btree_trans *trans,
 609                                         struct btree_iter *iter,
 610                                         struct bpos end,
 611                                         unsigned flags)
 612 {
 613         struct bkey_s_c k;
 614
 615         while (btree_trans_too_many_iters(trans) ||
 616                (k = bch2_btree_iter_peek_upto_type(iter, end, flags),
 617                 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
 618                 bch2_trans_begin(trans);
 619
 620         return k;
 621 }
 622
 623 #define lockrestart_do(_trans, _do)                                     \
 624 ({                                                                      \
 625         u32 _restart_count;                                             \
 626         int _ret;                                                       \
 627                                                                         \
 628         do {                                                            \
 629                 _restart_count = bch2_trans_begin(_trans);              \
 630                 _ret = (_do);                                           \
 631         } while (bch2_err_matches(_ret, BCH_ERR_transaction_restart));  \
 632                                                                         \
 633         if (!_ret)                                                      \
 634                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 635                                                                         \
 636         _ret;                                                           \
 637 })
 638
 639 /*
 640  * nested_lockrestart_do(), nested_commit_do():
 641  *
 642  * These are like lockrestart_do() and commit_do(), with two differences:
 643  *
 644  *  - We don't call bch2_trans_begin() unless we had a transaction restart
 645  *  - We return -BCH_ERR_transaction_restart_nested if we succeeded after a
 646  *  transaction restart
 647  */
 648 #define nested_lockrestart_do(_trans, _do)                              \
 649 ({                                                                      \
 650         u32 _restart_count, _orig_restart_count;                        \
 651         int _ret;                                                       \
 652                                                                         \
 653         _restart_count = _orig_restart_count = (_trans)->restart_count; \
 654                                                                         \
 655         while (bch2_err_matches(_ret = (_do), BCH_ERR_transaction_restart))\
 656                 _restart_count = bch2_trans_begin(_trans);              \
 657                                                                         \
 658         if (!_ret)                                                      \
 659                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 660                                                                         \
 661         if (!_ret && trans_was_restarted(_trans, _orig_restart_count))  \
 662                 _ret = -BCH_ERR_transaction_restart_nested;             \
 663                                                                         \
 664         _ret;                                                           \
 665 })
 666
 667 #define for_each_btree_key2(_trans, _iter, _btree_id,                   \
 668                             _start, _flags, _k, _do)                    \
 669 ({                                                                      \
 670         int _ret = 0;                                                   \
 671                                                                         \
 672         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 673                              (_start), (_flags));                       \
 674                                                                         \
 675         while (1) {                                                     \
 676                 u32 _restart_count = bch2_trans_begin(_trans);          \
 677                                                                         \
 678                 _ret = 0;                                               \
 679                 (_k) = bch2_btree_iter_peek_type(&(_iter), (_flags));   \
 680                 if (!(_k).k)                                            \
 681                         break;                                          \
 682                                                                         \
 683                 _ret = bkey_err(_k) ?: (_do);                           \
 684                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 685                         continue;                                       \
 686                 if (_ret)                                               \
 687                         break;                                          \
 688                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 689                 if (!bch2_btree_iter_advance(&(_iter)))                 \
 690                         break;                                          \
 691         }                                                               \
 692                                                                         \
 693         bch2_trans_iter_exit((_trans), &(_iter));                       \
 694         _ret;                                                           \
 695 })
 696
 697 #define for_each_btree_key2_upto(_trans, _iter, _btree_id,              \
 698                             _start, _end, _flags, _k, _do)              \
 699 ({                                                                      \
 700         int _ret = 0;                                                   \
 701                                                                         \
 702         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 703                              (_start), (_flags));                       \
 704                                                                         \
 705         while (1) {                                                     \
 706                 u32 _restart_count = bch2_trans_begin(_trans);          \
 707                                                                         \
 708                 _ret = 0;                                               \
 709                 (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, (_flags));\
 710                 if (!(_k).k)                                            \
 711                         break;                                          \
 712                                                                         \
 713                 _ret = bkey_err(_k) ?: (_do);                           \
 714                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 715                         continue;                                       \
 716                 if (_ret)                                               \
 717                         break;                                          \
 718                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 719                 if (!bch2_btree_iter_advance(&(_iter)))                 \
 720                         break;                                          \
 721         }                                                               \
 722                                                                         \
 723         bch2_trans_iter_exit((_trans), &(_iter));                       \
 724         _ret;                                                           \
 725 })
 726
 727 #define for_each_btree_key_reverse(_trans, _iter, _btree_id,            \
 728                                    _start, _flags, _k, _do)             \
 729 ({                                                                      \
 730         int _ret = 0;                                                   \
 731                                                                         \
 732         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 733                              (_start), (_flags));                       \
 734                                                                         \
 735         while (1) {                                                     \
 736                 u32 _restart_count = bch2_trans_begin(_trans);          \
 737                 (_k) = bch2_btree_iter_peek_prev_type(&(_iter), (_flags));\
 738                 if (!(_k).k) {                                          \
 739                         _ret = 0;                                       \
 740                         break;                                          \
 741                 }                                                       \
 742                                                                         \
 743                 _ret = bkey_err(_k) ?: (_do);                           \
 744                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 745                         continue;                                       \
 746                 if (_ret)                                               \
 747                         break;                                          \
 748                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 749                 if (!bch2_btree_iter_rewind(&(_iter)))                  \
 750                         break;                                          \
 751         }                                                               \
 752                                                                         \
 753         bch2_trans_iter_exit((_trans), &(_iter));                       \
 754         _ret;                                                           \
 755 })
 756
 757 #define for_each_btree_key_commit(_trans, _iter, _btree_id,             \
 758                                   _start, _iter_flags, _k,              \
 759                                   _disk_res, _journal_seq, _commit_flags,\
 760                                   _do)                                  \
 761         for_each_btree_key2(_trans, _iter, _btree_id, _start, _iter_flags, _k,\
 762                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 763                                         (_journal_seq), (_commit_flags)))
 764
 765 #define for_each_btree_key_upto_commit(_trans, _iter, _btree_id,        \
 766                                   _start, _end, _iter_flags, _k,        \
 767                                   _disk_res, _journal_seq, _commit_flags,\
 768                                   _do)                                  \
 769         for_each_btree_key2_upto(_trans, _iter, _btree_id, _start, _end, _iter_flags, _k,\
 770                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 771                                         (_journal_seq), (_commit_flags)))
 772
 773 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 774                            _start, _flags, _k, _ret)                    \
 775         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 776                                   (_start), (_flags));                  \
 777              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 778              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 779              bch2_btree_iter_advance(&(_iter)))
 780
 781 #define for_each_btree_key_upto(_trans, _iter, _btree_id,               \
 782                                 _start, _end, _flags, _k, _ret)         \
 783         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 784                                   (_start), (_flags));                  \
 785              (_k) = __bch2_btree_iter_peek_upto_and_restart((_trans),   \
 786                                                 &(_iter), _end, _flags),\
 787              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 788              bch2_btree_iter_advance(&(_iter)))
 789
 790 #define for_each_btree_key_norestart(_trans, _iter, _btree_id,          \
 791                            _start, _flags, _k, _ret)                    \
 792         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 793                                   (_start), (_flags));                  \
 794              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 795              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 796              bch2_btree_iter_advance(&(_iter)))
 797
 798 #define for_each_btree_key_upto_norestart(_trans, _iter, _btree_id,     \
 799                            _start, _end, _flags, _k, _ret)              \
 800         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 801                                   (_start), (_flags));                  \
 802              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),\
 803              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 804              bch2_btree_iter_advance(&(_iter)))
 805
 806 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _ret)    \
 807         for (;                                                          \
 808              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 809              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 810              bch2_btree_iter_advance(&(_iter)))
 811
 812 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
 813         for (;                                                          \
 814              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 815              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 816              bch2_btree_iter_advance(&(_iter)))
 817
 818 #define for_each_btree_key_upto_continue_norestart(_iter, _end, _flags, _k, _ret)\
 819         for (;                                                                  \
 820              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),     \
 821              !((_ret) = bkey_err(_k)) && (_k).k;                                \
 822              bch2_btree_iter_advance(&(_iter)))
 823
 824 /* new multiple iterator interface: */
 825
 826 void bch2_trans_updates_to_text(struct printbuf *, struct btree_trans *);
 827 void bch2_btree_path_to_text(struct printbuf *, struct btree_path *);
 828 void bch2_trans_paths_to_text(struct printbuf *, struct btree_trans *);
 829 void bch2_dump_trans_updates(struct btree_trans *);
 830 void bch2_dump_trans_paths_updates(struct btree_trans *);
 831 void __bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned);
 832 void bch2_trans_exit(struct btree_trans *);
 833
 834 extern const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR];
 835 unsigned bch2_trans_get_fn_idx(const char *);
 836
 837 #define bch2_trans_init(_trans, _c, _nr_iters, _mem)                    \
 838 do {                                                                    \
 839         static unsigned trans_fn_idx;                                   \
 840                                                                         \
 841         if (unlikely(!trans_fn_idx))                                    \
 842                 trans_fn_idx = bch2_trans_get_fn_idx(__func__);         \
 843                                                                         \
 844         __bch2_trans_init(_trans, _c, trans_fn_idx);                    \
 845 } while (0)
 846
 847 void bch2_btree_trans_to_text(struct printbuf *, struct btree_trans *);
 848
 849 void bch2_fs_btree_iter_exit(struct bch_fs *);
 850 int bch2_fs_btree_iter_init(struct bch_fs *);
 851
 852 #endif /* _BCACHEFS_BTREE_ITER_H */