fs/bcachefs/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 #include "trace.h"
   8
   9 static inline int __bkey_err(const struct bkey *k)
  10 {
  11         return PTR_ERR_OR_ZERO(k);
  12 }
  13
  14 #define bkey_err(_k)    __bkey_err((_k).k)
  15
  16 static inline void __btree_path_get(struct btree_path *path, bool intent)
  17 {
  18         path->ref++;
  19         path->intent_ref += intent;
  20 }
  21
  22 static inline bool __btree_path_put(struct btree_path *path, bool intent)
  23 {
  24         EBUG_ON(!path->ref);
  25         EBUG_ON(!path->intent_ref && intent);
  26         path->intent_ref -= intent;
  27         return --path->ref == 0;
  28 }
  29
  30 static inline void btree_path_set_dirty(struct btree_path *path,
  31                                         enum btree_path_uptodate u)
  32 {
  33         path->uptodate = max_t(unsigned, path->uptodate, u);
  34 }
  35
  36 static inline struct btree *btree_path_node(struct btree_path *path,
  37                                             unsigned level)
  38 {
  39         return level < BTREE_MAX_DEPTH ? path->l[level].b : NULL;
  40 }
  41
  42 static inline bool btree_node_lock_seq_matches(const struct btree_path *path,
  43                                         const struct btree *b, unsigned level)
  44 {
  45         return path->l[level].lock_seq == six_lock_seq(&b->c.lock);
  46 }
  47
  48 static inline struct btree *btree_node_parent(struct btree_path *path,
  49                                               struct btree *b)
  50 {
  51         return btree_path_node(path, b->c.level + 1);
  52 }
  53
  54 /* Iterate over paths within a transaction: */
  55
  56 void __bch2_btree_trans_sort_paths(struct btree_trans *);
  57
  58 static inline void btree_trans_sort_paths(struct btree_trans *trans)
  59 {
  60         if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
  61             trans->paths_sorted)
  62                 return;
  63         __bch2_btree_trans_sort_paths(trans);
  64 }
  65
  66 static inline unsigned long *trans_paths_nr(struct btree_path *paths)
  67 {
  68         return &container_of(paths, struct btree_trans_paths, paths[0])->nr_paths;
  69 }
  70
  71 static inline unsigned long *trans_paths_allocated(struct btree_path *paths)
  72 {
  73         unsigned long *v = trans_paths_nr(paths);
  74         return v - BITS_TO_LONGS(*v);
  75 }
  76
  77 #define trans_for_each_path_idx_from(_paths_allocated, _nr, _idx, _start)\
  78         for (_idx = _start;                                             \
  79              (_idx = find_next_bit(_paths_allocated, _nr, _idx)) < _nr; \
  80              _idx++)
  81
  82 static inline struct btree_path *
  83 __trans_next_path(struct btree_trans *trans, unsigned *idx)
  84 {
  85         unsigned long *w = trans->paths_allocated + *idx / BITS_PER_LONG;
  86         /*
  87          * Open coded find_next_bit(), because
  88          *  - this is fast path, we can't afford the function call
  89          *  - and we know that nr_paths is a multiple of BITS_PER_LONG,
  90          */
  91         while (*idx < trans->nr_paths) {
  92                 unsigned long v = *w >> (*idx & (BITS_PER_LONG - 1));
  93                 if (v) {
  94                         *idx += __ffs(v);
  95                         return trans->paths + *idx;
  96                 }
  97
  98                 *idx += BITS_PER_LONG;
  99                 *idx &= ~(BITS_PER_LONG - 1);
 100                 w++;
 101         }
 102
 103         return NULL;
 104 }
 105
 106 /*
 107  * This version is intended to be safe for use on a btree_trans that is owned by
 108  * another thread, for bch2_btree_trans_to_text();
 109  */
 110 #define trans_for_each_path_from(_trans, _path, _idx, _start)           \
 111         for (_idx = _start;                                             \
 112              (_path = __trans_next_path((_trans), &_idx));              \
 113              _idx++)
 114
 115 #define trans_for_each_path(_trans, _path, _idx)                        \
 116         trans_for_each_path_from(_trans, _path, _idx, 1)
 117
 118 static inline struct btree_path *next_btree_path(struct btree_trans *trans, struct btree_path *path)
 119 {
 120         unsigned idx = path ? path->sorted_idx + 1 : 0;
 121
 122         EBUG_ON(idx > trans->nr_sorted);
 123
 124         return idx < trans->nr_sorted
 125                 ? trans->paths + trans->sorted[idx]
 126                 : NULL;
 127 }
 128
 129 static inline struct btree_path *prev_btree_path(struct btree_trans *trans, struct btree_path *path)
 130 {
 131         unsigned idx = path ? path->sorted_idx : trans->nr_sorted;
 132
 133         return idx
 134                 ? trans->paths + trans->sorted[idx - 1]
 135                 : NULL;
 136 }
 137
 138 #define trans_for_each_path_idx_inorder(_trans, _iter)                  \
 139         for (_iter = (struct trans_for_each_path_inorder_iter) { 0 };   \
 140              (_iter.path_idx = trans->sorted[_iter.sorted_idx],         \
 141               _iter.sorted_idx < (_trans)->nr_sorted);                  \
 142              _iter.sorted_idx++)
 143
 144 struct trans_for_each_path_inorder_iter {
 145         btree_path_idx_t        sorted_idx;
 146         btree_path_idx_t        path_idx;
 147 };
 148
 149 #define trans_for_each_path_inorder(_trans, _path, _iter)               \
 150         for (_iter = (struct trans_for_each_path_inorder_iter) { 0 };   \
 151              (_iter.path_idx = trans->sorted[_iter.sorted_idx],         \
 152               _path = (_trans)->paths + _iter.path_idx,                 \
 153               _iter.sorted_idx < (_trans)->nr_sorted);                  \
 154              _iter.sorted_idx++)
 155
 156 #define trans_for_each_path_inorder_reverse(_trans, _path, _i)          \
 157         for (_i = trans->nr_sorted - 1;                                 \
 158              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) >= 0;\
 159              --_i)
 160
 161 static inline bool __path_has_node(const struct btree_path *path,
 162                                    const struct btree *b)
 163 {
 164         return path->l[b->c.level].b == b &&
 165                 btree_node_lock_seq_matches(path, b, b->c.level);
 166 }
 167
 168 static inline struct btree_path *
 169 __trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
 170                             unsigned *idx)
 171 {
 172         struct btree_path *path;
 173
 174         while ((path = __trans_next_path(trans, idx)) &&
 175                 !__path_has_node(path, b))
 176                (*idx)++;
 177
 178         return path;
 179 }
 180
 181 #define trans_for_each_path_with_node(_trans, _b, _path, _iter)         \
 182         for (_iter = 1;                                                 \
 183              (_path = __trans_next_path_with_node((_trans), (_b), &_iter));\
 184              _iter++)
 185
 186 btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *, btree_path_idx_t,
 187                                             bool, unsigned long);
 188
 189 static inline btree_path_idx_t __must_check
 190 bch2_btree_path_make_mut(struct btree_trans *trans,
 191                          btree_path_idx_t path, bool intent,
 192                          unsigned long ip)
 193 {
 194         if (trans->paths[path].ref > 1 ||
 195             trans->paths[path].preserve)
 196                 path = __bch2_btree_path_make_mut(trans, path, intent, ip);
 197         trans->paths[path].should_be_locked = false;
 198         return path;
 199 }
 200
 201 btree_path_idx_t __must_check
 202 __bch2_btree_path_set_pos(struct btree_trans *, btree_path_idx_t,
 203                           struct bpos, bool, unsigned long);
 204
 205 static inline btree_path_idx_t __must_check
 206 bch2_btree_path_set_pos(struct btree_trans *trans,
 207                         btree_path_idx_t path, struct bpos new_pos,
 208                         bool intent, unsigned long ip)
 209 {
 210         return !bpos_eq(new_pos, trans->paths[path].pos)
 211                 ? __bch2_btree_path_set_pos(trans, path, new_pos, intent, ip)
 212                 : path;
 213 }
 214
 215 int __must_check bch2_btree_path_traverse_one(struct btree_trans *,
 216                                               btree_path_idx_t,
 217                                               unsigned, unsigned long);
 218
 219 static inline void bch2_trans_verify_not_unlocked(struct btree_trans *);
 220
 221 static inline int __must_check bch2_btree_path_traverse(struct btree_trans *trans,
 222                                           btree_path_idx_t path, unsigned flags)
 223 {
 224         bch2_trans_verify_not_unlocked(trans);
 225
 226         if (trans->paths[path].uptodate < BTREE_ITER_NEED_RELOCK)
 227                 return 0;
 228
 229         return bch2_btree_path_traverse_one(trans, path, flags, _RET_IP_);
 230 }
 231
 232 btree_path_idx_t bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
 233                                  unsigned, unsigned, unsigned, unsigned long);
 234 btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *, enum btree_id,
 235                                             unsigned, struct bpos);
 236
 237 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 238
 239 /*
 240  * bch2_btree_path_peek_slot() for a cached iterator might return a key in a
 241  * different snapshot:
 242  */
 243 static inline struct bkey_s_c bch2_btree_path_peek_slot_exact(struct btree_path *path, struct bkey *u)
 244 {
 245         struct bkey_s_c k = bch2_btree_path_peek_slot(path, u);
 246
 247         if (k.k && bpos_eq(path->pos, k.k->p))
 248                 return k;
 249
 250         bkey_init(u);
 251         u->p = path->pos;
 252         return (struct bkey_s_c) { u, NULL };
 253 }
 254
 255 struct bkey_i *bch2_btree_journal_peek_slot(struct btree_trans *,
 256                                         struct btree_iter *, struct bpos);
 257
 258 void bch2_btree_path_level_init(struct btree_trans *, struct btree_path *, struct btree *);
 259
 260 int __bch2_trans_mutex_lock(struct btree_trans *, struct mutex *);
 261
 262 static inline int bch2_trans_mutex_lock(struct btree_trans *trans, struct mutex *lock)
 263 {
 264         return mutex_trylock(lock)
 265                 ? 0
 266                 : __bch2_trans_mutex_lock(trans, lock);
 267 }
 268
 269 #ifdef CONFIG_BCACHEFS_DEBUG
 270 void bch2_trans_verify_paths(struct btree_trans *);
 271 void bch2_assert_pos_locked(struct btree_trans *, enum btree_id,
 272                             struct bpos, bool);
 273 #else
 274 static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
 275 static inline void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
 276                                           struct bpos pos, bool key_cache) {}
 277 #endif
 278
 279 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
 280                                       struct btree *, struct bkey_packed *);
 281 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
 282                               struct btree *, struct btree_node_iter *,
 283                               struct bkey_packed *, unsigned, unsigned);
 284
 285 int bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);
 286
 287 void bch2_path_put(struct btree_trans *, btree_path_idx_t, bool);
 288
 289 int bch2_trans_relock(struct btree_trans *);
 290 int bch2_trans_relock_notrace(struct btree_trans *);
 291 void bch2_trans_unlock(struct btree_trans *);
 292 void bch2_trans_unlock_long(struct btree_trans *);
 293
 294 static inline int trans_was_restarted(struct btree_trans *trans, u32 restart_count)
 295 {
 296         return restart_count != trans->restart_count
 297                 ? -BCH_ERR_transaction_restart_nested
 298                 : 0;
 299 }
 300
 301 void __noreturn bch2_trans_restart_error(struct btree_trans *, u32);
 302
 303 static inline void bch2_trans_verify_not_restarted(struct btree_trans *trans,
 304                                                    u32 restart_count)
 305 {
 306         if (trans_was_restarted(trans, restart_count))
 307                 bch2_trans_restart_error(trans, restart_count);
 308 }
 309
 310 void __noreturn bch2_trans_in_restart_error(struct btree_trans *);
 311
 312 static inline void bch2_trans_verify_not_in_restart(struct btree_trans *trans)
 313 {
 314         if (trans->restarted)
 315                 bch2_trans_in_restart_error(trans);
 316 }
 317
 318 void __noreturn bch2_trans_unlocked_error(struct btree_trans *);
 319
 320 static inline void bch2_trans_verify_not_unlocked(struct btree_trans *trans)
 321 {
 322         if (!trans->locked)
 323                 bch2_trans_unlocked_error(trans);
 324 }
 325
 326 __always_inline
 327 static int btree_trans_restart_nounlock(struct btree_trans *trans, int err)
 328 {
 329         BUG_ON(err <= 0);
 330         BUG_ON(!bch2_err_matches(-err, BCH_ERR_transaction_restart));
 331
 332         trans->restarted = err;
 333         trans->last_restarted_ip = _THIS_IP_;
 334         return -err;
 335 }
 336
 337 __always_inline
 338 static int btree_trans_restart(struct btree_trans *trans, int err)
 339 {
 340         btree_trans_restart_nounlock(trans, err);
 341         return -err;
 342 }
 343
 344 bool bch2_btree_node_upgrade(struct btree_trans *,
 345                              struct btree_path *, unsigned);
 346
 347 void __bch2_btree_path_downgrade(struct btree_trans *, struct btree_path *, unsigned);
 348
 349 static inline void bch2_btree_path_downgrade(struct btree_trans *trans,
 350                                              struct btree_path *path)
 351 {
 352         unsigned new_locks_want = path->level + !!path->intent_ref;
 353
 354         if (path->locks_want > new_locks_want)
 355                 __bch2_btree_path_downgrade(trans, path, new_locks_want);
 356 }
 357
 358 void bch2_trans_downgrade(struct btree_trans *);
 359
 360 void bch2_trans_node_add(struct btree_trans *trans, struct btree_path *, struct btree *);
 361 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 362
 363 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
 364 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 365
 366 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 367 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *);
 368 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 369
 370 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *, struct bpos);
 371 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 372
 373 static inline struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
 374 {
 375         return bch2_btree_iter_peek_upto(iter, SPOS_MAX);
 376 }
 377
 378 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 379 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 380
 381 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 382 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 383 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 384
 385 bool bch2_btree_iter_advance(struct btree_iter *);
 386 bool bch2_btree_iter_rewind(struct btree_iter *);
 387
 388 static inline void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 389 {
 390         iter->k.type = KEY_TYPE_deleted;
 391         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 392         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 393         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 394         iter->k.size = 0;
 395 }
 396
 397 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 398 {
 399         struct btree_trans *trans = iter->trans;
 400
 401         if (unlikely(iter->update_path))
 402                 bch2_path_put(trans, iter->update_path,
 403                               iter->flags & BTREE_ITER_intent);
 404         iter->update_path = 0;
 405
 406         if (!(iter->flags & BTREE_ITER_all_snapshots))
 407                 new_pos.snapshot = iter->snapshot;
 408
 409         __bch2_btree_iter_set_pos(iter, new_pos);
 410 }
 411
 412 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 413 {
 414         BUG_ON(!(iter->flags & BTREE_ITER_is_extents));
 415         iter->pos = bkey_start_pos(&iter->k);
 416 }
 417
 418 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 419 {
 420         struct bpos pos = iter->pos;
 421
 422         iter->snapshot = snapshot;
 423         pos.snapshot = snapshot;
 424         bch2_btree_iter_set_pos(iter, pos);
 425 }
 426
 427 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 428
 429 static inline unsigned __bch2_btree_iter_flags(struct btree_trans *trans,
 430                                                unsigned btree_id,
 431                                                unsigned flags)
 432 {
 433         if (!(flags & (BTREE_ITER_all_snapshots|BTREE_ITER_not_extents)) &&
 434             btree_id_is_extents(btree_id))
 435                 flags |= BTREE_ITER_is_extents;
 436
 437         if (!(flags & BTREE_ITER_snapshot_field) &&
 438             !btree_type_has_snapshot_field(btree_id))
 439                 flags &= ~BTREE_ITER_all_snapshots;
 440
 441         if (!(flags & BTREE_ITER_all_snapshots) &&
 442             btree_type_has_snapshots(btree_id))
 443                 flags |= BTREE_ITER_filter_snapshots;
 444
 445         if (trans->journal_replay_not_finished)
 446                 flags |= BTREE_ITER_with_journal;
 447
 448         return flags;
 449 }
 450
 451 static inline unsigned bch2_btree_iter_flags(struct btree_trans *trans,
 452                                              unsigned btree_id,
 453                                              unsigned flags)
 454 {
 455         if (!btree_id_cached(trans->c, btree_id)) {
 456                 flags &= ~BTREE_ITER_cached;
 457                 flags &= ~BTREE_ITER_with_key_cache;
 458         } else if (!(flags & BTREE_ITER_cached))
 459                 flags |= BTREE_ITER_with_key_cache;
 460
 461         return __bch2_btree_iter_flags(trans, btree_id, flags);
 462 }
 463
 464 static inline void bch2_trans_iter_init_common(struct btree_trans *trans,
 465                                           struct btree_iter *iter,
 466                                           unsigned btree_id, struct bpos pos,
 467                                           unsigned locks_want,
 468                                           unsigned depth,
 469                                           unsigned flags,
 470                                           unsigned long ip)
 471 {
 472         iter->trans             = trans;
 473         iter->update_path       = 0;
 474         iter->key_cache_path    = 0;
 475         iter->btree_id          = btree_id;
 476         iter->min_depth         = 0;
 477         iter->flags             = flags;
 478         iter->snapshot          = pos.snapshot;
 479         iter->pos               = pos;
 480         iter->k                 = POS_KEY(pos);
 481         iter->journal_idx       = 0;
 482 #ifdef CONFIG_BCACHEFS_DEBUG
 483         iter->ip_allocated = ip;
 484 #endif
 485         iter->path = bch2_path_get(trans, btree_id, iter->pos,
 486                                    locks_want, depth, flags, ip);
 487 }
 488
 489 void bch2_trans_iter_init_outlined(struct btree_trans *, struct btree_iter *,
 490                           enum btree_id, struct bpos, unsigned);
 491
 492 static inline void bch2_trans_iter_init(struct btree_trans *trans,
 493                           struct btree_iter *iter,
 494                           unsigned btree_id, struct bpos pos,
 495                           unsigned flags)
 496 {
 497         if (__builtin_constant_p(btree_id) &&
 498             __builtin_constant_p(flags))
 499                 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
 500                                 bch2_btree_iter_flags(trans, btree_id, flags),
 501                                 _THIS_IP_);
 502         else
 503                 bch2_trans_iter_init_outlined(trans, iter, btree_id, pos, flags);
 504 }
 505
 506 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 507                                enum btree_id, struct bpos,
 508                                unsigned, unsigned, unsigned);
 509 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 510
 511 void bch2_set_btree_iter_dontneed(struct btree_iter *);
 512
 513 void *__bch2_trans_kmalloc(struct btree_trans *, size_t);
 514
 515 static inline void *bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
 516 {
 517         size = roundup(size, 8);
 518
 519         if (likely(trans->mem_top + size <= trans->mem_bytes)) {
 520                 void *p = trans->mem + trans->mem_top;
 521
 522                 trans->mem_top += size;
 523                 memset(p, 0, size);
 524                 return p;
 525         } else {
 526                 return __bch2_trans_kmalloc(trans, size);
 527         }
 528 }
 529
 530 static inline void *bch2_trans_kmalloc_nomemzero(struct btree_trans *trans, size_t size)
 531 {
 532         size = round_up(size, 8);
 533
 534         if (likely(trans->mem_top + size <= trans->mem_bytes)) {
 535                 void *p = trans->mem + trans->mem_top;
 536
 537                 trans->mem_top += size;
 538                 return p;
 539         } else {
 540                 return __bch2_trans_kmalloc(trans, size);
 541         }
 542 }
 543
 544 static inline struct bkey_s_c __bch2_bkey_get_iter(struct btree_trans *trans,
 545                                 struct btree_iter *iter,
 546                                 unsigned btree_id, struct bpos pos,
 547                                 unsigned flags, unsigned type)
 548 {
 549         struct bkey_s_c k;
 550
 551         bch2_trans_iter_init(trans, iter, btree_id, pos, flags);
 552         k = bch2_btree_iter_peek_slot(iter);
 553
 554         if (!bkey_err(k) && type && k.k->type != type)
 555                 k = bkey_s_c_err(-BCH_ERR_ENOENT_bkey_type_mismatch);
 556         if (unlikely(bkey_err(k)))
 557                 bch2_trans_iter_exit(trans, iter);
 558         return k;
 559 }
 560
 561 static inline struct bkey_s_c bch2_bkey_get_iter(struct btree_trans *trans,
 562                                 struct btree_iter *iter,
 563                                 unsigned btree_id, struct bpos pos,
 564                                 unsigned flags)
 565 {
 566         return __bch2_bkey_get_iter(trans, iter, btree_id, pos, flags, 0);
 567 }
 568
 569 #define bch2_bkey_get_iter_typed(_trans, _iter, _btree_id, _pos, _flags, _type)\
 570         bkey_s_c_to_##_type(__bch2_bkey_get_iter(_trans, _iter,                 \
 571                                        _btree_id, _pos, _flags, KEY_TYPE_##_type))
 572
 573 static inline int __bch2_bkey_get_val_typed(struct btree_trans *trans,
 574                                 unsigned btree_id, struct bpos pos,
 575                                 unsigned flags, unsigned type,
 576                                 unsigned val_size, void *val)
 577 {
 578         struct btree_iter iter;
 579         struct bkey_s_c k;
 580         int ret;
 581
 582         k = __bch2_bkey_get_iter(trans, &iter, btree_id, pos, flags, type);
 583         ret = bkey_err(k);
 584         if (!ret) {
 585                 unsigned b = min_t(unsigned, bkey_val_bytes(k.k), val_size);
 586
 587                 memcpy(val, k.v, b);
 588                 if (unlikely(b < sizeof(*val)))
 589                         memset((void *) val + b, 0, sizeof(*val) - b);
 590                 bch2_trans_iter_exit(trans, &iter);
 591         }
 592
 593         return ret;
 594 }
 595
 596 #define bch2_bkey_get_val_typed(_trans, _btree_id, _pos, _flags, _type, _val)\
 597         __bch2_bkey_get_val_typed(_trans, _btree_id, _pos, _flags,      \
 598                                   KEY_TYPE_##_type, sizeof(*_val), _val)
 599
 600 void bch2_trans_srcu_unlock(struct btree_trans *);
 601
 602 u32 bch2_trans_begin(struct btree_trans *);
 603
 604 /*
 605  * XXX
 606  * this does not handle transaction restarts from bch2_btree_iter_next_node()
 607  * correctly
 608  */
 609 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 610                               _locks_want, _depth, _flags, _b, _ret)    \
 611         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 612                                 _start, _locks_want, _depth, _flags);   \
 613              (_b) = bch2_btree_iter_peek_node_and_restart(&(_iter)),    \
 614              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
 615              (_b) = bch2_btree_iter_next_node(&(_iter)))
 616
 617 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 618                             _flags, _b, _ret)                           \
 619         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 620                               0, 0, _flags, _b, _ret)
 621
 622 static inline struct bkey_s_c bch2_btree_iter_peek_prev_type(struct btree_iter *iter,
 623                                                              unsigned flags)
 624 {
 625         return  flags & BTREE_ITER_slots      ? bch2_btree_iter_peek_slot(iter) :
 626                                                 bch2_btree_iter_peek_prev(iter);
 627 }
 628
 629 static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
 630                                                         unsigned flags)
 631 {
 632         return  flags & BTREE_ITER_slots      ? bch2_btree_iter_peek_slot(iter) :
 633                                                 bch2_btree_iter_peek(iter);
 634 }
 635
 636 static inline struct bkey_s_c bch2_btree_iter_peek_upto_type(struct btree_iter *iter,
 637                                                              struct bpos end,
 638                                                              unsigned flags)
 639 {
 640         if (!(flags & BTREE_ITER_slots))
 641                 return bch2_btree_iter_peek_upto(iter, end);
 642
 643         if (bkey_gt(iter->pos, end))
 644                 return bkey_s_c_null;
 645
 646         return bch2_btree_iter_peek_slot(iter);
 647 }
 648
 649 int __bch2_btree_trans_too_many_iters(struct btree_trans *);
 650
 651 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
 652 {
 653         if (bitmap_weight(trans->paths_allocated, trans->nr_paths) > BTREE_ITER_NORMAL_LIMIT - 8)
 654                 return __bch2_btree_trans_too_many_iters(trans);
 655
 656         return 0;
 657 }
 658
 659 /*
 660  * goto instead of loop, so that when used inside for_each_btree_key2()
 661  * break/continue work correctly
 662  */
 663 #define lockrestart_do(_trans, _do)                                     \
 664 ({                                                                      \
 665         __label__ transaction_restart;                                  \
 666         u32 _restart_count;                                             \
 667         int _ret2;                                                      \
 668 transaction_restart:                                                    \
 669         _restart_count = bch2_trans_begin(_trans);                      \
 670         _ret2 = (_do);                                                  \
 671                                                                         \
 672         if (bch2_err_matches(_ret2, BCH_ERR_transaction_restart))       \
 673                 goto transaction_restart;                               \
 674                                                                         \
 675         if (!_ret2)                                                     \
 676                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 677         _ret2;                                                          \
 678 })
 679
 680 /*
 681  * nested_lockrestart_do(), nested_commit_do():
 682  *
 683  * These are like lockrestart_do() and commit_do(), with two differences:
 684  *
 685  *  - We don't call bch2_trans_begin() unless we had a transaction restart
 686  *  - We return -BCH_ERR_transaction_restart_nested if we succeeded after a
 687  *  transaction restart
 688  */
 689 #define nested_lockrestart_do(_trans, _do)                              \
 690 ({                                                                      \
 691         u32 _restart_count, _orig_restart_count;                        \
 692         int _ret2;                                                      \
 693                                                                         \
 694         _restart_count = _orig_restart_count = (_trans)->restart_count; \
 695                                                                         \
 696         while (bch2_err_matches(_ret2 = (_do), BCH_ERR_transaction_restart))\
 697                 _restart_count = bch2_trans_begin(_trans);              \
 698                                                                         \
 699         if (!_ret2)                                                     \
 700                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 701                                                                         \
 702         _ret2 ?: trans_was_restarted(_trans, _restart_count);           \
 703 })
 704
 705 #define for_each_btree_key_upto_continue(_trans, _iter,                 \
 706                                          _end, _flags, _k, _do)         \
 707 ({                                                                      \
 708         struct bkey_s_c _k;                                             \
 709         int _ret3 = 0;                                                  \
 710                                                                         \
 711         do {                                                            \
 712                 _ret3 = lockrestart_do(_trans, ({                       \
 713                         (_k) = bch2_btree_iter_peek_upto_type(&(_iter), \
 714                                                 _end, (_flags));        \
 715                         if (!(_k).k)                                    \
 716                                 break;                                  \
 717                                                                         \
 718                         bkey_err(_k) ?: (_do);                          \
 719                 }));                                                    \
 720         } while (!_ret3 && bch2_btree_iter_advance(&(_iter)));          \
 721                                                                         \
 722         bch2_trans_iter_exit((_trans), &(_iter));                       \
 723         _ret3;                                                          \
 724 })
 725
 726 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _do)     \
 727         for_each_btree_key_upto_continue(_trans, _iter, SPOS_MAX, _flags, _k, _do)
 728
 729 #define for_each_btree_key_upto(_trans, _iter, _btree_id,               \
 730                                 _start, _end, _flags, _k, _do)          \
 731 ({                                                                      \
 732         bch2_trans_begin(trans);                                        \
 733                                                                         \
 734         struct btree_iter _iter;                                        \
 735         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 736                              (_start), (_flags));                       \
 737                                                                         \
 738         for_each_btree_key_upto_continue(_trans, _iter, _end, _flags, _k, _do);\
 739 })
 740
 741 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 742                            _start, _flags, _k, _do)                     \
 743         for_each_btree_key_upto(_trans, _iter, _btree_id, _start,       \
 744                                  SPOS_MAX, _flags, _k, _do)
 745
 746 #define for_each_btree_key_reverse(_trans, _iter, _btree_id,            \
 747                                    _start, _flags, _k, _do)             \
 748 ({                                                                      \
 749         struct btree_iter _iter;                                        \
 750         struct bkey_s_c _k;                                             \
 751         int _ret3 = 0;                                                  \
 752                                                                         \
 753         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 754                              (_start), (_flags));                       \
 755                                                                         \
 756         do {                                                            \
 757                 _ret3 = lockrestart_do(_trans, ({                       \
 758                         (_k) = bch2_btree_iter_peek_prev_type(&(_iter), \
 759                                                         (_flags));      \
 760                         if (!(_k).k)                                    \
 761                                 break;                                  \
 762                                                                         \
 763                         bkey_err(_k) ?: (_do);                          \
 764                 }));                                                    \
 765         } while (!_ret3 && bch2_btree_iter_rewind(&(_iter)));           \
 766                                                                         \
 767         bch2_trans_iter_exit((_trans), &(_iter));                       \
 768         _ret3;                                                          \
 769 })
 770
 771 #define for_each_btree_key_commit(_trans, _iter, _btree_id,             \
 772                                   _start, _iter_flags, _k,              \
 773                                   _disk_res, _journal_seq, _commit_flags,\
 774                                   _do)                                  \
 775         for_each_btree_key(_trans, _iter, _btree_id, _start, _iter_flags, _k,\
 776                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 777                                         (_journal_seq), (_commit_flags)))
 778
 779 #define for_each_btree_key_reverse_commit(_trans, _iter, _btree_id,     \
 780                                   _start, _iter_flags, _k,              \
 781                                   _disk_res, _journal_seq, _commit_flags,\
 782                                   _do)                                  \
 783         for_each_btree_key_reverse(_trans, _iter, _btree_id, _start, _iter_flags, _k,\
 784                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 785                                         (_journal_seq), (_commit_flags)))
 786
 787 #define for_each_btree_key_upto_commit(_trans, _iter, _btree_id,        \
 788                                   _start, _end, _iter_flags, _k,        \
 789                                   _disk_res, _journal_seq, _commit_flags,\
 790                                   _do)                                  \
 791         for_each_btree_key_upto(_trans, _iter, _btree_id, _start, _end, _iter_flags, _k,\
 792                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 793                                         (_journal_seq), (_commit_flags)))
 794
 795 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *);
 796
 797 static inline struct bkey_s_c
 798 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 799                                    struct btree_iter *iter, unsigned flags)
 800 {
 801         struct bkey_s_c k;
 802
 803         while (btree_trans_too_many_iters(trans) ||
 804                (k = bch2_btree_iter_peek_type(iter, flags),
 805                 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
 806                 bch2_trans_begin(trans);
 807
 808         return k;
 809 }
 810
 811 #define for_each_btree_key_upto_norestart(_trans, _iter, _btree_id,     \
 812                            _start, _end, _flags, _k, _ret)              \
 813         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 814                                   (_start), (_flags));                  \
 815              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),\
 816              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 817              bch2_btree_iter_advance(&(_iter)))
 818
 819 #define for_each_btree_key_upto_continue_norestart(_iter, _end, _flags, _k, _ret)\
 820         for (;                                                                  \
 821              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),     \
 822              !((_ret) = bkey_err(_k)) && (_k).k;                                \
 823              bch2_btree_iter_advance(&(_iter)))
 824
 825 #define for_each_btree_key_norestart(_trans, _iter, _btree_id,          \
 826                            _start, _flags, _k, _ret)                    \
 827         for_each_btree_key_upto_norestart(_trans, _iter, _btree_id, _start,\
 828                                           SPOS_MAX, _flags, _k, _ret)
 829
 830 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
 831         for_each_btree_key_upto_continue_norestart(_iter, SPOS_MAX, _flags, _k, _ret)
 832
 833 /*
 834  * This should not be used in a fastpath, without first trying _do in
 835  * nonblocking mode - it will cause excessive transaction restarts and
 836  * potentially livelocking:
 837  */
 838 #define drop_locks_do(_trans, _do)                                      \
 839 ({                                                                      \
 840         bch2_trans_unlock(_trans);                                      \
 841         _do ?: bch2_trans_relock(_trans);                               \
 842 })
 843
 844 #define allocate_dropping_locks_errcode(_trans, _do)                    \
 845 ({                                                                      \
 846         gfp_t _gfp = GFP_NOWAIT|__GFP_NOWARN;                           \
 847         int _ret = _do;                                                 \
 848                                                                         \
 849         if (bch2_err_matches(_ret, ENOMEM)) {                           \
 850                 _gfp = GFP_KERNEL;                                      \
 851                 _ret = drop_locks_do(trans, _do);                       \
 852         }                                                               \
 853         _ret;                                                           \
 854 })
 855
 856 #define allocate_dropping_locks(_trans, _ret, _do)                      \
 857 ({                                                                      \
 858         gfp_t _gfp = GFP_NOWAIT|__GFP_NOWARN;                           \
 859         typeof(_do) _p = _do;                                           \
 860                                                                         \
 861         _ret = 0;                                                       \
 862         if (unlikely(!_p)) {                                            \
 863                 _gfp = GFP_KERNEL;                                      \
 864                 _ret = drop_locks_do(trans, ((_p = _do), 0));           \
 865         }                                                               \
 866         _p;                                                             \
 867 })
 868
 869 void bch2_trans_updates_to_text(struct printbuf *, struct btree_trans *);
 870 void bch2_btree_path_to_text(struct printbuf *, struct btree_trans *, btree_path_idx_t);
 871 void bch2_trans_paths_to_text(struct printbuf *, struct btree_trans *);
 872 void bch2_dump_trans_updates(struct btree_trans *);
 873 void bch2_dump_trans_paths_updates(struct btree_trans *);
 874
 875 struct btree_trans *__bch2_trans_get(struct bch_fs *, unsigned);
 876 void bch2_trans_put(struct btree_trans *);
 877
 878 extern const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR];
 879 unsigned bch2_trans_get_fn_idx(const char *);
 880
 881 #define bch2_trans_get(_c)                                              \
 882 ({                                                                      \
 883         static unsigned trans_fn_idx;                                   \
 884                                                                         \
 885         if (unlikely(!trans_fn_idx))                                    \
 886                 trans_fn_idx = bch2_trans_get_fn_idx(__func__);         \
 887         __bch2_trans_get(_c, trans_fn_idx);                             \
 888 })
 889
 890 void bch2_btree_trans_to_text(struct printbuf *, struct btree_trans *);
 891
 892 void bch2_fs_btree_iter_exit(struct bch_fs *);
 893 void bch2_fs_btree_iter_init_early(struct bch_fs *);
 894 int bch2_fs_btree_iter_init(struct bch_fs *);
 895
 896 #endif /* _BCACHEFS_BTREE_ITER_H */