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 static inline struct btree_path *
  58 __trans_next_path(struct btree_trans *trans, unsigned idx)
  59 {
  60         u64 l;
  61
  62         if (idx == BTREE_ITER_MAX)
  63                 return NULL;
  64
  65         l = trans->paths_allocated >> idx;
  66         if (!l)
  67                 return NULL;
  68
  69         idx += __ffs64(l);
  70         EBUG_ON(idx >= BTREE_ITER_MAX);
  71         EBUG_ON(trans->paths[idx].idx != idx);
  72         return &trans->paths[idx];
  73 }
  74
  75 void bch2_btree_path_check_sort(struct btree_trans *, struct btree_path *, int);
  76
  77 #define trans_for_each_path(_trans, _path)                              \
  78         for (_path = __trans_next_path((_trans), 0);                    \
  79              (_path);                                                   \
  80              _path = __trans_next_path((_trans), (_path)->idx + 1))
  81
  82 static inline struct btree_path *next_btree_path(struct btree_trans *trans, struct btree_path *path)
  83 {
  84         unsigned idx = path ? path->sorted_idx + 1 : 0;
  85
  86         EBUG_ON(idx > trans->nr_sorted);
  87
  88         return idx < trans->nr_sorted
  89                 ? trans->paths + trans->sorted[idx]
  90                 : NULL;
  91 }
  92
  93 static inline struct btree_path *prev_btree_path(struct btree_trans *trans, struct btree_path *path)
  94 {
  95         EBUG_ON(path->sorted_idx >= trans->nr_sorted);
  96         return path->sorted_idx
  97                 ? trans->paths + trans->sorted[path->sorted_idx - 1]
  98                 : NULL;
  99 }
 100
 101 #define trans_for_each_path_inorder(_trans, _path, _i)                  \
 102         for (_i = 0;                                                    \
 103              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) < (_trans)->nr_sorted;\
 104              _i++)
 105
 106 static inline bool __path_has_node(const struct btree_path *path,
 107                                    const struct btree *b)
 108 {
 109         return path->l[b->c.level].b == b &&
 110                 btree_node_lock_seq_matches(path, b, b->c.level);
 111 }
 112
 113 static inline struct btree_path *
 114 __trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
 115                             unsigned idx)
 116 {
 117         struct btree_path *path = __trans_next_path(trans, idx);
 118
 119         while (path && !__path_has_node(path, b))
 120                 path = __trans_next_path(trans, path->idx + 1);
 121
 122         return path;
 123 }
 124
 125 #define trans_for_each_path_with_node(_trans, _b, _path)                \
 126         for (_path = __trans_next_path_with_node((_trans), (_b), 0);    \
 127              (_path);                                                   \
 128              _path = __trans_next_path_with_node((_trans), (_b),        \
 129                                                  (_path)->idx + 1))
 130
 131 struct btree_path * __must_check
 132 bch2_btree_path_make_mut(struct btree_trans *, struct btree_path *,
 133                          bool, unsigned long);
 134 struct btree_path * __must_check
 135 bch2_btree_path_set_pos(struct btree_trans *, struct btree_path *,
 136                         struct bpos, bool, unsigned long);
 137 int __must_check bch2_btree_path_traverse(struct btree_trans *,
 138                                           struct btree_path *, unsigned);
 139 struct btree_path *bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
 140                                  unsigned, unsigned, unsigned, unsigned long);
 141 inline struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 142
 143 struct bkey_i *bch2_btree_journal_peek_slot(struct btree_trans *,
 144                                         struct btree_iter *, struct bpos);
 145
 146 #ifdef CONFIG_BCACHEFS_DEBUG
 147 void bch2_trans_verify_paths(struct btree_trans *);
 148 void bch2_assert_pos_locked(struct btree_trans *, enum btree_id,
 149                             struct bpos, bool);
 150 #else
 151 static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
 152 static inline void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
 153                                           struct bpos pos, bool key_cache) {}
 154 #endif
 155
 156 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
 157                                       struct btree *, struct bkey_packed *);
 158 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
 159                               struct btree *, struct btree_node_iter *,
 160                               struct bkey_packed *, unsigned, unsigned);
 161
 162 int bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);
 163
 164 void bch2_path_put(struct btree_trans *, struct btree_path *, bool);
 165
 166 int bch2_trans_relock(struct btree_trans *);
 167 void bch2_trans_unlock(struct btree_trans *);
 168
 169 static inline bool trans_was_restarted(struct btree_trans *trans, u32 restart_count)
 170 {
 171         return restart_count != trans->restart_count;
 172 }
 173
 174 void bch2_trans_verify_not_restarted(struct btree_trans *, u32);
 175
 176 __always_inline
 177 static inline int btree_trans_restart_nounlock(struct btree_trans *trans, int err)
 178 {
 179         BUG_ON(err <= 0);
 180         BUG_ON(!bch2_err_matches(err, BCH_ERR_transaction_restart));
 181
 182         trans->restarted = err;
 183         return -err;
 184 }
 185
 186 __always_inline
 187 static inline int btree_trans_restart(struct btree_trans *trans, int err)
 188 {
 189         btree_trans_restart_nounlock(trans, err);
 190         return -err;
 191 }
 192
 193 bool bch2_btree_node_upgrade(struct btree_trans *,
 194                              struct btree_path *, unsigned);
 195
 196 void __bch2_btree_path_downgrade(struct btree_trans *, struct btree_path *, unsigned);
 197
 198 static inline void bch2_btree_path_downgrade(struct btree_trans *trans,
 199                                              struct btree_path *path)
 200 {
 201         unsigned new_locks_want = path->level + !!path->intent_ref;
 202
 203         if (path->locks_want > new_locks_want)
 204                 __bch2_btree_path_downgrade(trans, path, new_locks_want);
 205 }
 206
 207 void bch2_trans_downgrade(struct btree_trans *);
 208
 209 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
 210 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 211
 212 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
 213 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 214
 215 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 216 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 217
 218 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *, struct bpos);
 219 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 220
 221 struct bkey_s_c bch2_btree_iter_peek_all_levels(struct btree_iter *);
 222
 223 static inline struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
 224 {
 225         return bch2_btree_iter_peek_upto(iter, SPOS_MAX);
 226 }
 227
 228 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 229 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 230
 231 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 232 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 233 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 234
 235 bool bch2_btree_iter_advance(struct btree_iter *);
 236 bool bch2_btree_iter_rewind(struct btree_iter *);
 237
 238 static inline void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 239 {
 240         iter->k.type = KEY_TYPE_deleted;
 241         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 242         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 243         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 244         iter->k.size = 0;
 245 }
 246
 247 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 248 {
 249         if (unlikely(iter->update_path))
 250                 bch2_path_put(iter->trans, iter->update_path,
 251                               iter->flags & BTREE_ITER_INTENT);
 252         iter->update_path = NULL;
 253
 254         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 255                 new_pos.snapshot = iter->snapshot;
 256
 257         __bch2_btree_iter_set_pos(iter, new_pos);
 258 }
 259
 260 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 261 {
 262         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 263         iter->pos = bkey_start_pos(&iter->k);
 264 }
 265
 266 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 267 {
 268         struct bpos pos = iter->pos;
 269
 270         iter->snapshot = snapshot;
 271         pos.snapshot = snapshot;
 272         bch2_btree_iter_set_pos(iter, pos);
 273 }
 274
 275 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 276 void bch2_trans_iter_init(struct btree_trans *, struct btree_iter *,
 277                           unsigned, struct bpos, unsigned);
 278 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 279                                enum btree_id, struct bpos,
 280                                unsigned, unsigned, unsigned);
 281 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 282
 283 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 284 {
 285         if (!iter->trans->restarted)
 286                 iter->path->preserve = false;
 287 }
 288
 289 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 290 u32 bch2_trans_begin(struct btree_trans *);
 291
 292 static inline struct btree *
 293 __btree_iter_peek_node_and_restart(struct btree_trans *trans, struct btree_iter *iter)
 294 {
 295         struct btree *b;
 296
 297         while (b = bch2_btree_iter_peek_node(iter),
 298                bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart))
 299                 bch2_trans_begin(trans);
 300
 301         return b;
 302 }
 303
 304 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 305                               _locks_want, _depth, _flags, _b, _ret)    \
 306         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 307                                 _start, _locks_want, _depth, _flags);   \
 308              (_b) = __btree_iter_peek_node_and_restart((_trans), &(_iter)),\
 309              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
 310              (_b) = bch2_btree_iter_next_node(&(_iter)))
 311
 312 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 313                             _flags, _b, _ret)                           \
 314         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 315                               0, 0, _flags, _b, _ret)
 316
 317 static inline int bkey_err(struct bkey_s_c k)
 318 {
 319         return PTR_ERR_OR_ZERO(k.k);
 320 }
 321
 322 static inline struct bkey_s_c bch2_btree_iter_peek_prev_type(struct btree_iter *iter,
 323                                                              unsigned flags)
 324 {
 325         BUG_ON(flags & BTREE_ITER_ALL_LEVELS);
 326
 327         return  flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
 328                                                 bch2_btree_iter_peek_prev(iter);
 329 }
 330
 331 static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
 332                                                         unsigned flags)
 333 {
 334         return  flags & BTREE_ITER_ALL_LEVELS ? bch2_btree_iter_peek_all_levels(iter) :
 335                 flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
 336                                                 bch2_btree_iter_peek(iter);
 337 }
 338
 339 static inline struct bkey_s_c bch2_btree_iter_peek_upto_type(struct btree_iter *iter,
 340                                                              struct bpos end,
 341                                                              unsigned flags)
 342 {
 343         if (!(flags & BTREE_ITER_SLOTS))
 344                 return bch2_btree_iter_peek_upto(iter, end);
 345
 346         if (bkey_cmp(iter->pos, end) > 0)
 347                 return bkey_s_c_null;
 348
 349         return bch2_btree_iter_peek_slot(iter);
 350 }
 351
 352 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
 353 {
 354         if (hweight64(trans->paths_allocated) > BTREE_ITER_MAX - 8) {
 355                 trace_and_count(trans->c, trans_restart_too_many_iters, trans, _THIS_IP_);
 356                 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters);
 357         }
 358
 359         return 0;
 360 }
 361
 362 static inline struct bkey_s_c
 363 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 364                                    struct btree_iter *iter, unsigned flags)
 365 {
 366         struct bkey_s_c k;
 367
 368         while (btree_trans_too_many_iters(trans) ||
 369                (k = bch2_btree_iter_peek_type(iter, flags),
 370                 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
 371                 bch2_trans_begin(trans);
 372
 373         return k;
 374 }
 375
 376 #define lockrestart_do(_trans, _do)                                     \
 377 ({                                                                      \
 378         u32 _restart_count;                                             \
 379         int _ret;                                                       \
 380                                                                         \
 381         do {                                                            \
 382                 _restart_count = bch2_trans_begin(_trans);              \
 383                 _ret = (_do);                                           \
 384         } while (bch2_err_matches(_ret, BCH_ERR_transaction_restart));  \
 385                                                                         \
 386         if (!_ret)                                                      \
 387                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 388                                                                         \
 389         _ret;                                                           \
 390 })
 391
 392 /*
 393  * nested_lockrestart_do(), nested_commit_do():
 394  *
 395  * These are like lockrestart_do() and commit_do(), with two differences:
 396  *
 397  *  - We don't call bch2_trans_begin() unless we had a transaction restart
 398  *  - We return -BCH_ERR_transaction_restart_nested if we succeeded after a
 399  *  transaction restart
 400  */
 401 #define nested_lockrestart_do(_trans, _do)                              \
 402 ({                                                                      \
 403         u32 _restart_count, _orig_restart_count;                        \
 404         int _ret;                                                       \
 405                                                                         \
 406         _restart_count = _orig_restart_count = (_trans)->restart_count; \
 407                                                                         \
 408         while (bch2_err_matches(_ret = (_do), BCH_ERR_transaction_restart))\
 409                 _restart_count = bch2_trans_begin(_trans);              \
 410                                                                         \
 411         if (!_ret)                                                      \
 412                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 413                                                                         \
 414         if (!_ret && trans_was_restarted(_trans, _orig_restart_count))  \
 415                 _ret = -BCH_ERR_transaction_restart_nested;             \
 416                                                                         \
 417         _ret;                                                           \
 418 })
 419
 420 #define for_each_btree_key2(_trans, _iter, _btree_id,                   \
 421                             _start, _flags, _k, _do)                    \
 422 ({                                                                      \
 423         int _ret = 0;                                                   \
 424                                                                         \
 425         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 426                              (_start), (_flags));                       \
 427                                                                         \
 428         while (1) {                                                     \
 429                 u32 _restart_count = bch2_trans_begin(_trans);          \
 430                 (_k) = bch2_btree_iter_peek_type(&(_iter), (_flags));   \
 431                 if (!(_k).k) {                                          \
 432                         _ret = 0;                                       \
 433                         break;                                          \
 434                 }                                                       \
 435                                                                         \
 436                 _ret = bkey_err(_k) ?: (_do);                           \
 437                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 438                         continue;                                       \
 439                 if (_ret)                                               \
 440                         break;                                          \
 441                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 442                 if (!bch2_btree_iter_advance(&(_iter)))                 \
 443                         break;                                          \
 444         }                                                               \
 445                                                                         \
 446         bch2_trans_iter_exit((_trans), &(_iter));                       \
 447         _ret;                                                           \
 448 })
 449
 450 #define for_each_btree_key_reverse(_trans, _iter, _btree_id,            \
 451                                    _start, _flags, _k, _do)             \
 452 ({                                                                      \
 453         int _ret = 0;                                                   \
 454                                                                         \
 455         bch2_trans_iter_init((_trans), &(_iter), (_btree_id),           \
 456                              (_start), (_flags));                       \
 457                                                                         \
 458         while (1) {                                                     \
 459                 u32 _restart_count = bch2_trans_begin(_trans);          \
 460                 (_k) = bch2_btree_iter_peek_prev_type(&(_iter), (_flags));\
 461                 if (!(_k).k) {                                          \
 462                         _ret = 0;                                       \
 463                         break;                                          \
 464                 }                                                       \
 465                                                                         \
 466                 _ret = bkey_err(_k) ?: (_do);                           \
 467                 if (bch2_err_matches(_ret, BCH_ERR_transaction_restart))\
 468                         continue;                                       \
 469                 if (_ret)                                               \
 470                         break;                                          \
 471                 bch2_trans_verify_not_restarted(_trans, _restart_count);\
 472                 if (!bch2_btree_iter_rewind(&(_iter)))                  \
 473                         break;                                          \
 474         }                                                               \
 475                                                                         \
 476         bch2_trans_iter_exit((_trans), &(_iter));                       \
 477         _ret;                                                           \
 478 })
 479
 480 #define for_each_btree_key_commit(_trans, _iter, _btree_id,             \
 481                                   _start, _iter_flags, _k,              \
 482                                   _disk_res, _journal_seq, _commit_flags,\
 483                                   _do)                                  \
 484         for_each_btree_key2(_trans, _iter, _btree_id, _start, _iter_flags, _k,\
 485                             (_do) ?: bch2_trans_commit(_trans, (_disk_res),\
 486                                         (_journal_seq), (_commit_flags)))
 487
 488 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 489                            _start, _flags, _k, _ret)                    \
 490         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 491                                   (_start), (_flags));                  \
 492              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 493              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 494              bch2_btree_iter_advance(&(_iter)))
 495
 496 #define for_each_btree_key_norestart(_trans, _iter, _btree_id,          \
 497                            _start, _flags, _k, _ret)                    \
 498         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 499                                   (_start), (_flags));                  \
 500              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 501              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 502              bch2_btree_iter_advance(&(_iter)))
 503
 504 #define for_each_btree_key_upto_norestart(_trans, _iter, _btree_id,     \
 505                            _start, _end, _flags, _k, _ret)              \
 506         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 507                                   (_start), (_flags));                  \
 508              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),\
 509              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 510              bch2_btree_iter_advance(&(_iter)))
 511
 512 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _ret)    \
 513         for (;                                                          \
 514              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 515              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 516              bch2_btree_iter_advance(&(_iter)))
 517
 518 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
 519         for (;                                                          \
 520              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 521              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 522              bch2_btree_iter_advance(&(_iter)))
 523
 524 /* new multiple iterator interface: */
 525
 526 void bch2_trans_updates_to_text(struct printbuf *, struct btree_trans *);
 527 void bch2_btree_path_to_text(struct printbuf *, struct btree_path *);
 528 void bch2_trans_paths_to_text(struct printbuf *, struct btree_trans *);
 529 void bch2_dump_trans_updates(struct btree_trans *);
 530 void bch2_dump_trans_paths_updates(struct btree_trans *);
 531 void __bch2_trans_init(struct btree_trans *, struct bch_fs *, const char *);
 532 void bch2_trans_exit(struct btree_trans *);
 533
 534 #define bch2_trans_init(_trans, _c, _nr_iters, _mem) __bch2_trans_init(_trans, _c, __func__)
 535
 536 void bch2_btree_trans_to_text(struct printbuf *, struct btree_trans *);
 537
 538 void bch2_fs_btree_iter_exit(struct bch_fs *);
 539 int bch2_fs_btree_iter_init(struct bch_fs *);
 540
 541 #endif /* _BCACHEFS_BTREE_ITER_H */