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 static inline void btree_iter_set_dirty(struct btree_iter *iter,
   9                                         enum btree_iter_uptodate u)
  10 {
  11         iter->uptodate = max_t(unsigned, iter->uptodate, u);
  12 }
  13
  14 static inline struct btree *btree_iter_node(struct btree_iter *iter,
  15                                             unsigned level)
  16 {
  17         return level < BTREE_MAX_DEPTH ? iter->l[level].b : NULL;
  18 }
  19
  20 static inline bool btree_node_lock_seq_matches(const struct btree_iter *iter,
  21                                         const struct btree *b, unsigned level)
  22 {
  23         /*
  24          * We don't compare the low bits of the lock sequence numbers because
  25          * @iter might have taken a write lock on @b, and we don't want to skip
  26          * the linked iterator if the sequence numbers were equal before taking
  27          * that write lock. The lock sequence number is incremented by taking
  28          * and releasing write locks and is even when unlocked:
  29          */
  30         return iter->l[level].lock_seq >> 1 == b->c.lock.state.seq >> 1;
  31 }
  32
  33 static inline struct btree *btree_node_parent(struct btree_iter *iter,
  34                                               struct btree *b)
  35 {
  36         return btree_iter_node(iter, b->c.level + 1);
  37 }
  38
  39 static inline bool btree_trans_has_multiple_iters(const struct btree_trans *trans)
  40 {
  41         return hweight64(trans->iters_linked) > 1;
  42 }
  43
  44 static inline int btree_iter_err(const struct btree_iter *iter)
  45 {
  46         return iter->flags & BTREE_ITER_ERROR ? -EIO : 0;
  47 }
  48
  49 /* Iterate over iters within a transaction: */
  50
  51 static inline struct btree_iter *
  52 __trans_next_iter(struct btree_trans *trans, unsigned idx)
  53 {
  54         u64 l;
  55
  56         if (idx == BTREE_ITER_MAX)
  57                 return NULL;
  58
  59         l = trans->iters_linked >> idx;
  60         if (!l)
  61                 return NULL;
  62
  63         idx += __ffs64(l);
  64         EBUG_ON(idx >= BTREE_ITER_MAX);
  65         EBUG_ON(trans->iters[idx].idx != idx);
  66         return &trans->iters[idx];
  67 }
  68
  69 #define trans_for_each_iter(_trans, _iter)                              \
  70         for (_iter = __trans_next_iter((_trans), 0);                    \
  71              (_iter);                                                   \
  72              _iter = __trans_next_iter((_trans), (_iter)->idx + 1))
  73
  74 static inline struct btree_iter *next_btree_iter(struct btree_trans *trans, struct btree_iter *iter)
  75 {
  76         unsigned idx = iter ? iter->sorted_idx + 1 : 0;
  77
  78         EBUG_ON(idx > trans->nr_sorted);
  79
  80         return idx < trans->nr_sorted
  81                 ? trans->iters + trans->sorted[idx]
  82                 : NULL;
  83 }
  84
  85 static inline struct btree_iter *prev_btree_iter(struct btree_trans *trans, struct btree_iter *iter)
  86 {
  87         EBUG_ON(iter->sorted_idx >= trans->nr_sorted);
  88         return iter->sorted_idx
  89                 ? trans->iters + trans->sorted[iter->sorted_idx - 1]
  90                 : NULL;
  91 }
  92
  93 #define trans_for_each_iter_inorder(_trans, _iter)                      \
  94         for (_iter = next_btree_iter(trans, NULL);                      \
  95              (_iter);                                                   \
  96              _iter = next_btree_iter((_trans), (_iter)))
  97
  98 static inline bool __iter_has_node(const struct btree_iter *iter,
  99                                    const struct btree *b)
 100 {
 101         return iter->l[b->c.level].b == b &&
 102                 btree_node_lock_seq_matches(iter, b, b->c.level);
 103 }
 104
 105 static inline struct btree_iter *
 106 __trans_next_iter_with_node(struct btree_trans *trans, struct btree *b,
 107                             unsigned idx)
 108 {
 109         struct btree_iter *iter = __trans_next_iter(trans, idx);
 110
 111         while (iter && !__iter_has_node(iter, b))
 112                 iter = __trans_next_iter(trans, iter->idx + 1);
 113
 114         return iter;
 115 }
 116
 117 #define trans_for_each_iter_with_node(_trans, _b, _iter)                \
 118         for (_iter = __trans_next_iter_with_node((_trans), (_b), 0);    \
 119              (_iter);                                                   \
 120              _iter = __trans_next_iter_with_node((_trans), (_b),        \
 121                                                  (_iter)->idx + 1))
 122
 123 #ifdef CONFIG_BCACHEFS_DEBUG
 124 void bch2_btree_trans_verify_iters(struct btree_trans *, struct btree *);
 125 void bch2_btree_trans_verify_locks(struct btree_trans *);
 126 #else
 127 static inline void bch2_btree_trans_verify_iters(struct btree_trans *trans,
 128                                                  struct btree *b) {}
 129 static inline void bch2_btree_trans_verify_locks(struct btree_trans *iter) {}
 130 #endif
 131
 132 void bch2_btree_iter_fix_key_modified(struct btree_iter *, struct btree *,
 133                                            struct bkey_packed *);
 134 void bch2_btree_node_iter_fix(struct btree_iter *, struct btree *,
 135                               struct btree_node_iter *, struct bkey_packed *,
 136                               unsigned, unsigned);
 137
 138 bool bch2_btree_iter_relock_intent(struct btree_iter *);
 139 bool bch2_btree_iter_relock(struct btree_iter *, unsigned long);
 140
 141 bool bch2_trans_relock(struct btree_trans *);
 142 void bch2_trans_unlock(struct btree_trans *);
 143
 144 __always_inline
 145 static inline int btree_trans_restart(struct btree_trans *trans)
 146 {
 147         trans->restarted = true;
 148         bch2_trans_unlock(trans);
 149         return -EINTR;
 150 }
 151
 152 bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
 153
 154 static inline bool bch2_btree_iter_upgrade(struct btree_iter *iter,
 155                                            unsigned new_locks_want)
 156 {
 157         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 158
 159         return iter->locks_want < new_locks_want
 160                 ? __bch2_btree_iter_upgrade(iter, new_locks_want)
 161                 : iter->uptodate <= BTREE_ITER_NEED_PEEK;
 162 }
 163
 164 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 165
 166 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 167 {
 168         unsigned new_locks_want = iter->level + !!(iter->flags & BTREE_ITER_INTENT);
 169
 170         if (iter->locks_want > new_locks_want)
 171                 __bch2_btree_iter_downgrade(iter, new_locks_want);
 172 }
 173
 174 void bch2_trans_downgrade(struct btree_trans *);
 175
 176 void bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
 177 void bch2_btree_iter_node_drop(struct btree_iter *, struct btree *);
 178
 179 void bch2_btree_iter_reinit_node(struct btree_iter *, struct btree *);
 180
 181 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 182
 183 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 184 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 185
 186 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 187 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 188
 189 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 190 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 191
 192 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 193 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 194 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 195
 196 bool bch2_btree_iter_advance(struct btree_iter *);
 197 bool bch2_btree_iter_rewind(struct btree_iter *);
 198
 199 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 200 {
 201         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 202                 new_pos.snapshot = iter->snapshot;
 203
 204         iter->k.type = KEY_TYPE_deleted;
 205         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 206         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 207         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 208         iter->k.size = 0;
 209         iter->should_be_locked = false;
 210 }
 211
 212 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 213 {
 214         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 215         iter->pos = bkey_start_pos(&iter->k);
 216 }
 217
 218 static inline struct btree_iter *idx_to_btree_iter(struct btree_trans *trans, unsigned idx)
 219 {
 220         return idx != U8_MAX ? trans->iters + idx : NULL;
 221 }
 222
 223 static inline struct btree_iter *btree_iter_child(struct btree_iter *iter)
 224 {
 225         return idx_to_btree_iter(iter->trans, iter->child_idx);
 226 }
 227
 228 /*
 229  * Unlocks before scheduling
 230  * Note: does not revalidate iterator
 231  */
 232 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 233 {
 234         if (need_resched() || race_fault()) {
 235                 bch2_trans_unlock(trans);
 236                 schedule();
 237                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 238         } else {
 239                 return 0;
 240         }
 241 }
 242
 243 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 244                               _locks_want, _depth, _flags, _b)          \
 245         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 246                                 _start, _locks_want, _depth, _flags),   \
 247              _b = bch2_btree_iter_peek_node(_iter);                     \
 248              (_b);                                                      \
 249              (_b) = bch2_btree_iter_next_node(_iter))
 250
 251 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 252                             _flags, _b)                                 \
 253         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 254                               0, 0, _flags, _b)
 255
 256 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 257                                                      unsigned flags)
 258 {
 259         return flags & BTREE_ITER_SLOTS
 260                 ? bch2_btree_iter_peek_slot(iter)
 261                 : bch2_btree_iter_peek(iter);
 262 }
 263
 264 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 265                                                      unsigned flags)
 266 {
 267         return flags & BTREE_ITER_SLOTS
 268                 ? bch2_btree_iter_next_slot(iter)
 269                 : bch2_btree_iter_next(iter);
 270 }
 271
 272 static inline int bkey_err(struct bkey_s_c k)
 273 {
 274         return PTR_ERR_OR_ZERO(k.k);
 275 }
 276
 277 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 278                            _start, _flags, _k, _ret)                    \
 279         for ((_iter) = bch2_trans_get_iter((_trans), (_btree_id),       \
 280                                            (_start), (_flags)),         \
 281              (_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 282              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 283              (_k) = __bch2_btree_iter_next(_iter, _flags))
 284
 285 #define for_each_btree_key_continue(_iter, _flags, _k, _ret)            \
 286         for ((_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 287              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 288              (_k) = __bch2_btree_iter_next(_iter, _flags))
 289
 290 /* new multiple iterator interface: */
 291
 292 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
 293 int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
 294
 295 void bch2_trans_unlink_iters(struct btree_trans *);
 296
 297 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
 298                                          struct bpos, unsigned,
 299                                          unsigned, unsigned);
 300
 301 static inline struct btree_iter *
 302 bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
 303                     struct bpos pos, unsigned flags)
 304 {
 305         struct btree_iter *iter =
 306                 __bch2_trans_get_iter(trans, btree_id, pos,
 307                                       (flags & BTREE_ITER_INTENT) != 0, 0,
 308                                       flags);
 309         iter->ip_allocated = _THIS_IP_;
 310         return iter;
 311 }
 312
 313 struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *,
 314                                         struct btree_iter *);
 315 static inline struct btree_iter *
 316 bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src)
 317 {
 318         struct btree_iter *iter =
 319                 __bch2_trans_copy_iter(trans, src);
 320
 321         iter->ip_allocated = _THIS_IP_;
 322         return iter;
 323 }
 324
 325 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 326                                 enum btree_id, struct bpos,
 327                                 unsigned, unsigned, unsigned);
 328
 329 static inline bool btree_iter_live(struct btree_trans *trans, struct btree_iter *iter)
 330 {
 331         return (trans->iters_live & (1ULL << iter->idx)) != 0;
 332 }
 333
 334 static inline bool btree_iter_keep(struct btree_trans *trans, struct btree_iter *iter)
 335 {
 336         return btree_iter_live(trans, iter) ||
 337                 (iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT);
 338 }
 339
 340 static inline void set_btree_iter_dontneed(struct btree_trans *trans, struct btree_iter *iter)
 341 {
 342         trans->iters_touched &= ~(1ULL << iter->idx);
 343 }
 344
 345 void bch2_trans_begin(struct btree_trans *);
 346
 347 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 348 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 349 int bch2_trans_exit(struct btree_trans *);
 350
 351 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 352
 353 void bch2_fs_btree_iter_exit(struct bch_fs *);
 354 int bch2_fs_btree_iter_init(struct bch_fs *);
 355
 356 #endif /* _BCACHEFS_BTREE_ITER_H */