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 bool __iter_has_node(const struct btree_iter *iter,
  75                                    const struct btree *b)
  76 {
  77         return iter->l[b->c.level].b == b &&
  78                 btree_node_lock_seq_matches(iter, b, b->c.level);
  79 }
  80
  81 static inline struct btree_iter *
  82 __trans_next_iter_with_node(struct btree_trans *trans, struct btree *b,
  83                             unsigned idx)
  84 {
  85         struct btree_iter *iter = __trans_next_iter(trans, idx);
  86
  87         while (iter && !__iter_has_node(iter, b))
  88                 iter = __trans_next_iter(trans, iter->idx + 1);
  89
  90         return iter;
  91 }
  92
  93 #define trans_for_each_iter_with_node(_trans, _b, _iter)                \
  94         for (_iter = __trans_next_iter_with_node((_trans), (_b), 0);    \
  95              (_iter);                                                   \
  96              _iter = __trans_next_iter_with_node((_trans), (_b),        \
  97                                                  (_iter)->idx + 1))
  98
  99 #ifdef CONFIG_BCACHEFS_DEBUG
 100 void bch2_btree_trans_verify_iters(struct btree_trans *, struct btree *);
 101 void bch2_btree_trans_verify_locks(struct btree_trans *);
 102 #else
 103 static inline void bch2_btree_trans_verify_iters(struct btree_trans *trans,
 104                                                  struct btree *b) {}
 105 static inline void bch2_btree_trans_verify_locks(struct btree_trans *iter) {}
 106 #endif
 107
 108 void bch2_btree_iter_fix_key_modified(struct btree_iter *, struct btree *,
 109                                            struct bkey_packed *);
 110 void bch2_btree_node_iter_fix(struct btree_iter *, struct btree *,
 111                               struct btree_node_iter *, struct bkey_packed *,
 112                               unsigned, unsigned);
 113
 114 bool bch2_btree_iter_relock(struct btree_iter *, unsigned long);
 115
 116 bool bch2_trans_relock(struct btree_trans *);
 117 void bch2_trans_unlock(struct btree_trans *);
 118
 119 bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
 120
 121 static inline bool bch2_btree_iter_upgrade(struct btree_iter *iter,
 122                                            unsigned new_locks_want)
 123 {
 124         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 125
 126         return iter->locks_want < new_locks_want
 127                 ? __bch2_btree_iter_upgrade(iter, new_locks_want)
 128                 : iter->uptodate <= BTREE_ITER_NEED_PEEK;
 129 }
 130
 131 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 132
 133 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 134 {
 135         unsigned new_locks_want = iter->level + !!(iter->flags & BTREE_ITER_INTENT);
 136
 137         if (iter->locks_want > new_locks_want)
 138                 __bch2_btree_iter_downgrade(iter, new_locks_want);
 139 }
 140
 141 void bch2_trans_downgrade(struct btree_trans *);
 142
 143 void bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
 144 void bch2_btree_iter_node_drop(struct btree_iter *, struct btree *);
 145
 146 void bch2_btree_iter_reinit_node(struct btree_iter *, struct btree *);
 147
 148 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 149
 150 int bch2_btree_iter_traverse_all(struct btree_trans *);
 151
 152 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 153 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 154
 155 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 156 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 157
 158 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 159 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 160
 161 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 162 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 163 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 164
 165 bool bch2_btree_iter_advance(struct btree_iter *);
 166 bool bch2_btree_iter_rewind(struct btree_iter *);
 167
 168 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 169 {
 170         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 171                 new_pos.snapshot = iter->snapshot;
 172
 173         iter->k.type = KEY_TYPE_deleted;
 174         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 175         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 176         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 177         iter->k.size = 0;
 178         iter->should_be_locked = false;
 179 }
 180
 181 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 182 {
 183         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 184         iter->pos = bkey_start_pos(&iter->k);
 185 }
 186
 187 static inline struct btree_iter *btree_iter_child(struct btree_iter *iter)
 188 {
 189         return iter->child_idx == U8_MAX ? NULL
 190                 : iter->trans->iters + iter->child_idx;
 191 }
 192
 193 /* Sort order for locking btree iterators: */
 194 static inline int btree_iter_lock_cmp(const struct btree_iter *l,
 195                                       const struct btree_iter *r)
 196 {
 197         return   cmp_int(l->btree_id, r->btree_id) ?:
 198                 -cmp_int(btree_iter_is_cached(l), btree_iter_is_cached(r)) ?:
 199                  bkey_cmp(l->real_pos, r->real_pos);
 200 }
 201
 202 /*
 203  * Unlocks before scheduling
 204  * Note: does not revalidate iterator
 205  */
 206 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 207 {
 208         if (need_resched() || race_fault()) {
 209                 bch2_trans_unlock(trans);
 210                 schedule();
 211                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 212         } else {
 213                 return 0;
 214         }
 215 }
 216
 217 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 218                               _locks_want, _depth, _flags, _b)          \
 219         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 220                                 _start, _locks_want, _depth, _flags),   \
 221              _b = bch2_btree_iter_peek_node(_iter);                     \
 222              (_b);                                                      \
 223              (_b) = bch2_btree_iter_next_node(_iter))
 224
 225 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 226                             _flags, _b)                                 \
 227         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 228                               0, 0, _flags, _b)
 229
 230 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 231                                                      unsigned flags)
 232 {
 233         return flags & BTREE_ITER_SLOTS
 234                 ? bch2_btree_iter_peek_slot(iter)
 235                 : bch2_btree_iter_peek(iter);
 236 }
 237
 238 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 239                                                      unsigned flags)
 240 {
 241         return flags & BTREE_ITER_SLOTS
 242                 ? bch2_btree_iter_next_slot(iter)
 243                 : bch2_btree_iter_next(iter);
 244 }
 245
 246 static inline int bkey_err(struct bkey_s_c k)
 247 {
 248         return PTR_ERR_OR_ZERO(k.k);
 249 }
 250
 251 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 252                            _start, _flags, _k, _ret)                    \
 253         for ((_iter) = bch2_trans_get_iter((_trans), (_btree_id),       \
 254                                            (_start), (_flags)),         \
 255              (_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 256              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 257              (_k) = __bch2_btree_iter_next(_iter, _flags))
 258
 259 #define for_each_btree_key_continue(_iter, _flags, _k, _ret)            \
 260         for ((_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 261              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 262              (_k) = __bch2_btree_iter_next(_iter, _flags))
 263
 264 /* new multiple iterator interface: */
 265
 266 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
 267 int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
 268
 269 void bch2_trans_unlink_iters(struct btree_trans *);
 270
 271 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
 272                                          struct bpos, unsigned,
 273                                          unsigned, unsigned);
 274
 275 static inline struct btree_iter *
 276 bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
 277                     struct bpos pos, unsigned flags)
 278 {
 279         struct btree_iter *iter =
 280                 __bch2_trans_get_iter(trans, btree_id, pos,
 281                                       (flags & BTREE_ITER_INTENT) != 0, 0,
 282                                       flags);
 283         iter->ip_allocated = _THIS_IP_;
 284         return iter;
 285 }
 286
 287 struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *,
 288                                         struct btree_iter *);
 289 static inline struct btree_iter *
 290 bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src)
 291 {
 292         struct btree_iter *iter =
 293                 __bch2_trans_copy_iter(trans, src);
 294
 295         iter->ip_allocated = _THIS_IP_;
 296         return iter;
 297 }
 298
 299 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 300                                 enum btree_id, struct bpos,
 301                                 unsigned, unsigned, unsigned);
 302
 303 static inline bool btree_iter_live(struct btree_trans *trans, struct btree_iter *iter)
 304 {
 305         return (trans->iters_live & (1ULL << iter->idx)) != 0;
 306 }
 307
 308 static inline bool btree_iter_keep(struct btree_trans *trans, struct btree_iter *iter)
 309 {
 310         return btree_iter_live(trans, iter) ||
 311                 (iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT);
 312 }
 313
 314 static inline void set_btree_iter_dontneed(struct btree_trans *trans, struct btree_iter *iter)
 315 {
 316         trans->iters_touched &= ~(1ULL << iter->idx);
 317 }
 318
 319 #define TRANS_RESET_NOTRAVERSE          (1 << 0)
 320 #define TRANS_RESET_NOUNLOCK            (1 << 1)
 321
 322 void bch2_trans_reset(struct btree_trans *, unsigned);
 323
 324 /**
 325  * bch2_trans_begin() - ensure lock consistency of transaction on retry
 326  * @trans: transaction to prepare
 327  *
 328  * Ensure lock ordering is correct before potentially retrying a transaction
 329  * after a failed trylock.
 330  */
 331 static inline void bch2_trans_begin(struct btree_trans *trans)
 332 {
 333         return bch2_trans_reset(trans, 0);
 334 }
 335
 336 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 337 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 338 int bch2_trans_exit(struct btree_trans *);
 339
 340 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 341
 342 void bch2_fs_btree_iter_exit(struct bch_fs *);
 343 int bch2_fs_btree_iter_init(struct bch_fs *);
 344
 345 #endif /* _BCACHEFS_BTREE_ITER_H */