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
   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         unsigned idx = iter ? iter->sorted_idx : trans->nr_sorted;
  88
  89         return idx
  90                 ? trans->iters + trans->sorted[idx - 1]
  91                 : NULL;
  92 }
  93
  94 #define trans_for_each_iter_inorder(_trans, _iter, _i)                  \
  95         for (_i = 0;                                                    \
  96              ((_iter) = (_trans)->iters + trans->sorted[_i]), (_i) < (_trans)->nr_sorted;\
  97              _i++)
  98
  99 #define trans_for_each_iter_inorder_reverse(_trans, _iter, _i)          \
 100         for (_i = trans->nr_sorted - 1;                                 \
 101              ((_iter) = (_trans)->iters + trans->sorted[_i]), (_i) >= 0;\
 102              --_i)
 103
 104 static inline bool __iter_has_node(const struct btree_iter *iter,
 105                                    const struct btree *b)
 106 {
 107         return iter->l[b->c.level].b == b &&
 108                 btree_node_lock_seq_matches(iter, b, b->c.level);
 109 }
 110
 111 static inline struct btree_iter *
 112 __trans_next_iter_with_node(struct btree_trans *trans, struct btree *b,
 113                             unsigned idx)
 114 {
 115         struct btree_iter *iter = __trans_next_iter(trans, idx);
 116
 117         while (iter && !__iter_has_node(iter, b))
 118                 iter = __trans_next_iter(trans, iter->idx + 1);
 119
 120         return iter;
 121 }
 122
 123 #define trans_for_each_iter_with_node(_trans, _b, _iter)                \
 124         for (_iter = __trans_next_iter_with_node((_trans), (_b), 0);    \
 125              (_iter);                                                   \
 126              _iter = __trans_next_iter_with_node((_trans), (_b),        \
 127                                                  (_iter)->idx + 1))
 128
 129 #ifdef CONFIG_BCACHEFS_DEBUG
 130 void bch2_trans_verify_iters(struct btree_trans *, struct btree *);
 131 void bch2_trans_verify_locks(struct btree_trans *);
 132 #else
 133 static inline void bch2_trans_verify_iters(struct btree_trans *trans,
 134                                            struct btree *b) {}
 135 static inline void bch2_trans_verify_locks(struct btree_trans *iter) {}
 136 #endif
 137
 138 void bch2_btree_iter_fix_key_modified(struct btree_trans *trans,
 139                                       struct btree *, struct bkey_packed *);
 140 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_iter *,
 141                               struct btree *, struct btree_node_iter *,
 142                               struct bkey_packed *, unsigned, unsigned);
 143
 144 bool bch2_btree_iter_relock_intent(struct btree_trans *, struct btree_iter *);
 145
 146 bool bch2_trans_relock(struct btree_trans *);
 147 void bch2_trans_unlock(struct btree_trans *);
 148
 149 __always_inline
 150 static inline int btree_trans_restart(struct btree_trans *trans)
 151 {
 152         trans->restarted = true;
 153         bch2_trans_unlock(trans);
 154         return -EINTR;
 155 }
 156
 157 bool __bch2_btree_iter_upgrade(struct btree_trans *,
 158                                struct btree_iter *, unsigned);
 159
 160 static inline bool bch2_btree_iter_upgrade(struct btree_trans *trans,
 161                                            struct btree_iter *iter,
 162                                            unsigned new_locks_want)
 163 {
 164         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 165
 166         return iter->locks_want < new_locks_want
 167                 ? __bch2_btree_iter_upgrade(trans, iter, new_locks_want)
 168                 : iter->uptodate == BTREE_ITER_UPTODATE;
 169 }
 170
 171 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 172
 173 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 174 {
 175         unsigned new_locks_want = iter->level + !!(iter->flags & BTREE_ITER_INTENT);
 176
 177         if (iter->locks_want > new_locks_want)
 178                 __bch2_btree_iter_downgrade(iter, new_locks_want);
 179 }
 180
 181 void bch2_trans_downgrade(struct btree_trans *);
 182
 183 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
 184 void bch2_trans_node_drop(struct btree_trans *, struct btree *);
 185 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 186
 187 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 188
 189 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 190 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 191
 192 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 193 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 194
 195 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 196 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 197
 198 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 199 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 200 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 201
 202 bool bch2_btree_iter_advance(struct btree_iter *);
 203 bool bch2_btree_iter_rewind(struct btree_iter *);
 204
 205 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 206 {
 207         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 208                 new_pos.snapshot = iter->snapshot;
 209
 210         iter->k.type = KEY_TYPE_deleted;
 211         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 212         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 213         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 214         iter->k.size = 0;
 215         iter->should_be_locked = false;
 216 }
 217
 218 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 219 {
 220         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 221         iter->pos = bkey_start_pos(&iter->k);
 222 }
 223
 224 static inline struct btree_iter *idx_to_btree_iter(struct btree_trans *trans, unsigned idx)
 225 {
 226         return idx != U8_MAX ? trans->iters + idx : NULL;
 227 }
 228
 229 static inline struct btree_iter *btree_iter_child(struct btree_trans *trans,
 230                                                   struct btree_iter *iter)
 231 {
 232         return idx_to_btree_iter(trans, iter->child_idx);
 233 }
 234
 235 /*
 236  * Unlocks before scheduling
 237  * Note: does not revalidate iterator
 238  */
 239 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 240 {
 241         if (need_resched() || race_fault()) {
 242                 bch2_trans_unlock(trans);
 243                 schedule();
 244                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 245         } else {
 246                 return 0;
 247         }
 248 }
 249
 250 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 251                               _locks_want, _depth, _flags, _b)          \
 252         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 253                                 _start, _locks_want, _depth, _flags),   \
 254              _b = bch2_btree_iter_peek_node(_iter);                     \
 255              (_b);                                                      \
 256              (_b) = bch2_btree_iter_next_node(_iter))
 257
 258 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 259                             _flags, _b)                                 \
 260         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 261                               0, 0, _flags, _b)
 262
 263 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 264                                                      unsigned flags)
 265 {
 266         return flags & BTREE_ITER_SLOTS
 267                 ? bch2_btree_iter_peek_slot(iter)
 268                 : bch2_btree_iter_peek(iter);
 269 }
 270
 271 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 272                                                      unsigned flags)
 273 {
 274         return flags & BTREE_ITER_SLOTS
 275                 ? bch2_btree_iter_next_slot(iter)
 276                 : bch2_btree_iter_next(iter);
 277 }
 278
 279 static inline int bkey_err(struct bkey_s_c k)
 280 {
 281         return PTR_ERR_OR_ZERO(k.k);
 282 }
 283
 284 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 285                            _start, _flags, _k, _ret)                    \
 286         for ((_iter) = bch2_trans_get_iter((_trans), (_btree_id),       \
 287                                            (_start), (_flags)),         \
 288              (_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 289              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 290              (_k) = __bch2_btree_iter_next(_iter, _flags))
 291
 292 #define for_each_btree_key_continue(_iter, _flags, _k, _ret)            \
 293         for ((_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 294              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 295              (_k) = __bch2_btree_iter_next(_iter, _flags))
 296
 297 /* new multiple iterator interface: */
 298
 299 void bch2_dump_trans_iters_updates(struct btree_trans *);
 300
 301 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
 302 int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
 303
 304 void bch2_trans_unlink_iters(struct btree_trans *);
 305
 306 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
 307                                          struct bpos, unsigned,
 308                                          unsigned, unsigned);
 309
 310 static inline struct btree_iter *
 311 bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
 312                     struct bpos pos, unsigned flags)
 313 {
 314         struct btree_iter *iter =
 315                 __bch2_trans_get_iter(trans, btree_id, pos,
 316                                       (flags & BTREE_ITER_INTENT) != 0, 0,
 317                                       flags);
 318         iter->ip_allocated = _THIS_IP_;
 319         return iter;
 320 }
 321
 322 struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *,
 323                                           struct btree_iter *);
 324 static inline struct btree_iter *
 325 bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src)
 326 {
 327         struct btree_iter *iter =
 328                 __bch2_trans_copy_iter(trans, src);
 329
 330         iter->ip_allocated = _THIS_IP_;
 331         return iter;
 332 }
 333
 334 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 335                                 enum btree_id, struct bpos,
 336                                 unsigned, unsigned, unsigned);
 337
 338 static inline bool btree_iter_live(struct btree_trans *trans, struct btree_iter *iter)
 339 {
 340         return (trans->iters_live & (1ULL << iter->idx)) != 0;
 341 }
 342
 343 static inline bool btree_iter_keep(struct btree_trans *trans, struct btree_iter *iter)
 344 {
 345         return btree_iter_live(trans, iter) ||
 346                 (iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT);
 347 }
 348
 349 static inline void set_btree_iter_dontneed(struct btree_trans *trans, struct btree_iter *iter)
 350 {
 351         trans->iters_touched &= ~(1ULL << iter->idx);
 352 }
 353
 354 void bch2_trans_begin(struct btree_trans *);
 355
 356 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 357 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 358 int bch2_trans_exit(struct btree_trans *);
 359
 360 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 361
 362 void bch2_fs_btree_iter_exit(struct bch_fs *);
 363 int bch2_fs_btree_iter_init(struct bch_fs *);
 364
 365 #endif /* _BCACHEFS_BTREE_ITER_H */