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 *, bool);
 115 bool bch2_trans_relock(struct btree_trans *);
 116 void bch2_trans_unlock(struct btree_trans *);
 117
 118 bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
 119 bool __bch2_btree_iter_upgrade_nounlock(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                 ? (!iter->trans->nounlock
 128                    ? __bch2_btree_iter_upgrade(iter, new_locks_want)
 129                    : __bch2_btree_iter_upgrade_nounlock(iter, new_locks_want))
 130                 : iter->uptodate <= BTREE_ITER_NEED_PEEK;
 131 }
 132
 133 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 134
 135 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 136 {
 137         if (iter->locks_want > (iter->flags & BTREE_ITER_INTENT) ? 1 : 0)
 138                 __bch2_btree_iter_downgrade(iter, 0);
 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 static inline int __must_check
 151 bch2_btree_iter_traverse(struct btree_iter *iter)
 152 {
 153         return iter->uptodate >= BTREE_ITER_NEED_RELOCK
 154                 ? __bch2_btree_iter_traverse(iter)
 155                 : 0;
 156 }
 157
 158 int bch2_btree_iter_traverse_all(struct btree_trans *);
 159
 160 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 161 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 162
 163 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 164 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 165
 166 struct bkey_s_c bch2_btree_iter_peek_with_updates(struct btree_iter *);
 167 struct bkey_s_c bch2_btree_iter_next_with_updates(struct btree_iter *);
 168
 169 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 170 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 171
 172 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 173 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 174 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 175
 176 struct bkey_s_c bch2_btree_iter_peek_cached(struct btree_iter *);
 177
 178 bool bch2_btree_iter_advance_pos(struct btree_iter *);
 179 bool bch2_btree_iter_rewind_pos(struct btree_iter *);
 180 void bch2_btree_iter_set_pos(struct btree_iter *, struct bpos);
 181
 182 /* Sort order for locking btree iterators: */
 183 static inline int btree_iter_lock_cmp(const struct btree_iter *l,
 184                                       const struct btree_iter *r)
 185 {
 186         return   cmp_int(l->btree_id, r->btree_id) ?:
 187                 -cmp_int(btree_iter_is_cached(l), btree_iter_is_cached(r)) ?:
 188                  bkey_cmp(l->pos, r->pos);
 189 }
 190
 191 /*
 192  * Unlocks before scheduling
 193  * Note: does not revalidate iterator
 194  */
 195 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 196 {
 197         if (need_resched() || race_fault()) {
 198                 bch2_trans_unlock(trans);
 199                 schedule();
 200                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 201         } else {
 202                 return 0;
 203         }
 204 }
 205
 206 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 207                               _locks_want, _depth, _flags, _b)          \
 208         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 209                                 _start, _locks_want, _depth, _flags),   \
 210              _b = bch2_btree_iter_peek_node(_iter);                     \
 211              (_b);                                                      \
 212              (_b) = bch2_btree_iter_next_node(_iter))
 213
 214 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 215                             _flags, _b)                                 \
 216         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 217                               0, 0, _flags, _b)
 218
 219 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 220                                                      unsigned flags)
 221 {
 222         if ((flags & BTREE_ITER_TYPE) == BTREE_ITER_CACHED)
 223                 return bch2_btree_iter_peek_cached(iter);
 224         else
 225                 return flags & BTREE_ITER_SLOTS
 226                         ? bch2_btree_iter_peek_slot(iter)
 227                         : bch2_btree_iter_peek(iter);
 228 }
 229
 230 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 231                                                      unsigned flags)
 232 {
 233         return flags & BTREE_ITER_SLOTS
 234                 ? bch2_btree_iter_next_slot(iter)
 235                 : bch2_btree_iter_next(iter);
 236 }
 237
 238 static inline int bkey_err(struct bkey_s_c k)
 239 {
 240         return PTR_ERR_OR_ZERO(k.k);
 241 }
 242
 243 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 244                            _start, _flags, _k, _ret)                    \
 245         for ((_iter) = bch2_trans_get_iter((_trans), (_btree_id),       \
 246                                            (_start), (_flags)),         \
 247              (_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 248              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 249              (_k) = __bch2_btree_iter_next(_iter, _flags))
 250
 251 #define for_each_btree_key_continue(_iter, _flags, _k, _ret)            \
 252         for ((_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 253              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 254              (_k) = __bch2_btree_iter_next(_iter, _flags))
 255
 256 /* new multiple iterator interface: */
 257
 258 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
 259 int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
 260
 261 void bch2_trans_unlink_iters(struct btree_trans *);
 262
 263 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
 264                                          struct bpos, unsigned);
 265
 266 static inline struct btree_iter *
 267 bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
 268                     struct bpos pos, unsigned flags)
 269 {
 270         struct btree_iter *iter =
 271                 __bch2_trans_get_iter(trans, btree_id, pos, flags);
 272         iter->ip_allocated = _THIS_IP_;
 273         return iter;
 274 }
 275
 276 struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *,
 277                                         struct btree_iter *);
 278 static inline struct btree_iter *
 279 bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src)
 280 {
 281         struct btree_iter *iter =
 282                 __bch2_trans_copy_iter(trans, src);
 283
 284         iter->ip_allocated = _THIS_IP_;
 285         return iter;
 286 }
 287
 288 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 289                                 enum btree_id, struct bpos,
 290                                 unsigned, unsigned, unsigned);
 291
 292 static inline bool btree_iter_live(struct btree_trans *trans, struct btree_iter *iter)
 293 {
 294         return (trans->iters_live & (1ULL << iter->idx)) != 0;
 295 }
 296
 297 static inline bool btree_iter_keep(struct btree_trans *trans, struct btree_iter *iter)
 298 {
 299         return btree_iter_live(trans, iter) ||
 300                 (iter->flags & BTREE_ITER_KEEP_UNTIL_COMMIT);
 301 }
 302
 303 static inline void set_btree_iter_dontneed(struct btree_trans *trans, struct btree_iter *iter)
 304 {
 305         trans->iters_touched &= ~(1ULL << iter->idx);
 306 }
 307
 308 #define TRANS_RESET_NOTRAVERSE          (1 << 0)
 309
 310 void bch2_trans_reset(struct btree_trans *, unsigned);
 311
 312 static inline void bch2_trans_begin(struct btree_trans *trans)
 313 {
 314         return bch2_trans_reset(trans, 0);
 315 }
 316
 317 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 318 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 319 int bch2_trans_exit(struct btree_trans *);
 320
 321 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 322
 323 void bch2_fs_btree_iter_exit(struct bch_fs *);
 324 int bch2_fs_btree_iter_init(struct bch_fs *);
 325
 326 #endif /* _BCACHEFS_BTREE_ITER_H */