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->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->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         EBUG_ON(idx < trans->nr_iters && trans->iters[idx].idx != idx);
  55
  56         for (; idx < trans->nr_iters; idx++)
  57                 if (trans->iters_linked & (1ULL << idx))
  58                         return &trans->iters[idx];
  59
  60         return NULL;
  61 }
  62
  63 #define trans_for_each_iter(_trans, _iter)                              \
  64         for (_iter = __trans_next_iter((_trans), 0);                    \
  65              (_iter);                                                   \
  66              _iter = __trans_next_iter((_trans), (_iter)->idx + 1))
  67
  68 static inline bool __iter_has_node(const struct btree_iter *iter,
  69                                    const struct btree *b)
  70 {
  71         return iter->l[b->level].b == b &&
  72                 btree_node_lock_seq_matches(iter, b, b->level);
  73 }
  74
  75 static inline struct btree_iter *
  76 __trans_next_iter_with_node(struct btree_trans *trans, struct btree *b,
  77                             unsigned idx)
  78 {
  79         struct btree_iter *iter = __trans_next_iter(trans, idx);
  80
  81         while (iter && !__iter_has_node(iter, b))
  82                 iter = __trans_next_iter(trans, iter->idx + 1);
  83
  84         return iter;
  85 }
  86
  87 #define trans_for_each_iter_with_node(_trans, _b, _iter)                \
  88         for (_iter = __trans_next_iter_with_node((_trans), (_b), 0);    \
  89              (_iter);                                                   \
  90              _iter = __trans_next_iter_with_node((_trans), (_b),        \
  91                                                  (_iter)->idx + 1))
  92
  93 #ifdef CONFIG_BCACHEFS_DEBUG
  94 void bch2_btree_iter_verify(struct btree_iter *, struct btree *);
  95 void bch2_btree_trans_verify_locks(struct btree_trans *);
  96 #else
  97 static inline void bch2_btree_iter_verify(struct btree_iter *iter,
  98                                           struct btree *b) {}
  99 static inline void bch2_btree_trans_verify_locks(struct btree_trans *iter) {}
 100 #endif
 101
 102 void bch2_btree_node_iter_fix(struct btree_iter *, struct btree *,
 103                               struct btree_node_iter *, struct bkey_packed *,
 104                               unsigned, unsigned);
 105
 106 bool bch2_trans_relock(struct btree_trans *);
 107 void bch2_trans_unlock(struct btree_trans *);
 108
 109 bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
 110 bool __bch2_btree_iter_upgrade_nounlock(struct btree_iter *, unsigned);
 111
 112 static inline bool bch2_btree_iter_upgrade(struct btree_iter *iter,
 113                                            unsigned new_locks_want)
 114 {
 115         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 116
 117         return iter->locks_want < new_locks_want
 118                 ? (!iter->trans->nounlock
 119                    ? __bch2_btree_iter_upgrade(iter, new_locks_want)
 120                    : __bch2_btree_iter_upgrade_nounlock(iter, new_locks_want))
 121                 : iter->uptodate <= BTREE_ITER_NEED_PEEK;
 122 }
 123
 124 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 125
 126 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 127 {
 128         if (iter->locks_want > (iter->flags & BTREE_ITER_INTENT) ? 1 : 0)
 129                 __bch2_btree_iter_downgrade(iter, 0);
 130 }
 131
 132 void bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
 133 void bch2_btree_iter_node_drop(struct btree_iter *, struct btree *);
 134
 135 void bch2_btree_iter_reinit_node(struct btree_iter *, struct btree *);
 136
 137 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 138 int bch2_btree_iter_traverse_all(struct btree_trans *);
 139
 140 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 141 struct btree *bch2_btree_iter_next_node(struct btree_iter *, unsigned);
 142
 143 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 144 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 145 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 146
 147 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 148 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 149
 150 void bch2_btree_iter_set_pos_same_leaf(struct btree_iter *, struct bpos);
 151 void bch2_btree_iter_set_pos(struct btree_iter *, struct bpos);
 152
 153 static inline struct bpos btree_type_successor(enum btree_id id,
 154                                                struct bpos pos)
 155 {
 156         if (id == BTREE_ID_INODES) {
 157                 pos.inode++;
 158                 pos.offset = 0;
 159         } else if (!btree_node_type_is_extents(id)) {
 160                 pos = bkey_successor(pos);
 161         }
 162
 163         return pos;
 164 }
 165
 166 static inline struct bpos btree_type_predecessor(enum btree_id id,
 167                                                struct bpos pos)
 168 {
 169         if (id == BTREE_ID_INODES) {
 170                 --pos.inode;
 171                 pos.offset = 0;
 172         } else {
 173                 pos = bkey_predecessor(pos);
 174         }
 175
 176         return pos;
 177 }
 178
 179 static inline int __btree_iter_cmp(enum btree_id id,
 180                                    struct bpos pos,
 181                                    const struct btree_iter *r)
 182 {
 183         if (id != r->btree_id)
 184                 return id < r->btree_id ? -1 : 1;
 185         return bkey_cmp(pos, r->pos);
 186 }
 187
 188 static inline int btree_iter_cmp(const struct btree_iter *l,
 189                                  const struct btree_iter *r)
 190 {
 191         return __btree_iter_cmp(l->btree_id, l->pos, r);
 192 }
 193
 194 /*
 195  * Unlocks before scheduling
 196  * Note: does not revalidate iterator
 197  */
 198 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 199 {
 200         if (need_resched() || race_fault()) {
 201                 bch2_trans_unlock(trans);
 202                 schedule();
 203                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 204         } else {
 205                 return 0;
 206         }
 207 }
 208
 209 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 210                               _locks_want, _depth, _flags, _b)          \
 211         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 212                                 _start, _locks_want, _depth, _flags),   \
 213              _b = bch2_btree_iter_peek_node(_iter);                     \
 214              (_b);                                                      \
 215              (_b) = bch2_btree_iter_next_node(_iter, _depth))
 216
 217 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 218                             _flags, _b)                                 \
 219         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 220                               0, 0, _flags, _b)
 221
 222 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 223                                                      unsigned flags)
 224 {
 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 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 239                            _start, _flags, _k, _ret)                    \
 240         for ((_ret) = PTR_ERR_OR_ZERO((_iter) =                         \
 241                         bch2_trans_get_iter((_trans), (_btree_id),      \
 242                                             (_start), (_flags))) ?:     \
 243                       PTR_ERR_OR_ZERO(((_k) =                           \
 244                         __bch2_btree_iter_peek(_iter, _flags)).k);      \
 245              !_ret && (_k).k;                                           \
 246              (_ret) = PTR_ERR_OR_ZERO(((_k) =                           \
 247                         __bch2_btree_iter_next(_iter, _flags)).k))
 248
 249 #define for_each_btree_key_continue(_iter, _flags, _k)                  \
 250         for ((_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 251              !IS_ERR_OR_NULL((_k).k);                                   \
 252              (_k) = __bch2_btree_iter_next(_iter, _flags))
 253
 254 static inline int bkey_err(struct bkey_s_c k)
 255 {
 256         return PTR_ERR_OR_ZERO(k.k);
 257 }
 258
 259 /* new multiple iterator interface: */
 260
 261 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
 262 int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
 263 int bch2_trans_iter_free_on_commit(struct btree_trans *, struct btree_iter *);
 264
 265 void bch2_trans_unlink_iters(struct btree_trans *, u64);
 266
 267 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
 268                                          struct bpos, unsigned, u64);
 269 struct btree_iter *bch2_trans_copy_iter(struct btree_trans *,
 270                                         struct btree_iter *);
 271
 272 static __always_inline u64 __btree_iter_id(void)
 273 {
 274         u64 ret = 0;
 275
 276         ret <<= 32;
 277         ret |= _RET_IP_ & U32_MAX;
 278         ret <<= 32;
 279         ret |= _THIS_IP_ & U32_MAX;
 280         return ret;
 281 }
 282
 283 static __always_inline struct btree_iter *
 284 bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
 285                     struct bpos pos, unsigned flags)
 286 {
 287         return __bch2_trans_get_iter(trans, btree_id, pos, flags,
 288                                      __btree_iter_id());
 289 }
 290
 291 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 292                                 enum btree_id, struct bpos,
 293                                 unsigned, unsigned, unsigned);
 294
 295 void bch2_trans_begin(struct btree_trans *);
 296
 297 static inline void bch2_trans_begin_updates(struct btree_trans *trans)
 298 {
 299         trans->nr_updates = 0;
 300 }
 301
 302 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 303 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 304 int bch2_trans_exit(struct btree_trans *);
 305
 306 #endif /* _BCACHEFS_BTREE_ITER_H */