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 #define trans_for_each_iter_all(_trans, _iter)                          \
  52         for (_iter = (_trans)->iters;                                   \
  53              _iter < (_trans)->iters + (_trans)->nr_iters;              \
  54              _iter++)
  55
  56 static inline struct btree_iter *
  57 __trans_next_iter(struct btree_trans *trans, unsigned idx)
  58 {
  59         EBUG_ON(idx < trans->nr_iters && trans->iters[idx].idx != idx);
  60
  61         for (; idx < trans->nr_iters; idx++)
  62                 if (trans->iters_linked & (1ULL << idx))
  63                         return &trans->iters[idx];
  64
  65         return NULL;
  66 }
  67
  68 #define trans_for_each_iter(_trans, _iter)                              \
  69         for (_iter = __trans_next_iter((_trans), 0);                    \
  70              (_iter);                                                   \
  71              _iter = __trans_next_iter((_trans), (_iter)->idx + 1))
  72
  73 static inline bool __iter_has_node(const struct btree_iter *iter,
  74                                    const struct btree *b)
  75 {
  76         return iter->l[b->c.level].b == b &&
  77                 btree_node_lock_seq_matches(iter, b, b->c.level);
  78 }
  79
  80 static inline struct btree_iter *
  81 __trans_next_iter_with_node(struct btree_trans *trans, struct btree *b,
  82                             unsigned idx)
  83 {
  84         struct btree_iter *iter = __trans_next_iter(trans, idx);
  85
  86         while (iter && !__iter_has_node(iter, b))
  87                 iter = __trans_next_iter(trans, iter->idx + 1);
  88
  89         return iter;
  90 }
  91
  92 #define trans_for_each_iter_with_node(_trans, _b, _iter)                \
  93         for (_iter = __trans_next_iter_with_node((_trans), (_b), 0);    \
  94              (_iter);                                                   \
  95              _iter = __trans_next_iter_with_node((_trans), (_b),        \
  96                                                  (_iter)->idx + 1))
  97
  98 #ifdef CONFIG_BCACHEFS_DEBUG
  99 void bch2_btree_trans_verify_iters(struct btree_trans *, struct btree *);
 100 void bch2_btree_trans_verify_locks(struct btree_trans *);
 101 #else
 102 static inline void bch2_btree_trans_verify_iters(struct btree_trans *trans,
 103                                                  struct btree *b) {}
 104 static inline void bch2_btree_trans_verify_locks(struct btree_trans *iter) {}
 105 #endif
 106
 107 void bch2_btree_iter_fix_key_modified(struct btree_iter *, struct btree *,
 108                                            struct bkey_packed *);
 109 void bch2_btree_node_iter_fix(struct btree_iter *, struct btree *,
 110                               struct btree_node_iter *, struct bkey_packed *,
 111                               unsigned, unsigned);
 112
 113 bool bch2_btree_iter_relock(struct btree_iter *, bool);
 114 bool bch2_trans_relock(struct btree_trans *);
 115 void bch2_trans_unlock(struct btree_trans *);
 116
 117 bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
 118 bool __bch2_btree_iter_upgrade_nounlock(struct btree_iter *, unsigned);
 119
 120 static inline bool bch2_btree_iter_upgrade(struct btree_iter *iter,
 121                                            unsigned new_locks_want)
 122 {
 123         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 124
 125         return iter->locks_want < new_locks_want
 126                 ? (!iter->trans->nounlock
 127                    ? __bch2_btree_iter_upgrade(iter, new_locks_want)
 128                    : __bch2_btree_iter_upgrade_nounlock(iter, new_locks_want))
 129                 : iter->uptodate <= BTREE_ITER_NEED_PEEK;
 130 }
 131
 132 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 133
 134 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 135 {
 136         if (iter->locks_want > (iter->flags & BTREE_ITER_INTENT) ? 1 : 0)
 137                 __bch2_btree_iter_downgrade(iter, 0);
 138 }
 139
 140 void bch2_trans_downgrade(struct btree_trans *);
 141
 142 void bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
 143 void bch2_btree_iter_node_drop(struct btree_iter *, struct btree *);
 144
 145 void bch2_btree_iter_reinit_node(struct btree_iter *, struct btree *);
 146
 147 int __must_check __bch2_btree_iter_traverse(struct btree_iter *);
 148
 149 static inline int __must_check
 150 bch2_btree_iter_traverse(struct btree_iter *iter)
 151 {
 152         return iter->uptodate >= BTREE_ITER_NEED_RELOCK
 153                 ? __bch2_btree_iter_traverse(iter)
 154                 : 0;
 155 }
 156
 157 int bch2_btree_iter_traverse_all(struct btree_trans *);
 158
 159 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 160 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 161
 162 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 163 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 164
 165 struct bkey_s_c bch2_btree_iter_peek_with_updates(struct btree_iter *);
 166 struct bkey_s_c bch2_btree_iter_next_with_updates(struct btree_iter *);
 167
 168 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 169 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 170
 171 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 172 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 173
 174 struct bkey_s_c bch2_btree_iter_peek_cached(struct btree_iter *);
 175
 176 void bch2_btree_iter_set_pos_same_leaf(struct btree_iter *, struct bpos);
 177 void __bch2_btree_iter_set_pos(struct btree_iter *, struct bpos, bool);
 178 void bch2_btree_iter_set_pos(struct btree_iter *, struct bpos);
 179
 180 static inline int btree_iter_cmp(const struct btree_iter *l,
 181                                  const struct btree_iter *r)
 182 {
 183         return   cmp_int(l->btree_id, r->btree_id) ?:
 184                 -cmp_int(btree_iter_type(l), btree_iter_type(r)) ?:
 185                  bkey_cmp(l->pos, r->pos);
 186 }
 187
 188 /*
 189  * Unlocks before scheduling
 190  * Note: does not revalidate iterator
 191  */
 192 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 193 {
 194         if (need_resched() || race_fault()) {
 195                 bch2_trans_unlock(trans);
 196                 schedule();
 197                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 198         } else {
 199                 return 0;
 200         }
 201 }
 202
 203 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 204                               _locks_want, _depth, _flags, _b)          \
 205         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 206                                 _start, _locks_want, _depth, _flags),   \
 207              _b = bch2_btree_iter_peek_node(_iter);                     \
 208              (_b);                                                      \
 209              (_b) = bch2_btree_iter_next_node(_iter))
 210
 211 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 212                             _flags, _b)                                 \
 213         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 214                               0, 0, _flags, _b)
 215
 216 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 217                                                      unsigned flags)
 218 {
 219         if ((flags & BTREE_ITER_TYPE) == BTREE_ITER_CACHED)
 220                 return bch2_btree_iter_peek_cached(iter);
 221         else
 222                 return flags & BTREE_ITER_SLOTS
 223                         ? bch2_btree_iter_peek_slot(iter)
 224                         : bch2_btree_iter_peek(iter);
 225 }
 226
 227 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 228                                                      unsigned flags)
 229 {
 230         return flags & BTREE_ITER_SLOTS
 231                 ? bch2_btree_iter_next_slot(iter)
 232                 : bch2_btree_iter_next(iter);
 233 }
 234
 235 static inline int bkey_err(struct bkey_s_c k)
 236 {
 237         return PTR_ERR_OR_ZERO(k.k);
 238 }
 239
 240 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 241                            _start, _flags, _k, _ret)                    \
 242         for ((_ret) = PTR_ERR_OR_ZERO((_iter) =                         \
 243                         bch2_trans_get_iter((_trans), (_btree_id),      \
 244                                             (_start), (_flags))) ?:     \
 245                       PTR_ERR_OR_ZERO(((_k) =                           \
 246                         __bch2_btree_iter_peek(_iter, _flags)).k);      \
 247              !_ret && (_k).k;                                           \
 248              (_ret) = PTR_ERR_OR_ZERO(((_k) =                           \
 249                         __bch2_btree_iter_next(_iter, _flags)).k))
 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
 273         if (!IS_ERR(iter))
 274                 iter->ip_allocated = _THIS_IP_;
 275         return iter;
 276 }
 277
 278 struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *,
 279                                         struct btree_iter *);
 280 static inline struct btree_iter *
 281 bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src)
 282 {
 283         struct btree_iter *iter =
 284                 __bch2_trans_copy_iter(trans, src);
 285
 286         if (!IS_ERR(iter))
 287                 iter->ip_allocated = _THIS_IP_;
 288         return iter;
 289
 290 }
 291
 292 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 293                                 enum btree_id, struct bpos,
 294                                 unsigned, unsigned, unsigned);
 295
 296 #define TRANS_RESET_NOTRAVERSE          (1 << 0)
 297
 298 void bch2_trans_reset(struct btree_trans *, unsigned);
 299
 300 static inline void bch2_trans_begin(struct btree_trans *trans)
 301 {
 302         return bch2_trans_reset(trans, 0);
 303 }
 304
 305 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 306 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 307 int bch2_trans_exit(struct btree_trans *);
 308
 309 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 310
 311 void bch2_fs_btree_iter_exit(struct bch_fs *);
 312 int bch2_fs_btree_iter_init(struct bch_fs *);
 313
 314 #endif /* _BCACHEFS_BTREE_ITER_H */