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 = trans->iters_linked >> idx;
  55         if (!l)
  56                 return NULL;
  57
  58         idx += __ffs64(l);
  59         EBUG_ON(trans->iters[idx].idx != idx);
  60         return &trans->iters[idx];
  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->c.level].b == b &&
  72                 btree_node_lock_seq_matches(iter, b, b->c.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_trans_verify_iters(struct btree_trans *, struct btree *);
  95 void bch2_btree_trans_verify_locks(struct btree_trans *);
  96 #else
  97 static inline void bch2_btree_trans_verify_iters(struct btree_trans *trans,
  98                                                  struct btree *b) {}
  99 static inline void bch2_btree_trans_verify_locks(struct btree_trans *iter) {}
 100 #endif
 101
 102 void bch2_btree_iter_fix_key_modified(struct btree_iter *, struct btree *,
 103                                            struct bkey_packed *);
 104 void bch2_btree_node_iter_fix(struct btree_iter *, struct btree *,
 105                               struct btree_node_iter *, struct bkey_packed *,
 106                               unsigned, unsigned);
 107
 108 bool bch2_btree_iter_relock(struct btree_iter *, bool);
 109 bool bch2_trans_relock(struct btree_trans *);
 110 void bch2_trans_unlock(struct btree_trans *);
 111
 112 bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
 113 bool __bch2_btree_iter_upgrade_nounlock(struct btree_iter *, unsigned);
 114
 115 static inline bool bch2_btree_iter_upgrade(struct btree_iter *iter,
 116                                            unsigned new_locks_want)
 117 {
 118         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 119
 120         return iter->locks_want < new_locks_want
 121                 ? (!iter->trans->nounlock
 122                    ? __bch2_btree_iter_upgrade(iter, new_locks_want)
 123                    : __bch2_btree_iter_upgrade_nounlock(iter, new_locks_want))
 124                 : iter->uptodate <= BTREE_ITER_NEED_PEEK;
 125 }
 126
 127 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 128
 129 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 130 {
 131         if (iter->locks_want > (iter->flags & BTREE_ITER_INTENT) ? 1 : 0)
 132                 __bch2_btree_iter_downgrade(iter, 0);
 133 }
 134
 135 void bch2_trans_downgrade(struct btree_trans *);
 136
 137 void bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
 138 void bch2_btree_iter_node_drop(struct btree_iter *, struct btree *);
 139
 140 void bch2_btree_iter_reinit_node(struct btree_iter *, struct btree *);
 141
 142 int __must_check __bch2_btree_iter_traverse(struct btree_iter *);
 143
 144 static inline int __must_check
 145 bch2_btree_iter_traverse(struct btree_iter *iter)
 146 {
 147         return iter->uptodate >= BTREE_ITER_NEED_RELOCK
 148                 ? __bch2_btree_iter_traverse(iter)
 149                 : 0;
 150 }
 151
 152 int bch2_btree_iter_traverse_all(struct btree_trans *);
 153
 154 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 155 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 156
 157 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 158 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 159
 160 struct bkey_s_c bch2_btree_iter_peek_with_updates(struct btree_iter *);
 161 struct bkey_s_c bch2_btree_iter_next_with_updates(struct btree_iter *);
 162
 163 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 164 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 165
 166 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 167 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 168
 169 struct bkey_s_c bch2_btree_iter_peek_cached(struct btree_iter *);
 170
 171 void bch2_btree_iter_set_pos_same_leaf(struct btree_iter *, struct bpos);
 172 void __bch2_btree_iter_set_pos(struct btree_iter *, struct bpos, bool);
 173 void bch2_btree_iter_set_pos(struct btree_iter *, struct bpos);
 174
 175 /* Sort order for locking btree iterators: */
 176 static inline int btree_iter_lock_cmp(const struct btree_iter *l,
 177                                       const struct btree_iter *r)
 178 {
 179         return   cmp_int(l->btree_id, r->btree_id) ?:
 180                 -cmp_int(btree_iter_is_cached(l), btree_iter_is_cached(r)) ?:
 181                  bkey_cmp(l->pos, r->pos);
 182 }
 183
 184 /*
 185  * Unlocks before scheduling
 186  * Note: does not revalidate iterator
 187  */
 188 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 189 {
 190         if (need_resched() || race_fault()) {
 191                 bch2_trans_unlock(trans);
 192                 schedule();
 193                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 194         } else {
 195                 return 0;
 196         }
 197 }
 198
 199 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 200                               _locks_want, _depth, _flags, _b)          \
 201         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 202                                 _start, _locks_want, _depth, _flags),   \
 203              _b = bch2_btree_iter_peek_node(_iter);                     \
 204              (_b);                                                      \
 205              (_b) = bch2_btree_iter_next_node(_iter))
 206
 207 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 208                             _flags, _b)                                 \
 209         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 210                               0, 0, _flags, _b)
 211
 212 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 213                                                      unsigned flags)
 214 {
 215         if ((flags & BTREE_ITER_TYPE) == BTREE_ITER_CACHED)
 216                 return bch2_btree_iter_peek_cached(iter);
 217         else
 218                 return flags & BTREE_ITER_SLOTS
 219                         ? bch2_btree_iter_peek_slot(iter)
 220                         : bch2_btree_iter_peek(iter);
 221 }
 222
 223 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 224                                                      unsigned flags)
 225 {
 226         return flags & BTREE_ITER_SLOTS
 227                 ? bch2_btree_iter_next_slot(iter)
 228                 : bch2_btree_iter_next(iter);
 229 }
 230
 231 static inline int bkey_err(struct bkey_s_c k)
 232 {
 233         return PTR_ERR_OR_ZERO(k.k);
 234 }
 235
 236 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 237                            _start, _flags, _k, _ret)                    \
 238         for ((_iter) = bch2_trans_get_iter((_trans), (_btree_id),       \
 239                                            (_start), (_flags)),         \
 240              (_ret) = PTR_ERR_OR_ZERO(((_k) =                           \
 241                         __bch2_btree_iter_peek(_iter, _flags)).k);      \
 242              !_ret && (_k).k;                                           \
 243              (_ret) = PTR_ERR_OR_ZERO(((_k) =                           \
 244                         __bch2_btree_iter_next(_iter, _flags)).k))
 245
 246 #define for_each_btree_key_continue(_iter, _flags, _k, _ret)            \
 247         for ((_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 248              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 249              (_k) = __bch2_btree_iter_next(_iter, _flags))
 250
 251 /* new multiple iterator interface: */
 252
 253 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
 254 int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
 255
 256 void bch2_trans_unlink_iters(struct btree_trans *);
 257
 258 struct btree_iter *__bch2_trans_get_iter(struct btree_trans *, enum btree_id,
 259                                          struct bpos, unsigned);
 260
 261 static inline struct btree_iter *
 262 bch2_trans_get_iter(struct btree_trans *trans, enum btree_id btree_id,
 263                     struct bpos pos, unsigned flags)
 264 {
 265         struct btree_iter *iter =
 266                 __bch2_trans_get_iter(trans, btree_id, pos, flags);
 267         iter->ip_allocated = _THIS_IP_;
 268         return iter;
 269 }
 270
 271 struct btree_iter *__bch2_trans_copy_iter(struct btree_trans *,
 272                                         struct btree_iter *);
 273 static inline struct btree_iter *
 274 bch2_trans_copy_iter(struct btree_trans *trans, struct btree_iter *src)
 275 {
 276         struct btree_iter *iter =
 277                 __bch2_trans_copy_iter(trans, src);
 278
 279         iter->ip_allocated = _THIS_IP_;
 280         return iter;
 281 }
 282
 283 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 284                                 enum btree_id, struct bpos,
 285                                 unsigned, unsigned, unsigned);
 286
 287 #define TRANS_RESET_NOTRAVERSE          (1 << 0)
 288
 289 void bch2_trans_reset(struct btree_trans *, unsigned);
 290
 291 static inline void bch2_trans_begin(struct btree_trans *trans)
 292 {
 293         return bch2_trans_reset(trans, 0);
 294 }
 295
 296 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 297 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 298 int bch2_trans_exit(struct btree_trans *);
 299
 300 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 301
 302 void bch2_fs_btree_iter_exit(struct bch_fs *);
 303 int bch2_fs_btree_iter_init(struct bch_fs *);
 304
 305 #endif /* _BCACHEFS_BTREE_ITER_H */