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 #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->level].b == b &&
  77                 btree_node_lock_seq_matches(iter, b, b->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_iter_verify(struct btree_iter *, struct btree *);
 100 void bch2_btree_trans_verify_locks(struct btree_trans *);
 101 #else
 102 static inline void bch2_btree_iter_verify(struct btree_iter *iter,
 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_trans_relock(struct btree_trans *);
 114 void bch2_trans_unlock(struct btree_trans *);
 115
 116 bool __bch2_btree_iter_upgrade(struct btree_iter *, unsigned);
 117 bool __bch2_btree_iter_upgrade_nounlock(struct btree_iter *, unsigned);
 118
 119 static inline bool bch2_btree_iter_upgrade(struct btree_iter *iter,
 120                                            unsigned new_locks_want)
 121 {
 122         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 123
 124         return iter->locks_want < new_locks_want
 125                 ? (!iter->trans->nounlock
 126                    ? __bch2_btree_iter_upgrade(iter, new_locks_want)
 127                    : __bch2_btree_iter_upgrade_nounlock(iter, new_locks_want))
 128                 : iter->uptodate <= BTREE_ITER_NEED_PEEK;
 129 }
 130
 131 void __bch2_btree_iter_downgrade(struct btree_iter *, unsigned);
 132
 133 static inline void bch2_btree_iter_downgrade(struct btree_iter *iter)
 134 {
 135         if (iter->locks_want > (iter->flags & BTREE_ITER_INTENT) ? 1 : 0)
 136                 __bch2_btree_iter_downgrade(iter, 0);
 137 }
 138
 139 void bch2_btree_iter_node_replace(struct btree_iter *, struct btree *);
 140 void bch2_btree_iter_node_drop(struct btree_iter *, struct btree *);
 141
 142 void bch2_btree_iter_reinit_node(struct btree_iter *, struct btree *);
 143
 144 int __must_check __bch2_btree_iter_traverse(struct btree_iter *);
 145
 146 static inline int __must_check
 147 bch2_btree_iter_traverse(struct btree_iter *iter)
 148 {
 149         return iter->uptodate >= BTREE_ITER_NEED_RELOCK
 150                 ? __bch2_btree_iter_traverse(iter)
 151                 : 0;
 152 }
 153
 154 int bch2_btree_iter_traverse_all(struct btree_trans *);
 155
 156 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 157 struct btree *bch2_btree_iter_next_node(struct btree_iter *, unsigned);
 158
 159 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 160 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 161
 162 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 163 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 164
 165 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 166 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 167
 168 void bch2_btree_iter_set_pos_same_leaf(struct btree_iter *, struct bpos);
 169 void __bch2_btree_iter_set_pos(struct btree_iter *, struct bpos, bool);
 170 void bch2_btree_iter_set_pos(struct btree_iter *, struct bpos);
 171
 172 static inline struct bpos btree_type_successor(enum btree_id id,
 173                                                struct bpos pos)
 174 {
 175         if (id == BTREE_ID_INODES) {
 176                 pos.inode++;
 177                 pos.offset = 0;
 178         } else if (!btree_node_type_is_extents(id)) {
 179                 pos = bkey_successor(pos);
 180         }
 181
 182         return pos;
 183 }
 184
 185 static inline struct bpos btree_type_predecessor(enum btree_id id,
 186                                                struct bpos pos)
 187 {
 188         if (id == BTREE_ID_INODES) {
 189                 --pos.inode;
 190                 pos.offset = 0;
 191         } else {
 192                 pos = bkey_predecessor(pos);
 193         }
 194
 195         return pos;
 196 }
 197
 198 static inline int __btree_iter_cmp(enum btree_id id,
 199                                    struct bpos pos,
 200                                    const struct btree_iter *r)
 201 {
 202         if (id != r->btree_id)
 203                 return id < r->btree_id ? -1 : 1;
 204         return bkey_cmp(pos, r->pos);
 205 }
 206
 207 static inline int btree_iter_cmp(const struct btree_iter *l,
 208                                  const struct btree_iter *r)
 209 {
 210         return __btree_iter_cmp(l->btree_id, l->pos, r);
 211 }
 212
 213 /*
 214  * Unlocks before scheduling
 215  * Note: does not revalidate iterator
 216  */
 217 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 218 {
 219         if (need_resched() || race_fault()) {
 220                 bch2_trans_unlock(trans);
 221                 schedule();
 222                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 223         } else {
 224                 return 0;
 225         }
 226 }
 227
 228 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 229                               _locks_want, _depth, _flags, _b)          \
 230         for (iter = bch2_trans_get_node_iter((_trans), (_btree_id),     \
 231                                 _start, _locks_want, _depth, _flags),   \
 232              _b = bch2_btree_iter_peek_node(_iter);                     \
 233              (_b);                                                      \
 234              (_b) = bch2_btree_iter_next_node(_iter, _depth))
 235
 236 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 237                             _flags, _b)                                 \
 238         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 239                               0, 0, _flags, _b)
 240
 241 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 242                                                      unsigned flags)
 243 {
 244         return flags & BTREE_ITER_SLOTS
 245                 ? bch2_btree_iter_peek_slot(iter)
 246                 : bch2_btree_iter_peek(iter);
 247 }
 248
 249 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 250                                                      unsigned flags)
 251 {
 252         return flags & BTREE_ITER_SLOTS
 253                 ? bch2_btree_iter_next_slot(iter)
 254                 : bch2_btree_iter_next(iter);
 255 }
 256
 257 static inline int bkey_err(struct bkey_s_c k)
 258 {
 259         return PTR_ERR_OR_ZERO(k.k);
 260 }
 261
 262 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 263                            _start, _flags, _k, _ret)                    \
 264         for ((_ret) = PTR_ERR_OR_ZERO((_iter) =                         \
 265                         bch2_trans_get_iter((_trans), (_btree_id),      \
 266                                             (_start), (_flags))) ?:     \
 267                       PTR_ERR_OR_ZERO(((_k) =                           \
 268                         __bch2_btree_iter_peek(_iter, _flags)).k);      \
 269              !_ret && (_k).k;                                           \
 270              (_ret) = PTR_ERR_OR_ZERO(((_k) =                           \
 271                         __bch2_btree_iter_next(_iter, _flags)).k))
 272
 273 #define for_each_btree_key_continue(_iter, _flags, _k, _ret)            \
 274         for ((_k) = __bch2_btree_iter_peek(_iter, _flags);              \
 275              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 276              (_k) = __bch2_btree_iter_next(_iter, _flags))
 277
 278 /* new multiple iterator interface: */
 279
 280 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);
 281 int bch2_trans_iter_free(struct btree_trans *, struct btree_iter *);
 282
 283 void bch2_trans_unlink_iters(struct btree_trans *);
 284
 285 struct btree_iter *bch2_trans_get_iter(struct btree_trans *, enum btree_id,
 286                                        struct bpos, unsigned);
 287 struct btree_iter *bch2_trans_copy_iter(struct btree_trans *,
 288                                         struct btree_iter *);
 289 struct btree_iter *bch2_trans_get_node_iter(struct btree_trans *,
 290                                 enum btree_id, struct bpos,
 291                                 unsigned, unsigned, unsigned);
 292
 293 #define TRANS_RESET_NOTRAVERSE          (1 << 0)
 294
 295 void bch2_trans_reset(struct btree_trans *, unsigned);
 296
 297 static inline void bch2_trans_begin(struct btree_trans *trans)
 298 {
 299         return bch2_trans_reset(trans, 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 void bch2_fs_btree_iter_exit(struct bch_fs *);
 307 int bch2_fs_btree_iter_init(struct bch_fs *);
 308
 309 #endif /* _BCACHEFS_BTREE_ITER_H */