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_path_get(struct btree_path *path, bool intent)
   9 {
  10         path->ref++;
  11         path->intent_ref += intent;
  12 }
  13
  14 static inline bool __btree_path_put(struct btree_path *path, bool intent)
  15 {
  16         EBUG_ON(!path->ref);
  17         EBUG_ON(!path->intent_ref && intent);
  18         path->intent_ref -= intent;
  19         return --path->ref == 0;
  20 }
  21
  22 static inline void btree_path_set_dirty(struct btree_path *path,
  23                                         enum btree_path_uptodate u)
  24 {
  25         path->uptodate = max_t(unsigned, path->uptodate, u);
  26 }
  27
  28 static inline struct btree *btree_path_node(struct btree_path *path,
  29                                             unsigned level)
  30 {
  31         return level < BTREE_MAX_DEPTH ? path->l[level].b : NULL;
  32 }
  33
  34 static inline bool btree_node_lock_seq_matches(const struct btree_path *path,
  35                                         const struct btree *b, unsigned level)
  36 {
  37         /*
  38          * We don't compare the low bits of the lock sequence numbers because
  39          * @path might have taken a write lock on @b, and we don't want to skip
  40          * the linked path if the sequence numbers were equal before taking that
  41          * write lock. The lock sequence number is incremented by taking and
  42          * releasing write locks and is even when unlocked:
  43          */
  44         return path->l[level].lock_seq >> 1 == b->c.lock.state.seq >> 1;
  45 }
  46
  47 static inline struct btree *btree_node_parent(struct btree_path *path,
  48                                               struct btree *b)
  49 {
  50         return btree_path_node(path, b->c.level + 1);
  51 }
  52
  53 static inline int btree_iter_err(const struct btree_iter *iter)
  54 {
  55         return iter->flags & BTREE_ITER_ERROR ? -EIO : 0;
  56 }
  57
  58 /* Iterate over paths within a transaction: */
  59
  60 static inline struct btree_path *
  61 __trans_next_path(struct btree_trans *trans, unsigned idx)
  62 {
  63         u64 l;
  64
  65         if (idx == BTREE_ITER_MAX)
  66                 return NULL;
  67
  68         l = trans->paths_allocated >> idx;
  69         if (!l)
  70                 return NULL;
  71
  72         idx += __ffs64(l);
  73         EBUG_ON(idx >= BTREE_ITER_MAX);
  74         EBUG_ON(trans->paths[idx].idx != idx);
  75         return &trans->paths[idx];
  76 }
  77
  78 #define trans_for_each_path(_trans, _path)                              \
  79         for (_path = __trans_next_path((_trans), 0);                    \
  80              (_path);                                                   \
  81              _path = __trans_next_path((_trans), (_path)->idx + 1))
  82
  83 static inline struct btree_path *next_btree_path(struct btree_trans *trans, struct btree_path *path)
  84 {
  85         unsigned idx = path ? path->sorted_idx + 1 : 0;
  86
  87         EBUG_ON(idx > trans->nr_sorted);
  88
  89         return idx < trans->nr_sorted
  90                 ? trans->paths + trans->sorted[idx]
  91                 : NULL;
  92 }
  93
  94 static inline struct btree_path *prev_btree_path(struct btree_trans *trans, struct btree_path *path)
  95 {
  96         EBUG_ON(path->sorted_idx >= trans->nr_sorted);
  97         return path->sorted_idx
  98                 ? trans->paths + trans->sorted[path->sorted_idx - 1]
  99                 : NULL;
 100 }
 101
 102 #define trans_for_each_path_inorder(_trans, _path, _i)                  \
 103         for (_i = 0;                                                    \
 104              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) < (_trans)->nr_sorted;\
 105              _i++)
 106
 107 static inline bool __path_has_node(const struct btree_path *path,
 108                                    const struct btree *b)
 109 {
 110         return path->l[b->c.level].b == b &&
 111                 btree_node_lock_seq_matches(path, b, b->c.level);
 112 }
 113
 114 static inline struct btree_path *
 115 __trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
 116                             unsigned idx)
 117 {
 118         struct btree_path *path = __trans_next_path(trans, idx);
 119
 120         while (path && !__path_has_node(path, b))
 121                 path = __trans_next_path(trans, path->idx + 1);
 122
 123         return path;
 124 }
 125
 126 #define trans_for_each_path_with_node(_trans, _b, _path)                \
 127         for (_path = __trans_next_path_with_node((_trans), (_b), 0);    \
 128              (_path);                                                   \
 129              _path = __trans_next_path_with_node((_trans), (_b),        \
 130                                                  (_path)->idx + 1))
 131
 132 struct btree_path * __must_check
 133 bch2_btree_path_make_mut(struct btree_trans *, struct btree_path *, bool);
 134 int __must_check bch2_btree_path_traverse(struct btree_trans *,
 135                                           struct btree_path *, unsigned);
 136 struct btree_path *bch2_path_get(struct btree_trans *, bool, enum btree_id,
 137                                  struct bpos, unsigned, unsigned, bool);
 138 inline struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 139
 140 #ifdef CONFIG_BCACHEFS_DEBUG
 141 void bch2_trans_verify_paths(struct btree_trans *);
 142 void bch2_trans_verify_locks(struct btree_trans *);
 143 #else
 144 static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
 145 static inline void bch2_trans_verify_locks(struct btree_trans *trans) {}
 146 #endif
 147
 148 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
 149                                       struct btree *, struct bkey_packed *);
 150 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
 151                               struct btree *, struct btree_node_iter *,
 152                               struct bkey_packed *, unsigned, unsigned);
 153
 154 bool bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);
 155
 156 void bch2_path_put(struct btree_trans *, struct btree_path *, bool);
 157
 158 bool bch2_trans_relock(struct btree_trans *);
 159 void bch2_trans_unlock(struct btree_trans *);
 160
 161 __always_inline
 162 static inline int btree_trans_restart(struct btree_trans *trans)
 163 {
 164         trans->restarted = true;
 165         bch2_trans_unlock(trans);
 166         return -EINTR;
 167 }
 168
 169 bool __bch2_btree_path_upgrade(struct btree_trans *,
 170                                struct btree_path *, unsigned);
 171
 172 static inline bool bch2_btree_path_upgrade(struct btree_trans *trans,
 173                                            struct btree_path *path,
 174                                            unsigned new_locks_want)
 175 {
 176         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 177
 178         return path->locks_want < new_locks_want
 179                 ? __bch2_btree_path_upgrade(trans, path, new_locks_want)
 180                 : path->uptodate == BTREE_ITER_UPTODATE;
 181 }
 182
 183 void __bch2_btree_path_downgrade(struct btree_path *, unsigned);
 184
 185 static inline void bch2_btree_path_downgrade(struct btree_path *path)
 186 {
 187         unsigned new_locks_want = path->level + !!path->intent_ref;
 188
 189         if (path->locks_want > new_locks_want)
 190                 __bch2_btree_path_downgrade(path, new_locks_want);
 191 }
 192
 193 void bch2_trans_downgrade(struct btree_trans *);
 194
 195 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
 196 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 197
 198 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
 199 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 200
 201 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 202 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 203
 204 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 205 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 206
 207 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 208 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 209
 210 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 211 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 212 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 213
 214 bool bch2_btree_iter_advance(struct btree_iter *);
 215 bool bch2_btree_iter_rewind(struct btree_iter *);
 216
 217 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 218 {
 219         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 220                 new_pos.snapshot = iter->snapshot;
 221
 222         iter->k.type = KEY_TYPE_deleted;
 223         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 224         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 225         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 226         iter->k.size = 0;
 227         if (iter->path->ref == 1)
 228                 iter->path->should_be_locked = false;
 229 }
 230
 231 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 232 {
 233         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 234         iter->pos = bkey_start_pos(&iter->k);
 235 }
 236
 237 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 238 {
 239         struct bpos pos = iter->pos;
 240
 241         iter->snapshot = snapshot;
 242         pos.snapshot = snapshot;
 243         bch2_btree_iter_set_pos(iter, pos);
 244 }
 245
 246 /*
 247  * Unlocks before scheduling
 248  * Note: does not revalidate iterator
 249  */
 250 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 251 {
 252         if (need_resched() || race_fault()) {
 253                 bch2_trans_unlock(trans);
 254                 schedule();
 255                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 256         } else {
 257                 return 0;
 258         }
 259 }
 260
 261 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 262 void bch2_trans_iter_init(struct btree_trans *, struct btree_iter *,
 263                           unsigned, struct bpos, unsigned);
 264 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 265                                enum btree_id, struct bpos,
 266                                unsigned, unsigned, unsigned);
 267 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 268
 269 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 270 {
 271         iter->path->preserve = false;
 272 }
 273
 274 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 275 void bch2_trans_begin(struct btree_trans *);
 276
 277 static inline struct btree *
 278 __btree_iter_peek_node_and_restart(struct btree_trans *trans, struct btree_iter *iter)
 279 {
 280         struct btree *b;
 281
 282         while (b = bch2_btree_iter_peek_node(iter),
 283                PTR_ERR_OR_ZERO(b) == -EINTR)
 284                 bch2_trans_begin(trans);
 285
 286         return b;
 287 }
 288
 289 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 290                               _locks_want, _depth, _flags, _b, _ret)    \
 291         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 292                                 _start, _locks_want, _depth, _flags);   \
 293              (_b) = __btree_iter_peek_node_and_restart((_trans), &(_iter)),\
 294              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
 295              (_b) = bch2_btree_iter_next_node(&(_iter)))
 296
 297 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 298                             _flags, _b, _ret)                           \
 299         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 300                               0, 0, _flags, _b, _ret)
 301
 302 static inline int bkey_err(struct bkey_s_c k)
 303 {
 304         return PTR_ERR_OR_ZERO(k.k);
 305 }
 306
 307 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 308                                                      unsigned flags)
 309 {
 310         return flags & BTREE_ITER_SLOTS
 311                 ? bch2_btree_iter_peek_slot(iter)
 312                 : bch2_btree_iter_peek(iter);
 313 }
 314
 315 static inline struct bkey_s_c
 316 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 317                                    struct btree_iter *iter, unsigned flags)
 318 {
 319         struct bkey_s_c k;
 320
 321         while (k = __bch2_btree_iter_peek(iter, flags),
 322                bkey_err(k) == -EINTR)
 323                 bch2_trans_begin(trans);
 324
 325         return k;
 326 }
 327
 328 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 329                            _start, _flags, _k, _ret)                    \
 330         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 331                                   (_start), (_flags));                  \
 332              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 333              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 334              bch2_btree_iter_advance(&(_iter)))
 335
 336 #define for_each_btree_key_norestart(_trans, _iter, _btree_id,          \
 337                            _start, _flags, _k, _ret)                    \
 338         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 339                                   (_start), (_flags));                  \
 340              (_k) = __bch2_btree_iter_peek(&(_iter), _flags),           \
 341              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 342              bch2_btree_iter_advance(&(_iter)))
 343
 344 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _ret)    \
 345         for (;                                                          \
 346              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 347              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 348              bch2_btree_iter_advance(&(_iter)))
 349
 350 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
 351         for (;                                                          \
 352              (_k) = __bch2_btree_iter_peek(&(_iter), _flags),           \
 353              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 354              bch2_btree_iter_advance(&(_iter)))
 355
 356 /* new multiple iterator interface: */
 357
 358 void bch2_dump_trans_paths_updates(struct btree_trans *);
 359 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 360 void bch2_trans_exit(struct btree_trans *);
 361
 362 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 363
 364 void bch2_fs_btree_iter_exit(struct bch_fs *);
 365 int bch2_fs_btree_iter_init(struct bch_fs *);
 366
 367 #endif /* _BCACHEFS_BTREE_ITER_H */