fs/bcachefs/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 void __bch2_btree_trans_sort_paths(struct btree_trans *);
  61
  62 static inline void btree_trans_sort_paths(struct btree_trans *trans)
  63 {
  64         if (!IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
  65             trans->paths_sorted)
  66                 return;
  67         __bch2_btree_trans_sort_paths(trans);
  68 }
  69
  70 static inline struct btree_path *
  71 __trans_next_path(struct btree_trans *trans, unsigned idx)
  72 {
  73         u64 l;
  74
  75         if (idx == BTREE_ITER_MAX)
  76                 return NULL;
  77
  78         l = trans->paths_allocated >> idx;
  79         if (!l)
  80                 return NULL;
  81
  82         idx += __ffs64(l);
  83         EBUG_ON(idx >= BTREE_ITER_MAX);
  84         EBUG_ON(trans->paths[idx].idx != idx);
  85         return &trans->paths[idx];
  86 }
  87
  88 #define trans_for_each_path(_trans, _path)                              \
  89         for (_path = __trans_next_path((_trans), 0);                    \
  90              (_path);                                                   \
  91              _path = __trans_next_path((_trans), (_path)->idx + 1))
  92
  93 static inline struct btree_path *next_btree_path(struct btree_trans *trans, struct btree_path *path)
  94 {
  95         unsigned idx = path ? path->sorted_idx + 1 : 0;
  96
  97         EBUG_ON(idx > trans->nr_sorted);
  98
  99         return idx < trans->nr_sorted
 100                 ? trans->paths + trans->sorted[idx]
 101                 : NULL;
 102 }
 103
 104 static inline struct btree_path *prev_btree_path(struct btree_trans *trans, struct btree_path *path)
 105 {
 106         unsigned idx = path ? path->sorted_idx : trans->nr_sorted;
 107
 108         return idx
 109                 ? trans->paths + trans->sorted[idx - 1]
 110                 : NULL;
 111 }
 112
 113 #define trans_for_each_path_inorder(_trans, _path, _i)                  \
 114         for (_i = 0;                                                    \
 115              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) < (_trans)->nr_sorted;\
 116              _i++)
 117
 118 #define trans_for_each_path_inorder_reverse(_trans, _path, _i)          \
 119         for (_i = trans->nr_sorted - 1;                                 \
 120              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) >= 0;\
 121              --_i)
 122
 123 static inline bool __path_has_node(const struct btree_path *path,
 124                                    const struct btree *b)
 125 {
 126         return path->l[b->c.level].b == b &&
 127                 btree_node_lock_seq_matches(path, b, b->c.level);
 128 }
 129
 130 static inline struct btree_path *
 131 __trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
 132                             unsigned idx)
 133 {
 134         struct btree_path *path = __trans_next_path(trans, idx);
 135
 136         while (path && !__path_has_node(path, b))
 137                 path = __trans_next_path(trans, path->idx + 1);
 138
 139         return path;
 140 }
 141
 142 #define trans_for_each_path_with_node(_trans, _b, _path)                \
 143         for (_path = __trans_next_path_with_node((_trans), (_b), 0);    \
 144              (_path);                                                   \
 145              _path = __trans_next_path_with_node((_trans), (_b),        \
 146                                                  (_path)->idx + 1))
 147
 148 struct btree_path *__bch2_btree_path_make_mut(struct btree_trans *,
 149                                               struct btree_path *, bool);
 150
 151 static inline struct btree_path * __must_check
 152 bch2_btree_path_make_mut(struct btree_trans *trans,
 153                          struct btree_path *path, bool intent)
 154 {
 155         if (path->ref > 1 || path->preserve)
 156                 path = __bch2_btree_path_make_mut(trans, path, intent);
 157         return path;
 158 }
 159
 160 int __must_check bch2_btree_path_traverse(struct btree_trans *,
 161                                           struct btree_path *, unsigned);
 162 struct btree_path *bch2_path_get(struct btree_trans *, bool, enum btree_id,
 163                                  struct bpos, unsigned, unsigned, bool);
 164 inline struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 165
 166 #ifdef CONFIG_BCACHEFS_DEBUG
 167 void bch2_trans_verify_paths(struct btree_trans *);
 168 void bch2_trans_verify_locks(struct btree_trans *);
 169 #else
 170 static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
 171 static inline void bch2_trans_verify_locks(struct btree_trans *trans) {}
 172 #endif
 173
 174 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
 175                                       struct btree *, struct bkey_packed *);
 176 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
 177                               struct btree *, struct btree_node_iter *,
 178                               struct bkey_packed *, unsigned, unsigned);
 179
 180 bool bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);
 181
 182 void bch2_path_put(struct btree_trans *, struct btree_path *, bool);
 183
 184 bool bch2_trans_relock(struct btree_trans *);
 185 void bch2_trans_unlock(struct btree_trans *);
 186
 187 __always_inline
 188 static inline int btree_trans_restart(struct btree_trans *trans)
 189 {
 190         trans->restarted = true;
 191         bch2_trans_unlock(trans);
 192         return -EINTR;
 193 }
 194
 195 bool __bch2_btree_path_upgrade(struct btree_trans *,
 196                                struct btree_path *, unsigned);
 197
 198 static inline bool bch2_btree_path_upgrade(struct btree_trans *trans,
 199                                            struct btree_path *path,
 200                                            unsigned new_locks_want)
 201 {
 202         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 203
 204         return path->locks_want < new_locks_want
 205                 ? __bch2_btree_path_upgrade(trans, path, new_locks_want)
 206                 : path->uptodate == BTREE_ITER_UPTODATE;
 207 }
 208
 209 void __bch2_btree_path_downgrade(struct btree_path *, unsigned);
 210
 211 static inline void bch2_btree_path_downgrade(struct btree_path *path)
 212 {
 213         unsigned new_locks_want = path->level + !!path->intent_ref;
 214
 215         if (path->locks_want > new_locks_want)
 216                 __bch2_btree_path_downgrade(path, new_locks_want);
 217 }
 218
 219 void bch2_trans_downgrade(struct btree_trans *);
 220
 221 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
 222 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 223
 224 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
 225 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 226
 227 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 228 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 229
 230 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 231 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 232
 233 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 234 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 235
 236 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 237 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 238 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 239
 240 bool bch2_btree_iter_advance(struct btree_iter *);
 241 bool bch2_btree_iter_rewind(struct btree_iter *);
 242
 243 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 244 {
 245         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 246                 new_pos.snapshot = iter->snapshot;
 247
 248         iter->k.type = KEY_TYPE_deleted;
 249         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 250         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 251         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 252         iter->k.size = 0;
 253         if (iter->path->ref == 1)
 254                 iter->path->should_be_locked = false;
 255 }
 256
 257 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 258 {
 259         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 260         iter->pos = bkey_start_pos(&iter->k);
 261 }
 262
 263 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 264 {
 265         struct bpos pos = iter->pos;
 266
 267         iter->snapshot = snapshot;
 268         pos.snapshot = snapshot;
 269         bch2_btree_iter_set_pos(iter, pos);
 270 }
 271
 272 /*
 273  * Unlocks before scheduling
 274  * Note: does not revalidate iterator
 275  */
 276 static inline int bch2_trans_cond_resched(struct btree_trans *trans)
 277 {
 278         if (need_resched() || race_fault()) {
 279                 bch2_trans_unlock(trans);
 280                 schedule();
 281                 return bch2_trans_relock(trans) ? 0 : -EINTR;
 282         } else {
 283                 return 0;
 284         }
 285 }
 286
 287 #define __for_each_btree_node(_trans, _iter, _btree_id, _start, \
 288                               _locks_want, _depth, _flags, _b)          \
 289         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 290                                 _start, _locks_want, _depth, _flags),   \
 291              _b = bch2_btree_iter_peek_node(&(_iter));                  \
 292              (_b);                                                      \
 293              (_b) = bch2_btree_iter_next_node(&(_iter)))
 294
 295 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 296                             _flags, _b)                                 \
 297         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 298                               0, 0, _flags, _b)
 299
 300 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 301                                                      unsigned flags)
 302 {
 303         return flags & BTREE_ITER_SLOTS
 304                 ? bch2_btree_iter_peek_slot(iter)
 305                 : bch2_btree_iter_peek(iter);
 306 }
 307
 308 static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 309                                                      unsigned flags)
 310 {
 311         return flags & BTREE_ITER_SLOTS
 312                 ? bch2_btree_iter_next_slot(iter)
 313                 : bch2_btree_iter_next(iter);
 314 }
 315
 316 static inline int bkey_err(struct bkey_s_c k)
 317 {
 318         return PTR_ERR_OR_ZERO(k.k);
 319 }
 320
 321 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 322                            _start, _flags, _k, _ret)                    \
 323         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 324                                   (_start), (_flags)),                  \
 325              (_k) = __bch2_btree_iter_peek(&(_iter), _flags);           \
 326              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 327              (_k) = __bch2_btree_iter_next(&(_iter), _flags))
 328
 329 #define for_each_btree_key_continue(_iter, _flags, _k, _ret)            \
 330         for ((_k) = __bch2_btree_iter_peek(&(_iter), _flags);           \
 331              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 332              (_k) = __bch2_btree_iter_next(&(_iter), _flags))
 333
 334 /* new multiple iterator interface: */
 335
 336 void bch2_dump_trans_paths_updates(struct btree_trans *);
 337
 338 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 339 void bch2_trans_iter_init(struct btree_trans *, struct btree_iter *,
 340                           unsigned, struct bpos, unsigned);
 341 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 342                                enum btree_id, struct bpos,
 343                                unsigned, unsigned, unsigned);
 344 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 345
 346 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 347 {
 348         iter->path->preserve = false;
 349 }
 350
 351 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 352 void bch2_trans_begin(struct btree_trans *);
 353 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 354 int bch2_trans_exit(struct btree_trans *);
 355
 356 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 357
 358 void bch2_fs_btree_iter_exit(struct bch_fs *);
 359 int bch2_fs_btree_iter_init(struct bch_fs *);
 360
 361 #endif /* _BCACHEFS_BTREE_ITER_H */