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 /* Iterate over paths within a transaction: */
  54
  55 static inline struct btree_path *
  56 __trans_next_path(struct btree_trans *trans, unsigned idx)
  57 {
  58         u64 l;
  59
  60         if (idx == BTREE_ITER_MAX)
  61                 return NULL;
  62
  63         l = trans->paths_allocated >> idx;
  64         if (!l)
  65                 return NULL;
  66
  67         idx += __ffs64(l);
  68         EBUG_ON(idx >= BTREE_ITER_MAX);
  69         EBUG_ON(trans->paths[idx].idx != idx);
  70         return &trans->paths[idx];
  71 }
  72
  73 void bch2_btree_path_check_sort(struct btree_trans *, struct btree_path *, int);
  74
  75 #define trans_for_each_path(_trans, _path)                              \
  76         for (_path = __trans_next_path((_trans), 0);                    \
  77              (_path);                                                   \
  78              _path = __trans_next_path((_trans), (_path)->idx + 1))
  79
  80 static inline struct btree_path *next_btree_path(struct btree_trans *trans, struct btree_path *path)
  81 {
  82         unsigned idx = path ? path->sorted_idx + 1 : 0;
  83
  84         EBUG_ON(idx > trans->nr_sorted);
  85
  86         return idx < trans->nr_sorted
  87                 ? trans->paths + trans->sorted[idx]
  88                 : NULL;
  89 }
  90
  91 static inline struct btree_path *prev_btree_path(struct btree_trans *trans, struct btree_path *path)
  92 {
  93         EBUG_ON(path->sorted_idx >= trans->nr_sorted);
  94         return path->sorted_idx
  95                 ? trans->paths + trans->sorted[path->sorted_idx - 1]
  96                 : NULL;
  97 }
  98
  99 #define trans_for_each_path_inorder(_trans, _path, _i)                  \
 100         for (_i = 0;                                                    \
 101              ((_path) = (_trans)->paths + trans->sorted[_i]), (_i) < (_trans)->nr_sorted;\
 102              _i++)
 103
 104 static inline bool __path_has_node(const struct btree_path *path,
 105                                    const struct btree *b)
 106 {
 107         return path->l[b->c.level].b == b &&
 108                 btree_node_lock_seq_matches(path, b, b->c.level);
 109 }
 110
 111 static inline struct btree_path *
 112 __trans_next_path_with_node(struct btree_trans *trans, struct btree *b,
 113                             unsigned idx)
 114 {
 115         struct btree_path *path = __trans_next_path(trans, idx);
 116
 117         while (path && !__path_has_node(path, b))
 118                 path = __trans_next_path(trans, path->idx + 1);
 119
 120         return path;
 121 }
 122
 123 #define trans_for_each_path_with_node(_trans, _b, _path)                \
 124         for (_path = __trans_next_path_with_node((_trans), (_b), 0);    \
 125              (_path);                                                   \
 126              _path = __trans_next_path_with_node((_trans), (_b),        \
 127                                                  (_path)->idx + 1))
 128
 129 struct btree_path * __must_check
 130 bch2_btree_path_make_mut(struct btree_trans *, struct btree_path *,
 131                          bool, unsigned long);
 132 struct btree_path * __must_check
 133 bch2_btree_path_set_pos(struct btree_trans *, struct btree_path *,
 134                         struct bpos, bool, unsigned long);
 135 int __must_check bch2_btree_path_traverse(struct btree_trans *,
 136                                           struct btree_path *, unsigned);
 137 struct btree_path *bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
 138                                  unsigned, unsigned, unsigned, unsigned long);
 139 inline struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 140
 141 #ifdef CONFIG_BCACHEFS_DEBUG
 142 void bch2_trans_verify_paths(struct btree_trans *);
 143 void bch2_trans_verify_locks(struct btree_trans *);
 144 void bch2_assert_pos_locked(struct btree_trans *, enum btree_id,
 145                             struct bpos, bool);
 146 #else
 147 static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
 148 static inline void bch2_trans_verify_locks(struct btree_trans *trans) {}
 149 static inline void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
 150                                           struct bpos pos, bool key_cache) {}
 151 #endif
 152
 153 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
 154                                       struct btree *, struct bkey_packed *);
 155 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
 156                               struct btree *, struct btree_node_iter *,
 157                               struct bkey_packed *, unsigned, unsigned);
 158
 159 bool bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);
 160
 161 void bch2_path_put(struct btree_trans *, struct btree_path *, bool);
 162
 163 bool bch2_trans_relock(struct btree_trans *);
 164 void bch2_trans_unlock(struct btree_trans *);
 165
 166 __always_inline
 167 static inline int btree_trans_restart(struct btree_trans *trans)
 168 {
 169         trans->restarted = true;
 170         bch2_trans_unlock(trans);
 171         return -EINTR;
 172 }
 173
 174 bool bch2_btree_node_upgrade(struct btree_trans *,
 175                              struct btree_path *, unsigned);
 176
 177 bool __bch2_btree_path_upgrade(struct btree_trans *,
 178                                struct btree_path *, unsigned);
 179
 180 static inline bool bch2_btree_path_upgrade(struct btree_trans *trans,
 181                                            struct btree_path *path,
 182                                            unsigned new_locks_want)
 183 {
 184         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 185
 186         return path->locks_want < new_locks_want
 187                 ? __bch2_btree_path_upgrade(trans, path, new_locks_want)
 188                 : path->uptodate == BTREE_ITER_UPTODATE;
 189 }
 190
 191 void __bch2_btree_path_downgrade(struct btree_path *, unsigned);
 192
 193 static inline void bch2_btree_path_downgrade(struct btree_path *path)
 194 {
 195         unsigned new_locks_want = path->level + !!path->intent_ref;
 196
 197         if (path->locks_want > new_locks_want)
 198                 __bch2_btree_path_downgrade(path, new_locks_want);
 199 }
 200
 201 void bch2_trans_downgrade(struct btree_trans *);
 202
 203 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
 204 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
 205
 206 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
 207 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
 208
 209 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
 210 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
 211
 212 struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *);
 213 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
 214
 215 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
 216 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
 217
 218 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
 219 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
 220 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
 221
 222 bool bch2_btree_iter_advance(struct btree_iter *);
 223 bool bch2_btree_iter_rewind(struct btree_iter *);
 224
 225 static inline void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 226 {
 227         iter->k.type = KEY_TYPE_deleted;
 228         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 229         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 230         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 231         iter->k.size = 0;
 232 }
 233
 234 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 235 {
 236         if (unlikely(iter->update_path))
 237                 bch2_path_put(iter->trans, iter->update_path,
 238                               iter->flags & BTREE_ITER_INTENT);
 239         iter->update_path = NULL;
 240
 241         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 242                 new_pos.snapshot = iter->snapshot;
 243
 244         __bch2_btree_iter_set_pos(iter, new_pos);
 245 }
 246
 247 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 248 {
 249         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 250         iter->pos = bkey_start_pos(&iter->k);
 251 }
 252
 253 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 254 {
 255         struct bpos pos = iter->pos;
 256
 257         iter->snapshot = snapshot;
 258         pos.snapshot = snapshot;
 259         bch2_btree_iter_set_pos(iter, pos);
 260 }
 261
 262 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 263 void bch2_trans_iter_init(struct btree_trans *, struct btree_iter *,
 264                           unsigned, struct bpos, unsigned);
 265 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 266                                enum btree_id, struct bpos,
 267                                unsigned, unsigned, unsigned);
 268 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 269
 270 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 271 {
 272         iter->path->preserve = false;
 273 }
 274
 275 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 276 void bch2_trans_begin(struct btree_trans *);
 277
 278 static inline struct btree *
 279 __btree_iter_peek_node_and_restart(struct btree_trans *trans, struct btree_iter *iter)
 280 {
 281         struct btree *b;
 282
 283         while (b = bch2_btree_iter_peek_node(iter),
 284                PTR_ERR_OR_ZERO(b) == -EINTR)
 285                 bch2_trans_begin(trans);
 286
 287         return b;
 288 }
 289
 290 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 291                               _locks_want, _depth, _flags, _b, _ret)    \
 292         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 293                                 _start, _locks_want, _depth, _flags);   \
 294              (_b) = __btree_iter_peek_node_and_restart((_trans), &(_iter)),\
 295              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
 296              (_b) = bch2_btree_iter_next_node(&(_iter)))
 297
 298 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 299                             _flags, _b, _ret)                           \
 300         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 301                               0, 0, _flags, _b, _ret)
 302
 303 static inline int bkey_err(struct bkey_s_c k)
 304 {
 305         return PTR_ERR_OR_ZERO(k.k);
 306 }
 307
 308 static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
 309                                                      unsigned flags)
 310 {
 311         return flags & BTREE_ITER_SLOTS
 312                 ? bch2_btree_iter_peek_slot(iter)
 313                 : bch2_btree_iter_peek(iter);
 314 }
 315
 316 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
 317 {
 318         return hweight64(trans->paths_allocated) > BTREE_ITER_MAX / 2
 319                 ? -EINTR : 0;
 320 }
 321
 322 static inline struct bkey_s_c
 323 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 324                                    struct btree_iter *iter, unsigned flags)
 325 {
 326         struct bkey_s_c k;
 327
 328         while (btree_trans_too_many_iters(trans) ||
 329                (k = bch2_btree_iter_peek_type(iter, flags),
 330                 bkey_err(k) == -EINTR))
 331                 bch2_trans_begin(trans);
 332
 333         return k;
 334 }
 335
 336 #define for_each_btree_key(_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_and_restart((_trans), &(_iter), _flags),\
 341              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 342              bch2_btree_iter_advance(&(_iter)))
 343
 344 #define for_each_btree_key_norestart(_trans, _iter, _btree_id,          \
 345                            _start, _flags, _k, _ret)                    \
 346         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 347                                   (_start), (_flags));                  \
 348              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 349              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 350              bch2_btree_iter_advance(&(_iter)))
 351
 352 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _ret)    \
 353         for (;                                                          \
 354              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 355              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 356              bch2_btree_iter_advance(&(_iter)))
 357
 358 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
 359         for (;                                                          \
 360              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
 361              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 362              bch2_btree_iter_advance(&(_iter)))
 363
 364 /* new multiple iterator interface: */
 365
 366 void bch2_dump_trans_paths_updates(struct btree_trans *);
 367 void __bch2_trans_init(struct btree_trans *, struct bch_fs *,
 368                        unsigned, size_t, const char *);
 369 void bch2_trans_exit(struct btree_trans *);
 370
 371 #define bch2_trans_init(...)    __bch2_trans_init(__VA_ARGS__, __func__)
 372
 373 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 374
 375 void bch2_fs_btree_iter_exit(struct bch_fs *);
 376 int bch2_fs_btree_iter_init(struct bch_fs *);
 377
 378 #endif /* _BCACHEFS_BTREE_ITER_H */