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