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 *,
 134                          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         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
 228                 new_pos.snapshot = iter->snapshot;
 229
 230         iter->k.type = KEY_TYPE_deleted;
 231         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
 232         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
 233         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
 234         iter->k.size = 0;
 235 }
 236
 237 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 238 {
 239         BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
 240         iter->pos = bkey_start_pos(&iter->k);
 241 }
 242
 243 static inline void bch2_btree_iter_set_snapshot(struct btree_iter *iter, u32 snapshot)
 244 {
 245         struct bpos pos = iter->pos;
 246
 247         iter->snapshot = snapshot;
 248         pos.snapshot = snapshot;
 249         bch2_btree_iter_set_pos(iter, pos);
 250 }
 251
 252 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
 253 void bch2_trans_iter_init(struct btree_trans *, struct btree_iter *,
 254                           unsigned, struct bpos, unsigned);
 255 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 256                                enum btree_id, struct bpos,
 257                                unsigned, unsigned, unsigned);
 258 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 259
 260 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 261 {
 262         iter->path->preserve = false;
 263 }
 264
 265 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
 266 void bch2_trans_begin(struct btree_trans *);
 267
 268 static inline struct btree *
 269 __btree_iter_peek_node_and_restart(struct btree_trans *trans, struct btree_iter *iter)
 270 {
 271         struct btree *b;
 272
 273         while (b = bch2_btree_iter_peek_node(iter),
 274                PTR_ERR_OR_ZERO(b) == -EINTR)
 275                 bch2_trans_begin(trans);
 276
 277         return b;
 278 }
 279
 280 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 281                               _locks_want, _depth, _flags, _b, _ret)    \
 282         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
 283                                 _start, _locks_want, _depth, _flags);   \
 284              (_b) = __btree_iter_peek_node_and_restart((_trans), &(_iter)),\
 285              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
 286              (_b) = bch2_btree_iter_next_node(&(_iter)))
 287
 288 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
 289                             _flags, _b, _ret)                           \
 290         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
 291                               0, 0, _flags, _b, _ret)
 292
 293 static inline int bkey_err(struct bkey_s_c k)
 294 {
 295         return PTR_ERR_OR_ZERO(k.k);
 296 }
 297
 298 static inline struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter,
 299                                                      unsigned flags)
 300 {
 301         return flags & BTREE_ITER_SLOTS
 302                 ? bch2_btree_iter_peek_slot(iter)
 303                 : bch2_btree_iter_peek(iter);
 304 }
 305
 306 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
 307 {
 308         return hweight64(trans->paths_allocated) > BTREE_ITER_MAX / 2
 309                 ? -EINTR : 0;
 310 }
 311
 312 static inline struct bkey_s_c
 313 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 314                                    struct btree_iter *iter, unsigned flags)
 315 {
 316         struct bkey_s_c k;
 317
 318         while (btree_trans_too_many_iters(trans) ||
 319                (k = __bch2_btree_iter_peek(iter, flags),
 320                 bkey_err(k) == -EINTR))
 321                 bch2_trans_begin(trans);
 322
 323         return k;
 324 }
 325
 326 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
 327                            _start, _flags, _k, _ret)                    \
 328         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
 329                                   (_start), (_flags));                  \
 330              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 331              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 332              bch2_btree_iter_advance(&(_iter)))
 333
 334 #define for_each_btree_key_norestart(_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(&(_iter), _flags),           \
 339              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 340              bch2_btree_iter_advance(&(_iter)))
 341
 342 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _ret)    \
 343         for (;                                                          \
 344              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
 345              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 346              bch2_btree_iter_advance(&(_iter)))
 347
 348 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
 349         for (;                                                          \
 350              (_k) = __bch2_btree_iter_peek(&(_iter), _flags),           \
 351              !((_ret) = bkey_err(_k)) && (_k).k;                        \
 352              bch2_btree_iter_advance(&(_iter)))
 353
 354 /* new multiple iterator interface: */
 355
 356 void bch2_dump_trans_paths_updates(struct btree_trans *);
 357 void bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned, size_t);
 358 void bch2_trans_exit(struct btree_trans *);
 359
 360 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
 361
 362 void bch2_fs_btree_iter_exit(struct bch_fs *);
 363 int bch2_fs_btree_iter_init(struct bch_fs *);
 364
 365 #endif /* _BCACHEFS_BTREE_ITER_H */