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[bcachefs-tools-debian] / 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 struct bkey_i *bch2_btree_journal_peek_slot(struct btree_trans *,
142                                         struct btree_iter *, struct bpos);
143
144 #ifdef CONFIG_BCACHEFS_DEBUG
145 void bch2_trans_verify_paths(struct btree_trans *);
146 void bch2_trans_verify_locks(struct btree_trans *);
147 void bch2_assert_pos_locked(struct btree_trans *, enum btree_id,
148                             struct bpos, bool);
149 #else
150 static inline void bch2_trans_verify_paths(struct btree_trans *trans) {}
151 static inline void bch2_trans_verify_locks(struct btree_trans *trans) {}
152 static inline void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
153                                           struct bpos pos, bool key_cache) {}
154 #endif
155
156 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
157                                       struct btree *, struct bkey_packed *);
158 void bch2_btree_node_iter_fix(struct btree_trans *trans, struct btree_path *,
159                               struct btree *, struct btree_node_iter *,
160                               struct bkey_packed *, unsigned, unsigned);
161
162 bool bch2_btree_path_relock_intent(struct btree_trans *, struct btree_path *);
163
164 void bch2_path_put(struct btree_trans *, struct btree_path *, bool);
165
166 bool bch2_trans_relock(struct btree_trans *);
167 void bch2_trans_unlock(struct btree_trans *);
168
169 __always_inline
170 static inline int btree_trans_restart(struct btree_trans *trans)
171 {
172         trans->restarted = true;
173         bch2_trans_unlock(trans);
174         return -EINTR;
175 }
176
177 bool bch2_btree_node_upgrade(struct btree_trans *,
178                              struct btree_path *, unsigned);
179
180 bool __bch2_btree_path_upgrade(struct btree_trans *,
181                                struct btree_path *, unsigned);
182
183 static inline bool bch2_btree_path_upgrade(struct btree_trans *trans,
184                                            struct btree_path *path,
185                                            unsigned new_locks_want)
186 {
187         new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
188
189         return path->locks_want < new_locks_want
190                 ? __bch2_btree_path_upgrade(trans, path, new_locks_want)
191                 : path->uptodate == BTREE_ITER_UPTODATE;
192 }
193
194 void __bch2_btree_path_downgrade(struct btree_path *, unsigned);
195
196 static inline void bch2_btree_path_downgrade(struct btree_path *path)
197 {
198         unsigned new_locks_want = path->level + !!path->intent_ref;
199
200         if (path->locks_want > new_locks_want)
201                 __bch2_btree_path_downgrade(path, new_locks_want);
202 }
203
204 void bch2_trans_downgrade(struct btree_trans *);
205
206 void bch2_trans_node_add(struct btree_trans *trans, struct btree *);
207 void bch2_trans_node_reinit_iter(struct btree_trans *, struct btree *);
208
209 int __must_check __bch2_btree_iter_traverse(struct btree_iter *iter);
210 int __must_check bch2_btree_iter_traverse(struct btree_iter *);
211
212 struct btree *bch2_btree_iter_peek_node(struct btree_iter *);
213 struct btree *bch2_btree_iter_next_node(struct btree_iter *);
214
215 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *, struct bpos);
216 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *);
217
218 struct bkey_s_c bch2_btree_iter_peek_all_levels(struct btree_iter *);
219
220 static inline struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
221 {
222         return bch2_btree_iter_peek_upto(iter, SPOS_MAX);
223 }
224
225 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *);
226 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *);
227
228 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *);
229 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *);
230 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *);
231
232 bool bch2_btree_iter_advance(struct btree_iter *);
233 bool bch2_btree_iter_rewind(struct btree_iter *);
234
235 static inline void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
236 {
237         iter->k.type = KEY_TYPE_deleted;
238         iter->k.p.inode         = iter->pos.inode       = new_pos.inode;
239         iter->k.p.offset        = iter->pos.offset      = new_pos.offset;
240         iter->k.p.snapshot      = iter->pos.snapshot    = new_pos.snapshot;
241         iter->k.size = 0;
242 }
243
244 static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
245 {
246         if (unlikely(iter->update_path))
247                 bch2_path_put(iter->trans, iter->update_path,
248                               iter->flags & BTREE_ITER_INTENT);
249         iter->update_path = NULL;
250
251         if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
252                 new_pos.snapshot = iter->snapshot;
253
254         __bch2_btree_iter_set_pos(iter, new_pos);
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 void bch2_trans_iter_exit(struct btree_trans *, struct btree_iter *);
273 void bch2_trans_iter_init(struct btree_trans *, struct btree_iter *,
274                           unsigned, struct bpos, unsigned);
275 void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
276                                enum btree_id, struct bpos,
277                                unsigned, unsigned, unsigned);
278 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
279
280 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
281 {
282         iter->path->preserve = false;
283 }
284
285 void *bch2_trans_kmalloc(struct btree_trans *, size_t);
286 void bch2_trans_begin(struct btree_trans *);
287
288 static inline struct btree *
289 __btree_iter_peek_node_and_restart(struct btree_trans *trans, struct btree_iter *iter)
290 {
291         struct btree *b;
292
293         while (b = bch2_btree_iter_peek_node(iter),
294                PTR_ERR_OR_ZERO(b) == -EINTR)
295                 bch2_trans_begin(trans);
296
297         return b;
298 }
299
300 #define __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
301                               _locks_want, _depth, _flags, _b, _ret)    \
302         for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id), \
303                                 _start, _locks_want, _depth, _flags);   \
304              (_b) = __btree_iter_peek_node_and_restart((_trans), &(_iter)),\
305              !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);                   \
306              (_b) = bch2_btree_iter_next_node(&(_iter)))
307
308 #define for_each_btree_node(_trans, _iter, _btree_id, _start,           \
309                             _flags, _b, _ret)                           \
310         __for_each_btree_node(_trans, _iter, _btree_id, _start,         \
311                               0, 0, _flags, _b, _ret)
312
313 static inline int bkey_err(struct bkey_s_c k)
314 {
315         return PTR_ERR_OR_ZERO(k.k);
316 }
317
318 static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
319                                                         unsigned flags)
320 {
321         return  flags & BTREE_ITER_ALL_LEVELS ? bch2_btree_iter_peek_all_levels(iter) :
322                 flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
323                                                 bch2_btree_iter_peek(iter);
324 }
325
326 static inline struct bkey_s_c bch2_btree_iter_peek_upto_type(struct btree_iter *iter,
327                                                              struct bpos end,
328                                                              unsigned flags)
329 {
330         if (!(flags & BTREE_ITER_SLOTS))
331                 return bch2_btree_iter_peek_upto(iter, end);
332
333         if (bkey_cmp(iter->pos, end) > 0)
334                 return bkey_s_c_null;
335
336         return bch2_btree_iter_peek_slot(iter);
337 }
338
339 static inline int btree_trans_too_many_iters(struct btree_trans *trans)
340 {
341         return hweight64(trans->paths_allocated) > BTREE_ITER_MAX / 2
342                 ? -EINTR : 0;
343 }
344
345 static inline struct bkey_s_c
346 __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
347                                    struct btree_iter *iter, unsigned flags)
348 {
349         struct bkey_s_c k;
350
351         while (btree_trans_too_many_iters(trans) ||
352                (k = bch2_btree_iter_peek_type(iter, flags),
353                 bkey_err(k) == -EINTR))
354                 bch2_trans_begin(trans);
355
356         return k;
357 }
358
359 #define for_each_btree_key(_trans, _iter, _btree_id,                    \
360                            _start, _flags, _k, _ret)                    \
361         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
362                                   (_start), (_flags));                  \
363              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
364              !((_ret) = bkey_err(_k)) && (_k).k;                        \
365              bch2_btree_iter_advance(&(_iter)))
366
367 #define for_each_btree_key_norestart(_trans, _iter, _btree_id,          \
368                            _start, _flags, _k, _ret)                    \
369         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
370                                   (_start), (_flags));                  \
371              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
372              !((_ret) = bkey_err(_k)) && (_k).k;                        \
373              bch2_btree_iter_advance(&(_iter)))
374
375 #define for_each_btree_key_upto_norestart(_trans, _iter, _btree_id,     \
376                            _start, _end, _flags, _k, _ret)              \
377         for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),      \
378                                   (_start), (_flags));                  \
379              (_k) = bch2_btree_iter_peek_upto_type(&(_iter), _end, _flags),\
380              !((_ret) = bkey_err(_k)) && (_k).k;                        \
381              bch2_btree_iter_advance(&(_iter)))
382
383 #define for_each_btree_key_continue(_trans, _iter, _flags, _k, _ret)    \
384         for (;                                                          \
385              (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
386              !((_ret) = bkey_err(_k)) && (_k).k;                        \
387              bch2_btree_iter_advance(&(_iter)))
388
389 #define for_each_btree_key_continue_norestart(_iter, _flags, _k, _ret)  \
390         for (;                                                          \
391              (_k) = bch2_btree_iter_peek_type(&(_iter), _flags),        \
392              !((_ret) = bkey_err(_k)) && (_k).k;                        \
393              bch2_btree_iter_advance(&(_iter)))
394
395 /* new multiple iterator interface: */
396
397 void bch2_trans_updates_to_text(struct printbuf *, struct btree_trans *);
398 void bch2_dump_trans_updates(struct btree_trans *);
399 void bch2_dump_trans_paths_updates(struct btree_trans *);
400 void __bch2_trans_init(struct btree_trans *, struct bch_fs *,
401                        unsigned, size_t, const char *);
402 void bch2_trans_exit(struct btree_trans *);
403
404 #define bch2_trans_init(...)    __bch2_trans_init(__VA_ARGS__, __func__)
405
406 void bch2_btree_trans_to_text(struct printbuf *, struct bch_fs *);
407
408 void bch2_fs_btree_iter_exit(struct bch_fs *);
409 int bch2_fs_btree_iter_init(struct bch_fs *);
410
411 #endif /* _BCACHEFS_BTREE_ITER_H */