xref: /linux/fs/bcachefs/btree_update.c (revision 268531be211f18c55f7ff5a1641d32c0fd0571cd)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include "bcachefs.h"
4 #include "btree_update.h"
5 #include "btree_iter.h"
6 #include "btree_journal_iter.h"
7 #include "btree_locking.h"
8 #include "buckets.h"
9 #include "debug.h"
10 #include "errcode.h"
11 #include "error.h"
12 #include "extents.h"
13 #include "keylist.h"
14 #include "snapshot.h"
15 #include "trace.h"
16 
17 static inline int btree_insert_entry_cmp(const struct btree_insert_entry *l,
18 					 const struct btree_insert_entry *r)
19 {
20 	return   cmp_int(l->btree_id,	r->btree_id) ?:
21 		 cmp_int(l->cached,	r->cached) ?:
22 		 -cmp_int(l->level,	r->level) ?:
23 		 bpos_cmp(l->k->k.p,	r->k->k.p);
24 }
25 
26 static int __must_check
27 bch2_trans_update_by_path(struct btree_trans *, struct btree_path *,
28 			  struct bkey_i *, enum btree_update_flags,
29 			  unsigned long ip);
30 
31 static noinline int extent_front_merge(struct btree_trans *trans,
32 				       struct btree_iter *iter,
33 				       struct bkey_s_c k,
34 				       struct bkey_i **insert,
35 				       enum btree_update_flags flags)
36 {
37 	struct bch_fs *c = trans->c;
38 	struct bkey_i *update;
39 	int ret;
40 
41 	update = bch2_bkey_make_mut_noupdate(trans, k);
42 	ret = PTR_ERR_OR_ZERO(update);
43 	if (ret)
44 		return ret;
45 
46 	if (!bch2_bkey_merge(c, bkey_i_to_s(update), bkey_i_to_s_c(*insert)))
47 		return 0;
48 
49 	ret =   bch2_key_has_snapshot_overwrites(trans, iter->btree_id, k.k->p) ?:
50 		bch2_key_has_snapshot_overwrites(trans, iter->btree_id, (*insert)->k.p);
51 	if (ret < 0)
52 		return ret;
53 	if (ret)
54 		return 0;
55 
56 	ret = bch2_btree_delete_at(trans, iter, flags);
57 	if (ret)
58 		return ret;
59 
60 	*insert = update;
61 	return 0;
62 }
63 
64 static noinline int extent_back_merge(struct btree_trans *trans,
65 				      struct btree_iter *iter,
66 				      struct bkey_i *insert,
67 				      struct bkey_s_c k)
68 {
69 	struct bch_fs *c = trans->c;
70 	int ret;
71 
72 	ret =   bch2_key_has_snapshot_overwrites(trans, iter->btree_id, insert->k.p) ?:
73 		bch2_key_has_snapshot_overwrites(trans, iter->btree_id, k.k->p);
74 	if (ret < 0)
75 		return ret;
76 	if (ret)
77 		return 0;
78 
79 	bch2_bkey_merge(c, bkey_i_to_s(insert), k);
80 	return 0;
81 }
82 
83 /*
84  * When deleting, check if we need to emit a whiteout (because we're overwriting
85  * something in an ancestor snapshot)
86  */
87 static int need_whiteout_for_snapshot(struct btree_trans *trans,
88 				      enum btree_id btree_id, struct bpos pos)
89 {
90 	struct btree_iter iter;
91 	struct bkey_s_c k;
92 	u32 snapshot = pos.snapshot;
93 	int ret;
94 
95 	if (!bch2_snapshot_parent(trans->c, pos.snapshot))
96 		return 0;
97 
98 	pos.snapshot++;
99 
100 	for_each_btree_key_norestart(trans, iter, btree_id, pos,
101 			   BTREE_ITER_ALL_SNAPSHOTS|
102 			   BTREE_ITER_NOPRESERVE, k, ret) {
103 		if (!bkey_eq(k.k->p, pos))
104 			break;
105 
106 		if (bch2_snapshot_is_ancestor(trans->c, snapshot,
107 					      k.k->p.snapshot)) {
108 			ret = !bkey_whiteout(k.k);
109 			break;
110 		}
111 	}
112 	bch2_trans_iter_exit(trans, &iter);
113 
114 	return ret;
115 }
116 
117 int __bch2_insert_snapshot_whiteouts(struct btree_trans *trans,
118 				   enum btree_id id,
119 				   struct bpos old_pos,
120 				   struct bpos new_pos)
121 {
122 	struct bch_fs *c = trans->c;
123 	struct btree_iter old_iter, new_iter = { NULL };
124 	struct bkey_s_c old_k, new_k;
125 	snapshot_id_list s;
126 	struct bkey_i *update;
127 	int ret = 0;
128 
129 	if (!bch2_snapshot_has_children(c, old_pos.snapshot))
130 		return 0;
131 
132 	darray_init(&s);
133 
134 	bch2_trans_iter_init(trans, &old_iter, id, old_pos,
135 			     BTREE_ITER_NOT_EXTENTS|
136 			     BTREE_ITER_ALL_SNAPSHOTS);
137 	while ((old_k = bch2_btree_iter_prev(&old_iter)).k &&
138 	       !(ret = bkey_err(old_k)) &&
139 	       bkey_eq(old_pos, old_k.k->p)) {
140 		struct bpos whiteout_pos =
141 			SPOS(new_pos.inode, new_pos.offset, old_k.k->p.snapshot);;
142 
143 		if (!bch2_snapshot_is_ancestor(c, old_k.k->p.snapshot, old_pos.snapshot) ||
144 		    snapshot_list_has_ancestor(c, &s, old_k.k->p.snapshot))
145 			continue;
146 
147 		new_k = bch2_bkey_get_iter(trans, &new_iter, id, whiteout_pos,
148 					   BTREE_ITER_NOT_EXTENTS|
149 					   BTREE_ITER_INTENT);
150 		ret = bkey_err(new_k);
151 		if (ret)
152 			break;
153 
154 		if (new_k.k->type == KEY_TYPE_deleted) {
155 			update = bch2_trans_kmalloc(trans, sizeof(struct bkey_i));
156 			ret = PTR_ERR_OR_ZERO(update);
157 			if (ret)
158 				break;
159 
160 			bkey_init(&update->k);
161 			update->k.p		= whiteout_pos;
162 			update->k.type		= KEY_TYPE_whiteout;
163 
164 			ret = bch2_trans_update(trans, &new_iter, update,
165 						BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
166 		}
167 		bch2_trans_iter_exit(trans, &new_iter);
168 
169 		ret = snapshot_list_add(c, &s, old_k.k->p.snapshot);
170 		if (ret)
171 			break;
172 	}
173 	bch2_trans_iter_exit(trans, &new_iter);
174 	bch2_trans_iter_exit(trans, &old_iter);
175 	darray_exit(&s);
176 
177 	return ret;
178 }
179 
180 int bch2_trans_update_extent_overwrite(struct btree_trans *trans,
181 				       struct btree_iter *iter,
182 				       enum btree_update_flags flags,
183 				       struct bkey_s_c old,
184 				       struct bkey_s_c new)
185 {
186 	enum btree_id btree_id = iter->btree_id;
187 	struct bkey_i *update;
188 	struct bpos new_start = bkey_start_pos(new.k);
189 	bool front_split = bkey_lt(bkey_start_pos(old.k), new_start);
190 	bool back_split  = bkey_gt(old.k->p, new.k->p);
191 	int ret = 0, compressed_sectors;
192 
193 	/*
194 	 * If we're going to be splitting a compressed extent, note it
195 	 * so that __bch2_trans_commit() can increase our disk
196 	 * reservation:
197 	 */
198 	if (((front_split && back_split) ||
199 	     ((front_split || back_split) && old.k->p.snapshot != new.k->p.snapshot)) &&
200 	    (compressed_sectors = bch2_bkey_sectors_compressed(old)))
201 		trans->extra_journal_res += compressed_sectors;
202 
203 	if (front_split) {
204 		update = bch2_bkey_make_mut_noupdate(trans, old);
205 		if ((ret = PTR_ERR_OR_ZERO(update)))
206 			return ret;
207 
208 		bch2_cut_back(new_start, update);
209 
210 		ret =   bch2_insert_snapshot_whiteouts(trans, btree_id,
211 					old.k->p, update->k.p) ?:
212 			bch2_btree_insert_nonextent(trans, btree_id, update,
213 					BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|flags);
214 		if (ret)
215 			return ret;
216 	}
217 
218 	/* If we're overwriting in a different snapshot - middle split: */
219 	if (old.k->p.snapshot != new.k->p.snapshot &&
220 	    (front_split || back_split)) {
221 		update = bch2_bkey_make_mut_noupdate(trans, old);
222 		if ((ret = PTR_ERR_OR_ZERO(update)))
223 			return ret;
224 
225 		bch2_cut_front(new_start, update);
226 		bch2_cut_back(new.k->p, update);
227 
228 		ret =   bch2_insert_snapshot_whiteouts(trans, btree_id,
229 					old.k->p, update->k.p) ?:
230 			bch2_btree_insert_nonextent(trans, btree_id, update,
231 					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|flags);
232 		if (ret)
233 			return ret;
234 	}
235 
236 	if (bkey_le(old.k->p, new.k->p)) {
237 		update = bch2_trans_kmalloc(trans, sizeof(*update));
238 		if ((ret = PTR_ERR_OR_ZERO(update)))
239 			return ret;
240 
241 		bkey_init(&update->k);
242 		update->k.p = old.k->p;
243 		update->k.p.snapshot = new.k->p.snapshot;
244 
245 		if (new.k->p.snapshot != old.k->p.snapshot) {
246 			update->k.type = KEY_TYPE_whiteout;
247 		} else if (btree_type_has_snapshots(btree_id)) {
248 			ret = need_whiteout_for_snapshot(trans, btree_id, update->k.p);
249 			if (ret < 0)
250 				return ret;
251 			if (ret)
252 				update->k.type = KEY_TYPE_whiteout;
253 		}
254 
255 		ret = bch2_btree_insert_nonextent(trans, btree_id, update,
256 					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|flags);
257 		if (ret)
258 			return ret;
259 	}
260 
261 	if (back_split) {
262 		update = bch2_bkey_make_mut_noupdate(trans, old);
263 		if ((ret = PTR_ERR_OR_ZERO(update)))
264 			return ret;
265 
266 		bch2_cut_front(new.k->p, update);
267 
268 		ret = bch2_trans_update_by_path(trans, iter->path, update,
269 					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
270 					  flags, _RET_IP_);
271 		if (ret)
272 			return ret;
273 	}
274 
275 	return 0;
276 }
277 
278 static int bch2_trans_update_extent(struct btree_trans *trans,
279 				    struct btree_iter *orig_iter,
280 				    struct bkey_i *insert,
281 				    enum btree_update_flags flags)
282 {
283 	struct btree_iter iter;
284 	struct bkey_s_c k;
285 	enum btree_id btree_id = orig_iter->btree_id;
286 	int ret = 0;
287 
288 	bch2_trans_iter_init(trans, &iter, btree_id, bkey_start_pos(&insert->k),
289 			     BTREE_ITER_INTENT|
290 			     BTREE_ITER_WITH_UPDATES|
291 			     BTREE_ITER_NOT_EXTENTS);
292 	k = bch2_btree_iter_peek_upto(&iter, POS(insert->k.p.inode, U64_MAX));
293 	if ((ret = bkey_err(k)))
294 		goto err;
295 	if (!k.k)
296 		goto out;
297 
298 	if (bkey_eq(k.k->p, bkey_start_pos(&insert->k))) {
299 		if (bch2_bkey_maybe_mergable(k.k, &insert->k)) {
300 			ret = extent_front_merge(trans, &iter, k, &insert, flags);
301 			if (ret)
302 				goto err;
303 		}
304 
305 		goto next;
306 	}
307 
308 	while (bkey_gt(insert->k.p, bkey_start_pos(k.k))) {
309 		bool done = bkey_lt(insert->k.p, k.k->p);
310 
311 		ret = bch2_trans_update_extent_overwrite(trans, &iter, flags, k, bkey_i_to_s_c(insert));
312 		if (ret)
313 			goto err;
314 
315 		if (done)
316 			goto out;
317 next:
318 		bch2_btree_iter_advance(&iter);
319 		k = bch2_btree_iter_peek_upto(&iter, POS(insert->k.p.inode, U64_MAX));
320 		if ((ret = bkey_err(k)))
321 			goto err;
322 		if (!k.k)
323 			goto out;
324 	}
325 
326 	if (bch2_bkey_maybe_mergable(&insert->k, k.k)) {
327 		ret = extent_back_merge(trans, &iter, insert, k);
328 		if (ret)
329 			goto err;
330 	}
331 out:
332 	if (!bkey_deleted(&insert->k))
333 		ret = bch2_btree_insert_nonextent(trans, btree_id, insert, flags);
334 err:
335 	bch2_trans_iter_exit(trans, &iter);
336 
337 	return ret;
338 }
339 
340 static noinline int flush_new_cached_update(struct btree_trans *trans,
341 					    struct btree_path *path,
342 					    struct btree_insert_entry *i,
343 					    enum btree_update_flags flags,
344 					    unsigned long ip)
345 {
346 	struct btree_path *btree_path;
347 	struct bkey k;
348 	int ret;
349 
350 	btree_path = bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
351 				   BTREE_ITER_INTENT, _THIS_IP_);
352 	ret = bch2_btree_path_traverse(trans, btree_path, 0);
353 	if (ret)
354 		goto out;
355 
356 	/*
357 	 * The old key in the insert entry might actually refer to an existing
358 	 * key in the btree that has been deleted from cache and not yet
359 	 * flushed. Check for this and skip the flush so we don't run triggers
360 	 * against a stale key.
361 	 */
362 	bch2_btree_path_peek_slot_exact(btree_path, &k);
363 	if (!bkey_deleted(&k))
364 		goto out;
365 
366 	i->key_cache_already_flushed = true;
367 	i->flags |= BTREE_TRIGGER_NORUN;
368 
369 	btree_path_set_should_be_locked(btree_path);
370 	ret = bch2_trans_update_by_path(trans, btree_path, i->k, flags, ip);
371 out:
372 	bch2_path_put(trans, btree_path, true);
373 	return ret;
374 }
375 
376 static int __must_check
377 bch2_trans_update_by_path(struct btree_trans *trans, struct btree_path *path,
378 			  struct bkey_i *k, enum btree_update_flags flags,
379 			  unsigned long ip)
380 {
381 	struct bch_fs *c = trans->c;
382 	struct btree_insert_entry *i, n;
383 	u64 seq = 0;
384 	int cmp;
385 
386 	EBUG_ON(!path->should_be_locked);
387 	EBUG_ON(trans->nr_updates >= BTREE_ITER_MAX);
388 	EBUG_ON(!bpos_eq(k->k.p, path->pos));
389 
390 	/*
391 	 * The transaction journal res hasn't been allocated at this point.
392 	 * That occurs at commit time. Reuse the seq field to pass in the seq
393 	 * of a prejournaled key.
394 	 */
395 	if (flags & BTREE_UPDATE_PREJOURNAL)
396 		seq = trans->journal_res.seq;
397 
398 	n = (struct btree_insert_entry) {
399 		.flags		= flags,
400 		.bkey_type	= __btree_node_type(path->level, path->btree_id),
401 		.btree_id	= path->btree_id,
402 		.level		= path->level,
403 		.cached		= path->cached,
404 		.path		= path,
405 		.k		= k,
406 		.seq		= seq,
407 		.ip_allocated	= ip,
408 	};
409 
410 #ifdef CONFIG_BCACHEFS_DEBUG
411 	trans_for_each_update(trans, i)
412 		BUG_ON(i != trans->updates &&
413 		       btree_insert_entry_cmp(i - 1, i) >= 0);
414 #endif
415 
416 	/*
417 	 * Pending updates are kept sorted: first, find position of new update,
418 	 * then delete/trim any updates the new update overwrites:
419 	 */
420 	trans_for_each_update(trans, i) {
421 		cmp = btree_insert_entry_cmp(&n, i);
422 		if (cmp <= 0)
423 			break;
424 	}
425 
426 	if (!cmp && i < trans->updates + trans->nr_updates) {
427 		EBUG_ON(i->insert_trigger_run || i->overwrite_trigger_run);
428 
429 		bch2_path_put(trans, i->path, true);
430 		i->flags	= n.flags;
431 		i->cached	= n.cached;
432 		i->k		= n.k;
433 		i->path		= n.path;
434 		i->seq		= n.seq;
435 		i->ip_allocated	= n.ip_allocated;
436 	} else {
437 		array_insert_item(trans->updates, trans->nr_updates,
438 				  i - trans->updates, n);
439 
440 		i->old_v = bch2_btree_path_peek_slot_exact(path, &i->old_k).v;
441 		i->old_btree_u64s = !bkey_deleted(&i->old_k) ? i->old_k.u64s : 0;
442 
443 		if (unlikely(trans->journal_replay_not_finished)) {
444 			struct bkey_i *j_k =
445 				bch2_journal_keys_peek_slot(c, n.btree_id, n.level, k->k.p);
446 
447 			if (j_k) {
448 				i->old_k = j_k->k;
449 				i->old_v = &j_k->v;
450 			}
451 		}
452 	}
453 
454 	__btree_path_get(i->path, true);
455 
456 	/*
457 	 * If a key is present in the key cache, it must also exist in the
458 	 * btree - this is necessary for cache coherency. When iterating over
459 	 * a btree that's cached in the key cache, the btree iter code checks
460 	 * the key cache - but the key has to exist in the btree for that to
461 	 * work:
462 	 */
463 	if (path->cached && bkey_deleted(&i->old_k))
464 		return flush_new_cached_update(trans, path, i, flags, ip);
465 
466 	return 0;
467 }
468 
469 static noinline int bch2_trans_update_get_key_cache(struct btree_trans *trans,
470 						    struct btree_iter *iter,
471 						    struct btree_path *path)
472 {
473 	if (!iter->key_cache_path ||
474 	    !iter->key_cache_path->should_be_locked ||
475 	    !bpos_eq(iter->key_cache_path->pos, iter->pos)) {
476 		struct bkey_cached *ck;
477 		int ret;
478 
479 		if (!iter->key_cache_path)
480 			iter->key_cache_path =
481 				bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
482 					      BTREE_ITER_INTENT|
483 					      BTREE_ITER_CACHED, _THIS_IP_);
484 
485 		iter->key_cache_path =
486 			bch2_btree_path_set_pos(trans, iter->key_cache_path, path->pos,
487 						iter->flags & BTREE_ITER_INTENT,
488 						_THIS_IP_);
489 
490 		ret = bch2_btree_path_traverse(trans, iter->key_cache_path,
491 					       BTREE_ITER_CACHED);
492 		if (unlikely(ret))
493 			return ret;
494 
495 		ck = (void *) iter->key_cache_path->l[0].b;
496 
497 		if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
498 			trace_and_count(trans->c, trans_restart_key_cache_raced, trans, _RET_IP_);
499 			return btree_trans_restart(trans, BCH_ERR_transaction_restart_key_cache_raced);
500 		}
501 
502 		btree_path_set_should_be_locked(iter->key_cache_path);
503 	}
504 
505 	return 0;
506 }
507 
508 int __must_check bch2_trans_update(struct btree_trans *trans, struct btree_iter *iter,
509 				   struct bkey_i *k, enum btree_update_flags flags)
510 {
511 	struct btree_path *path = iter->update_path ?: iter->path;
512 	int ret;
513 
514 	if (iter->flags & BTREE_ITER_IS_EXTENTS)
515 		return bch2_trans_update_extent(trans, iter, k, flags);
516 
517 	if (bkey_deleted(&k->k) &&
518 	    !(flags & BTREE_UPDATE_KEY_CACHE_RECLAIM) &&
519 	    (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)) {
520 		ret = need_whiteout_for_snapshot(trans, iter->btree_id, k->k.p);
521 		if (unlikely(ret < 0))
522 			return ret;
523 
524 		if (ret)
525 			k->k.type = KEY_TYPE_whiteout;
526 	}
527 
528 	/*
529 	 * Ensure that updates to cached btrees go to the key cache:
530 	 */
531 	if (!(flags & BTREE_UPDATE_KEY_CACHE_RECLAIM) &&
532 	    !path->cached &&
533 	    !path->level &&
534 	    btree_id_cached(trans->c, path->btree_id)) {
535 		ret = bch2_trans_update_get_key_cache(trans, iter, path);
536 		if (ret)
537 			return ret;
538 
539 		path = iter->key_cache_path;
540 	}
541 
542 	return bch2_trans_update_by_path(trans, path, k, flags, _RET_IP_);
543 }
544 
545 /*
546  * Add a transaction update for a key that has already been journaled.
547  */
548 int __must_check bch2_trans_update_seq(struct btree_trans *trans, u64 seq,
549 				       struct btree_iter *iter, struct bkey_i *k,
550 				       enum btree_update_flags flags)
551 {
552 	trans->journal_res.seq = seq;
553 	return bch2_trans_update(trans, iter, k, flags|BTREE_UPDATE_NOJOURNAL|
554 						 BTREE_UPDATE_PREJOURNAL);
555 }
556 
557 static noinline int bch2_btree_insert_clone_trans(struct btree_trans *trans,
558 						  enum btree_id btree,
559 						  struct bkey_i *k)
560 {
561 	struct bkey_i *n = bch2_trans_kmalloc(trans, bkey_bytes(&k->k));
562 	int ret = PTR_ERR_OR_ZERO(n);
563 	if (ret)
564 		return ret;
565 
566 	bkey_copy(n, k);
567 	return bch2_btree_insert_trans(trans, btree, n, 0);
568 }
569 
570 int __must_check bch2_trans_update_buffered(struct btree_trans *trans,
571 					    enum btree_id btree,
572 					    struct bkey_i *k)
573 {
574 	struct btree_write_buffered_key *i;
575 	int ret;
576 
577 	EBUG_ON(trans->nr_wb_updates > trans->wb_updates_size);
578 	EBUG_ON(k->k.u64s > BTREE_WRITE_BUFERED_U64s_MAX);
579 
580 	if (unlikely(trans->journal_replay_not_finished))
581 		return bch2_btree_insert_clone_trans(trans, btree, k);
582 
583 	trans_for_each_wb_update(trans, i) {
584 		if (i->btree == btree && bpos_eq(i->k.k.p, k->k.p)) {
585 			bkey_copy(&i->k, k);
586 			return 0;
587 		}
588 	}
589 
590 	if (!trans->wb_updates ||
591 	    trans->nr_wb_updates == trans->wb_updates_size) {
592 		struct btree_write_buffered_key *u;
593 
594 		if (trans->nr_wb_updates == trans->wb_updates_size) {
595 			struct btree_transaction_stats *s = btree_trans_stats(trans);
596 
597 			BUG_ON(trans->wb_updates_size > U8_MAX / 2);
598 			trans->wb_updates_size = max(1, trans->wb_updates_size * 2);
599 			if (s)
600 				s->wb_updates_size = trans->wb_updates_size;
601 		}
602 
603 		u = bch2_trans_kmalloc_nomemzero(trans,
604 					trans->wb_updates_size *
605 					sizeof(struct btree_write_buffered_key));
606 		ret = PTR_ERR_OR_ZERO(u);
607 		if (ret)
608 			return ret;
609 
610 		if (trans->nr_wb_updates)
611 			memcpy(u, trans->wb_updates, trans->nr_wb_updates *
612 			       sizeof(struct btree_write_buffered_key));
613 		trans->wb_updates = u;
614 	}
615 
616 	trans->wb_updates[trans->nr_wb_updates] = (struct btree_write_buffered_key) {
617 		.btree	= btree,
618 	};
619 
620 	bkey_copy(&trans->wb_updates[trans->nr_wb_updates].k, k);
621 	trans->nr_wb_updates++;
622 
623 	return 0;
624 }
625 
626 int bch2_bkey_get_empty_slot(struct btree_trans *trans, struct btree_iter *iter,
627 			     enum btree_id btree, struct bpos end)
628 {
629 	struct bkey_s_c k;
630 	int ret = 0;
631 
632 	bch2_trans_iter_init(trans, iter, btree, POS_MAX, BTREE_ITER_INTENT);
633 	k = bch2_btree_iter_prev(iter);
634 	ret = bkey_err(k);
635 	if (ret)
636 		goto err;
637 
638 	bch2_btree_iter_advance(iter);
639 	k = bch2_btree_iter_peek_slot(iter);
640 	ret = bkey_err(k);
641 	if (ret)
642 		goto err;
643 
644 	BUG_ON(k.k->type != KEY_TYPE_deleted);
645 
646 	if (bkey_gt(k.k->p, end)) {
647 		ret = -BCH_ERR_ENOSPC_btree_slot;
648 		goto err;
649 	}
650 
651 	return 0;
652 err:
653 	bch2_trans_iter_exit(trans, iter);
654 	return ret;
655 }
656 
657 void bch2_trans_commit_hook(struct btree_trans *trans,
658 			    struct btree_trans_commit_hook *h)
659 {
660 	h->next = trans->hooks;
661 	trans->hooks = h;
662 }
663 
664 int bch2_btree_insert_nonextent(struct btree_trans *trans,
665 				enum btree_id btree, struct bkey_i *k,
666 				enum btree_update_flags flags)
667 {
668 	struct btree_iter iter;
669 	int ret;
670 
671 	bch2_trans_iter_init(trans, &iter, btree, k->k.p,
672 			     BTREE_ITER_CACHED|
673 			     BTREE_ITER_NOT_EXTENTS|
674 			     BTREE_ITER_INTENT);
675 	ret   = bch2_btree_iter_traverse(&iter) ?:
676 		bch2_trans_update(trans, &iter, k, flags);
677 	bch2_trans_iter_exit(trans, &iter);
678 	return ret;
679 }
680 
681 int bch2_btree_insert_trans(struct btree_trans *trans, enum btree_id id,
682 			    struct bkey_i *k, enum btree_update_flags flags)
683 {
684 	struct btree_iter iter;
685 	int ret;
686 
687 	bch2_trans_iter_init(trans, &iter, id, bkey_start_pos(&k->k),
688 			     BTREE_ITER_CACHED|
689 			     BTREE_ITER_INTENT);
690 	ret   = bch2_btree_iter_traverse(&iter) ?:
691 		bch2_trans_update(trans, &iter, k, flags);
692 	bch2_trans_iter_exit(trans, &iter);
693 	return ret;
694 }
695 
696 /**
697  * bch2_btree_insert - insert keys into the extent btree
698  * @c:			pointer to struct bch_fs
699  * @id:			btree to insert into
700  * @k:			key to insert
701  * @disk_res:		must be non-NULL whenever inserting or potentially
702  *			splitting data extents
703  * @flags:		transaction commit flags
704  *
705  * Returns:		0 on success, error code on failure
706  */
707 int bch2_btree_insert(struct bch_fs *c, enum btree_id id, struct bkey_i *k,
708 		      struct disk_reservation *disk_res, int flags)
709 {
710 	return bch2_trans_do(c, disk_res, NULL, flags,
711 			     bch2_btree_insert_trans(trans, id, k, 0));
712 }
713 
714 int bch2_btree_delete_extent_at(struct btree_trans *trans, struct btree_iter *iter,
715 				unsigned len, unsigned update_flags)
716 {
717 	struct bkey_i *k;
718 
719 	k = bch2_trans_kmalloc(trans, sizeof(*k));
720 	if (IS_ERR(k))
721 		return PTR_ERR(k);
722 
723 	bkey_init(&k->k);
724 	k->k.p = iter->pos;
725 	bch2_key_resize(&k->k, len);
726 	return bch2_trans_update(trans, iter, k, update_flags);
727 }
728 
729 int bch2_btree_delete_at(struct btree_trans *trans,
730 			 struct btree_iter *iter, unsigned update_flags)
731 {
732 	return bch2_btree_delete_extent_at(trans, iter, 0, update_flags);
733 }
734 
735 int bch2_btree_delete_at_buffered(struct btree_trans *trans,
736 				  enum btree_id btree, struct bpos pos)
737 {
738 	struct bkey_i *k;
739 
740 	k = bch2_trans_kmalloc(trans, sizeof(*k));
741 	if (IS_ERR(k))
742 		return PTR_ERR(k);
743 
744 	bkey_init(&k->k);
745 	k->k.p = pos;
746 	return bch2_trans_update_buffered(trans, btree, k);
747 }
748 
749 int bch2_btree_delete(struct btree_trans *trans,
750 		      enum btree_id btree, struct bpos pos,
751 		      unsigned update_flags)
752 {
753 	struct btree_iter iter;
754 	int ret;
755 
756 	bch2_trans_iter_init(trans, &iter, btree, pos,
757 			     BTREE_ITER_CACHED|
758 			     BTREE_ITER_INTENT);
759 	ret   = bch2_btree_iter_traverse(&iter) ?:
760 		bch2_btree_delete_at(trans, &iter, update_flags);
761 	bch2_trans_iter_exit(trans, &iter);
762 
763 	return ret;
764 }
765 
766 int bch2_btree_delete_range_trans(struct btree_trans *trans, enum btree_id id,
767 				  struct bpos start, struct bpos end,
768 				  unsigned update_flags,
769 				  u64 *journal_seq)
770 {
771 	u32 restart_count = trans->restart_count;
772 	struct btree_iter iter;
773 	struct bkey_s_c k;
774 	int ret = 0;
775 
776 	bch2_trans_iter_init(trans, &iter, id, start, BTREE_ITER_INTENT);
777 	while ((k = bch2_btree_iter_peek_upto(&iter, end)).k) {
778 		struct disk_reservation disk_res =
779 			bch2_disk_reservation_init(trans->c, 0);
780 		struct bkey_i delete;
781 
782 		ret = bkey_err(k);
783 		if (ret)
784 			goto err;
785 
786 		bkey_init(&delete.k);
787 
788 		/*
789 		 * This could probably be more efficient for extents:
790 		 */
791 
792 		/*
793 		 * For extents, iter.pos won't necessarily be the same as
794 		 * bkey_start_pos(k.k) (for non extents they always will be the
795 		 * same). It's important that we delete starting from iter.pos
796 		 * because the range we want to delete could start in the middle
797 		 * of k.
798 		 *
799 		 * (bch2_btree_iter_peek() does guarantee that iter.pos >=
800 		 * bkey_start_pos(k.k)).
801 		 */
802 		delete.k.p = iter.pos;
803 
804 		if (iter.flags & BTREE_ITER_IS_EXTENTS)
805 			bch2_key_resize(&delete.k,
806 					bpos_min(end, k.k->p).offset -
807 					iter.pos.offset);
808 
809 		ret   = bch2_trans_update(trans, &iter, &delete, update_flags) ?:
810 			bch2_trans_commit(trans, &disk_res, journal_seq,
811 					  BTREE_INSERT_NOFAIL);
812 		bch2_disk_reservation_put(trans->c, &disk_res);
813 err:
814 		/*
815 		 * the bch2_trans_begin() call is in a weird place because we
816 		 * need to call it after every transaction commit, to avoid path
817 		 * overflow, but don't want to call it if the delete operation
818 		 * is a no-op and we have no work to do:
819 		 */
820 		bch2_trans_begin(trans);
821 
822 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
823 			ret = 0;
824 		if (ret)
825 			break;
826 	}
827 	bch2_trans_iter_exit(trans, &iter);
828 
829 	return ret ?: trans_was_restarted(trans, restart_count);
830 }
831 
832 /*
833  * bch_btree_delete_range - delete everything within a given range
834  *
835  * Range is a half open interval - [start, end)
836  */
837 int bch2_btree_delete_range(struct bch_fs *c, enum btree_id id,
838 			    struct bpos start, struct bpos end,
839 			    unsigned update_flags,
840 			    u64 *journal_seq)
841 {
842 	int ret = bch2_trans_run(c,
843 			bch2_btree_delete_range_trans(trans, id, start, end,
844 						      update_flags, journal_seq));
845 	if (ret == -BCH_ERR_transaction_restart_nested)
846 		ret = 0;
847 	return ret;
848 }
849 
850 int bch2_btree_bit_mod(struct btree_trans *trans, enum btree_id btree,
851 		       struct bpos pos, bool set)
852 {
853 	struct bkey_i *k;
854 	int ret = 0;
855 
856 	k = bch2_trans_kmalloc_nomemzero(trans, sizeof(*k));
857 	ret = PTR_ERR_OR_ZERO(k);
858 	if (unlikely(ret))
859 		return ret;
860 
861 	bkey_init(&k->k);
862 	k->k.type = set ? KEY_TYPE_set : KEY_TYPE_deleted;
863 	k->k.p = pos;
864 
865 	return bch2_trans_update_buffered(trans, btree, k);
866 }
867 
868 __printf(2, 0)
869 static int __bch2_trans_log_msg(darray_u64 *entries, const char *fmt, va_list args)
870 {
871 	struct printbuf buf = PRINTBUF;
872 	struct jset_entry_log *l;
873 	unsigned u64s;
874 	int ret;
875 
876 	prt_vprintf(&buf, fmt, args);
877 	ret = buf.allocation_failure ? -BCH_ERR_ENOMEM_trans_log_msg : 0;
878 	if (ret)
879 		goto err;
880 
881 	u64s = DIV_ROUND_UP(buf.pos, sizeof(u64));
882 
883 	ret = darray_make_room(entries, jset_u64s(u64s));
884 	if (ret)
885 		goto err;
886 
887 	l = (void *) &darray_top(*entries);
888 	l->entry.u64s		= cpu_to_le16(u64s);
889 	l->entry.btree_id	= 0;
890 	l->entry.level		= 1;
891 	l->entry.type		= BCH_JSET_ENTRY_log;
892 	l->entry.pad[0]		= 0;
893 	l->entry.pad[1]		= 0;
894 	l->entry.pad[2]		= 0;
895 	memcpy(l->d, buf.buf, buf.pos);
896 	while (buf.pos & 7)
897 		l->d[buf.pos++] = '\0';
898 
899 	entries->nr += jset_u64s(u64s);
900 err:
901 	printbuf_exit(&buf);
902 	return ret;
903 }
904 
905 __printf(3, 0)
906 static int
907 __bch2_fs_log_msg(struct bch_fs *c, unsigned commit_flags, const char *fmt,
908 		  va_list args)
909 {
910 	int ret;
911 
912 	if (!test_bit(JOURNAL_STARTED, &c->journal.flags)) {
913 		ret = __bch2_trans_log_msg(&c->journal.early_journal_entries, fmt, args);
914 	} else {
915 		ret = bch2_trans_do(c, NULL, NULL,
916 			BTREE_INSERT_LAZY_RW|commit_flags,
917 			__bch2_trans_log_msg(&trans->extra_journal_entries, fmt, args));
918 	}
919 
920 	return ret;
921 }
922 
923 __printf(2, 3)
924 int bch2_fs_log_msg(struct bch_fs *c, const char *fmt, ...)
925 {
926 	va_list args;
927 	int ret;
928 
929 	va_start(args, fmt);
930 	ret = __bch2_fs_log_msg(c, 0, fmt, args);
931 	va_end(args);
932 	return ret;
933 }
934 
935 /*
936  * Use for logging messages during recovery to enable reserved space and avoid
937  * blocking.
938  */
939 __printf(2, 3)
940 int bch2_journal_log_msg(struct bch_fs *c, const char *fmt, ...)
941 {
942 	va_list args;
943 	int ret;
944 
945 	va_start(args, fmt);
946 	ret = __bch2_fs_log_msg(c, BCH_WATERMARK_reclaim, fmt, args);
947 	va_end(args);
948 	return ret;
949 }
950