xref: /linux/fs/bcachefs/btree_node_scan.c (revision a3a02a52bcfcbcc4a637d4b68bf1bc391c9fad02)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include "bcachefs.h"
4 #include "btree_cache.h"
5 #include "btree_io.h"
6 #include "btree_journal_iter.h"
7 #include "btree_node_scan.h"
8 #include "btree_update_interior.h"
9 #include "buckets.h"
10 #include "error.h"
11 #include "journal_io.h"
12 #include "recovery_passes.h"
13 
14 #include <linux/kthread.h>
15 #include <linux/sort.h>
16 
17 struct find_btree_nodes_worker {
18 	struct closure		*cl;
19 	struct find_btree_nodes	*f;
20 	struct bch_dev		*ca;
21 };
22 
23 static void found_btree_node_to_text(struct printbuf *out, struct bch_fs *c, const struct found_btree_node *n)
24 {
25 	prt_printf(out, "%s l=%u seq=%u journal_seq=%llu cookie=%llx ",
26 		   bch2_btree_id_str(n->btree_id), n->level, n->seq,
27 		   n->journal_seq, n->cookie);
28 	bch2_bpos_to_text(out, n->min_key);
29 	prt_str(out, "-");
30 	bch2_bpos_to_text(out, n->max_key);
31 
32 	if (n->range_updated)
33 		prt_str(out, " range updated");
34 	if (n->overwritten)
35 		prt_str(out, " overwritten");
36 
37 	for (unsigned i = 0; i < n->nr_ptrs; i++) {
38 		prt_char(out, ' ');
39 		bch2_extent_ptr_to_text(out, c, n->ptrs + i);
40 	}
41 }
42 
43 static void found_btree_nodes_to_text(struct printbuf *out, struct bch_fs *c, found_btree_nodes nodes)
44 {
45 	printbuf_indent_add(out, 2);
46 	darray_for_each(nodes, i) {
47 		found_btree_node_to_text(out, c, i);
48 		prt_newline(out);
49 	}
50 	printbuf_indent_sub(out, 2);
51 }
52 
53 static void found_btree_node_to_key(struct bkey_i *k, const struct found_btree_node *f)
54 {
55 	struct bkey_i_btree_ptr_v2 *bp = bkey_btree_ptr_v2_init(k);
56 
57 	set_bkey_val_u64s(&bp->k, sizeof(struct bch_btree_ptr_v2) / sizeof(u64) + f->nr_ptrs);
58 	bp->k.p			= f->max_key;
59 	bp->v.seq		= cpu_to_le64(f->cookie);
60 	bp->v.sectors_written	= 0;
61 	bp->v.flags		= 0;
62 	bp->v.sectors_written	= cpu_to_le16(f->sectors_written);
63 	bp->v.min_key		= f->min_key;
64 	SET_BTREE_PTR_RANGE_UPDATED(&bp->v, f->range_updated);
65 	memcpy(bp->v.start, f->ptrs, sizeof(struct bch_extent_ptr) * f->nr_ptrs);
66 }
67 
68 static inline u64 bkey_journal_seq(struct bkey_s_c k)
69 {
70 	switch (k.k->type) {
71 	case KEY_TYPE_inode_v3:
72 		return le64_to_cpu(bkey_s_c_to_inode_v3(k).v->bi_journal_seq);
73 	default:
74 		return 0;
75 	}
76 }
77 
78 static bool found_btree_node_is_readable(struct btree_trans *trans,
79 					 struct found_btree_node *f)
80 {
81 	struct { __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX); } tmp;
82 
83 	found_btree_node_to_key(&tmp.k, f);
84 
85 	struct btree *b = bch2_btree_node_get_noiter(trans, &tmp.k, f->btree_id, f->level, false);
86 	bool ret = !IS_ERR_OR_NULL(b);
87 	if (!ret)
88 		return ret;
89 
90 	f->sectors_written = b->written;
91 	f->journal_seq = le64_to_cpu(b->data->keys.journal_seq);
92 
93 	struct bkey_s_c k;
94 	struct bkey unpacked;
95 	struct btree_node_iter iter;
96 	for_each_btree_node_key_unpack(b, k, &iter, &unpacked)
97 		f->journal_seq = max(f->journal_seq, bkey_journal_seq(k));
98 
99 	six_unlock_read(&b->c.lock);
100 
101 	/*
102 	 * We might update this node's range; if that happens, we need the node
103 	 * to be re-read so the read path can trim keys that are no longer in
104 	 * this node
105 	 */
106 	if (b != btree_node_root(trans->c, b))
107 		bch2_btree_node_evict(trans, &tmp.k);
108 	return ret;
109 }
110 
111 static int found_btree_node_cmp_cookie(const void *_l, const void *_r)
112 {
113 	const struct found_btree_node *l = _l;
114 	const struct found_btree_node *r = _r;
115 
116 	return  cmp_int(l->btree_id,	r->btree_id) ?:
117 		cmp_int(l->level,	r->level) ?:
118 		cmp_int(l->cookie,	r->cookie);
119 }
120 
121 /*
122  * Given two found btree nodes, if their sequence numbers are equal, take the
123  * one that's readable:
124  */
125 static int found_btree_node_cmp_time(const struct found_btree_node *l,
126 				     const struct found_btree_node *r)
127 {
128 	return  cmp_int(l->seq, r->seq) ?:
129 		cmp_int(l->journal_seq, r->journal_seq);
130 }
131 
132 static int found_btree_node_cmp_pos(const void *_l, const void *_r)
133 {
134 	const struct found_btree_node *l = _l;
135 	const struct found_btree_node *r = _r;
136 
137 	return  cmp_int(l->btree_id,	r->btree_id) ?:
138 	       -cmp_int(l->level,	r->level) ?:
139 		bpos_cmp(l->min_key,	r->min_key) ?:
140 	       -found_btree_node_cmp_time(l, r);
141 }
142 
143 static void try_read_btree_node(struct find_btree_nodes *f, struct bch_dev *ca,
144 				struct bio *bio, struct btree_node *bn, u64 offset)
145 {
146 	struct bch_fs *c = container_of(f, struct bch_fs, found_btree_nodes);
147 
148 	bio_reset(bio, ca->disk_sb.bdev, REQ_OP_READ);
149 	bio->bi_iter.bi_sector	= offset;
150 	bch2_bio_map(bio, bn, PAGE_SIZE);
151 
152 	submit_bio_wait(bio);
153 	if (bch2_dev_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_read,
154 			       "IO error in try_read_btree_node() at %llu: %s",
155 			       offset, bch2_blk_status_to_str(bio->bi_status)))
156 		return;
157 
158 	if (le64_to_cpu(bn->magic) != bset_magic(c))
159 		return;
160 
161 	if (bch2_csum_type_is_encryption(BSET_CSUM_TYPE(&bn->keys))) {
162 		struct nonce nonce = btree_nonce(&bn->keys, 0);
163 		unsigned bytes = (void *) &bn->keys - (void *) &bn->flags;
164 
165 		bch2_encrypt(c, BSET_CSUM_TYPE(&bn->keys), nonce, &bn->flags, bytes);
166 	}
167 
168 	if (btree_id_is_alloc(BTREE_NODE_ID(bn)))
169 		return;
170 
171 	if (BTREE_NODE_LEVEL(bn) >= BTREE_MAX_DEPTH)
172 		return;
173 
174 	rcu_read_lock();
175 	struct found_btree_node n = {
176 		.btree_id	= BTREE_NODE_ID(bn),
177 		.level		= BTREE_NODE_LEVEL(bn),
178 		.seq		= BTREE_NODE_SEQ(bn),
179 		.cookie		= le64_to_cpu(bn->keys.seq),
180 		.min_key	= bn->min_key,
181 		.max_key	= bn->max_key,
182 		.nr_ptrs	= 1,
183 		.ptrs[0].type	= 1 << BCH_EXTENT_ENTRY_ptr,
184 		.ptrs[0].offset	= offset,
185 		.ptrs[0].dev	= ca->dev_idx,
186 		.ptrs[0].gen	= *bucket_gen(ca, sector_to_bucket(ca, offset)),
187 	};
188 	rcu_read_unlock();
189 
190 	if (bch2_trans_run(c, found_btree_node_is_readable(trans, &n))) {
191 		mutex_lock(&f->lock);
192 		if (BSET_BIG_ENDIAN(&bn->keys) != CPU_BIG_ENDIAN) {
193 			bch_err(c, "try_read_btree_node() can't handle endian conversion");
194 			f->ret = -EINVAL;
195 			goto unlock;
196 		}
197 
198 		if (darray_push(&f->nodes, n))
199 			f->ret = -ENOMEM;
200 unlock:
201 		mutex_unlock(&f->lock);
202 	}
203 }
204 
205 static int read_btree_nodes_worker(void *p)
206 {
207 	struct find_btree_nodes_worker *w = p;
208 	struct bch_fs *c = container_of(w->f, struct bch_fs, found_btree_nodes);
209 	struct bch_dev *ca = w->ca;
210 	void *buf = (void *) __get_free_page(GFP_KERNEL);
211 	struct bio *bio = bio_alloc(NULL, 1, 0, GFP_KERNEL);
212 	unsigned long last_print = jiffies;
213 
214 	if (!buf || !bio) {
215 		bch_err(c, "read_btree_nodes_worker: error allocating bio/buf");
216 		w->f->ret = -ENOMEM;
217 		goto err;
218 	}
219 
220 	for (u64 bucket = ca->mi.first_bucket; bucket < ca->mi.nbuckets; bucket++)
221 		for (unsigned bucket_offset = 0;
222 		     bucket_offset + btree_sectors(c) <= ca->mi.bucket_size;
223 		     bucket_offset += btree_sectors(c)) {
224 			if (time_after(jiffies, last_print + HZ * 30)) {
225 				u64 cur_sector = bucket * ca->mi.bucket_size + bucket_offset;
226 				u64 end_sector = ca->mi.nbuckets * ca->mi.bucket_size;
227 
228 				bch_info(ca, "%s: %2u%% done", __func__,
229 					 (unsigned) div64_u64(cur_sector * 100, end_sector));
230 				last_print = jiffies;
231 			}
232 
233 			u64 sector = bucket * ca->mi.bucket_size + bucket_offset;
234 
235 			if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_mi_btree_bitmap &&
236 			    !bch2_dev_btree_bitmap_marked_sectors(ca, sector, btree_sectors(c)))
237 				continue;
238 
239 			try_read_btree_node(w->f, ca, bio, buf, sector);
240 		}
241 err:
242 	bio_put(bio);
243 	free_page((unsigned long) buf);
244 	percpu_ref_get(&ca->io_ref);
245 	closure_put(w->cl);
246 	kfree(w);
247 	return 0;
248 }
249 
250 static int read_btree_nodes(struct find_btree_nodes *f)
251 {
252 	struct bch_fs *c = container_of(f, struct bch_fs, found_btree_nodes);
253 	struct closure cl;
254 	int ret = 0;
255 
256 	closure_init_stack(&cl);
257 
258 	for_each_online_member(c, ca) {
259 		if (!(ca->mi.data_allowed & BIT(BCH_DATA_btree)))
260 			continue;
261 
262 		struct find_btree_nodes_worker *w = kmalloc(sizeof(*w), GFP_KERNEL);
263 		struct task_struct *t;
264 
265 		if (!w) {
266 			percpu_ref_put(&ca->io_ref);
267 			ret = -ENOMEM;
268 			goto err;
269 		}
270 
271 		percpu_ref_get(&ca->io_ref);
272 		closure_get(&cl);
273 		w->cl		= &cl;
274 		w->f		= f;
275 		w->ca		= ca;
276 
277 		t = kthread_run(read_btree_nodes_worker, w, "read_btree_nodes/%s", ca->name);
278 		ret = IS_ERR_OR_NULL(t);
279 		if (ret) {
280 			percpu_ref_put(&ca->io_ref);
281 			closure_put(&cl);
282 			f->ret = ret;
283 			bch_err(c, "error starting kthread: %i", ret);
284 			break;
285 		}
286 	}
287 err:
288 	closure_sync(&cl);
289 	return f->ret ?: ret;
290 }
291 
292 static void bubble_up(struct found_btree_node *n, struct found_btree_node *end)
293 {
294 	while (n + 1 < end &&
295 	       found_btree_node_cmp_pos(n, n + 1) > 0) {
296 		swap(n[0], n[1]);
297 		n++;
298 	}
299 }
300 
301 static int handle_overwrites(struct bch_fs *c,
302 			     struct found_btree_node *start,
303 			     struct found_btree_node *end)
304 {
305 	struct found_btree_node *n;
306 again:
307 	for (n = start + 1;
308 	     n < end &&
309 	     n->btree_id	== start->btree_id &&
310 	     n->level		== start->level &&
311 	     bpos_lt(n->min_key, start->max_key);
312 	     n++)  {
313 		int cmp = found_btree_node_cmp_time(start, n);
314 
315 		if (cmp > 0) {
316 			if (bpos_cmp(start->max_key, n->max_key) >= 0)
317 				n->overwritten = true;
318 			else {
319 				n->range_updated = true;
320 				n->min_key = bpos_successor(start->max_key);
321 				n->range_updated = true;
322 				bubble_up(n, end);
323 				goto again;
324 			}
325 		} else if (cmp < 0) {
326 			BUG_ON(bpos_cmp(n->min_key, start->min_key) <= 0);
327 
328 			start->max_key = bpos_predecessor(n->min_key);
329 			start->range_updated = true;
330 		} else if (n->level) {
331 			n->overwritten = true;
332 		} else {
333 			if (bpos_cmp(start->max_key, n->max_key) >= 0)
334 				n->overwritten = true;
335 			else {
336 				n->range_updated = true;
337 				n->min_key = bpos_successor(start->max_key);
338 				n->range_updated = true;
339 				bubble_up(n, end);
340 				goto again;
341 			}
342 		}
343 	}
344 
345 	return 0;
346 }
347 
348 int bch2_scan_for_btree_nodes(struct bch_fs *c)
349 {
350 	struct find_btree_nodes *f = &c->found_btree_nodes;
351 	struct printbuf buf = PRINTBUF;
352 	size_t dst;
353 	int ret = 0;
354 
355 	if (f->nodes.nr)
356 		return 0;
357 
358 	mutex_init(&f->lock);
359 
360 	ret = read_btree_nodes(f);
361 	if (ret)
362 		return ret;
363 
364 	if (!f->nodes.nr) {
365 		bch_err(c, "%s: no btree nodes found", __func__);
366 		ret = -EINVAL;
367 		goto err;
368 	}
369 
370 	if (0 && c->opts.verbose) {
371 		printbuf_reset(&buf);
372 		prt_printf(&buf, "%s: nodes found:\n", __func__);
373 		found_btree_nodes_to_text(&buf, c, f->nodes);
374 		bch2_print_string_as_lines(KERN_INFO, buf.buf);
375 	}
376 
377 	sort(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_cookie, NULL);
378 
379 	dst = 0;
380 	darray_for_each(f->nodes, i) {
381 		struct found_btree_node *prev = dst ? f->nodes.data + dst - 1 : NULL;
382 
383 		if (prev &&
384 		    prev->cookie == i->cookie) {
385 			if (prev->nr_ptrs == ARRAY_SIZE(prev->ptrs)) {
386 				bch_err(c, "%s: found too many replicas for btree node", __func__);
387 				ret = -EINVAL;
388 				goto err;
389 			}
390 			prev->ptrs[prev->nr_ptrs++] = i->ptrs[0];
391 		} else {
392 			f->nodes.data[dst++] = *i;
393 		}
394 	}
395 	f->nodes.nr = dst;
396 
397 	sort(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_pos, NULL);
398 
399 	if (0 && c->opts.verbose) {
400 		printbuf_reset(&buf);
401 		prt_printf(&buf, "%s: nodes after merging replicas:\n", __func__);
402 		found_btree_nodes_to_text(&buf, c, f->nodes);
403 		bch2_print_string_as_lines(KERN_INFO, buf.buf);
404 	}
405 
406 	dst = 0;
407 	darray_for_each(f->nodes, i) {
408 		if (i->overwritten)
409 			continue;
410 
411 		ret = handle_overwrites(c, i, &darray_top(f->nodes));
412 		if (ret)
413 			goto err;
414 
415 		BUG_ON(i->overwritten);
416 		f->nodes.data[dst++] = *i;
417 	}
418 	f->nodes.nr = dst;
419 
420 	if (c->opts.verbose) {
421 		printbuf_reset(&buf);
422 		prt_printf(&buf, "%s: nodes found after overwrites:\n", __func__);
423 		found_btree_nodes_to_text(&buf, c, f->nodes);
424 		bch2_print_string_as_lines(KERN_INFO, buf.buf);
425 	}
426 
427 	eytzinger0_sort(f->nodes.data, f->nodes.nr, sizeof(f->nodes.data[0]), found_btree_node_cmp_pos, NULL);
428 err:
429 	printbuf_exit(&buf);
430 	return ret;
431 }
432 
433 static int found_btree_node_range_start_cmp(const void *_l, const void *_r)
434 {
435 	const struct found_btree_node *l = _l;
436 	const struct found_btree_node *r = _r;
437 
438 	return  cmp_int(l->btree_id,	r->btree_id) ?:
439 	       -cmp_int(l->level,	r->level) ?:
440 		bpos_cmp(l->max_key,	r->min_key);
441 }
442 
443 #define for_each_found_btree_node_in_range(_f, _search, _idx)				\
444 	for (size_t _idx = eytzinger0_find_gt((_f)->nodes.data, (_f)->nodes.nr,		\
445 					sizeof((_f)->nodes.data[0]),			\
446 					found_btree_node_range_start_cmp, &search);	\
447 	     _idx < (_f)->nodes.nr &&							\
448 	     (_f)->nodes.data[_idx].btree_id == _search.btree_id &&			\
449 	     (_f)->nodes.data[_idx].level == _search.level &&				\
450 	     bpos_lt((_f)->nodes.data[_idx].min_key, _search.max_key);			\
451 	     _idx = eytzinger0_next(_idx, (_f)->nodes.nr))
452 
453 bool bch2_btree_node_is_stale(struct bch_fs *c, struct btree *b)
454 {
455 	struct find_btree_nodes *f = &c->found_btree_nodes;
456 
457 	struct found_btree_node search = {
458 		.btree_id	= b->c.btree_id,
459 		.level		= b->c.level,
460 		.min_key	= b->data->min_key,
461 		.max_key	= b->key.k.p,
462 	};
463 
464 	for_each_found_btree_node_in_range(f, search, idx)
465 		if (f->nodes.data[idx].seq > BTREE_NODE_SEQ(b->data))
466 			return true;
467 	return false;
468 }
469 
470 bool bch2_btree_has_scanned_nodes(struct bch_fs *c, enum btree_id btree)
471 {
472 	struct found_btree_node search = {
473 		.btree_id	= btree,
474 		.level		= 0,
475 		.min_key	= POS_MIN,
476 		.max_key	= SPOS_MAX,
477 	};
478 
479 	for_each_found_btree_node_in_range(&c->found_btree_nodes, search, idx)
480 		return true;
481 	return false;
482 }
483 
484 int bch2_get_scanned_nodes(struct bch_fs *c, enum btree_id btree,
485 			   unsigned level, struct bpos node_min, struct bpos node_max)
486 {
487 	if (btree_id_is_alloc(btree))
488 		return 0;
489 
490 	struct find_btree_nodes *f = &c->found_btree_nodes;
491 
492 	int ret = bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_scan_for_btree_nodes);
493 	if (ret)
494 		return ret;
495 
496 	if (c->opts.verbose) {
497 		struct printbuf buf = PRINTBUF;
498 
499 		prt_printf(&buf, "recovering %s l=%u ", bch2_btree_id_str(btree), level);
500 		bch2_bpos_to_text(&buf, node_min);
501 		prt_str(&buf, " - ");
502 		bch2_bpos_to_text(&buf, node_max);
503 
504 		bch_info(c, "%s(): %s", __func__, buf.buf);
505 		printbuf_exit(&buf);
506 	}
507 
508 	struct found_btree_node search = {
509 		.btree_id	= btree,
510 		.level		= level,
511 		.min_key	= node_min,
512 		.max_key	= node_max,
513 	};
514 
515 	for_each_found_btree_node_in_range(f, search, idx) {
516 		struct found_btree_node n = f->nodes.data[idx];
517 
518 		n.range_updated |= bpos_lt(n.min_key, node_min);
519 		n.min_key = bpos_max(n.min_key, node_min);
520 
521 		n.range_updated |= bpos_gt(n.max_key, node_max);
522 		n.max_key = bpos_min(n.max_key, node_max);
523 
524 		struct { __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX); } tmp;
525 
526 		found_btree_node_to_key(&tmp.k, &n);
527 
528 		struct printbuf buf = PRINTBUF;
529 		bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&tmp.k));
530 		bch_verbose(c, "%s(): recovering %s", __func__, buf.buf);
531 		printbuf_exit(&buf);
532 
533 		BUG_ON(bch2_bkey_invalid(c, bkey_i_to_s_c(&tmp.k), BKEY_TYPE_btree, 0, NULL));
534 
535 		ret = bch2_journal_key_insert(c, btree, level + 1, &tmp.k);
536 		if (ret)
537 			return ret;
538 	}
539 
540 	return 0;
541 }
542 
543 void bch2_find_btree_nodes_exit(struct find_btree_nodes *f)
544 {
545 	darray_exit(&f->nodes);
546 }
547