xref: /linux/fs/bcachefs/debug.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Assorted bcachefs debug code
4  *
5  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6  * Copyright 2012 Google, Inc.
7  */
8 
9 #include "bcachefs.h"
10 #include "bkey_methods.h"
11 #include "btree_cache.h"
12 #include "btree_io.h"
13 #include "btree_iter.h"
14 #include "btree_locking.h"
15 #include "btree_update.h"
16 #include "buckets.h"
17 #include "debug.h"
18 #include "error.h"
19 #include "extents.h"
20 #include "fsck.h"
21 #include "inode.h"
22 #include "super.h"
23 
24 #include <linux/console.h>
25 #include <linux/debugfs.h>
26 #include <linux/module.h>
27 #include <linux/random.h>
28 #include <linux/seq_file.h>
29 
30 static struct dentry *bch_debug;
31 
32 static bool bch2_btree_verify_replica(struct bch_fs *c, struct btree *b,
33 				      struct extent_ptr_decoded pick)
34 {
35 	struct btree *v = c->verify_data;
36 	struct btree_node *n_ondisk = c->verify_ondisk;
37 	struct btree_node *n_sorted = c->verify_data->data;
38 	struct bset *sorted, *inmemory = &b->data->keys;
39 	struct bch_dev *ca = bch_dev_bkey_exists(c, pick.ptr.dev);
40 	struct bio *bio;
41 	bool failed = false, saw_error = false;
42 
43 	if (!bch2_dev_get_ioref(ca, READ))
44 		return false;
45 
46 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
47 			       buf_pages(n_sorted, btree_bytes(c)),
48 			       REQ_OP_READ|REQ_META,
49 			       GFP_NOFS,
50 			       &c->btree_bio);
51 	bio->bi_iter.bi_sector	= pick.ptr.offset;
52 	bch2_bio_map(bio, n_sorted, btree_bytes(c));
53 
54 	submit_bio_wait(bio);
55 
56 	bio_put(bio);
57 	percpu_ref_put(&ca->io_ref);
58 
59 	memcpy(n_ondisk, n_sorted, btree_bytes(c));
60 
61 	v->written = 0;
62 	if (bch2_btree_node_read_done(c, ca, v, false, &saw_error) || saw_error)
63 		return false;
64 
65 	n_sorted = c->verify_data->data;
66 	sorted = &n_sorted->keys;
67 
68 	if (inmemory->u64s != sorted->u64s ||
69 	    memcmp(inmemory->start,
70 		   sorted->start,
71 		   vstruct_end(inmemory) - (void *) inmemory->start)) {
72 		unsigned offset = 0, sectors;
73 		struct bset *i;
74 		unsigned j;
75 
76 		console_lock();
77 
78 		printk(KERN_ERR "*** in memory:\n");
79 		bch2_dump_bset(c, b, inmemory, 0);
80 
81 		printk(KERN_ERR "*** read back in:\n");
82 		bch2_dump_bset(c, v, sorted, 0);
83 
84 		while (offset < v->written) {
85 			if (!offset) {
86 				i = &n_ondisk->keys;
87 				sectors = vstruct_blocks(n_ondisk, c->block_bits) <<
88 					c->block_bits;
89 			} else {
90 				struct btree_node_entry *bne =
91 					(void *) n_ondisk + (offset << 9);
92 				i = &bne->keys;
93 
94 				sectors = vstruct_blocks(bne, c->block_bits) <<
95 					c->block_bits;
96 			}
97 
98 			printk(KERN_ERR "*** on disk block %u:\n", offset);
99 			bch2_dump_bset(c, b, i, offset);
100 
101 			offset += sectors;
102 		}
103 
104 		for (j = 0; j < le16_to_cpu(inmemory->u64s); j++)
105 			if (inmemory->_data[j] != sorted->_data[j])
106 				break;
107 
108 		console_unlock();
109 		bch_err(c, "verify failed at key %u", j);
110 
111 		failed = true;
112 	}
113 
114 	if (v->written != b->written) {
115 		bch_err(c, "written wrong: expected %u, got %u",
116 			b->written, v->written);
117 		failed = true;
118 	}
119 
120 	return failed;
121 }
122 
123 void __bch2_btree_verify(struct bch_fs *c, struct btree *b)
124 {
125 	struct bkey_ptrs_c ptrs;
126 	struct extent_ptr_decoded p;
127 	const union bch_extent_entry *entry;
128 	struct btree *v;
129 	struct bset *inmemory = &b->data->keys;
130 	struct bkey_packed *k;
131 	bool failed = false;
132 
133 	if (c->opts.nochanges)
134 		return;
135 
136 	bch2_btree_node_io_lock(b);
137 	mutex_lock(&c->verify_lock);
138 
139 	if (!c->verify_ondisk) {
140 		c->verify_ondisk = kvpmalloc(btree_bytes(c), GFP_KERNEL);
141 		if (!c->verify_ondisk)
142 			goto out;
143 	}
144 
145 	if (!c->verify_data) {
146 		c->verify_data = __bch2_btree_node_mem_alloc(c);
147 		if (!c->verify_data)
148 			goto out;
149 
150 		list_del_init(&c->verify_data->list);
151 	}
152 
153 	BUG_ON(b->nsets != 1);
154 
155 	for (k = inmemory->start; k != vstruct_last(inmemory); k = bkey_p_next(k))
156 		if (k->type == KEY_TYPE_btree_ptr_v2)
157 			((struct bch_btree_ptr_v2 *) bkeyp_val(&b->format, k))->mem_ptr = 0;
158 
159 	v = c->verify_data;
160 	bkey_copy(&v->key, &b->key);
161 	v->c.level	= b->c.level;
162 	v->c.btree_id	= b->c.btree_id;
163 	bch2_btree_keys_init(v);
164 
165 	ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(&b->key));
166 	bkey_for_each_ptr_decode(&b->key.k, ptrs, p, entry)
167 		failed |= bch2_btree_verify_replica(c, b, p);
168 
169 	if (failed) {
170 		struct printbuf buf = PRINTBUF;
171 
172 		bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&b->key));
173 		bch2_fs_fatal_error(c, "btree node verify failed for : %s\n", buf.buf);
174 		printbuf_exit(&buf);
175 	}
176 out:
177 	mutex_unlock(&c->verify_lock);
178 	bch2_btree_node_io_unlock(b);
179 }
180 
181 void bch2_btree_node_ondisk_to_text(struct printbuf *out, struct bch_fs *c,
182 				    const struct btree *b)
183 {
184 	struct btree_node *n_ondisk = NULL;
185 	struct extent_ptr_decoded pick;
186 	struct bch_dev *ca;
187 	struct bio *bio = NULL;
188 	unsigned offset = 0;
189 	int ret;
190 
191 	if (bch2_bkey_pick_read_device(c, bkey_i_to_s_c(&b->key), NULL, &pick) <= 0) {
192 		prt_printf(out, "error getting device to read from: invalid device\n");
193 		return;
194 	}
195 
196 	ca = bch_dev_bkey_exists(c, pick.ptr.dev);
197 	if (!bch2_dev_get_ioref(ca, READ)) {
198 		prt_printf(out, "error getting device to read from: not online\n");
199 		return;
200 	}
201 
202 	n_ondisk = kvpmalloc(btree_bytes(c), GFP_KERNEL);
203 	if (!n_ondisk) {
204 		prt_printf(out, "memory allocation failure\n");
205 		goto out;
206 	}
207 
208 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
209 			       buf_pages(n_ondisk, btree_bytes(c)),
210 			       REQ_OP_READ|REQ_META,
211 			       GFP_NOFS,
212 			       &c->btree_bio);
213 	bio->bi_iter.bi_sector	= pick.ptr.offset;
214 	bch2_bio_map(bio, n_ondisk, btree_bytes(c));
215 
216 	ret = submit_bio_wait(bio);
217 	if (ret) {
218 		prt_printf(out, "IO error reading btree node: %s\n", bch2_err_str(ret));
219 		goto out;
220 	}
221 
222 	while (offset < btree_sectors(c)) {
223 		struct bset *i;
224 		struct nonce nonce;
225 		struct bch_csum csum;
226 		struct bkey_packed *k;
227 		unsigned sectors;
228 
229 		if (!offset) {
230 			i = &n_ondisk->keys;
231 
232 			if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
233 				prt_printf(out, "unknown checksum type at offset %u: %llu\n",
234 					   offset, BSET_CSUM_TYPE(i));
235 				goto out;
236 			}
237 
238 			nonce = btree_nonce(i, offset << 9);
239 			csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, n_ondisk);
240 
241 			if (bch2_crc_cmp(csum, n_ondisk->csum)) {
242 				prt_printf(out, "invalid checksum\n");
243 				goto out;
244 			}
245 
246 			bset_encrypt(c, i, offset << 9);
247 
248 			sectors = vstruct_sectors(n_ondisk, c->block_bits);
249 		} else {
250 			struct btree_node_entry *bne = (void *) n_ondisk + (offset << 9);
251 
252 			i = &bne->keys;
253 
254 			if (i->seq != n_ondisk->keys.seq)
255 				break;
256 
257 			if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
258 				prt_printf(out, "unknown checksum type at offset %u: %llu\n",
259 					   offset, BSET_CSUM_TYPE(i));
260 				goto out;
261 			}
262 
263 			nonce = btree_nonce(i, offset << 9);
264 			csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, bne);
265 
266 			if (bch2_crc_cmp(csum, bne->csum)) {
267 				prt_printf(out, "invalid checksum");
268 				goto out;
269 			}
270 
271 			bset_encrypt(c, i, offset << 9);
272 
273 			sectors = vstruct_sectors(bne, c->block_bits);
274 		}
275 
276 		prt_printf(out, "  offset %u version %u, journal seq %llu\n",
277 			   offset,
278 			   le16_to_cpu(i->version),
279 			   le64_to_cpu(i->journal_seq));
280 		offset += sectors;
281 
282 		printbuf_indent_add(out, 4);
283 
284 		for (k = i->start; k != vstruct_last(i); k = bkey_p_next(k)) {
285 			struct bkey u;
286 
287 			bch2_bkey_val_to_text(out, c, bkey_disassemble(b, k, &u));
288 			prt_newline(out);
289 		}
290 
291 		printbuf_indent_sub(out, 4);
292 	}
293 out:
294 	if (bio)
295 		bio_put(bio);
296 	kvpfree(n_ondisk, btree_bytes(c));
297 	percpu_ref_put(&ca->io_ref);
298 }
299 
300 #ifdef CONFIG_DEBUG_FS
301 
302 /* XXX: bch_fs refcounting */
303 
304 struct dump_iter {
305 	struct bch_fs		*c;
306 	enum btree_id		id;
307 	struct bpos		from;
308 	struct bpos		prev_node;
309 	u64			iter;
310 
311 	struct printbuf		buf;
312 
313 	char __user		*ubuf;	/* destination user buffer */
314 	size_t			size;	/* size of requested read */
315 	ssize_t			ret;	/* bytes read so far */
316 };
317 
318 static ssize_t flush_buf(struct dump_iter *i)
319 {
320 	if (i->buf.pos) {
321 		size_t bytes = min_t(size_t, i->buf.pos, i->size);
322 		int copied = bytes - copy_to_user(i->ubuf, i->buf.buf, bytes);
323 
324 		i->ret	 += copied;
325 		i->ubuf	 += copied;
326 		i->size	 -= copied;
327 		i->buf.pos -= copied;
328 		memmove(i->buf.buf, i->buf.buf + copied, i->buf.pos);
329 
330 		if (copied != bytes)
331 			return -EFAULT;
332 	}
333 
334 	return i->size ? 0 : i->ret;
335 }
336 
337 static int bch2_dump_open(struct inode *inode, struct file *file)
338 {
339 	struct btree_debug *bd = inode->i_private;
340 	struct dump_iter *i;
341 
342 	i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
343 	if (!i)
344 		return -ENOMEM;
345 
346 	file->private_data = i;
347 	i->from = POS_MIN;
348 	i->iter	= 0;
349 	i->c	= container_of(bd, struct bch_fs, btree_debug[bd->id]);
350 	i->id	= bd->id;
351 	i->buf	= PRINTBUF;
352 
353 	return 0;
354 }
355 
356 static int bch2_dump_release(struct inode *inode, struct file *file)
357 {
358 	struct dump_iter *i = file->private_data;
359 
360 	printbuf_exit(&i->buf);
361 	kfree(i);
362 	return 0;
363 }
364 
365 static ssize_t bch2_read_btree(struct file *file, char __user *buf,
366 			       size_t size, loff_t *ppos)
367 {
368 	struct dump_iter *i = file->private_data;
369 	struct btree_trans *trans;
370 	struct btree_iter iter;
371 	struct bkey_s_c k;
372 	ssize_t ret;
373 
374 	i->ubuf = buf;
375 	i->size	= size;
376 	i->ret	= 0;
377 
378 	ret = flush_buf(i);
379 	if (ret)
380 		return ret;
381 
382 	trans = bch2_trans_get(i->c);
383 	ret = for_each_btree_key2(trans, iter, i->id, i->from,
384 				  BTREE_ITER_PREFETCH|
385 				  BTREE_ITER_ALL_SNAPSHOTS, k, ({
386 		bch2_bkey_val_to_text(&i->buf, i->c, k);
387 		prt_newline(&i->buf);
388 		drop_locks_do(trans, flush_buf(i));
389 	}));
390 	i->from = iter.pos;
391 
392 	bch2_trans_put(trans);
393 
394 	if (!ret)
395 		ret = flush_buf(i);
396 
397 	return ret ?: i->ret;
398 }
399 
400 static const struct file_operations btree_debug_ops = {
401 	.owner		= THIS_MODULE,
402 	.open		= bch2_dump_open,
403 	.release	= bch2_dump_release,
404 	.read		= bch2_read_btree,
405 };
406 
407 static ssize_t bch2_read_btree_formats(struct file *file, char __user *buf,
408 				       size_t size, loff_t *ppos)
409 {
410 	struct dump_iter *i = file->private_data;
411 	struct btree_trans *trans;
412 	struct btree_iter iter;
413 	struct btree *b;
414 	ssize_t ret;
415 
416 	i->ubuf = buf;
417 	i->size	= size;
418 	i->ret	= 0;
419 
420 	ret = flush_buf(i);
421 	if (ret)
422 		return ret;
423 
424 	if (bpos_eq(SPOS_MAX, i->from))
425 		return i->ret;
426 
427 	trans = bch2_trans_get(i->c);
428 retry:
429 	bch2_trans_begin(trans);
430 
431 	for_each_btree_node(trans, iter, i->id, i->from, 0, b, ret) {
432 		bch2_btree_node_to_text(&i->buf, i->c, b);
433 		i->from = !bpos_eq(SPOS_MAX, b->key.k.p)
434 			? bpos_successor(b->key.k.p)
435 			: b->key.k.p;
436 
437 		ret = drop_locks_do(trans, flush_buf(i));
438 		if (ret)
439 			break;
440 	}
441 	bch2_trans_iter_exit(trans, &iter);
442 
443 	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
444 		goto retry;
445 
446 	bch2_trans_put(trans);
447 
448 	if (!ret)
449 		ret = flush_buf(i);
450 
451 	return ret ?: i->ret;
452 }
453 
454 static const struct file_operations btree_format_debug_ops = {
455 	.owner		= THIS_MODULE,
456 	.open		= bch2_dump_open,
457 	.release	= bch2_dump_release,
458 	.read		= bch2_read_btree_formats,
459 };
460 
461 static ssize_t bch2_read_bfloat_failed(struct file *file, char __user *buf,
462 				       size_t size, loff_t *ppos)
463 {
464 	struct dump_iter *i = file->private_data;
465 	struct btree_trans *trans;
466 	struct btree_iter iter;
467 	struct bkey_s_c k;
468 	ssize_t ret;
469 
470 	i->ubuf = buf;
471 	i->size	= size;
472 	i->ret	= 0;
473 
474 	ret = flush_buf(i);
475 	if (ret)
476 		return ret;
477 
478 	trans = bch2_trans_get(i->c);
479 
480 	ret = for_each_btree_key2(trans, iter, i->id, i->from,
481 				  BTREE_ITER_PREFETCH|
482 				  BTREE_ITER_ALL_SNAPSHOTS, k, ({
483 		struct btree_path_level *l = &iter.path->l[0];
484 		struct bkey_packed *_k =
485 			bch2_btree_node_iter_peek(&l->iter, l->b);
486 
487 		if (bpos_gt(l->b->key.k.p, i->prev_node)) {
488 			bch2_btree_node_to_text(&i->buf, i->c, l->b);
489 			i->prev_node = l->b->key.k.p;
490 		}
491 
492 		bch2_bfloat_to_text(&i->buf, l->b, _k);
493 		drop_locks_do(trans, flush_buf(i));
494 	}));
495 	i->from = iter.pos;
496 
497 	bch2_trans_put(trans);
498 
499 	if (!ret)
500 		ret = flush_buf(i);
501 
502 	return ret ?: i->ret;
503 }
504 
505 static const struct file_operations bfloat_failed_debug_ops = {
506 	.owner		= THIS_MODULE,
507 	.open		= bch2_dump_open,
508 	.release	= bch2_dump_release,
509 	.read		= bch2_read_bfloat_failed,
510 };
511 
512 static void bch2_cached_btree_node_to_text(struct printbuf *out, struct bch_fs *c,
513 					   struct btree *b)
514 {
515 	if (!out->nr_tabstops)
516 		printbuf_tabstop_push(out, 32);
517 
518 	prt_printf(out, "%px btree=%s l=%u ",
519 	       b,
520 	       bch2_btree_id_str(b->c.btree_id),
521 	       b->c.level);
522 	prt_newline(out);
523 
524 	printbuf_indent_add(out, 2);
525 
526 	bch2_bkey_val_to_text(out, c, bkey_i_to_s_c(&b->key));
527 	prt_newline(out);
528 
529 	prt_printf(out, "flags: ");
530 	prt_tab(out);
531 	prt_bitflags(out, bch2_btree_node_flags, b->flags);
532 	prt_newline(out);
533 
534 	prt_printf(out, "pcpu read locks: ");
535 	prt_tab(out);
536 	prt_printf(out, "%u", b->c.lock.readers != NULL);
537 	prt_newline(out);
538 
539 	prt_printf(out, "written:");
540 	prt_tab(out);
541 	prt_printf(out, "%u", b->written);
542 	prt_newline(out);
543 
544 	prt_printf(out, "writes blocked:");
545 	prt_tab(out);
546 	prt_printf(out, "%u", !list_empty_careful(&b->write_blocked));
547 	prt_newline(out);
548 
549 	prt_printf(out, "will make reachable:");
550 	prt_tab(out);
551 	prt_printf(out, "%lx", b->will_make_reachable);
552 	prt_newline(out);
553 
554 	prt_printf(out, "journal pin %px:", &b->writes[0].journal);
555 	prt_tab(out);
556 	prt_printf(out, "%llu", b->writes[0].journal.seq);
557 	prt_newline(out);
558 
559 	prt_printf(out, "journal pin %px:", &b->writes[1].journal);
560 	prt_tab(out);
561 	prt_printf(out, "%llu", b->writes[1].journal.seq);
562 	prt_newline(out);
563 
564 	printbuf_indent_sub(out, 2);
565 }
566 
567 static ssize_t bch2_cached_btree_nodes_read(struct file *file, char __user *buf,
568 					    size_t size, loff_t *ppos)
569 {
570 	struct dump_iter *i = file->private_data;
571 	struct bch_fs *c = i->c;
572 	bool done = false;
573 	ssize_t ret = 0;
574 
575 	i->ubuf = buf;
576 	i->size	= size;
577 	i->ret	= 0;
578 
579 	do {
580 		struct bucket_table *tbl;
581 		struct rhash_head *pos;
582 		struct btree *b;
583 
584 		ret = flush_buf(i);
585 		if (ret)
586 			return ret;
587 
588 		rcu_read_lock();
589 		i->buf.atomic++;
590 		tbl = rht_dereference_rcu(c->btree_cache.table.tbl,
591 					  &c->btree_cache.table);
592 		if (i->iter < tbl->size) {
593 			rht_for_each_entry_rcu(b, pos, tbl, i->iter, hash)
594 				bch2_cached_btree_node_to_text(&i->buf, c, b);
595 			i->iter++;
596 		} else {
597 			done = true;
598 		}
599 		--i->buf.atomic;
600 		rcu_read_unlock();
601 	} while (!done);
602 
603 	if (i->buf.allocation_failure)
604 		ret = -ENOMEM;
605 
606 	if (!ret)
607 		ret = flush_buf(i);
608 
609 	return ret ?: i->ret;
610 }
611 
612 static const struct file_operations cached_btree_nodes_ops = {
613 	.owner		= THIS_MODULE,
614 	.open		= bch2_dump_open,
615 	.release	= bch2_dump_release,
616 	.read		= bch2_cached_btree_nodes_read,
617 };
618 
619 #ifdef CONFIG_BCACHEFS_DEBUG_TRANSACTIONS
620 static ssize_t bch2_btree_transactions_read(struct file *file, char __user *buf,
621 					    size_t size, loff_t *ppos)
622 {
623 	struct dump_iter *i = file->private_data;
624 	struct bch_fs *c = i->c;
625 	struct btree_trans *trans;
626 	ssize_t ret = 0;
627 	u32 seq;
628 
629 	i->ubuf = buf;
630 	i->size	= size;
631 	i->ret	= 0;
632 restart:
633 	seqmutex_lock(&c->btree_trans_lock);
634 	list_for_each_entry(trans, &c->btree_trans_list, list) {
635 		if (trans->locking_wait.task->pid <= i->iter)
636 			continue;
637 
638 		closure_get(&trans->ref);
639 		seq = seqmutex_seq(&c->btree_trans_lock);
640 		seqmutex_unlock(&c->btree_trans_lock);
641 
642 		ret = flush_buf(i);
643 		if (ret) {
644 			closure_put(&trans->ref);
645 			goto unlocked;
646 		}
647 
648 		bch2_btree_trans_to_text(&i->buf, trans);
649 
650 		prt_printf(&i->buf, "backtrace:");
651 		prt_newline(&i->buf);
652 		printbuf_indent_add(&i->buf, 2);
653 		bch2_prt_task_backtrace(&i->buf, trans->locking_wait.task);
654 		printbuf_indent_sub(&i->buf, 2);
655 		prt_newline(&i->buf);
656 
657 		i->iter = trans->locking_wait.task->pid;
658 
659 		closure_put(&trans->ref);
660 
661 		if (!seqmutex_relock(&c->btree_trans_lock, seq))
662 			goto restart;
663 	}
664 	seqmutex_unlock(&c->btree_trans_lock);
665 unlocked:
666 	if (i->buf.allocation_failure)
667 		ret = -ENOMEM;
668 
669 	if (!ret)
670 		ret = flush_buf(i);
671 
672 	return ret ?: i->ret;
673 }
674 
675 static const struct file_operations btree_transactions_ops = {
676 	.owner		= THIS_MODULE,
677 	.open		= bch2_dump_open,
678 	.release	= bch2_dump_release,
679 	.read		= bch2_btree_transactions_read,
680 };
681 #endif /* CONFIG_BCACHEFS_DEBUG_TRANSACTIONS */
682 
683 static ssize_t bch2_journal_pins_read(struct file *file, char __user *buf,
684 				      size_t size, loff_t *ppos)
685 {
686 	struct dump_iter *i = file->private_data;
687 	struct bch_fs *c = i->c;
688 	bool done = false;
689 	int err;
690 
691 	i->ubuf = buf;
692 	i->size	= size;
693 	i->ret	= 0;
694 
695 	do {
696 		err = flush_buf(i);
697 		if (err)
698 			return err;
699 
700 		if (!i->size)
701 			break;
702 
703 		done = bch2_journal_seq_pins_to_text(&i->buf, &c->journal, &i->iter);
704 		i->iter++;
705 	} while (!done);
706 
707 	if (i->buf.allocation_failure)
708 		return -ENOMEM;
709 
710 	return i->ret;
711 }
712 
713 static const struct file_operations journal_pins_ops = {
714 	.owner		= THIS_MODULE,
715 	.open		= bch2_dump_open,
716 	.release	= bch2_dump_release,
717 	.read		= bch2_journal_pins_read,
718 };
719 
720 static int lock_held_stats_open(struct inode *inode, struct file *file)
721 {
722 	struct bch_fs *c = inode->i_private;
723 	struct dump_iter *i;
724 
725 	i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
726 
727 	if (!i)
728 		return -ENOMEM;
729 
730 	i->iter = 0;
731 	i->c    = c;
732 	i->buf  = PRINTBUF;
733 	file->private_data = i;
734 
735 	return 0;
736 }
737 
738 static int lock_held_stats_release(struct inode *inode, struct file *file)
739 {
740 	struct dump_iter *i = file->private_data;
741 
742 	printbuf_exit(&i->buf);
743 	kfree(i);
744 
745 	return 0;
746 }
747 
748 static ssize_t lock_held_stats_read(struct file *file, char __user *buf,
749 				      size_t size, loff_t *ppos)
750 {
751 	struct dump_iter        *i = file->private_data;
752 	struct bch_fs *c = i->c;
753 	int err;
754 
755 	i->ubuf = buf;
756 	i->size = size;
757 	i->ret  = 0;
758 
759 	while (1) {
760 		struct btree_transaction_stats *s = &c->btree_transaction_stats[i->iter];
761 
762 		err = flush_buf(i);
763 		if (err)
764 			return err;
765 
766 		if (!i->size)
767 			break;
768 
769 		if (i->iter == ARRAY_SIZE(bch2_btree_transaction_fns) ||
770 		    !bch2_btree_transaction_fns[i->iter])
771 			break;
772 
773 		prt_printf(&i->buf, "%s: ", bch2_btree_transaction_fns[i->iter]);
774 		prt_newline(&i->buf);
775 		printbuf_indent_add(&i->buf, 2);
776 
777 		mutex_lock(&s->lock);
778 
779 		prt_printf(&i->buf, "Max mem used: %u", s->max_mem);
780 		prt_newline(&i->buf);
781 
782 		if (IS_ENABLED(CONFIG_BCACHEFS_LOCK_TIME_STATS)) {
783 			prt_printf(&i->buf, "Lock hold times:");
784 			prt_newline(&i->buf);
785 
786 			printbuf_indent_add(&i->buf, 2);
787 			bch2_time_stats_to_text(&i->buf, &s->lock_hold_times);
788 			printbuf_indent_sub(&i->buf, 2);
789 		}
790 
791 		if (s->max_paths_text) {
792 			prt_printf(&i->buf, "Maximum allocated btree paths (%u):", s->nr_max_paths);
793 			prt_newline(&i->buf);
794 
795 			printbuf_indent_add(&i->buf, 2);
796 			prt_str_indented(&i->buf, s->max_paths_text);
797 			printbuf_indent_sub(&i->buf, 2);
798 		}
799 
800 		mutex_unlock(&s->lock);
801 
802 		printbuf_indent_sub(&i->buf, 2);
803 		prt_newline(&i->buf);
804 		i->iter++;
805 	}
806 
807 	if (i->buf.allocation_failure)
808 		return -ENOMEM;
809 
810 	return i->ret;
811 }
812 
813 static const struct file_operations lock_held_stats_op = {
814 	.owner = THIS_MODULE,
815 	.open = lock_held_stats_open,
816 	.release = lock_held_stats_release,
817 	.read = lock_held_stats_read,
818 };
819 
820 static ssize_t bch2_btree_deadlock_read(struct file *file, char __user *buf,
821 					    size_t size, loff_t *ppos)
822 {
823 	struct dump_iter *i = file->private_data;
824 	struct bch_fs *c = i->c;
825 	struct btree_trans *trans;
826 	ssize_t ret = 0;
827 	u32 seq;
828 
829 	i->ubuf = buf;
830 	i->size	= size;
831 	i->ret	= 0;
832 
833 	if (i->iter)
834 		goto out;
835 restart:
836 	seqmutex_lock(&c->btree_trans_lock);
837 	list_for_each_entry(trans, &c->btree_trans_list, list) {
838 		if (trans->locking_wait.task->pid <= i->iter)
839 			continue;
840 
841 		closure_get(&trans->ref);
842 		seq = seqmutex_seq(&c->btree_trans_lock);
843 		seqmutex_unlock(&c->btree_trans_lock);
844 
845 		ret = flush_buf(i);
846 		if (ret) {
847 			closure_put(&trans->ref);
848 			goto out;
849 		}
850 
851 		bch2_check_for_deadlock(trans, &i->buf);
852 
853 		i->iter = trans->locking_wait.task->pid;
854 
855 		closure_put(&trans->ref);
856 
857 		if (!seqmutex_relock(&c->btree_trans_lock, seq))
858 			goto restart;
859 	}
860 	seqmutex_unlock(&c->btree_trans_lock);
861 out:
862 	if (i->buf.allocation_failure)
863 		ret = -ENOMEM;
864 
865 	if (!ret)
866 		ret = flush_buf(i);
867 
868 	return ret ?: i->ret;
869 }
870 
871 static const struct file_operations btree_deadlock_ops = {
872 	.owner		= THIS_MODULE,
873 	.open		= bch2_dump_open,
874 	.release	= bch2_dump_release,
875 	.read		= bch2_btree_deadlock_read,
876 };
877 
878 void bch2_fs_debug_exit(struct bch_fs *c)
879 {
880 	if (!IS_ERR_OR_NULL(c->fs_debug_dir))
881 		debugfs_remove_recursive(c->fs_debug_dir);
882 }
883 
884 void bch2_fs_debug_init(struct bch_fs *c)
885 {
886 	struct btree_debug *bd;
887 	char name[100];
888 
889 	if (IS_ERR_OR_NULL(bch_debug))
890 		return;
891 
892 	snprintf(name, sizeof(name), "%pU", c->sb.user_uuid.b);
893 	c->fs_debug_dir = debugfs_create_dir(name, bch_debug);
894 	if (IS_ERR_OR_NULL(c->fs_debug_dir))
895 		return;
896 
897 	debugfs_create_file("cached_btree_nodes", 0400, c->fs_debug_dir,
898 			    c->btree_debug, &cached_btree_nodes_ops);
899 
900 #ifdef CONFIG_BCACHEFS_DEBUG_TRANSACTIONS
901 	debugfs_create_file("btree_transactions", 0400, c->fs_debug_dir,
902 			    c->btree_debug, &btree_transactions_ops);
903 #endif
904 
905 	debugfs_create_file("journal_pins", 0400, c->fs_debug_dir,
906 			    c->btree_debug, &journal_pins_ops);
907 
908 	debugfs_create_file("btree_transaction_stats", 0400, c->fs_debug_dir,
909 			    c, &lock_held_stats_op);
910 
911 	debugfs_create_file("btree_deadlock", 0400, c->fs_debug_dir,
912 			    c->btree_debug, &btree_deadlock_ops);
913 
914 	c->btree_debug_dir = debugfs_create_dir("btrees", c->fs_debug_dir);
915 	if (IS_ERR_OR_NULL(c->btree_debug_dir))
916 		return;
917 
918 	for (bd = c->btree_debug;
919 	     bd < c->btree_debug + ARRAY_SIZE(c->btree_debug);
920 	     bd++) {
921 		bd->id = bd - c->btree_debug;
922 		debugfs_create_file(bch2_btree_id_str(bd->id),
923 				    0400, c->btree_debug_dir, bd,
924 				    &btree_debug_ops);
925 
926 		snprintf(name, sizeof(name), "%s-formats",
927 			 bch2_btree_id_str(bd->id));
928 
929 		debugfs_create_file(name, 0400, c->btree_debug_dir, bd,
930 				    &btree_format_debug_ops);
931 
932 		snprintf(name, sizeof(name), "%s-bfloat-failed",
933 			 bch2_btree_id_str(bd->id));
934 
935 		debugfs_create_file(name, 0400, c->btree_debug_dir, bd,
936 				    &bfloat_failed_debug_ops);
937 	}
938 }
939 
940 #endif
941 
942 void bch2_debug_exit(void)
943 {
944 	if (!IS_ERR_OR_NULL(bch_debug))
945 		debugfs_remove_recursive(bch_debug);
946 }
947 
948 int __init bch2_debug_init(void)
949 {
950 	int ret = 0;
951 
952 	bch_debug = debugfs_create_dir("bcachefs", NULL);
953 	return ret;
954 }
955