xref: /linux/fs/bcachefs/debug.c (revision f96a974170b749e3a56844e25b31d46a7233b6f6)
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 "btree_update_interior.h"
17 #include "buckets.h"
18 #include "debug.h"
19 #include "error.h"
20 #include "extents.h"
21 #include "fsck.h"
22 #include "inode.h"
23 #include "super.h"
24 
25 #include <linux/console.h>
26 #include <linux/debugfs.h>
27 #include <linux/module.h>
28 #include <linux/random.h>
29 #include <linux/seq_file.h>
30 
31 static struct dentry *bch_debug;
32 
33 static bool bch2_btree_verify_replica(struct bch_fs *c, struct btree *b,
34 				      struct extent_ptr_decoded pick)
35 {
36 	struct btree *v = c->verify_data;
37 	struct btree_node *n_ondisk = c->verify_ondisk;
38 	struct btree_node *n_sorted = c->verify_data->data;
39 	struct bset *sorted, *inmemory = &b->data->keys;
40 	struct bio *bio;
41 	bool failed = false, saw_error = false;
42 
43 	struct bch_dev *ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
44 	if (!ca)
45 		return false;
46 
47 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
48 			       buf_pages(n_sorted, btree_buf_bytes(b)),
49 			       REQ_OP_READ|REQ_META,
50 			       GFP_NOFS,
51 			       &c->btree_bio);
52 	bio->bi_iter.bi_sector	= pick.ptr.offset;
53 	bch2_bio_map(bio, n_sorted, btree_buf_bytes(b));
54 
55 	submit_bio_wait(bio);
56 
57 	bio_put(bio);
58 	percpu_ref_put(&ca->io_ref);
59 
60 	memcpy(n_ondisk, n_sorted, btree_buf_bytes(b));
61 
62 	v->written = 0;
63 	if (bch2_btree_node_read_done(c, ca, v, false, &saw_error) || saw_error)
64 		return false;
65 
66 	n_sorted = c->verify_data->data;
67 	sorted = &n_sorted->keys;
68 
69 	if (inmemory->u64s != sorted->u64s ||
70 	    memcmp(inmemory->start,
71 		   sorted->start,
72 		   vstruct_end(inmemory) - (void *) inmemory->start)) {
73 		unsigned offset = 0, sectors;
74 		struct bset *i;
75 		unsigned j;
76 
77 		console_lock();
78 
79 		printk(KERN_ERR "*** in memory:\n");
80 		bch2_dump_bset(c, b, inmemory, 0);
81 
82 		printk(KERN_ERR "*** read back in:\n");
83 		bch2_dump_bset(c, v, sorted, 0);
84 
85 		while (offset < v->written) {
86 			if (!offset) {
87 				i = &n_ondisk->keys;
88 				sectors = vstruct_blocks(n_ondisk, c->block_bits) <<
89 					c->block_bits;
90 			} else {
91 				struct btree_node_entry *bne =
92 					(void *) n_ondisk + (offset << 9);
93 				i = &bne->keys;
94 
95 				sectors = vstruct_blocks(bne, c->block_bits) <<
96 					c->block_bits;
97 			}
98 
99 			printk(KERN_ERR "*** on disk block %u:\n", offset);
100 			bch2_dump_bset(c, b, i, offset);
101 
102 			offset += sectors;
103 		}
104 
105 		for (j = 0; j < le16_to_cpu(inmemory->u64s); j++)
106 			if (inmemory->_data[j] != sorted->_data[j])
107 				break;
108 
109 		console_unlock();
110 		bch_err(c, "verify failed at key %u", j);
111 
112 		failed = true;
113 	}
114 
115 	if (v->written != b->written) {
116 		bch_err(c, "written wrong: expected %u, got %u",
117 			b->written, v->written);
118 		failed = true;
119 	}
120 
121 	return failed;
122 }
123 
124 void __bch2_btree_verify(struct bch_fs *c, struct btree *b)
125 {
126 	struct bkey_ptrs_c ptrs;
127 	struct extent_ptr_decoded p;
128 	const union bch_extent_entry *entry;
129 	struct btree *v;
130 	struct bset *inmemory = &b->data->keys;
131 	struct bkey_packed *k;
132 	bool failed = false;
133 
134 	if (c->opts.nochanges)
135 		return;
136 
137 	bch2_btree_node_io_lock(b);
138 	mutex_lock(&c->verify_lock);
139 
140 	if (!c->verify_ondisk) {
141 		c->verify_ondisk = kvmalloc(btree_buf_bytes(b), GFP_KERNEL);
142 		if (!c->verify_ondisk)
143 			goto out;
144 	}
145 
146 	if (!c->verify_data) {
147 		c->verify_data = __bch2_btree_node_mem_alloc(c);
148 		if (!c->verify_data)
149 			goto out;
150 
151 		list_del_init(&c->verify_data->list);
152 	}
153 
154 	BUG_ON(b->nsets != 1);
155 
156 	for (k = inmemory->start; k != vstruct_last(inmemory); k = bkey_p_next(k))
157 		if (k->type == KEY_TYPE_btree_ptr_v2)
158 			((struct bch_btree_ptr_v2 *) bkeyp_val(&b->format, k))->mem_ptr = 0;
159 
160 	v = c->verify_data;
161 	bkey_copy(&v->key, &b->key);
162 	v->c.level	= b->c.level;
163 	v->c.btree_id	= b->c.btree_id;
164 	bch2_btree_keys_init(v);
165 
166 	ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(&b->key));
167 	bkey_for_each_ptr_decode(&b->key.k, ptrs, p, entry)
168 		failed |= bch2_btree_verify_replica(c, b, p);
169 
170 	if (failed) {
171 		struct printbuf buf = PRINTBUF;
172 
173 		bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&b->key));
174 		bch2_fs_fatal_error(c, ": btree node verify failed for: %s\n", buf.buf);
175 		printbuf_exit(&buf);
176 	}
177 out:
178 	mutex_unlock(&c->verify_lock);
179 	bch2_btree_node_io_unlock(b);
180 }
181 
182 void bch2_btree_node_ondisk_to_text(struct printbuf *out, struct bch_fs *c,
183 				    const struct btree *b)
184 {
185 	struct btree_node *n_ondisk = NULL;
186 	struct extent_ptr_decoded pick;
187 	struct bch_dev *ca;
188 	struct bio *bio = NULL;
189 	unsigned offset = 0;
190 	int ret;
191 
192 	if (bch2_bkey_pick_read_device(c, bkey_i_to_s_c(&b->key), NULL, &pick) <= 0) {
193 		prt_printf(out, "error getting device to read from: invalid device\n");
194 		return;
195 	}
196 
197 	ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
198 	if (!ca) {
199 		prt_printf(out, "error getting device to read from: not online\n");
200 		return;
201 	}
202 
203 	n_ondisk = kvmalloc(btree_buf_bytes(b), GFP_KERNEL);
204 	if (!n_ondisk) {
205 		prt_printf(out, "memory allocation failure\n");
206 		goto out;
207 	}
208 
209 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
210 			       buf_pages(n_ondisk, btree_buf_bytes(b)),
211 			       REQ_OP_READ|REQ_META,
212 			       GFP_NOFS,
213 			       &c->btree_bio);
214 	bio->bi_iter.bi_sector	= pick.ptr.offset;
215 	bch2_bio_map(bio, n_ondisk, btree_buf_bytes(b));
216 
217 	ret = submit_bio_wait(bio);
218 	if (ret) {
219 		prt_printf(out, "IO error reading btree node: %s\n", bch2_err_str(ret));
220 		goto out;
221 	}
222 
223 	while (offset < btree_sectors(c)) {
224 		struct bset *i;
225 		struct nonce nonce;
226 		struct bch_csum csum;
227 		struct bkey_packed *k;
228 		unsigned sectors;
229 
230 		if (!offset) {
231 			i = &n_ondisk->keys;
232 
233 			if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
234 				prt_printf(out, "unknown checksum type at offset %u: %llu\n",
235 					   offset, BSET_CSUM_TYPE(i));
236 				goto out;
237 			}
238 
239 			nonce = btree_nonce(i, offset << 9);
240 			csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, n_ondisk);
241 
242 			if (bch2_crc_cmp(csum, n_ondisk->csum)) {
243 				prt_printf(out, "invalid checksum\n");
244 				goto out;
245 			}
246 
247 			bset_encrypt(c, i, offset << 9);
248 
249 			sectors = vstruct_sectors(n_ondisk, c->block_bits);
250 		} else {
251 			struct btree_node_entry *bne = (void *) n_ondisk + (offset << 9);
252 
253 			i = &bne->keys;
254 
255 			if (i->seq != n_ondisk->keys.seq)
256 				break;
257 
258 			if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
259 				prt_printf(out, "unknown checksum type at offset %u: %llu\n",
260 					   offset, BSET_CSUM_TYPE(i));
261 				goto out;
262 			}
263 
264 			nonce = btree_nonce(i, offset << 9);
265 			csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, bne);
266 
267 			if (bch2_crc_cmp(csum, bne->csum)) {
268 				prt_printf(out, "invalid checksum");
269 				goto out;
270 			}
271 
272 			bset_encrypt(c, i, offset << 9);
273 
274 			sectors = vstruct_sectors(bne, c->block_bits);
275 		}
276 
277 		prt_printf(out, "  offset %u version %u, journal seq %llu\n",
278 			   offset,
279 			   le16_to_cpu(i->version),
280 			   le64_to_cpu(i->journal_seq));
281 		offset += sectors;
282 
283 		printbuf_indent_add(out, 4);
284 
285 		for (k = i->start; k != vstruct_last(i); k = bkey_p_next(k)) {
286 			struct bkey u;
287 
288 			bch2_bkey_val_to_text(out, c, bkey_disassemble(b, k, &u));
289 			prt_newline(out);
290 		}
291 
292 		printbuf_indent_sub(out, 4);
293 	}
294 out:
295 	if (bio)
296 		bio_put(bio);
297 	kvfree(n_ondisk);
298 	percpu_ref_put(&ca->io_ref);
299 }
300 
301 #ifdef CONFIG_DEBUG_FS
302 
303 /* XXX: bch_fs refcounting */
304 
305 struct dump_iter {
306 	struct bch_fs		*c;
307 	enum btree_id		id;
308 	struct bpos		from;
309 	struct bpos		prev_node;
310 	u64			iter;
311 
312 	struct printbuf		buf;
313 
314 	char __user		*ubuf;	/* destination user buffer */
315 	size_t			size;	/* size of requested read */
316 	ssize_t			ret;	/* bytes read so far */
317 };
318 
319 static ssize_t flush_buf(struct dump_iter *i)
320 {
321 	if (i->buf.pos) {
322 		size_t bytes = min_t(size_t, i->buf.pos, i->size);
323 		int copied = bytes - copy_to_user(i->ubuf, i->buf.buf, bytes);
324 
325 		i->ret	 += copied;
326 		i->ubuf	 += copied;
327 		i->size	 -= copied;
328 		i->buf.pos -= copied;
329 		memmove(i->buf.buf, i->buf.buf + copied, i->buf.pos);
330 
331 		if (copied != bytes)
332 			return -EFAULT;
333 	}
334 
335 	return i->size ? 0 : i->ret;
336 }
337 
338 static int bch2_dump_open(struct inode *inode, struct file *file)
339 {
340 	struct btree_debug *bd = inode->i_private;
341 	struct dump_iter *i;
342 
343 	i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
344 	if (!i)
345 		return -ENOMEM;
346 
347 	file->private_data = i;
348 	i->from = POS_MIN;
349 	i->iter	= 0;
350 	i->c	= container_of(bd, struct bch_fs, btree_debug[bd->id]);
351 	i->id	= bd->id;
352 	i->buf	= PRINTBUF;
353 
354 	return 0;
355 }
356 
357 static int bch2_dump_release(struct inode *inode, struct file *file)
358 {
359 	struct dump_iter *i = file->private_data;
360 
361 	printbuf_exit(&i->buf);
362 	kfree(i);
363 	return 0;
364 }
365 
366 static ssize_t bch2_read_btree(struct file *file, char __user *buf,
367 			       size_t size, loff_t *ppos)
368 {
369 	struct dump_iter *i = file->private_data;
370 
371 	i->ubuf = buf;
372 	i->size	= size;
373 	i->ret	= 0;
374 
375 	return flush_buf(i) ?:
376 		bch2_trans_run(i->c,
377 			for_each_btree_key(trans, iter, i->id, i->from,
378 					   BTREE_ITER_prefetch|
379 					   BTREE_ITER_all_snapshots, k, ({
380 				bch2_bkey_val_to_text(&i->buf, i->c, k);
381 				prt_newline(&i->buf);
382 				bch2_trans_unlock(trans);
383 				i->from = bpos_successor(iter.pos);
384 				flush_buf(i);
385 			}))) ?:
386 		i->ret;
387 }
388 
389 static const struct file_operations btree_debug_ops = {
390 	.owner		= THIS_MODULE,
391 	.open		= bch2_dump_open,
392 	.release	= bch2_dump_release,
393 	.read		= bch2_read_btree,
394 };
395 
396 static ssize_t bch2_read_btree_formats(struct file *file, char __user *buf,
397 				       size_t size, loff_t *ppos)
398 {
399 	struct dump_iter *i = file->private_data;
400 
401 	i->ubuf = buf;
402 	i->size	= size;
403 	i->ret	= 0;
404 
405 	ssize_t ret = flush_buf(i);
406 	if (ret)
407 		return ret;
408 
409 	if (bpos_eq(SPOS_MAX, i->from))
410 		return i->ret;
411 
412 	return bch2_trans_run(i->c,
413 		for_each_btree_node(trans, iter, i->id, i->from, 0, b, ({
414 			bch2_btree_node_to_text(&i->buf, i->c, b);
415 			i->from = !bpos_eq(SPOS_MAX, b->key.k.p)
416 				? bpos_successor(b->key.k.p)
417 				: b->key.k.p;
418 
419 			drop_locks_do(trans, flush_buf(i));
420 		}))) ?: i->ret;
421 }
422 
423 static const struct file_operations btree_format_debug_ops = {
424 	.owner		= THIS_MODULE,
425 	.open		= bch2_dump_open,
426 	.release	= bch2_dump_release,
427 	.read		= bch2_read_btree_formats,
428 };
429 
430 static ssize_t bch2_read_bfloat_failed(struct file *file, char __user *buf,
431 				       size_t size, loff_t *ppos)
432 {
433 	struct dump_iter *i = file->private_data;
434 
435 	i->ubuf = buf;
436 	i->size	= size;
437 	i->ret	= 0;
438 
439 	return flush_buf(i) ?:
440 		bch2_trans_run(i->c,
441 			for_each_btree_key(trans, iter, i->id, i->from,
442 					   BTREE_ITER_prefetch|
443 					   BTREE_ITER_all_snapshots, k, ({
444 				struct btree_path_level *l =
445 					&btree_iter_path(trans, &iter)->l[0];
446 				struct bkey_packed *_k =
447 					bch2_btree_node_iter_peek(&l->iter, l->b);
448 
449 				if (bpos_gt(l->b->key.k.p, i->prev_node)) {
450 					bch2_btree_node_to_text(&i->buf, i->c, l->b);
451 					i->prev_node = l->b->key.k.p;
452 				}
453 
454 				bch2_bfloat_to_text(&i->buf, l->b, _k);
455 				bch2_trans_unlock(trans);
456 				i->from = bpos_successor(iter.pos);
457 				flush_buf(i);
458 			}))) ?:
459 		i->ret;
460 }
461 
462 static const struct file_operations bfloat_failed_debug_ops = {
463 	.owner		= THIS_MODULE,
464 	.open		= bch2_dump_open,
465 	.release	= bch2_dump_release,
466 	.read		= bch2_read_bfloat_failed,
467 };
468 
469 static void bch2_cached_btree_node_to_text(struct printbuf *out, struct bch_fs *c,
470 					   struct btree *b)
471 {
472 	if (!out->nr_tabstops)
473 		printbuf_tabstop_push(out, 32);
474 
475 	prt_printf(out, "%px ", b);
476 	bch2_btree_id_level_to_text(out, b->c.btree_id, b->c.level);
477 	prt_printf(out, "\n");
478 
479 	printbuf_indent_add(out, 2);
480 
481 	bch2_bkey_val_to_text(out, c, bkey_i_to_s_c(&b->key));
482 	prt_newline(out);
483 
484 	prt_printf(out, "flags:\t");
485 	prt_bitflags(out, bch2_btree_node_flags, b->flags);
486 	prt_newline(out);
487 
488 	prt_printf(out, "pcpu read locks:\t%u\n",	b->c.lock.readers != NULL);
489 	prt_printf(out, "written:\t%u\n",		b->written);
490 	prt_printf(out, "writes blocked:\t%u\n",	!list_empty_careful(&b->write_blocked));
491 	prt_printf(out, "will make reachable:\t%lx\n",	b->will_make_reachable);
492 
493 	prt_printf(out, "journal pin %px:\t%llu\n",
494 		   &b->writes[0].journal, b->writes[0].journal.seq);
495 	prt_printf(out, "journal pin %px:\t%llu\n",
496 		   &b->writes[1].journal, b->writes[1].journal.seq);
497 
498 	printbuf_indent_sub(out, 2);
499 }
500 
501 static ssize_t bch2_cached_btree_nodes_read(struct file *file, char __user *buf,
502 					    size_t size, loff_t *ppos)
503 {
504 	struct dump_iter *i = file->private_data;
505 	struct bch_fs *c = i->c;
506 	bool done = false;
507 	ssize_t ret = 0;
508 
509 	i->ubuf = buf;
510 	i->size	= size;
511 	i->ret	= 0;
512 
513 	do {
514 		struct bucket_table *tbl;
515 		struct rhash_head *pos;
516 		struct btree *b;
517 
518 		ret = flush_buf(i);
519 		if (ret)
520 			return ret;
521 
522 		rcu_read_lock();
523 		i->buf.atomic++;
524 		tbl = rht_dereference_rcu(c->btree_cache.table.tbl,
525 					  &c->btree_cache.table);
526 		if (i->iter < tbl->size) {
527 			rht_for_each_entry_rcu(b, pos, tbl, i->iter, hash)
528 				bch2_cached_btree_node_to_text(&i->buf, c, b);
529 			i->iter++;
530 		} else {
531 			done = true;
532 		}
533 		--i->buf.atomic;
534 		rcu_read_unlock();
535 	} while (!done);
536 
537 	if (i->buf.allocation_failure)
538 		ret = -ENOMEM;
539 
540 	if (!ret)
541 		ret = flush_buf(i);
542 
543 	return ret ?: i->ret;
544 }
545 
546 static const struct file_operations cached_btree_nodes_ops = {
547 	.owner		= THIS_MODULE,
548 	.open		= bch2_dump_open,
549 	.release	= bch2_dump_release,
550 	.read		= bch2_cached_btree_nodes_read,
551 };
552 
553 typedef int (*list_cmp_fn)(const struct list_head *l, const struct list_head *r);
554 
555 static void list_sort(struct list_head *head, list_cmp_fn cmp)
556 {
557 	struct list_head *pos;
558 
559 	list_for_each(pos, head)
560 		while (!list_is_last(pos, head) &&
561 		       cmp(pos, pos->next) > 0) {
562 			struct list_head *pos2, *next = pos->next;
563 
564 			list_del(next);
565 			list_for_each(pos2, head)
566 				if (cmp(next, pos2) < 0)
567 					goto pos_found;
568 			BUG();
569 pos_found:
570 			list_add_tail(next, pos2);
571 		}
572 }
573 
574 static int list_ptr_order_cmp(const struct list_head *l, const struct list_head *r)
575 {
576 	return cmp_int(l, r);
577 }
578 
579 static ssize_t bch2_btree_transactions_read(struct file *file, char __user *buf,
580 					    size_t size, loff_t *ppos)
581 {
582 	struct dump_iter *i = file->private_data;
583 	struct bch_fs *c = i->c;
584 	struct btree_trans *trans;
585 	ssize_t ret = 0;
586 
587 	i->ubuf = buf;
588 	i->size	= size;
589 	i->ret	= 0;
590 restart:
591 	seqmutex_lock(&c->btree_trans_lock);
592 	list_sort(&c->btree_trans_list, list_ptr_order_cmp);
593 
594 	list_for_each_entry(trans, &c->btree_trans_list, list) {
595 		if ((ulong) trans <= i->iter)
596 			continue;
597 
598 		i->iter = (ulong) trans;
599 
600 		if (!closure_get_not_zero(&trans->ref))
601 			continue;
602 
603 		u32 seq = seqmutex_unlock(&c->btree_trans_lock);
604 
605 		bch2_btree_trans_to_text(&i->buf, trans);
606 
607 		prt_printf(&i->buf, "backtrace:\n");
608 		printbuf_indent_add(&i->buf, 2);
609 		bch2_prt_task_backtrace(&i->buf, trans->locking_wait.task, 0, GFP_KERNEL);
610 		printbuf_indent_sub(&i->buf, 2);
611 		prt_newline(&i->buf);
612 
613 		closure_put(&trans->ref);
614 
615 		ret = flush_buf(i);
616 		if (ret)
617 			goto unlocked;
618 
619 		if (!seqmutex_relock(&c->btree_trans_lock, seq))
620 			goto restart;
621 	}
622 	seqmutex_unlock(&c->btree_trans_lock);
623 unlocked:
624 	if (i->buf.allocation_failure)
625 		ret = -ENOMEM;
626 
627 	if (!ret)
628 		ret = flush_buf(i);
629 
630 	return ret ?: i->ret;
631 }
632 
633 static const struct file_operations btree_transactions_ops = {
634 	.owner		= THIS_MODULE,
635 	.open		= bch2_dump_open,
636 	.release	= bch2_dump_release,
637 	.read		= bch2_btree_transactions_read,
638 };
639 
640 static ssize_t bch2_journal_pins_read(struct file *file, char __user *buf,
641 				      size_t size, loff_t *ppos)
642 {
643 	struct dump_iter *i = file->private_data;
644 	struct bch_fs *c = i->c;
645 	bool done = false;
646 	int err;
647 
648 	i->ubuf = buf;
649 	i->size	= size;
650 	i->ret	= 0;
651 
652 	while (1) {
653 		err = flush_buf(i);
654 		if (err)
655 			return err;
656 
657 		if (!i->size)
658 			break;
659 
660 		if (done)
661 			break;
662 
663 		done = bch2_journal_seq_pins_to_text(&i->buf, &c->journal, &i->iter);
664 		i->iter++;
665 	}
666 
667 	if (i->buf.allocation_failure)
668 		return -ENOMEM;
669 
670 	return i->ret;
671 }
672 
673 static const struct file_operations journal_pins_ops = {
674 	.owner		= THIS_MODULE,
675 	.open		= bch2_dump_open,
676 	.release	= bch2_dump_release,
677 	.read		= bch2_journal_pins_read,
678 };
679 
680 static ssize_t bch2_btree_updates_read(struct file *file, char __user *buf,
681 				       size_t size, loff_t *ppos)
682 {
683 	struct dump_iter *i = file->private_data;
684 	struct bch_fs *c = i->c;
685 	int err;
686 
687 	i->ubuf = buf;
688 	i->size	= size;
689 	i->ret	= 0;
690 
691 	if (!i->iter) {
692 		bch2_btree_updates_to_text(&i->buf, c);
693 		i->iter++;
694 	}
695 
696 	err = flush_buf(i);
697 	if (err)
698 		return err;
699 
700 	if (i->buf.allocation_failure)
701 		return -ENOMEM;
702 
703 	return i->ret;
704 }
705 
706 static const struct file_operations btree_updates_ops = {
707 	.owner		= THIS_MODULE,
708 	.open		= bch2_dump_open,
709 	.release	= bch2_dump_release,
710 	.read		= bch2_btree_updates_read,
711 };
712 
713 static int btree_transaction_stats_open(struct inode *inode, struct file *file)
714 {
715 	struct bch_fs *c = inode->i_private;
716 	struct dump_iter *i;
717 
718 	i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
719 	if (!i)
720 		return -ENOMEM;
721 
722 	i->iter = 1;
723 	i->c    = c;
724 	i->buf  = PRINTBUF;
725 	file->private_data = i;
726 
727 	return 0;
728 }
729 
730 static int btree_transaction_stats_release(struct inode *inode, struct file *file)
731 {
732 	struct dump_iter *i = file->private_data;
733 
734 	printbuf_exit(&i->buf);
735 	kfree(i);
736 
737 	return 0;
738 }
739 
740 static ssize_t btree_transaction_stats_read(struct file *file, char __user *buf,
741 					    size_t size, loff_t *ppos)
742 {
743 	struct dump_iter        *i = file->private_data;
744 	struct bch_fs *c = i->c;
745 	int err;
746 
747 	i->ubuf = buf;
748 	i->size = size;
749 	i->ret  = 0;
750 
751 	while (1) {
752 		struct btree_transaction_stats *s = &c->btree_transaction_stats[i->iter];
753 
754 		err = flush_buf(i);
755 		if (err)
756 			return err;
757 
758 		if (!i->size)
759 			break;
760 
761 		if (i->iter == ARRAY_SIZE(bch2_btree_transaction_fns) ||
762 		    !bch2_btree_transaction_fns[i->iter])
763 			break;
764 
765 		prt_printf(&i->buf, "%s:\n", bch2_btree_transaction_fns[i->iter]);
766 		printbuf_indent_add(&i->buf, 2);
767 
768 		mutex_lock(&s->lock);
769 
770 		prt_printf(&i->buf, "Max mem used: %u\n", s->max_mem);
771 		prt_printf(&i->buf, "Transaction duration:\n");
772 
773 		printbuf_indent_add(&i->buf, 2);
774 		bch2_time_stats_to_text(&i->buf, &s->duration);
775 		printbuf_indent_sub(&i->buf, 2);
776 
777 		if (IS_ENABLED(CONFIG_BCACHEFS_LOCK_TIME_STATS)) {
778 			prt_printf(&i->buf, "Lock hold times:\n");
779 
780 			printbuf_indent_add(&i->buf, 2);
781 			bch2_time_stats_to_text(&i->buf, &s->lock_hold_times);
782 			printbuf_indent_sub(&i->buf, 2);
783 		}
784 
785 		if (s->max_paths_text) {
786 			prt_printf(&i->buf, "Maximum allocated btree paths (%u):\n", s->nr_max_paths);
787 
788 			printbuf_indent_add(&i->buf, 2);
789 			prt_str_indented(&i->buf, s->max_paths_text);
790 			printbuf_indent_sub(&i->buf, 2);
791 		}
792 
793 		mutex_unlock(&s->lock);
794 
795 		printbuf_indent_sub(&i->buf, 2);
796 		prt_newline(&i->buf);
797 		i->iter++;
798 	}
799 
800 	if (i->buf.allocation_failure)
801 		return -ENOMEM;
802 
803 	return i->ret;
804 }
805 
806 static const struct file_operations btree_transaction_stats_op = {
807 	.owner		= THIS_MODULE,
808 	.open		= btree_transaction_stats_open,
809 	.release	= btree_transaction_stats_release,
810 	.read		= btree_transaction_stats_read,
811 };
812 
813 /* walk btree transactions until we find a deadlock and print it */
814 static void btree_deadlock_to_text(struct printbuf *out, struct bch_fs *c)
815 {
816 	struct btree_trans *trans;
817 	ulong iter = 0;
818 restart:
819 	seqmutex_lock(&c->btree_trans_lock);
820 	list_sort(&c->btree_trans_list, list_ptr_order_cmp);
821 
822 	list_for_each_entry(trans, &c->btree_trans_list, list) {
823 		if ((ulong) trans <= iter)
824 			continue;
825 
826 		iter = (ulong) trans;
827 
828 		if (!closure_get_not_zero(&trans->ref))
829 			continue;
830 
831 		u32 seq = seqmutex_unlock(&c->btree_trans_lock);
832 
833 		bool found = bch2_check_for_deadlock(trans, out) != 0;
834 
835 		closure_put(&trans->ref);
836 
837 		if (found)
838 			return;
839 
840 		if (!seqmutex_relock(&c->btree_trans_lock, seq))
841 			goto restart;
842 	}
843 	seqmutex_unlock(&c->btree_trans_lock);
844 }
845 
846 static ssize_t bch2_btree_deadlock_read(struct file *file, char __user *buf,
847 					    size_t size, loff_t *ppos)
848 {
849 	struct dump_iter *i = file->private_data;
850 	struct bch_fs *c = i->c;
851 	ssize_t ret = 0;
852 
853 	i->ubuf = buf;
854 	i->size	= size;
855 	i->ret	= 0;
856 
857 	if (!i->iter) {
858 		btree_deadlock_to_text(&i->buf, c);
859 		i->iter++;
860 	}
861 
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 static void bch2_fs_debug_btree_init(struct bch_fs *c, struct btree_debug *bd)
885 {
886 	struct dentry *d;
887 
888 	d = debugfs_create_dir(bch2_btree_id_str(bd->id), c->btree_debug_dir);
889 
890 	debugfs_create_file("keys", 0400, d, bd, &btree_debug_ops);
891 
892 	debugfs_create_file("formats", 0400, d, bd, &btree_format_debug_ops);
893 
894 	debugfs_create_file("bfloat-failed", 0400, d, bd,
895 			    &bfloat_failed_debug_ops);
896 }
897 
898 void bch2_fs_debug_init(struct bch_fs *c)
899 {
900 	struct btree_debug *bd;
901 	char name[100];
902 
903 	if (IS_ERR_OR_NULL(bch_debug))
904 		return;
905 
906 	snprintf(name, sizeof(name), "%pU", c->sb.user_uuid.b);
907 	c->fs_debug_dir = debugfs_create_dir(name, bch_debug);
908 	if (IS_ERR_OR_NULL(c->fs_debug_dir))
909 		return;
910 
911 	debugfs_create_file("cached_btree_nodes", 0400, c->fs_debug_dir,
912 			    c->btree_debug, &cached_btree_nodes_ops);
913 
914 	debugfs_create_file("btree_transactions", 0400, c->fs_debug_dir,
915 			    c->btree_debug, &btree_transactions_ops);
916 
917 	debugfs_create_file("journal_pins", 0400, c->fs_debug_dir,
918 			    c->btree_debug, &journal_pins_ops);
919 
920 	debugfs_create_file("btree_updates", 0400, c->fs_debug_dir,
921 			    c->btree_debug, &btree_updates_ops);
922 
923 	debugfs_create_file("btree_transaction_stats", 0400, c->fs_debug_dir,
924 			    c, &btree_transaction_stats_op);
925 
926 	debugfs_create_file("btree_deadlock", 0400, c->fs_debug_dir,
927 			    c->btree_debug, &btree_deadlock_ops);
928 
929 	c->btree_debug_dir = debugfs_create_dir("btrees", c->fs_debug_dir);
930 	if (IS_ERR_OR_NULL(c->btree_debug_dir))
931 		return;
932 
933 	for (bd = c->btree_debug;
934 	     bd < c->btree_debug + ARRAY_SIZE(c->btree_debug);
935 	     bd++) {
936 		bd->id = bd - c->btree_debug;
937 		bch2_fs_debug_btree_init(c, bd);
938 	}
939 }
940 
941 #endif
942 
943 void bch2_debug_exit(void)
944 {
945 	if (!IS_ERR_OR_NULL(bch_debug))
946 		debugfs_remove_recursive(bch_debug);
947 }
948 
949 int __init bch2_debug_init(void)
950 {
951 	bch_debug = debugfs_create_dir("bcachefs", NULL);
952 	return 0;
953 }
954