xref: /linux/fs/bcachefs/debug.c (revision ff0905bbf991f4337b5ebc19c0d43525ebb0d96b)
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 "alloc_foreground.h"
11 #include "async_objs.h"
12 #include "bkey_methods.h"
13 #include "btree_cache.h"
14 #include "btree_io.h"
15 #include "btree_iter.h"
16 #include "btree_locking.h"
17 #include "btree_update.h"
18 #include "btree_update_interior.h"
19 #include "buckets.h"
20 #include "data_update.h"
21 #include "debug.h"
22 #include "error.h"
23 #include "extents.h"
24 #include "fsck.h"
25 #include "inode.h"
26 #include "journal_reclaim.h"
27 #include "super.h"
28 
29 #include <linux/console.h>
30 #include <linux/debugfs.h>
31 #include <linux/module.h>
32 #include <linux/random.h>
33 #include <linux/seq_file.h>
34 
35 static struct dentry *bch_debug;
36 
bch2_btree_verify_replica(struct bch_fs * c,struct btree * b,struct extent_ptr_decoded pick)37 static bool bch2_btree_verify_replica(struct bch_fs *c, struct btree *b,
38 				      struct extent_ptr_decoded pick)
39 {
40 	struct btree *v = c->verify_data;
41 	struct btree_node *n_ondisk = c->verify_ondisk;
42 	struct btree_node *n_sorted = c->verify_data->data;
43 	struct bset *sorted, *inmemory = &b->data->keys;
44 	struct bio *bio;
45 	bool failed = false;
46 
47 	struct bch_dev *ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ,
48 				BCH_DEV_READ_REF_btree_verify_replicas);
49 	if (!ca)
50 		return false;
51 
52 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
53 			       buf_pages(n_sorted, btree_buf_bytes(b)),
54 			       REQ_OP_READ|REQ_META,
55 			       GFP_NOFS,
56 			       &c->btree_bio);
57 	bio->bi_iter.bi_sector	= pick.ptr.offset;
58 	bch2_bio_map(bio, n_sorted, btree_buf_bytes(b));
59 
60 	submit_bio_wait(bio);
61 
62 	bio_put(bio);
63 	enumerated_ref_put(&ca->io_ref[READ],
64 			   BCH_DEV_READ_REF_btree_verify_replicas);
65 
66 	memcpy(n_ondisk, n_sorted, btree_buf_bytes(b));
67 
68 	v->written = 0;
69 	if (bch2_btree_node_read_done(c, ca, v, NULL, NULL))
70 		return false;
71 
72 	n_sorted = c->verify_data->data;
73 	sorted = &n_sorted->keys;
74 
75 	if (inmemory->u64s != sorted->u64s ||
76 	    memcmp(inmemory->start,
77 		   sorted->start,
78 		   vstruct_end(inmemory) - (void *) inmemory->start)) {
79 		unsigned offset = 0, sectors;
80 		struct bset *i;
81 		unsigned j;
82 
83 		console_lock();
84 
85 		printk(KERN_ERR "*** in memory:\n");
86 		bch2_dump_bset(c, b, inmemory, 0);
87 
88 		printk(KERN_ERR "*** read back in:\n");
89 		bch2_dump_bset(c, v, sorted, 0);
90 
91 		while (offset < v->written) {
92 			if (!offset) {
93 				i = &n_ondisk->keys;
94 				sectors = vstruct_blocks(n_ondisk, c->block_bits) <<
95 					c->block_bits;
96 			} else {
97 				struct btree_node_entry *bne =
98 					(void *) n_ondisk + (offset << 9);
99 				i = &bne->keys;
100 
101 				sectors = vstruct_blocks(bne, c->block_bits) <<
102 					c->block_bits;
103 			}
104 
105 			printk(KERN_ERR "*** on disk block %u:\n", offset);
106 			bch2_dump_bset(c, b, i, offset);
107 
108 			offset += sectors;
109 		}
110 
111 		for (j = 0; j < le16_to_cpu(inmemory->u64s); j++)
112 			if (inmemory->_data[j] != sorted->_data[j])
113 				break;
114 
115 		console_unlock();
116 		bch_err(c, "verify failed at key %u", j);
117 
118 		failed = true;
119 	}
120 
121 	if (v->written != b->written) {
122 		bch_err(c, "written wrong: expected %u, got %u",
123 			b->written, v->written);
124 		failed = true;
125 	}
126 
127 	return failed;
128 }
129 
__bch2_btree_verify(struct bch_fs * c,struct btree * b)130 void __bch2_btree_verify(struct bch_fs *c, struct btree *b)
131 {
132 	struct bkey_ptrs_c ptrs;
133 	struct extent_ptr_decoded p;
134 	const union bch_extent_entry *entry;
135 	struct btree *v;
136 	struct bset *inmemory = &b->data->keys;
137 	struct bkey_packed *k;
138 	bool failed = false;
139 
140 	if (c->opts.nochanges)
141 		return;
142 
143 	bch2_btree_node_io_lock(b);
144 	mutex_lock(&c->verify_lock);
145 
146 	if (!c->verify_ondisk) {
147 		c->verify_ondisk = kvmalloc(btree_buf_bytes(b), GFP_KERNEL);
148 		if (!c->verify_ondisk)
149 			goto out;
150 	}
151 
152 	if (!c->verify_data) {
153 		c->verify_data = __bch2_btree_node_mem_alloc(c);
154 		if (!c->verify_data)
155 			goto out;
156 
157 		list_del_init(&c->verify_data->list);
158 	}
159 
160 	BUG_ON(b->nsets != 1);
161 
162 	for (k = inmemory->start; k != vstruct_last(inmemory); k = bkey_p_next(k))
163 		if (k->type == KEY_TYPE_btree_ptr_v2)
164 			((struct bch_btree_ptr_v2 *) bkeyp_val(&b->format, k))->mem_ptr = 0;
165 
166 	v = c->verify_data;
167 	bkey_copy(&v->key, &b->key);
168 	v->c.level	= b->c.level;
169 	v->c.btree_id	= b->c.btree_id;
170 	bch2_btree_keys_init(v);
171 
172 	ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(&b->key));
173 	bkey_for_each_ptr_decode(&b->key.k, ptrs, p, entry)
174 		failed |= bch2_btree_verify_replica(c, b, p);
175 
176 	if (failed) {
177 		struct printbuf buf = PRINTBUF;
178 
179 		bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&b->key));
180 		bch2_fs_fatal_error(c, ": btree node verify failed for: %s\n", buf.buf);
181 		printbuf_exit(&buf);
182 	}
183 out:
184 	mutex_unlock(&c->verify_lock);
185 	bch2_btree_node_io_unlock(b);
186 }
187 
bch2_btree_node_ondisk_to_text(struct printbuf * out,struct bch_fs * c,const struct btree * b)188 void bch2_btree_node_ondisk_to_text(struct printbuf *out, struct bch_fs *c,
189 				    const struct btree *b)
190 {
191 	struct btree_node *n_ondisk = NULL;
192 	struct extent_ptr_decoded pick;
193 	struct bch_dev *ca;
194 	struct bio *bio = NULL;
195 	unsigned offset = 0;
196 	int ret;
197 
198 	if (bch2_bkey_pick_read_device(c, bkey_i_to_s_c(&b->key), NULL, &pick, -1) <= 0) {
199 		prt_printf(out, "error getting device to read from: invalid device\n");
200 		return;
201 	}
202 
203 	ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ,
204 			BCH_DEV_READ_REF_btree_node_ondisk_to_text);
205 	if (!ca) {
206 		prt_printf(out, "error getting device to read from: not online\n");
207 		return;
208 	}
209 
210 	n_ondisk = kvmalloc(btree_buf_bytes(b), GFP_KERNEL);
211 	if (!n_ondisk) {
212 		prt_printf(out, "memory allocation failure\n");
213 		goto out;
214 	}
215 
216 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
217 			       buf_pages(n_ondisk, btree_buf_bytes(b)),
218 			       REQ_OP_READ|REQ_META,
219 			       GFP_NOFS,
220 			       &c->btree_bio);
221 	bio->bi_iter.bi_sector	= pick.ptr.offset;
222 	bch2_bio_map(bio, n_ondisk, btree_buf_bytes(b));
223 
224 	ret = submit_bio_wait(bio);
225 	if (ret) {
226 		prt_printf(out, "IO error reading btree node: %s\n", bch2_err_str(ret));
227 		goto out;
228 	}
229 
230 	while (offset < btree_sectors(c)) {
231 		struct bset *i;
232 		struct nonce nonce;
233 		struct bch_csum csum;
234 		struct bkey_packed *k;
235 		unsigned sectors;
236 
237 		if (!offset) {
238 			i = &n_ondisk->keys;
239 
240 			if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
241 				prt_printf(out, "unknown checksum type at offset %u: %llu\n",
242 					   offset, BSET_CSUM_TYPE(i));
243 				goto out;
244 			}
245 
246 			nonce = btree_nonce(i, offset << 9);
247 			csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, n_ondisk);
248 
249 			if (bch2_crc_cmp(csum, n_ondisk->csum)) {
250 				prt_printf(out, "invalid checksum\n");
251 				goto out;
252 			}
253 
254 			bset_encrypt(c, i, offset << 9);
255 
256 			sectors = vstruct_sectors(n_ondisk, c->block_bits);
257 		} else {
258 			struct btree_node_entry *bne = (void *) n_ondisk + (offset << 9);
259 
260 			i = &bne->keys;
261 
262 			if (i->seq != n_ondisk->keys.seq)
263 				break;
264 
265 			if (!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i))) {
266 				prt_printf(out, "unknown checksum type at offset %u: %llu\n",
267 					   offset, BSET_CSUM_TYPE(i));
268 				goto out;
269 			}
270 
271 			nonce = btree_nonce(i, offset << 9);
272 			csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, bne);
273 
274 			if (bch2_crc_cmp(csum, bne->csum)) {
275 				prt_printf(out, "invalid checksum");
276 				goto out;
277 			}
278 
279 			bset_encrypt(c, i, offset << 9);
280 
281 			sectors = vstruct_sectors(bne, c->block_bits);
282 		}
283 
284 		prt_printf(out, "  offset %u version %u, journal seq %llu\n",
285 			   offset,
286 			   le16_to_cpu(i->version),
287 			   le64_to_cpu(i->journal_seq));
288 		offset += sectors;
289 
290 		printbuf_indent_add(out, 4);
291 
292 		for (k = i->start; k != vstruct_last(i); k = bkey_p_next(k)) {
293 			struct bkey u;
294 
295 			bch2_bkey_val_to_text(out, c, bkey_disassemble(b, k, &u));
296 			prt_newline(out);
297 		}
298 
299 		printbuf_indent_sub(out, 4);
300 	}
301 out:
302 	if (bio)
303 		bio_put(bio);
304 	kvfree(n_ondisk);
305 	enumerated_ref_put(&ca->io_ref[READ],
306 			   BCH_DEV_READ_REF_btree_node_ondisk_to_text);
307 }
308 
309 #ifdef CONFIG_DEBUG_FS
310 
bch2_debugfs_flush_buf(struct dump_iter * i)311 ssize_t bch2_debugfs_flush_buf(struct dump_iter *i)
312 {
313 	if (i->buf.pos) {
314 		size_t bytes = min_t(size_t, i->buf.pos, i->size);
315 		int copied = bytes - copy_to_user(i->ubuf, i->buf.buf, bytes);
316 
317 		i->ret	 += copied;
318 		i->ubuf	 += copied;
319 		i->size	 -= copied;
320 		i->buf.pos -= copied;
321 		memmove(i->buf.buf, i->buf.buf + copied, i->buf.pos);
322 
323 		if (i->buf.last_newline >= copied)
324 			i->buf.last_newline -= copied;
325 		if (i->buf.last_field >= copied)
326 			i->buf.last_field -= copied;
327 
328 		if (copied != bytes)
329 			return -EFAULT;
330 	}
331 
332 	return i->size ? 0 : i->ret;
333 }
334 
bch2_dump_open(struct inode * inode,struct file * file)335 static int bch2_dump_open(struct inode *inode, struct file *file)
336 {
337 	struct btree_debug *bd = inode->i_private;
338 	struct dump_iter *i;
339 
340 	i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
341 	if (!i)
342 		return -ENOMEM;
343 
344 	file->private_data = i;
345 	i->from = POS_MIN;
346 	i->iter	= 0;
347 	i->c	= container_of(bd, struct bch_fs, btree_debug[bd->id]);
348 	i->id	= bd->id;
349 	i->buf	= PRINTBUF;
350 
351 	return 0;
352 }
353 
bch2_dump_release(struct inode * inode,struct file * file)354 int bch2_dump_release(struct inode *inode, struct file *file)
355 {
356 	struct dump_iter *i = file->private_data;
357 
358 	printbuf_exit(&i->buf);
359 	kfree(i);
360 	return 0;
361 }
362 
bch2_read_btree(struct file * file,char __user * buf,size_t size,loff_t * ppos)363 static ssize_t bch2_read_btree(struct file *file, char __user *buf,
364 			       size_t size, loff_t *ppos)
365 {
366 	struct dump_iter *i = file->private_data;
367 
368 	i->ubuf = buf;
369 	i->size	= size;
370 	i->ret	= 0;
371 
372 	return bch2_debugfs_flush_buf(i) ?:
373 		bch2_trans_run(i->c,
374 			for_each_btree_key(trans, iter, i->id, i->from,
375 					   BTREE_ITER_prefetch|
376 					   BTREE_ITER_all_snapshots, k, ({
377 				bch2_bkey_val_to_text(&i->buf, i->c, k);
378 				prt_newline(&i->buf);
379 				bch2_trans_unlock(trans);
380 				i->from = bpos_successor(iter.pos);
381 				bch2_debugfs_flush_buf(i);
382 			}))) ?:
383 		i->ret;
384 }
385 
386 static const struct file_operations btree_debug_ops = {
387 	.owner		= THIS_MODULE,
388 	.open		= bch2_dump_open,
389 	.release	= bch2_dump_release,
390 	.read		= bch2_read_btree,
391 };
392 
bch2_read_btree_formats(struct file * file,char __user * buf,size_t size,loff_t * ppos)393 static ssize_t bch2_read_btree_formats(struct file *file, char __user *buf,
394 				       size_t size, loff_t *ppos)
395 {
396 	struct dump_iter *i = file->private_data;
397 
398 	i->ubuf = buf;
399 	i->size	= size;
400 	i->ret	= 0;
401 
402 	ssize_t ret = bch2_debugfs_flush_buf(i);
403 	if (ret)
404 		return ret;
405 
406 	if (bpos_eq(SPOS_MAX, i->from))
407 		return i->ret;
408 
409 	return bch2_trans_run(i->c,
410 		for_each_btree_node(trans, iter, i->id, i->from, 0, b, ({
411 			bch2_btree_node_to_text(&i->buf, i->c, b);
412 			i->from = !bpos_eq(SPOS_MAX, b->key.k.p)
413 				? bpos_successor(b->key.k.p)
414 				: b->key.k.p;
415 
416 			drop_locks_do(trans, bch2_debugfs_flush_buf(i));
417 		}))) ?: i->ret;
418 }
419 
420 static const struct file_operations btree_format_debug_ops = {
421 	.owner		= THIS_MODULE,
422 	.open		= bch2_dump_open,
423 	.release	= bch2_dump_release,
424 	.read		= bch2_read_btree_formats,
425 };
426 
bch2_read_bfloat_failed(struct file * file,char __user * buf,size_t size,loff_t * ppos)427 static ssize_t bch2_read_bfloat_failed(struct file *file, char __user *buf,
428 				       size_t size, loff_t *ppos)
429 {
430 	struct dump_iter *i = file->private_data;
431 
432 	i->ubuf = buf;
433 	i->size	= size;
434 	i->ret	= 0;
435 
436 	return bch2_debugfs_flush_buf(i) ?:
437 		bch2_trans_run(i->c,
438 			for_each_btree_key(trans, iter, i->id, i->from,
439 					   BTREE_ITER_prefetch|
440 					   BTREE_ITER_all_snapshots, k, ({
441 				struct btree_path_level *l =
442 					&btree_iter_path(trans, &iter)->l[0];
443 				struct bkey_packed *_k =
444 					bch2_btree_node_iter_peek(&l->iter, l->b);
445 
446 				if (bpos_gt(l->b->key.k.p, i->prev_node)) {
447 					bch2_btree_node_to_text(&i->buf, i->c, l->b);
448 					i->prev_node = l->b->key.k.p;
449 				}
450 
451 				bch2_bfloat_to_text(&i->buf, l->b, _k);
452 				bch2_trans_unlock(trans);
453 				i->from = bpos_successor(iter.pos);
454 				bch2_debugfs_flush_buf(i);
455 			}))) ?:
456 		i->ret;
457 }
458 
459 static const struct file_operations bfloat_failed_debug_ops = {
460 	.owner		= THIS_MODULE,
461 	.open		= bch2_dump_open,
462 	.release	= bch2_dump_release,
463 	.read		= bch2_read_bfloat_failed,
464 };
465 
bch2_cached_btree_node_to_text(struct printbuf * out,struct bch_fs * c,struct btree * b)466 static void bch2_cached_btree_node_to_text(struct printbuf *out, struct bch_fs *c,
467 					   struct btree *b)
468 {
469 	if (!out->nr_tabstops)
470 		printbuf_tabstop_push(out, 32);
471 
472 	prt_printf(out, "%px ", b);
473 	bch2_btree_id_level_to_text(out, b->c.btree_id, b->c.level);
474 	prt_printf(out, "\n");
475 
476 	printbuf_indent_add(out, 2);
477 
478 	bch2_bkey_val_to_text(out, c, bkey_i_to_s_c(&b->key));
479 	prt_newline(out);
480 
481 	prt_printf(out, "flags:\t");
482 	prt_bitflags(out, bch2_btree_node_flags, b->flags);
483 	prt_newline(out);
484 
485 	prt_printf(out, "pcpu read locks:\t%u\n",	b->c.lock.readers != NULL);
486 	prt_printf(out, "written:\t%u\n",		b->written);
487 	prt_printf(out, "writes blocked:\t%u\n",	!list_empty_careful(&b->write_blocked));
488 	prt_printf(out, "will make reachable:\t%lx\n",	b->will_make_reachable);
489 
490 	prt_printf(out, "journal pin %px:\t%llu\n",
491 		   &b->writes[0].journal, b->writes[0].journal.seq);
492 	prt_printf(out, "journal pin %px:\t%llu\n",
493 		   &b->writes[1].journal, b->writes[1].journal.seq);
494 
495 	prt_printf(out, "ob:\t%u\n", b->ob.nr);
496 
497 	printbuf_indent_sub(out, 2);
498 }
499 
bch2_cached_btree_nodes_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)500 static ssize_t bch2_cached_btree_nodes_read(struct file *file, char __user *buf,
501 					    size_t size, loff_t *ppos)
502 {
503 	struct dump_iter *i = file->private_data;
504 	struct bch_fs *c = i->c;
505 	bool done = false;
506 	ssize_t ret = 0;
507 
508 	i->ubuf = buf;
509 	i->size	= size;
510 	i->ret	= 0;
511 
512 	do {
513 		ret = bch2_debugfs_flush_buf(i);
514 		if (ret)
515 			return ret;
516 
517 		i->buf.atomic++;
518 		scoped_guard(rcu) {
519 			struct bucket_table *tbl =
520 				rht_dereference_rcu(c->btree_cache.table.tbl,
521 						    &c->btree_cache.table);
522 			if (i->iter < tbl->size) {
523 				struct rhash_head *pos;
524 				struct btree *b;
525 
526 				rht_for_each_entry_rcu(b, pos, tbl, i->iter, hash)
527 					bch2_cached_btree_node_to_text(&i->buf, c, b);
528 				i->iter++;
529 			} else {
530 				done = true;
531 			}
532 		}
533 		--i->buf.atomic;
534 	} while (!done);
535 
536 	if (i->buf.allocation_failure)
537 		ret = -ENOMEM;
538 
539 	if (!ret)
540 		ret = bch2_debugfs_flush_buf(i);
541 
542 	return ret ?: i->ret;
543 }
544 
545 static const struct file_operations cached_btree_nodes_ops = {
546 	.owner		= THIS_MODULE,
547 	.open		= bch2_dump_open,
548 	.release	= bch2_dump_release,
549 	.read		= bch2_cached_btree_nodes_read,
550 };
551 
552 typedef int (*list_cmp_fn)(const struct list_head *l, const struct list_head *r);
553 
list_sort(struct list_head * head,list_cmp_fn cmp)554 static void list_sort(struct list_head *head, list_cmp_fn cmp)
555 {
556 	struct list_head *pos;
557 
558 	list_for_each(pos, head)
559 		while (!list_is_last(pos, head) &&
560 		       cmp(pos, pos->next) > 0) {
561 			struct list_head *pos2, *next = pos->next;
562 
563 			list_del(next);
564 			list_for_each(pos2, head)
565 				if (cmp(next, pos2) < 0)
566 					goto pos_found;
567 			BUG();
568 pos_found:
569 			list_add_tail(next, pos2);
570 		}
571 }
572 
list_ptr_order_cmp(const struct list_head * l,const struct list_head * r)573 static int list_ptr_order_cmp(const struct list_head *l, const struct list_head *r)
574 {
575 	return cmp_int(l, r);
576 }
577 
bch2_btree_transactions_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)578 static ssize_t bch2_btree_transactions_read(struct file *file, char __user *buf,
579 					    size_t size, loff_t *ppos)
580 {
581 	struct dump_iter *i = file->private_data;
582 	struct bch_fs *c = i->c;
583 	struct btree_trans *trans;
584 	ssize_t ret = 0;
585 
586 	i->ubuf = buf;
587 	i->size	= size;
588 	i->ret	= 0;
589 restart:
590 	seqmutex_lock(&c->btree_trans_lock);
591 	list_sort(&c->btree_trans_list, list_ptr_order_cmp);
592 
593 	list_for_each_entry(trans, &c->btree_trans_list, list) {
594 		if ((ulong) trans <= i->iter)
595 			continue;
596 
597 		i->iter = (ulong) trans;
598 
599 		if (!closure_get_not_zero(&trans->ref))
600 			continue;
601 
602 		u32 seq = seqmutex_unlock(&c->btree_trans_lock);
603 
604 		bch2_btree_trans_to_text(&i->buf, trans);
605 
606 		prt_printf(&i->buf, "backtrace:\n");
607 		printbuf_indent_add(&i->buf, 2);
608 		bch2_prt_task_backtrace(&i->buf, trans->locking_wait.task, 0, GFP_KERNEL);
609 		printbuf_indent_sub(&i->buf, 2);
610 		prt_newline(&i->buf);
611 
612 		closure_put(&trans->ref);
613 
614 		ret = bch2_debugfs_flush_buf(i);
615 		if (ret)
616 			goto unlocked;
617 
618 		if (!seqmutex_relock(&c->btree_trans_lock, seq))
619 			goto restart;
620 	}
621 	seqmutex_unlock(&c->btree_trans_lock);
622 unlocked:
623 	if (i->buf.allocation_failure)
624 		ret = -ENOMEM;
625 
626 	if (!ret)
627 		ret = bch2_debugfs_flush_buf(i);
628 
629 	return ret ?: i->ret;
630 }
631 
632 static const struct file_operations btree_transactions_ops = {
633 	.owner		= THIS_MODULE,
634 	.open		= bch2_dump_open,
635 	.release	= bch2_dump_release,
636 	.read		= bch2_btree_transactions_read,
637 };
638 
bch2_journal_pins_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)639 static ssize_t bch2_journal_pins_read(struct file *file, char __user *buf,
640 				      size_t size, loff_t *ppos)
641 {
642 	struct dump_iter *i = file->private_data;
643 	struct bch_fs *c = i->c;
644 	bool done = false;
645 	int err;
646 
647 	i->ubuf = buf;
648 	i->size	= size;
649 	i->ret	= 0;
650 
651 	while (1) {
652 		err = bch2_debugfs_flush_buf(i);
653 		if (err)
654 			return err;
655 
656 		if (!i->size)
657 			break;
658 
659 		if (done)
660 			break;
661 
662 		done = bch2_journal_seq_pins_to_text(&i->buf, &c->journal, &i->iter);
663 		i->iter++;
664 	}
665 
666 	if (i->buf.allocation_failure)
667 		return -ENOMEM;
668 
669 	return i->ret;
670 }
671 
672 static const struct file_operations journal_pins_ops = {
673 	.owner		= THIS_MODULE,
674 	.open		= bch2_dump_open,
675 	.release	= bch2_dump_release,
676 	.read		= bch2_journal_pins_read,
677 };
678 
bch2_btree_updates_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)679 static ssize_t bch2_btree_updates_read(struct file *file, char __user *buf,
680 				       size_t size, loff_t *ppos)
681 {
682 	struct dump_iter *i = file->private_data;
683 	struct bch_fs *c = i->c;
684 	int err;
685 
686 	i->ubuf = buf;
687 	i->size	= size;
688 	i->ret	= 0;
689 
690 	if (!i->iter) {
691 		bch2_btree_updates_to_text(&i->buf, c);
692 		i->iter++;
693 	}
694 
695 	err = bch2_debugfs_flush_buf(i);
696 	if (err)
697 		return err;
698 
699 	if (i->buf.allocation_failure)
700 		return -ENOMEM;
701 
702 	return i->ret;
703 }
704 
705 static const struct file_operations btree_updates_ops = {
706 	.owner		= THIS_MODULE,
707 	.open		= bch2_dump_open,
708 	.release	= bch2_dump_release,
709 	.read		= bch2_btree_updates_read,
710 };
711 
btree_transaction_stats_open(struct inode * inode,struct file * file)712 static int btree_transaction_stats_open(struct inode *inode, struct file *file)
713 {
714 	struct bch_fs *c = inode->i_private;
715 	struct dump_iter *i;
716 
717 	i = kzalloc(sizeof(struct dump_iter), GFP_KERNEL);
718 	if (!i)
719 		return -ENOMEM;
720 
721 	i->iter = 1;
722 	i->c    = c;
723 	i->buf  = PRINTBUF;
724 	file->private_data = i;
725 
726 	return 0;
727 }
728 
btree_transaction_stats_release(struct inode * inode,struct file * file)729 static int btree_transaction_stats_release(struct inode *inode, struct file *file)
730 {
731 	struct dump_iter *i = file->private_data;
732 
733 	printbuf_exit(&i->buf);
734 	kfree(i);
735 
736 	return 0;
737 }
738 
btree_transaction_stats_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)739 static ssize_t btree_transaction_stats_read(struct file *file, char __user *buf,
740 					    size_t size, loff_t *ppos)
741 {
742 	struct dump_iter        *i = file->private_data;
743 	struct bch_fs *c = i->c;
744 	int err;
745 
746 	i->ubuf = buf;
747 	i->size = size;
748 	i->ret  = 0;
749 
750 	while (1) {
751 		struct btree_transaction_stats *s = &c->btree_transaction_stats[i->iter];
752 
753 		err = bch2_debugfs_flush_buf(i);
754 		if (err)
755 			return err;
756 
757 		if (!i->size)
758 			break;
759 
760 		if (i->iter == ARRAY_SIZE(bch2_btree_transaction_fns) ||
761 		    !bch2_btree_transaction_fns[i->iter])
762 			break;
763 
764 		prt_printf(&i->buf, "%s:\n", bch2_btree_transaction_fns[i->iter]);
765 		printbuf_indent_add(&i->buf, 2);
766 
767 		mutex_lock(&s->lock);
768 
769 		prt_printf(&i->buf, "Max mem used: %u\n", s->max_mem);
770 #ifdef CONFIG_BCACHEFS_TRANS_KMALLOC_TRACE
771 		printbuf_indent_add(&i->buf, 2);
772 		bch2_trans_kmalloc_trace_to_text(&i->buf, &s->trans_kmalloc_trace);
773 		printbuf_indent_sub(&i->buf, 2);
774 #endif
775 
776 		prt_printf(&i->buf, "Transaction duration:\n");
777 
778 		printbuf_indent_add(&i->buf, 2);
779 		bch2_time_stats_to_text(&i->buf, &s->duration);
780 		printbuf_indent_sub(&i->buf, 2);
781 
782 		if (IS_ENABLED(CONFIG_BCACHEFS_LOCK_TIME_STATS)) {
783 			prt_printf(&i->buf, "Lock hold times:\n");
784 
785 			printbuf_indent_add(&i->buf, 2);
786 			bch2_time_stats_to_text(&i->buf, &s->lock_hold_times);
787 			printbuf_indent_sub(&i->buf, 2);
788 		}
789 
790 		if (s->max_paths_text) {
791 			prt_printf(&i->buf, "Maximum allocated btree paths (%u):\n", s->nr_max_paths);
792 
793 			printbuf_indent_add(&i->buf, 2);
794 			prt_str_indented(&i->buf, s->max_paths_text);
795 			printbuf_indent_sub(&i->buf, 2);
796 		}
797 
798 		mutex_unlock(&s->lock);
799 
800 		printbuf_indent_sub(&i->buf, 2);
801 		prt_newline(&i->buf);
802 		i->iter++;
803 	}
804 
805 	if (i->buf.allocation_failure)
806 		return -ENOMEM;
807 
808 	return i->ret;
809 }
810 
811 static const struct file_operations btree_transaction_stats_op = {
812 	.owner		= THIS_MODULE,
813 	.open		= btree_transaction_stats_open,
814 	.release	= btree_transaction_stats_release,
815 	.read		= btree_transaction_stats_read,
816 };
817 
818 /* walk btree transactions until we find a deadlock and print it */
btree_deadlock_to_text(struct printbuf * out,struct bch_fs * c)819 static void btree_deadlock_to_text(struct printbuf *out, struct bch_fs *c)
820 {
821 	struct btree_trans *trans;
822 	ulong iter = 0;
823 restart:
824 	seqmutex_lock(&c->btree_trans_lock);
825 	list_sort(&c->btree_trans_list, list_ptr_order_cmp);
826 
827 	list_for_each_entry(trans, &c->btree_trans_list, list) {
828 		if ((ulong) trans <= iter)
829 			continue;
830 
831 		iter = (ulong) trans;
832 
833 		if (!closure_get_not_zero(&trans->ref))
834 			continue;
835 
836 		u32 seq = seqmutex_unlock(&c->btree_trans_lock);
837 
838 		bool found = bch2_check_for_deadlock(trans, out) != 0;
839 
840 		closure_put(&trans->ref);
841 
842 		if (found)
843 			return;
844 
845 		if (!seqmutex_relock(&c->btree_trans_lock, seq))
846 			goto restart;
847 	}
848 	seqmutex_unlock(&c->btree_trans_lock);
849 }
850 
851 typedef void (*fs_to_text_fn)(struct printbuf *, struct bch_fs *);
852 
bch2_simple_print(struct file * file,char __user * buf,size_t size,loff_t * ppos,fs_to_text_fn fn)853 static ssize_t bch2_simple_print(struct file *file, char __user *buf,
854 				 size_t size, loff_t *ppos,
855 				 fs_to_text_fn fn)
856 {
857 	struct dump_iter *i = file->private_data;
858 	struct bch_fs *c = i->c;
859 	ssize_t ret = 0;
860 
861 	i->ubuf = buf;
862 	i->size	= size;
863 	i->ret	= 0;
864 
865 	if (!i->iter) {
866 		fn(&i->buf, c);
867 		i->iter++;
868 	}
869 
870 	if (i->buf.allocation_failure)
871 		ret = -ENOMEM;
872 
873 	if (!ret)
874 		ret = bch2_debugfs_flush_buf(i);
875 
876 	return ret ?: i->ret;
877 }
878 
bch2_btree_deadlock_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)879 static ssize_t bch2_btree_deadlock_read(struct file *file, char __user *buf,
880 					size_t size, loff_t *ppos)
881 {
882 	return bch2_simple_print(file, buf, size, ppos, btree_deadlock_to_text);
883 }
884 
885 static const struct file_operations btree_deadlock_ops = {
886 	.owner		= THIS_MODULE,
887 	.open		= bch2_dump_open,
888 	.release	= bch2_dump_release,
889 	.read		= bch2_btree_deadlock_read,
890 };
891 
bch2_write_points_read(struct file * file,char __user * buf,size_t size,loff_t * ppos)892 static ssize_t bch2_write_points_read(struct file *file, char __user *buf,
893 				     size_t size, loff_t *ppos)
894 {
895 	return bch2_simple_print(file, buf, size, ppos, bch2_write_points_to_text);
896 }
897 
898 static const struct file_operations write_points_ops = {
899 	.owner		= THIS_MODULE,
900 	.open		= bch2_dump_open,
901 	.release	= bch2_dump_release,
902 	.read		= bch2_write_points_read,
903 };
904 
bch2_fs_debug_exit(struct bch_fs * c)905 void bch2_fs_debug_exit(struct bch_fs *c)
906 {
907 	if (!IS_ERR_OR_NULL(c->fs_debug_dir))
908 		debugfs_remove_recursive(c->fs_debug_dir);
909 }
910 
bch2_fs_debug_btree_init(struct bch_fs * c,struct btree_debug * bd)911 static void bch2_fs_debug_btree_init(struct bch_fs *c, struct btree_debug *bd)
912 {
913 	struct dentry *d;
914 
915 	d = debugfs_create_dir(bch2_btree_id_str(bd->id), c->btree_debug_dir);
916 
917 	debugfs_create_file("keys", 0400, d, bd, &btree_debug_ops);
918 
919 	debugfs_create_file("formats", 0400, d, bd, &btree_format_debug_ops);
920 
921 	debugfs_create_file("bfloat-failed", 0400, d, bd,
922 			    &bfloat_failed_debug_ops);
923 }
924 
bch2_fs_debug_init(struct bch_fs * c)925 void bch2_fs_debug_init(struct bch_fs *c)
926 {
927 	struct btree_debug *bd;
928 	char name[100];
929 
930 	if (IS_ERR_OR_NULL(bch_debug))
931 		return;
932 
933 	if (c->sb.multi_device)
934 		snprintf(name, sizeof(name), "%pU", c->sb.user_uuid.b);
935 	else
936 		strscpy(name, c->name, sizeof(name));
937 
938 	c->fs_debug_dir = debugfs_create_dir(name, bch_debug);
939 	if (IS_ERR_OR_NULL(c->fs_debug_dir))
940 		return;
941 
942 	debugfs_create_file("cached_btree_nodes", 0400, c->fs_debug_dir,
943 			    c->btree_debug, &cached_btree_nodes_ops);
944 
945 	debugfs_create_file("btree_transactions", 0400, c->fs_debug_dir,
946 			    c->btree_debug, &btree_transactions_ops);
947 
948 	debugfs_create_file("journal_pins", 0400, c->fs_debug_dir,
949 			    c->btree_debug, &journal_pins_ops);
950 
951 	debugfs_create_file("btree_updates", 0400, c->fs_debug_dir,
952 			    c->btree_debug, &btree_updates_ops);
953 
954 	debugfs_create_file("btree_transaction_stats", 0400, c->fs_debug_dir,
955 			    c, &btree_transaction_stats_op);
956 
957 	debugfs_create_file("btree_deadlock", 0400, c->fs_debug_dir,
958 			    c->btree_debug, &btree_deadlock_ops);
959 
960 	debugfs_create_file("write_points", 0400, c->fs_debug_dir,
961 			    c->btree_debug, &write_points_ops);
962 
963 	bch2_fs_async_obj_debugfs_init(c);
964 
965 	c->btree_debug_dir = debugfs_create_dir("btrees", c->fs_debug_dir);
966 	if (IS_ERR_OR_NULL(c->btree_debug_dir))
967 		return;
968 
969 	for (bd = c->btree_debug;
970 	     bd < c->btree_debug + ARRAY_SIZE(c->btree_debug);
971 	     bd++) {
972 		bd->id = bd - c->btree_debug;
973 		bch2_fs_debug_btree_init(c, bd);
974 	}
975 }
976 
977 #endif
978 
bch2_debug_exit(void)979 void bch2_debug_exit(void)
980 {
981 	if (!IS_ERR_OR_NULL(bch_debug))
982 		debugfs_remove_recursive(bch_debug);
983 }
984 
bch2_debug_init(void)985 int __init bch2_debug_init(void)
986 {
987 	bch_debug = debugfs_create_dir("bcachefs", NULL);
988 	return 0;
989 }
990