xref: /linux/fs/bcachefs/error.c (revision f694f30e81c4ade358eb8c75273bac1a48f0cb8f)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "bcachefs.h"
3 #include "btree_cache.h"
4 #include "btree_iter.h"
5 #include "error.h"
6 #include "journal.h"
7 #include "namei.h"
8 #include "recovery_passes.h"
9 #include "super.h"
10 #include "thread_with_file.h"
11 
12 #define FSCK_ERR_RATELIMIT_NR	10
13 
14 void bch2_log_msg_start(struct bch_fs *c, struct printbuf *out)
15 {
16 	printbuf_indent_add_nextline(out, 2);
17 
18 #ifdef BCACHEFS_LOG_PREFIX
19 	prt_printf(out, bch2_log_msg(c, ""));
20 #endif
21 }
22 
23 bool __bch2_inconsistent_error(struct bch_fs *c, struct printbuf *out)
24 {
25 	set_bit(BCH_FS_error, &c->flags);
26 
27 	switch (c->opts.errors) {
28 	case BCH_ON_ERROR_continue:
29 		return false;
30 	case BCH_ON_ERROR_fix_safe:
31 	case BCH_ON_ERROR_ro:
32 		if (bch2_fs_emergency_read_only(c))
33 			prt_printf(out, "inconsistency detected - emergency read only at journal seq %llu\n",
34 				   journal_cur_seq(&c->journal));
35 		return true;
36 	case BCH_ON_ERROR_panic:
37 		bch2_print_string_as_lines_nonblocking(KERN_ERR, out->buf);
38 		panic(bch2_fmt(c, "panic after error"));
39 		return true;
40 	default:
41 		BUG();
42 	}
43 }
44 
45 bool bch2_inconsistent_error(struct bch_fs *c)
46 {
47 	struct printbuf buf = PRINTBUF;
48 	buf.atomic++;
49 
50 	printbuf_indent_add_nextline(&buf, 2);
51 
52 	bool ret = __bch2_inconsistent_error(c, &buf);
53 	if (ret)
54 		bch_err(c, "%s", buf.buf);
55 	printbuf_exit(&buf);
56 	return ret;
57 }
58 
59 __printf(3, 0)
60 static bool bch2_fs_trans_inconsistent(struct bch_fs *c, struct btree_trans *trans,
61 				       const char *fmt, va_list args)
62 {
63 	struct printbuf buf = PRINTBUF;
64 	buf.atomic++;
65 
66 	bch2_log_msg_start(c, &buf);
67 
68 	prt_vprintf(&buf, fmt, args);
69 	prt_newline(&buf);
70 
71 	if (trans)
72 		bch2_trans_updates_to_text(&buf, trans);
73 	bool ret = __bch2_inconsistent_error(c, &buf);
74 	bch2_print_string_as_lines_nonblocking(KERN_ERR, buf.buf);
75 
76 	printbuf_exit(&buf);
77 	return ret;
78 }
79 
80 bool bch2_fs_inconsistent(struct bch_fs *c, const char *fmt, ...)
81 {
82 	va_list args;
83 	va_start(args, fmt);
84 	bool ret = bch2_fs_trans_inconsistent(c, NULL, fmt, args);
85 	va_end(args);
86 	return ret;
87 }
88 
89 bool bch2_trans_inconsistent(struct btree_trans *trans, const char *fmt, ...)
90 {
91 	va_list args;
92 	va_start(args, fmt);
93 	bool ret = bch2_fs_trans_inconsistent(trans->c, trans, fmt, args);
94 	va_end(args);
95 	return ret;
96 }
97 
98 int __bch2_topology_error(struct bch_fs *c, struct printbuf *out)
99 {
100 	prt_printf(out, "btree topology error: ");
101 
102 	set_bit(BCH_FS_topology_error, &c->flags);
103 	if (!test_bit(BCH_FS_recovery_running, &c->flags)) {
104 		__bch2_inconsistent_error(c, out);
105 		return -BCH_ERR_btree_need_topology_repair;
106 	} else {
107 		return bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_check_topology) ?:
108 			-BCH_ERR_btree_node_read_validate_error;
109 	}
110 }
111 
112 int bch2_fs_topology_error(struct bch_fs *c, const char *fmt, ...)
113 {
114 	struct printbuf buf = PRINTBUF;
115 
116 	bch2_log_msg_start(c, &buf);
117 
118 	va_list args;
119 	va_start(args, fmt);
120 	prt_vprintf(&buf, fmt, args);
121 	va_end(args);
122 
123 	int ret = __bch2_topology_error(c, &buf);
124 	bch2_print_string_as_lines(KERN_ERR, buf.buf);
125 
126 	printbuf_exit(&buf);
127 	return ret;
128 }
129 
130 void bch2_fatal_error(struct bch_fs *c)
131 {
132 	if (bch2_fs_emergency_read_only(c))
133 		bch_err(c, "fatal error - emergency read only");
134 }
135 
136 void bch2_io_error_work(struct work_struct *work)
137 {
138 	struct bch_dev *ca = container_of(work, struct bch_dev, io_error_work);
139 	struct bch_fs *c = ca->fs;
140 
141 	/* XXX: if it's reads or checksums that are failing, set it to failed */
142 
143 	down_write(&c->state_lock);
144 	unsigned long write_errors_start = READ_ONCE(ca->write_errors_start);
145 
146 	if (write_errors_start &&
147 	    time_after(jiffies,
148 		       write_errors_start + c->opts.write_error_timeout * HZ)) {
149 		if (ca->mi.state >= BCH_MEMBER_STATE_ro)
150 			goto out;
151 
152 		bool dev = !__bch2_dev_set_state(c, ca, BCH_MEMBER_STATE_ro,
153 						 BCH_FORCE_IF_DEGRADED);
154 
155 		bch_err(ca,
156 			"writes erroring for %u seconds, setting %s ro",
157 			c->opts.write_error_timeout,
158 			dev ? "device" : "filesystem");
159 		if (!dev)
160 			bch2_fs_emergency_read_only(c);
161 
162 	}
163 out:
164 	up_write(&c->state_lock);
165 }
166 
167 void bch2_io_error(struct bch_dev *ca, enum bch_member_error_type type)
168 {
169 	atomic64_inc(&ca->errors[type]);
170 
171 	if (type == BCH_MEMBER_ERROR_write && !ca->write_errors_start)
172 		ca->write_errors_start = jiffies;
173 
174 	queue_work(system_long_wq, &ca->io_error_work);
175 }
176 
177 enum ask_yn {
178 	YN_NO,
179 	YN_YES,
180 	YN_ALLNO,
181 	YN_ALLYES,
182 };
183 
184 static enum ask_yn parse_yn_response(char *buf)
185 {
186 	buf = strim(buf);
187 
188 	if (strlen(buf) == 1)
189 		switch (buf[0]) {
190 		case 'n':
191 			return YN_NO;
192 		case 'y':
193 			return YN_YES;
194 		case 'N':
195 			return YN_ALLNO;
196 		case 'Y':
197 			return YN_ALLYES;
198 		}
199 	return -1;
200 }
201 
202 #ifdef __KERNEL__
203 static enum ask_yn bch2_fsck_ask_yn(struct bch_fs *c, struct btree_trans *trans)
204 {
205 	struct stdio_redirect *stdio = c->stdio;
206 
207 	if (c->stdio_filter && c->stdio_filter != current)
208 		stdio = NULL;
209 
210 	if (!stdio)
211 		return YN_NO;
212 
213 	if (trans)
214 		bch2_trans_unlock(trans);
215 
216 	unsigned long unlock_long_at = trans ? jiffies + HZ * 2 : 0;
217 	darray_char line = {};
218 	int ret;
219 
220 	do {
221 		unsigned long t;
222 		bch2_print(c, " (y,n, or Y,N for all errors of this type) ");
223 rewait:
224 		t = unlock_long_at
225 			? max_t(long, unlock_long_at - jiffies, 0)
226 			: MAX_SCHEDULE_TIMEOUT;
227 
228 		int r = bch2_stdio_redirect_readline_timeout(stdio, &line, t);
229 		if (r == -ETIME) {
230 			bch2_trans_unlock_long(trans);
231 			unlock_long_at = 0;
232 			goto rewait;
233 		}
234 
235 		if (r < 0) {
236 			ret = YN_NO;
237 			break;
238 		}
239 
240 		darray_last(line) = '\0';
241 	} while ((ret = parse_yn_response(line.data)) < 0);
242 
243 	darray_exit(&line);
244 	return ret;
245 }
246 #else
247 
248 #include "tools-util.h"
249 
250 static enum ask_yn bch2_fsck_ask_yn(struct bch_fs *c, struct btree_trans *trans)
251 {
252 	char *buf = NULL;
253 	size_t buflen = 0;
254 	int ret;
255 
256 	do {
257 		fputs(" (y,n, or Y,N for all errors of this type) ", stdout);
258 		fflush(stdout);
259 
260 		if (getline(&buf, &buflen, stdin) < 0)
261 			die("error reading from standard input");
262 	} while ((ret = parse_yn_response(buf)) < 0);
263 
264 	free(buf);
265 	return ret;
266 }
267 
268 #endif
269 
270 static struct fsck_err_state *fsck_err_get(struct bch_fs *c,
271 					   enum bch_sb_error_id id)
272 {
273 	struct fsck_err_state *s;
274 
275 	if (!test_bit(BCH_FS_fsck_running, &c->flags))
276 		return NULL;
277 
278 	list_for_each_entry(s, &c->fsck_error_msgs, list)
279 		if (s->id == id) {
280 			/*
281 			 * move it to the head of the list: repeated fsck errors
282 			 * are common
283 			 */
284 			list_move(&s->list, &c->fsck_error_msgs);
285 			return s;
286 		}
287 
288 	s = kzalloc(sizeof(*s), GFP_NOFS);
289 	if (!s) {
290 		if (!c->fsck_alloc_msgs_err)
291 			bch_err(c, "kmalloc err, cannot ratelimit fsck errs");
292 		c->fsck_alloc_msgs_err = true;
293 		return NULL;
294 	}
295 
296 	INIT_LIST_HEAD(&s->list);
297 	s->id = id;
298 	list_add(&s->list, &c->fsck_error_msgs);
299 	return s;
300 }
301 
302 /* s/fix?/fixing/ s/recreate?/recreating/ */
303 static void prt_actioning(struct printbuf *out, const char *action)
304 {
305 	unsigned len = strlen(action);
306 
307 	BUG_ON(action[len - 1] != '?');
308 	--len;
309 
310 	if (action[len - 1] == 'e')
311 		--len;
312 
313 	prt_bytes(out, action, len);
314 	prt_str(out, "ing");
315 }
316 
317 static const u8 fsck_flags_extra[] = {
318 #define x(t, n, flags)		[BCH_FSCK_ERR_##t] = flags,
319 	BCH_SB_ERRS()
320 #undef x
321 };
322 
323 static int do_fsck_ask_yn(struct bch_fs *c,
324 			  struct btree_trans *trans,
325 			  struct printbuf *question,
326 			  const char *action)
327 {
328 	prt_str(question, ", ");
329 	prt_str(question, action);
330 
331 	if (bch2_fs_stdio_redirect(c))
332 		bch2_print(c, "%s", question->buf);
333 	else
334 		bch2_print_string_as_lines(KERN_ERR, question->buf);
335 
336 	int ask = bch2_fsck_ask_yn(c, trans);
337 
338 	if (trans) {
339 		int ret = bch2_trans_relock(trans);
340 		if (ret)
341 			return ret;
342 	}
343 
344 	return ask;
345 }
346 
347 static struct fsck_err_state *count_fsck_err_locked(struct bch_fs *c,
348 			  enum bch_sb_error_id id, const char *msg,
349 			  bool *repeat, bool *print, bool *suppress)
350 {
351 	bch2_sb_error_count(c, id);
352 
353 	struct fsck_err_state *s = fsck_err_get(c, id);
354 	if (s) {
355 		/*
356 		 * We may be called multiple times for the same error on
357 		 * transaction restart - this memoizes instead of asking the user
358 		 * multiple times for the same error:
359 		 */
360 		if (s->last_msg && !strcmp(msg, s->last_msg)) {
361 			*repeat = true;
362 			*print = false;
363 			return s;
364 		}
365 
366 		kfree(s->last_msg);
367 		s->last_msg = kstrdup(msg, GFP_KERNEL);
368 
369 		if (c->opts.ratelimit_errors &&
370 		    s->nr >= FSCK_ERR_RATELIMIT_NR) {
371 			if (s->nr == FSCK_ERR_RATELIMIT_NR)
372 				*suppress = true;
373 			else
374 				*print = false;
375 		}
376 
377 		s->nr++;
378 	}
379 	return s;
380 }
381 
382 void __bch2_count_fsck_err(struct bch_fs *c,
383 			   enum bch_sb_error_id id, const char *msg,
384 			   bool *repeat, bool *print, bool *suppress)
385 {
386 	bch2_sb_error_count(c, id);
387 
388 	mutex_lock(&c->fsck_error_msgs_lock);
389 	count_fsck_err_locked(c, id, msg, repeat, print, suppress);
390 	mutex_unlock(&c->fsck_error_msgs_lock);
391 }
392 
393 int __bch2_fsck_err(struct bch_fs *c,
394 		  struct btree_trans *trans,
395 		  enum bch_fsck_flags flags,
396 		  enum bch_sb_error_id err,
397 		  const char *fmt, ...)
398 {
399 	va_list args;
400 	struct printbuf buf = PRINTBUF, *out = &buf;
401 	int ret = -BCH_ERR_fsck_ignore;
402 	const char *action_orig = "fix?", *action = action_orig;
403 
404 	might_sleep();
405 
406 	if (!WARN_ON(err >= ARRAY_SIZE(fsck_flags_extra)))
407 		flags |= fsck_flags_extra[err];
408 
409 	if (!c)
410 		c = trans->c;
411 
412 	/*
413 	 * Ugly: if there's a transaction in the current task it has to be
414 	 * passed in to unlock if we prompt for user input.
415 	 *
416 	 * But, plumbing a transaction and transaction restarts into
417 	 * bkey_validate() is problematic.
418 	 *
419 	 * So:
420 	 * - make all bkey errors AUTOFIX, they're simple anyways (we just
421 	 *   delete the key)
422 	 * - and we don't need to warn if we're not prompting
423 	 */
424 	WARN_ON((flags & FSCK_CAN_FIX) &&
425 		!(flags & FSCK_AUTOFIX) &&
426 		!trans &&
427 		bch2_current_has_btree_trans(c));
428 
429 	if (test_bit(err, c->sb.errors_silent))
430 		return flags & FSCK_CAN_FIX
431 			? -BCH_ERR_fsck_fix
432 			: -BCH_ERR_fsck_ignore;
433 
434 	printbuf_indent_add_nextline(out, 2);
435 
436 #ifdef BCACHEFS_LOG_PREFIX
437 	if (strncmp(fmt, "bcachefs", 8))
438 		prt_printf(out, bch2_log_msg(c, ""));
439 #endif
440 
441 	va_start(args, fmt);
442 	prt_vprintf(out, fmt, args);
443 	va_end(args);
444 
445 	/* Custom fix/continue/recreate/etc.? */
446 	if (out->buf[out->pos - 1] == '?') {
447 		const char *p = strrchr(out->buf, ',');
448 		if (p) {
449 			out->pos = p - out->buf;
450 			action = kstrdup(p + 2, GFP_KERNEL);
451 			if (!action) {
452 				ret = -ENOMEM;
453 				goto err;
454 			}
455 		}
456 	}
457 
458 	mutex_lock(&c->fsck_error_msgs_lock);
459 	bool repeat = false, print = true, suppress = false;
460 	bool inconsistent = false, exiting = false;
461 	struct fsck_err_state *s =
462 		count_fsck_err_locked(c, err, buf.buf, &repeat, &print, &suppress);
463 	if (repeat) {
464 		ret = s->ret;
465 		goto err_unlock;
466 	}
467 
468 	if ((flags & FSCK_AUTOFIX) &&
469 	    (c->opts.errors == BCH_ON_ERROR_continue ||
470 	     c->opts.errors == BCH_ON_ERROR_fix_safe)) {
471 		prt_str(out, ", ");
472 		if (flags & FSCK_CAN_FIX) {
473 			prt_actioning(out, action);
474 			ret = -BCH_ERR_fsck_fix;
475 		} else {
476 			prt_str(out, ", continuing");
477 			ret = -BCH_ERR_fsck_ignore;
478 		}
479 
480 		goto print;
481 	} else if (!test_bit(BCH_FS_fsck_running, &c->flags)) {
482 		if (c->opts.errors != BCH_ON_ERROR_continue ||
483 		    !(flags & (FSCK_CAN_FIX|FSCK_CAN_IGNORE))) {
484 			prt_str(out, ", shutting down");
485 			inconsistent = true;
486 			print = true;
487 			ret = -BCH_ERR_fsck_errors_not_fixed;
488 		} else if (flags & FSCK_CAN_FIX) {
489 			prt_str(out, ", ");
490 			prt_actioning(out, action);
491 			ret = -BCH_ERR_fsck_fix;
492 		} else {
493 			prt_str(out, ", continuing");
494 			ret = -BCH_ERR_fsck_ignore;
495 		}
496 	} else if (c->opts.fix_errors == FSCK_FIX_exit) {
497 		prt_str(out, ", exiting");
498 		ret = -BCH_ERR_fsck_errors_not_fixed;
499 	} else if (flags & FSCK_CAN_FIX) {
500 		int fix = s && s->fix
501 			? s->fix
502 			: c->opts.fix_errors;
503 
504 		if (fix == FSCK_FIX_ask) {
505 			print = false;
506 
507 			ret = do_fsck_ask_yn(c, trans, out, action);
508 			if (ret < 0)
509 				goto err_unlock;
510 
511 			if (ret >= YN_ALLNO && s)
512 				s->fix = ret == YN_ALLNO
513 					? FSCK_FIX_no
514 					: FSCK_FIX_yes;
515 
516 			ret = ret & 1
517 				? -BCH_ERR_fsck_fix
518 				: -BCH_ERR_fsck_ignore;
519 		} else if (fix == FSCK_FIX_yes ||
520 			   (c->opts.nochanges &&
521 			    !(flags & FSCK_CAN_IGNORE))) {
522 			prt_str(out, ", ");
523 			prt_actioning(out, action);
524 			ret = -BCH_ERR_fsck_fix;
525 		} else {
526 			prt_str(out, ", not ");
527 			prt_actioning(out, action);
528 		}
529 	} else if (!(flags & FSCK_CAN_IGNORE)) {
530 		prt_str(out, " (repair unimplemented)");
531 	}
532 
533 	if (ret == -BCH_ERR_fsck_ignore &&
534 	    (c->opts.fix_errors == FSCK_FIX_exit ||
535 	     !(flags & FSCK_CAN_IGNORE)))
536 		ret = -BCH_ERR_fsck_errors_not_fixed;
537 
538 	if (test_bit(BCH_FS_fsck_running, &c->flags) &&
539 	    (ret != -BCH_ERR_fsck_fix &&
540 	     ret != -BCH_ERR_fsck_ignore)) {
541 		exiting = true;
542 		print = true;
543 	}
544 print:
545 	prt_newline(out);
546 
547 	if (inconsistent)
548 		__bch2_inconsistent_error(c, out);
549 	else if (exiting)
550 		prt_printf(out, "Unable to continue, halting\n");
551 	else if (suppress)
552 		prt_printf(out, "Ratelimiting new instances of previous error\n");
553 
554 	if (print) {
555 		/* possibly strip an empty line, from printbuf_indent_add */
556 		while (out->pos && out->buf[out->pos - 1] == ' ')
557 			--out->pos;
558 		printbuf_nul_terminate(out);
559 
560 		if (bch2_fs_stdio_redirect(c))
561 			bch2_print(c, "%s", out->buf);
562 		else
563 			bch2_print_string_as_lines(KERN_ERR, out->buf);
564 	}
565 
566 	if (s)
567 		s->ret = ret;
568 
569 	/*
570 	 * We don't yet track whether the filesystem currently has errors, for
571 	 * log_fsck_err()s: that would require us to track for every error type
572 	 * which recovery pass corrects it, to get the fsck exit status correct:
573 	 */
574 	if (flags & FSCK_CAN_FIX) {
575 		if (ret == -BCH_ERR_fsck_fix) {
576 			set_bit(BCH_FS_errors_fixed, &c->flags);
577 		} else {
578 			set_bit(BCH_FS_errors_not_fixed, &c->flags);
579 			set_bit(BCH_FS_error, &c->flags);
580 		}
581 	}
582 err_unlock:
583 	mutex_unlock(&c->fsck_error_msgs_lock);
584 err:
585 	if (action != action_orig)
586 		kfree(action);
587 	printbuf_exit(&buf);
588 	return ret;
589 }
590 
591 static const char * const bch2_bkey_validate_contexts[] = {
592 #define x(n) #n,
593 	BKEY_VALIDATE_CONTEXTS()
594 #undef x
595 	NULL
596 };
597 
598 int __bch2_bkey_fsck_err(struct bch_fs *c,
599 			 struct bkey_s_c k,
600 			 struct bkey_validate_context from,
601 			 enum bch_sb_error_id err,
602 			 const char *fmt, ...)
603 {
604 	if (from.flags & BCH_VALIDATE_silent)
605 		return -BCH_ERR_fsck_delete_bkey;
606 
607 	unsigned fsck_flags = 0;
608 	if (!(from.flags & (BCH_VALIDATE_write|BCH_VALIDATE_commit))) {
609 		if (test_bit(err, c->sb.errors_silent))
610 			return -BCH_ERR_fsck_delete_bkey;
611 
612 		fsck_flags |= FSCK_AUTOFIX|FSCK_CAN_FIX;
613 	}
614 	if (!WARN_ON(err >= ARRAY_SIZE(fsck_flags_extra)))
615 		fsck_flags |= fsck_flags_extra[err];
616 
617 	struct printbuf buf = PRINTBUF;
618 	prt_printf(&buf, "invalid bkey in %s",
619 		   bch2_bkey_validate_contexts[from.from]);
620 
621 	if (from.from == BKEY_VALIDATE_journal)
622 		prt_printf(&buf, " journal seq=%llu offset=%u",
623 			   from.journal_seq, from.journal_offset);
624 
625 	prt_str(&buf, " btree=");
626 	bch2_btree_id_to_text(&buf, from.btree);
627 	prt_printf(&buf, " level=%u: ", from.level);
628 
629 	bch2_bkey_val_to_text(&buf, c, k);
630 	prt_newline(&buf);
631 
632 	va_list args;
633 	va_start(args, fmt);
634 	prt_vprintf(&buf, fmt, args);
635 	va_end(args);
636 
637 	int ret = __bch2_fsck_err(c, NULL, fsck_flags, err, "%s, delete?", buf.buf);
638 	printbuf_exit(&buf);
639 	return ret;
640 }
641 
642 void bch2_flush_fsck_errs(struct bch_fs *c)
643 {
644 	struct fsck_err_state *s, *n;
645 
646 	mutex_lock(&c->fsck_error_msgs_lock);
647 
648 	list_for_each_entry_safe(s, n, &c->fsck_error_msgs, list) {
649 		if (s->ratelimited && s->last_msg)
650 			bch_err(c, "Saw %llu errors like:\n  %s", s->nr, s->last_msg);
651 
652 		list_del(&s->list);
653 		kfree(s->last_msg);
654 		kfree(s);
655 	}
656 
657 	mutex_unlock(&c->fsck_error_msgs_lock);
658 }
659 
660 int bch2_inum_offset_err_msg_trans(struct btree_trans *trans, struct printbuf *out,
661 				    subvol_inum inum, u64 offset)
662 {
663 	u32 restart_count = trans->restart_count;
664 	int ret = 0;
665 
666 	if (inum.subvol) {
667 		ret = bch2_inum_to_path(trans, inum, out);
668 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
669 			return ret;
670 	}
671 	if (!inum.subvol || ret)
672 		prt_printf(out, "inum %llu:%llu", inum.subvol, inum.inum);
673 	prt_printf(out, " offset %llu: ", offset);
674 
675 	return trans_was_restarted(trans, restart_count);
676 }
677 
678 void bch2_inum_offset_err_msg(struct bch_fs *c, struct printbuf *out,
679 			      subvol_inum inum, u64 offset)
680 {
681 	bch2_trans_do(c, bch2_inum_offset_err_msg_trans(trans, out, inum, offset));
682 }
683 
684 int bch2_inum_snap_offset_err_msg_trans(struct btree_trans *trans, struct printbuf *out,
685 					struct bpos pos)
686 {
687 	struct bch_fs *c = trans->c;
688 	int ret = 0;
689 
690 	if (!bch2_snapshot_is_leaf(c, pos.snapshot))
691 		prt_str(out, "(multiple snapshots) ");
692 
693 	subvol_inum inum = {
694 		.subvol	= bch2_snapshot_tree_oldest_subvol(c, pos.snapshot),
695 		.inum	= pos.inode,
696 	};
697 
698 	if (inum.subvol) {
699 		ret = bch2_inum_to_path(trans, inum, out);
700 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
701 			return ret;
702 	}
703 
704 	if (!inum.subvol || ret)
705 		prt_printf(out, "inum %llu:%u", pos.inode, pos.snapshot);
706 
707 	prt_printf(out, " offset %llu: ", pos.offset << 8);
708 	return 0;
709 }
710 
711 void bch2_inum_snap_offset_err_msg(struct bch_fs *c, struct printbuf *out,
712 				  struct bpos pos)
713 {
714 	bch2_trans_do(c, bch2_inum_snap_offset_err_msg_trans(trans, out, pos));
715 }
716