xref: /linux/fs/xfs/xfs_sysfs.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2014 Red Hat, Inc.
4  * All Rights Reserved.
5  */
6 
7 #include "xfs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_sysfs.h"
13 #include "xfs_log.h"
14 #include "xfs_log_priv.h"
15 #include "xfs_mount.h"
16 
17 struct xfs_sysfs_attr {
18 	struct attribute attr;
19 	ssize_t (*show)(struct kobject *kobject, char *buf);
20 	ssize_t (*store)(struct kobject *kobject, const char *buf,
21 			 size_t count);
22 };
23 
24 static inline struct xfs_sysfs_attr *
25 to_attr(struct attribute *attr)
26 {
27 	return container_of(attr, struct xfs_sysfs_attr, attr);
28 }
29 
30 #define XFS_SYSFS_ATTR_RW(name) \
31 	static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_RW(name)
32 #define XFS_SYSFS_ATTR_RO(name) \
33 	static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_RO(name)
34 #define XFS_SYSFS_ATTR_WO(name) \
35 	static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_WO(name)
36 
37 #define ATTR_LIST(name) &xfs_sysfs_attr_##name.attr
38 
39 STATIC ssize_t
40 xfs_sysfs_object_show(
41 	struct kobject		*kobject,
42 	struct attribute	*attr,
43 	char			*buf)
44 {
45 	struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
46 
47 	return xfs_attr->show ? xfs_attr->show(kobject, buf) : 0;
48 }
49 
50 STATIC ssize_t
51 xfs_sysfs_object_store(
52 	struct kobject		*kobject,
53 	struct attribute	*attr,
54 	const char		*buf,
55 	size_t			count)
56 {
57 	struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
58 
59 	return xfs_attr->store ? xfs_attr->store(kobject, buf, count) : 0;
60 }
61 
62 static const struct sysfs_ops xfs_sysfs_ops = {
63 	.show = xfs_sysfs_object_show,
64 	.store = xfs_sysfs_object_store,
65 };
66 
67 static struct attribute *xfs_mp_attrs[] = {
68 	NULL,
69 };
70 ATTRIBUTE_GROUPS(xfs_mp);
71 
72 const struct kobj_type xfs_mp_ktype = {
73 	.release = xfs_sysfs_release,
74 	.sysfs_ops = &xfs_sysfs_ops,
75 	.default_groups = xfs_mp_groups,
76 };
77 
78 #ifdef DEBUG
79 /* debug */
80 
81 STATIC ssize_t
82 bug_on_assert_store(
83 	struct kobject		*kobject,
84 	const char		*buf,
85 	size_t			count)
86 {
87 	int			ret;
88 	int			val;
89 
90 	ret = kstrtoint(buf, 0, &val);
91 	if (ret)
92 		return ret;
93 
94 	if (val == 1)
95 		xfs_globals.bug_on_assert = true;
96 	else if (val == 0)
97 		xfs_globals.bug_on_assert = false;
98 	else
99 		return -EINVAL;
100 
101 	return count;
102 }
103 
104 STATIC ssize_t
105 bug_on_assert_show(
106 	struct kobject		*kobject,
107 	char			*buf)
108 {
109 	return sysfs_emit(buf, "%d\n", xfs_globals.bug_on_assert);
110 }
111 XFS_SYSFS_ATTR_RW(bug_on_assert);
112 
113 STATIC ssize_t
114 log_recovery_delay_store(
115 	struct kobject	*kobject,
116 	const char	*buf,
117 	size_t		count)
118 {
119 	int		ret;
120 	int		val;
121 
122 	ret = kstrtoint(buf, 0, &val);
123 	if (ret)
124 		return ret;
125 
126 	if (val < 0 || val > 60)
127 		return -EINVAL;
128 
129 	xfs_globals.log_recovery_delay = val;
130 
131 	return count;
132 }
133 
134 STATIC ssize_t
135 log_recovery_delay_show(
136 	struct kobject	*kobject,
137 	char		*buf)
138 {
139 	return sysfs_emit(buf, "%d\n", xfs_globals.log_recovery_delay);
140 }
141 XFS_SYSFS_ATTR_RW(log_recovery_delay);
142 
143 STATIC ssize_t
144 mount_delay_store(
145 	struct kobject	*kobject,
146 	const char	*buf,
147 	size_t		count)
148 {
149 	int		ret;
150 	int		val;
151 
152 	ret = kstrtoint(buf, 0, &val);
153 	if (ret)
154 		return ret;
155 
156 	if (val < 0 || val > 60)
157 		return -EINVAL;
158 
159 	xfs_globals.mount_delay = val;
160 
161 	return count;
162 }
163 
164 STATIC ssize_t
165 mount_delay_show(
166 	struct kobject	*kobject,
167 	char		*buf)
168 {
169 	return sysfs_emit(buf, "%d\n", xfs_globals.mount_delay);
170 }
171 XFS_SYSFS_ATTR_RW(mount_delay);
172 
173 static ssize_t
174 always_cow_store(
175 	struct kobject	*kobject,
176 	const char	*buf,
177 	size_t		count)
178 {
179 	ssize_t		ret;
180 
181 	ret = kstrtobool(buf, &xfs_globals.always_cow);
182 	if (ret < 0)
183 		return ret;
184 	return count;
185 }
186 
187 static ssize_t
188 always_cow_show(
189 	struct kobject	*kobject,
190 	char		*buf)
191 {
192 	return sysfs_emit(buf, "%d\n", xfs_globals.always_cow);
193 }
194 XFS_SYSFS_ATTR_RW(always_cow);
195 
196 /*
197  * Override how many threads the parallel work queue is allowed to create.
198  * This has to be a debug-only global (instead of an errortag) because one of
199  * the main users of parallel workqueues is mount time quotacheck.
200  */
201 STATIC ssize_t
202 pwork_threads_store(
203 	struct kobject	*kobject,
204 	const char	*buf,
205 	size_t		count)
206 {
207 	int		ret;
208 	int		val;
209 
210 	ret = kstrtoint(buf, 0, &val);
211 	if (ret)
212 		return ret;
213 
214 	if (val < -1 || val > num_possible_cpus())
215 		return -EINVAL;
216 
217 	xfs_globals.pwork_threads = val;
218 
219 	return count;
220 }
221 
222 STATIC ssize_t
223 pwork_threads_show(
224 	struct kobject	*kobject,
225 	char		*buf)
226 {
227 	return sysfs_emit(buf, "%d\n", xfs_globals.pwork_threads);
228 }
229 XFS_SYSFS_ATTR_RW(pwork_threads);
230 
231 /*
232  * The "LARP" (Logged extended Attribute Recovery Persistence) debugging knob
233  * sets the XFS_DA_OP_LOGGED flag on all xfs_attr_set operations performed on
234  * V5 filesystems.  As a result, the intermediate progress of all setxattr and
235  * removexattr operations are tracked via the log and can be restarted during
236  * recovery.  This is useful for testing xattr recovery prior to merging of the
237  * parent pointer feature which requires it to maintain consistency, and may be
238  * enabled for userspace xattrs in the future.
239  */
240 static ssize_t
241 larp_store(
242 	struct kobject	*kobject,
243 	const char	*buf,
244 	size_t		count)
245 {
246 	ssize_t		ret;
247 
248 	ret = kstrtobool(buf, &xfs_globals.larp);
249 	if (ret < 0)
250 		return ret;
251 	return count;
252 }
253 
254 STATIC ssize_t
255 larp_show(
256 	struct kobject	*kobject,
257 	char		*buf)
258 {
259 	return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.larp);
260 }
261 XFS_SYSFS_ATTR_RW(larp);
262 
263 STATIC ssize_t
264 bload_leaf_slack_store(
265 	struct kobject	*kobject,
266 	const char	*buf,
267 	size_t		count)
268 {
269 	int		ret;
270 	int		val;
271 
272 	ret = kstrtoint(buf, 0, &val);
273 	if (ret)
274 		return ret;
275 
276 	xfs_globals.bload_leaf_slack = val;
277 	return count;
278 }
279 
280 STATIC ssize_t
281 bload_leaf_slack_show(
282 	struct kobject	*kobject,
283 	char		*buf)
284 {
285 	return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.bload_leaf_slack);
286 }
287 XFS_SYSFS_ATTR_RW(bload_leaf_slack);
288 
289 STATIC ssize_t
290 bload_node_slack_store(
291 	struct kobject	*kobject,
292 	const char	*buf,
293 	size_t		count)
294 {
295 	int		ret;
296 	int		val;
297 
298 	ret = kstrtoint(buf, 0, &val);
299 	if (ret)
300 		return ret;
301 
302 	xfs_globals.bload_node_slack = val;
303 	return count;
304 }
305 
306 STATIC ssize_t
307 bload_node_slack_show(
308 	struct kobject	*kobject,
309 	char		*buf)
310 {
311 	return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.bload_node_slack);
312 }
313 XFS_SYSFS_ATTR_RW(bload_node_slack);
314 
315 static struct attribute *xfs_dbg_attrs[] = {
316 	ATTR_LIST(bug_on_assert),
317 	ATTR_LIST(log_recovery_delay),
318 	ATTR_LIST(mount_delay),
319 	ATTR_LIST(always_cow),
320 	ATTR_LIST(pwork_threads),
321 	ATTR_LIST(larp),
322 	ATTR_LIST(bload_leaf_slack),
323 	ATTR_LIST(bload_node_slack),
324 	NULL,
325 };
326 ATTRIBUTE_GROUPS(xfs_dbg);
327 
328 const struct kobj_type xfs_dbg_ktype = {
329 	.release = xfs_sysfs_release,
330 	.sysfs_ops = &xfs_sysfs_ops,
331 	.default_groups = xfs_dbg_groups,
332 };
333 
334 #endif /* DEBUG */
335 
336 /* stats */
337 
338 static inline struct xstats *
339 to_xstats(struct kobject *kobject)
340 {
341 	struct xfs_kobj *kobj = to_kobj(kobject);
342 
343 	return container_of(kobj, struct xstats, xs_kobj);
344 }
345 
346 STATIC ssize_t
347 stats_show(
348 	struct kobject	*kobject,
349 	char		*buf)
350 {
351 	struct xstats	*stats = to_xstats(kobject);
352 
353 	return xfs_stats_format(stats->xs_stats, buf);
354 }
355 XFS_SYSFS_ATTR_RO(stats);
356 
357 STATIC ssize_t
358 stats_clear_store(
359 	struct kobject	*kobject,
360 	const char	*buf,
361 	size_t		count)
362 {
363 	int		ret;
364 	int		val;
365 	struct xstats	*stats = to_xstats(kobject);
366 
367 	ret = kstrtoint(buf, 0, &val);
368 	if (ret)
369 		return ret;
370 
371 	if (val != 1)
372 		return -EINVAL;
373 
374 	xfs_stats_clearall(stats->xs_stats);
375 	return count;
376 }
377 XFS_SYSFS_ATTR_WO(stats_clear);
378 
379 static struct attribute *xfs_stats_attrs[] = {
380 	ATTR_LIST(stats),
381 	ATTR_LIST(stats_clear),
382 	NULL,
383 };
384 ATTRIBUTE_GROUPS(xfs_stats);
385 
386 const struct kobj_type xfs_stats_ktype = {
387 	.release = xfs_sysfs_release,
388 	.sysfs_ops = &xfs_sysfs_ops,
389 	.default_groups = xfs_stats_groups,
390 };
391 
392 /* xlog */
393 
394 static inline struct xlog *
395 to_xlog(struct kobject *kobject)
396 {
397 	struct xfs_kobj *kobj = to_kobj(kobject);
398 
399 	return container_of(kobj, struct xlog, l_kobj);
400 }
401 
402 STATIC ssize_t
403 log_head_lsn_show(
404 	struct kobject	*kobject,
405 	char		*buf)
406 {
407 	int cycle;
408 	int block;
409 	struct xlog *log = to_xlog(kobject);
410 
411 	spin_lock(&log->l_icloglock);
412 	cycle = log->l_curr_cycle;
413 	block = log->l_curr_block;
414 	spin_unlock(&log->l_icloglock);
415 
416 	return sysfs_emit(buf, "%d:%d\n", cycle, block);
417 }
418 XFS_SYSFS_ATTR_RO(log_head_lsn);
419 
420 STATIC ssize_t
421 log_tail_lsn_show(
422 	struct kobject	*kobject,
423 	char		*buf)
424 {
425 	int cycle;
426 	int block;
427 	struct xlog *log = to_xlog(kobject);
428 
429 	xlog_crack_atomic_lsn(&log->l_tail_lsn, &cycle, &block);
430 	return sysfs_emit(buf, "%d:%d\n", cycle, block);
431 }
432 XFS_SYSFS_ATTR_RO(log_tail_lsn);
433 
434 STATIC ssize_t
435 reserve_grant_head_show(
436 	struct kobject	*kobject,
437 	char		*buf)
438 
439 {
440 	int cycle;
441 	int bytes;
442 	struct xlog *log = to_xlog(kobject);
443 
444 	xlog_crack_grant_head(&log->l_reserve_head.grant, &cycle, &bytes);
445 	return sysfs_emit(buf, "%d:%d\n", cycle, bytes);
446 }
447 XFS_SYSFS_ATTR_RO(reserve_grant_head);
448 
449 STATIC ssize_t
450 write_grant_head_show(
451 	struct kobject	*kobject,
452 	char		*buf)
453 {
454 	int cycle;
455 	int bytes;
456 	struct xlog *log = to_xlog(kobject);
457 
458 	xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &bytes);
459 	return sysfs_emit(buf, "%d:%d\n", cycle, bytes);
460 }
461 XFS_SYSFS_ATTR_RO(write_grant_head);
462 
463 static struct attribute *xfs_log_attrs[] = {
464 	ATTR_LIST(log_head_lsn),
465 	ATTR_LIST(log_tail_lsn),
466 	ATTR_LIST(reserve_grant_head),
467 	ATTR_LIST(write_grant_head),
468 	NULL,
469 };
470 ATTRIBUTE_GROUPS(xfs_log);
471 
472 const struct kobj_type xfs_log_ktype = {
473 	.release = xfs_sysfs_release,
474 	.sysfs_ops = &xfs_sysfs_ops,
475 	.default_groups = xfs_log_groups,
476 };
477 
478 /*
479  * Metadata IO error configuration
480  *
481  * The sysfs structure here is:
482  *	...xfs/<dev>/error/<class>/<errno>/<error_attrs>
483  *
484  * where <class> allows us to discriminate between data IO and metadata IO,
485  * and any other future type of IO (e.g. special inode or directory error
486  * handling) we care to support.
487  */
488 static inline struct xfs_error_cfg *
489 to_error_cfg(struct kobject *kobject)
490 {
491 	struct xfs_kobj *kobj = to_kobj(kobject);
492 	return container_of(kobj, struct xfs_error_cfg, kobj);
493 }
494 
495 static inline struct xfs_mount *
496 err_to_mp(struct kobject *kobject)
497 {
498 	struct xfs_kobj *kobj = to_kobj(kobject);
499 	return container_of(kobj, struct xfs_mount, m_error_kobj);
500 }
501 
502 static ssize_t
503 max_retries_show(
504 	struct kobject	*kobject,
505 	char		*buf)
506 {
507 	int		retries;
508 	struct xfs_error_cfg *cfg = to_error_cfg(kobject);
509 
510 	if (cfg->max_retries == XFS_ERR_RETRY_FOREVER)
511 		retries = -1;
512 	else
513 		retries = cfg->max_retries;
514 
515 	return sysfs_emit(buf, "%d\n", retries);
516 }
517 
518 static ssize_t
519 max_retries_store(
520 	struct kobject	*kobject,
521 	const char	*buf,
522 	size_t		count)
523 {
524 	struct xfs_error_cfg *cfg = to_error_cfg(kobject);
525 	int		ret;
526 	int		val;
527 
528 	ret = kstrtoint(buf, 0, &val);
529 	if (ret)
530 		return ret;
531 
532 	if (val < -1)
533 		return -EINVAL;
534 
535 	if (val == -1)
536 		cfg->max_retries = XFS_ERR_RETRY_FOREVER;
537 	else
538 		cfg->max_retries = val;
539 	return count;
540 }
541 XFS_SYSFS_ATTR_RW(max_retries);
542 
543 static ssize_t
544 retry_timeout_seconds_show(
545 	struct kobject	*kobject,
546 	char		*buf)
547 {
548 	int		timeout;
549 	struct xfs_error_cfg *cfg = to_error_cfg(kobject);
550 
551 	if (cfg->retry_timeout == XFS_ERR_RETRY_FOREVER)
552 		timeout = -1;
553 	else
554 		timeout = jiffies_to_msecs(cfg->retry_timeout) / MSEC_PER_SEC;
555 
556 	return sysfs_emit(buf, "%d\n", timeout);
557 }
558 
559 static ssize_t
560 retry_timeout_seconds_store(
561 	struct kobject	*kobject,
562 	const char	*buf,
563 	size_t		count)
564 {
565 	struct xfs_error_cfg *cfg = to_error_cfg(kobject);
566 	int		ret;
567 	int		val;
568 
569 	ret = kstrtoint(buf, 0, &val);
570 	if (ret)
571 		return ret;
572 
573 	/* 1 day timeout maximum, -1 means infinite */
574 	if (val < -1 || val > 86400)
575 		return -EINVAL;
576 
577 	if (val == -1)
578 		cfg->retry_timeout = XFS_ERR_RETRY_FOREVER;
579 	else {
580 		cfg->retry_timeout = msecs_to_jiffies(val * MSEC_PER_SEC);
581 		ASSERT(msecs_to_jiffies(val * MSEC_PER_SEC) < LONG_MAX);
582 	}
583 	return count;
584 }
585 XFS_SYSFS_ATTR_RW(retry_timeout_seconds);
586 
587 static ssize_t
588 fail_at_unmount_show(
589 	struct kobject	*kobject,
590 	char		*buf)
591 {
592 	struct xfs_mount	*mp = err_to_mp(kobject);
593 
594 	return sysfs_emit(buf, "%d\n", mp->m_fail_unmount);
595 }
596 
597 static ssize_t
598 fail_at_unmount_store(
599 	struct kobject	*kobject,
600 	const char	*buf,
601 	size_t		count)
602 {
603 	struct xfs_mount	*mp = err_to_mp(kobject);
604 	int		ret;
605 	int		val;
606 
607 	ret = kstrtoint(buf, 0, &val);
608 	if (ret)
609 		return ret;
610 
611 	if (val < 0 || val > 1)
612 		return -EINVAL;
613 
614 	mp->m_fail_unmount = val;
615 	return count;
616 }
617 XFS_SYSFS_ATTR_RW(fail_at_unmount);
618 
619 static struct attribute *xfs_error_attrs[] = {
620 	ATTR_LIST(max_retries),
621 	ATTR_LIST(retry_timeout_seconds),
622 	NULL,
623 };
624 ATTRIBUTE_GROUPS(xfs_error);
625 
626 static const struct kobj_type xfs_error_cfg_ktype = {
627 	.release = xfs_sysfs_release,
628 	.sysfs_ops = &xfs_sysfs_ops,
629 	.default_groups = xfs_error_groups,
630 };
631 
632 static const struct kobj_type xfs_error_ktype = {
633 	.release = xfs_sysfs_release,
634 	.sysfs_ops = &xfs_sysfs_ops,
635 };
636 
637 /*
638  * Error initialization tables. These need to be ordered in the same
639  * order as the enums used to index the array. All class init tables need to
640  * define a "default" behaviour as the first entry, all other entries can be
641  * empty.
642  */
643 struct xfs_error_init {
644 	char		*name;
645 	int		max_retries;
646 	int		retry_timeout;	/* in seconds */
647 };
648 
649 static const struct xfs_error_init xfs_error_meta_init[XFS_ERR_ERRNO_MAX] = {
650 	{ .name = "default",
651 	  .max_retries = XFS_ERR_RETRY_FOREVER,
652 	  .retry_timeout = XFS_ERR_RETRY_FOREVER,
653 	},
654 	{ .name = "EIO",
655 	  .max_retries = XFS_ERR_RETRY_FOREVER,
656 	  .retry_timeout = XFS_ERR_RETRY_FOREVER,
657 	},
658 	{ .name = "ENOSPC",
659 	  .max_retries = XFS_ERR_RETRY_FOREVER,
660 	  .retry_timeout = XFS_ERR_RETRY_FOREVER,
661 	},
662 	{ .name = "ENODEV",
663 	  .max_retries = 0,	/* We can't recover from devices disappearing */
664 	  .retry_timeout = 0,
665 	},
666 };
667 
668 static int
669 xfs_error_sysfs_init_class(
670 	struct xfs_mount	*mp,
671 	int			class,
672 	const char		*parent_name,
673 	struct xfs_kobj		*parent_kobj,
674 	const struct xfs_error_init init[])
675 {
676 	struct xfs_error_cfg	*cfg;
677 	int			error;
678 	int			i;
679 
680 	ASSERT(class < XFS_ERR_CLASS_MAX);
681 
682 	error = xfs_sysfs_init(parent_kobj, &xfs_error_ktype,
683 				&mp->m_error_kobj, parent_name);
684 	if (error)
685 		return error;
686 
687 	for (i = 0; i < XFS_ERR_ERRNO_MAX; i++) {
688 		cfg = &mp->m_error_cfg[class][i];
689 		error = xfs_sysfs_init(&cfg->kobj, &xfs_error_cfg_ktype,
690 					parent_kobj, init[i].name);
691 		if (error)
692 			goto out_error;
693 
694 		cfg->max_retries = init[i].max_retries;
695 		if (init[i].retry_timeout == XFS_ERR_RETRY_FOREVER)
696 			cfg->retry_timeout = XFS_ERR_RETRY_FOREVER;
697 		else
698 			cfg->retry_timeout = msecs_to_jiffies(
699 					init[i].retry_timeout * MSEC_PER_SEC);
700 	}
701 	return 0;
702 
703 out_error:
704 	/* unwind the entries that succeeded */
705 	for (i--; i >= 0; i--) {
706 		cfg = &mp->m_error_cfg[class][i];
707 		xfs_sysfs_del(&cfg->kobj);
708 	}
709 	xfs_sysfs_del(parent_kobj);
710 	return error;
711 }
712 
713 int
714 xfs_error_sysfs_init(
715 	struct xfs_mount	*mp)
716 {
717 	int			error;
718 
719 	/* .../xfs/<dev>/error/ */
720 	error = xfs_sysfs_init(&mp->m_error_kobj, &xfs_error_ktype,
721 				&mp->m_kobj, "error");
722 	if (error)
723 		return error;
724 
725 	error = sysfs_create_file(&mp->m_error_kobj.kobject,
726 				  ATTR_LIST(fail_at_unmount));
727 
728 	if (error)
729 		goto out_error;
730 
731 	/* .../xfs/<dev>/error/metadata/ */
732 	error = xfs_error_sysfs_init_class(mp, XFS_ERR_METADATA,
733 				"metadata", &mp->m_error_meta_kobj,
734 				xfs_error_meta_init);
735 	if (error)
736 		goto out_error;
737 
738 	return 0;
739 
740 out_error:
741 	xfs_sysfs_del(&mp->m_error_kobj);
742 	return error;
743 }
744 
745 void
746 xfs_error_sysfs_del(
747 	struct xfs_mount	*mp)
748 {
749 	struct xfs_error_cfg	*cfg;
750 	int			i, j;
751 
752 	for (i = 0; i < XFS_ERR_CLASS_MAX; i++) {
753 		for (j = 0; j < XFS_ERR_ERRNO_MAX; j++) {
754 			cfg = &mp->m_error_cfg[i][j];
755 
756 			xfs_sysfs_del(&cfg->kobj);
757 		}
758 	}
759 	xfs_sysfs_del(&mp->m_error_meta_kobj);
760 	xfs_sysfs_del(&mp->m_error_kobj);
761 }
762 
763 struct xfs_error_cfg *
764 xfs_error_get_cfg(
765 	struct xfs_mount	*mp,
766 	int			error_class,
767 	int			error)
768 {
769 	struct xfs_error_cfg	*cfg;
770 
771 	if (error < 0)
772 		error = -error;
773 
774 	switch (error) {
775 	case EIO:
776 		cfg = &mp->m_error_cfg[error_class][XFS_ERR_EIO];
777 		break;
778 	case ENOSPC:
779 		cfg = &mp->m_error_cfg[error_class][XFS_ERR_ENOSPC];
780 		break;
781 	case ENODEV:
782 		cfg = &mp->m_error_cfg[error_class][XFS_ERR_ENODEV];
783 		break;
784 	default:
785 		cfg = &mp->m_error_cfg[error_class][XFS_ERR_DEFAULT];
786 		break;
787 	}
788 
789 	return cfg;
790 }
791