xref: /openbmc/linux/drivers/md/bcache/sysfs.c (revision d623f60d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * bcache sysfs interfaces
4  *
5  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6  * Copyright 2012 Google, Inc.
7  */
8 
9 #include "bcache.h"
10 #include "sysfs.h"
11 #include "btree.h"
12 #include "request.h"
13 #include "writeback.h"
14 
15 #include <linux/blkdev.h>
16 #include <linux/sort.h>
17 #include <linux/sched/clock.h>
18 
19 /* Default is -1; we skip past it for struct cached_dev's cache mode */
20 static const char * const bch_cache_modes[] = {
21 	"writethrough",
22 	"writeback",
23 	"writearound",
24 	"none",
25 	NULL
26 };
27 
28 /* Default is -1; we skip past it for stop_when_cache_set_failed */
29 static const char * const bch_stop_on_failure_modes[] = {
30 	"auto",
31 	"always",
32 	NULL
33 };
34 
35 static const char * const cache_replacement_policies[] = {
36 	"lru",
37 	"fifo",
38 	"random",
39 	NULL
40 };
41 
42 static const char * const error_actions[] = {
43 	"unregister",
44 	"panic",
45 	NULL
46 };
47 
48 write_attribute(attach);
49 write_attribute(detach);
50 write_attribute(unregister);
51 write_attribute(stop);
52 write_attribute(clear_stats);
53 write_attribute(trigger_gc);
54 write_attribute(prune_cache);
55 write_attribute(flash_vol_create);
56 
57 read_attribute(bucket_size);
58 read_attribute(block_size);
59 read_attribute(nbuckets);
60 read_attribute(tree_depth);
61 read_attribute(root_usage_percent);
62 read_attribute(priority_stats);
63 read_attribute(btree_cache_size);
64 read_attribute(btree_cache_max_chain);
65 read_attribute(cache_available_percent);
66 read_attribute(written);
67 read_attribute(btree_written);
68 read_attribute(metadata_written);
69 read_attribute(active_journal_entries);
70 
71 sysfs_time_stats_attribute(btree_gc,	sec, ms);
72 sysfs_time_stats_attribute(btree_split, sec, us);
73 sysfs_time_stats_attribute(btree_sort,	ms,  us);
74 sysfs_time_stats_attribute(btree_read,	ms,  us);
75 
76 read_attribute(btree_nodes);
77 read_attribute(btree_used_percent);
78 read_attribute(average_key_size);
79 read_attribute(dirty_data);
80 read_attribute(bset_tree_stats);
81 
82 read_attribute(state);
83 read_attribute(cache_read_races);
84 read_attribute(reclaim);
85 read_attribute(flush_write);
86 read_attribute(retry_flush_write);
87 read_attribute(writeback_keys_done);
88 read_attribute(writeback_keys_failed);
89 read_attribute(io_errors);
90 read_attribute(congested);
91 rw_attribute(congested_read_threshold_us);
92 rw_attribute(congested_write_threshold_us);
93 
94 rw_attribute(sequential_cutoff);
95 rw_attribute(data_csum);
96 rw_attribute(cache_mode);
97 rw_attribute(stop_when_cache_set_failed);
98 rw_attribute(writeback_metadata);
99 rw_attribute(writeback_running);
100 rw_attribute(writeback_percent);
101 rw_attribute(writeback_delay);
102 rw_attribute(writeback_rate);
103 
104 rw_attribute(writeback_rate_update_seconds);
105 rw_attribute(writeback_rate_i_term_inverse);
106 rw_attribute(writeback_rate_p_term_inverse);
107 rw_attribute(writeback_rate_minimum);
108 read_attribute(writeback_rate_debug);
109 
110 read_attribute(stripe_size);
111 read_attribute(partial_stripes_expensive);
112 
113 rw_attribute(synchronous);
114 rw_attribute(journal_delay_ms);
115 rw_attribute(io_disable);
116 rw_attribute(discard);
117 rw_attribute(running);
118 rw_attribute(label);
119 rw_attribute(readahead);
120 rw_attribute(errors);
121 rw_attribute(io_error_limit);
122 rw_attribute(io_error_halflife);
123 rw_attribute(verify);
124 rw_attribute(bypass_torture_test);
125 rw_attribute(key_merging_disabled);
126 rw_attribute(gc_always_rewrite);
127 rw_attribute(expensive_debug_checks);
128 rw_attribute(cache_replacement_policy);
129 rw_attribute(btree_shrinker_disabled);
130 rw_attribute(copy_gc_enabled);
131 rw_attribute(size);
132 
133 static ssize_t bch_snprint_string_list(char *buf, size_t size, const char * const list[],
134 			    size_t selected)
135 {
136 	char *out = buf;
137 	size_t i;
138 
139 	for (i = 0; list[i]; i++)
140 		out += snprintf(out, buf + size - out,
141 				i == selected ? "[%s] " : "%s ", list[i]);
142 
143 	out[-1] = '\n';
144 	return out - buf;
145 }
146 
147 SHOW(__bch_cached_dev)
148 {
149 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
150 					     disk.kobj);
151 	const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
152 
153 #define var(stat)		(dc->stat)
154 
155 	if (attr == &sysfs_cache_mode)
156 		return bch_snprint_string_list(buf, PAGE_SIZE,
157 					       bch_cache_modes,
158 					       BDEV_CACHE_MODE(&dc->sb));
159 
160 	if (attr == &sysfs_stop_when_cache_set_failed)
161 		return bch_snprint_string_list(buf, PAGE_SIZE,
162 					       bch_stop_on_failure_modes,
163 					       dc->stop_when_cache_set_failed);
164 
165 
166 	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
167 	var_printf(verify,		"%i");
168 	var_printf(bypass_torture_test,	"%i");
169 	var_printf(writeback_metadata,	"%i");
170 	var_printf(writeback_running,	"%i");
171 	var_print(writeback_delay);
172 	var_print(writeback_percent);
173 	sysfs_hprint(writeback_rate,	dc->writeback_rate.rate << 9);
174 	sysfs_hprint(io_errors,		atomic_read(&dc->io_errors));
175 	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
176 	sysfs_printf(io_disable,	"%i", dc->io_disable);
177 	var_print(writeback_rate_update_seconds);
178 	var_print(writeback_rate_i_term_inverse);
179 	var_print(writeback_rate_p_term_inverse);
180 	var_print(writeback_rate_minimum);
181 
182 	if (attr == &sysfs_writeback_rate_debug) {
183 		char rate[20];
184 		char dirty[20];
185 		char target[20];
186 		char proportional[20];
187 		char integral[20];
188 		char change[20];
189 		s64 next_io;
190 
191 		bch_hprint(rate,	dc->writeback_rate.rate << 9);
192 		bch_hprint(dirty,	bcache_dev_sectors_dirty(&dc->disk) << 9);
193 		bch_hprint(target,	dc->writeback_rate_target << 9);
194 		bch_hprint(proportional,dc->writeback_rate_proportional << 9);
195 		bch_hprint(integral,	dc->writeback_rate_integral_scaled << 9);
196 		bch_hprint(change,	dc->writeback_rate_change << 9);
197 
198 		next_io = div64_s64(dc->writeback_rate.next - local_clock(),
199 				    NSEC_PER_MSEC);
200 
201 		return sprintf(buf,
202 			       "rate:\t\t%s/sec\n"
203 			       "dirty:\t\t%s\n"
204 			       "target:\t\t%s\n"
205 			       "proportional:\t%s\n"
206 			       "integral:\t%s\n"
207 			       "change:\t\t%s/sec\n"
208 			       "next io:\t%llims\n",
209 			       rate, dirty, target, proportional,
210 			       integral, change, next_io);
211 	}
212 
213 	sysfs_hprint(dirty_data,
214 		     bcache_dev_sectors_dirty(&dc->disk) << 9);
215 
216 	sysfs_hprint(stripe_size,	 ((uint64_t)dc->disk.stripe_size) << 9);
217 	var_printf(partial_stripes_expensive,	"%u");
218 
219 	var_hprint(sequential_cutoff);
220 	var_hprint(readahead);
221 
222 	sysfs_print(running,		atomic_read(&dc->running));
223 	sysfs_print(state,		states[BDEV_STATE(&dc->sb)]);
224 
225 	if (attr == &sysfs_label) {
226 		memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
227 		buf[SB_LABEL_SIZE + 1] = '\0';
228 		strcat(buf, "\n");
229 		return strlen(buf);
230 	}
231 
232 #undef var
233 	return 0;
234 }
235 SHOW_LOCKED(bch_cached_dev)
236 
237 STORE(__cached_dev)
238 {
239 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
240 					     disk.kobj);
241 	ssize_t v;
242 	struct cache_set *c;
243 	struct kobj_uevent_env *env;
244 
245 #define d_strtoul(var)		sysfs_strtoul(var, dc->var)
246 #define d_strtoul_nonzero(var)	sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
247 #define d_strtoi_h(var)		sysfs_hatoi(var, dc->var)
248 
249 	sysfs_strtoul(data_csum,	dc->disk.data_csum);
250 	d_strtoul(verify);
251 	d_strtoul(bypass_torture_test);
252 	d_strtoul(writeback_metadata);
253 	d_strtoul(writeback_running);
254 	d_strtoul(writeback_delay);
255 
256 	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40);
257 
258 	sysfs_strtoul_clamp(writeback_rate,
259 			    dc->writeback_rate.rate, 1, INT_MAX);
260 
261 	sysfs_strtoul_clamp(writeback_rate_update_seconds,
262 			    dc->writeback_rate_update_seconds,
263 			    1, WRITEBACK_RATE_UPDATE_SECS_MAX);
264 	d_strtoul(writeback_rate_i_term_inverse);
265 	d_strtoul_nonzero(writeback_rate_p_term_inverse);
266 
267 	sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);
268 
269 	if (attr == &sysfs_io_disable) {
270 		int v = strtoul_or_return(buf);
271 
272 		dc->io_disable = v ? 1 : 0;
273 	}
274 
275 	d_strtoi_h(sequential_cutoff);
276 	d_strtoi_h(readahead);
277 
278 	if (attr == &sysfs_clear_stats)
279 		bch_cache_accounting_clear(&dc->accounting);
280 
281 	if (attr == &sysfs_running &&
282 	    strtoul_or_return(buf))
283 		bch_cached_dev_run(dc);
284 
285 	if (attr == &sysfs_cache_mode) {
286 		v = __sysfs_match_string(bch_cache_modes, -1, buf);
287 		if (v < 0)
288 			return v;
289 
290 		if ((unsigned) v != BDEV_CACHE_MODE(&dc->sb)) {
291 			SET_BDEV_CACHE_MODE(&dc->sb, v);
292 			bch_write_bdev_super(dc, NULL);
293 		}
294 	}
295 
296 	if (attr == &sysfs_stop_when_cache_set_failed) {
297 		v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
298 		if (v < 0)
299 			return v;
300 
301 		dc->stop_when_cache_set_failed = v;
302 	}
303 
304 	if (attr == &sysfs_label) {
305 		if (size > SB_LABEL_SIZE)
306 			return -EINVAL;
307 		memcpy(dc->sb.label, buf, size);
308 		if (size < SB_LABEL_SIZE)
309 			dc->sb.label[size] = '\0';
310 		if (size && dc->sb.label[size - 1] == '\n')
311 			dc->sb.label[size - 1] = '\0';
312 		bch_write_bdev_super(dc, NULL);
313 		if (dc->disk.c) {
314 			memcpy(dc->disk.c->uuids[dc->disk.id].label,
315 			       buf, SB_LABEL_SIZE);
316 			bch_uuid_write(dc->disk.c);
317 		}
318 		env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
319 		if (!env)
320 			return -ENOMEM;
321 		add_uevent_var(env, "DRIVER=bcache");
322 		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
323 		add_uevent_var(env, "CACHED_LABEL=%s", buf);
324 		kobject_uevent_env(
325 			&disk_to_dev(dc->disk.disk)->kobj, KOBJ_CHANGE, env->envp);
326 		kfree(env);
327 	}
328 
329 	if (attr == &sysfs_attach) {
330 		uint8_t		set_uuid[16];
331 
332 		if (bch_parse_uuid(buf, set_uuid) < 16)
333 			return -EINVAL;
334 
335 		v = -ENOENT;
336 		list_for_each_entry(c, &bch_cache_sets, list) {
337 			v = bch_cached_dev_attach(dc, c, set_uuid);
338 			if (!v)
339 				return size;
340 		}
341 
342 		pr_err("Can't attach %s: cache set not found", buf);
343 		return v;
344 	}
345 
346 	if (attr == &sysfs_detach && dc->disk.c)
347 		bch_cached_dev_detach(dc);
348 
349 	if (attr == &sysfs_stop)
350 		bcache_device_stop(&dc->disk);
351 
352 	return size;
353 }
354 
355 STORE(bch_cached_dev)
356 {
357 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
358 					     disk.kobj);
359 
360 	mutex_lock(&bch_register_lock);
361 	size = __cached_dev_store(kobj, attr, buf, size);
362 
363 	if (attr == &sysfs_writeback_running)
364 		bch_writeback_queue(dc);
365 
366 	if (attr == &sysfs_writeback_percent)
367 		if (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags))
368 			schedule_delayed_work(&dc->writeback_rate_update,
369 				      dc->writeback_rate_update_seconds * HZ);
370 
371 	mutex_unlock(&bch_register_lock);
372 	return size;
373 }
374 
375 static struct attribute *bch_cached_dev_files[] = {
376 	&sysfs_attach,
377 	&sysfs_detach,
378 	&sysfs_stop,
379 #if 0
380 	&sysfs_data_csum,
381 #endif
382 	&sysfs_cache_mode,
383 	&sysfs_stop_when_cache_set_failed,
384 	&sysfs_writeback_metadata,
385 	&sysfs_writeback_running,
386 	&sysfs_writeback_delay,
387 	&sysfs_writeback_percent,
388 	&sysfs_writeback_rate,
389 	&sysfs_writeback_rate_update_seconds,
390 	&sysfs_writeback_rate_i_term_inverse,
391 	&sysfs_writeback_rate_p_term_inverse,
392 	&sysfs_writeback_rate_debug,
393 	&sysfs_errors,
394 	&sysfs_io_error_limit,
395 	&sysfs_io_disable,
396 	&sysfs_dirty_data,
397 	&sysfs_stripe_size,
398 	&sysfs_partial_stripes_expensive,
399 	&sysfs_sequential_cutoff,
400 	&sysfs_clear_stats,
401 	&sysfs_running,
402 	&sysfs_state,
403 	&sysfs_label,
404 	&sysfs_readahead,
405 #ifdef CONFIG_BCACHE_DEBUG
406 	&sysfs_verify,
407 	&sysfs_bypass_torture_test,
408 #endif
409 	NULL
410 };
411 KTYPE(bch_cached_dev);
412 
413 SHOW(bch_flash_dev)
414 {
415 	struct bcache_device *d = container_of(kobj, struct bcache_device,
416 					       kobj);
417 	struct uuid_entry *u = &d->c->uuids[d->id];
418 
419 	sysfs_printf(data_csum,	"%i", d->data_csum);
420 	sysfs_hprint(size,	u->sectors << 9);
421 
422 	if (attr == &sysfs_label) {
423 		memcpy(buf, u->label, SB_LABEL_SIZE);
424 		buf[SB_LABEL_SIZE + 1] = '\0';
425 		strcat(buf, "\n");
426 		return strlen(buf);
427 	}
428 
429 	return 0;
430 }
431 
432 STORE(__bch_flash_dev)
433 {
434 	struct bcache_device *d = container_of(kobj, struct bcache_device,
435 					       kobj);
436 	struct uuid_entry *u = &d->c->uuids[d->id];
437 
438 	sysfs_strtoul(data_csum,	d->data_csum);
439 
440 	if (attr == &sysfs_size) {
441 		uint64_t v;
442 		strtoi_h_or_return(buf, v);
443 
444 		u->sectors = v >> 9;
445 		bch_uuid_write(d->c);
446 		set_capacity(d->disk, u->sectors);
447 	}
448 
449 	if (attr == &sysfs_label) {
450 		memcpy(u->label, buf, SB_LABEL_SIZE);
451 		bch_uuid_write(d->c);
452 	}
453 
454 	if (attr == &sysfs_unregister) {
455 		set_bit(BCACHE_DEV_DETACHING, &d->flags);
456 		bcache_device_stop(d);
457 	}
458 
459 	return size;
460 }
461 STORE_LOCKED(bch_flash_dev)
462 
463 static struct attribute *bch_flash_dev_files[] = {
464 	&sysfs_unregister,
465 #if 0
466 	&sysfs_data_csum,
467 #endif
468 	&sysfs_label,
469 	&sysfs_size,
470 	NULL
471 };
472 KTYPE(bch_flash_dev);
473 
474 struct bset_stats_op {
475 	struct btree_op op;
476 	size_t nodes;
477 	struct bset_stats stats;
478 };
479 
480 static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b)
481 {
482 	struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op);
483 
484 	op->nodes++;
485 	bch_btree_keys_stats(&b->keys, &op->stats);
486 
487 	return MAP_CONTINUE;
488 }
489 
490 static int bch_bset_print_stats(struct cache_set *c, char *buf)
491 {
492 	struct bset_stats_op op;
493 	int ret;
494 
495 	memset(&op, 0, sizeof(op));
496 	bch_btree_op_init(&op.op, -1);
497 
498 	ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats);
499 	if (ret < 0)
500 		return ret;
501 
502 	return snprintf(buf, PAGE_SIZE,
503 			"btree nodes:		%zu\n"
504 			"written sets:		%zu\n"
505 			"unwritten sets:		%zu\n"
506 			"written key bytes:	%zu\n"
507 			"unwritten key bytes:	%zu\n"
508 			"floats:			%zu\n"
509 			"failed:			%zu\n",
510 			op.nodes,
511 			op.stats.sets_written, op.stats.sets_unwritten,
512 			op.stats.bytes_written, op.stats.bytes_unwritten,
513 			op.stats.floats, op.stats.failed);
514 }
515 
516 static unsigned bch_root_usage(struct cache_set *c)
517 {
518 	unsigned bytes = 0;
519 	struct bkey *k;
520 	struct btree *b;
521 	struct btree_iter iter;
522 
523 	goto lock_root;
524 
525 	do {
526 		rw_unlock(false, b);
527 lock_root:
528 		b = c->root;
529 		rw_lock(false, b, b->level);
530 	} while (b != c->root);
531 
532 	for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
533 		bytes += bkey_bytes(k);
534 
535 	rw_unlock(false, b);
536 
537 	return (bytes * 100) / btree_bytes(c);
538 }
539 
540 static size_t bch_cache_size(struct cache_set *c)
541 {
542 	size_t ret = 0;
543 	struct btree *b;
544 
545 	mutex_lock(&c->bucket_lock);
546 	list_for_each_entry(b, &c->btree_cache, list)
547 		ret += 1 << (b->keys.page_order + PAGE_SHIFT);
548 
549 	mutex_unlock(&c->bucket_lock);
550 	return ret;
551 }
552 
553 static unsigned bch_cache_max_chain(struct cache_set *c)
554 {
555 	unsigned ret = 0;
556 	struct hlist_head *h;
557 
558 	mutex_lock(&c->bucket_lock);
559 
560 	for (h = c->bucket_hash;
561 	     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
562 	     h++) {
563 		unsigned i = 0;
564 		struct hlist_node *p;
565 
566 		hlist_for_each(p, h)
567 			i++;
568 
569 		ret = max(ret, i);
570 	}
571 
572 	mutex_unlock(&c->bucket_lock);
573 	return ret;
574 }
575 
576 static unsigned bch_btree_used(struct cache_set *c)
577 {
578 	return div64_u64(c->gc_stats.key_bytes * 100,
579 			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
580 }
581 
582 static unsigned bch_average_key_size(struct cache_set *c)
583 {
584 	return c->gc_stats.nkeys
585 		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
586 		: 0;
587 }
588 
589 SHOW(__bch_cache_set)
590 {
591 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
592 
593 	sysfs_print(synchronous,		CACHE_SYNC(&c->sb));
594 	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
595 	sysfs_hprint(bucket_size,		bucket_bytes(c));
596 	sysfs_hprint(block_size,		block_bytes(c));
597 	sysfs_print(tree_depth,			c->root->level);
598 	sysfs_print(root_usage_percent,		bch_root_usage(c));
599 
600 	sysfs_hprint(btree_cache_size,		bch_cache_size(c));
601 	sysfs_print(btree_cache_max_chain,	bch_cache_max_chain(c));
602 	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
603 
604 	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
605 	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
606 	sysfs_print_time_stats(&c->sort.time,		btree_sort, ms, us);
607 	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
608 
609 	sysfs_print(btree_used_percent,	bch_btree_used(c));
610 	sysfs_print(btree_nodes,	c->gc_stats.nodes);
611 	sysfs_hprint(average_key_size,	bch_average_key_size(c));
612 
613 	sysfs_print(cache_read_races,
614 		    atomic_long_read(&c->cache_read_races));
615 
616 	sysfs_print(reclaim,
617 		    atomic_long_read(&c->reclaim));
618 
619 	sysfs_print(flush_write,
620 		    atomic_long_read(&c->flush_write));
621 
622 	sysfs_print(retry_flush_write,
623 		    atomic_long_read(&c->retry_flush_write));
624 
625 	sysfs_print(writeback_keys_done,
626 		    atomic_long_read(&c->writeback_keys_done));
627 	sysfs_print(writeback_keys_failed,
628 		    atomic_long_read(&c->writeback_keys_failed));
629 
630 	if (attr == &sysfs_errors)
631 		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
632 					       c->on_error);
633 
634 	/* See count_io_errors for why 88 */
635 	sysfs_print(io_error_halflife,	c->error_decay * 88);
636 	sysfs_print(io_error_limit,	c->error_limit);
637 
638 	sysfs_hprint(congested,
639 		     ((uint64_t) bch_get_congested(c)) << 9);
640 	sysfs_print(congested_read_threshold_us,
641 		    c->congested_read_threshold_us);
642 	sysfs_print(congested_write_threshold_us,
643 		    c->congested_write_threshold_us);
644 
645 	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
646 	sysfs_printf(verify,			"%i", c->verify);
647 	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
648 	sysfs_printf(expensive_debug_checks,
649 		     "%i", c->expensive_debug_checks);
650 	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
651 	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
652 	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
653 	sysfs_printf(io_disable,		"%i",
654 		     test_bit(CACHE_SET_IO_DISABLE, &c->flags));
655 
656 	if (attr == &sysfs_bset_tree_stats)
657 		return bch_bset_print_stats(c, buf);
658 
659 	return 0;
660 }
661 SHOW_LOCKED(bch_cache_set)
662 
663 STORE(__bch_cache_set)
664 {
665 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
666 	ssize_t v;
667 
668 	if (attr == &sysfs_unregister)
669 		bch_cache_set_unregister(c);
670 
671 	if (attr == &sysfs_stop)
672 		bch_cache_set_stop(c);
673 
674 	if (attr == &sysfs_synchronous) {
675 		bool sync = strtoul_or_return(buf);
676 
677 		if (sync != CACHE_SYNC(&c->sb)) {
678 			SET_CACHE_SYNC(&c->sb, sync);
679 			bcache_write_super(c);
680 		}
681 	}
682 
683 	if (attr == &sysfs_flash_vol_create) {
684 		int r;
685 		uint64_t v;
686 		strtoi_h_or_return(buf, v);
687 
688 		r = bch_flash_dev_create(c, v);
689 		if (r)
690 			return r;
691 	}
692 
693 	if (attr == &sysfs_clear_stats) {
694 		atomic_long_set(&c->writeback_keys_done,	0);
695 		atomic_long_set(&c->writeback_keys_failed,	0);
696 
697 		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
698 		bch_cache_accounting_clear(&c->accounting);
699 	}
700 
701 	if (attr == &sysfs_trigger_gc) {
702 		/*
703 		 * Garbage collection thread only works when sectors_to_gc < 0,
704 		 * when users write to sysfs entry trigger_gc, most of time
705 		 * they want to forcibly triger gargage collection. Here -1 is
706 		 * set to c->sectors_to_gc, to make gc_should_run() give a
707 		 * chance to permit gc thread to run. "give a chance" means
708 		 * before going into gc_should_run(), there is still chance
709 		 * that c->sectors_to_gc being set to other positive value. So
710 		 * writing sysfs entry trigger_gc won't always make sure gc
711 		 * thread takes effect.
712 		 */
713 		atomic_set(&c->sectors_to_gc, -1);
714 		wake_up_gc(c);
715 	}
716 
717 	if (attr == &sysfs_prune_cache) {
718 		struct shrink_control sc;
719 		sc.gfp_mask = GFP_KERNEL;
720 		sc.nr_to_scan = strtoul_or_return(buf);
721 		c->shrink.scan_objects(&c->shrink, &sc);
722 	}
723 
724 	sysfs_strtoul(congested_read_threshold_us,
725 		      c->congested_read_threshold_us);
726 	sysfs_strtoul(congested_write_threshold_us,
727 		      c->congested_write_threshold_us);
728 
729 	if (attr == &sysfs_errors) {
730 		v = __sysfs_match_string(error_actions, -1, buf);
731 		if (v < 0)
732 			return v;
733 
734 		c->on_error = v;
735 	}
736 
737 	if (attr == &sysfs_io_error_limit)
738 		c->error_limit = strtoul_or_return(buf);
739 
740 	/* See count_io_errors() for why 88 */
741 	if (attr == &sysfs_io_error_halflife)
742 		c->error_decay = strtoul_or_return(buf) / 88;
743 
744 	if (attr == &sysfs_io_disable) {
745 		v = strtoul_or_return(buf);
746 		if (v) {
747 			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
748 					     &c->flags))
749 				pr_warn("CACHE_SET_IO_DISABLE already set");
750 		} else {
751 			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
752 						&c->flags))
753 				pr_warn("CACHE_SET_IO_DISABLE already cleared");
754 		}
755 	}
756 
757 	sysfs_strtoul(journal_delay_ms,		c->journal_delay_ms);
758 	sysfs_strtoul(verify,			c->verify);
759 	sysfs_strtoul(key_merging_disabled,	c->key_merging_disabled);
760 	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
761 	sysfs_strtoul(gc_always_rewrite,	c->gc_always_rewrite);
762 	sysfs_strtoul(btree_shrinker_disabled,	c->shrinker_disabled);
763 	sysfs_strtoul(copy_gc_enabled,		c->copy_gc_enabled);
764 
765 	return size;
766 }
767 STORE_LOCKED(bch_cache_set)
768 
769 SHOW(bch_cache_set_internal)
770 {
771 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
772 	return bch_cache_set_show(&c->kobj, attr, buf);
773 }
774 
775 STORE(bch_cache_set_internal)
776 {
777 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
778 	return bch_cache_set_store(&c->kobj, attr, buf, size);
779 }
780 
781 static void bch_cache_set_internal_release(struct kobject *k)
782 {
783 }
784 
785 static struct attribute *bch_cache_set_files[] = {
786 	&sysfs_unregister,
787 	&sysfs_stop,
788 	&sysfs_synchronous,
789 	&sysfs_journal_delay_ms,
790 	&sysfs_flash_vol_create,
791 
792 	&sysfs_bucket_size,
793 	&sysfs_block_size,
794 	&sysfs_tree_depth,
795 	&sysfs_root_usage_percent,
796 	&sysfs_btree_cache_size,
797 	&sysfs_cache_available_percent,
798 
799 	&sysfs_average_key_size,
800 
801 	&sysfs_errors,
802 	&sysfs_io_error_limit,
803 	&sysfs_io_error_halflife,
804 	&sysfs_congested,
805 	&sysfs_congested_read_threshold_us,
806 	&sysfs_congested_write_threshold_us,
807 	&sysfs_clear_stats,
808 	NULL
809 };
810 KTYPE(bch_cache_set);
811 
812 static struct attribute *bch_cache_set_internal_files[] = {
813 	&sysfs_active_journal_entries,
814 
815 	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
816 	sysfs_time_stats_attribute_list(btree_split, sec, us)
817 	sysfs_time_stats_attribute_list(btree_sort, ms, us)
818 	sysfs_time_stats_attribute_list(btree_read, ms, us)
819 
820 	&sysfs_btree_nodes,
821 	&sysfs_btree_used_percent,
822 	&sysfs_btree_cache_max_chain,
823 
824 	&sysfs_bset_tree_stats,
825 	&sysfs_cache_read_races,
826 	&sysfs_reclaim,
827 	&sysfs_flush_write,
828 	&sysfs_retry_flush_write,
829 	&sysfs_writeback_keys_done,
830 	&sysfs_writeback_keys_failed,
831 
832 	&sysfs_trigger_gc,
833 	&sysfs_prune_cache,
834 #ifdef CONFIG_BCACHE_DEBUG
835 	&sysfs_verify,
836 	&sysfs_key_merging_disabled,
837 	&sysfs_expensive_debug_checks,
838 #endif
839 	&sysfs_gc_always_rewrite,
840 	&sysfs_btree_shrinker_disabled,
841 	&sysfs_copy_gc_enabled,
842 	&sysfs_io_disable,
843 	NULL
844 };
845 KTYPE(bch_cache_set_internal);
846 
847 static int __bch_cache_cmp(const void *l, const void *r)
848 {
849 	return *((uint16_t *)r) - *((uint16_t *)l);
850 }
851 
852 SHOW(__bch_cache)
853 {
854 	struct cache *ca = container_of(kobj, struct cache, kobj);
855 
856 	sysfs_hprint(bucket_size,	bucket_bytes(ca));
857 	sysfs_hprint(block_size,	block_bytes(ca));
858 	sysfs_print(nbuckets,		ca->sb.nbuckets);
859 	sysfs_print(discard,		ca->discard);
860 	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
861 	sysfs_hprint(btree_written,
862 		     atomic_long_read(&ca->btree_sectors_written) << 9);
863 	sysfs_hprint(metadata_written,
864 		     (atomic_long_read(&ca->meta_sectors_written) +
865 		      atomic_long_read(&ca->btree_sectors_written)) << 9);
866 
867 	sysfs_print(io_errors,
868 		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
869 
870 	if (attr == &sysfs_cache_replacement_policy)
871 		return bch_snprint_string_list(buf, PAGE_SIZE,
872 					       cache_replacement_policies,
873 					       CACHE_REPLACEMENT(&ca->sb));
874 
875 	if (attr == &sysfs_priority_stats) {
876 		struct bucket *b;
877 		size_t n = ca->sb.nbuckets, i;
878 		size_t unused = 0, available = 0, dirty = 0, meta = 0;
879 		uint64_t sum = 0;
880 		/* Compute 31 quantiles */
881 		uint16_t q[31], *p, *cached;
882 		ssize_t ret;
883 
884 		cached = p = vmalloc(array_size(sizeof(uint16_t),
885 						ca->sb.nbuckets));
886 		if (!p)
887 			return -ENOMEM;
888 
889 		mutex_lock(&ca->set->bucket_lock);
890 		for_each_bucket(b, ca) {
891 			if (!GC_SECTORS_USED(b))
892 				unused++;
893 			if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
894 				available++;
895 			if (GC_MARK(b) == GC_MARK_DIRTY)
896 				dirty++;
897 			if (GC_MARK(b) == GC_MARK_METADATA)
898 				meta++;
899 		}
900 
901 		for (i = ca->sb.first_bucket; i < n; i++)
902 			p[i] = ca->buckets[i].prio;
903 		mutex_unlock(&ca->set->bucket_lock);
904 
905 		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
906 
907 		while (n &&
908 		       !cached[n - 1])
909 			--n;
910 
911 		unused = ca->sb.nbuckets - n;
912 
913 		while (cached < p + n &&
914 		       *cached == BTREE_PRIO)
915 			cached++, n--;
916 
917 		for (i = 0; i < n; i++)
918 			sum += INITIAL_PRIO - cached[i];
919 
920 		if (n)
921 			do_div(sum, n);
922 
923 		for (i = 0; i < ARRAY_SIZE(q); i++)
924 			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
925 				(ARRAY_SIZE(q) + 1)];
926 
927 		vfree(p);
928 
929 		ret = scnprintf(buf, PAGE_SIZE,
930 				"Unused:		%zu%%\n"
931 				"Clean:		%zu%%\n"
932 				"Dirty:		%zu%%\n"
933 				"Metadata:	%zu%%\n"
934 				"Average:	%llu\n"
935 				"Sectors per Q:	%zu\n"
936 				"Quantiles:	[",
937 				unused * 100 / (size_t) ca->sb.nbuckets,
938 				available * 100 / (size_t) ca->sb.nbuckets,
939 				dirty * 100 / (size_t) ca->sb.nbuckets,
940 				meta * 100 / (size_t) ca->sb.nbuckets, sum,
941 				n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
942 
943 		for (i = 0; i < ARRAY_SIZE(q); i++)
944 			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
945 					 "%u ", q[i]);
946 		ret--;
947 
948 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
949 
950 		return ret;
951 	}
952 
953 	return 0;
954 }
955 SHOW_LOCKED(bch_cache)
956 
957 STORE(__bch_cache)
958 {
959 	struct cache *ca = container_of(kobj, struct cache, kobj);
960 	ssize_t v;
961 
962 	if (attr == &sysfs_discard) {
963 		bool v = strtoul_or_return(buf);
964 
965 		if (blk_queue_discard(bdev_get_queue(ca->bdev)))
966 			ca->discard = v;
967 
968 		if (v != CACHE_DISCARD(&ca->sb)) {
969 			SET_CACHE_DISCARD(&ca->sb, v);
970 			bcache_write_super(ca->set);
971 		}
972 	}
973 
974 	if (attr == &sysfs_cache_replacement_policy) {
975 		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
976 		if (v < 0)
977 			return v;
978 
979 		if ((unsigned) v != CACHE_REPLACEMENT(&ca->sb)) {
980 			mutex_lock(&ca->set->bucket_lock);
981 			SET_CACHE_REPLACEMENT(&ca->sb, v);
982 			mutex_unlock(&ca->set->bucket_lock);
983 
984 			bcache_write_super(ca->set);
985 		}
986 	}
987 
988 	if (attr == &sysfs_clear_stats) {
989 		atomic_long_set(&ca->sectors_written, 0);
990 		atomic_long_set(&ca->btree_sectors_written, 0);
991 		atomic_long_set(&ca->meta_sectors_written, 0);
992 		atomic_set(&ca->io_count, 0);
993 		atomic_set(&ca->io_errors, 0);
994 	}
995 
996 	return size;
997 }
998 STORE_LOCKED(bch_cache)
999 
1000 static struct attribute *bch_cache_files[] = {
1001 	&sysfs_bucket_size,
1002 	&sysfs_block_size,
1003 	&sysfs_nbuckets,
1004 	&sysfs_priority_stats,
1005 	&sysfs_discard,
1006 	&sysfs_written,
1007 	&sysfs_btree_written,
1008 	&sysfs_metadata_written,
1009 	&sysfs_io_errors,
1010 	&sysfs_clear_stats,
1011 	&sysfs_cache_replacement_policy,
1012 	NULL
1013 };
1014 KTYPE(bch_cache);
1015