xref: /openbmc/linux/drivers/md/bcache/sysfs.c (revision 930beb5a)
1 /*
2  * bcache sysfs interfaces
3  *
4  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
5  * Copyright 2012 Google, Inc.
6  */
7 
8 #include "bcache.h"
9 #include "sysfs.h"
10 #include "btree.h"
11 #include "request.h"
12 #include "writeback.h"
13 
14 #include <linux/blkdev.h>
15 #include <linux/sort.h>
16 
17 static const char * const cache_replacement_policies[] = {
18 	"lru",
19 	"fifo",
20 	"random",
21 	NULL
22 };
23 
24 static const char * const error_actions[] = {
25 	"unregister",
26 	"panic",
27 	NULL
28 };
29 
30 write_attribute(attach);
31 write_attribute(detach);
32 write_attribute(unregister);
33 write_attribute(stop);
34 write_attribute(clear_stats);
35 write_attribute(trigger_gc);
36 write_attribute(prune_cache);
37 write_attribute(flash_vol_create);
38 
39 read_attribute(bucket_size);
40 read_attribute(block_size);
41 read_attribute(nbuckets);
42 read_attribute(tree_depth);
43 read_attribute(root_usage_percent);
44 read_attribute(priority_stats);
45 read_attribute(btree_cache_size);
46 read_attribute(btree_cache_max_chain);
47 read_attribute(cache_available_percent);
48 read_attribute(written);
49 read_attribute(btree_written);
50 read_attribute(metadata_written);
51 read_attribute(active_journal_entries);
52 
53 sysfs_time_stats_attribute(btree_gc,	sec, ms);
54 sysfs_time_stats_attribute(btree_split, sec, us);
55 sysfs_time_stats_attribute(btree_sort,	ms,  us);
56 sysfs_time_stats_attribute(btree_read,	ms,  us);
57 sysfs_time_stats_attribute(try_harder,	ms,  us);
58 
59 read_attribute(btree_nodes);
60 read_attribute(btree_used_percent);
61 read_attribute(average_key_size);
62 read_attribute(dirty_data);
63 read_attribute(bset_tree_stats);
64 
65 read_attribute(state);
66 read_attribute(cache_read_races);
67 read_attribute(writeback_keys_done);
68 read_attribute(writeback_keys_failed);
69 read_attribute(io_errors);
70 read_attribute(congested);
71 rw_attribute(congested_read_threshold_us);
72 rw_attribute(congested_write_threshold_us);
73 
74 rw_attribute(sequential_cutoff);
75 rw_attribute(data_csum);
76 rw_attribute(cache_mode);
77 rw_attribute(writeback_metadata);
78 rw_attribute(writeback_running);
79 rw_attribute(writeback_percent);
80 rw_attribute(writeback_delay);
81 rw_attribute(writeback_rate);
82 
83 rw_attribute(writeback_rate_update_seconds);
84 rw_attribute(writeback_rate_d_term);
85 rw_attribute(writeback_rate_p_term_inverse);
86 read_attribute(writeback_rate_debug);
87 
88 read_attribute(stripe_size);
89 read_attribute(partial_stripes_expensive);
90 
91 rw_attribute(synchronous);
92 rw_attribute(journal_delay_ms);
93 rw_attribute(discard);
94 rw_attribute(running);
95 rw_attribute(label);
96 rw_attribute(readahead);
97 rw_attribute(errors);
98 rw_attribute(io_error_limit);
99 rw_attribute(io_error_halflife);
100 rw_attribute(verify);
101 rw_attribute(bypass_torture_test);
102 rw_attribute(key_merging_disabled);
103 rw_attribute(gc_always_rewrite);
104 rw_attribute(expensive_debug_checks);
105 rw_attribute(freelist_percent);
106 rw_attribute(cache_replacement_policy);
107 rw_attribute(btree_shrinker_disabled);
108 rw_attribute(copy_gc_enabled);
109 rw_attribute(size);
110 
111 SHOW(__bch_cached_dev)
112 {
113 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
114 					     disk.kobj);
115 	const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
116 
117 #define var(stat)		(dc->stat)
118 
119 	if (attr == &sysfs_cache_mode)
120 		return bch_snprint_string_list(buf, PAGE_SIZE,
121 					       bch_cache_modes + 1,
122 					       BDEV_CACHE_MODE(&dc->sb));
123 
124 	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
125 	var_printf(verify,		"%i");
126 	var_printf(bypass_torture_test,	"%i");
127 	var_printf(writeback_metadata,	"%i");
128 	var_printf(writeback_running,	"%i");
129 	var_print(writeback_delay);
130 	var_print(writeback_percent);
131 	sysfs_hprint(writeback_rate,	dc->writeback_rate.rate << 9);
132 
133 	var_print(writeback_rate_update_seconds);
134 	var_print(writeback_rate_d_term);
135 	var_print(writeback_rate_p_term_inverse);
136 
137 	if (attr == &sysfs_writeback_rate_debug) {
138 		char rate[20];
139 		char dirty[20];
140 		char target[20];
141 		char proportional[20];
142 		char derivative[20];
143 		char change[20];
144 		s64 next_io;
145 
146 		bch_hprint(rate,	dc->writeback_rate.rate << 9);
147 		bch_hprint(dirty,	bcache_dev_sectors_dirty(&dc->disk) << 9);
148 		bch_hprint(target,	dc->writeback_rate_target << 9);
149 		bch_hprint(proportional,dc->writeback_rate_proportional << 9);
150 		bch_hprint(derivative,	dc->writeback_rate_derivative << 9);
151 		bch_hprint(change,	dc->writeback_rate_change << 9);
152 
153 		next_io = div64_s64(dc->writeback_rate.next - local_clock(),
154 				    NSEC_PER_MSEC);
155 
156 		return sprintf(buf,
157 			       "rate:\t\t%s/sec\n"
158 			       "dirty:\t\t%s\n"
159 			       "target:\t\t%s\n"
160 			       "proportional:\t%s\n"
161 			       "derivative:\t%s\n"
162 			       "change:\t\t%s/sec\n"
163 			       "next io:\t%llims\n",
164 			       rate, dirty, target, proportional,
165 			       derivative, change, next_io);
166 	}
167 
168 	sysfs_hprint(dirty_data,
169 		     bcache_dev_sectors_dirty(&dc->disk) << 9);
170 
171 	sysfs_hprint(stripe_size,	dc->disk.stripe_size << 9);
172 	var_printf(partial_stripes_expensive,	"%u");
173 
174 	var_hprint(sequential_cutoff);
175 	var_hprint(readahead);
176 
177 	sysfs_print(running,		atomic_read(&dc->running));
178 	sysfs_print(state,		states[BDEV_STATE(&dc->sb)]);
179 
180 	if (attr == &sysfs_label) {
181 		memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
182 		buf[SB_LABEL_SIZE + 1] = '\0';
183 		strcat(buf, "\n");
184 		return strlen(buf);
185 	}
186 
187 #undef var
188 	return 0;
189 }
190 SHOW_LOCKED(bch_cached_dev)
191 
192 STORE(__cached_dev)
193 {
194 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
195 					     disk.kobj);
196 	unsigned v = size;
197 	struct cache_set *c;
198 	struct kobj_uevent_env *env;
199 
200 #define d_strtoul(var)		sysfs_strtoul(var, dc->var)
201 #define d_strtoul_nonzero(var)	sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
202 #define d_strtoi_h(var)		sysfs_hatoi(var, dc->var)
203 
204 	sysfs_strtoul(data_csum,	dc->disk.data_csum);
205 	d_strtoul(verify);
206 	d_strtoul(bypass_torture_test);
207 	d_strtoul(writeback_metadata);
208 	d_strtoul(writeback_running);
209 	d_strtoul(writeback_delay);
210 
211 	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40);
212 
213 	sysfs_strtoul_clamp(writeback_rate,
214 			    dc->writeback_rate.rate, 1, INT_MAX);
215 
216 	d_strtoul_nonzero(writeback_rate_update_seconds);
217 	d_strtoul(writeback_rate_d_term);
218 	d_strtoul_nonzero(writeback_rate_p_term_inverse);
219 
220 	d_strtoi_h(sequential_cutoff);
221 	d_strtoi_h(readahead);
222 
223 	if (attr == &sysfs_clear_stats)
224 		bch_cache_accounting_clear(&dc->accounting);
225 
226 	if (attr == &sysfs_running &&
227 	    strtoul_or_return(buf))
228 		bch_cached_dev_run(dc);
229 
230 	if (attr == &sysfs_cache_mode) {
231 		ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1);
232 
233 		if (v < 0)
234 			return v;
235 
236 		if ((unsigned) v != BDEV_CACHE_MODE(&dc->sb)) {
237 			SET_BDEV_CACHE_MODE(&dc->sb, v);
238 			bch_write_bdev_super(dc, NULL);
239 		}
240 	}
241 
242 	if (attr == &sysfs_label) {
243 		if (size > SB_LABEL_SIZE)
244 			return -EINVAL;
245 		memcpy(dc->sb.label, buf, size);
246 		if (size < SB_LABEL_SIZE)
247 			dc->sb.label[size] = '\0';
248 		if (size && dc->sb.label[size - 1] == '\n')
249 			dc->sb.label[size - 1] = '\0';
250 		bch_write_bdev_super(dc, NULL);
251 		if (dc->disk.c) {
252 			memcpy(dc->disk.c->uuids[dc->disk.id].label,
253 			       buf, SB_LABEL_SIZE);
254 			bch_uuid_write(dc->disk.c);
255 		}
256 		env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
257 		if (!env)
258 			return -ENOMEM;
259 		add_uevent_var(env, "DRIVER=bcache");
260 		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
261 		add_uevent_var(env, "CACHED_LABEL=%s", buf);
262 		kobject_uevent_env(
263 			&disk_to_dev(dc->disk.disk)->kobj, KOBJ_CHANGE, env->envp);
264 		kfree(env);
265 	}
266 
267 	if (attr == &sysfs_attach) {
268 		if (bch_parse_uuid(buf, dc->sb.set_uuid) < 16)
269 			return -EINVAL;
270 
271 		list_for_each_entry(c, &bch_cache_sets, list) {
272 			v = bch_cached_dev_attach(dc, c);
273 			if (!v)
274 				return size;
275 		}
276 
277 		pr_err("Can't attach %s: cache set not found", buf);
278 		size = v;
279 	}
280 
281 	if (attr == &sysfs_detach && dc->disk.c)
282 		bch_cached_dev_detach(dc);
283 
284 	if (attr == &sysfs_stop)
285 		bcache_device_stop(&dc->disk);
286 
287 	return size;
288 }
289 
290 STORE(bch_cached_dev)
291 {
292 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
293 					     disk.kobj);
294 
295 	mutex_lock(&bch_register_lock);
296 	size = __cached_dev_store(kobj, attr, buf, size);
297 
298 	if (attr == &sysfs_writeback_running)
299 		bch_writeback_queue(dc);
300 
301 	if (attr == &sysfs_writeback_percent)
302 		schedule_delayed_work(&dc->writeback_rate_update,
303 				      dc->writeback_rate_update_seconds * HZ);
304 
305 	mutex_unlock(&bch_register_lock);
306 	return size;
307 }
308 
309 static struct attribute *bch_cached_dev_files[] = {
310 	&sysfs_attach,
311 	&sysfs_detach,
312 	&sysfs_stop,
313 #if 0
314 	&sysfs_data_csum,
315 #endif
316 	&sysfs_cache_mode,
317 	&sysfs_writeback_metadata,
318 	&sysfs_writeback_running,
319 	&sysfs_writeback_delay,
320 	&sysfs_writeback_percent,
321 	&sysfs_writeback_rate,
322 	&sysfs_writeback_rate_update_seconds,
323 	&sysfs_writeback_rate_d_term,
324 	&sysfs_writeback_rate_p_term_inverse,
325 	&sysfs_writeback_rate_debug,
326 	&sysfs_dirty_data,
327 	&sysfs_stripe_size,
328 	&sysfs_partial_stripes_expensive,
329 	&sysfs_sequential_cutoff,
330 	&sysfs_clear_stats,
331 	&sysfs_running,
332 	&sysfs_state,
333 	&sysfs_label,
334 	&sysfs_readahead,
335 #ifdef CONFIG_BCACHE_DEBUG
336 	&sysfs_verify,
337 	&sysfs_bypass_torture_test,
338 #endif
339 	NULL
340 };
341 KTYPE(bch_cached_dev);
342 
343 SHOW(bch_flash_dev)
344 {
345 	struct bcache_device *d = container_of(kobj, struct bcache_device,
346 					       kobj);
347 	struct uuid_entry *u = &d->c->uuids[d->id];
348 
349 	sysfs_printf(data_csum,	"%i", d->data_csum);
350 	sysfs_hprint(size,	u->sectors << 9);
351 
352 	if (attr == &sysfs_label) {
353 		memcpy(buf, u->label, SB_LABEL_SIZE);
354 		buf[SB_LABEL_SIZE + 1] = '\0';
355 		strcat(buf, "\n");
356 		return strlen(buf);
357 	}
358 
359 	return 0;
360 }
361 
362 STORE(__bch_flash_dev)
363 {
364 	struct bcache_device *d = container_of(kobj, struct bcache_device,
365 					       kobj);
366 	struct uuid_entry *u = &d->c->uuids[d->id];
367 
368 	sysfs_strtoul(data_csum,	d->data_csum);
369 
370 	if (attr == &sysfs_size) {
371 		uint64_t v;
372 		strtoi_h_or_return(buf, v);
373 
374 		u->sectors = v >> 9;
375 		bch_uuid_write(d->c);
376 		set_capacity(d->disk, u->sectors);
377 	}
378 
379 	if (attr == &sysfs_label) {
380 		memcpy(u->label, buf, SB_LABEL_SIZE);
381 		bch_uuid_write(d->c);
382 	}
383 
384 	if (attr == &sysfs_unregister) {
385 		set_bit(BCACHE_DEV_DETACHING, &d->flags);
386 		bcache_device_stop(d);
387 	}
388 
389 	return size;
390 }
391 STORE_LOCKED(bch_flash_dev)
392 
393 static struct attribute *bch_flash_dev_files[] = {
394 	&sysfs_unregister,
395 #if 0
396 	&sysfs_data_csum,
397 #endif
398 	&sysfs_label,
399 	&sysfs_size,
400 	NULL
401 };
402 KTYPE(bch_flash_dev);
403 
404 SHOW(__bch_cache_set)
405 {
406 	unsigned root_usage(struct cache_set *c)
407 	{
408 		unsigned bytes = 0;
409 		struct bkey *k;
410 		struct btree *b;
411 		struct btree_iter iter;
412 
413 		goto lock_root;
414 
415 		do {
416 			rw_unlock(false, b);
417 lock_root:
418 			b = c->root;
419 			rw_lock(false, b, b->level);
420 		} while (b != c->root);
421 
422 		for_each_key_filter(b, k, &iter, bch_ptr_bad)
423 			bytes += bkey_bytes(k);
424 
425 		rw_unlock(false, b);
426 
427 		return (bytes * 100) / btree_bytes(c);
428 	}
429 
430 	size_t cache_size(struct cache_set *c)
431 	{
432 		size_t ret = 0;
433 		struct btree *b;
434 
435 		mutex_lock(&c->bucket_lock);
436 		list_for_each_entry(b, &c->btree_cache, list)
437 			ret += 1 << (b->page_order + PAGE_SHIFT);
438 
439 		mutex_unlock(&c->bucket_lock);
440 		return ret;
441 	}
442 
443 	unsigned cache_max_chain(struct cache_set *c)
444 	{
445 		unsigned ret = 0;
446 		struct hlist_head *h;
447 
448 		mutex_lock(&c->bucket_lock);
449 
450 		for (h = c->bucket_hash;
451 		     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
452 		     h++) {
453 			unsigned i = 0;
454 			struct hlist_node *p;
455 
456 			hlist_for_each(p, h)
457 				i++;
458 
459 			ret = max(ret, i);
460 		}
461 
462 		mutex_unlock(&c->bucket_lock);
463 		return ret;
464 	}
465 
466 	unsigned btree_used(struct cache_set *c)
467 	{
468 		return div64_u64(c->gc_stats.key_bytes * 100,
469 				 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
470 	}
471 
472 	unsigned average_key_size(struct cache_set *c)
473 	{
474 		return c->gc_stats.nkeys
475 			? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
476 			: 0;
477 	}
478 
479 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
480 
481 	sysfs_print(synchronous,		CACHE_SYNC(&c->sb));
482 	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
483 	sysfs_hprint(bucket_size,		bucket_bytes(c));
484 	sysfs_hprint(block_size,		block_bytes(c));
485 	sysfs_print(tree_depth,			c->root->level);
486 	sysfs_print(root_usage_percent,		root_usage(c));
487 
488 	sysfs_hprint(btree_cache_size,		cache_size(c));
489 	sysfs_print(btree_cache_max_chain,	cache_max_chain(c));
490 	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
491 
492 	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
493 	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
494 	sysfs_print_time_stats(&c->sort_time,		btree_sort, ms, us);
495 	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
496 	sysfs_print_time_stats(&c->try_harder_time,	try_harder, ms, us);
497 
498 	sysfs_print(btree_used_percent,	btree_used(c));
499 	sysfs_print(btree_nodes,	c->gc_stats.nodes);
500 	sysfs_hprint(average_key_size,	average_key_size(c));
501 
502 	sysfs_print(cache_read_races,
503 		    atomic_long_read(&c->cache_read_races));
504 
505 	sysfs_print(writeback_keys_done,
506 		    atomic_long_read(&c->writeback_keys_done));
507 	sysfs_print(writeback_keys_failed,
508 		    atomic_long_read(&c->writeback_keys_failed));
509 
510 	if (attr == &sysfs_errors)
511 		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
512 					       c->on_error);
513 
514 	/* See count_io_errors for why 88 */
515 	sysfs_print(io_error_halflife,	c->error_decay * 88);
516 	sysfs_print(io_error_limit,	c->error_limit >> IO_ERROR_SHIFT);
517 
518 	sysfs_hprint(congested,
519 		     ((uint64_t) bch_get_congested(c)) << 9);
520 	sysfs_print(congested_read_threshold_us,
521 		    c->congested_read_threshold_us);
522 	sysfs_print(congested_write_threshold_us,
523 		    c->congested_write_threshold_us);
524 
525 	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
526 	sysfs_printf(verify,			"%i", c->verify);
527 	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
528 	sysfs_printf(expensive_debug_checks,
529 		     "%i", c->expensive_debug_checks);
530 	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
531 	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
532 	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
533 
534 	if (attr == &sysfs_bset_tree_stats)
535 		return bch_bset_print_stats(c, buf);
536 
537 	return 0;
538 }
539 SHOW_LOCKED(bch_cache_set)
540 
541 STORE(__bch_cache_set)
542 {
543 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
544 
545 	if (attr == &sysfs_unregister)
546 		bch_cache_set_unregister(c);
547 
548 	if (attr == &sysfs_stop)
549 		bch_cache_set_stop(c);
550 
551 	if (attr == &sysfs_synchronous) {
552 		bool sync = strtoul_or_return(buf);
553 
554 		if (sync != CACHE_SYNC(&c->sb)) {
555 			SET_CACHE_SYNC(&c->sb, sync);
556 			bcache_write_super(c);
557 		}
558 	}
559 
560 	if (attr == &sysfs_flash_vol_create) {
561 		int r;
562 		uint64_t v;
563 		strtoi_h_or_return(buf, v);
564 
565 		r = bch_flash_dev_create(c, v);
566 		if (r)
567 			return r;
568 	}
569 
570 	if (attr == &sysfs_clear_stats) {
571 		atomic_long_set(&c->writeback_keys_done,	0);
572 		atomic_long_set(&c->writeback_keys_failed,	0);
573 
574 		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
575 		bch_cache_accounting_clear(&c->accounting);
576 	}
577 
578 	if (attr == &sysfs_trigger_gc)
579 		wake_up_gc(c);
580 
581 	if (attr == &sysfs_prune_cache) {
582 		struct shrink_control sc;
583 		sc.gfp_mask = GFP_KERNEL;
584 		sc.nr_to_scan = strtoul_or_return(buf);
585 		c->shrink.scan_objects(&c->shrink, &sc);
586 	}
587 
588 	sysfs_strtoul(congested_read_threshold_us,
589 		      c->congested_read_threshold_us);
590 	sysfs_strtoul(congested_write_threshold_us,
591 		      c->congested_write_threshold_us);
592 
593 	if (attr == &sysfs_errors) {
594 		ssize_t v = bch_read_string_list(buf, error_actions);
595 
596 		if (v < 0)
597 			return v;
598 
599 		c->on_error = v;
600 	}
601 
602 	if (attr == &sysfs_io_error_limit)
603 		c->error_limit = strtoul_or_return(buf) << IO_ERROR_SHIFT;
604 
605 	/* See count_io_errors() for why 88 */
606 	if (attr == &sysfs_io_error_halflife)
607 		c->error_decay = strtoul_or_return(buf) / 88;
608 
609 	sysfs_strtoul(journal_delay_ms,		c->journal_delay_ms);
610 	sysfs_strtoul(verify,			c->verify);
611 	sysfs_strtoul(key_merging_disabled,	c->key_merging_disabled);
612 	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
613 	sysfs_strtoul(gc_always_rewrite,	c->gc_always_rewrite);
614 	sysfs_strtoul(btree_shrinker_disabled,	c->shrinker_disabled);
615 	sysfs_strtoul(copy_gc_enabled,		c->copy_gc_enabled);
616 
617 	return size;
618 }
619 STORE_LOCKED(bch_cache_set)
620 
621 SHOW(bch_cache_set_internal)
622 {
623 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
624 	return bch_cache_set_show(&c->kobj, attr, buf);
625 }
626 
627 STORE(bch_cache_set_internal)
628 {
629 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
630 	return bch_cache_set_store(&c->kobj, attr, buf, size);
631 }
632 
633 static void bch_cache_set_internal_release(struct kobject *k)
634 {
635 }
636 
637 static struct attribute *bch_cache_set_files[] = {
638 	&sysfs_unregister,
639 	&sysfs_stop,
640 	&sysfs_synchronous,
641 	&sysfs_journal_delay_ms,
642 	&sysfs_flash_vol_create,
643 
644 	&sysfs_bucket_size,
645 	&sysfs_block_size,
646 	&sysfs_tree_depth,
647 	&sysfs_root_usage_percent,
648 	&sysfs_btree_cache_size,
649 	&sysfs_cache_available_percent,
650 
651 	&sysfs_average_key_size,
652 
653 	&sysfs_errors,
654 	&sysfs_io_error_limit,
655 	&sysfs_io_error_halflife,
656 	&sysfs_congested,
657 	&sysfs_congested_read_threshold_us,
658 	&sysfs_congested_write_threshold_us,
659 	&sysfs_clear_stats,
660 	NULL
661 };
662 KTYPE(bch_cache_set);
663 
664 static struct attribute *bch_cache_set_internal_files[] = {
665 	&sysfs_active_journal_entries,
666 
667 	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
668 	sysfs_time_stats_attribute_list(btree_split, sec, us)
669 	sysfs_time_stats_attribute_list(btree_sort, ms, us)
670 	sysfs_time_stats_attribute_list(btree_read, ms, us)
671 	sysfs_time_stats_attribute_list(try_harder, ms, us)
672 
673 	&sysfs_btree_nodes,
674 	&sysfs_btree_used_percent,
675 	&sysfs_btree_cache_max_chain,
676 
677 	&sysfs_bset_tree_stats,
678 	&sysfs_cache_read_races,
679 	&sysfs_writeback_keys_done,
680 	&sysfs_writeback_keys_failed,
681 
682 	&sysfs_trigger_gc,
683 	&sysfs_prune_cache,
684 #ifdef CONFIG_BCACHE_DEBUG
685 	&sysfs_verify,
686 	&sysfs_key_merging_disabled,
687 	&sysfs_expensive_debug_checks,
688 #endif
689 	&sysfs_gc_always_rewrite,
690 	&sysfs_btree_shrinker_disabled,
691 	&sysfs_copy_gc_enabled,
692 	NULL
693 };
694 KTYPE(bch_cache_set_internal);
695 
696 SHOW(__bch_cache)
697 {
698 	struct cache *ca = container_of(kobj, struct cache, kobj);
699 
700 	sysfs_hprint(bucket_size,	bucket_bytes(ca));
701 	sysfs_hprint(block_size,	block_bytes(ca));
702 	sysfs_print(nbuckets,		ca->sb.nbuckets);
703 	sysfs_print(discard,		ca->discard);
704 	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
705 	sysfs_hprint(btree_written,
706 		     atomic_long_read(&ca->btree_sectors_written) << 9);
707 	sysfs_hprint(metadata_written,
708 		     (atomic_long_read(&ca->meta_sectors_written) +
709 		      atomic_long_read(&ca->btree_sectors_written)) << 9);
710 
711 	sysfs_print(io_errors,
712 		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
713 
714 	sysfs_print(freelist_percent, ca->free.size * 100 /
715 		    ((size_t) ca->sb.nbuckets));
716 
717 	if (attr == &sysfs_cache_replacement_policy)
718 		return bch_snprint_string_list(buf, PAGE_SIZE,
719 					       cache_replacement_policies,
720 					       CACHE_REPLACEMENT(&ca->sb));
721 
722 	if (attr == &sysfs_priority_stats) {
723 		int cmp(const void *l, const void *r)
724 		{	return *((uint16_t *) r) - *((uint16_t *) l); }
725 
726 		size_t n = ca->sb.nbuckets, i, unused, btree;
727 		uint64_t sum = 0;
728 		/* Compute 31 quantiles */
729 		uint16_t q[31], *p, *cached;
730 		ssize_t ret;
731 
732 		cached = p = vmalloc(ca->sb.nbuckets * sizeof(uint16_t));
733 		if (!p)
734 			return -ENOMEM;
735 
736 		mutex_lock(&ca->set->bucket_lock);
737 		for (i = ca->sb.first_bucket; i < n; i++)
738 			p[i] = ca->buckets[i].prio;
739 		mutex_unlock(&ca->set->bucket_lock);
740 
741 		sort(p, n, sizeof(uint16_t), cmp, NULL);
742 
743 		while (n &&
744 		       !cached[n - 1])
745 			--n;
746 
747 		unused = ca->sb.nbuckets - n;
748 
749 		while (cached < p + n &&
750 		       *cached == BTREE_PRIO)
751 			cached++;
752 
753 		btree = cached - p;
754 		n -= btree;
755 
756 		for (i = 0; i < n; i++)
757 			sum += INITIAL_PRIO - cached[i];
758 
759 		if (n)
760 			do_div(sum, n);
761 
762 		for (i = 0; i < ARRAY_SIZE(q); i++)
763 			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
764 				(ARRAY_SIZE(q) + 1)];
765 
766 		vfree(p);
767 
768 		ret = scnprintf(buf, PAGE_SIZE,
769 				"Unused:		%zu%%\n"
770 				"Metadata:	%zu%%\n"
771 				"Average:	%llu\n"
772 				"Sectors per Q:	%zu\n"
773 				"Quantiles:	[",
774 				unused * 100 / (size_t) ca->sb.nbuckets,
775 				btree * 100 / (size_t) ca->sb.nbuckets, sum,
776 				n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
777 
778 		for (i = 0; i < ARRAY_SIZE(q); i++)
779 			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
780 					 "%u ", q[i]);
781 		ret--;
782 
783 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
784 
785 		return ret;
786 	}
787 
788 	return 0;
789 }
790 SHOW_LOCKED(bch_cache)
791 
792 STORE(__bch_cache)
793 {
794 	struct cache *ca = container_of(kobj, struct cache, kobj);
795 
796 	if (attr == &sysfs_discard) {
797 		bool v = strtoul_or_return(buf);
798 
799 		if (blk_queue_discard(bdev_get_queue(ca->bdev)))
800 			ca->discard = v;
801 
802 		if (v != CACHE_DISCARD(&ca->sb)) {
803 			SET_CACHE_DISCARD(&ca->sb, v);
804 			bcache_write_super(ca->set);
805 		}
806 	}
807 
808 	if (attr == &sysfs_cache_replacement_policy) {
809 		ssize_t v = bch_read_string_list(buf, cache_replacement_policies);
810 
811 		if (v < 0)
812 			return v;
813 
814 		if ((unsigned) v != CACHE_REPLACEMENT(&ca->sb)) {
815 			mutex_lock(&ca->set->bucket_lock);
816 			SET_CACHE_REPLACEMENT(&ca->sb, v);
817 			mutex_unlock(&ca->set->bucket_lock);
818 
819 			bcache_write_super(ca->set);
820 		}
821 	}
822 
823 	if (attr == &sysfs_freelist_percent) {
824 		DECLARE_FIFO(long, free);
825 		long i;
826 		size_t p = strtoul_or_return(buf);
827 
828 		p = clamp_t(size_t,
829 			    ((size_t) ca->sb.nbuckets * p) / 100,
830 			    roundup_pow_of_two(ca->sb.nbuckets) >> 9,
831 			    ca->sb.nbuckets / 2);
832 
833 		if (!init_fifo_exact(&free, p, GFP_KERNEL))
834 			return -ENOMEM;
835 
836 		mutex_lock(&ca->set->bucket_lock);
837 
838 		fifo_move(&free, &ca->free);
839 		fifo_swap(&free, &ca->free);
840 
841 		mutex_unlock(&ca->set->bucket_lock);
842 
843 		while (fifo_pop(&free, i))
844 			atomic_dec(&ca->buckets[i].pin);
845 
846 		free_fifo(&free);
847 	}
848 
849 	if (attr == &sysfs_clear_stats) {
850 		atomic_long_set(&ca->sectors_written, 0);
851 		atomic_long_set(&ca->btree_sectors_written, 0);
852 		atomic_long_set(&ca->meta_sectors_written, 0);
853 		atomic_set(&ca->io_count, 0);
854 		atomic_set(&ca->io_errors, 0);
855 	}
856 
857 	return size;
858 }
859 STORE_LOCKED(bch_cache)
860 
861 static struct attribute *bch_cache_files[] = {
862 	&sysfs_bucket_size,
863 	&sysfs_block_size,
864 	&sysfs_nbuckets,
865 	&sysfs_priority_stats,
866 	&sysfs_discard,
867 	&sysfs_written,
868 	&sysfs_btree_written,
869 	&sysfs_metadata_written,
870 	&sysfs_io_errors,
871 	&sysfs_clear_stats,
872 	&sysfs_freelist_percent,
873 	&sysfs_cache_replacement_policy,
874 	NULL
875 };
876 KTYPE(bch_cache);
877