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#include "features.h"
15
16#include <linux/blkdev.h>
17#include <linux/sort.h>
18#include <linux/sched/clock.h>
19
20extern bool bcache_is_reboot;
21
22/* Default is 0 ("writethrough") */
23static const char * const bch_cache_modes[] = {
24	"writethrough",
25	"writeback",
26	"writearound",
27	"none",
28	NULL
29};
30
31static const char * const bch_reada_cache_policies[] = {
32	"all",
33	"meta-only",
34	NULL
35};
36
37/* Default is 0 ("auto") */
38static const char * const bch_stop_on_failure_modes[] = {
39	"auto",
40	"always",
41	NULL
42};
43
44static const char * const cache_replacement_policies[] = {
45	"lru",
46	"fifo",
47	"random",
48	NULL
49};
50
51static const char * const error_actions[] = {
52	"unregister",
53	"panic",
54	NULL
55};
56
57write_attribute(attach);
58write_attribute(detach);
59write_attribute(unregister);
60write_attribute(stop);
61write_attribute(clear_stats);
62write_attribute(trigger_gc);
63write_attribute(prune_cache);
64write_attribute(flash_vol_create);
65
66read_attribute(bucket_size);
67read_attribute(block_size);
68read_attribute(nbuckets);
69read_attribute(tree_depth);
70read_attribute(root_usage_percent);
71read_attribute(priority_stats);
72read_attribute(btree_cache_size);
73read_attribute(btree_cache_max_chain);
74read_attribute(cache_available_percent);
75read_attribute(written);
76read_attribute(btree_written);
77read_attribute(metadata_written);
78read_attribute(active_journal_entries);
79read_attribute(backing_dev_name);
80read_attribute(backing_dev_uuid);
81
82sysfs_time_stats_attribute(btree_gc,	sec, ms);
83sysfs_time_stats_attribute(btree_split, sec, us);
84sysfs_time_stats_attribute(btree_sort,	ms,  us);
85sysfs_time_stats_attribute(btree_read,	ms,  us);
86
87read_attribute(btree_nodes);
88read_attribute(btree_used_percent);
89read_attribute(average_key_size);
90read_attribute(dirty_data);
91read_attribute(bset_tree_stats);
92read_attribute(feature_compat);
93read_attribute(feature_ro_compat);
94read_attribute(feature_incompat);
95
96read_attribute(state);
97read_attribute(cache_read_races);
98read_attribute(reclaim);
99read_attribute(reclaimed_journal_buckets);
100read_attribute(flush_write);
101read_attribute(writeback_keys_done);
102read_attribute(writeback_keys_failed);
103read_attribute(io_errors);
104read_attribute(congested);
105read_attribute(cutoff_writeback);
106read_attribute(cutoff_writeback_sync);
107rw_attribute(congested_read_threshold_us);
108rw_attribute(congested_write_threshold_us);
109
110rw_attribute(sequential_cutoff);
111rw_attribute(data_csum);
112rw_attribute(cache_mode);
113rw_attribute(readahead_cache_policy);
114rw_attribute(stop_when_cache_set_failed);
115rw_attribute(writeback_metadata);
116rw_attribute(writeback_running);
117rw_attribute(writeback_percent);
118rw_attribute(writeback_delay);
119rw_attribute(writeback_rate);
120
121rw_attribute(writeback_rate_update_seconds);
122rw_attribute(writeback_rate_i_term_inverse);
123rw_attribute(writeback_rate_p_term_inverse);
124rw_attribute(writeback_rate_minimum);
125read_attribute(writeback_rate_debug);
126
127read_attribute(stripe_size);
128read_attribute(partial_stripes_expensive);
129
130rw_attribute(synchronous);
131rw_attribute(journal_delay_ms);
132rw_attribute(io_disable);
133rw_attribute(discard);
134rw_attribute(running);
135rw_attribute(label);
136rw_attribute(readahead);
137rw_attribute(errors);
138rw_attribute(io_error_limit);
139rw_attribute(io_error_halflife);
140rw_attribute(verify);
141rw_attribute(bypass_torture_test);
142rw_attribute(key_merging_disabled);
143rw_attribute(gc_always_rewrite);
144rw_attribute(expensive_debug_checks);
145rw_attribute(cache_replacement_policy);
146rw_attribute(btree_shrinker_disabled);
147rw_attribute(copy_gc_enabled);
148rw_attribute(idle_max_writeback_rate);
149rw_attribute(gc_after_writeback);
150rw_attribute(size);
151
152static ssize_t bch_snprint_string_list(char *buf,
153				       size_t size,
154				       const char * const list[],
155				       size_t selected)
156{
157	char *out = buf;
158	size_t i;
159
160	for (i = 0; list[i]; i++)
161		out += scnprintf(out, buf + size - out,
162				i == selected ? "[%s] " : "%s ", list[i]);
163
164	out[-1] = '\n';
165	return out - buf;
166}
167
168SHOW(__bch_cached_dev)
169{
170	struct cached_dev *dc = container_of(kobj, struct cached_dev,
171					     disk.kobj);
172	char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
173	int wb = dc->writeback_running;
174
175#define var(stat)		(dc->stat)
176
177	if (attr == &sysfs_cache_mode)
178		return bch_snprint_string_list(buf, PAGE_SIZE,
179					       bch_cache_modes,
180					       BDEV_CACHE_MODE(&dc->sb));
181
182	if (attr == &sysfs_readahead_cache_policy)
183		return bch_snprint_string_list(buf, PAGE_SIZE,
184					      bch_reada_cache_policies,
185					      dc->cache_readahead_policy);
186
187	if (attr == &sysfs_stop_when_cache_set_failed)
188		return bch_snprint_string_list(buf, PAGE_SIZE,
189					       bch_stop_on_failure_modes,
190					       dc->stop_when_cache_set_failed);
191
192
193	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
194	var_printf(verify,		"%i");
195	var_printf(bypass_torture_test,	"%i");
196	var_printf(writeback_metadata,	"%i");
197	var_printf(writeback_running,	"%i");
198	var_print(writeback_delay);
199	var_print(writeback_percent);
200	sysfs_hprint(writeback_rate,
201		     wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
202	sysfs_printf(io_errors,		"%i", atomic_read(&dc->io_errors));
203	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
204	sysfs_printf(io_disable,	"%i", dc->io_disable);
205	var_print(writeback_rate_update_seconds);
206	var_print(writeback_rate_i_term_inverse);
207	var_print(writeback_rate_p_term_inverse);
208	var_print(writeback_rate_minimum);
209
210	if (attr == &sysfs_writeback_rate_debug) {
211		char rate[20];
212		char dirty[20];
213		char target[20];
214		char proportional[20];
215		char integral[20];
216		char change[20];
217		s64 next_io;
218
219		/*
220		 * Except for dirty and target, other values should
221		 * be 0 if writeback is not running.
222		 */
223		bch_hprint(rate,
224			   wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
225			      : 0);
226		bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
227		bch_hprint(target, dc->writeback_rate_target << 9);
228		bch_hprint(proportional,
229			   wb ? dc->writeback_rate_proportional << 9 : 0);
230		bch_hprint(integral,
231			   wb ? dc->writeback_rate_integral_scaled << 9 : 0);
232		bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
233		next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
234					 NSEC_PER_MSEC) : 0;
235
236		return sprintf(buf,
237			       "rate:\t\t%s/sec\n"
238			       "dirty:\t\t%s\n"
239			       "target:\t\t%s\n"
240			       "proportional:\t%s\n"
241			       "integral:\t%s\n"
242			       "change:\t\t%s/sec\n"
243			       "next io:\t%llims\n",
244			       rate, dirty, target, proportional,
245			       integral, change, next_io);
246	}
247
248	sysfs_hprint(dirty_data,
249		     bcache_dev_sectors_dirty(&dc->disk) << 9);
250
251	sysfs_hprint(stripe_size,	 ((uint64_t)dc->disk.stripe_size) << 9);
252	var_printf(partial_stripes_expensive,	"%u");
253
254	var_hprint(sequential_cutoff);
255	var_hprint(readahead);
256
257	sysfs_print(running,		atomic_read(&dc->running));
258	sysfs_print(state,		states[BDEV_STATE(&dc->sb)]);
259
260	if (attr == &sysfs_label) {
261		memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
262		buf[SB_LABEL_SIZE + 1] = '\0';
263		strcat(buf, "\n");
264		return strlen(buf);
265	}
266
267	if (attr == &sysfs_backing_dev_name) {
268		snprintf(buf, BDEVNAME_SIZE + 1, "%s", dc->backing_dev_name);
269		strcat(buf, "\n");
270		return strlen(buf);
271	}
272
273	if (attr == &sysfs_backing_dev_uuid) {
274		/* convert binary uuid into 36-byte string plus '\0' */
275		snprintf(buf, 36+1, "%pU", dc->sb.uuid);
276		strcat(buf, "\n");
277		return strlen(buf);
278	}
279
280#undef var
281	return 0;
282}
283SHOW_LOCKED(bch_cached_dev)
284
285STORE(__cached_dev)
286{
287	struct cached_dev *dc = container_of(kobj, struct cached_dev,
288					     disk.kobj);
289	ssize_t v;
290	struct cache_set *c;
291	struct kobj_uevent_env *env;
292
293	/* no user space access if system is rebooting */
294	if (bcache_is_reboot)
295		return -EBUSY;
296
297#define d_strtoul(var)		sysfs_strtoul(var, dc->var)
298#define d_strtoul_nonzero(var)	sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
299#define d_strtoi_h(var)		sysfs_hatoi(var, dc->var)
300
301	sysfs_strtoul(data_csum,	dc->disk.data_csum);
302	d_strtoul(verify);
303	sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test);
304	sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata);
305	sysfs_strtoul_bool(writeback_running, dc->writeback_running);
306	sysfs_strtoul_clamp(writeback_delay, dc->writeback_delay, 0, UINT_MAX);
307
308	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent,
309			    0, bch_cutoff_writeback);
310
311	if (attr == &sysfs_writeback_rate) {
312		ssize_t ret;
313		long int v = atomic_long_read(&dc->writeback_rate.rate);
314
315		ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
316
317		if (!ret) {
318			atomic_long_set(&dc->writeback_rate.rate, v);
319			ret = size;
320		}
321
322		return ret;
323	}
324
325	sysfs_strtoul_clamp(writeback_rate_update_seconds,
326			    dc->writeback_rate_update_seconds,
327			    1, WRITEBACK_RATE_UPDATE_SECS_MAX);
328	sysfs_strtoul_clamp(writeback_rate_i_term_inverse,
329			    dc->writeback_rate_i_term_inverse,
330			    1, UINT_MAX);
331	sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
332			    dc->writeback_rate_p_term_inverse,
333			    1, UINT_MAX);
334	sysfs_strtoul_clamp(writeback_rate_minimum,
335			    dc->writeback_rate_minimum,
336			    1, UINT_MAX);
337
338	sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);
339
340	if (attr == &sysfs_io_disable) {
341		int v = strtoul_or_return(buf);
342
343		dc->io_disable = v ? 1 : 0;
344	}
345
346	sysfs_strtoul_clamp(sequential_cutoff,
347			    dc->sequential_cutoff,
348			    0, UINT_MAX);
349	d_strtoi_h(readahead);
350
351	if (attr == &sysfs_clear_stats)
352		bch_cache_accounting_clear(&dc->accounting);
353
354	if (attr == &sysfs_running &&
355	    strtoul_or_return(buf)) {
356		v = bch_cached_dev_run(dc);
357		if (v)
358			return v;
359	}
360
361	if (attr == &sysfs_cache_mode) {
362		v = __sysfs_match_string(bch_cache_modes, -1, buf);
363		if (v < 0)
364			return v;
365
366		if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
367			SET_BDEV_CACHE_MODE(&dc->sb, v);
368			bch_write_bdev_super(dc, NULL);
369		}
370	}
371
372	if (attr == &sysfs_readahead_cache_policy) {
373		v = __sysfs_match_string(bch_reada_cache_policies, -1, buf);
374		if (v < 0)
375			return v;
376
377		if ((unsigned int) v != dc->cache_readahead_policy)
378			dc->cache_readahead_policy = v;
379	}
380
381	if (attr == &sysfs_stop_when_cache_set_failed) {
382		v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
383		if (v < 0)
384			return v;
385
386		dc->stop_when_cache_set_failed = v;
387	}
388
389	if (attr == &sysfs_label) {
390		if (size > SB_LABEL_SIZE)
391			return -EINVAL;
392		memcpy(dc->sb.label, buf, size);
393		if (size < SB_LABEL_SIZE)
394			dc->sb.label[size] = '\0';
395		if (size && dc->sb.label[size - 1] == '\n')
396			dc->sb.label[size - 1] = '\0';
397		bch_write_bdev_super(dc, NULL);
398		if (dc->disk.c) {
399			memcpy(dc->disk.c->uuids[dc->disk.id].label,
400			       buf, SB_LABEL_SIZE);
401			bch_uuid_write(dc->disk.c);
402		}
403		env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
404		if (!env)
405			return -ENOMEM;
406		add_uevent_var(env, "DRIVER=bcache");
407		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
408		add_uevent_var(env, "CACHED_LABEL=%s", buf);
409		kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj,
410				   KOBJ_CHANGE,
411				   env->envp);
412		kfree(env);
413	}
414
415	if (attr == &sysfs_attach) {
416		uint8_t		set_uuid[16];
417
418		if (bch_parse_uuid(buf, set_uuid) < 16)
419			return -EINVAL;
420
421		v = -ENOENT;
422		list_for_each_entry(c, &bch_cache_sets, list) {
423			v = bch_cached_dev_attach(dc, c, set_uuid);
424			if (!v)
425				return size;
426		}
427		if (v == -ENOENT)
428			pr_err("Can't attach %s: cache set not found\n", buf);
429		return v;
430	}
431
432	if (attr == &sysfs_detach && dc->disk.c)
433		bch_cached_dev_detach(dc);
434
435	if (attr == &sysfs_stop)
436		bcache_device_stop(&dc->disk);
437
438	return size;
439}
440
441STORE(bch_cached_dev)
442{
443	struct cached_dev *dc = container_of(kobj, struct cached_dev,
444					     disk.kobj);
445
446	/* no user space access if system is rebooting */
447	if (bcache_is_reboot)
448		return -EBUSY;
449
450	mutex_lock(&bch_register_lock);
451	size = __cached_dev_store(kobj, attr, buf, size);
452
453	if (attr == &sysfs_writeback_running) {
454		/* dc->writeback_running changed in __cached_dev_store() */
455		if (IS_ERR_OR_NULL(dc->writeback_thread)) {
456			/*
457			 * reject setting it to 1 via sysfs if writeback
458			 * kthread is not created yet.
459			 */
460			if (dc->writeback_running) {
461				dc->writeback_running = false;
462				pr_err("%s: failed to run non-existent writeback thread\n",
463						dc->disk.disk->disk_name);
464			}
465		} else
466			/*
467			 * writeback kthread will check if dc->writeback_running
468			 * is true or false.
469			 */
470			bch_writeback_queue(dc);
471	}
472
473	/*
474	 * Only set BCACHE_DEV_WB_RUNNING when cached device attached to
475	 * a cache set, otherwise it doesn't make sense.
476	 */
477	if (attr == &sysfs_writeback_percent)
478		if ((dc->disk.c != NULL) &&
479		    (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)))
480			schedule_delayed_work(&dc->writeback_rate_update,
481				      dc->writeback_rate_update_seconds * HZ);
482
483	mutex_unlock(&bch_register_lock);
484	return size;
485}
486
487static struct attribute *bch_cached_dev_files[] = {
488	&sysfs_attach,
489	&sysfs_detach,
490	&sysfs_stop,
491#if 0
492	&sysfs_data_csum,
493#endif
494	&sysfs_cache_mode,
495	&sysfs_readahead_cache_policy,
496	&sysfs_stop_when_cache_set_failed,
497	&sysfs_writeback_metadata,
498	&sysfs_writeback_running,
499	&sysfs_writeback_delay,
500	&sysfs_writeback_percent,
501	&sysfs_writeback_rate,
502	&sysfs_writeback_rate_update_seconds,
503	&sysfs_writeback_rate_i_term_inverse,
504	&sysfs_writeback_rate_p_term_inverse,
505	&sysfs_writeback_rate_minimum,
506	&sysfs_writeback_rate_debug,
507	&sysfs_io_errors,
508	&sysfs_io_error_limit,
509	&sysfs_io_disable,
510	&sysfs_dirty_data,
511	&sysfs_stripe_size,
512	&sysfs_partial_stripes_expensive,
513	&sysfs_sequential_cutoff,
514	&sysfs_clear_stats,
515	&sysfs_running,
516	&sysfs_state,
517	&sysfs_label,
518	&sysfs_readahead,
519#ifdef CONFIG_BCACHE_DEBUG
520	&sysfs_verify,
521	&sysfs_bypass_torture_test,
522#endif
523	&sysfs_backing_dev_name,
524	&sysfs_backing_dev_uuid,
525	NULL
526};
527KTYPE(bch_cached_dev);
528
529SHOW(bch_flash_dev)
530{
531	struct bcache_device *d = container_of(kobj, struct bcache_device,
532					       kobj);
533	struct uuid_entry *u = &d->c->uuids[d->id];
534
535	sysfs_printf(data_csum,	"%i", d->data_csum);
536	sysfs_hprint(size,	u->sectors << 9);
537
538	if (attr == &sysfs_label) {
539		memcpy(buf, u->label, SB_LABEL_SIZE);
540		buf[SB_LABEL_SIZE + 1] = '\0';
541		strcat(buf, "\n");
542		return strlen(buf);
543	}
544
545	return 0;
546}
547
548STORE(__bch_flash_dev)
549{
550	struct bcache_device *d = container_of(kobj, struct bcache_device,
551					       kobj);
552	struct uuid_entry *u = &d->c->uuids[d->id];
553
554	/* no user space access if system is rebooting */
555	if (bcache_is_reboot)
556		return -EBUSY;
557
558	sysfs_strtoul(data_csum,	d->data_csum);
559
560	if (attr == &sysfs_size) {
561		uint64_t v;
562
563		strtoi_h_or_return(buf, v);
564
565		u->sectors = v >> 9;
566		bch_uuid_write(d->c);
567		set_capacity(d->disk, u->sectors);
568	}
569
570	if (attr == &sysfs_label) {
571		memcpy(u->label, buf, SB_LABEL_SIZE);
572		bch_uuid_write(d->c);
573	}
574
575	if (attr == &sysfs_unregister) {
576		set_bit(BCACHE_DEV_DETACHING, &d->flags);
577		bcache_device_stop(d);
578	}
579
580	return size;
581}
582STORE_LOCKED(bch_flash_dev)
583
584static struct attribute *bch_flash_dev_files[] = {
585	&sysfs_unregister,
586#if 0
587	&sysfs_data_csum,
588#endif
589	&sysfs_label,
590	&sysfs_size,
591	NULL
592};
593KTYPE(bch_flash_dev);
594
595struct bset_stats_op {
596	struct btree_op op;
597	size_t nodes;
598	struct bset_stats stats;
599};
600
601static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b)
602{
603	struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op);
604
605	op->nodes++;
606	bch_btree_keys_stats(&b->keys, &op->stats);
607
608	return MAP_CONTINUE;
609}
610
611static int bch_bset_print_stats(struct cache_set *c, char *buf)
612{
613	struct bset_stats_op op;
614	int ret;
615
616	memset(&op, 0, sizeof(op));
617	bch_btree_op_init(&op.op, -1);
618
619	ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats);
620	if (ret < 0)
621		return ret;
622
623	return snprintf(buf, PAGE_SIZE,
624			"btree nodes:		%zu\n"
625			"written sets:		%zu\n"
626			"unwritten sets:		%zu\n"
627			"written key bytes:	%zu\n"
628			"unwritten key bytes:	%zu\n"
629			"floats:			%zu\n"
630			"failed:			%zu\n",
631			op.nodes,
632			op.stats.sets_written, op.stats.sets_unwritten,
633			op.stats.bytes_written, op.stats.bytes_unwritten,
634			op.stats.floats, op.stats.failed);
635}
636
637static unsigned int bch_root_usage(struct cache_set *c)
638{
639	unsigned int bytes = 0;
640	struct bkey *k;
641	struct btree *b;
642	struct btree_iter iter;
643
644	goto lock_root;
645
646	do {
647		rw_unlock(false, b);
648lock_root:
649		b = c->root;
650		rw_lock(false, b, b->level);
651	} while (b != c->root);
652
653	for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
654		bytes += bkey_bytes(k);
655
656	rw_unlock(false, b);
657
658	return (bytes * 100) / btree_bytes(c);
659}
660
661static size_t bch_cache_size(struct cache_set *c)
662{
663	size_t ret = 0;
664	struct btree *b;
665
666	mutex_lock(&c->bucket_lock);
667	list_for_each_entry(b, &c->btree_cache, list)
668		ret += 1 << (b->keys.page_order + PAGE_SHIFT);
669
670	mutex_unlock(&c->bucket_lock);
671	return ret;
672}
673
674static unsigned int bch_cache_max_chain(struct cache_set *c)
675{
676	unsigned int ret = 0;
677	struct hlist_head *h;
678
679	mutex_lock(&c->bucket_lock);
680
681	for (h = c->bucket_hash;
682	     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
683	     h++) {
684		unsigned int i = 0;
685		struct hlist_node *p;
686
687		hlist_for_each(p, h)
688			i++;
689
690		ret = max(ret, i);
691	}
692
693	mutex_unlock(&c->bucket_lock);
694	return ret;
695}
696
697static unsigned int bch_btree_used(struct cache_set *c)
698{
699	return div64_u64(c->gc_stats.key_bytes * 100,
700			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
701}
702
703static unsigned int bch_average_key_size(struct cache_set *c)
704{
705	return c->gc_stats.nkeys
706		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
707		: 0;
708}
709
710SHOW(__bch_cache_set)
711{
712	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
713
714	sysfs_print(synchronous,		CACHE_SYNC(&c->cache->sb));
715	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
716	sysfs_hprint(bucket_size,		bucket_bytes(c->cache));
717	sysfs_hprint(block_size,		block_bytes(c->cache));
718	sysfs_print(tree_depth,			c->root->level);
719	sysfs_print(root_usage_percent,		bch_root_usage(c));
720
721	sysfs_hprint(btree_cache_size,		bch_cache_size(c));
722	sysfs_print(btree_cache_max_chain,	bch_cache_max_chain(c));
723	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
724
725	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
726	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
727	sysfs_print_time_stats(&c->sort.time,		btree_sort, ms, us);
728	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
729
730	sysfs_print(btree_used_percent,	bch_btree_used(c));
731	sysfs_print(btree_nodes,	c->gc_stats.nodes);
732	sysfs_hprint(average_key_size,	bch_average_key_size(c));
733
734	sysfs_print(cache_read_races,
735		    atomic_long_read(&c->cache_read_races));
736
737	sysfs_print(reclaim,
738		    atomic_long_read(&c->reclaim));
739
740	sysfs_print(reclaimed_journal_buckets,
741		    atomic_long_read(&c->reclaimed_journal_buckets));
742
743	sysfs_print(flush_write,
744		    atomic_long_read(&c->flush_write));
745
746	sysfs_print(writeback_keys_done,
747		    atomic_long_read(&c->writeback_keys_done));
748	sysfs_print(writeback_keys_failed,
749		    atomic_long_read(&c->writeback_keys_failed));
750
751	if (attr == &sysfs_errors)
752		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
753					       c->on_error);
754
755	/* See count_io_errors for why 88 */
756	sysfs_print(io_error_halflife,	c->error_decay * 88);
757	sysfs_print(io_error_limit,	c->error_limit);
758
759	sysfs_hprint(congested,
760		     ((uint64_t) bch_get_congested(c)) << 9);
761	sysfs_print(congested_read_threshold_us,
762		    c->congested_read_threshold_us);
763	sysfs_print(congested_write_threshold_us,
764		    c->congested_write_threshold_us);
765
766	sysfs_print(cutoff_writeback, bch_cutoff_writeback);
767	sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync);
768
769	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
770	sysfs_printf(verify,			"%i", c->verify);
771	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
772	sysfs_printf(expensive_debug_checks,
773		     "%i", c->expensive_debug_checks);
774	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
775	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
776	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
777	sysfs_printf(idle_max_writeback_rate,	"%i",
778		     c->idle_max_writeback_rate_enabled);
779	sysfs_printf(gc_after_writeback,	"%i", c->gc_after_writeback);
780	sysfs_printf(io_disable,		"%i",
781		     test_bit(CACHE_SET_IO_DISABLE, &c->flags));
782
783	if (attr == &sysfs_bset_tree_stats)
784		return bch_bset_print_stats(c, buf);
785
786	if (attr == &sysfs_feature_compat)
787		return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE);
788	if (attr == &sysfs_feature_ro_compat)
789		return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE);
790	if (attr == &sysfs_feature_incompat)
791		return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE);
792
793	return 0;
794}
795SHOW_LOCKED(bch_cache_set)
796
797STORE(__bch_cache_set)
798{
799	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
800	ssize_t v;
801
802	/* no user space access if system is rebooting */
803	if (bcache_is_reboot)
804		return -EBUSY;
805
806	if (attr == &sysfs_unregister)
807		bch_cache_set_unregister(c);
808
809	if (attr == &sysfs_stop)
810		bch_cache_set_stop(c);
811
812	if (attr == &sysfs_synchronous) {
813		bool sync = strtoul_or_return(buf);
814
815		if (sync != CACHE_SYNC(&c->cache->sb)) {
816			SET_CACHE_SYNC(&c->cache->sb, sync);
817			bcache_write_super(c);
818		}
819	}
820
821	if (attr == &sysfs_flash_vol_create) {
822		int r;
823		uint64_t v;
824
825		strtoi_h_or_return(buf, v);
826
827		r = bch_flash_dev_create(c, v);
828		if (r)
829			return r;
830	}
831
832	if (attr == &sysfs_clear_stats) {
833		atomic_long_set(&c->writeback_keys_done,	0);
834		atomic_long_set(&c->writeback_keys_failed,	0);
835
836		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
837		bch_cache_accounting_clear(&c->accounting);
838	}
839
840	if (attr == &sysfs_trigger_gc)
841		force_wake_up_gc(c);
842
843	if (attr == &sysfs_prune_cache) {
844		struct shrink_control sc;
845
846		sc.gfp_mask = GFP_KERNEL;
847		sc.nr_to_scan = strtoul_or_return(buf);
848		c->shrink.scan_objects(&c->shrink, &sc);
849	}
850
851	sysfs_strtoul_clamp(congested_read_threshold_us,
852			    c->congested_read_threshold_us,
853			    0, UINT_MAX);
854	sysfs_strtoul_clamp(congested_write_threshold_us,
855			    c->congested_write_threshold_us,
856			    0, UINT_MAX);
857
858	if (attr == &sysfs_errors) {
859		v = __sysfs_match_string(error_actions, -1, buf);
860		if (v < 0)
861			return v;
862
863		c->on_error = v;
864	}
865
866	sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
867
868	/* See count_io_errors() for why 88 */
869	if (attr == &sysfs_io_error_halflife) {
870		unsigned long v = 0;
871		ssize_t ret;
872
873		ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX);
874		if (!ret) {
875			c->error_decay = v / 88;
876			return size;
877		}
878		return ret;
879	}
880
881	if (attr == &sysfs_io_disable) {
882		v = strtoul_or_return(buf);
883		if (v) {
884			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
885					     &c->flags))
886				pr_warn("CACHE_SET_IO_DISABLE already set\n");
887		} else {
888			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
889						&c->flags))
890				pr_warn("CACHE_SET_IO_DISABLE already cleared\n");
891		}
892	}
893
894	sysfs_strtoul_clamp(journal_delay_ms,
895			    c->journal_delay_ms,
896			    0, USHRT_MAX);
897	sysfs_strtoul_bool(verify,		c->verify);
898	sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
899	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
900	sysfs_strtoul_bool(gc_always_rewrite,	c->gc_always_rewrite);
901	sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
902	sysfs_strtoul_bool(copy_gc_enabled,	c->copy_gc_enabled);
903	sysfs_strtoul_bool(idle_max_writeback_rate,
904			   c->idle_max_writeback_rate_enabled);
905
906	/*
907	 * write gc_after_writeback here may overwrite an already set
908	 * BCH_DO_AUTO_GC, it doesn't matter because this flag will be
909	 * set in next chance.
910	 */
911	sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1);
912
913	return size;
914}
915STORE_LOCKED(bch_cache_set)
916
917SHOW(bch_cache_set_internal)
918{
919	struct cache_set *c = container_of(kobj, struct cache_set, internal);
920
921	return bch_cache_set_show(&c->kobj, attr, buf);
922}
923
924STORE(bch_cache_set_internal)
925{
926	struct cache_set *c = container_of(kobj, struct cache_set, internal);
927
928	/* no user space access if system is rebooting */
929	if (bcache_is_reboot)
930		return -EBUSY;
931
932	return bch_cache_set_store(&c->kobj, attr, buf, size);
933}
934
935static void bch_cache_set_internal_release(struct kobject *k)
936{
937}
938
939static struct attribute *bch_cache_set_files[] = {
940	&sysfs_unregister,
941	&sysfs_stop,
942	&sysfs_synchronous,
943	&sysfs_journal_delay_ms,
944	&sysfs_flash_vol_create,
945
946	&sysfs_bucket_size,
947	&sysfs_block_size,
948	&sysfs_tree_depth,
949	&sysfs_root_usage_percent,
950	&sysfs_btree_cache_size,
951	&sysfs_cache_available_percent,
952
953	&sysfs_average_key_size,
954
955	&sysfs_errors,
956	&sysfs_io_error_limit,
957	&sysfs_io_error_halflife,
958	&sysfs_congested,
959	&sysfs_congested_read_threshold_us,
960	&sysfs_congested_write_threshold_us,
961	&sysfs_clear_stats,
962	NULL
963};
964KTYPE(bch_cache_set);
965
966static struct attribute *bch_cache_set_internal_files[] = {
967	&sysfs_active_journal_entries,
968
969	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
970	sysfs_time_stats_attribute_list(btree_split, sec, us)
971	sysfs_time_stats_attribute_list(btree_sort, ms, us)
972	sysfs_time_stats_attribute_list(btree_read, ms, us)
973
974	&sysfs_btree_nodes,
975	&sysfs_btree_used_percent,
976	&sysfs_btree_cache_max_chain,
977
978	&sysfs_bset_tree_stats,
979	&sysfs_cache_read_races,
980	&sysfs_reclaim,
981	&sysfs_reclaimed_journal_buckets,
982	&sysfs_flush_write,
983	&sysfs_writeback_keys_done,
984	&sysfs_writeback_keys_failed,
985
986	&sysfs_trigger_gc,
987	&sysfs_prune_cache,
988#ifdef CONFIG_BCACHE_DEBUG
989	&sysfs_verify,
990	&sysfs_key_merging_disabled,
991	&sysfs_expensive_debug_checks,
992#endif
993	&sysfs_gc_always_rewrite,
994	&sysfs_btree_shrinker_disabled,
995	&sysfs_copy_gc_enabled,
996	&sysfs_idle_max_writeback_rate,
997	&sysfs_gc_after_writeback,
998	&sysfs_io_disable,
999	&sysfs_cutoff_writeback,
1000	&sysfs_cutoff_writeback_sync,
1001	&sysfs_feature_compat,
1002	&sysfs_feature_ro_compat,
1003	&sysfs_feature_incompat,
1004	NULL
1005};
1006KTYPE(bch_cache_set_internal);
1007
1008static int __bch_cache_cmp(const void *l, const void *r)
1009{
1010	cond_resched();
1011	return *((uint16_t *)r) - *((uint16_t *)l);
1012}
1013
1014SHOW(__bch_cache)
1015{
1016	struct cache *ca = container_of(kobj, struct cache, kobj);
1017
1018	sysfs_hprint(bucket_size,	bucket_bytes(ca));
1019	sysfs_hprint(block_size,	block_bytes(ca));
1020	sysfs_print(nbuckets,		ca->sb.nbuckets);
1021	sysfs_print(discard,		ca->discard);
1022	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
1023	sysfs_hprint(btree_written,
1024		     atomic_long_read(&ca->btree_sectors_written) << 9);
1025	sysfs_hprint(metadata_written,
1026		     (atomic_long_read(&ca->meta_sectors_written) +
1027		      atomic_long_read(&ca->btree_sectors_written)) << 9);
1028
1029	sysfs_print(io_errors,
1030		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
1031
1032	if (attr == &sysfs_cache_replacement_policy)
1033		return bch_snprint_string_list(buf, PAGE_SIZE,
1034					       cache_replacement_policies,
1035					       CACHE_REPLACEMENT(&ca->sb));
1036
1037	if (attr == &sysfs_priority_stats) {
1038		struct bucket *b;
1039		size_t n = ca->sb.nbuckets, i;
1040		size_t unused = 0, available = 0, dirty = 0, meta = 0;
1041		uint64_t sum = 0;
1042		/* Compute 31 quantiles */
1043		uint16_t q[31], *p, *cached;
1044		ssize_t ret;
1045
1046		cached = p = vmalloc(array_size(sizeof(uint16_t),
1047						ca->sb.nbuckets));
1048		if (!p)
1049			return -ENOMEM;
1050
1051		mutex_lock(&ca->set->bucket_lock);
1052		for_each_bucket(b, ca) {
1053			if (!GC_SECTORS_USED(b))
1054				unused++;
1055			if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
1056				available++;
1057			if (GC_MARK(b) == GC_MARK_DIRTY)
1058				dirty++;
1059			if (GC_MARK(b) == GC_MARK_METADATA)
1060				meta++;
1061		}
1062
1063		for (i = ca->sb.first_bucket; i < n; i++)
1064			p[i] = ca->buckets[i].prio;
1065		mutex_unlock(&ca->set->bucket_lock);
1066
1067		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
1068
1069		while (n &&
1070		       !cached[n - 1])
1071			--n;
1072
1073		while (cached < p + n &&
1074		       *cached == BTREE_PRIO)
1075			cached++, n--;
1076
1077		for (i = 0; i < n; i++)
1078			sum += INITIAL_PRIO - cached[i];
1079
1080		if (n)
1081			sum = div64_u64(sum, n);
1082
1083		for (i = 0; i < ARRAY_SIZE(q); i++)
1084			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
1085				(ARRAY_SIZE(q) + 1)];
1086
1087		vfree(p);
1088
1089		ret = scnprintf(buf, PAGE_SIZE,
1090				"Unused:		%zu%%\n"
1091				"Clean:		%zu%%\n"
1092				"Dirty:		%zu%%\n"
1093				"Metadata:	%zu%%\n"
1094				"Average:	%llu\n"
1095				"Sectors per Q:	%zu\n"
1096				"Quantiles:	[",
1097				unused * 100 / (size_t) ca->sb.nbuckets,
1098				available * 100 / (size_t) ca->sb.nbuckets,
1099				dirty * 100 / (size_t) ca->sb.nbuckets,
1100				meta * 100 / (size_t) ca->sb.nbuckets, sum,
1101				n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
1102
1103		for (i = 0; i < ARRAY_SIZE(q); i++)
1104			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
1105					 "%u ", q[i]);
1106		ret--;
1107
1108		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
1109
1110		return ret;
1111	}
1112
1113	return 0;
1114}
1115SHOW_LOCKED(bch_cache)
1116
1117STORE(__bch_cache)
1118{
1119	struct cache *ca = container_of(kobj, struct cache, kobj);
1120	ssize_t v;
1121
1122	/* no user space access if system is rebooting */
1123	if (bcache_is_reboot)
1124		return -EBUSY;
1125
1126	if (attr == &sysfs_discard) {
1127		bool v = strtoul_or_return(buf);
1128
1129		if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1130			ca->discard = v;
1131
1132		if (v != CACHE_DISCARD(&ca->sb)) {
1133			SET_CACHE_DISCARD(&ca->sb, v);
1134			bcache_write_super(ca->set);
1135		}
1136	}
1137
1138	if (attr == &sysfs_cache_replacement_policy) {
1139		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
1140		if (v < 0)
1141			return v;
1142
1143		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
1144			mutex_lock(&ca->set->bucket_lock);
1145			SET_CACHE_REPLACEMENT(&ca->sb, v);
1146			mutex_unlock(&ca->set->bucket_lock);
1147
1148			bcache_write_super(ca->set);
1149		}
1150	}
1151
1152	if (attr == &sysfs_clear_stats) {
1153		atomic_long_set(&ca->sectors_written, 0);
1154		atomic_long_set(&ca->btree_sectors_written, 0);
1155		atomic_long_set(&ca->meta_sectors_written, 0);
1156		atomic_set(&ca->io_count, 0);
1157		atomic_set(&ca->io_errors, 0);
1158	}
1159
1160	return size;
1161}
1162STORE_LOCKED(bch_cache)
1163
1164static struct attribute *bch_cache_files[] = {
1165	&sysfs_bucket_size,
1166	&sysfs_block_size,
1167	&sysfs_nbuckets,
1168	&sysfs_priority_stats,
1169	&sysfs_discard,
1170	&sysfs_written,
1171	&sysfs_btree_written,
1172	&sysfs_metadata_written,
1173	&sysfs_io_errors,
1174	&sysfs_clear_stats,
1175	&sysfs_cache_replacement_policy,
1176	NULL
1177};
1178KTYPE(bch_cache);
1179