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);
120rw_attribute(writeback_consider_fragment);
121
122rw_attribute(writeback_rate_update_seconds);
123rw_attribute(writeback_rate_i_term_inverse);
124rw_attribute(writeback_rate_p_term_inverse);
125rw_attribute(writeback_rate_fp_term_low);
126rw_attribute(writeback_rate_fp_term_mid);
127rw_attribute(writeback_rate_fp_term_high);
128rw_attribute(writeback_rate_minimum);
129read_attribute(writeback_rate_debug);
130
131read_attribute(stripe_size);
132read_attribute(partial_stripes_expensive);
133
134rw_attribute(synchronous);
135rw_attribute(journal_delay_ms);
136rw_attribute(io_disable);
137rw_attribute(discard);
138rw_attribute(running);
139rw_attribute(label);
140rw_attribute(errors);
141rw_attribute(io_error_limit);
142rw_attribute(io_error_halflife);
143rw_attribute(verify);
144rw_attribute(bypass_torture_test);
145rw_attribute(key_merging_disabled);
146rw_attribute(gc_always_rewrite);
147rw_attribute(expensive_debug_checks);
148rw_attribute(cache_replacement_policy);
149rw_attribute(btree_shrinker_disabled);
150rw_attribute(copy_gc_enabled);
151rw_attribute(idle_max_writeback_rate);
152rw_attribute(gc_after_writeback);
153rw_attribute(size);
154
155static ssize_t bch_snprint_string_list(char *buf,
156				       size_t size,
157				       const char * const list[],
158				       size_t selected)
159{
160	char *out = buf;
161	size_t i;
162
163	for (i = 0; list[i]; i++)
164		out += scnprintf(out, buf + size - out,
165				i == selected ? "[%s] " : "%s ", list[i]);
166
167	out[-1] = '\n';
168	return out - buf;
169}
170
171SHOW(__bch_cached_dev)
172{
173	struct cached_dev *dc = container_of(kobj, struct cached_dev,
174					     disk.kobj);
175	char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
176	int wb = dc->writeback_running;
177
178#define var(stat)		(dc->stat)
179
180	if (attr == &sysfs_cache_mode)
181		return bch_snprint_string_list(buf, PAGE_SIZE,
182					       bch_cache_modes,
183					       BDEV_CACHE_MODE(&dc->sb));
184
185	if (attr == &sysfs_readahead_cache_policy)
186		return bch_snprint_string_list(buf, PAGE_SIZE,
187					      bch_reada_cache_policies,
188					      dc->cache_readahead_policy);
189
190	if (attr == &sysfs_stop_when_cache_set_failed)
191		return bch_snprint_string_list(buf, PAGE_SIZE,
192					       bch_stop_on_failure_modes,
193					       dc->stop_when_cache_set_failed);
194
195
196	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
197	var_printf(verify,		"%i");
198	var_printf(bypass_torture_test,	"%i");
199	var_printf(writeback_metadata,	"%i");
200	var_printf(writeback_running,	"%i");
201	var_printf(writeback_consider_fragment,	"%i");
202	var_print(writeback_delay);
203	var_print(writeback_percent);
204	sysfs_hprint(writeback_rate,
205		     wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
206	sysfs_printf(io_errors,		"%i", atomic_read(&dc->io_errors));
207	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
208	sysfs_printf(io_disable,	"%i", dc->io_disable);
209	var_print(writeback_rate_update_seconds);
210	var_print(writeback_rate_i_term_inverse);
211	var_print(writeback_rate_p_term_inverse);
212	var_print(writeback_rate_fp_term_low);
213	var_print(writeback_rate_fp_term_mid);
214	var_print(writeback_rate_fp_term_high);
215	var_print(writeback_rate_minimum);
216
217	if (attr == &sysfs_writeback_rate_debug) {
218		char rate[20];
219		char dirty[20];
220		char target[20];
221		char proportional[20];
222		char integral[20];
223		char change[20];
224		s64 next_io;
225
226		/*
227		 * Except for dirty and target, other values should
228		 * be 0 if writeback is not running.
229		 */
230		bch_hprint(rate,
231			   wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
232			      : 0);
233		bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
234		bch_hprint(target, dc->writeback_rate_target << 9);
235		bch_hprint(proportional,
236			   wb ? dc->writeback_rate_proportional << 9 : 0);
237		bch_hprint(integral,
238			   wb ? dc->writeback_rate_integral_scaled << 9 : 0);
239		bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
240		next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
241					 NSEC_PER_MSEC) : 0;
242
243		return sprintf(buf,
244			       "rate:\t\t%s/sec\n"
245			       "dirty:\t\t%s\n"
246			       "target:\t\t%s\n"
247			       "proportional:\t%s\n"
248			       "integral:\t%s\n"
249			       "change:\t\t%s/sec\n"
250			       "next io:\t%llims\n",
251			       rate, dirty, target, proportional,
252			       integral, change, next_io);
253	}
254
255	sysfs_hprint(dirty_data,
256		     bcache_dev_sectors_dirty(&dc->disk) << 9);
257
258	sysfs_hprint(stripe_size,	 ((uint64_t)dc->disk.stripe_size) << 9);
259	var_printf(partial_stripes_expensive,	"%u");
260
261	var_hprint(sequential_cutoff);
262
263	sysfs_print(running,		atomic_read(&dc->running));
264	sysfs_print(state,		states[BDEV_STATE(&dc->sb)]);
265
266	if (attr == &sysfs_label) {
267		memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
268		buf[SB_LABEL_SIZE + 1] = '\0';
269		strcat(buf, "\n");
270		return strlen(buf);
271	}
272
273	if (attr == &sysfs_backing_dev_name) {
274		snprintf(buf, BDEVNAME_SIZE + 1, "%pg", dc->bdev);
275		strcat(buf, "\n");
276		return strlen(buf);
277	}
278
279	if (attr == &sysfs_backing_dev_uuid) {
280		/* convert binary uuid into 36-byte string plus '\0' */
281		snprintf(buf, 36+1, "%pU", dc->sb.uuid);
282		strcat(buf, "\n");
283		return strlen(buf);
284	}
285
286#undef var
287	return 0;
288}
289SHOW_LOCKED(bch_cached_dev)
290
291STORE(__cached_dev)
292{
293	struct cached_dev *dc = container_of(kobj, struct cached_dev,
294					     disk.kobj);
295	ssize_t v;
296	struct cache_set *c;
297	struct kobj_uevent_env *env;
298
299	/* no user space access if system is rebooting */
300	if (bcache_is_reboot)
301		return -EBUSY;
302
303#define d_strtoul(var)		sysfs_strtoul(var, dc->var)
304#define d_strtoul_nonzero(var)	sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
305#define d_strtoi_h(var)		sysfs_hatoi(var, dc->var)
306
307	sysfs_strtoul(data_csum,	dc->disk.data_csum);
308	d_strtoul(verify);
309	sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test);
310	sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata);
311	sysfs_strtoul_bool(writeback_running, dc->writeback_running);
312	sysfs_strtoul_bool(writeback_consider_fragment, dc->writeback_consider_fragment);
313	sysfs_strtoul_clamp(writeback_delay, dc->writeback_delay, 0, UINT_MAX);
314
315	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent,
316			    0, bch_cutoff_writeback);
317
318	if (attr == &sysfs_writeback_rate) {
319		ssize_t ret;
320		long int v = atomic_long_read(&dc->writeback_rate.rate);
321
322		ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
323
324		if (!ret) {
325			atomic_long_set(&dc->writeback_rate.rate, v);
326			ret = size;
327		}
328
329		return ret;
330	}
331
332	sysfs_strtoul_clamp(writeback_rate_update_seconds,
333			    dc->writeback_rate_update_seconds,
334			    1, WRITEBACK_RATE_UPDATE_SECS_MAX);
335	sysfs_strtoul_clamp(writeback_rate_i_term_inverse,
336			    dc->writeback_rate_i_term_inverse,
337			    1, UINT_MAX);
338	sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
339			    dc->writeback_rate_p_term_inverse,
340			    1, UINT_MAX);
341	sysfs_strtoul_clamp(writeback_rate_fp_term_low,
342			    dc->writeback_rate_fp_term_low,
343			    1, dc->writeback_rate_fp_term_mid - 1);
344	sysfs_strtoul_clamp(writeback_rate_fp_term_mid,
345			    dc->writeback_rate_fp_term_mid,
346			    dc->writeback_rate_fp_term_low + 1,
347			    dc->writeback_rate_fp_term_high - 1);
348	sysfs_strtoul_clamp(writeback_rate_fp_term_high,
349			    dc->writeback_rate_fp_term_high,
350			    dc->writeback_rate_fp_term_mid + 1, UINT_MAX);
351	sysfs_strtoul_clamp(writeback_rate_minimum,
352			    dc->writeback_rate_minimum,
353			    1, UINT_MAX);
354
355	sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);
356
357	if (attr == &sysfs_io_disable) {
358		int v = strtoul_or_return(buf);
359
360		dc->io_disable = v ? 1 : 0;
361	}
362
363	sysfs_strtoul_clamp(sequential_cutoff,
364			    dc->sequential_cutoff,
365			    0, UINT_MAX);
366
367	if (attr == &sysfs_clear_stats)
368		bch_cache_accounting_clear(&dc->accounting);
369
370	if (attr == &sysfs_running &&
371	    strtoul_or_return(buf)) {
372		v = bch_cached_dev_run(dc);
373		if (v)
374			return v;
375	}
376
377	if (attr == &sysfs_cache_mode) {
378		v = __sysfs_match_string(bch_cache_modes, -1, buf);
379		if (v < 0)
380			return v;
381
382		if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
383			SET_BDEV_CACHE_MODE(&dc->sb, v);
384			bch_write_bdev_super(dc, NULL);
385		}
386	}
387
388	if (attr == &sysfs_readahead_cache_policy) {
389		v = __sysfs_match_string(bch_reada_cache_policies, -1, buf);
390		if (v < 0)
391			return v;
392
393		if ((unsigned int) v != dc->cache_readahead_policy)
394			dc->cache_readahead_policy = v;
395	}
396
397	if (attr == &sysfs_stop_when_cache_set_failed) {
398		v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
399		if (v < 0)
400			return v;
401
402		dc->stop_when_cache_set_failed = v;
403	}
404
405	if (attr == &sysfs_label) {
406		if (size > SB_LABEL_SIZE)
407			return -EINVAL;
408		memcpy(dc->sb.label, buf, size);
409		if (size < SB_LABEL_SIZE)
410			dc->sb.label[size] = '\0';
411		if (size && dc->sb.label[size - 1] == '\n')
412			dc->sb.label[size - 1] = '\0';
413		bch_write_bdev_super(dc, NULL);
414		if (dc->disk.c) {
415			memcpy(dc->disk.c->uuids[dc->disk.id].label,
416			       buf, SB_LABEL_SIZE);
417			bch_uuid_write(dc->disk.c);
418		}
419		env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
420		if (!env)
421			return -ENOMEM;
422		add_uevent_var(env, "DRIVER=bcache");
423		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid);
424		add_uevent_var(env, "CACHED_LABEL=%s", buf);
425		kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj,
426				   KOBJ_CHANGE,
427				   env->envp);
428		kfree(env);
429	}
430
431	if (attr == &sysfs_attach) {
432		uint8_t		set_uuid[16];
433
434		if (bch_parse_uuid(buf, set_uuid) < 16)
435			return -EINVAL;
436
437		v = -ENOENT;
438		list_for_each_entry(c, &bch_cache_sets, list) {
439			v = bch_cached_dev_attach(dc, c, set_uuid);
440			if (!v)
441				return size;
442		}
443		if (v == -ENOENT)
444			pr_err("Can't attach %s: cache set not found\n", buf);
445		return v;
446	}
447
448	if (attr == &sysfs_detach && dc->disk.c)
449		bch_cached_dev_detach(dc);
450
451	if (attr == &sysfs_stop)
452		bcache_device_stop(&dc->disk);
453
454	return size;
455}
456
457STORE(bch_cached_dev)
458{
459	struct cached_dev *dc = container_of(kobj, struct cached_dev,
460					     disk.kobj);
461
462	/* no user space access if system is rebooting */
463	if (bcache_is_reboot)
464		return -EBUSY;
465
466	mutex_lock(&bch_register_lock);
467	size = __cached_dev_store(kobj, attr, buf, size);
468
469	if (attr == &sysfs_writeback_running) {
470		/* dc->writeback_running changed in __cached_dev_store() */
471		if (IS_ERR_OR_NULL(dc->writeback_thread)) {
472			/*
473			 * reject setting it to 1 via sysfs if writeback
474			 * kthread is not created yet.
475			 */
476			if (dc->writeback_running) {
477				dc->writeback_running = false;
478				pr_err("%s: failed to run non-existent writeback thread\n",
479						dc->disk.disk->disk_name);
480			}
481		} else
482			/*
483			 * writeback kthread will check if dc->writeback_running
484			 * is true or false.
485			 */
486			bch_writeback_queue(dc);
487	}
488
489	/*
490	 * Only set BCACHE_DEV_WB_RUNNING when cached device attached to
491	 * a cache set, otherwise it doesn't make sense.
492	 */
493	if (attr == &sysfs_writeback_percent)
494		if ((dc->disk.c != NULL) &&
495		    (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)))
496			schedule_delayed_work(&dc->writeback_rate_update,
497				      dc->writeback_rate_update_seconds * HZ);
498
499	mutex_unlock(&bch_register_lock);
500	return size;
501}
502
503static struct attribute *bch_cached_dev_attrs[] = {
504	&sysfs_attach,
505	&sysfs_detach,
506	&sysfs_stop,
507#if 0
508	&sysfs_data_csum,
509#endif
510	&sysfs_cache_mode,
511	&sysfs_readahead_cache_policy,
512	&sysfs_stop_when_cache_set_failed,
513	&sysfs_writeback_metadata,
514	&sysfs_writeback_running,
515	&sysfs_writeback_delay,
516	&sysfs_writeback_percent,
517	&sysfs_writeback_rate,
518	&sysfs_writeback_consider_fragment,
519	&sysfs_writeback_rate_update_seconds,
520	&sysfs_writeback_rate_i_term_inverse,
521	&sysfs_writeback_rate_p_term_inverse,
522	&sysfs_writeback_rate_fp_term_low,
523	&sysfs_writeback_rate_fp_term_mid,
524	&sysfs_writeback_rate_fp_term_high,
525	&sysfs_writeback_rate_minimum,
526	&sysfs_writeback_rate_debug,
527	&sysfs_io_errors,
528	&sysfs_io_error_limit,
529	&sysfs_io_disable,
530	&sysfs_dirty_data,
531	&sysfs_stripe_size,
532	&sysfs_partial_stripes_expensive,
533	&sysfs_sequential_cutoff,
534	&sysfs_clear_stats,
535	&sysfs_running,
536	&sysfs_state,
537	&sysfs_label,
538#ifdef CONFIG_BCACHE_DEBUG
539	&sysfs_verify,
540	&sysfs_bypass_torture_test,
541#endif
542	&sysfs_backing_dev_name,
543	&sysfs_backing_dev_uuid,
544	NULL
545};
546ATTRIBUTE_GROUPS(bch_cached_dev);
547KTYPE(bch_cached_dev);
548
549SHOW(bch_flash_dev)
550{
551	struct bcache_device *d = container_of(kobj, struct bcache_device,
552					       kobj);
553	struct uuid_entry *u = &d->c->uuids[d->id];
554
555	sysfs_printf(data_csum,	"%i", d->data_csum);
556	sysfs_hprint(size,	u->sectors << 9);
557
558	if (attr == &sysfs_label) {
559		memcpy(buf, u->label, SB_LABEL_SIZE);
560		buf[SB_LABEL_SIZE + 1] = '\0';
561		strcat(buf, "\n");
562		return strlen(buf);
563	}
564
565	return 0;
566}
567
568STORE(__bch_flash_dev)
569{
570	struct bcache_device *d = container_of(kobj, struct bcache_device,
571					       kobj);
572	struct uuid_entry *u = &d->c->uuids[d->id];
573
574	/* no user space access if system is rebooting */
575	if (bcache_is_reboot)
576		return -EBUSY;
577
578	sysfs_strtoul(data_csum,	d->data_csum);
579
580	if (attr == &sysfs_size) {
581		uint64_t v;
582
583		strtoi_h_or_return(buf, v);
584
585		u->sectors = v >> 9;
586		bch_uuid_write(d->c);
587		set_capacity(d->disk, u->sectors);
588	}
589
590	if (attr == &sysfs_label) {
591		memcpy(u->label, buf, SB_LABEL_SIZE);
592		bch_uuid_write(d->c);
593	}
594
595	if (attr == &sysfs_unregister) {
596		set_bit(BCACHE_DEV_DETACHING, &d->flags);
597		bcache_device_stop(d);
598	}
599
600	return size;
601}
602STORE_LOCKED(bch_flash_dev)
603
604static struct attribute *bch_flash_dev_attrs[] = {
605	&sysfs_unregister,
606#if 0
607	&sysfs_data_csum,
608#endif
609	&sysfs_label,
610	&sysfs_size,
611	NULL
612};
613ATTRIBUTE_GROUPS(bch_flash_dev);
614KTYPE(bch_flash_dev);
615
616struct bset_stats_op {
617	struct btree_op op;
618	size_t nodes;
619	struct bset_stats stats;
620};
621
622static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b)
623{
624	struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op);
625
626	op->nodes++;
627	bch_btree_keys_stats(&b->keys, &op->stats);
628
629	return MAP_CONTINUE;
630}
631
632static int bch_bset_print_stats(struct cache_set *c, char *buf)
633{
634	struct bset_stats_op op;
635	int ret;
636
637	memset(&op, 0, sizeof(op));
638	bch_btree_op_init(&op.op, -1);
639
640	ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats);
641	if (ret < 0)
642		return ret;
643
644	return snprintf(buf, PAGE_SIZE,
645			"btree nodes:		%zu\n"
646			"written sets:		%zu\n"
647			"unwritten sets:		%zu\n"
648			"written key bytes:	%zu\n"
649			"unwritten key bytes:	%zu\n"
650			"floats:			%zu\n"
651			"failed:			%zu\n",
652			op.nodes,
653			op.stats.sets_written, op.stats.sets_unwritten,
654			op.stats.bytes_written, op.stats.bytes_unwritten,
655			op.stats.floats, op.stats.failed);
656}
657
658static unsigned int bch_root_usage(struct cache_set *c)
659{
660	unsigned int bytes = 0;
661	struct bkey *k;
662	struct btree *b;
663	struct btree_iter iter;
664
665	goto lock_root;
666
667	do {
668		rw_unlock(false, b);
669lock_root:
670		b = c->root;
671		rw_lock(false, b, b->level);
672	} while (b != c->root);
673
674	for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
675		bytes += bkey_bytes(k);
676
677	rw_unlock(false, b);
678
679	return (bytes * 100) / btree_bytes(c);
680}
681
682static size_t bch_cache_size(struct cache_set *c)
683{
684	size_t ret = 0;
685	struct btree *b;
686
687	mutex_lock(&c->bucket_lock);
688	list_for_each_entry(b, &c->btree_cache, list)
689		ret += 1 << (b->keys.page_order + PAGE_SHIFT);
690
691	mutex_unlock(&c->bucket_lock);
692	return ret;
693}
694
695static unsigned int bch_cache_max_chain(struct cache_set *c)
696{
697	unsigned int ret = 0;
698	struct hlist_head *h;
699
700	mutex_lock(&c->bucket_lock);
701
702	for (h = c->bucket_hash;
703	     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
704	     h++) {
705		ret = max(ret, hlist_count_nodes(h));
706	}
707
708	mutex_unlock(&c->bucket_lock);
709	return ret;
710}
711
712static unsigned int bch_btree_used(struct cache_set *c)
713{
714	return div64_u64(c->gc_stats.key_bytes * 100,
715			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
716}
717
718static unsigned int bch_average_key_size(struct cache_set *c)
719{
720	return c->gc_stats.nkeys
721		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
722		: 0;
723}
724
725SHOW(__bch_cache_set)
726{
727	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
728
729	sysfs_print(synchronous,		CACHE_SYNC(&c->cache->sb));
730	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
731	sysfs_hprint(bucket_size,		bucket_bytes(c->cache));
732	sysfs_hprint(block_size,		block_bytes(c->cache));
733	sysfs_print(tree_depth,			c->root->level);
734	sysfs_print(root_usage_percent,		bch_root_usage(c));
735
736	sysfs_hprint(btree_cache_size,		bch_cache_size(c));
737	sysfs_print(btree_cache_max_chain,	bch_cache_max_chain(c));
738	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
739
740	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
741	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
742	sysfs_print_time_stats(&c->sort.time,		btree_sort, ms, us);
743	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
744
745	sysfs_print(btree_used_percent,	bch_btree_used(c));
746	sysfs_print(btree_nodes,	c->gc_stats.nodes);
747	sysfs_hprint(average_key_size,	bch_average_key_size(c));
748
749	sysfs_print(cache_read_races,
750		    atomic_long_read(&c->cache_read_races));
751
752	sysfs_print(reclaim,
753		    atomic_long_read(&c->reclaim));
754
755	sysfs_print(reclaimed_journal_buckets,
756		    atomic_long_read(&c->reclaimed_journal_buckets));
757
758	sysfs_print(flush_write,
759		    atomic_long_read(&c->flush_write));
760
761	sysfs_print(writeback_keys_done,
762		    atomic_long_read(&c->writeback_keys_done));
763	sysfs_print(writeback_keys_failed,
764		    atomic_long_read(&c->writeback_keys_failed));
765
766	if (attr == &sysfs_errors)
767		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
768					       c->on_error);
769
770	/* See count_io_errors for why 88 */
771	sysfs_print(io_error_halflife,	c->error_decay * 88);
772	sysfs_print(io_error_limit,	c->error_limit);
773
774	sysfs_hprint(congested,
775		     ((uint64_t) bch_get_congested(c)) << 9);
776	sysfs_print(congested_read_threshold_us,
777		    c->congested_read_threshold_us);
778	sysfs_print(congested_write_threshold_us,
779		    c->congested_write_threshold_us);
780
781	sysfs_print(cutoff_writeback, bch_cutoff_writeback);
782	sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync);
783
784	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
785	sysfs_printf(verify,			"%i", c->verify);
786	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
787	sysfs_printf(expensive_debug_checks,
788		     "%i", c->expensive_debug_checks);
789	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
790	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
791	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
792	sysfs_printf(idle_max_writeback_rate,	"%i",
793		     c->idle_max_writeback_rate_enabled);
794	sysfs_printf(gc_after_writeback,	"%i", c->gc_after_writeback);
795	sysfs_printf(io_disable,		"%i",
796		     test_bit(CACHE_SET_IO_DISABLE, &c->flags));
797
798	if (attr == &sysfs_bset_tree_stats)
799		return bch_bset_print_stats(c, buf);
800
801	if (attr == &sysfs_feature_compat)
802		return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE);
803	if (attr == &sysfs_feature_ro_compat)
804		return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE);
805	if (attr == &sysfs_feature_incompat)
806		return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE);
807
808	return 0;
809}
810SHOW_LOCKED(bch_cache_set)
811
812STORE(__bch_cache_set)
813{
814	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
815	ssize_t v;
816
817	/* no user space access if system is rebooting */
818	if (bcache_is_reboot)
819		return -EBUSY;
820
821	if (attr == &sysfs_unregister)
822		bch_cache_set_unregister(c);
823
824	if (attr == &sysfs_stop)
825		bch_cache_set_stop(c);
826
827	if (attr == &sysfs_synchronous) {
828		bool sync = strtoul_or_return(buf);
829
830		if (sync != CACHE_SYNC(&c->cache->sb)) {
831			SET_CACHE_SYNC(&c->cache->sb, sync);
832			bcache_write_super(c);
833		}
834	}
835
836	if (attr == &sysfs_flash_vol_create) {
837		int r;
838		uint64_t v;
839
840		strtoi_h_or_return(buf, v);
841
842		r = bch_flash_dev_create(c, v);
843		if (r)
844			return r;
845	}
846
847	if (attr == &sysfs_clear_stats) {
848		atomic_long_set(&c->writeback_keys_done,	0);
849		atomic_long_set(&c->writeback_keys_failed,	0);
850
851		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
852		bch_cache_accounting_clear(&c->accounting);
853	}
854
855	if (attr == &sysfs_trigger_gc)
856		force_wake_up_gc(c);
857
858	if (attr == &sysfs_prune_cache) {
859		struct shrink_control sc;
860
861		sc.gfp_mask = GFP_KERNEL;
862		sc.nr_to_scan = strtoul_or_return(buf);
863		if (c->shrink)
864			c->shrink->scan_objects(c->shrink, &sc);
865	}
866
867	sysfs_strtoul_clamp(congested_read_threshold_us,
868			    c->congested_read_threshold_us,
869			    0, UINT_MAX);
870	sysfs_strtoul_clamp(congested_write_threshold_us,
871			    c->congested_write_threshold_us,
872			    0, UINT_MAX);
873
874	if (attr == &sysfs_errors) {
875		v = __sysfs_match_string(error_actions, -1, buf);
876		if (v < 0)
877			return v;
878
879		c->on_error = v;
880	}
881
882	sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
883
884	/* See count_io_errors() for why 88 */
885	if (attr == &sysfs_io_error_halflife) {
886		unsigned long v = 0;
887		ssize_t ret;
888
889		ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX);
890		if (!ret) {
891			c->error_decay = v / 88;
892			return size;
893		}
894		return ret;
895	}
896
897	if (attr == &sysfs_io_disable) {
898		v = strtoul_or_return(buf);
899		if (v) {
900			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
901					     &c->flags))
902				pr_warn("CACHE_SET_IO_DISABLE already set\n");
903		} else {
904			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
905						&c->flags))
906				pr_warn("CACHE_SET_IO_DISABLE already cleared\n");
907		}
908	}
909
910	sysfs_strtoul_clamp(journal_delay_ms,
911			    c->journal_delay_ms,
912			    0, USHRT_MAX);
913	sysfs_strtoul_bool(verify,		c->verify);
914	sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
915	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
916	sysfs_strtoul_bool(gc_always_rewrite,	c->gc_always_rewrite);
917	sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
918	sysfs_strtoul_bool(copy_gc_enabled,	c->copy_gc_enabled);
919	sysfs_strtoul_bool(idle_max_writeback_rate,
920			   c->idle_max_writeback_rate_enabled);
921
922	/*
923	 * write gc_after_writeback here may overwrite an already set
924	 * BCH_DO_AUTO_GC, it doesn't matter because this flag will be
925	 * set in next chance.
926	 */
927	sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1);
928
929	return size;
930}
931STORE_LOCKED(bch_cache_set)
932
933SHOW(bch_cache_set_internal)
934{
935	struct cache_set *c = container_of(kobj, struct cache_set, internal);
936
937	return bch_cache_set_show(&c->kobj, attr, buf);
938}
939
940STORE(bch_cache_set_internal)
941{
942	struct cache_set *c = container_of(kobj, struct cache_set, internal);
943
944	/* no user space access if system is rebooting */
945	if (bcache_is_reboot)
946		return -EBUSY;
947
948	return bch_cache_set_store(&c->kobj, attr, buf, size);
949}
950
951static void bch_cache_set_internal_release(struct kobject *k)
952{
953}
954
955static struct attribute *bch_cache_set_attrs[] = {
956	&sysfs_unregister,
957	&sysfs_stop,
958	&sysfs_synchronous,
959	&sysfs_journal_delay_ms,
960	&sysfs_flash_vol_create,
961
962	&sysfs_bucket_size,
963	&sysfs_block_size,
964	&sysfs_tree_depth,
965	&sysfs_root_usage_percent,
966	&sysfs_btree_cache_size,
967	&sysfs_cache_available_percent,
968
969	&sysfs_average_key_size,
970
971	&sysfs_errors,
972	&sysfs_io_error_limit,
973	&sysfs_io_error_halflife,
974	&sysfs_congested,
975	&sysfs_congested_read_threshold_us,
976	&sysfs_congested_write_threshold_us,
977	&sysfs_clear_stats,
978	NULL
979};
980ATTRIBUTE_GROUPS(bch_cache_set);
981KTYPE(bch_cache_set);
982
983static struct attribute *bch_cache_set_internal_attrs[] = {
984	&sysfs_active_journal_entries,
985
986	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
987	sysfs_time_stats_attribute_list(btree_split, sec, us)
988	sysfs_time_stats_attribute_list(btree_sort, ms, us)
989	sysfs_time_stats_attribute_list(btree_read, ms, us)
990
991	&sysfs_btree_nodes,
992	&sysfs_btree_used_percent,
993	&sysfs_btree_cache_max_chain,
994
995	&sysfs_bset_tree_stats,
996	&sysfs_cache_read_races,
997	&sysfs_reclaim,
998	&sysfs_reclaimed_journal_buckets,
999	&sysfs_flush_write,
1000	&sysfs_writeback_keys_done,
1001	&sysfs_writeback_keys_failed,
1002
1003	&sysfs_trigger_gc,
1004	&sysfs_prune_cache,
1005#ifdef CONFIG_BCACHE_DEBUG
1006	&sysfs_verify,
1007	&sysfs_key_merging_disabled,
1008	&sysfs_expensive_debug_checks,
1009#endif
1010	&sysfs_gc_always_rewrite,
1011	&sysfs_btree_shrinker_disabled,
1012	&sysfs_copy_gc_enabled,
1013	&sysfs_idle_max_writeback_rate,
1014	&sysfs_gc_after_writeback,
1015	&sysfs_io_disable,
1016	&sysfs_cutoff_writeback,
1017	&sysfs_cutoff_writeback_sync,
1018	&sysfs_feature_compat,
1019	&sysfs_feature_ro_compat,
1020	&sysfs_feature_incompat,
1021	NULL
1022};
1023ATTRIBUTE_GROUPS(bch_cache_set_internal);
1024KTYPE(bch_cache_set_internal);
1025
1026static int __bch_cache_cmp(const void *l, const void *r)
1027{
1028	cond_resched();
1029	return *((uint16_t *)r) - *((uint16_t *)l);
1030}
1031
1032SHOW(__bch_cache)
1033{
1034	struct cache *ca = container_of(kobj, struct cache, kobj);
1035
1036	sysfs_hprint(bucket_size,	bucket_bytes(ca));
1037	sysfs_hprint(block_size,	block_bytes(ca));
1038	sysfs_print(nbuckets,		ca->sb.nbuckets);
1039	sysfs_print(discard,		ca->discard);
1040	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
1041	sysfs_hprint(btree_written,
1042		     atomic_long_read(&ca->btree_sectors_written) << 9);
1043	sysfs_hprint(metadata_written,
1044		     (atomic_long_read(&ca->meta_sectors_written) +
1045		      atomic_long_read(&ca->btree_sectors_written)) << 9);
1046
1047	sysfs_print(io_errors,
1048		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
1049
1050	if (attr == &sysfs_cache_replacement_policy)
1051		return bch_snprint_string_list(buf, PAGE_SIZE,
1052					       cache_replacement_policies,
1053					       CACHE_REPLACEMENT(&ca->sb));
1054
1055	if (attr == &sysfs_priority_stats) {
1056		struct bucket *b;
1057		size_t n = ca->sb.nbuckets, i;
1058		size_t unused = 0, available = 0, dirty = 0, meta = 0;
1059		uint64_t sum = 0;
1060		/* Compute 31 quantiles */
1061		uint16_t q[31], *p, *cached;
1062		ssize_t ret;
1063
1064		cached = p = vmalloc(array_size(sizeof(uint16_t),
1065						ca->sb.nbuckets));
1066		if (!p)
1067			return -ENOMEM;
1068
1069		mutex_lock(&ca->set->bucket_lock);
1070		for_each_bucket(b, ca) {
1071			if (!GC_SECTORS_USED(b))
1072				unused++;
1073			if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
1074				available++;
1075			if (GC_MARK(b) == GC_MARK_DIRTY)
1076				dirty++;
1077			if (GC_MARK(b) == GC_MARK_METADATA)
1078				meta++;
1079		}
1080
1081		for (i = ca->sb.first_bucket; i < n; i++)
1082			p[i] = ca->buckets[i].prio;
1083		mutex_unlock(&ca->set->bucket_lock);
1084
1085		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
1086
1087		while (n &&
1088		       !cached[n - 1])
1089			--n;
1090
1091		while (cached < p + n &&
1092		       *cached == BTREE_PRIO) {
1093			cached++;
1094			n--;
1095		}
1096
1097		for (i = 0; i < n; i++)
1098			sum += INITIAL_PRIO - cached[i];
1099
1100		if (n)
1101			sum = div64_u64(sum, n);
1102
1103		for (i = 0; i < ARRAY_SIZE(q); i++)
1104			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
1105				(ARRAY_SIZE(q) + 1)];
1106
1107		vfree(p);
1108
1109		ret = sysfs_emit(buf,
1110				 "Unused:		%zu%%\n"
1111				 "Clean:		%zu%%\n"
1112				 "Dirty:		%zu%%\n"
1113				 "Metadata:	%zu%%\n"
1114				 "Average:	%llu\n"
1115				 "Sectors per Q:	%zu\n"
1116				 "Quantiles:	[",
1117				 unused * 100 / (size_t) ca->sb.nbuckets,
1118				 available * 100 / (size_t) ca->sb.nbuckets,
1119				 dirty * 100 / (size_t) ca->sb.nbuckets,
1120				 meta * 100 / (size_t) ca->sb.nbuckets, sum,
1121				 n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
1122
1123		for (i = 0; i < ARRAY_SIZE(q); i++)
1124			ret += sysfs_emit_at(buf, ret, "%u ", q[i]);
1125		ret--;
1126
1127		ret += sysfs_emit_at(buf, ret, "]\n");
1128
1129		return ret;
1130	}
1131
1132	return 0;
1133}
1134SHOW_LOCKED(bch_cache)
1135
1136STORE(__bch_cache)
1137{
1138	struct cache *ca = container_of(kobj, struct cache, kobj);
1139	ssize_t v;
1140
1141	/* no user space access if system is rebooting */
1142	if (bcache_is_reboot)
1143		return -EBUSY;
1144
1145	if (attr == &sysfs_discard) {
1146		bool v = strtoul_or_return(buf);
1147
1148		if (bdev_max_discard_sectors(ca->bdev))
1149			ca->discard = v;
1150
1151		if (v != CACHE_DISCARD(&ca->sb)) {
1152			SET_CACHE_DISCARD(&ca->sb, v);
1153			bcache_write_super(ca->set);
1154		}
1155	}
1156
1157	if (attr == &sysfs_cache_replacement_policy) {
1158		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
1159		if (v < 0)
1160			return v;
1161
1162		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
1163			mutex_lock(&ca->set->bucket_lock);
1164			SET_CACHE_REPLACEMENT(&ca->sb, v);
1165			mutex_unlock(&ca->set->bucket_lock);
1166
1167			bcache_write_super(ca->set);
1168		}
1169	}
1170
1171	if (attr == &sysfs_clear_stats) {
1172		atomic_long_set(&ca->sectors_written, 0);
1173		atomic_long_set(&ca->btree_sectors_written, 0);
1174		atomic_long_set(&ca->meta_sectors_written, 0);
1175		atomic_set(&ca->io_count, 0);
1176		atomic_set(&ca->io_errors, 0);
1177	}
1178
1179	return size;
1180}
1181STORE_LOCKED(bch_cache)
1182
1183static struct attribute *bch_cache_attrs[] = {
1184	&sysfs_bucket_size,
1185	&sysfs_block_size,
1186	&sysfs_nbuckets,
1187	&sysfs_priority_stats,
1188	&sysfs_discard,
1189	&sysfs_written,
1190	&sysfs_btree_written,
1191	&sysfs_metadata_written,
1192	&sysfs_io_errors,
1193	&sysfs_clear_stats,
1194	&sysfs_cache_replacement_policy,
1195	NULL
1196};
1197ATTRIBUTE_GROUPS(bch_cache);
1198KTYPE(bch_cache);
1199