xref: /openbmc/linux/drivers/md/bcache/sysfs.c (revision be122522)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * bcache sysfs interfaces
4  *
5  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6  * Copyright 2012 Google, Inc.
7  */
8 
9 #include "bcache.h"
10 #include "sysfs.h"
11 #include "btree.h"
12 #include "request.h"
13 #include "writeback.h"
14 
15 #include <linux/blkdev.h>
16 #include <linux/sort.h>
17 #include <linux/sched/clock.h>
18 
19 extern bool bcache_is_reboot;
20 
21 /* Default is 0 ("writethrough") */
22 static const char * const bch_cache_modes[] = {
23 	"writethrough",
24 	"writeback",
25 	"writearound",
26 	"none",
27 	NULL
28 };
29 
30 /* Default is 0 ("auto") */
31 static const char * const bch_stop_on_failure_modes[] = {
32 	"auto",
33 	"always",
34 	NULL
35 };
36 
37 static const char * const cache_replacement_policies[] = {
38 	"lru",
39 	"fifo",
40 	"random",
41 	NULL
42 };
43 
44 static const char * const error_actions[] = {
45 	"unregister",
46 	"panic",
47 	NULL
48 };
49 
50 write_attribute(attach);
51 write_attribute(detach);
52 write_attribute(unregister);
53 write_attribute(stop);
54 write_attribute(clear_stats);
55 write_attribute(trigger_gc);
56 write_attribute(prune_cache);
57 write_attribute(flash_vol_create);
58 
59 read_attribute(bucket_size);
60 read_attribute(block_size);
61 read_attribute(nbuckets);
62 read_attribute(tree_depth);
63 read_attribute(root_usage_percent);
64 read_attribute(priority_stats);
65 read_attribute(btree_cache_size);
66 read_attribute(btree_cache_max_chain);
67 read_attribute(cache_available_percent);
68 read_attribute(written);
69 read_attribute(btree_written);
70 read_attribute(metadata_written);
71 read_attribute(active_journal_entries);
72 read_attribute(backing_dev_name);
73 read_attribute(backing_dev_uuid);
74 
75 sysfs_time_stats_attribute(btree_gc,	sec, ms);
76 sysfs_time_stats_attribute(btree_split, sec, us);
77 sysfs_time_stats_attribute(btree_sort,	ms,  us);
78 sysfs_time_stats_attribute(btree_read,	ms,  us);
79 
80 read_attribute(btree_nodes);
81 read_attribute(btree_used_percent);
82 read_attribute(average_key_size);
83 read_attribute(dirty_data);
84 read_attribute(bset_tree_stats);
85 
86 read_attribute(state);
87 read_attribute(cache_read_races);
88 read_attribute(reclaim);
89 read_attribute(reclaimed_journal_buckets);
90 read_attribute(flush_write);
91 read_attribute(writeback_keys_done);
92 read_attribute(writeback_keys_failed);
93 read_attribute(io_errors);
94 read_attribute(congested);
95 read_attribute(cutoff_writeback);
96 read_attribute(cutoff_writeback_sync);
97 rw_attribute(congested_read_threshold_us);
98 rw_attribute(congested_write_threshold_us);
99 
100 rw_attribute(sequential_cutoff);
101 rw_attribute(data_csum);
102 rw_attribute(cache_mode);
103 rw_attribute(stop_when_cache_set_failed);
104 rw_attribute(writeback_metadata);
105 rw_attribute(writeback_running);
106 rw_attribute(writeback_percent);
107 rw_attribute(writeback_delay);
108 rw_attribute(writeback_rate);
109 
110 rw_attribute(writeback_rate_update_seconds);
111 rw_attribute(writeback_rate_i_term_inverse);
112 rw_attribute(writeback_rate_p_term_inverse);
113 rw_attribute(writeback_rate_minimum);
114 read_attribute(writeback_rate_debug);
115 
116 read_attribute(stripe_size);
117 read_attribute(partial_stripes_expensive);
118 
119 rw_attribute(synchronous);
120 rw_attribute(journal_delay_ms);
121 rw_attribute(io_disable);
122 rw_attribute(discard);
123 rw_attribute(running);
124 rw_attribute(label);
125 rw_attribute(readahead);
126 rw_attribute(errors);
127 rw_attribute(io_error_limit);
128 rw_attribute(io_error_halflife);
129 rw_attribute(verify);
130 rw_attribute(bypass_torture_test);
131 rw_attribute(key_merging_disabled);
132 rw_attribute(gc_always_rewrite);
133 rw_attribute(expensive_debug_checks);
134 rw_attribute(cache_replacement_policy);
135 rw_attribute(btree_shrinker_disabled);
136 rw_attribute(copy_gc_enabled);
137 rw_attribute(idle_max_writeback_rate);
138 rw_attribute(gc_after_writeback);
139 rw_attribute(size);
140 
141 static ssize_t bch_snprint_string_list(char *buf,
142 				       size_t size,
143 				       const char * const list[],
144 				       size_t selected)
145 {
146 	char *out = buf;
147 	size_t i;
148 
149 	for (i = 0; list[i]; i++)
150 		out += snprintf(out, buf + size - out,
151 				i == selected ? "[%s] " : "%s ", list[i]);
152 
153 	out[-1] = '\n';
154 	return out - buf;
155 }
156 
157 SHOW(__bch_cached_dev)
158 {
159 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
160 					     disk.kobj);
161 	char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
162 	int wb = dc->writeback_running;
163 
164 #define var(stat)		(dc->stat)
165 
166 	if (attr == &sysfs_cache_mode)
167 		return bch_snprint_string_list(buf, PAGE_SIZE,
168 					       bch_cache_modes,
169 					       BDEV_CACHE_MODE(&dc->sb));
170 
171 	if (attr == &sysfs_stop_when_cache_set_failed)
172 		return bch_snprint_string_list(buf, PAGE_SIZE,
173 					       bch_stop_on_failure_modes,
174 					       dc->stop_when_cache_set_failed);
175 
176 
177 	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
178 	var_printf(verify,		"%i");
179 	var_printf(bypass_torture_test,	"%i");
180 	var_printf(writeback_metadata,	"%i");
181 	var_printf(writeback_running,	"%i");
182 	var_print(writeback_delay);
183 	var_print(writeback_percent);
184 	sysfs_hprint(writeback_rate,
185 		     wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
186 	sysfs_printf(io_errors,		"%i", atomic_read(&dc->io_errors));
187 	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
188 	sysfs_printf(io_disable,	"%i", dc->io_disable);
189 	var_print(writeback_rate_update_seconds);
190 	var_print(writeback_rate_i_term_inverse);
191 	var_print(writeback_rate_p_term_inverse);
192 	var_print(writeback_rate_minimum);
193 
194 	if (attr == &sysfs_writeback_rate_debug) {
195 		char rate[20];
196 		char dirty[20];
197 		char target[20];
198 		char proportional[20];
199 		char integral[20];
200 		char change[20];
201 		s64 next_io;
202 
203 		/*
204 		 * Except for dirty and target, other values should
205 		 * be 0 if writeback is not running.
206 		 */
207 		bch_hprint(rate,
208 			   wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
209 			      : 0);
210 		bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
211 		bch_hprint(target, dc->writeback_rate_target << 9);
212 		bch_hprint(proportional,
213 			   wb ? dc->writeback_rate_proportional << 9 : 0);
214 		bch_hprint(integral,
215 			   wb ? dc->writeback_rate_integral_scaled << 9 : 0);
216 		bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
217 		next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
218 					 NSEC_PER_MSEC) : 0;
219 
220 		return sprintf(buf,
221 			       "rate:\t\t%s/sec\n"
222 			       "dirty:\t\t%s\n"
223 			       "target:\t\t%s\n"
224 			       "proportional:\t%s\n"
225 			       "integral:\t%s\n"
226 			       "change:\t\t%s/sec\n"
227 			       "next io:\t%llims\n",
228 			       rate, dirty, target, proportional,
229 			       integral, change, next_io);
230 	}
231 
232 	sysfs_hprint(dirty_data,
233 		     bcache_dev_sectors_dirty(&dc->disk) << 9);
234 
235 	sysfs_hprint(stripe_size,	 ((uint64_t)dc->disk.stripe_size) << 9);
236 	var_printf(partial_stripes_expensive,	"%u");
237 
238 	var_hprint(sequential_cutoff);
239 	var_hprint(readahead);
240 
241 	sysfs_print(running,		atomic_read(&dc->running));
242 	sysfs_print(state,		states[BDEV_STATE(&dc->sb)]);
243 
244 	if (attr == &sysfs_label) {
245 		memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
246 		buf[SB_LABEL_SIZE + 1] = '\0';
247 		strcat(buf, "\n");
248 		return strlen(buf);
249 	}
250 
251 	if (attr == &sysfs_backing_dev_name) {
252 		snprintf(buf, BDEVNAME_SIZE + 1, "%s", dc->backing_dev_name);
253 		strcat(buf, "\n");
254 		return strlen(buf);
255 	}
256 
257 	if (attr == &sysfs_backing_dev_uuid) {
258 		/* convert binary uuid into 36-byte string plus '\0' */
259 		snprintf(buf, 36+1, "%pU", dc->sb.uuid);
260 		strcat(buf, "\n");
261 		return strlen(buf);
262 	}
263 
264 #undef var
265 	return 0;
266 }
267 SHOW_LOCKED(bch_cached_dev)
268 
269 STORE(__cached_dev)
270 {
271 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
272 					     disk.kobj);
273 	ssize_t v;
274 	struct cache_set *c;
275 	struct kobj_uevent_env *env;
276 
277 	/* no user space access if system is rebooting */
278 	if (bcache_is_reboot)
279 		return -EBUSY;
280 
281 #define d_strtoul(var)		sysfs_strtoul(var, dc->var)
282 #define d_strtoul_nonzero(var)	sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
283 #define d_strtoi_h(var)		sysfs_hatoi(var, dc->var)
284 
285 	sysfs_strtoul(data_csum,	dc->disk.data_csum);
286 	d_strtoul(verify);
287 	sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test);
288 	sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata);
289 	sysfs_strtoul_bool(writeback_running, dc->writeback_running);
290 	sysfs_strtoul_clamp(writeback_delay, dc->writeback_delay, 0, UINT_MAX);
291 
292 	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent,
293 			    0, bch_cutoff_writeback);
294 
295 	if (attr == &sysfs_writeback_rate) {
296 		ssize_t ret;
297 		long int v = atomic_long_read(&dc->writeback_rate.rate);
298 
299 		ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
300 
301 		if (!ret) {
302 			atomic_long_set(&dc->writeback_rate.rate, v);
303 			ret = size;
304 		}
305 
306 		return ret;
307 	}
308 
309 	sysfs_strtoul_clamp(writeback_rate_update_seconds,
310 			    dc->writeback_rate_update_seconds,
311 			    1, WRITEBACK_RATE_UPDATE_SECS_MAX);
312 	sysfs_strtoul_clamp(writeback_rate_i_term_inverse,
313 			    dc->writeback_rate_i_term_inverse,
314 			    1, UINT_MAX);
315 	sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
316 			    dc->writeback_rate_p_term_inverse,
317 			    1, UINT_MAX);
318 	sysfs_strtoul_clamp(writeback_rate_minimum,
319 			    dc->writeback_rate_minimum,
320 			    1, UINT_MAX);
321 
322 	sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);
323 
324 	if (attr == &sysfs_io_disable) {
325 		int v = strtoul_or_return(buf);
326 
327 		dc->io_disable = v ? 1 : 0;
328 	}
329 
330 	sysfs_strtoul_clamp(sequential_cutoff,
331 			    dc->sequential_cutoff,
332 			    0, UINT_MAX);
333 	d_strtoi_h(readahead);
334 
335 	if (attr == &sysfs_clear_stats)
336 		bch_cache_accounting_clear(&dc->accounting);
337 
338 	if (attr == &sysfs_running &&
339 	    strtoul_or_return(buf)) {
340 		v = bch_cached_dev_run(dc);
341 		if (v)
342 			return v;
343 	}
344 
345 	if (attr == &sysfs_cache_mode) {
346 		v = __sysfs_match_string(bch_cache_modes, -1, buf);
347 		if (v < 0)
348 			return v;
349 
350 		if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
351 			SET_BDEV_CACHE_MODE(&dc->sb, v);
352 			bch_write_bdev_super(dc, NULL);
353 		}
354 	}
355 
356 	if (attr == &sysfs_stop_when_cache_set_failed) {
357 		v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
358 		if (v < 0)
359 			return v;
360 
361 		dc->stop_when_cache_set_failed = v;
362 	}
363 
364 	if (attr == &sysfs_label) {
365 		if (size > SB_LABEL_SIZE)
366 			return -EINVAL;
367 		memcpy(dc->sb.label, buf, size);
368 		if (size < SB_LABEL_SIZE)
369 			dc->sb.label[size] = '\0';
370 		if (size && dc->sb.label[size - 1] == '\n')
371 			dc->sb.label[size - 1] = '\0';
372 		bch_write_bdev_super(dc, NULL);
373 		if (dc->disk.c) {
374 			memcpy(dc->disk.c->uuids[dc->disk.id].label,
375 			       buf, SB_LABEL_SIZE);
376 			bch_uuid_write(dc->disk.c);
377 		}
378 		env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
379 		if (!env)
380 			return -ENOMEM;
381 		add_uevent_var(env, "DRIVER=bcache");
382 		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
383 		add_uevent_var(env, "CACHED_LABEL=%s", buf);
384 		kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj,
385 				   KOBJ_CHANGE,
386 				   env->envp);
387 		kfree(env);
388 	}
389 
390 	if (attr == &sysfs_attach) {
391 		uint8_t		set_uuid[16];
392 
393 		if (bch_parse_uuid(buf, set_uuid) < 16)
394 			return -EINVAL;
395 
396 		v = -ENOENT;
397 		list_for_each_entry(c, &bch_cache_sets, list) {
398 			v = bch_cached_dev_attach(dc, c, set_uuid);
399 			if (!v)
400 				return size;
401 		}
402 		if (v == -ENOENT)
403 			pr_err("Can't attach %s: cache set not found", buf);
404 		return v;
405 	}
406 
407 	if (attr == &sysfs_detach && dc->disk.c)
408 		bch_cached_dev_detach(dc);
409 
410 	if (attr == &sysfs_stop)
411 		bcache_device_stop(&dc->disk);
412 
413 	return size;
414 }
415 
416 STORE(bch_cached_dev)
417 {
418 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
419 					     disk.kobj);
420 
421 	/* no user space access if system is rebooting */
422 	if (bcache_is_reboot)
423 		return -EBUSY;
424 
425 	mutex_lock(&bch_register_lock);
426 	size = __cached_dev_store(kobj, attr, buf, size);
427 
428 	if (attr == &sysfs_writeback_running) {
429 		/* dc->writeback_running changed in __cached_dev_store() */
430 		if (IS_ERR_OR_NULL(dc->writeback_thread)) {
431 			/*
432 			 * reject setting it to 1 via sysfs if writeback
433 			 * kthread is not created yet.
434 			 */
435 			if (dc->writeback_running) {
436 				dc->writeback_running = false;
437 				pr_err("%s: failed to run non-existent writeback thread",
438 						dc->disk.disk->disk_name);
439 			}
440 		} else
441 			/*
442 			 * writeback kthread will check if dc->writeback_running
443 			 * is true or false.
444 			 */
445 			bch_writeback_queue(dc);
446 	}
447 
448 	/*
449 	 * Only set BCACHE_DEV_WB_RUNNING when cached device attached to
450 	 * a cache set, otherwise it doesn't make sense.
451 	 */
452 	if (attr == &sysfs_writeback_percent)
453 		if ((dc->disk.c != NULL) &&
454 		    (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)))
455 			schedule_delayed_work(&dc->writeback_rate_update,
456 				      dc->writeback_rate_update_seconds * HZ);
457 
458 	mutex_unlock(&bch_register_lock);
459 	return size;
460 }
461 
462 static struct attribute *bch_cached_dev_files[] = {
463 	&sysfs_attach,
464 	&sysfs_detach,
465 	&sysfs_stop,
466 #if 0
467 	&sysfs_data_csum,
468 #endif
469 	&sysfs_cache_mode,
470 	&sysfs_stop_when_cache_set_failed,
471 	&sysfs_writeback_metadata,
472 	&sysfs_writeback_running,
473 	&sysfs_writeback_delay,
474 	&sysfs_writeback_percent,
475 	&sysfs_writeback_rate,
476 	&sysfs_writeback_rate_update_seconds,
477 	&sysfs_writeback_rate_i_term_inverse,
478 	&sysfs_writeback_rate_p_term_inverse,
479 	&sysfs_writeback_rate_minimum,
480 	&sysfs_writeback_rate_debug,
481 	&sysfs_io_errors,
482 	&sysfs_io_error_limit,
483 	&sysfs_io_disable,
484 	&sysfs_dirty_data,
485 	&sysfs_stripe_size,
486 	&sysfs_partial_stripes_expensive,
487 	&sysfs_sequential_cutoff,
488 	&sysfs_clear_stats,
489 	&sysfs_running,
490 	&sysfs_state,
491 	&sysfs_label,
492 	&sysfs_readahead,
493 #ifdef CONFIG_BCACHE_DEBUG
494 	&sysfs_verify,
495 	&sysfs_bypass_torture_test,
496 #endif
497 	&sysfs_backing_dev_name,
498 	&sysfs_backing_dev_uuid,
499 	NULL
500 };
501 KTYPE(bch_cached_dev);
502 
503 SHOW(bch_flash_dev)
504 {
505 	struct bcache_device *d = container_of(kobj, struct bcache_device,
506 					       kobj);
507 	struct uuid_entry *u = &d->c->uuids[d->id];
508 
509 	sysfs_printf(data_csum,	"%i", d->data_csum);
510 	sysfs_hprint(size,	u->sectors << 9);
511 
512 	if (attr == &sysfs_label) {
513 		memcpy(buf, u->label, SB_LABEL_SIZE);
514 		buf[SB_LABEL_SIZE + 1] = '\0';
515 		strcat(buf, "\n");
516 		return strlen(buf);
517 	}
518 
519 	return 0;
520 }
521 
522 STORE(__bch_flash_dev)
523 {
524 	struct bcache_device *d = container_of(kobj, struct bcache_device,
525 					       kobj);
526 	struct uuid_entry *u = &d->c->uuids[d->id];
527 
528 	/* no user space access if system is rebooting */
529 	if (bcache_is_reboot)
530 		return -EBUSY;
531 
532 	sysfs_strtoul(data_csum,	d->data_csum);
533 
534 	if (attr == &sysfs_size) {
535 		uint64_t v;
536 
537 		strtoi_h_or_return(buf, v);
538 
539 		u->sectors = v >> 9;
540 		bch_uuid_write(d->c);
541 		set_capacity(d->disk, u->sectors);
542 	}
543 
544 	if (attr == &sysfs_label) {
545 		memcpy(u->label, buf, SB_LABEL_SIZE);
546 		bch_uuid_write(d->c);
547 	}
548 
549 	if (attr == &sysfs_unregister) {
550 		set_bit(BCACHE_DEV_DETACHING, &d->flags);
551 		bcache_device_stop(d);
552 	}
553 
554 	return size;
555 }
556 STORE_LOCKED(bch_flash_dev)
557 
558 static struct attribute *bch_flash_dev_files[] = {
559 	&sysfs_unregister,
560 #if 0
561 	&sysfs_data_csum,
562 #endif
563 	&sysfs_label,
564 	&sysfs_size,
565 	NULL
566 };
567 KTYPE(bch_flash_dev);
568 
569 struct bset_stats_op {
570 	struct btree_op op;
571 	size_t nodes;
572 	struct bset_stats stats;
573 };
574 
575 static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b)
576 {
577 	struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op);
578 
579 	op->nodes++;
580 	bch_btree_keys_stats(&b->keys, &op->stats);
581 
582 	return MAP_CONTINUE;
583 }
584 
585 static int bch_bset_print_stats(struct cache_set *c, char *buf)
586 {
587 	struct bset_stats_op op;
588 	int ret;
589 
590 	memset(&op, 0, sizeof(op));
591 	bch_btree_op_init(&op.op, -1);
592 
593 	ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats);
594 	if (ret < 0)
595 		return ret;
596 
597 	return snprintf(buf, PAGE_SIZE,
598 			"btree nodes:		%zu\n"
599 			"written sets:		%zu\n"
600 			"unwritten sets:		%zu\n"
601 			"written key bytes:	%zu\n"
602 			"unwritten key bytes:	%zu\n"
603 			"floats:			%zu\n"
604 			"failed:			%zu\n",
605 			op.nodes,
606 			op.stats.sets_written, op.stats.sets_unwritten,
607 			op.stats.bytes_written, op.stats.bytes_unwritten,
608 			op.stats.floats, op.stats.failed);
609 }
610 
611 static unsigned int bch_root_usage(struct cache_set *c)
612 {
613 	unsigned int bytes = 0;
614 	struct bkey *k;
615 	struct btree *b;
616 	struct btree_iter iter;
617 
618 	goto lock_root;
619 
620 	do {
621 		rw_unlock(false, b);
622 lock_root:
623 		b = c->root;
624 		rw_lock(false, b, b->level);
625 	} while (b != c->root);
626 
627 	for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
628 		bytes += bkey_bytes(k);
629 
630 	rw_unlock(false, b);
631 
632 	return (bytes * 100) / btree_bytes(c);
633 }
634 
635 static size_t bch_cache_size(struct cache_set *c)
636 {
637 	size_t ret = 0;
638 	struct btree *b;
639 
640 	mutex_lock(&c->bucket_lock);
641 	list_for_each_entry(b, &c->btree_cache, list)
642 		ret += 1 << (b->keys.page_order + PAGE_SHIFT);
643 
644 	mutex_unlock(&c->bucket_lock);
645 	return ret;
646 }
647 
648 static unsigned int bch_cache_max_chain(struct cache_set *c)
649 {
650 	unsigned int ret = 0;
651 	struct hlist_head *h;
652 
653 	mutex_lock(&c->bucket_lock);
654 
655 	for (h = c->bucket_hash;
656 	     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
657 	     h++) {
658 		unsigned int i = 0;
659 		struct hlist_node *p;
660 
661 		hlist_for_each(p, h)
662 			i++;
663 
664 		ret = max(ret, i);
665 	}
666 
667 	mutex_unlock(&c->bucket_lock);
668 	return ret;
669 }
670 
671 static unsigned int bch_btree_used(struct cache_set *c)
672 {
673 	return div64_u64(c->gc_stats.key_bytes * 100,
674 			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
675 }
676 
677 static unsigned int bch_average_key_size(struct cache_set *c)
678 {
679 	return c->gc_stats.nkeys
680 		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
681 		: 0;
682 }
683 
684 SHOW(__bch_cache_set)
685 {
686 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
687 
688 	sysfs_print(synchronous,		CACHE_SYNC(&c->sb));
689 	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
690 	sysfs_hprint(bucket_size,		bucket_bytes(c));
691 	sysfs_hprint(block_size,		block_bytes(c));
692 	sysfs_print(tree_depth,			c->root->level);
693 	sysfs_print(root_usage_percent,		bch_root_usage(c));
694 
695 	sysfs_hprint(btree_cache_size,		bch_cache_size(c));
696 	sysfs_print(btree_cache_max_chain,	bch_cache_max_chain(c));
697 	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
698 
699 	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
700 	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
701 	sysfs_print_time_stats(&c->sort.time,		btree_sort, ms, us);
702 	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
703 
704 	sysfs_print(btree_used_percent,	bch_btree_used(c));
705 	sysfs_print(btree_nodes,	c->gc_stats.nodes);
706 	sysfs_hprint(average_key_size,	bch_average_key_size(c));
707 
708 	sysfs_print(cache_read_races,
709 		    atomic_long_read(&c->cache_read_races));
710 
711 	sysfs_print(reclaim,
712 		    atomic_long_read(&c->reclaim));
713 
714 	sysfs_print(reclaimed_journal_buckets,
715 		    atomic_long_read(&c->reclaimed_journal_buckets));
716 
717 	sysfs_print(flush_write,
718 		    atomic_long_read(&c->flush_write));
719 
720 	sysfs_print(writeback_keys_done,
721 		    atomic_long_read(&c->writeback_keys_done));
722 	sysfs_print(writeback_keys_failed,
723 		    atomic_long_read(&c->writeback_keys_failed));
724 
725 	if (attr == &sysfs_errors)
726 		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
727 					       c->on_error);
728 
729 	/* See count_io_errors for why 88 */
730 	sysfs_print(io_error_halflife,	c->error_decay * 88);
731 	sysfs_print(io_error_limit,	c->error_limit);
732 
733 	sysfs_hprint(congested,
734 		     ((uint64_t) bch_get_congested(c)) << 9);
735 	sysfs_print(congested_read_threshold_us,
736 		    c->congested_read_threshold_us);
737 	sysfs_print(congested_write_threshold_us,
738 		    c->congested_write_threshold_us);
739 
740 	sysfs_print(cutoff_writeback, bch_cutoff_writeback);
741 	sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync);
742 
743 	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
744 	sysfs_printf(verify,			"%i", c->verify);
745 	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
746 	sysfs_printf(expensive_debug_checks,
747 		     "%i", c->expensive_debug_checks);
748 	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
749 	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
750 	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
751 	sysfs_printf(idle_max_writeback_rate,	"%i",
752 		     c->idle_max_writeback_rate_enabled);
753 	sysfs_printf(gc_after_writeback,	"%i", c->gc_after_writeback);
754 	sysfs_printf(io_disable,		"%i",
755 		     test_bit(CACHE_SET_IO_DISABLE, &c->flags));
756 
757 	if (attr == &sysfs_bset_tree_stats)
758 		return bch_bset_print_stats(c, buf);
759 
760 	return 0;
761 }
762 SHOW_LOCKED(bch_cache_set)
763 
764 STORE(__bch_cache_set)
765 {
766 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
767 	ssize_t v;
768 
769 	/* no user space access if system is rebooting */
770 	if (bcache_is_reboot)
771 		return -EBUSY;
772 
773 	if (attr == &sysfs_unregister)
774 		bch_cache_set_unregister(c);
775 
776 	if (attr == &sysfs_stop)
777 		bch_cache_set_stop(c);
778 
779 	if (attr == &sysfs_synchronous) {
780 		bool sync = strtoul_or_return(buf);
781 
782 		if (sync != CACHE_SYNC(&c->sb)) {
783 			SET_CACHE_SYNC(&c->sb, sync);
784 			bcache_write_super(c);
785 		}
786 	}
787 
788 	if (attr == &sysfs_flash_vol_create) {
789 		int r;
790 		uint64_t v;
791 
792 		strtoi_h_or_return(buf, v);
793 
794 		r = bch_flash_dev_create(c, v);
795 		if (r)
796 			return r;
797 	}
798 
799 	if (attr == &sysfs_clear_stats) {
800 		atomic_long_set(&c->writeback_keys_done,	0);
801 		atomic_long_set(&c->writeback_keys_failed,	0);
802 
803 		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
804 		bch_cache_accounting_clear(&c->accounting);
805 	}
806 
807 	if (attr == &sysfs_trigger_gc)
808 		force_wake_up_gc(c);
809 
810 	if (attr == &sysfs_prune_cache) {
811 		struct shrink_control sc;
812 
813 		sc.gfp_mask = GFP_KERNEL;
814 		sc.nr_to_scan = strtoul_or_return(buf);
815 		c->shrink.scan_objects(&c->shrink, &sc);
816 	}
817 
818 	sysfs_strtoul_clamp(congested_read_threshold_us,
819 			    c->congested_read_threshold_us,
820 			    0, UINT_MAX);
821 	sysfs_strtoul_clamp(congested_write_threshold_us,
822 			    c->congested_write_threshold_us,
823 			    0, UINT_MAX);
824 
825 	if (attr == &sysfs_errors) {
826 		v = __sysfs_match_string(error_actions, -1, buf);
827 		if (v < 0)
828 			return v;
829 
830 		c->on_error = v;
831 	}
832 
833 	sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
834 
835 	/* See count_io_errors() for why 88 */
836 	if (attr == &sysfs_io_error_halflife) {
837 		unsigned long v = 0;
838 		ssize_t ret;
839 
840 		ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX);
841 		if (!ret) {
842 			c->error_decay = v / 88;
843 			return size;
844 		}
845 		return ret;
846 	}
847 
848 	if (attr == &sysfs_io_disable) {
849 		v = strtoul_or_return(buf);
850 		if (v) {
851 			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
852 					     &c->flags))
853 				pr_warn("CACHE_SET_IO_DISABLE already set");
854 		} else {
855 			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
856 						&c->flags))
857 				pr_warn("CACHE_SET_IO_DISABLE already cleared");
858 		}
859 	}
860 
861 	sysfs_strtoul_clamp(journal_delay_ms,
862 			    c->journal_delay_ms,
863 			    0, USHRT_MAX);
864 	sysfs_strtoul_bool(verify,		c->verify);
865 	sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
866 	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
867 	sysfs_strtoul_bool(gc_always_rewrite,	c->gc_always_rewrite);
868 	sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
869 	sysfs_strtoul_bool(copy_gc_enabled,	c->copy_gc_enabled);
870 	sysfs_strtoul_bool(idle_max_writeback_rate,
871 			   c->idle_max_writeback_rate_enabled);
872 
873 	/*
874 	 * write gc_after_writeback here may overwrite an already set
875 	 * BCH_DO_AUTO_GC, it doesn't matter because this flag will be
876 	 * set in next chance.
877 	 */
878 	sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1);
879 
880 	return size;
881 }
882 STORE_LOCKED(bch_cache_set)
883 
884 SHOW(bch_cache_set_internal)
885 {
886 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
887 
888 	return bch_cache_set_show(&c->kobj, attr, buf);
889 }
890 
891 STORE(bch_cache_set_internal)
892 {
893 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
894 
895 	/* no user space access if system is rebooting */
896 	if (bcache_is_reboot)
897 		return -EBUSY;
898 
899 	return bch_cache_set_store(&c->kobj, attr, buf, size);
900 }
901 
902 static void bch_cache_set_internal_release(struct kobject *k)
903 {
904 }
905 
906 static struct attribute *bch_cache_set_files[] = {
907 	&sysfs_unregister,
908 	&sysfs_stop,
909 	&sysfs_synchronous,
910 	&sysfs_journal_delay_ms,
911 	&sysfs_flash_vol_create,
912 
913 	&sysfs_bucket_size,
914 	&sysfs_block_size,
915 	&sysfs_tree_depth,
916 	&sysfs_root_usage_percent,
917 	&sysfs_btree_cache_size,
918 	&sysfs_cache_available_percent,
919 
920 	&sysfs_average_key_size,
921 
922 	&sysfs_errors,
923 	&sysfs_io_error_limit,
924 	&sysfs_io_error_halflife,
925 	&sysfs_congested,
926 	&sysfs_congested_read_threshold_us,
927 	&sysfs_congested_write_threshold_us,
928 	&sysfs_clear_stats,
929 	NULL
930 };
931 KTYPE(bch_cache_set);
932 
933 static struct attribute *bch_cache_set_internal_files[] = {
934 	&sysfs_active_journal_entries,
935 
936 	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
937 	sysfs_time_stats_attribute_list(btree_split, sec, us)
938 	sysfs_time_stats_attribute_list(btree_sort, ms, us)
939 	sysfs_time_stats_attribute_list(btree_read, ms, us)
940 
941 	&sysfs_btree_nodes,
942 	&sysfs_btree_used_percent,
943 	&sysfs_btree_cache_max_chain,
944 
945 	&sysfs_bset_tree_stats,
946 	&sysfs_cache_read_races,
947 	&sysfs_reclaim,
948 	&sysfs_reclaimed_journal_buckets,
949 	&sysfs_flush_write,
950 	&sysfs_writeback_keys_done,
951 	&sysfs_writeback_keys_failed,
952 
953 	&sysfs_trigger_gc,
954 	&sysfs_prune_cache,
955 #ifdef CONFIG_BCACHE_DEBUG
956 	&sysfs_verify,
957 	&sysfs_key_merging_disabled,
958 	&sysfs_expensive_debug_checks,
959 #endif
960 	&sysfs_gc_always_rewrite,
961 	&sysfs_btree_shrinker_disabled,
962 	&sysfs_copy_gc_enabled,
963 	&sysfs_idle_max_writeback_rate,
964 	&sysfs_gc_after_writeback,
965 	&sysfs_io_disable,
966 	&sysfs_cutoff_writeback,
967 	&sysfs_cutoff_writeback_sync,
968 	NULL
969 };
970 KTYPE(bch_cache_set_internal);
971 
972 static int __bch_cache_cmp(const void *l, const void *r)
973 {
974 	cond_resched();
975 	return *((uint16_t *)r) - *((uint16_t *)l);
976 }
977 
978 SHOW(__bch_cache)
979 {
980 	struct cache *ca = container_of(kobj, struct cache, kobj);
981 
982 	sysfs_hprint(bucket_size,	bucket_bytes(ca));
983 	sysfs_hprint(block_size,	block_bytes(ca));
984 	sysfs_print(nbuckets,		ca->sb.nbuckets);
985 	sysfs_print(discard,		ca->discard);
986 	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
987 	sysfs_hprint(btree_written,
988 		     atomic_long_read(&ca->btree_sectors_written) << 9);
989 	sysfs_hprint(metadata_written,
990 		     (atomic_long_read(&ca->meta_sectors_written) +
991 		      atomic_long_read(&ca->btree_sectors_written)) << 9);
992 
993 	sysfs_print(io_errors,
994 		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
995 
996 	if (attr == &sysfs_cache_replacement_policy)
997 		return bch_snprint_string_list(buf, PAGE_SIZE,
998 					       cache_replacement_policies,
999 					       CACHE_REPLACEMENT(&ca->sb));
1000 
1001 	if (attr == &sysfs_priority_stats) {
1002 		struct bucket *b;
1003 		size_t n = ca->sb.nbuckets, i;
1004 		size_t unused = 0, available = 0, dirty = 0, meta = 0;
1005 		uint64_t sum = 0;
1006 		/* Compute 31 quantiles */
1007 		uint16_t q[31], *p, *cached;
1008 		ssize_t ret;
1009 
1010 		cached = p = vmalloc(array_size(sizeof(uint16_t),
1011 						ca->sb.nbuckets));
1012 		if (!p)
1013 			return -ENOMEM;
1014 
1015 		mutex_lock(&ca->set->bucket_lock);
1016 		for_each_bucket(b, ca) {
1017 			if (!GC_SECTORS_USED(b))
1018 				unused++;
1019 			if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
1020 				available++;
1021 			if (GC_MARK(b) == GC_MARK_DIRTY)
1022 				dirty++;
1023 			if (GC_MARK(b) == GC_MARK_METADATA)
1024 				meta++;
1025 		}
1026 
1027 		for (i = ca->sb.first_bucket; i < n; i++)
1028 			p[i] = ca->buckets[i].prio;
1029 		mutex_unlock(&ca->set->bucket_lock);
1030 
1031 		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
1032 
1033 		while (n &&
1034 		       !cached[n - 1])
1035 			--n;
1036 
1037 		while (cached < p + n &&
1038 		       *cached == BTREE_PRIO)
1039 			cached++, n--;
1040 
1041 		for (i = 0; i < n; i++)
1042 			sum += INITIAL_PRIO - cached[i];
1043 
1044 		if (n)
1045 			do_div(sum, n);
1046 
1047 		for (i = 0; i < ARRAY_SIZE(q); i++)
1048 			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
1049 				(ARRAY_SIZE(q) + 1)];
1050 
1051 		vfree(p);
1052 
1053 		ret = scnprintf(buf, PAGE_SIZE,
1054 				"Unused:		%zu%%\n"
1055 				"Clean:		%zu%%\n"
1056 				"Dirty:		%zu%%\n"
1057 				"Metadata:	%zu%%\n"
1058 				"Average:	%llu\n"
1059 				"Sectors per Q:	%zu\n"
1060 				"Quantiles:	[",
1061 				unused * 100 / (size_t) ca->sb.nbuckets,
1062 				available * 100 / (size_t) ca->sb.nbuckets,
1063 				dirty * 100 / (size_t) ca->sb.nbuckets,
1064 				meta * 100 / (size_t) ca->sb.nbuckets, sum,
1065 				n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
1066 
1067 		for (i = 0; i < ARRAY_SIZE(q); i++)
1068 			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
1069 					 "%u ", q[i]);
1070 		ret--;
1071 
1072 		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
1073 
1074 		return ret;
1075 	}
1076 
1077 	return 0;
1078 }
1079 SHOW_LOCKED(bch_cache)
1080 
1081 STORE(__bch_cache)
1082 {
1083 	struct cache *ca = container_of(kobj, struct cache, kobj);
1084 	ssize_t v;
1085 
1086 	/* no user space access if system is rebooting */
1087 	if (bcache_is_reboot)
1088 		return -EBUSY;
1089 
1090 	if (attr == &sysfs_discard) {
1091 		bool v = strtoul_or_return(buf);
1092 
1093 		if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1094 			ca->discard = v;
1095 
1096 		if (v != CACHE_DISCARD(&ca->sb)) {
1097 			SET_CACHE_DISCARD(&ca->sb, v);
1098 			bcache_write_super(ca->set);
1099 		}
1100 	}
1101 
1102 	if (attr == &sysfs_cache_replacement_policy) {
1103 		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
1104 		if (v < 0)
1105 			return v;
1106 
1107 		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
1108 			mutex_lock(&ca->set->bucket_lock);
1109 			SET_CACHE_REPLACEMENT(&ca->sb, v);
1110 			mutex_unlock(&ca->set->bucket_lock);
1111 
1112 			bcache_write_super(ca->set);
1113 		}
1114 	}
1115 
1116 	if (attr == &sysfs_clear_stats) {
1117 		atomic_long_set(&ca->sectors_written, 0);
1118 		atomic_long_set(&ca->btree_sectors_written, 0);
1119 		atomic_long_set(&ca->meta_sectors_written, 0);
1120 		atomic_set(&ca->io_count, 0);
1121 		atomic_set(&ca->io_errors, 0);
1122 	}
1123 
1124 	return size;
1125 }
1126 STORE_LOCKED(bch_cache)
1127 
1128 static struct attribute *bch_cache_files[] = {
1129 	&sysfs_bucket_size,
1130 	&sysfs_block_size,
1131 	&sysfs_nbuckets,
1132 	&sysfs_priority_stats,
1133 	&sysfs_discard,
1134 	&sysfs_written,
1135 	&sysfs_btree_written,
1136 	&sysfs_metadata_written,
1137 	&sysfs_io_errors,
1138 	&sysfs_clear_stats,
1139 	&sysfs_cache_replacement_policy,
1140 	NULL
1141 };
1142 KTYPE(bch_cache);
1143