xref: /linux/drivers/md/bcache/sysfs.c (revision cc25df3e2e22a956d3a0d427369367b4a901d203)
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 
20 extern bool bcache_is_reboot;
21 
22 /* Default is 0 ("writethrough") */
23 static const char * const bch_cache_modes[] = {
24 	"writethrough",
25 	"writeback",
26 	"writearound",
27 	"none",
28 	NULL
29 };
30 
31 static const char * const bch_reada_cache_policies[] = {
32 	"all",
33 	"meta-only",
34 	NULL
35 };
36 
37 /* Default is 0 ("auto") */
38 static const char * const bch_stop_on_failure_modes[] = {
39 	"auto",
40 	"always",
41 	NULL
42 };
43 
44 static const char * const cache_replacement_policies[] = {
45 	"lru",
46 	"fifo",
47 	"random",
48 	NULL
49 };
50 
51 static const char * const error_actions[] = {
52 	"unregister",
53 	"panic",
54 	NULL
55 };
56 
57 write_attribute(attach);
58 write_attribute(detach);
59 write_attribute(unregister);
60 write_attribute(stop);
61 write_attribute(clear_stats);
62 write_attribute(trigger_gc);
63 write_attribute(prune_cache);
64 write_attribute(flash_vol_create);
65 
66 read_attribute(bucket_size);
67 read_attribute(block_size);
68 read_attribute(nbuckets);
69 read_attribute(tree_depth);
70 read_attribute(root_usage_percent);
71 read_attribute(priority_stats);
72 read_attribute(btree_cache_size);
73 read_attribute(btree_cache_max_chain);
74 read_attribute(cache_available_percent);
75 read_attribute(written);
76 read_attribute(btree_written);
77 read_attribute(metadata_written);
78 read_attribute(active_journal_entries);
79 read_attribute(backing_dev_name);
80 read_attribute(backing_dev_uuid);
81 
82 sysfs_time_stats_attribute(btree_gc,	sec, ms);
83 sysfs_time_stats_attribute(btree_split, sec, us);
84 sysfs_time_stats_attribute(btree_sort,	ms,  us);
85 sysfs_time_stats_attribute(btree_read,	ms,  us);
86 
87 read_attribute(btree_nodes);
88 read_attribute(btree_used_percent);
89 read_attribute(average_key_size);
90 read_attribute(dirty_data);
91 read_attribute(bset_tree_stats);
92 read_attribute(feature_compat);
93 read_attribute(feature_ro_compat);
94 read_attribute(feature_incompat);
95 
96 read_attribute(state);
97 read_attribute(cache_read_races);
98 read_attribute(reclaim);
99 read_attribute(reclaimed_journal_buckets);
100 read_attribute(flush_write);
101 read_attribute(writeback_keys_done);
102 read_attribute(writeback_keys_failed);
103 read_attribute(io_errors);
104 read_attribute(congested);
105 read_attribute(cutoff_writeback);
106 read_attribute(cutoff_writeback_sync);
107 rw_attribute(congested_read_threshold_us);
108 rw_attribute(congested_write_threshold_us);
109 
110 rw_attribute(sequential_cutoff);
111 rw_attribute(data_csum);
112 rw_attribute(cache_mode);
113 rw_attribute(readahead_cache_policy);
114 rw_attribute(stop_when_cache_set_failed);
115 rw_attribute(writeback_metadata);
116 rw_attribute(writeback_running);
117 rw_attribute(writeback_percent);
118 rw_attribute(writeback_delay);
119 rw_attribute(writeback_rate);
120 rw_attribute(writeback_consider_fragment);
121 
122 rw_attribute(writeback_rate_update_seconds);
123 rw_attribute(writeback_rate_i_term_inverse);
124 rw_attribute(writeback_rate_p_term_inverse);
125 rw_attribute(writeback_rate_fp_term_low);
126 rw_attribute(writeback_rate_fp_term_mid);
127 rw_attribute(writeback_rate_fp_term_high);
128 rw_attribute(writeback_rate_minimum);
129 read_attribute(writeback_rate_debug);
130 
131 read_attribute(stripe_size);
132 read_attribute(partial_stripes_expensive);
133 
134 rw_attribute(synchronous);
135 rw_attribute(journal_delay_ms);
136 rw_attribute(io_disable);
137 rw_attribute(running);
138 rw_attribute(label);
139 rw_attribute(errors);
140 rw_attribute(io_error_limit);
141 rw_attribute(io_error_halflife);
142 rw_attribute(verify);
143 rw_attribute(bypass_torture_test);
144 rw_attribute(key_merging_disabled);
145 rw_attribute(gc_always_rewrite);
146 rw_attribute(expensive_debug_checks);
147 rw_attribute(cache_replacement_policy);
148 rw_attribute(btree_shrinker_disabled);
149 rw_attribute(copy_gc_enabled);
150 rw_attribute(idle_max_writeback_rate);
151 rw_attribute(gc_after_writeback);
152 rw_attribute(size);
153 
154 static ssize_t bch_snprint_string_list(char *buf,
155 				       size_t size,
156 				       const char * const list[],
157 				       size_t selected)
158 {
159 	char *out = buf;
160 	size_t i;
161 
162 	for (i = 0; list[i]; i++)
163 		out += scnprintf(out, buf + size - out,
164 				i == selected ? "[%s] " : "%s ", list[i]);
165 
166 	out[-1] = '\n';
167 	return out - buf;
168 }
169 
170 SHOW(__bch_cached_dev)
171 {
172 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
173 					     disk.kobj);
174 	char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
175 	int wb = dc->writeback_running;
176 
177 #define var(stat)		(dc->stat)
178 
179 	if (attr == &sysfs_cache_mode)
180 		return bch_snprint_string_list(buf, PAGE_SIZE,
181 					       bch_cache_modes,
182 					       BDEV_CACHE_MODE(&dc->sb));
183 
184 	if (attr == &sysfs_readahead_cache_policy)
185 		return bch_snprint_string_list(buf, PAGE_SIZE,
186 					      bch_reada_cache_policies,
187 					      dc->cache_readahead_policy);
188 
189 	if (attr == &sysfs_stop_when_cache_set_failed)
190 		return bch_snprint_string_list(buf, PAGE_SIZE,
191 					       bch_stop_on_failure_modes,
192 					       dc->stop_when_cache_set_failed);
193 
194 
195 	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
196 	var_printf(verify,		"%i");
197 	var_printf(bypass_torture_test,	"%i");
198 	var_printf(writeback_metadata,	"%i");
199 	var_printf(writeback_running,	"%i");
200 	var_printf(writeback_consider_fragment,	"%i");
201 	var_print(writeback_delay);
202 	var_print(writeback_percent);
203 	sysfs_hprint(writeback_rate,
204 		     wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
205 	sysfs_printf(io_errors,		"%i", atomic_read(&dc->io_errors));
206 	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
207 	sysfs_printf(io_disable,	"%i", dc->io_disable);
208 	var_print(writeback_rate_update_seconds);
209 	var_print(writeback_rate_i_term_inverse);
210 	var_print(writeback_rate_p_term_inverse);
211 	var_print(writeback_rate_fp_term_low);
212 	var_print(writeback_rate_fp_term_mid);
213 	var_print(writeback_rate_fp_term_high);
214 	var_print(writeback_rate_minimum);
215 
216 	if (attr == &sysfs_writeback_rate_debug) {
217 		char rate[20];
218 		char dirty[20];
219 		char target[20];
220 		char proportional[20];
221 		char integral[20];
222 		char change[20];
223 		s64 next_io;
224 
225 		/*
226 		 * Except for dirty and target, other values should
227 		 * be 0 if writeback is not running.
228 		 */
229 		bch_hprint(rate,
230 			   wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
231 			      : 0);
232 		bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
233 		bch_hprint(target, dc->writeback_rate_target << 9);
234 		bch_hprint(proportional,
235 			   wb ? dc->writeback_rate_proportional << 9 : 0);
236 		bch_hprint(integral,
237 			   wb ? dc->writeback_rate_integral_scaled << 9 : 0);
238 		bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
239 		next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
240 					 NSEC_PER_MSEC) : 0;
241 
242 		return sprintf(buf,
243 			       "rate:\t\t%s/sec\n"
244 			       "dirty:\t\t%s\n"
245 			       "target:\t\t%s\n"
246 			       "proportional:\t%s\n"
247 			       "integral:\t%s\n"
248 			       "change:\t\t%s/sec\n"
249 			       "next io:\t%llims\n",
250 			       rate, dirty, target, proportional,
251 			       integral, change, next_io);
252 	}
253 
254 	sysfs_hprint(dirty_data,
255 		     bcache_dev_sectors_dirty(&dc->disk) << 9);
256 
257 	sysfs_hprint(stripe_size,	 ((uint64_t)dc->disk.stripe_size) << 9);
258 	var_printf(partial_stripes_expensive,	"%u");
259 
260 	var_hprint(sequential_cutoff);
261 
262 	sysfs_print(running,		atomic_read(&dc->running));
263 	sysfs_print(state,		states[BDEV_STATE(&dc->sb)]);
264 
265 	if (attr == &sysfs_label) {
266 		memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
267 		buf[SB_LABEL_SIZE + 1] = '\0';
268 		strcat(buf, "\n");
269 		return strlen(buf);
270 	}
271 
272 	if (attr == &sysfs_backing_dev_name) {
273 		snprintf(buf, BDEVNAME_SIZE + 1, "%pg", dc->bdev);
274 		strcat(buf, "\n");
275 		return strlen(buf);
276 	}
277 
278 	if (attr == &sysfs_backing_dev_uuid) {
279 		/* convert binary uuid into 36-byte string plus '\0' */
280 		snprintf(buf, 36+1, "%pU", dc->sb.uuid);
281 		strcat(buf, "\n");
282 		return strlen(buf);
283 	}
284 
285 #undef var
286 	return 0;
287 }
288 SHOW_LOCKED(bch_cached_dev)
289 
290 STORE(__cached_dev)
291 {
292 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
293 					     disk.kobj);
294 	ssize_t v;
295 	struct cache_set *c;
296 	struct kobj_uevent_env *env;
297 
298 	/* no user space access if system is rebooting */
299 	if (bcache_is_reboot)
300 		return -EBUSY;
301 
302 #define d_strtoul(var)		sysfs_strtoul(var, dc->var)
303 #define d_strtoul_nonzero(var)	sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
304 #define d_strtoi_h(var)		sysfs_hatoi(var, dc->var)
305 
306 	sysfs_strtoul(data_csum,	dc->disk.data_csum);
307 	d_strtoul(verify);
308 	sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test);
309 	sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata);
310 	sysfs_strtoul_bool(writeback_running, dc->writeback_running);
311 	sysfs_strtoul_bool(writeback_consider_fragment, dc->writeback_consider_fragment);
312 	sysfs_strtoul_clamp(writeback_delay, dc->writeback_delay, 0, UINT_MAX);
313 
314 	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent,
315 			    0, bch_cutoff_writeback);
316 
317 	if (attr == &sysfs_writeback_rate) {
318 		ssize_t ret;
319 		long int v = atomic_long_read(&dc->writeback_rate.rate);
320 
321 		ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
322 
323 		if (!ret) {
324 			atomic_long_set(&dc->writeback_rate.rate, v);
325 			ret = size;
326 		}
327 
328 		return ret;
329 	}
330 
331 	sysfs_strtoul_clamp(writeback_rate_update_seconds,
332 			    dc->writeback_rate_update_seconds,
333 			    1, WRITEBACK_RATE_UPDATE_SECS_MAX);
334 	sysfs_strtoul_clamp(writeback_rate_i_term_inverse,
335 			    dc->writeback_rate_i_term_inverse,
336 			    1, UINT_MAX);
337 	sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
338 			    dc->writeback_rate_p_term_inverse,
339 			    1, UINT_MAX);
340 	sysfs_strtoul_clamp(writeback_rate_fp_term_low,
341 			    dc->writeback_rate_fp_term_low,
342 			    1, dc->writeback_rate_fp_term_mid - 1);
343 	sysfs_strtoul_clamp(writeback_rate_fp_term_mid,
344 			    dc->writeback_rate_fp_term_mid,
345 			    dc->writeback_rate_fp_term_low + 1,
346 			    dc->writeback_rate_fp_term_high - 1);
347 	sysfs_strtoul_clamp(writeback_rate_fp_term_high,
348 			    dc->writeback_rate_fp_term_high,
349 			    dc->writeback_rate_fp_term_mid + 1, UINT_MAX);
350 	sysfs_strtoul_clamp(writeback_rate_minimum,
351 			    dc->writeback_rate_minimum,
352 			    1, UINT_MAX);
353 
354 	sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);
355 
356 	if (attr == &sysfs_io_disable) {
357 		int v = strtoul_or_return(buf);
358 
359 		dc->io_disable = v ? 1 : 0;
360 	}
361 
362 	sysfs_strtoul_clamp(sequential_cutoff,
363 			    dc->sequential_cutoff,
364 			    0, UINT_MAX);
365 
366 	if (attr == &sysfs_clear_stats)
367 		bch_cache_accounting_clear(&dc->accounting);
368 
369 	if (attr == &sysfs_running &&
370 	    strtoul_or_return(buf)) {
371 		v = bch_cached_dev_run(dc);
372 		if (v)
373 			return v;
374 	}
375 
376 	if (attr == &sysfs_cache_mode) {
377 		v = __sysfs_match_string(bch_cache_modes, -1, buf);
378 		if (v < 0)
379 			return v;
380 
381 		if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
382 			SET_BDEV_CACHE_MODE(&dc->sb, v);
383 			bch_write_bdev_super(dc, NULL);
384 		}
385 	}
386 
387 	if (attr == &sysfs_readahead_cache_policy) {
388 		v = __sysfs_match_string(bch_reada_cache_policies, -1, buf);
389 		if (v < 0)
390 			return v;
391 
392 		if ((unsigned int) v != dc->cache_readahead_policy)
393 			dc->cache_readahead_policy = v;
394 	}
395 
396 	if (attr == &sysfs_stop_when_cache_set_failed) {
397 		v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
398 		if (v < 0)
399 			return v;
400 
401 		dc->stop_when_cache_set_failed = v;
402 	}
403 
404 	if (attr == &sysfs_label) {
405 		if (size > SB_LABEL_SIZE)
406 			return -EINVAL;
407 		memcpy(dc->sb.label, buf, size);
408 		if (size < SB_LABEL_SIZE)
409 			dc->sb.label[size] = '\0';
410 		if (size && dc->sb.label[size - 1] == '\n')
411 			dc->sb.label[size - 1] = '\0';
412 		bch_write_bdev_super(dc, NULL);
413 		if (dc->disk.c) {
414 			memcpy(dc->disk.c->uuids[dc->disk.id].label,
415 			       buf, SB_LABEL_SIZE);
416 			bch_uuid_write(dc->disk.c);
417 		}
418 		env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
419 		if (!env)
420 			return -ENOMEM;
421 		add_uevent_var(env, "DRIVER=bcache");
422 		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid);
423 		add_uevent_var(env, "CACHED_LABEL=%s", buf);
424 		kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj,
425 				   KOBJ_CHANGE,
426 				   env->envp);
427 		kfree(env);
428 	}
429 
430 	if (attr == &sysfs_attach) {
431 		uint8_t		set_uuid[16];
432 
433 		if (bch_parse_uuid(buf, set_uuid) < 16)
434 			return -EINVAL;
435 
436 		v = -ENOENT;
437 		list_for_each_entry(c, &bch_cache_sets, list) {
438 			v = bch_cached_dev_attach(dc, c, set_uuid);
439 			if (!v)
440 				return size;
441 		}
442 		if (v == -ENOENT)
443 			pr_err("Can't attach %s: cache set not found\n", buf);
444 		return v;
445 	}
446 
447 	if (attr == &sysfs_detach && dc->disk.c)
448 		bch_cached_dev_detach(dc);
449 
450 	if (attr == &sysfs_stop)
451 		bcache_device_stop(&dc->disk);
452 
453 	return size;
454 }
455 
456 STORE(bch_cached_dev)
457 {
458 	struct cached_dev *dc = container_of(kobj, struct cached_dev,
459 					     disk.kobj);
460 
461 	/* no user space access if system is rebooting */
462 	if (bcache_is_reboot)
463 		return -EBUSY;
464 
465 	mutex_lock(&bch_register_lock);
466 	size = __cached_dev_store(kobj, attr, buf, size);
467 
468 	if (attr == &sysfs_writeback_running) {
469 		/* dc->writeback_running changed in __cached_dev_store() */
470 		if (IS_ERR_OR_NULL(dc->writeback_thread)) {
471 			/*
472 			 * reject setting it to 1 via sysfs if writeback
473 			 * kthread is not created yet.
474 			 */
475 			if (dc->writeback_running) {
476 				dc->writeback_running = false;
477 				pr_err("%s: failed to run non-existent writeback thread\n",
478 						dc->disk.disk->disk_name);
479 			}
480 		} else
481 			/*
482 			 * writeback kthread will check if dc->writeback_running
483 			 * is true or false.
484 			 */
485 			bch_writeback_queue(dc);
486 	}
487 
488 	/*
489 	 * Only set BCACHE_DEV_WB_RUNNING when cached device attached to
490 	 * a cache set, otherwise it doesn't make sense.
491 	 */
492 	if (attr == &sysfs_writeback_percent)
493 		if ((dc->disk.c != NULL) &&
494 		    (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)))
495 			schedule_delayed_work(&dc->writeback_rate_update,
496 				      dc->writeback_rate_update_seconds * HZ);
497 
498 	mutex_unlock(&bch_register_lock);
499 	return size;
500 }
501 
502 static struct attribute *bch_cached_dev_attrs[] = {
503 	&sysfs_attach,
504 	&sysfs_detach,
505 	&sysfs_stop,
506 #if 0
507 	&sysfs_data_csum,
508 #endif
509 	&sysfs_cache_mode,
510 	&sysfs_readahead_cache_policy,
511 	&sysfs_stop_when_cache_set_failed,
512 	&sysfs_writeback_metadata,
513 	&sysfs_writeback_running,
514 	&sysfs_writeback_delay,
515 	&sysfs_writeback_percent,
516 	&sysfs_writeback_rate,
517 	&sysfs_writeback_consider_fragment,
518 	&sysfs_writeback_rate_update_seconds,
519 	&sysfs_writeback_rate_i_term_inverse,
520 	&sysfs_writeback_rate_p_term_inverse,
521 	&sysfs_writeback_rate_fp_term_low,
522 	&sysfs_writeback_rate_fp_term_mid,
523 	&sysfs_writeback_rate_fp_term_high,
524 	&sysfs_writeback_rate_minimum,
525 	&sysfs_writeback_rate_debug,
526 	&sysfs_io_errors,
527 	&sysfs_io_error_limit,
528 	&sysfs_io_disable,
529 	&sysfs_dirty_data,
530 	&sysfs_stripe_size,
531 	&sysfs_partial_stripes_expensive,
532 	&sysfs_sequential_cutoff,
533 	&sysfs_clear_stats,
534 	&sysfs_running,
535 	&sysfs_state,
536 	&sysfs_label,
537 #ifdef CONFIG_BCACHE_DEBUG
538 	&sysfs_verify,
539 	&sysfs_bypass_torture_test,
540 #endif
541 	&sysfs_backing_dev_name,
542 	&sysfs_backing_dev_uuid,
543 	NULL
544 };
545 ATTRIBUTE_GROUPS(bch_cached_dev);
546 KTYPE(bch_cached_dev);
547 
548 SHOW(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 	sysfs_printf(data_csum,	"%i", d->data_csum);
555 	sysfs_hprint(size,	u->sectors << 9);
556 
557 	if (attr == &sysfs_label) {
558 		memcpy(buf, u->label, SB_LABEL_SIZE);
559 		buf[SB_LABEL_SIZE + 1] = '\0';
560 		strcat(buf, "\n");
561 		return strlen(buf);
562 	}
563 
564 	return 0;
565 }
566 
567 STORE(__bch_flash_dev)
568 {
569 	struct bcache_device *d = container_of(kobj, struct bcache_device,
570 					       kobj);
571 	struct uuid_entry *u = &d->c->uuids[d->id];
572 
573 	/* no user space access if system is rebooting */
574 	if (bcache_is_reboot)
575 		return -EBUSY;
576 
577 	sysfs_strtoul(data_csum,	d->data_csum);
578 
579 	if (attr == &sysfs_size) {
580 		uint64_t v;
581 
582 		strtoi_h_or_return(buf, v);
583 
584 		u->sectors = v >> 9;
585 		bch_uuid_write(d->c);
586 		set_capacity(d->disk, u->sectors);
587 	}
588 
589 	if (attr == &sysfs_label) {
590 		memcpy(u->label, buf, SB_LABEL_SIZE);
591 		bch_uuid_write(d->c);
592 	}
593 
594 	if (attr == &sysfs_unregister) {
595 		set_bit(BCACHE_DEV_DETACHING, &d->flags);
596 		bcache_device_stop(d);
597 	}
598 
599 	return size;
600 }
601 STORE_LOCKED(bch_flash_dev)
602 
603 static struct attribute *bch_flash_dev_attrs[] = {
604 	&sysfs_unregister,
605 #if 0
606 	&sysfs_data_csum,
607 #endif
608 	&sysfs_label,
609 	&sysfs_size,
610 	NULL
611 };
612 ATTRIBUTE_GROUPS(bch_flash_dev);
613 KTYPE(bch_flash_dev);
614 
615 struct bset_stats_op {
616 	struct btree_op op;
617 	size_t nodes;
618 	struct bset_stats stats;
619 };
620 
621 static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b)
622 {
623 	struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op);
624 
625 	op->nodes++;
626 	bch_btree_keys_stats(&b->keys, &op->stats);
627 
628 	return MAP_CONTINUE;
629 }
630 
631 static int bch_bset_print_stats(struct cache_set *c, char *buf)
632 {
633 	struct bset_stats_op op;
634 	int ret;
635 
636 	memset(&op, 0, sizeof(op));
637 	bch_btree_op_init(&op.op, -1);
638 
639 	ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats);
640 	if (ret < 0)
641 		return ret;
642 
643 	return snprintf(buf, PAGE_SIZE,
644 			"btree nodes:		%zu\n"
645 			"written sets:		%zu\n"
646 			"unwritten sets:		%zu\n"
647 			"written key bytes:	%zu\n"
648 			"unwritten key bytes:	%zu\n"
649 			"floats:			%zu\n"
650 			"failed:			%zu\n",
651 			op.nodes,
652 			op.stats.sets_written, op.stats.sets_unwritten,
653 			op.stats.bytes_written, op.stats.bytes_unwritten,
654 			op.stats.floats, op.stats.failed);
655 }
656 
657 static unsigned int bch_root_usage(struct cache_set *c)
658 {
659 	unsigned int bytes = 0;
660 	struct bkey *k;
661 	struct btree *b;
662 	struct btree_iter_stack iter;
663 
664 	goto lock_root;
665 
666 	do {
667 		rw_unlock(false, b);
668 lock_root:
669 		b = c->root;
670 		rw_lock(false, b, b->level);
671 	} while (b != c->root);
672 
673 	for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
674 		bytes += bkey_bytes(k);
675 
676 	rw_unlock(false, b);
677 
678 	return (bytes * 100) / btree_bytes(c);
679 }
680 
681 static size_t bch_cache_size(struct cache_set *c)
682 {
683 	size_t ret = 0;
684 	struct btree *b;
685 
686 	mutex_lock(&c->bucket_lock);
687 	list_for_each_entry(b, &c->btree_cache, list)
688 		ret += 1 << (b->keys.page_order + PAGE_SHIFT);
689 
690 	mutex_unlock(&c->bucket_lock);
691 	return ret;
692 }
693 
694 static unsigned int bch_cache_max_chain(struct cache_set *c)
695 {
696 	unsigned int ret = 0;
697 	struct hlist_head *h;
698 
699 	mutex_lock(&c->bucket_lock);
700 
701 	for (h = c->bucket_hash;
702 	     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
703 	     h++) {
704 		ret = max(ret, hlist_count_nodes(h));
705 	}
706 
707 	mutex_unlock(&c->bucket_lock);
708 	return ret;
709 }
710 
711 static unsigned int bch_btree_used(struct cache_set *c)
712 {
713 	return div64_u64(c->gc_stats.key_bytes * 100,
714 			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
715 }
716 
717 static unsigned int bch_average_key_size(struct cache_set *c)
718 {
719 	return c->gc_stats.nkeys
720 		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
721 		: 0;
722 }
723 
724 SHOW(__bch_cache_set)
725 {
726 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
727 
728 	sysfs_print(synchronous,		CACHE_SYNC(&c->cache->sb));
729 	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
730 	sysfs_hprint(bucket_size,		bucket_bytes(c->cache));
731 	sysfs_hprint(block_size,		block_bytes(c->cache));
732 	sysfs_print(tree_depth,			c->root->level);
733 	sysfs_print(root_usage_percent,		bch_root_usage(c));
734 
735 	sysfs_hprint(btree_cache_size,		bch_cache_size(c));
736 	sysfs_print(btree_cache_max_chain,	bch_cache_max_chain(c));
737 	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
738 
739 	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
740 	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
741 	sysfs_print_time_stats(&c->sort.time,		btree_sort, ms, us);
742 	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
743 
744 	sysfs_print(btree_used_percent,	bch_btree_used(c));
745 	sysfs_print(btree_nodes,	c->gc_stats.nodes);
746 	sysfs_hprint(average_key_size,	bch_average_key_size(c));
747 
748 	sysfs_print(cache_read_races,
749 		    atomic_long_read(&c->cache_read_races));
750 
751 	sysfs_print(reclaim,
752 		    atomic_long_read(&c->reclaim));
753 
754 	sysfs_print(reclaimed_journal_buckets,
755 		    atomic_long_read(&c->reclaimed_journal_buckets));
756 
757 	sysfs_print(flush_write,
758 		    atomic_long_read(&c->flush_write));
759 
760 	sysfs_print(writeback_keys_done,
761 		    atomic_long_read(&c->writeback_keys_done));
762 	sysfs_print(writeback_keys_failed,
763 		    atomic_long_read(&c->writeback_keys_failed));
764 
765 	if (attr == &sysfs_errors)
766 		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
767 					       c->on_error);
768 
769 	/* See count_io_errors for why 88 */
770 	sysfs_print(io_error_halflife,	c->error_decay * 88);
771 	sysfs_print(io_error_limit,	c->error_limit);
772 
773 	sysfs_hprint(congested,
774 		     ((uint64_t) bch_get_congested(c)) << 9);
775 	sysfs_print(congested_read_threshold_us,
776 		    c->congested_read_threshold_us);
777 	sysfs_print(congested_write_threshold_us,
778 		    c->congested_write_threshold_us);
779 
780 	sysfs_print(cutoff_writeback, bch_cutoff_writeback);
781 	sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync);
782 
783 	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
784 	sysfs_printf(verify,			"%i", c->verify);
785 	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
786 	sysfs_printf(expensive_debug_checks,
787 		     "%i", c->expensive_debug_checks);
788 	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
789 	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
790 	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
791 	sysfs_printf(idle_max_writeback_rate,	"%i",
792 		     c->idle_max_writeback_rate_enabled);
793 	sysfs_printf(gc_after_writeback,	"%i", c->gc_after_writeback);
794 	sysfs_printf(io_disable,		"%i",
795 		     test_bit(CACHE_SET_IO_DISABLE, &c->flags));
796 
797 	if (attr == &sysfs_bset_tree_stats)
798 		return bch_bset_print_stats(c, buf);
799 
800 	if (attr == &sysfs_feature_compat)
801 		return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE);
802 	if (attr == &sysfs_feature_ro_compat)
803 		return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE);
804 	if (attr == &sysfs_feature_incompat)
805 		return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE);
806 
807 	return 0;
808 }
809 SHOW_LOCKED(bch_cache_set)
810 
811 STORE(__bch_cache_set)
812 {
813 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
814 	ssize_t v;
815 
816 	/* no user space access if system is rebooting */
817 	if (bcache_is_reboot)
818 		return -EBUSY;
819 
820 	if (attr == &sysfs_unregister)
821 		bch_cache_set_unregister(c);
822 
823 	if (attr == &sysfs_stop)
824 		bch_cache_set_stop(c);
825 
826 	if (attr == &sysfs_synchronous) {
827 		bool sync = strtoul_or_return(buf);
828 
829 		if (sync != CACHE_SYNC(&c->cache->sb)) {
830 			SET_CACHE_SYNC(&c->cache->sb, sync);
831 			bcache_write_super(c);
832 		}
833 	}
834 
835 	if (attr == &sysfs_flash_vol_create) {
836 		int r;
837 		uint64_t v;
838 
839 		strtoi_h_or_return(buf, v);
840 
841 		r = bch_flash_dev_create(c, v);
842 		if (r)
843 			return r;
844 	}
845 
846 	if (attr == &sysfs_clear_stats) {
847 		atomic_long_set(&c->writeback_keys_done,	0);
848 		atomic_long_set(&c->writeback_keys_failed,	0);
849 
850 		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
851 		bch_cache_accounting_clear(&c->accounting);
852 	}
853 
854 	if (attr == &sysfs_trigger_gc)
855 		force_wake_up_gc(c);
856 
857 	if (attr == &sysfs_prune_cache) {
858 		struct shrink_control sc;
859 
860 		sc.gfp_mask = GFP_KERNEL;
861 		sc.nr_to_scan = strtoul_or_return(buf);
862 		if (c->shrink)
863 			c->shrink->scan_objects(c->shrink, &sc);
864 	}
865 
866 	sysfs_strtoul_clamp(congested_read_threshold_us,
867 			    c->congested_read_threshold_us,
868 			    0, UINT_MAX);
869 	sysfs_strtoul_clamp(congested_write_threshold_us,
870 			    c->congested_write_threshold_us,
871 			    0, UINT_MAX);
872 
873 	if (attr == &sysfs_errors) {
874 		v = __sysfs_match_string(error_actions, -1, buf);
875 		if (v < 0)
876 			return v;
877 
878 		c->on_error = v;
879 	}
880 
881 	sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
882 
883 	/* See count_io_errors() for why 88 */
884 	if (attr == &sysfs_io_error_halflife) {
885 		unsigned long v = 0;
886 		ssize_t ret;
887 
888 		ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX);
889 		if (!ret) {
890 			c->error_decay = v / 88;
891 			return size;
892 		}
893 		return ret;
894 	}
895 
896 	if (attr == &sysfs_io_disable) {
897 		v = strtoul_or_return(buf);
898 		if (v) {
899 			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
900 					     &c->flags))
901 				pr_warn("CACHE_SET_IO_DISABLE already set\n");
902 		} else {
903 			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
904 						&c->flags))
905 				pr_warn("CACHE_SET_IO_DISABLE already cleared\n");
906 		}
907 	}
908 
909 	sysfs_strtoul_clamp(journal_delay_ms,
910 			    c->journal_delay_ms,
911 			    0, USHRT_MAX);
912 	sysfs_strtoul_bool(verify,		c->verify);
913 	sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
914 	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
915 	sysfs_strtoul_bool(gc_always_rewrite,	c->gc_always_rewrite);
916 	sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
917 	sysfs_strtoul_bool(copy_gc_enabled,	c->copy_gc_enabled);
918 	sysfs_strtoul_bool(idle_max_writeback_rate,
919 			   c->idle_max_writeback_rate_enabled);
920 
921 	/*
922 	 * write gc_after_writeback here may overwrite an already set
923 	 * BCH_DO_AUTO_GC, it doesn't matter because this flag will be
924 	 * set in next chance.
925 	 */
926 	sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1);
927 
928 	return size;
929 }
930 STORE_LOCKED(bch_cache_set)
931 
932 SHOW(bch_cache_set_internal)
933 {
934 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
935 
936 	return bch_cache_set_show(&c->kobj, attr, buf);
937 }
938 
939 STORE(bch_cache_set_internal)
940 {
941 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
942 
943 	/* no user space access if system is rebooting */
944 	if (bcache_is_reboot)
945 		return -EBUSY;
946 
947 	return bch_cache_set_store(&c->kobj, attr, buf, size);
948 }
949 
950 static void bch_cache_set_internal_release(struct kobject *k)
951 {
952 }
953 
954 static struct attribute *bch_cache_set_attrs[] = {
955 	&sysfs_unregister,
956 	&sysfs_stop,
957 	&sysfs_synchronous,
958 	&sysfs_journal_delay_ms,
959 	&sysfs_flash_vol_create,
960 
961 	&sysfs_bucket_size,
962 	&sysfs_block_size,
963 	&sysfs_tree_depth,
964 	&sysfs_root_usage_percent,
965 	&sysfs_btree_cache_size,
966 	&sysfs_cache_available_percent,
967 
968 	&sysfs_average_key_size,
969 
970 	&sysfs_errors,
971 	&sysfs_io_error_limit,
972 	&sysfs_io_error_halflife,
973 	&sysfs_congested,
974 	&sysfs_congested_read_threshold_us,
975 	&sysfs_congested_write_threshold_us,
976 	&sysfs_clear_stats,
977 	NULL
978 };
979 ATTRIBUTE_GROUPS(bch_cache_set);
980 KTYPE(bch_cache_set);
981 
982 static struct attribute *bch_cache_set_internal_attrs[] = {
983 	&sysfs_active_journal_entries,
984 
985 	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
986 	sysfs_time_stats_attribute_list(btree_split, sec, us)
987 	sysfs_time_stats_attribute_list(btree_sort, ms, us)
988 	sysfs_time_stats_attribute_list(btree_read, ms, us)
989 
990 	&sysfs_btree_nodes,
991 	&sysfs_btree_used_percent,
992 	&sysfs_btree_cache_max_chain,
993 
994 	&sysfs_bset_tree_stats,
995 	&sysfs_cache_read_races,
996 	&sysfs_reclaim,
997 	&sysfs_reclaimed_journal_buckets,
998 	&sysfs_flush_write,
999 	&sysfs_writeback_keys_done,
1000 	&sysfs_writeback_keys_failed,
1001 
1002 	&sysfs_trigger_gc,
1003 	&sysfs_prune_cache,
1004 #ifdef CONFIG_BCACHE_DEBUG
1005 	&sysfs_verify,
1006 	&sysfs_key_merging_disabled,
1007 	&sysfs_expensive_debug_checks,
1008 #endif
1009 	&sysfs_gc_always_rewrite,
1010 	&sysfs_btree_shrinker_disabled,
1011 	&sysfs_copy_gc_enabled,
1012 	&sysfs_idle_max_writeback_rate,
1013 	&sysfs_gc_after_writeback,
1014 	&sysfs_io_disable,
1015 	&sysfs_cutoff_writeback,
1016 	&sysfs_cutoff_writeback_sync,
1017 	&sysfs_feature_compat,
1018 	&sysfs_feature_ro_compat,
1019 	&sysfs_feature_incompat,
1020 	NULL
1021 };
1022 ATTRIBUTE_GROUPS(bch_cache_set_internal);
1023 KTYPE(bch_cache_set_internal);
1024 
1025 static int __bch_cache_cmp(const void *l, const void *r)
1026 {
1027 	cond_resched();
1028 	return *((uint16_t *)r) - *((uint16_t *)l);
1029 }
1030 
1031 SHOW(__bch_cache)
1032 {
1033 	struct cache *ca = container_of(kobj, struct cache, kobj);
1034 
1035 	sysfs_hprint(bucket_size,	bucket_bytes(ca));
1036 	sysfs_hprint(block_size,	block_bytes(ca));
1037 	sysfs_print(nbuckets,		ca->sb.nbuckets);
1038 	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
1039 	sysfs_hprint(btree_written,
1040 		     atomic_long_read(&ca->btree_sectors_written) << 9);
1041 	sysfs_hprint(metadata_written,
1042 		     (atomic_long_read(&ca->meta_sectors_written) +
1043 		      atomic_long_read(&ca->btree_sectors_written)) << 9);
1044 
1045 	sysfs_print(io_errors,
1046 		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
1047 
1048 	if (attr == &sysfs_cache_replacement_policy)
1049 		return bch_snprint_string_list(buf, PAGE_SIZE,
1050 					       cache_replacement_policies,
1051 					       CACHE_REPLACEMENT(&ca->sb));
1052 
1053 	if (attr == &sysfs_priority_stats) {
1054 		struct bucket *b;
1055 		size_t n = ca->sb.nbuckets, i;
1056 		size_t unused = 0, available = 0, dirty = 0, meta = 0;
1057 		uint64_t sum = 0;
1058 		/* Compute 31 quantiles */
1059 		uint16_t q[31], *p, *cached;
1060 		ssize_t ret;
1061 
1062 		cached = p = vmalloc(array_size(sizeof(uint16_t),
1063 						ca->sb.nbuckets));
1064 		if (!p)
1065 			return -ENOMEM;
1066 
1067 		mutex_lock(&ca->set->bucket_lock);
1068 		for_each_bucket(b, ca) {
1069 			if (!GC_SECTORS_USED(b))
1070 				unused++;
1071 			if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
1072 				available++;
1073 			if (GC_MARK(b) == GC_MARK_DIRTY)
1074 				dirty++;
1075 			if (GC_MARK(b) == GC_MARK_METADATA)
1076 				meta++;
1077 		}
1078 
1079 		for (i = ca->sb.first_bucket; i < n; i++)
1080 			p[i] = ca->buckets[i].prio;
1081 		mutex_unlock(&ca->set->bucket_lock);
1082 
1083 		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
1084 
1085 		while (n &&
1086 		       !cached[n - 1])
1087 			--n;
1088 
1089 		while (cached < p + n &&
1090 		       *cached == BTREE_PRIO) {
1091 			cached++;
1092 			n--;
1093 		}
1094 
1095 		for (i = 0; i < n; i++)
1096 			sum += INITIAL_PRIO - cached[i];
1097 
1098 		if (n)
1099 			sum = div64_u64(sum, n);
1100 
1101 		for (i = 0; i < ARRAY_SIZE(q); i++)
1102 			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
1103 				(ARRAY_SIZE(q) + 1)];
1104 
1105 		vfree(p);
1106 
1107 		ret = sysfs_emit(buf,
1108 				 "Unused:		%zu%%\n"
1109 				 "Clean:		%zu%%\n"
1110 				 "Dirty:		%zu%%\n"
1111 				 "Metadata:	%zu%%\n"
1112 				 "Average:	%llu\n"
1113 				 "Sectors per Q:	%zu\n"
1114 				 "Quantiles:	[",
1115 				 unused * 100 / (size_t) ca->sb.nbuckets,
1116 				 available * 100 / (size_t) ca->sb.nbuckets,
1117 				 dirty * 100 / (size_t) ca->sb.nbuckets,
1118 				 meta * 100 / (size_t) ca->sb.nbuckets, sum,
1119 				 n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
1120 
1121 		for (i = 0; i < ARRAY_SIZE(q); i++)
1122 			ret += sysfs_emit_at(buf, ret, "%u ", q[i]);
1123 		ret--;
1124 
1125 		ret += sysfs_emit_at(buf, ret, "]\n");
1126 
1127 		return ret;
1128 	}
1129 
1130 	return 0;
1131 }
1132 SHOW_LOCKED(bch_cache)
1133 
1134 STORE(__bch_cache)
1135 {
1136 	struct cache *ca = container_of(kobj, struct cache, kobj);
1137 	ssize_t v;
1138 
1139 	/* no user space access if system is rebooting */
1140 	if (bcache_is_reboot)
1141 		return -EBUSY;
1142 
1143 	if (attr == &sysfs_cache_replacement_policy) {
1144 		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
1145 		if (v < 0)
1146 			return v;
1147 
1148 		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
1149 			mutex_lock(&ca->set->bucket_lock);
1150 			SET_CACHE_REPLACEMENT(&ca->sb, v);
1151 			mutex_unlock(&ca->set->bucket_lock);
1152 
1153 			bcache_write_super(ca->set);
1154 		}
1155 	}
1156 
1157 	if (attr == &sysfs_clear_stats) {
1158 		atomic_long_set(&ca->sectors_written, 0);
1159 		atomic_long_set(&ca->btree_sectors_written, 0);
1160 		atomic_long_set(&ca->meta_sectors_written, 0);
1161 		atomic_set(&ca->io_count, 0);
1162 		atomic_set(&ca->io_errors, 0);
1163 	}
1164 
1165 	return size;
1166 }
1167 STORE_LOCKED(bch_cache)
1168 
1169 static struct attribute *bch_cache_attrs[] = {
1170 	&sysfs_bucket_size,
1171 	&sysfs_block_size,
1172 	&sysfs_nbuckets,
1173 	&sysfs_priority_stats,
1174 	&sysfs_written,
1175 	&sysfs_btree_written,
1176 	&sysfs_metadata_written,
1177 	&sysfs_io_errors,
1178 	&sysfs_clear_stats,
1179 	&sysfs_cache_replacement_policy,
1180 	NULL
1181 };
1182 ATTRIBUTE_GROUPS(bch_cache);
1183 KTYPE(bch_cache);
1184