xref: /openbmc/linux/drivers/md/bcache/sysfs.c (revision 2ae1beb3)
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(discard);
138 rw_attribute(running);
139 rw_attribute(label);
140 rw_attribute(errors);
141 rw_attribute(io_error_limit);
142 rw_attribute(io_error_halflife);
143 rw_attribute(verify);
144 rw_attribute(bypass_torture_test);
145 rw_attribute(key_merging_disabled);
146 rw_attribute(gc_always_rewrite);
147 rw_attribute(expensive_debug_checks);
148 rw_attribute(cache_replacement_policy);
149 rw_attribute(btree_shrinker_disabled);
150 rw_attribute(copy_gc_enabled);
151 rw_attribute(idle_max_writeback_rate);
152 rw_attribute(gc_after_writeback);
153 rw_attribute(size);
154 
155 static 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 
171 SHOW(__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 }
289 SHOW_LOCKED(bch_cached_dev)
290 
291 STORE(__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 
457 STORE(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 
503 static 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 };
546 ATTRIBUTE_GROUPS(bch_cached_dev);
547 KTYPE(bch_cached_dev);
548 
549 SHOW(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 
568 STORE(__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 }
602 STORE_LOCKED(bch_flash_dev)
603 
604 static 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 };
613 ATTRIBUTE_GROUPS(bch_flash_dev);
614 KTYPE(bch_flash_dev);
615 
616 struct bset_stats_op {
617 	struct btree_op op;
618 	size_t nodes;
619 	struct bset_stats stats;
620 };
621 
622 static 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 
632 static 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 
658 static 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_stack iter;
664 
665 	goto lock_root;
666 
667 	do {
668 		rw_unlock(false, b);
669 lock_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 
682 static 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 
695 static 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 		unsigned int i = 0;
706 		struct hlist_node *p;
707 
708 		hlist_for_each(p, h)
709 			i++;
710 
711 		ret = max(ret, i);
712 	}
713 
714 	mutex_unlock(&c->bucket_lock);
715 	return ret;
716 }
717 
718 static unsigned int bch_btree_used(struct cache_set *c)
719 {
720 	return div64_u64(c->gc_stats.key_bytes * 100,
721 			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
722 }
723 
724 static unsigned int bch_average_key_size(struct cache_set *c)
725 {
726 	return c->gc_stats.nkeys
727 		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
728 		: 0;
729 }
730 
731 SHOW(__bch_cache_set)
732 {
733 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
734 
735 	sysfs_print(synchronous,		CACHE_SYNC(&c->cache->sb));
736 	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
737 	sysfs_hprint(bucket_size,		bucket_bytes(c->cache));
738 	sysfs_hprint(block_size,		block_bytes(c->cache));
739 	sysfs_print(tree_depth,			c->root->level);
740 	sysfs_print(root_usage_percent,		bch_root_usage(c));
741 
742 	sysfs_hprint(btree_cache_size,		bch_cache_size(c));
743 	sysfs_print(btree_cache_max_chain,	bch_cache_max_chain(c));
744 	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
745 
746 	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
747 	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
748 	sysfs_print_time_stats(&c->sort.time,		btree_sort, ms, us);
749 	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
750 
751 	sysfs_print(btree_used_percent,	bch_btree_used(c));
752 	sysfs_print(btree_nodes,	c->gc_stats.nodes);
753 	sysfs_hprint(average_key_size,	bch_average_key_size(c));
754 
755 	sysfs_print(cache_read_races,
756 		    atomic_long_read(&c->cache_read_races));
757 
758 	sysfs_print(reclaim,
759 		    atomic_long_read(&c->reclaim));
760 
761 	sysfs_print(reclaimed_journal_buckets,
762 		    atomic_long_read(&c->reclaimed_journal_buckets));
763 
764 	sysfs_print(flush_write,
765 		    atomic_long_read(&c->flush_write));
766 
767 	sysfs_print(writeback_keys_done,
768 		    atomic_long_read(&c->writeback_keys_done));
769 	sysfs_print(writeback_keys_failed,
770 		    atomic_long_read(&c->writeback_keys_failed));
771 
772 	if (attr == &sysfs_errors)
773 		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
774 					       c->on_error);
775 
776 	/* See count_io_errors for why 88 */
777 	sysfs_print(io_error_halflife,	c->error_decay * 88);
778 	sysfs_print(io_error_limit,	c->error_limit);
779 
780 	sysfs_hprint(congested,
781 		     ((uint64_t) bch_get_congested(c)) << 9);
782 	sysfs_print(congested_read_threshold_us,
783 		    c->congested_read_threshold_us);
784 	sysfs_print(congested_write_threshold_us,
785 		    c->congested_write_threshold_us);
786 
787 	sysfs_print(cutoff_writeback, bch_cutoff_writeback);
788 	sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync);
789 
790 	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
791 	sysfs_printf(verify,			"%i", c->verify);
792 	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
793 	sysfs_printf(expensive_debug_checks,
794 		     "%i", c->expensive_debug_checks);
795 	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
796 	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
797 	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
798 	sysfs_printf(idle_max_writeback_rate,	"%i",
799 		     c->idle_max_writeback_rate_enabled);
800 	sysfs_printf(gc_after_writeback,	"%i", c->gc_after_writeback);
801 	sysfs_printf(io_disable,		"%i",
802 		     test_bit(CACHE_SET_IO_DISABLE, &c->flags));
803 
804 	if (attr == &sysfs_bset_tree_stats)
805 		return bch_bset_print_stats(c, buf);
806 
807 	if (attr == &sysfs_feature_compat)
808 		return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE);
809 	if (attr == &sysfs_feature_ro_compat)
810 		return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE);
811 	if (attr == &sysfs_feature_incompat)
812 		return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE);
813 
814 	return 0;
815 }
816 SHOW_LOCKED(bch_cache_set)
817 
818 STORE(__bch_cache_set)
819 {
820 	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
821 	ssize_t v;
822 
823 	/* no user space access if system is rebooting */
824 	if (bcache_is_reboot)
825 		return -EBUSY;
826 
827 	if (attr == &sysfs_unregister)
828 		bch_cache_set_unregister(c);
829 
830 	if (attr == &sysfs_stop)
831 		bch_cache_set_stop(c);
832 
833 	if (attr == &sysfs_synchronous) {
834 		bool sync = strtoul_or_return(buf);
835 
836 		if (sync != CACHE_SYNC(&c->cache->sb)) {
837 			SET_CACHE_SYNC(&c->cache->sb, sync);
838 			bcache_write_super(c);
839 		}
840 	}
841 
842 	if (attr == &sysfs_flash_vol_create) {
843 		int r;
844 		uint64_t v;
845 
846 		strtoi_h_or_return(buf, v);
847 
848 		r = bch_flash_dev_create(c, v);
849 		if (r)
850 			return r;
851 	}
852 
853 	if (attr == &sysfs_clear_stats) {
854 		atomic_long_set(&c->writeback_keys_done,	0);
855 		atomic_long_set(&c->writeback_keys_failed,	0);
856 
857 		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
858 		bch_cache_accounting_clear(&c->accounting);
859 	}
860 
861 	if (attr == &sysfs_trigger_gc)
862 		force_wake_up_gc(c);
863 
864 	if (attr == &sysfs_prune_cache) {
865 		struct shrink_control sc;
866 
867 		sc.gfp_mask = GFP_KERNEL;
868 		sc.nr_to_scan = strtoul_or_return(buf);
869 		c->shrink.scan_objects(&c->shrink, &sc);
870 	}
871 
872 	sysfs_strtoul_clamp(congested_read_threshold_us,
873 			    c->congested_read_threshold_us,
874 			    0, UINT_MAX);
875 	sysfs_strtoul_clamp(congested_write_threshold_us,
876 			    c->congested_write_threshold_us,
877 			    0, UINT_MAX);
878 
879 	if (attr == &sysfs_errors) {
880 		v = __sysfs_match_string(error_actions, -1, buf);
881 		if (v < 0)
882 			return v;
883 
884 		c->on_error = v;
885 	}
886 
887 	sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
888 
889 	/* See count_io_errors() for why 88 */
890 	if (attr == &sysfs_io_error_halflife) {
891 		unsigned long v = 0;
892 		ssize_t ret;
893 
894 		ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX);
895 		if (!ret) {
896 			c->error_decay = v / 88;
897 			return size;
898 		}
899 		return ret;
900 	}
901 
902 	if (attr == &sysfs_io_disable) {
903 		v = strtoul_or_return(buf);
904 		if (v) {
905 			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
906 					     &c->flags))
907 				pr_warn("CACHE_SET_IO_DISABLE already set\n");
908 		} else {
909 			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
910 						&c->flags))
911 				pr_warn("CACHE_SET_IO_DISABLE already cleared\n");
912 		}
913 	}
914 
915 	sysfs_strtoul_clamp(journal_delay_ms,
916 			    c->journal_delay_ms,
917 			    0, USHRT_MAX);
918 	sysfs_strtoul_bool(verify,		c->verify);
919 	sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
920 	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
921 	sysfs_strtoul_bool(gc_always_rewrite,	c->gc_always_rewrite);
922 	sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
923 	sysfs_strtoul_bool(copy_gc_enabled,	c->copy_gc_enabled);
924 	sysfs_strtoul_bool(idle_max_writeback_rate,
925 			   c->idle_max_writeback_rate_enabled);
926 
927 	/*
928 	 * write gc_after_writeback here may overwrite an already set
929 	 * BCH_DO_AUTO_GC, it doesn't matter because this flag will be
930 	 * set in next chance.
931 	 */
932 	sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1);
933 
934 	return size;
935 }
936 STORE_LOCKED(bch_cache_set)
937 
938 SHOW(bch_cache_set_internal)
939 {
940 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
941 
942 	return bch_cache_set_show(&c->kobj, attr, buf);
943 }
944 
945 STORE(bch_cache_set_internal)
946 {
947 	struct cache_set *c = container_of(kobj, struct cache_set, internal);
948 
949 	/* no user space access if system is rebooting */
950 	if (bcache_is_reboot)
951 		return -EBUSY;
952 
953 	return bch_cache_set_store(&c->kobj, attr, buf, size);
954 }
955 
956 static void bch_cache_set_internal_release(struct kobject *k)
957 {
958 }
959 
960 static struct attribute *bch_cache_set_attrs[] = {
961 	&sysfs_unregister,
962 	&sysfs_stop,
963 	&sysfs_synchronous,
964 	&sysfs_journal_delay_ms,
965 	&sysfs_flash_vol_create,
966 
967 	&sysfs_bucket_size,
968 	&sysfs_block_size,
969 	&sysfs_tree_depth,
970 	&sysfs_root_usage_percent,
971 	&sysfs_btree_cache_size,
972 	&sysfs_cache_available_percent,
973 
974 	&sysfs_average_key_size,
975 
976 	&sysfs_errors,
977 	&sysfs_io_error_limit,
978 	&sysfs_io_error_halflife,
979 	&sysfs_congested,
980 	&sysfs_congested_read_threshold_us,
981 	&sysfs_congested_write_threshold_us,
982 	&sysfs_clear_stats,
983 	NULL
984 };
985 ATTRIBUTE_GROUPS(bch_cache_set);
986 KTYPE(bch_cache_set);
987 
988 static struct attribute *bch_cache_set_internal_attrs[] = {
989 	&sysfs_active_journal_entries,
990 
991 	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
992 	sysfs_time_stats_attribute_list(btree_split, sec, us)
993 	sysfs_time_stats_attribute_list(btree_sort, ms, us)
994 	sysfs_time_stats_attribute_list(btree_read, ms, us)
995 
996 	&sysfs_btree_nodes,
997 	&sysfs_btree_used_percent,
998 	&sysfs_btree_cache_max_chain,
999 
1000 	&sysfs_bset_tree_stats,
1001 	&sysfs_cache_read_races,
1002 	&sysfs_reclaim,
1003 	&sysfs_reclaimed_journal_buckets,
1004 	&sysfs_flush_write,
1005 	&sysfs_writeback_keys_done,
1006 	&sysfs_writeback_keys_failed,
1007 
1008 	&sysfs_trigger_gc,
1009 	&sysfs_prune_cache,
1010 #ifdef CONFIG_BCACHE_DEBUG
1011 	&sysfs_verify,
1012 	&sysfs_key_merging_disabled,
1013 	&sysfs_expensive_debug_checks,
1014 #endif
1015 	&sysfs_gc_always_rewrite,
1016 	&sysfs_btree_shrinker_disabled,
1017 	&sysfs_copy_gc_enabled,
1018 	&sysfs_idle_max_writeback_rate,
1019 	&sysfs_gc_after_writeback,
1020 	&sysfs_io_disable,
1021 	&sysfs_cutoff_writeback,
1022 	&sysfs_cutoff_writeback_sync,
1023 	&sysfs_feature_compat,
1024 	&sysfs_feature_ro_compat,
1025 	&sysfs_feature_incompat,
1026 	NULL
1027 };
1028 ATTRIBUTE_GROUPS(bch_cache_set_internal);
1029 KTYPE(bch_cache_set_internal);
1030 
1031 static int __bch_cache_cmp(const void *l, const void *r)
1032 {
1033 	cond_resched();
1034 	return *((uint16_t *)r) - *((uint16_t *)l);
1035 }
1036 
1037 SHOW(__bch_cache)
1038 {
1039 	struct cache *ca = container_of(kobj, struct cache, kobj);
1040 
1041 	sysfs_hprint(bucket_size,	bucket_bytes(ca));
1042 	sysfs_hprint(block_size,	block_bytes(ca));
1043 	sysfs_print(nbuckets,		ca->sb.nbuckets);
1044 	sysfs_print(discard,		ca->discard);
1045 	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
1046 	sysfs_hprint(btree_written,
1047 		     atomic_long_read(&ca->btree_sectors_written) << 9);
1048 	sysfs_hprint(metadata_written,
1049 		     (atomic_long_read(&ca->meta_sectors_written) +
1050 		      atomic_long_read(&ca->btree_sectors_written)) << 9);
1051 
1052 	sysfs_print(io_errors,
1053 		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
1054 
1055 	if (attr == &sysfs_cache_replacement_policy)
1056 		return bch_snprint_string_list(buf, PAGE_SIZE,
1057 					       cache_replacement_policies,
1058 					       CACHE_REPLACEMENT(&ca->sb));
1059 
1060 	if (attr == &sysfs_priority_stats) {
1061 		struct bucket *b;
1062 		size_t n = ca->sb.nbuckets, i;
1063 		size_t unused = 0, available = 0, dirty = 0, meta = 0;
1064 		uint64_t sum = 0;
1065 		/* Compute 31 quantiles */
1066 		uint16_t q[31], *p, *cached;
1067 		ssize_t ret;
1068 
1069 		cached = p = vmalloc(array_size(sizeof(uint16_t),
1070 						ca->sb.nbuckets));
1071 		if (!p)
1072 			return -ENOMEM;
1073 
1074 		mutex_lock(&ca->set->bucket_lock);
1075 		for_each_bucket(b, ca) {
1076 			if (!GC_SECTORS_USED(b))
1077 				unused++;
1078 			if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
1079 				available++;
1080 			if (GC_MARK(b) == GC_MARK_DIRTY)
1081 				dirty++;
1082 			if (GC_MARK(b) == GC_MARK_METADATA)
1083 				meta++;
1084 		}
1085 
1086 		for (i = ca->sb.first_bucket; i < n; i++)
1087 			p[i] = ca->buckets[i].prio;
1088 		mutex_unlock(&ca->set->bucket_lock);
1089 
1090 		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
1091 
1092 		while (n &&
1093 		       !cached[n - 1])
1094 			--n;
1095 
1096 		while (cached < p + n &&
1097 		       *cached == BTREE_PRIO) {
1098 			cached++;
1099 			n--;
1100 		}
1101 
1102 		for (i = 0; i < n; i++)
1103 			sum += INITIAL_PRIO - cached[i];
1104 
1105 		if (n)
1106 			sum = div64_u64(sum, n);
1107 
1108 		for (i = 0; i < ARRAY_SIZE(q); i++)
1109 			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
1110 				(ARRAY_SIZE(q) + 1)];
1111 
1112 		vfree(p);
1113 
1114 		ret = sysfs_emit(buf,
1115 				 "Unused:		%zu%%\n"
1116 				 "Clean:		%zu%%\n"
1117 				 "Dirty:		%zu%%\n"
1118 				 "Metadata:	%zu%%\n"
1119 				 "Average:	%llu\n"
1120 				 "Sectors per Q:	%zu\n"
1121 				 "Quantiles:	[",
1122 				 unused * 100 / (size_t) ca->sb.nbuckets,
1123 				 available * 100 / (size_t) ca->sb.nbuckets,
1124 				 dirty * 100 / (size_t) ca->sb.nbuckets,
1125 				 meta * 100 / (size_t) ca->sb.nbuckets, sum,
1126 				 n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
1127 
1128 		for (i = 0; i < ARRAY_SIZE(q); i++)
1129 			ret += sysfs_emit_at(buf, ret, "%u ", q[i]);
1130 		ret--;
1131 
1132 		ret += sysfs_emit_at(buf, ret, "]\n");
1133 
1134 		return ret;
1135 	}
1136 
1137 	return 0;
1138 }
1139 SHOW_LOCKED(bch_cache)
1140 
1141 STORE(__bch_cache)
1142 {
1143 	struct cache *ca = container_of(kobj, struct cache, kobj);
1144 	ssize_t v;
1145 
1146 	/* no user space access if system is rebooting */
1147 	if (bcache_is_reboot)
1148 		return -EBUSY;
1149 
1150 	if (attr == &sysfs_discard) {
1151 		bool v = strtoul_or_return(buf);
1152 
1153 		if (bdev_max_discard_sectors(ca->bdev))
1154 			ca->discard = v;
1155 
1156 		if (v != CACHE_DISCARD(&ca->sb)) {
1157 			SET_CACHE_DISCARD(&ca->sb, v);
1158 			bcache_write_super(ca->set);
1159 		}
1160 	}
1161 
1162 	if (attr == &sysfs_cache_replacement_policy) {
1163 		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
1164 		if (v < 0)
1165 			return v;
1166 
1167 		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
1168 			mutex_lock(&ca->set->bucket_lock);
1169 			SET_CACHE_REPLACEMENT(&ca->sb, v);
1170 			mutex_unlock(&ca->set->bucket_lock);
1171 
1172 			bcache_write_super(ca->set);
1173 		}
1174 	}
1175 
1176 	if (attr == &sysfs_clear_stats) {
1177 		atomic_long_set(&ca->sectors_written, 0);
1178 		atomic_long_set(&ca->btree_sectors_written, 0);
1179 		atomic_long_set(&ca->meta_sectors_written, 0);
1180 		atomic_set(&ca->io_count, 0);
1181 		atomic_set(&ca->io_errors, 0);
1182 	}
1183 
1184 	return size;
1185 }
1186 STORE_LOCKED(bch_cache)
1187 
1188 static struct attribute *bch_cache_attrs[] = {
1189 	&sysfs_bucket_size,
1190 	&sysfs_block_size,
1191 	&sysfs_nbuckets,
1192 	&sysfs_priority_stats,
1193 	&sysfs_discard,
1194 	&sysfs_written,
1195 	&sysfs_btree_written,
1196 	&sysfs_metadata_written,
1197 	&sysfs_io_errors,
1198 	&sysfs_clear_stats,
1199 	&sysfs_cache_replacement_policy,
1200 	NULL
1201 };
1202 ATTRIBUTE_GROUPS(bch_cache);
1203 KTYPE(bch_cache);
1204