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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * bcache sysfs interfaces
   4 *
   5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
   6 * Copyright 2012 Google, Inc.
   7 */
   8
   9#include "bcache.h"
  10#include "sysfs.h"
  11#include "btree.h"
  12#include "request.h"
  13#include "writeback.h"
  14#include "features.h"
  15
  16#include <linux/blkdev.h>
  17#include <linux/sort.h>
  18#include <linux/sched/clock.h>
  19
  20extern bool bcache_is_reboot;
  21
  22/* Default is 0 ("writethrough") */
  23static const char * const bch_cache_modes[] = {
  24	"writethrough",
  25	"writeback",
  26	"writearound",
  27	"none",
  28	NULL
  29};
  30
  31static const char * const bch_reada_cache_policies[] = {
  32	"all",
  33	"meta-only",
  34	NULL
  35};
  36
  37/* Default is 0 ("auto") */
  38static const char * const bch_stop_on_failure_modes[] = {
  39	"auto",
  40	"always",
  41	NULL
  42};
  43
  44static const char * const cache_replacement_policies[] = {
  45	"lru",
  46	"fifo",
  47	"random",
  48	NULL
  49};
  50
  51static const char * const error_actions[] = {
  52	"unregister",
  53	"panic",
  54	NULL
  55};
  56
  57write_attribute(attach);
  58write_attribute(detach);
  59write_attribute(unregister);
  60write_attribute(stop);
  61write_attribute(clear_stats);
  62write_attribute(trigger_gc);
  63write_attribute(prune_cache);
  64write_attribute(flash_vol_create);
  65
  66read_attribute(bucket_size);
  67read_attribute(block_size);
  68read_attribute(nbuckets);
  69read_attribute(tree_depth);
  70read_attribute(root_usage_percent);
  71read_attribute(priority_stats);
  72read_attribute(btree_cache_size);
  73read_attribute(btree_cache_max_chain);
  74read_attribute(cache_available_percent);
  75read_attribute(written);
  76read_attribute(btree_written);
  77read_attribute(metadata_written);
  78read_attribute(active_journal_entries);
  79read_attribute(backing_dev_name);
  80read_attribute(backing_dev_uuid);
  81
  82sysfs_time_stats_attribute(btree_gc,	sec, ms);
  83sysfs_time_stats_attribute(btree_split, sec, us);
  84sysfs_time_stats_attribute(btree_sort,	ms,  us);
  85sysfs_time_stats_attribute(btree_read,	ms,  us);
  86
  87read_attribute(btree_nodes);
  88read_attribute(btree_used_percent);
  89read_attribute(average_key_size);
  90read_attribute(dirty_data);
  91read_attribute(bset_tree_stats);
  92read_attribute(feature_compat);
  93read_attribute(feature_ro_compat);
  94read_attribute(feature_incompat);
  95
  96read_attribute(state);
  97read_attribute(cache_read_races);
  98read_attribute(reclaim);
  99read_attribute(reclaimed_journal_buckets);
 100read_attribute(flush_write);
 101read_attribute(writeback_keys_done);
 102read_attribute(writeback_keys_failed);
 103read_attribute(io_errors);
 104read_attribute(congested);
 105read_attribute(cutoff_writeback);
 106read_attribute(cutoff_writeback_sync);
 107rw_attribute(congested_read_threshold_us);
 108rw_attribute(congested_write_threshold_us);
 109
 110rw_attribute(sequential_cutoff);
 111rw_attribute(data_csum);
 112rw_attribute(cache_mode);
 113rw_attribute(readahead_cache_policy);
 114rw_attribute(stop_when_cache_set_failed);
 115rw_attribute(writeback_metadata);
 116rw_attribute(writeback_running);
 117rw_attribute(writeback_percent);
 118rw_attribute(writeback_delay);
 119rw_attribute(writeback_rate);
 120
 121rw_attribute(writeback_rate_update_seconds);
 122rw_attribute(writeback_rate_i_term_inverse);
 123rw_attribute(writeback_rate_p_term_inverse);
 124rw_attribute(writeback_rate_minimum);
 125read_attribute(writeback_rate_debug);
 126
 127read_attribute(stripe_size);
 128read_attribute(partial_stripes_expensive);
 129
 130rw_attribute(synchronous);
 131rw_attribute(journal_delay_ms);
 132rw_attribute(io_disable);
 133rw_attribute(discard);
 134rw_attribute(running);
 135rw_attribute(label);
 136rw_attribute(readahead);
 137rw_attribute(errors);
 138rw_attribute(io_error_limit);
 139rw_attribute(io_error_halflife);
 140rw_attribute(verify);
 141rw_attribute(bypass_torture_test);
 142rw_attribute(key_merging_disabled);
 143rw_attribute(gc_always_rewrite);
 144rw_attribute(expensive_debug_checks);
 145rw_attribute(cache_replacement_policy);
 146rw_attribute(btree_shrinker_disabled);
 147rw_attribute(copy_gc_enabled);
 148rw_attribute(idle_max_writeback_rate);
 149rw_attribute(gc_after_writeback);
 150rw_attribute(size);
 151
 152static ssize_t bch_snprint_string_list(char *buf,
 153				       size_t size,
 154				       const char * const list[],
 155				       size_t selected)
 156{
 157	char *out = buf;
 158	size_t i;
 159
 160	for (i = 0; list[i]; i++)
 161		out += scnprintf(out, buf + size - out,
 162				i == selected ? "[%s] " : "%s ", list[i]);
 163
 164	out[-1] = '\n';
 165	return out - buf;
 166}
 167
 168SHOW(__bch_cached_dev)
 169{
 170	struct cached_dev *dc = container_of(kobj, struct cached_dev,
 171					     disk.kobj);
 172	char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
 173	int wb = dc->writeback_running;
 174
 175#define var(stat)		(dc->stat)
 176
 177	if (attr == &sysfs_cache_mode)
 178		return bch_snprint_string_list(buf, PAGE_SIZE,
 179					       bch_cache_modes,
 180					       BDEV_CACHE_MODE(&dc->sb));
 181
 182	if (attr == &sysfs_readahead_cache_policy)
 183		return bch_snprint_string_list(buf, PAGE_SIZE,
 184					      bch_reada_cache_policies,
 185					      dc->cache_readahead_policy);
 186
 187	if (attr == &sysfs_stop_when_cache_set_failed)
 188		return bch_snprint_string_list(buf, PAGE_SIZE,
 189					       bch_stop_on_failure_modes,
 190					       dc->stop_when_cache_set_failed);
 191
 192
 193	sysfs_printf(data_csum,		"%i", dc->disk.data_csum);
 194	var_printf(verify,		"%i");
 195	var_printf(bypass_torture_test,	"%i");
 196	var_printf(writeback_metadata,	"%i");
 197	var_printf(writeback_running,	"%i");
 198	var_print(writeback_delay);
 199	var_print(writeback_percent);
 200	sysfs_hprint(writeback_rate,
 201		     wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
 202	sysfs_printf(io_errors,		"%i", atomic_read(&dc->io_errors));
 203	sysfs_printf(io_error_limit,	"%i", dc->error_limit);
 204	sysfs_printf(io_disable,	"%i", dc->io_disable);
 205	var_print(writeback_rate_update_seconds);
 206	var_print(writeback_rate_i_term_inverse);
 207	var_print(writeback_rate_p_term_inverse);
 208	var_print(writeback_rate_minimum);
 209
 210	if (attr == &sysfs_writeback_rate_debug) {
 211		char rate[20];
 212		char dirty[20];
 213		char target[20];
 214		char proportional[20];
 215		char integral[20];
 216		char change[20];
 217		s64 next_io;
 218
 219		/*
 220		 * Except for dirty and target, other values should
 221		 * be 0 if writeback is not running.
 222		 */
 223		bch_hprint(rate,
 224			   wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
 225			      : 0);
 226		bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
 227		bch_hprint(target, dc->writeback_rate_target << 9);
 228		bch_hprint(proportional,
 229			   wb ? dc->writeback_rate_proportional << 9 : 0);
 230		bch_hprint(integral,
 231			   wb ? dc->writeback_rate_integral_scaled << 9 : 0);
 232		bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
 233		next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
 234					 NSEC_PER_MSEC) : 0;
 235
 236		return sprintf(buf,
 237			       "rate:\t\t%s/sec\n"
 238			       "dirty:\t\t%s\n"
 239			       "target:\t\t%s\n"
 240			       "proportional:\t%s\n"
 241			       "integral:\t%s\n"
 242			       "change:\t\t%s/sec\n"
 243			       "next io:\t%llims\n",
 244			       rate, dirty, target, proportional,
 245			       integral, change, next_io);
 246	}
 247
 248	sysfs_hprint(dirty_data,
 249		     bcache_dev_sectors_dirty(&dc->disk) << 9);
 250
 251	sysfs_hprint(stripe_size,	 ((uint64_t)dc->disk.stripe_size) << 9);
 252	var_printf(partial_stripes_expensive,	"%u");
 253
 254	var_hprint(sequential_cutoff);
 255	var_hprint(readahead);
 256
 257	sysfs_print(running,		atomic_read(&dc->running));
 258	sysfs_print(state,		states[BDEV_STATE(&dc->sb)]);
 259
 260	if (attr == &sysfs_label) {
 261		memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
 262		buf[SB_LABEL_SIZE + 1] = '\0';
 263		strcat(buf, "\n");
 264		return strlen(buf);
 265	}
 266
 267	if (attr == &sysfs_backing_dev_name) {
 268		snprintf(buf, BDEVNAME_SIZE + 1, "%s", dc->backing_dev_name);
 269		strcat(buf, "\n");
 270		return strlen(buf);
 271	}
 272
 273	if (attr == &sysfs_backing_dev_uuid) {
 274		/* convert binary uuid into 36-byte string plus '\0' */
 275		snprintf(buf, 36+1, "%pU", dc->sb.uuid);
 276		strcat(buf, "\n");
 277		return strlen(buf);
 278	}
 279
 280#undef var
 281	return 0;
 282}
 283SHOW_LOCKED(bch_cached_dev)
 284
 285STORE(__cached_dev)
 286{
 287	struct cached_dev *dc = container_of(kobj, struct cached_dev,
 288					     disk.kobj);
 289	ssize_t v;
 290	struct cache_set *c;
 291	struct kobj_uevent_env *env;
 292
 293	/* no user space access if system is rebooting */
 294	if (bcache_is_reboot)
 295		return -EBUSY;
 296
 297#define d_strtoul(var)		sysfs_strtoul(var, dc->var)
 298#define d_strtoul_nonzero(var)	sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
 299#define d_strtoi_h(var)		sysfs_hatoi(var, dc->var)
 300
 301	sysfs_strtoul(data_csum,	dc->disk.data_csum);
 302	d_strtoul(verify);
 303	sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test);
 304	sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata);
 305	sysfs_strtoul_bool(writeback_running, dc->writeback_running);
 306	sysfs_strtoul_clamp(writeback_delay, dc->writeback_delay, 0, UINT_MAX);
 307
 308	sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent,
 309			    0, bch_cutoff_writeback);
 310
 311	if (attr == &sysfs_writeback_rate) {
 312		ssize_t ret;
 313		long int v = atomic_long_read(&dc->writeback_rate.rate);
 314
 315		ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
 316
 317		if (!ret) {
 318			atomic_long_set(&dc->writeback_rate.rate, v);
 319			ret = size;
 320		}
 321
 322		return ret;
 323	}
 324
 325	sysfs_strtoul_clamp(writeback_rate_update_seconds,
 326			    dc->writeback_rate_update_seconds,
 327			    1, WRITEBACK_RATE_UPDATE_SECS_MAX);
 328	sysfs_strtoul_clamp(writeback_rate_i_term_inverse,
 329			    dc->writeback_rate_i_term_inverse,
 330			    1, UINT_MAX);
 331	sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
 332			    dc->writeback_rate_p_term_inverse,
 333			    1, UINT_MAX);
 334	sysfs_strtoul_clamp(writeback_rate_minimum,
 335			    dc->writeback_rate_minimum,
 336			    1, UINT_MAX);
 337
 338	sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);
 339
 340	if (attr == &sysfs_io_disable) {
 341		int v = strtoul_or_return(buf);
 342
 343		dc->io_disable = v ? 1 : 0;
 344	}
 345
 346	sysfs_strtoul_clamp(sequential_cutoff,
 347			    dc->sequential_cutoff,
 348			    0, UINT_MAX);
 349	d_strtoi_h(readahead);
 350
 351	if (attr == &sysfs_clear_stats)
 352		bch_cache_accounting_clear(&dc->accounting);
 353
 354	if (attr == &sysfs_running &&
 355	    strtoul_or_return(buf)) {
 356		v = bch_cached_dev_run(dc);
 357		if (v)
 358			return v;
 359	}
 360
 361	if (attr == &sysfs_cache_mode) {
 362		v = __sysfs_match_string(bch_cache_modes, -1, buf);
 363		if (v < 0)
 364			return v;
 365
 366		if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
 367			SET_BDEV_CACHE_MODE(&dc->sb, v);
 368			bch_write_bdev_super(dc, NULL);
 369		}
 370	}
 371
 372	if (attr == &sysfs_readahead_cache_policy) {
 373		v = __sysfs_match_string(bch_reada_cache_policies, -1, buf);
 374		if (v < 0)
 375			return v;
 376
 377		if ((unsigned int) v != dc->cache_readahead_policy)
 378			dc->cache_readahead_policy = v;
 379	}
 380
 381	if (attr == &sysfs_stop_when_cache_set_failed) {
 382		v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
 383		if (v < 0)
 384			return v;
 385
 386		dc->stop_when_cache_set_failed = v;
 387	}
 388
 389	if (attr == &sysfs_label) {
 390		if (size > SB_LABEL_SIZE)
 391			return -EINVAL;
 392		memcpy(dc->sb.label, buf, size);
 393		if (size < SB_LABEL_SIZE)
 394			dc->sb.label[size] = '\0';
 395		if (size && dc->sb.label[size - 1] == '\n')
 396			dc->sb.label[size - 1] = '\0';
 397		bch_write_bdev_super(dc, NULL);
 398		if (dc->disk.c) {
 399			memcpy(dc->disk.c->uuids[dc->disk.id].label,
 400			       buf, SB_LABEL_SIZE);
 401			bch_uuid_write(dc->disk.c);
 402		}
 403		env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 404		if (!env)
 405			return -ENOMEM;
 406		add_uevent_var(env, "DRIVER=bcache");
 407		add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
 408		add_uevent_var(env, "CACHED_LABEL=%s", buf);
 409		kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj,
 410				   KOBJ_CHANGE,
 411				   env->envp);
 412		kfree(env);
 413	}
 414
 415	if (attr == &sysfs_attach) {
 416		uint8_t		set_uuid[16];
 417
 418		if (bch_parse_uuid(buf, set_uuid) < 16)
 419			return -EINVAL;
 420
 421		v = -ENOENT;
 422		list_for_each_entry(c, &bch_cache_sets, list) {
 423			v = bch_cached_dev_attach(dc, c, set_uuid);
 424			if (!v)
 425				return size;
 426		}
 427		if (v == -ENOENT)
 428			pr_err("Can't attach %s: cache set not found\n", buf);
 429		return v;
 430	}
 431
 432	if (attr == &sysfs_detach && dc->disk.c)
 433		bch_cached_dev_detach(dc);
 434
 435	if (attr == &sysfs_stop)
 436		bcache_device_stop(&dc->disk);
 437
 438	return size;
 439}
 440
 441STORE(bch_cached_dev)
 442{
 443	struct cached_dev *dc = container_of(kobj, struct cached_dev,
 444					     disk.kobj);
 445
 446	/* no user space access if system is rebooting */
 447	if (bcache_is_reboot)
 448		return -EBUSY;
 449
 450	mutex_lock(&bch_register_lock);
 451	size = __cached_dev_store(kobj, attr, buf, size);
 452
 453	if (attr == &sysfs_writeback_running) {
 454		/* dc->writeback_running changed in __cached_dev_store() */
 455		if (IS_ERR_OR_NULL(dc->writeback_thread)) {
 456			/*
 457			 * reject setting it to 1 via sysfs if writeback
 458			 * kthread is not created yet.
 459			 */
 460			if (dc->writeback_running) {
 461				dc->writeback_running = false;
 462				pr_err("%s: failed to run non-existent writeback thread\n",
 463						dc->disk.disk->disk_name);
 464			}
 465		} else
 466			/*
 467			 * writeback kthread will check if dc->writeback_running
 468			 * is true or false.
 469			 */
 470			bch_writeback_queue(dc);
 471	}
 472
 473	/*
 474	 * Only set BCACHE_DEV_WB_RUNNING when cached device attached to
 475	 * a cache set, otherwise it doesn't make sense.
 476	 */
 477	if (attr == &sysfs_writeback_percent)
 478		if ((dc->disk.c != NULL) &&
 479		    (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)))
 480			schedule_delayed_work(&dc->writeback_rate_update,
 481				      dc->writeback_rate_update_seconds * HZ);
 482
 483	mutex_unlock(&bch_register_lock);
 484	return size;
 485}
 486
 487static struct attribute *bch_cached_dev_files[] = {
 488	&sysfs_attach,
 489	&sysfs_detach,
 490	&sysfs_stop,
 491#if 0
 492	&sysfs_data_csum,
 493#endif
 494	&sysfs_cache_mode,
 495	&sysfs_readahead_cache_policy,
 496	&sysfs_stop_when_cache_set_failed,
 497	&sysfs_writeback_metadata,
 498	&sysfs_writeback_running,
 499	&sysfs_writeback_delay,
 500	&sysfs_writeback_percent,
 501	&sysfs_writeback_rate,
 502	&sysfs_writeback_rate_update_seconds,
 503	&sysfs_writeback_rate_i_term_inverse,
 504	&sysfs_writeback_rate_p_term_inverse,
 505	&sysfs_writeback_rate_minimum,
 506	&sysfs_writeback_rate_debug,
 507	&sysfs_io_errors,
 508	&sysfs_io_error_limit,
 509	&sysfs_io_disable,
 510	&sysfs_dirty_data,
 511	&sysfs_stripe_size,
 512	&sysfs_partial_stripes_expensive,
 513	&sysfs_sequential_cutoff,
 514	&sysfs_clear_stats,
 515	&sysfs_running,
 516	&sysfs_state,
 517	&sysfs_label,
 518	&sysfs_readahead,
 519#ifdef CONFIG_BCACHE_DEBUG
 520	&sysfs_verify,
 521	&sysfs_bypass_torture_test,
 522#endif
 523	&sysfs_backing_dev_name,
 524	&sysfs_backing_dev_uuid,
 525	NULL
 526};
 527KTYPE(bch_cached_dev);
 528
 529SHOW(bch_flash_dev)
 530{
 531	struct bcache_device *d = container_of(kobj, struct bcache_device,
 532					       kobj);
 533	struct uuid_entry *u = &d->c->uuids[d->id];
 534
 535	sysfs_printf(data_csum,	"%i", d->data_csum);
 536	sysfs_hprint(size,	u->sectors << 9);
 537
 538	if (attr == &sysfs_label) {
 539		memcpy(buf, u->label, SB_LABEL_SIZE);
 540		buf[SB_LABEL_SIZE + 1] = '\0';
 541		strcat(buf, "\n");
 542		return strlen(buf);
 543	}
 544
 545	return 0;
 546}
 547
 548STORE(__bch_flash_dev)
 549{
 550	struct bcache_device *d = container_of(kobj, struct bcache_device,
 551					       kobj);
 552	struct uuid_entry *u = &d->c->uuids[d->id];
 553
 554	/* no user space access if system is rebooting */
 555	if (bcache_is_reboot)
 556		return -EBUSY;
 557
 558	sysfs_strtoul(data_csum,	d->data_csum);
 559
 560	if (attr == &sysfs_size) {
 561		uint64_t v;
 562
 563		strtoi_h_or_return(buf, v);
 564
 565		u->sectors = v >> 9;
 566		bch_uuid_write(d->c);
 567		set_capacity(d->disk, u->sectors);
 568	}
 569
 570	if (attr == &sysfs_label) {
 571		memcpy(u->label, buf, SB_LABEL_SIZE);
 572		bch_uuid_write(d->c);
 573	}
 574
 575	if (attr == &sysfs_unregister) {
 576		set_bit(BCACHE_DEV_DETACHING, &d->flags);
 577		bcache_device_stop(d);
 578	}
 579
 580	return size;
 581}
 582STORE_LOCKED(bch_flash_dev)
 583
 584static struct attribute *bch_flash_dev_files[] = {
 585	&sysfs_unregister,
 586#if 0
 587	&sysfs_data_csum,
 588#endif
 589	&sysfs_label,
 590	&sysfs_size,
 591	NULL
 592};
 593KTYPE(bch_flash_dev);
 594
 595struct bset_stats_op {
 596	struct btree_op op;
 597	size_t nodes;
 598	struct bset_stats stats;
 599};
 600
 601static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b)
 602{
 603	struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op);
 604
 605	op->nodes++;
 606	bch_btree_keys_stats(&b->keys, &op->stats);
 607
 608	return MAP_CONTINUE;
 609}
 610
 611static int bch_bset_print_stats(struct cache_set *c, char *buf)
 612{
 613	struct bset_stats_op op;
 614	int ret;
 615
 616	memset(&op, 0, sizeof(op));
 617	bch_btree_op_init(&op.op, -1);
 618
 619	ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats);
 620	if (ret < 0)
 621		return ret;
 622
 623	return snprintf(buf, PAGE_SIZE,
 624			"btree nodes:		%zu\n"
 625			"written sets:		%zu\n"
 626			"unwritten sets:		%zu\n"
 627			"written key bytes:	%zu\n"
 628			"unwritten key bytes:	%zu\n"
 629			"floats:			%zu\n"
 630			"failed:			%zu\n",
 631			op.nodes,
 632			op.stats.sets_written, op.stats.sets_unwritten,
 633			op.stats.bytes_written, op.stats.bytes_unwritten,
 634			op.stats.floats, op.stats.failed);
 635}
 636
 637static unsigned int bch_root_usage(struct cache_set *c)
 638{
 639	unsigned int bytes = 0;
 640	struct bkey *k;
 641	struct btree *b;
 642	struct btree_iter iter;
 643
 644	goto lock_root;
 645
 646	do {
 647		rw_unlock(false, b);
 648lock_root:
 649		b = c->root;
 650		rw_lock(false, b, b->level);
 651	} while (b != c->root);
 652
 653	for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
 654		bytes += bkey_bytes(k);
 655
 656	rw_unlock(false, b);
 657
 658	return (bytes * 100) / btree_bytes(c);
 659}
 660
 661static size_t bch_cache_size(struct cache_set *c)
 662{
 663	size_t ret = 0;
 664	struct btree *b;
 665
 666	mutex_lock(&c->bucket_lock);
 667	list_for_each_entry(b, &c->btree_cache, list)
 668		ret += 1 << (b->keys.page_order + PAGE_SHIFT);
 669
 670	mutex_unlock(&c->bucket_lock);
 671	return ret;
 672}
 673
 674static unsigned int bch_cache_max_chain(struct cache_set *c)
 675{
 676	unsigned int ret = 0;
 677	struct hlist_head *h;
 678
 679	mutex_lock(&c->bucket_lock);
 680
 681	for (h = c->bucket_hash;
 682	     h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
 683	     h++) {
 684		unsigned int i = 0;
 685		struct hlist_node *p;
 686
 687		hlist_for_each(p, h)
 688			i++;
 689
 690		ret = max(ret, i);
 691	}
 692
 693	mutex_unlock(&c->bucket_lock);
 694	return ret;
 695}
 696
 697static unsigned int bch_btree_used(struct cache_set *c)
 698{
 699	return div64_u64(c->gc_stats.key_bytes * 100,
 700			 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
 701}
 702
 703static unsigned int bch_average_key_size(struct cache_set *c)
 704{
 705	return c->gc_stats.nkeys
 706		? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
 707		: 0;
 708}
 709
 710SHOW(__bch_cache_set)
 711{
 712	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
 713
 714	sysfs_print(synchronous,		CACHE_SYNC(&c->sb));
 715	sysfs_print(journal_delay_ms,		c->journal_delay_ms);
 716	sysfs_hprint(bucket_size,		bucket_bytes(c));
 717	sysfs_hprint(block_size,		block_bytes(c));
 718	sysfs_print(tree_depth,			c->root->level);
 719	sysfs_print(root_usage_percent,		bch_root_usage(c));
 720
 721	sysfs_hprint(btree_cache_size,		bch_cache_size(c));
 722	sysfs_print(btree_cache_max_chain,	bch_cache_max_chain(c));
 723	sysfs_print(cache_available_percent,	100 - c->gc_stats.in_use);
 724
 725	sysfs_print_time_stats(&c->btree_gc_time,	btree_gc, sec, ms);
 726	sysfs_print_time_stats(&c->btree_split_time,	btree_split, sec, us);
 727	sysfs_print_time_stats(&c->sort.time,		btree_sort, ms, us);
 728	sysfs_print_time_stats(&c->btree_read_time,	btree_read, ms, us);
 729
 730	sysfs_print(btree_used_percent,	bch_btree_used(c));
 731	sysfs_print(btree_nodes,	c->gc_stats.nodes);
 732	sysfs_hprint(average_key_size,	bch_average_key_size(c));
 733
 734	sysfs_print(cache_read_races,
 735		    atomic_long_read(&c->cache_read_races));
 736
 737	sysfs_print(reclaim,
 738		    atomic_long_read(&c->reclaim));
 739
 740	sysfs_print(reclaimed_journal_buckets,
 741		    atomic_long_read(&c->reclaimed_journal_buckets));
 742
 743	sysfs_print(flush_write,
 744		    atomic_long_read(&c->flush_write));
 745
 746	sysfs_print(writeback_keys_done,
 747		    atomic_long_read(&c->writeback_keys_done));
 748	sysfs_print(writeback_keys_failed,
 749		    atomic_long_read(&c->writeback_keys_failed));
 750
 751	if (attr == &sysfs_errors)
 752		return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
 753					       c->on_error);
 754
 755	/* See count_io_errors for why 88 */
 756	sysfs_print(io_error_halflife,	c->error_decay * 88);
 757	sysfs_print(io_error_limit,	c->error_limit);
 758
 759	sysfs_hprint(congested,
 760		     ((uint64_t) bch_get_congested(c)) << 9);
 761	sysfs_print(congested_read_threshold_us,
 762		    c->congested_read_threshold_us);
 763	sysfs_print(congested_write_threshold_us,
 764		    c->congested_write_threshold_us);
 765
 766	sysfs_print(cutoff_writeback, bch_cutoff_writeback);
 767	sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync);
 768
 769	sysfs_print(active_journal_entries,	fifo_used(&c->journal.pin));
 770	sysfs_printf(verify,			"%i", c->verify);
 771	sysfs_printf(key_merging_disabled,	"%i", c->key_merging_disabled);
 772	sysfs_printf(expensive_debug_checks,
 773		     "%i", c->expensive_debug_checks);
 774	sysfs_printf(gc_always_rewrite,		"%i", c->gc_always_rewrite);
 775	sysfs_printf(btree_shrinker_disabled,	"%i", c->shrinker_disabled);
 776	sysfs_printf(copy_gc_enabled,		"%i", c->copy_gc_enabled);
 777	sysfs_printf(idle_max_writeback_rate,	"%i",
 778		     c->idle_max_writeback_rate_enabled);
 779	sysfs_printf(gc_after_writeback,	"%i", c->gc_after_writeback);
 780	sysfs_printf(io_disable,		"%i",
 781		     test_bit(CACHE_SET_IO_DISABLE, &c->flags));
 782
 783	if (attr == &sysfs_bset_tree_stats)
 784		return bch_bset_print_stats(c, buf);
 785
 786	if (attr == &sysfs_feature_compat)
 787		return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE);
 788	if (attr == &sysfs_feature_ro_compat)
 789		return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE);
 790	if (attr == &sysfs_feature_incompat)
 791		return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE);
 792
 793	return 0;
 794}
 795SHOW_LOCKED(bch_cache_set)
 796
 797STORE(__bch_cache_set)
 798{
 799	struct cache_set *c = container_of(kobj, struct cache_set, kobj);
 800	ssize_t v;
 801
 802	/* no user space access if system is rebooting */
 803	if (bcache_is_reboot)
 804		return -EBUSY;
 805
 806	if (attr == &sysfs_unregister)
 807		bch_cache_set_unregister(c);
 808
 809	if (attr == &sysfs_stop)
 810		bch_cache_set_stop(c);
 811
 812	if (attr == &sysfs_synchronous) {
 813		bool sync = strtoul_or_return(buf);
 814
 815		if (sync != CACHE_SYNC(&c->sb)) {
 816			SET_CACHE_SYNC(&c->sb, sync);
 817			bcache_write_super(c);
 818		}
 819	}
 820
 821	if (attr == &sysfs_flash_vol_create) {
 822		int r;
 823		uint64_t v;
 824
 825		strtoi_h_or_return(buf, v);
 826
 827		r = bch_flash_dev_create(c, v);
 828		if (r)
 829			return r;
 830	}
 831
 832	if (attr == &sysfs_clear_stats) {
 833		atomic_long_set(&c->writeback_keys_done,	0);
 834		atomic_long_set(&c->writeback_keys_failed,	0);
 835
 836		memset(&c->gc_stats, 0, sizeof(struct gc_stat));
 837		bch_cache_accounting_clear(&c->accounting);
 838	}
 839
 840	if (attr == &sysfs_trigger_gc)
 841		force_wake_up_gc(c);
 842
 843	if (attr == &sysfs_prune_cache) {
 844		struct shrink_control sc;
 845
 846		sc.gfp_mask = GFP_KERNEL;
 847		sc.nr_to_scan = strtoul_or_return(buf);
 848		c->shrink.scan_objects(&c->shrink, &sc);
 849	}
 850
 851	sysfs_strtoul_clamp(congested_read_threshold_us,
 852			    c->congested_read_threshold_us,
 853			    0, UINT_MAX);
 854	sysfs_strtoul_clamp(congested_write_threshold_us,
 855			    c->congested_write_threshold_us,
 856			    0, UINT_MAX);
 857
 858	if (attr == &sysfs_errors) {
 859		v = __sysfs_match_string(error_actions, -1, buf);
 860		if (v < 0)
 861			return v;
 862
 863		c->on_error = v;
 864	}
 865
 866	sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
 867
 868	/* See count_io_errors() for why 88 */
 869	if (attr == &sysfs_io_error_halflife) {
 870		unsigned long v = 0;
 871		ssize_t ret;
 872
 873		ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX);
 874		if (!ret) {
 875			c->error_decay = v / 88;
 876			return size;
 877		}
 878		return ret;
 879	}
 880
 881	if (attr == &sysfs_io_disable) {
 882		v = strtoul_or_return(buf);
 883		if (v) {
 884			if (test_and_set_bit(CACHE_SET_IO_DISABLE,
 885					     &c->flags))
 886				pr_warn("CACHE_SET_IO_DISABLE already set\n");
 887		} else {
 888			if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
 889						&c->flags))
 890				pr_warn("CACHE_SET_IO_DISABLE already cleared\n");
 891		}
 892	}
 893
 894	sysfs_strtoul_clamp(journal_delay_ms,
 895			    c->journal_delay_ms,
 896			    0, USHRT_MAX);
 897	sysfs_strtoul_bool(verify,		c->verify);
 898	sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
 899	sysfs_strtoul(expensive_debug_checks,	c->expensive_debug_checks);
 900	sysfs_strtoul_bool(gc_always_rewrite,	c->gc_always_rewrite);
 901	sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
 902	sysfs_strtoul_bool(copy_gc_enabled,	c->copy_gc_enabled);
 903	sysfs_strtoul_bool(idle_max_writeback_rate,
 904			   c->idle_max_writeback_rate_enabled);
 905
 906	/*
 907	 * write gc_after_writeback here may overwrite an already set
 908	 * BCH_DO_AUTO_GC, it doesn't matter because this flag will be
 909	 * set in next chance.
 910	 */
 911	sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1);
 912
 913	return size;
 914}
 915STORE_LOCKED(bch_cache_set)
 916
 917SHOW(bch_cache_set_internal)
 918{
 919	struct cache_set *c = container_of(kobj, struct cache_set, internal);
 920
 921	return bch_cache_set_show(&c->kobj, attr, buf);
 922}
 923
 924STORE(bch_cache_set_internal)
 925{
 926	struct cache_set *c = container_of(kobj, struct cache_set, internal);
 927
 928	/* no user space access if system is rebooting */
 929	if (bcache_is_reboot)
 930		return -EBUSY;
 931
 932	return bch_cache_set_store(&c->kobj, attr, buf, size);
 933}
 934
 935static void bch_cache_set_internal_release(struct kobject *k)
 936{
 937}
 938
 939static struct attribute *bch_cache_set_files[] = {
 940	&sysfs_unregister,
 941	&sysfs_stop,
 942	&sysfs_synchronous,
 943	&sysfs_journal_delay_ms,
 944	&sysfs_flash_vol_create,
 945
 946	&sysfs_bucket_size,
 947	&sysfs_block_size,
 948	&sysfs_tree_depth,
 949	&sysfs_root_usage_percent,
 950	&sysfs_btree_cache_size,
 951	&sysfs_cache_available_percent,
 952
 953	&sysfs_average_key_size,
 954
 955	&sysfs_errors,
 956	&sysfs_io_error_limit,
 957	&sysfs_io_error_halflife,
 958	&sysfs_congested,
 959	&sysfs_congested_read_threshold_us,
 960	&sysfs_congested_write_threshold_us,
 961	&sysfs_clear_stats,
 962	NULL
 963};
 964KTYPE(bch_cache_set);
 965
 966static struct attribute *bch_cache_set_internal_files[] = {
 967	&sysfs_active_journal_entries,
 968
 969	sysfs_time_stats_attribute_list(btree_gc, sec, ms)
 970	sysfs_time_stats_attribute_list(btree_split, sec, us)
 971	sysfs_time_stats_attribute_list(btree_sort, ms, us)
 972	sysfs_time_stats_attribute_list(btree_read, ms, us)
 973
 974	&sysfs_btree_nodes,
 975	&sysfs_btree_used_percent,
 976	&sysfs_btree_cache_max_chain,
 977
 978	&sysfs_bset_tree_stats,
 979	&sysfs_cache_read_races,
 980	&sysfs_reclaim,
 981	&sysfs_reclaimed_journal_buckets,
 982	&sysfs_flush_write,
 983	&sysfs_writeback_keys_done,
 984	&sysfs_writeback_keys_failed,
 985
 986	&sysfs_trigger_gc,
 987	&sysfs_prune_cache,
 988#ifdef CONFIG_BCACHE_DEBUG
 989	&sysfs_verify,
 990	&sysfs_key_merging_disabled,
 991	&sysfs_expensive_debug_checks,
 992#endif
 993	&sysfs_gc_always_rewrite,
 994	&sysfs_btree_shrinker_disabled,
 995	&sysfs_copy_gc_enabled,
 996	&sysfs_idle_max_writeback_rate,
 997	&sysfs_gc_after_writeback,
 998	&sysfs_io_disable,
 999	&sysfs_cutoff_writeback,
1000	&sysfs_cutoff_writeback_sync,
1001	&sysfs_feature_compat,
1002	&sysfs_feature_ro_compat,
1003	&sysfs_feature_incompat,
1004	NULL
1005};
1006KTYPE(bch_cache_set_internal);
1007
1008static int __bch_cache_cmp(const void *l, const void *r)
1009{
1010	cond_resched();
1011	return *((uint16_t *)r) - *((uint16_t *)l);
1012}
1013
1014SHOW(__bch_cache)
1015{
1016	struct cache *ca = container_of(kobj, struct cache, kobj);
1017
1018	sysfs_hprint(bucket_size,	bucket_bytes(ca));
1019	sysfs_hprint(block_size,	block_bytes(ca));
1020	sysfs_print(nbuckets,		ca->sb.nbuckets);
1021	sysfs_print(discard,		ca->discard);
1022	sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
1023	sysfs_hprint(btree_written,
1024		     atomic_long_read(&ca->btree_sectors_written) << 9);
1025	sysfs_hprint(metadata_written,
1026		     (atomic_long_read(&ca->meta_sectors_written) +
1027		      atomic_long_read(&ca->btree_sectors_written)) << 9);
1028
1029	sysfs_print(io_errors,
1030		    atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
1031
1032	if (attr == &sysfs_cache_replacement_policy)
1033		return bch_snprint_string_list(buf, PAGE_SIZE,
1034					       cache_replacement_policies,
1035					       CACHE_REPLACEMENT(&ca->sb));
1036
1037	if (attr == &sysfs_priority_stats) {
1038		struct bucket *b;
1039		size_t n = ca->sb.nbuckets, i;
1040		size_t unused = 0, available = 0, dirty = 0, meta = 0;
1041		uint64_t sum = 0;
1042		/* Compute 31 quantiles */
1043		uint16_t q[31], *p, *cached;
1044		ssize_t ret;
1045
1046		cached = p = vmalloc(array_size(sizeof(uint16_t),
1047						ca->sb.nbuckets));
1048		if (!p)
1049			return -ENOMEM;
1050
1051		mutex_lock(&ca->set->bucket_lock);
1052		for_each_bucket(b, ca) {
1053			if (!GC_SECTORS_USED(b))
1054				unused++;
1055			if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
1056				available++;
1057			if (GC_MARK(b) == GC_MARK_DIRTY)
1058				dirty++;
1059			if (GC_MARK(b) == GC_MARK_METADATA)
1060				meta++;
1061		}
1062
1063		for (i = ca->sb.first_bucket; i < n; i++)
1064			p[i] = ca->buckets[i].prio;
1065		mutex_unlock(&ca->set->bucket_lock);
1066
1067		sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
1068
1069		while (n &&
1070		       !cached[n - 1])
1071			--n;
1072
1073		while (cached < p + n &&
1074		       *cached == BTREE_PRIO)
1075			cached++, n--;
1076
1077		for (i = 0; i < n; i++)
1078			sum += INITIAL_PRIO - cached[i];
1079
1080		if (n)
1081			do_div(sum, n);
1082
1083		for (i = 0; i < ARRAY_SIZE(q); i++)
1084			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
1085				(ARRAY_SIZE(q) + 1)];
1086
1087		vfree(p);
1088
1089		ret = scnprintf(buf, PAGE_SIZE,
1090				"Unused:		%zu%%\n"
1091				"Clean:		%zu%%\n"
1092				"Dirty:		%zu%%\n"
1093				"Metadata:	%zu%%\n"
1094				"Average:	%llu\n"
1095				"Sectors per Q:	%zu\n"
1096				"Quantiles:	[",
1097				unused * 100 / (size_t) ca->sb.nbuckets,
1098				available * 100 / (size_t) ca->sb.nbuckets,
1099				dirty * 100 / (size_t) ca->sb.nbuckets,
1100				meta * 100 / (size_t) ca->sb.nbuckets, sum,
1101				n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
1102
1103		for (i = 0; i < ARRAY_SIZE(q); i++)
1104			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
1105					 "%u ", q[i]);
1106		ret--;
1107
1108		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
1109
1110		return ret;
1111	}
1112
1113	return 0;
1114}
1115SHOW_LOCKED(bch_cache)
1116
1117STORE(__bch_cache)
1118{
1119	struct cache *ca = container_of(kobj, struct cache, kobj);
1120	ssize_t v;
1121
1122	/* no user space access if system is rebooting */
1123	if (bcache_is_reboot)
1124		return -EBUSY;
1125
1126	if (attr == &sysfs_discard) {
1127		bool v = strtoul_or_return(buf);
1128
1129		if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1130			ca->discard = v;
1131
1132		if (v != CACHE_DISCARD(&ca->sb)) {
1133			SET_CACHE_DISCARD(&ca->sb, v);
1134			bcache_write_super(ca->set);
1135		}
1136	}
1137
1138	if (attr == &sysfs_cache_replacement_policy) {
1139		v = __sysfs_match_string(cache_replacement_policies, -1, buf);
1140		if (v < 0)
1141			return v;
1142
1143		if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
1144			mutex_lock(&ca->set->bucket_lock);
1145			SET_CACHE_REPLACEMENT(&ca->sb, v);
1146			mutex_unlock(&ca->set->bucket_lock);
1147
1148			bcache_write_super(ca->set);
1149		}
1150	}
1151
1152	if (attr == &sysfs_clear_stats) {
1153		atomic_long_set(&ca->sectors_written, 0);
1154		atomic_long_set(&ca->btree_sectors_written, 0);
1155		atomic_long_set(&ca->meta_sectors_written, 0);
1156		atomic_set(&ca->io_count, 0);
1157		atomic_set(&ca->io_errors, 0);
1158	}
1159
1160	return size;
1161}
1162STORE_LOCKED(bch_cache)
1163
1164static struct attribute *bch_cache_files[] = {
1165	&sysfs_bucket_size,
1166	&sysfs_block_size,
1167	&sysfs_nbuckets,
1168	&sysfs_priority_stats,
1169	&sysfs_discard,
1170	&sysfs_written,
1171	&sysfs_btree_written,
1172	&sysfs_metadata_written,
1173	&sysfs_io_errors,
1174	&sysfs_clear_stats,
1175	&sysfs_cache_replacement_policy,
1176	NULL
1177};
1178KTYPE(bch_cache);