2 * bcache sysfs interfaces
4 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
5 * Copyright 2012 Google, Inc.
12 #include "writeback.h"
14 #include <linux/blkdev.h>
15 #include <linux/sort.h>
17 static const char * const cache_replacement_policies[] = {
24 static const char * const error_actions[] = {
30 write_attribute(attach);
31 write_attribute(detach);
32 write_attribute(unregister);
33 write_attribute(stop);
34 write_attribute(clear_stats);
35 write_attribute(trigger_gc);
36 write_attribute(prune_cache);
37 write_attribute(flash_vol_create);
39 read_attribute(bucket_size);
40 read_attribute(block_size);
41 read_attribute(nbuckets);
42 read_attribute(tree_depth);
43 read_attribute(root_usage_percent);
44 read_attribute(priority_stats);
45 read_attribute(btree_cache_size);
46 read_attribute(btree_cache_max_chain);
47 read_attribute(cache_available_percent);
48 read_attribute(written);
49 read_attribute(btree_written);
50 read_attribute(metadata_written);
51 read_attribute(active_journal_entries);
53 sysfs_time_stats_attribute(btree_gc, sec, ms);
54 sysfs_time_stats_attribute(btree_split, sec, us);
55 sysfs_time_stats_attribute(btree_sort, ms, us);
56 sysfs_time_stats_attribute(btree_read, ms, us);
57 sysfs_time_stats_attribute(try_harder, ms, us);
59 read_attribute(btree_nodes);
60 read_attribute(btree_used_percent);
61 read_attribute(average_key_size);
62 read_attribute(dirty_data);
63 read_attribute(bset_tree_stats);
65 read_attribute(state);
66 read_attribute(cache_read_races);
67 read_attribute(writeback_keys_done);
68 read_attribute(writeback_keys_failed);
69 read_attribute(io_errors);
70 read_attribute(congested);
71 rw_attribute(congested_read_threshold_us);
72 rw_attribute(congested_write_threshold_us);
74 rw_attribute(sequential_cutoff);
75 rw_attribute(sequential_merge);
76 rw_attribute(data_csum);
77 rw_attribute(cache_mode);
78 rw_attribute(writeback_metadata);
79 rw_attribute(writeback_running);
80 rw_attribute(writeback_percent);
81 rw_attribute(writeback_delay);
82 rw_attribute(writeback_rate);
84 rw_attribute(writeback_rate_update_seconds);
85 rw_attribute(writeback_rate_d_term);
86 rw_attribute(writeback_rate_p_term_inverse);
87 rw_attribute(writeback_rate_d_smooth);
88 read_attribute(writeback_rate_debug);
90 read_attribute(stripe_size);
91 read_attribute(partial_stripes_expensive);
93 rw_attribute(synchronous);
94 rw_attribute(journal_delay_ms);
95 rw_attribute(discard);
96 rw_attribute(running);
98 rw_attribute(readahead);
100 rw_attribute(io_error_limit);
101 rw_attribute(io_error_halflife);
102 rw_attribute(verify);
103 rw_attribute(key_merging_disabled);
104 rw_attribute(gc_always_rewrite);
105 rw_attribute(expensive_debug_checks);
106 rw_attribute(freelist_percent);
107 rw_attribute(cache_replacement_policy);
108 rw_attribute(btree_shrinker_disabled);
109 rw_attribute(copy_gc_enabled);
112 SHOW(__bch_cached_dev)
114 struct cached_dev *dc = container_of(kobj, struct cached_dev,
116 const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
118 #define var(stat) (dc->stat)
120 if (attr == &sysfs_cache_mode)
121 return bch_snprint_string_list(buf, PAGE_SIZE,
123 BDEV_CACHE_MODE(&dc->sb));
125 sysfs_printf(data_csum, "%i", dc->disk.data_csum);
126 var_printf(verify, "%i");
127 var_printf(writeback_metadata, "%i");
128 var_printf(writeback_running, "%i");
129 var_print(writeback_delay);
130 var_print(writeback_percent);
131 sysfs_print(writeback_rate, dc->writeback_rate.rate);
133 var_print(writeback_rate_update_seconds);
134 var_print(writeback_rate_d_term);
135 var_print(writeback_rate_p_term_inverse);
136 var_print(writeback_rate_d_smooth);
138 if (attr == &sysfs_writeback_rate_debug) {
143 bcache_dev_sectors_dirty(&dc->disk) << 9);
144 bch_hprint(derivative, dc->writeback_rate_derivative << 9);
145 bch_hprint(target, dc->writeback_rate_target << 9);
153 dc->writeback_rate.rate,
154 dc->writeback_rate_change,
155 dirty, derivative, target);
158 sysfs_hprint(dirty_data,
159 bcache_dev_sectors_dirty(&dc->disk) << 9);
161 sysfs_hprint(stripe_size, dc->disk.stripe_size << 9);
162 var_printf(partial_stripes_expensive, "%u");
164 var_printf(sequential_merge, "%i");
165 var_hprint(sequential_cutoff);
166 var_hprint(readahead);
168 sysfs_print(running, atomic_read(&dc->running));
169 sysfs_print(state, states[BDEV_STATE(&dc->sb)]);
171 if (attr == &sysfs_label) {
172 memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
173 buf[SB_LABEL_SIZE + 1] = '\0';
181 SHOW_LOCKED(bch_cached_dev)
185 struct cached_dev *dc = container_of(kobj, struct cached_dev,
189 struct kobj_uevent_env *env;
191 #define d_strtoul(var) sysfs_strtoul(var, dc->var)
192 #define d_strtoi_h(var) sysfs_hatoi(var, dc->var)
194 sysfs_strtoul(data_csum, dc->disk.data_csum);
196 d_strtoul(writeback_metadata);
197 d_strtoul(writeback_running);
198 d_strtoul(writeback_delay);
199 sysfs_strtoul_clamp(writeback_rate,
200 dc->writeback_rate.rate, 1, 1000000);
201 sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40);
203 d_strtoul(writeback_rate_update_seconds);
204 d_strtoul(writeback_rate_d_term);
205 d_strtoul(writeback_rate_p_term_inverse);
206 sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
207 dc->writeback_rate_p_term_inverse, 1, INT_MAX);
208 d_strtoul(writeback_rate_d_smooth);
210 d_strtoul(sequential_merge);
211 d_strtoi_h(sequential_cutoff);
212 d_strtoi_h(readahead);
214 if (attr == &sysfs_clear_stats)
215 bch_cache_accounting_clear(&dc->accounting);
217 if (attr == &sysfs_running &&
218 strtoul_or_return(buf))
219 bch_cached_dev_run(dc);
221 if (attr == &sysfs_cache_mode) {
222 ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1);
227 if ((unsigned) v != BDEV_CACHE_MODE(&dc->sb)) {
228 SET_BDEV_CACHE_MODE(&dc->sb, v);
229 bch_write_bdev_super(dc, NULL);
233 if (attr == &sysfs_label) {
234 if (size > SB_LABEL_SIZE)
236 memcpy(dc->sb.label, buf, size);
237 if (size < SB_LABEL_SIZE)
238 dc->sb.label[size] = '\0';
239 if (size && dc->sb.label[size - 1] == '\n')
240 dc->sb.label[size - 1] = '\0';
241 bch_write_bdev_super(dc, NULL);
243 memcpy(dc->disk.c->uuids[dc->disk.id].label,
245 bch_uuid_write(dc->disk.c);
247 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
250 add_uevent_var(env, "DRIVER=bcache");
251 add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
252 add_uevent_var(env, "CACHED_LABEL=%s", buf);
254 &disk_to_dev(dc->disk.disk)->kobj, KOBJ_CHANGE, env->envp);
258 if (attr == &sysfs_attach) {
259 if (bch_parse_uuid(buf, dc->sb.set_uuid) < 16)
262 list_for_each_entry(c, &bch_cache_sets, list) {
263 v = bch_cached_dev_attach(dc, c);
268 pr_err("Can't attach %s: cache set not found", buf);
272 if (attr == &sysfs_detach && dc->disk.c)
273 bch_cached_dev_detach(dc);
275 if (attr == &sysfs_stop)
276 bcache_device_stop(&dc->disk);
281 STORE(bch_cached_dev)
283 struct cached_dev *dc = container_of(kobj, struct cached_dev,
286 mutex_lock(&bch_register_lock);
287 size = __cached_dev_store(kobj, attr, buf, size);
289 if (attr == &sysfs_writeback_running)
290 bch_writeback_queue(dc);
292 if (attr == &sysfs_writeback_percent)
293 schedule_delayed_work(&dc->writeback_rate_update,
294 dc->writeback_rate_update_seconds * HZ);
296 mutex_unlock(&bch_register_lock);
300 static struct attribute *bch_cached_dev_files[] = {
308 &sysfs_writeback_metadata,
309 &sysfs_writeback_running,
310 &sysfs_writeback_delay,
311 &sysfs_writeback_percent,
312 &sysfs_writeback_rate,
313 &sysfs_writeback_rate_update_seconds,
314 &sysfs_writeback_rate_d_term,
315 &sysfs_writeback_rate_p_term_inverse,
316 &sysfs_writeback_rate_d_smooth,
317 &sysfs_writeback_rate_debug,
320 &sysfs_partial_stripes_expensive,
321 &sysfs_sequential_cutoff,
322 &sysfs_sequential_merge,
328 #ifdef CONFIG_BCACHE_DEBUG
333 KTYPE(bch_cached_dev);
337 struct bcache_device *d = container_of(kobj, struct bcache_device,
339 struct uuid_entry *u = &d->c->uuids[d->id];
341 sysfs_printf(data_csum, "%i", d->data_csum);
342 sysfs_hprint(size, u->sectors << 9);
344 if (attr == &sysfs_label) {
345 memcpy(buf, u->label, SB_LABEL_SIZE);
346 buf[SB_LABEL_SIZE + 1] = '\0';
354 STORE(__bch_flash_dev)
356 struct bcache_device *d = container_of(kobj, struct bcache_device,
358 struct uuid_entry *u = &d->c->uuids[d->id];
360 sysfs_strtoul(data_csum, d->data_csum);
362 if (attr == &sysfs_size) {
364 strtoi_h_or_return(buf, v);
367 bch_uuid_write(d->c);
368 set_capacity(d->disk, u->sectors);
371 if (attr == &sysfs_label) {
372 memcpy(u->label, buf, SB_LABEL_SIZE);
373 bch_uuid_write(d->c);
376 if (attr == &sysfs_unregister) {
377 atomic_set(&d->detaching, 1);
378 bcache_device_stop(d);
383 STORE_LOCKED(bch_flash_dev)
385 static struct attribute *bch_flash_dev_files[] = {
394 KTYPE(bch_flash_dev);
396 SHOW(__bch_cache_set)
398 unsigned root_usage(struct cache_set *c)
403 struct btree_iter iter;
411 rw_lock(false, b, b->level);
412 } while (b != c->root);
414 for_each_key_filter(b, k, &iter, bch_ptr_bad)
415 bytes += bkey_bytes(k);
419 return (bytes * 100) / btree_bytes(c);
422 size_t cache_size(struct cache_set *c)
427 mutex_lock(&c->bucket_lock);
428 list_for_each_entry(b, &c->btree_cache, list)
429 ret += 1 << (b->page_order + PAGE_SHIFT);
431 mutex_unlock(&c->bucket_lock);
435 unsigned cache_max_chain(struct cache_set *c)
438 struct hlist_head *h;
440 mutex_lock(&c->bucket_lock);
442 for (h = c->bucket_hash;
443 h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
446 struct hlist_node *p;
454 mutex_unlock(&c->bucket_lock);
458 unsigned btree_used(struct cache_set *c)
460 return div64_u64(c->gc_stats.key_bytes * 100,
461 (c->gc_stats.nodes ?: 1) * btree_bytes(c));
464 unsigned average_key_size(struct cache_set *c)
466 return c->gc_stats.nkeys
467 ? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
471 struct cache_set *c = container_of(kobj, struct cache_set, kobj);
473 sysfs_print(synchronous, CACHE_SYNC(&c->sb));
474 sysfs_print(journal_delay_ms, c->journal_delay_ms);
475 sysfs_hprint(bucket_size, bucket_bytes(c));
476 sysfs_hprint(block_size, block_bytes(c));
477 sysfs_print(tree_depth, c->root->level);
478 sysfs_print(root_usage_percent, root_usage(c));
480 sysfs_hprint(btree_cache_size, cache_size(c));
481 sysfs_print(btree_cache_max_chain, cache_max_chain(c));
482 sysfs_print(cache_available_percent, 100 - c->gc_stats.in_use);
484 sysfs_print_time_stats(&c->btree_gc_time, btree_gc, sec, ms);
485 sysfs_print_time_stats(&c->btree_split_time, btree_split, sec, us);
486 sysfs_print_time_stats(&c->sort_time, btree_sort, ms, us);
487 sysfs_print_time_stats(&c->btree_read_time, btree_read, ms, us);
488 sysfs_print_time_stats(&c->try_harder_time, try_harder, ms, us);
490 sysfs_print(btree_used_percent, btree_used(c));
491 sysfs_print(btree_nodes, c->gc_stats.nodes);
492 sysfs_hprint(average_key_size, average_key_size(c));
494 sysfs_print(cache_read_races,
495 atomic_long_read(&c->cache_read_races));
497 sysfs_print(writeback_keys_done,
498 atomic_long_read(&c->writeback_keys_done));
499 sysfs_print(writeback_keys_failed,
500 atomic_long_read(&c->writeback_keys_failed));
502 if (attr == &sysfs_errors)
503 return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
506 /* See count_io_errors for why 88 */
507 sysfs_print(io_error_halflife, c->error_decay * 88);
508 sysfs_print(io_error_limit, c->error_limit >> IO_ERROR_SHIFT);
510 sysfs_hprint(congested,
511 ((uint64_t) bch_get_congested(c)) << 9);
512 sysfs_print(congested_read_threshold_us,
513 c->congested_read_threshold_us);
514 sysfs_print(congested_write_threshold_us,
515 c->congested_write_threshold_us);
517 sysfs_print(active_journal_entries, fifo_used(&c->journal.pin));
518 sysfs_printf(verify, "%i", c->verify);
519 sysfs_printf(key_merging_disabled, "%i", c->key_merging_disabled);
520 sysfs_printf(expensive_debug_checks,
521 "%i", c->expensive_debug_checks);
522 sysfs_printf(gc_always_rewrite, "%i", c->gc_always_rewrite);
523 sysfs_printf(btree_shrinker_disabled, "%i", c->shrinker_disabled);
524 sysfs_printf(copy_gc_enabled, "%i", c->copy_gc_enabled);
526 if (attr == &sysfs_bset_tree_stats)
527 return bch_bset_print_stats(c, buf);
531 SHOW_LOCKED(bch_cache_set)
533 STORE(__bch_cache_set)
535 struct cache_set *c = container_of(kobj, struct cache_set, kobj);
537 if (attr == &sysfs_unregister)
538 bch_cache_set_unregister(c);
540 if (attr == &sysfs_stop)
541 bch_cache_set_stop(c);
543 if (attr == &sysfs_synchronous) {
544 bool sync = strtoul_or_return(buf);
546 if (sync != CACHE_SYNC(&c->sb)) {
547 SET_CACHE_SYNC(&c->sb, sync);
548 bcache_write_super(c);
552 if (attr == &sysfs_flash_vol_create) {
555 strtoi_h_or_return(buf, v);
557 r = bch_flash_dev_create(c, v);
562 if (attr == &sysfs_clear_stats) {
563 atomic_long_set(&c->writeback_keys_done, 0);
564 atomic_long_set(&c->writeback_keys_failed, 0);
566 memset(&c->gc_stats, 0, sizeof(struct gc_stat));
567 bch_cache_accounting_clear(&c->accounting);
570 if (attr == &sysfs_trigger_gc)
573 if (attr == &sysfs_prune_cache) {
574 struct shrink_control sc;
575 sc.gfp_mask = GFP_KERNEL;
576 sc.nr_to_scan = strtoul_or_return(buf);
577 c->shrink.scan_objects(&c->shrink, &sc);
580 sysfs_strtoul(congested_read_threshold_us,
581 c->congested_read_threshold_us);
582 sysfs_strtoul(congested_write_threshold_us,
583 c->congested_write_threshold_us);
585 if (attr == &sysfs_errors) {
586 ssize_t v = bch_read_string_list(buf, error_actions);
594 if (attr == &sysfs_io_error_limit)
595 c->error_limit = strtoul_or_return(buf) << IO_ERROR_SHIFT;
597 /* See count_io_errors() for why 88 */
598 if (attr == &sysfs_io_error_halflife)
599 c->error_decay = strtoul_or_return(buf) / 88;
601 sysfs_strtoul(journal_delay_ms, c->journal_delay_ms);
602 sysfs_strtoul(verify, c->verify);
603 sysfs_strtoul(key_merging_disabled, c->key_merging_disabled);
604 sysfs_strtoul(expensive_debug_checks, c->expensive_debug_checks);
605 sysfs_strtoul(gc_always_rewrite, c->gc_always_rewrite);
606 sysfs_strtoul(btree_shrinker_disabled, c->shrinker_disabled);
607 sysfs_strtoul(copy_gc_enabled, c->copy_gc_enabled);
611 STORE_LOCKED(bch_cache_set)
613 SHOW(bch_cache_set_internal)
615 struct cache_set *c = container_of(kobj, struct cache_set, internal);
616 return bch_cache_set_show(&c->kobj, attr, buf);
619 STORE(bch_cache_set_internal)
621 struct cache_set *c = container_of(kobj, struct cache_set, internal);
622 return bch_cache_set_store(&c->kobj, attr, buf, size);
625 static void bch_cache_set_internal_release(struct kobject *k)
629 static struct attribute *bch_cache_set_files[] = {
633 &sysfs_journal_delay_ms,
634 &sysfs_flash_vol_create,
639 &sysfs_root_usage_percent,
640 &sysfs_btree_cache_size,
641 &sysfs_cache_available_percent,
643 &sysfs_average_key_size,
646 &sysfs_io_error_limit,
647 &sysfs_io_error_halflife,
649 &sysfs_congested_read_threshold_us,
650 &sysfs_congested_write_threshold_us,
654 KTYPE(bch_cache_set);
656 static struct attribute *bch_cache_set_internal_files[] = {
657 &sysfs_active_journal_entries,
659 sysfs_time_stats_attribute_list(btree_gc, sec, ms)
660 sysfs_time_stats_attribute_list(btree_split, sec, us)
661 sysfs_time_stats_attribute_list(btree_sort, ms, us)
662 sysfs_time_stats_attribute_list(btree_read, ms, us)
663 sysfs_time_stats_attribute_list(try_harder, ms, us)
666 &sysfs_btree_used_percent,
667 &sysfs_btree_cache_max_chain,
669 &sysfs_bset_tree_stats,
670 &sysfs_cache_read_races,
671 &sysfs_writeback_keys_done,
672 &sysfs_writeback_keys_failed,
676 #ifdef CONFIG_BCACHE_DEBUG
678 &sysfs_key_merging_disabled,
679 &sysfs_expensive_debug_checks,
681 &sysfs_gc_always_rewrite,
682 &sysfs_btree_shrinker_disabled,
683 &sysfs_copy_gc_enabled,
686 KTYPE(bch_cache_set_internal);
690 struct cache *ca = container_of(kobj, struct cache, kobj);
692 sysfs_hprint(bucket_size, bucket_bytes(ca));
693 sysfs_hprint(block_size, block_bytes(ca));
694 sysfs_print(nbuckets, ca->sb.nbuckets);
695 sysfs_print(discard, ca->discard);
696 sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
697 sysfs_hprint(btree_written,
698 atomic_long_read(&ca->btree_sectors_written) << 9);
699 sysfs_hprint(metadata_written,
700 (atomic_long_read(&ca->meta_sectors_written) +
701 atomic_long_read(&ca->btree_sectors_written)) << 9);
703 sysfs_print(io_errors,
704 atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
706 sysfs_print(freelist_percent, ca->free.size * 100 /
707 ((size_t) ca->sb.nbuckets));
709 if (attr == &sysfs_cache_replacement_policy)
710 return bch_snprint_string_list(buf, PAGE_SIZE,
711 cache_replacement_policies,
712 CACHE_REPLACEMENT(&ca->sb));
714 if (attr == &sysfs_priority_stats) {
715 int cmp(const void *l, const void *r)
716 { return *((uint16_t *) r) - *((uint16_t *) l); }
718 size_t n = ca->sb.nbuckets, i, unused, btree;
720 /* Compute 31 quantiles */
721 uint16_t q[31], *p, *cached;
724 cached = p = vmalloc(ca->sb.nbuckets * sizeof(uint16_t));
728 mutex_lock(&ca->set->bucket_lock);
729 for (i = ca->sb.first_bucket; i < n; i++)
730 p[i] = ca->buckets[i].prio;
731 mutex_unlock(&ca->set->bucket_lock);
733 sort(p, n, sizeof(uint16_t), cmp, NULL);
739 unused = ca->sb.nbuckets - n;
741 while (cached < p + n &&
742 *cached == BTREE_PRIO)
748 for (i = 0; i < n; i++)
749 sum += INITIAL_PRIO - cached[i];
754 for (i = 0; i < ARRAY_SIZE(q); i++)
755 q[i] = INITIAL_PRIO - cached[n * (i + 1) /
756 (ARRAY_SIZE(q) + 1)];
760 ret = scnprintf(buf, PAGE_SIZE,
764 "Sectors per Q: %zu\n"
766 unused * 100 / (size_t) ca->sb.nbuckets,
767 btree * 100 / (size_t) ca->sb.nbuckets, sum,
768 n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
770 for (i = 0; i < ARRAY_SIZE(q); i++)
771 ret += scnprintf(buf + ret, PAGE_SIZE - ret,
775 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
782 SHOW_LOCKED(bch_cache)
786 struct cache *ca = container_of(kobj, struct cache, kobj);
788 if (attr == &sysfs_discard) {
789 bool v = strtoul_or_return(buf);
791 if (blk_queue_discard(bdev_get_queue(ca->bdev)))
794 if (v != CACHE_DISCARD(&ca->sb)) {
795 SET_CACHE_DISCARD(&ca->sb, v);
796 bcache_write_super(ca->set);
800 if (attr == &sysfs_cache_replacement_policy) {
801 ssize_t v = bch_read_string_list(buf, cache_replacement_policies);
806 if ((unsigned) v != CACHE_REPLACEMENT(&ca->sb)) {
807 mutex_lock(&ca->set->bucket_lock);
808 SET_CACHE_REPLACEMENT(&ca->sb, v);
809 mutex_unlock(&ca->set->bucket_lock);
811 bcache_write_super(ca->set);
815 if (attr == &sysfs_freelist_percent) {
816 DECLARE_FIFO(long, free);
818 size_t p = strtoul_or_return(buf);
821 ((size_t) ca->sb.nbuckets * p) / 100,
822 roundup_pow_of_two(ca->sb.nbuckets) >> 9,
823 ca->sb.nbuckets / 2);
825 if (!init_fifo_exact(&free, p, GFP_KERNEL))
828 mutex_lock(&ca->set->bucket_lock);
830 fifo_move(&free, &ca->free);
831 fifo_swap(&free, &ca->free);
833 mutex_unlock(&ca->set->bucket_lock);
835 while (fifo_pop(&free, i))
836 atomic_dec(&ca->buckets[i].pin);
841 if (attr == &sysfs_clear_stats) {
842 atomic_long_set(&ca->sectors_written, 0);
843 atomic_long_set(&ca->btree_sectors_written, 0);
844 atomic_long_set(&ca->meta_sectors_written, 0);
845 atomic_set(&ca->io_count, 0);
846 atomic_set(&ca->io_errors, 0);
851 STORE_LOCKED(bch_cache)
853 static struct attribute *bch_cache_files[] = {
857 &sysfs_priority_stats,
860 &sysfs_btree_written,
861 &sysfs_metadata_written,
864 &sysfs_freelist_percent,
865 &sysfs_cache_replacement_policy,