/* * bcache sysfs interfaces * * Copyright 2010, 2011 Kent Overstreet * Copyright 2012 Google, Inc. */ #include "bcache.h" #include "sysfs.h" #include "btree.h" #include "request.h" #include "writeback.h" #include #include static const char * const cache_replacement_policies[] = { "lru", "fifo", "random", NULL }; static const char * const error_actions[] = { "unregister", "panic", NULL }; write_attribute(attach); write_attribute(detach); write_attribute(unregister); write_attribute(stop); write_attribute(clear_stats); write_attribute(trigger_gc); write_attribute(prune_cache); write_attribute(flash_vol_create); read_attribute(bucket_size); read_attribute(block_size); read_attribute(nbuckets); read_attribute(tree_depth); read_attribute(root_usage_percent); read_attribute(priority_stats); read_attribute(btree_cache_size); read_attribute(btree_cache_max_chain); read_attribute(cache_available_percent); read_attribute(written); read_attribute(btree_written); read_attribute(metadata_written); read_attribute(active_journal_entries); sysfs_time_stats_attribute(btree_gc, sec, ms); sysfs_time_stats_attribute(btree_split, sec, us); sysfs_time_stats_attribute(btree_sort, ms, us); sysfs_time_stats_attribute(btree_read, ms, us); sysfs_time_stats_attribute(try_harder, ms, us); read_attribute(btree_nodes); read_attribute(btree_used_percent); read_attribute(average_key_size); read_attribute(dirty_data); read_attribute(bset_tree_stats); read_attribute(state); read_attribute(cache_read_races); read_attribute(writeback_keys_done); read_attribute(writeback_keys_failed); read_attribute(io_errors); read_attribute(congested); rw_attribute(congested_read_threshold_us); rw_attribute(congested_write_threshold_us); rw_attribute(sequential_cutoff); rw_attribute(sequential_merge); rw_attribute(data_csum); rw_attribute(cache_mode); rw_attribute(writeback_metadata); rw_attribute(writeback_running); rw_attribute(writeback_percent); rw_attribute(writeback_delay); rw_attribute(writeback_rate); rw_attribute(writeback_rate_update_seconds); rw_attribute(writeback_rate_d_term); rw_attribute(writeback_rate_p_term_inverse); rw_attribute(writeback_rate_d_smooth); read_attribute(writeback_rate_debug); read_attribute(stripe_size); read_attribute(partial_stripes_expensive); rw_attribute(synchronous); rw_attribute(journal_delay_ms); rw_attribute(discard); rw_attribute(running); rw_attribute(label); rw_attribute(readahead); rw_attribute(errors); rw_attribute(io_error_limit); rw_attribute(io_error_halflife); rw_attribute(verify); rw_attribute(key_merging_disabled); rw_attribute(gc_always_rewrite); rw_attribute(freelist_percent); rw_attribute(cache_replacement_policy); rw_attribute(btree_shrinker_disabled); rw_attribute(copy_gc_enabled); rw_attribute(size); SHOW(__bch_cached_dev) { struct cached_dev *dc = container_of(kobj, struct cached_dev, disk.kobj); const char *states[] = { "no cache", "clean", "dirty", "inconsistent" }; #define var(stat) (dc->stat) if (attr == &sysfs_cache_mode) return bch_snprint_string_list(buf, PAGE_SIZE, bch_cache_modes + 1, BDEV_CACHE_MODE(&dc->sb)); sysfs_printf(data_csum, "%i", dc->disk.data_csum); var_printf(verify, "%i"); var_printf(writeback_metadata, "%i"); var_printf(writeback_running, "%i"); var_print(writeback_delay); var_print(writeback_percent); sysfs_print(writeback_rate, dc->writeback_rate.rate); var_print(writeback_rate_update_seconds); var_print(writeback_rate_d_term); var_print(writeback_rate_p_term_inverse); var_print(writeback_rate_d_smooth); if (attr == &sysfs_writeback_rate_debug) { char dirty[20]; char derivative[20]; char target[20]; bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9); bch_hprint(derivative, dc->writeback_rate_derivative << 9); bch_hprint(target, dc->writeback_rate_target << 9); return sprintf(buf, "rate:\t\t%u\n" "change:\t\t%i\n" "dirty:\t\t%s\n" "derivative:\t%s\n" "target:\t\t%s\n", dc->writeback_rate.rate, dc->writeback_rate_change, dirty, derivative, target); } sysfs_hprint(dirty_data, bcache_dev_sectors_dirty(&dc->disk) << 9); sysfs_hprint(stripe_size, (1 << dc->disk.stripe_size_bits) << 9); var_printf(partial_stripes_expensive, "%u"); var_printf(sequential_merge, "%i"); var_hprint(sequential_cutoff); var_hprint(readahead); sysfs_print(running, atomic_read(&dc->running)); sysfs_print(state, states[BDEV_STATE(&dc->sb)]); if (attr == &sysfs_label) { memcpy(buf, dc->sb.label, SB_LABEL_SIZE); buf[SB_LABEL_SIZE + 1] = '\0'; strcat(buf, "\n"); return strlen(buf); } #undef var return 0; } SHOW_LOCKED(bch_cached_dev) STORE(__cached_dev) { struct cached_dev *dc = container_of(kobj, struct cached_dev, disk.kobj); unsigned v = size; struct cache_set *c; struct kobj_uevent_env *env; #define d_strtoul(var) sysfs_strtoul(var, dc->var) #define d_strtoi_h(var) sysfs_hatoi(var, dc->var) sysfs_strtoul(data_csum, dc->disk.data_csum); d_strtoul(verify); d_strtoul(writeback_metadata); d_strtoul(writeback_running); d_strtoul(writeback_delay); sysfs_strtoul_clamp(writeback_rate, dc->writeback_rate.rate, 1, 1000000); sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40); d_strtoul(writeback_rate_update_seconds); d_strtoul(writeback_rate_d_term); d_strtoul(writeback_rate_p_term_inverse); sysfs_strtoul_clamp(writeback_rate_p_term_inverse, dc->writeback_rate_p_term_inverse, 1, INT_MAX); d_strtoul(writeback_rate_d_smooth); d_strtoul(sequential_merge); d_strtoi_h(sequential_cutoff); d_strtoi_h(readahead); if (attr == &sysfs_clear_stats) bch_cache_accounting_clear(&dc->accounting); if (attr == &sysfs_running && strtoul_or_return(buf)) bch_cached_dev_run(dc); if (attr == &sysfs_cache_mode) { ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1); if (v < 0) return v; if ((unsigned) v != BDEV_CACHE_MODE(&dc->sb)) { SET_BDEV_CACHE_MODE(&dc->sb, v); bch_write_bdev_super(dc, NULL); } } if (attr == &sysfs_label) { if (size > SB_LABEL_SIZE) return -EINVAL; memcpy(dc->sb.label, buf, size); if (size < SB_LABEL_SIZE) dc->sb.label[size] = '\0'; if (size && dc->sb.label[size - 1] == '\n') dc->sb.label[size - 1] = '\0'; bch_write_bdev_super(dc, NULL); if (dc->disk.c) { memcpy(dc->disk.c->uuids[dc->disk.id].label, buf, SB_LABEL_SIZE); bch_uuid_write(dc->disk.c); } env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); if (!env) return -ENOMEM; add_uevent_var(env, "DRIVER=bcache"); add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid), add_uevent_var(env, "CACHED_LABEL=%s", buf); kobject_uevent_env( &disk_to_dev(dc->disk.disk)->kobj, KOBJ_CHANGE, env->envp); kfree(env); } if (attr == &sysfs_attach) { if (bch_parse_uuid(buf, dc->sb.set_uuid) < 16) return -EINVAL; list_for_each_entry(c, &bch_cache_sets, list) { v = bch_cached_dev_attach(dc, c); if (!v) return size; } pr_err("Can't attach %s: cache set not found", buf); size = v; } if (attr == &sysfs_detach && dc->disk.c) bch_cached_dev_detach(dc); if (attr == &sysfs_stop) bcache_device_stop(&dc->disk); return size; } STORE(bch_cached_dev) { struct cached_dev *dc = container_of(kobj, struct cached_dev, disk.kobj); mutex_lock(&bch_register_lock); size = __cached_dev_store(kobj, attr, buf, size); if (attr == &sysfs_writeback_running) bch_writeback_queue(dc); if (attr == &sysfs_writeback_percent) schedule_delayed_work(&dc->writeback_rate_update, dc->writeback_rate_update_seconds * HZ); mutex_unlock(&bch_register_lock); return size; } static struct attribute *bch_cached_dev_files[] = { &sysfs_attach, &sysfs_detach, &sysfs_stop, #if 0 &sysfs_data_csum, #endif &sysfs_cache_mode, &sysfs_writeback_metadata, &sysfs_writeback_running, &sysfs_writeback_delay, &sysfs_writeback_percent, &sysfs_writeback_rate, &sysfs_writeback_rate_update_seconds, &sysfs_writeback_rate_d_term, &sysfs_writeback_rate_p_term_inverse, &sysfs_writeback_rate_d_smooth, &sysfs_writeback_rate_debug, &sysfs_dirty_data, &sysfs_stripe_size, &sysfs_partial_stripes_expensive, &sysfs_sequential_cutoff, &sysfs_sequential_merge, &sysfs_clear_stats, &sysfs_running, &sysfs_state, &sysfs_label, &sysfs_readahead, #ifdef CONFIG_BCACHE_DEBUG &sysfs_verify, #endif NULL }; KTYPE(bch_cached_dev); SHOW(bch_flash_dev) { struct bcache_device *d = container_of(kobj, struct bcache_device, kobj); struct uuid_entry *u = &d->c->uuids[d->id]; sysfs_printf(data_csum, "%i", d->data_csum); sysfs_hprint(size, u->sectors << 9); if (attr == &sysfs_label) { memcpy(buf, u->label, SB_LABEL_SIZE); buf[SB_LABEL_SIZE + 1] = '\0'; strcat(buf, "\n"); return strlen(buf); } return 0; } STORE(__bch_flash_dev) { struct bcache_device *d = container_of(kobj, struct bcache_device, kobj); struct uuid_entry *u = &d->c->uuids[d->id]; sysfs_strtoul(data_csum, d->data_csum); if (attr == &sysfs_size) { uint64_t v; strtoi_h_or_return(buf, v); u->sectors = v >> 9; bch_uuid_write(d->c); set_capacity(d->disk, u->sectors); } if (attr == &sysfs_label) { memcpy(u->label, buf, SB_LABEL_SIZE); bch_uuid_write(d->c); } if (attr == &sysfs_unregister) { atomic_set(&d->detaching, 1); bcache_device_stop(d); } return size; } STORE_LOCKED(bch_flash_dev) static struct attribute *bch_flash_dev_files[] = { &sysfs_unregister, #if 0 &sysfs_data_csum, #endif &sysfs_label, &sysfs_size, NULL }; KTYPE(bch_flash_dev); SHOW(__bch_cache_set) { unsigned root_usage(struct cache_set *c) { unsigned bytes = 0; struct bkey *k; struct btree *b; struct btree_iter iter; goto lock_root; do { rw_unlock(false, b); lock_root: b = c->root; rw_lock(false, b, b->level); } while (b != c->root); for_each_key_filter(b, k, &iter, bch_ptr_bad) bytes += bkey_bytes(k); rw_unlock(false, b); return (bytes * 100) / btree_bytes(c); } size_t cache_size(struct cache_set *c) { size_t ret = 0; struct btree *b; mutex_lock(&c->bucket_lock); list_for_each_entry(b, &c->btree_cache, list) ret += 1 << (b->page_order + PAGE_SHIFT); mutex_unlock(&c->bucket_lock); return ret; } unsigned cache_max_chain(struct cache_set *c) { unsigned ret = 0; struct hlist_head *h; mutex_lock(&c->bucket_lock); for (h = c->bucket_hash; h < c->bucket_hash + (1 << BUCKET_HASH_BITS); h++) { unsigned i = 0; struct hlist_node *p; hlist_for_each(p, h) i++; ret = max(ret, i); } mutex_unlock(&c->bucket_lock); return ret; } unsigned btree_used(struct cache_set *c) { return div64_u64(c->gc_stats.key_bytes * 100, (c->gc_stats.nodes ?: 1) * btree_bytes(c)); } unsigned average_key_size(struct cache_set *c) { return c->gc_stats.nkeys ? div64_u64(c->gc_stats.data, c->gc_stats.nkeys) : 0; } struct cache_set *c = container_of(kobj, struct cache_set, kobj); sysfs_print(synchronous, CACHE_SYNC(&c->sb)); sysfs_print(journal_delay_ms, c->journal_delay_ms); sysfs_hprint(bucket_size, bucket_bytes(c)); sysfs_hprint(block_size, block_bytes(c)); sysfs_print(tree_depth, c->root->level); sysfs_print(root_usage_percent, root_usage(c)); sysfs_hprint(btree_cache_size, cache_size(c)); sysfs_print(btree_cache_max_chain, cache_max_chain(c)); sysfs_print(cache_available_percent, 100 - c->gc_stats.in_use); sysfs_print_time_stats(&c->btree_gc_time, btree_gc, sec, ms); sysfs_print_time_stats(&c->btree_split_time, btree_split, sec, us); sysfs_print_time_stats(&c->sort_time, btree_sort, ms, us); sysfs_print_time_stats(&c->btree_read_time, btree_read, ms, us); sysfs_print_time_stats(&c->try_harder_time, try_harder, ms, us); sysfs_print(btree_used_percent, btree_used(c)); sysfs_print(btree_nodes, c->gc_stats.nodes); sysfs_hprint(dirty_data, c->gc_stats.dirty); sysfs_hprint(average_key_size, average_key_size(c)); sysfs_print(cache_read_races, atomic_long_read(&c->cache_read_races)); sysfs_print(writeback_keys_done, atomic_long_read(&c->writeback_keys_done)); sysfs_print(writeback_keys_failed, atomic_long_read(&c->writeback_keys_failed)); if (attr == &sysfs_errors) return bch_snprint_string_list(buf, PAGE_SIZE, error_actions, c->on_error); /* See count_io_errors for why 88 */ sysfs_print(io_error_halflife, c->error_decay * 88); sysfs_print(io_error_limit, c->error_limit >> IO_ERROR_SHIFT); sysfs_hprint(congested, ((uint64_t) bch_get_congested(c)) << 9); sysfs_print(congested_read_threshold_us, c->congested_read_threshold_us); sysfs_print(congested_write_threshold_us, c->congested_write_threshold_us); sysfs_print(active_journal_entries, fifo_used(&c->journal.pin)); sysfs_printf(verify, "%i", c->verify); sysfs_printf(key_merging_disabled, "%i", c->key_merging_disabled); sysfs_printf(gc_always_rewrite, "%i", c->gc_always_rewrite); sysfs_printf(btree_shrinker_disabled, "%i", c->shrinker_disabled); sysfs_printf(copy_gc_enabled, "%i", c->copy_gc_enabled); if (attr == &sysfs_bset_tree_stats) return bch_bset_print_stats(c, buf); return 0; } SHOW_LOCKED(bch_cache_set) STORE(__bch_cache_set) { struct cache_set *c = container_of(kobj, struct cache_set, kobj); if (attr == &sysfs_unregister) bch_cache_set_unregister(c); if (attr == &sysfs_stop) bch_cache_set_stop(c); if (attr == &sysfs_synchronous) { bool sync = strtoul_or_return(buf); if (sync != CACHE_SYNC(&c->sb)) { SET_CACHE_SYNC(&c->sb, sync); bcache_write_super(c); } } if (attr == &sysfs_flash_vol_create) { int r; uint64_t v; strtoi_h_or_return(buf, v); r = bch_flash_dev_create(c, v); if (r) return r; } if (attr == &sysfs_clear_stats) { atomic_long_set(&c->writeback_keys_done, 0); atomic_long_set(&c->writeback_keys_failed, 0); memset(&c->gc_stats, 0, sizeof(struct gc_stat)); bch_cache_accounting_clear(&c->accounting); } if (attr == &sysfs_trigger_gc) bch_queue_gc(c); if (attr == &sysfs_prune_cache) { struct shrink_control sc; sc.gfp_mask = GFP_KERNEL; sc.nr_to_scan = strtoul_or_return(buf); c->shrink.scan_objects(&c->shrink, &sc); } sysfs_strtoul(congested_read_threshold_us, c->congested_read_threshold_us); sysfs_strtoul(congested_write_threshold_us, c->congested_write_threshold_us); if (attr == &sysfs_errors) { ssize_t v = bch_read_string_list(buf, error_actions); if (v < 0) return v; c->on_error = v; } if (attr == &sysfs_io_error_limit) c->error_limit = strtoul_or_return(buf) << IO_ERROR_SHIFT; /* See count_io_errors() for why 88 */ if (attr == &sysfs_io_error_halflife) c->error_decay = strtoul_or_return(buf) / 88; sysfs_strtoul(journal_delay_ms, c->journal_delay_ms); sysfs_strtoul(verify, c->verify); sysfs_strtoul(key_merging_disabled, c->key_merging_disabled); sysfs_strtoul(gc_always_rewrite, c->gc_always_rewrite); sysfs_strtoul(btree_shrinker_disabled, c->shrinker_disabled); sysfs_strtoul(copy_gc_enabled, c->copy_gc_enabled); return size; } STORE_LOCKED(bch_cache_set) SHOW(bch_cache_set_internal) { struct cache_set *c = container_of(kobj, struct cache_set, internal); return bch_cache_set_show(&c->kobj, attr, buf); } STORE(bch_cache_set_internal) { struct cache_set *c = container_of(kobj, struct cache_set, internal); return bch_cache_set_store(&c->kobj, attr, buf, size); } static void bch_cache_set_internal_release(struct kobject *k) { } static struct attribute *bch_cache_set_files[] = { &sysfs_unregister, &sysfs_stop, &sysfs_synchronous, &sysfs_journal_delay_ms, &sysfs_flash_vol_create, &sysfs_bucket_size, &sysfs_block_size, &sysfs_tree_depth, &sysfs_root_usage_percent, &sysfs_btree_cache_size, &sysfs_cache_available_percent, &sysfs_average_key_size, &sysfs_dirty_data, &sysfs_errors, &sysfs_io_error_limit, &sysfs_io_error_halflife, &sysfs_congested, &sysfs_congested_read_threshold_us, &sysfs_congested_write_threshold_us, &sysfs_clear_stats, NULL }; KTYPE(bch_cache_set); static struct attribute *bch_cache_set_internal_files[] = { &sysfs_active_journal_entries, sysfs_time_stats_attribute_list(btree_gc, sec, ms) sysfs_time_stats_attribute_list(btree_split, sec, us) sysfs_time_stats_attribute_list(btree_sort, ms, us) sysfs_time_stats_attribute_list(btree_read, ms, us) sysfs_time_stats_attribute_list(try_harder, ms, us) &sysfs_btree_nodes, &sysfs_btree_used_percent, &sysfs_btree_cache_max_chain, &sysfs_bset_tree_stats, &sysfs_cache_read_races, &sysfs_writeback_keys_done, &sysfs_writeback_keys_failed, &sysfs_trigger_gc, &sysfs_prune_cache, #ifdef CONFIG_BCACHE_DEBUG &sysfs_verify, &sysfs_key_merging_disabled, #endif &sysfs_gc_always_rewrite, &sysfs_btree_shrinker_disabled, &sysfs_copy_gc_enabled, NULL }; KTYPE(bch_cache_set_internal); SHOW(__bch_cache) { struct cache *ca = container_of(kobj, struct cache, kobj); sysfs_hprint(bucket_size, bucket_bytes(ca)); sysfs_hprint(block_size, block_bytes(ca)); sysfs_print(nbuckets, ca->sb.nbuckets); sysfs_print(discard, ca->discard); sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9); sysfs_hprint(btree_written, atomic_long_read(&ca->btree_sectors_written) << 9); sysfs_hprint(metadata_written, (atomic_long_read(&ca->meta_sectors_written) + atomic_long_read(&ca->btree_sectors_written)) << 9); sysfs_print(io_errors, atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT); sysfs_print(freelist_percent, ca->free.size * 100 / ((size_t) ca->sb.nbuckets)); if (attr == &sysfs_cache_replacement_policy) return bch_snprint_string_list(buf, PAGE_SIZE, cache_replacement_policies, CACHE_REPLACEMENT(&ca->sb)); if (attr == &sysfs_priority_stats) { int cmp(const void *l, const void *r) { return *((uint16_t *) r) - *((uint16_t *) l); } size_t n = ca->sb.nbuckets, i, unused, btree; uint64_t sum = 0; /* Compute 31 quantiles */ uint16_t q[31], *p, *cached; ssize_t ret; cached = p = vmalloc(ca->sb.nbuckets * sizeof(uint16_t)); if (!p) return -ENOMEM; mutex_lock(&ca->set->bucket_lock); for (i = ca->sb.first_bucket; i < n; i++) p[i] = ca->buckets[i].prio; mutex_unlock(&ca->set->bucket_lock); sort(p, n, sizeof(uint16_t), cmp, NULL); while (n && !cached[n - 1]) --n; unused = ca->sb.nbuckets - n; while (cached < p + n && *cached == BTREE_PRIO) cached++; btree = cached - p; n -= btree; for (i = 0; i < n; i++) sum += INITIAL_PRIO - cached[i]; if (n) do_div(sum, n); for (i = 0; i < ARRAY_SIZE(q); i++) q[i] = INITIAL_PRIO - cached[n * (i + 1) / (ARRAY_SIZE(q) + 1)]; vfree(p); ret = scnprintf(buf, PAGE_SIZE, "Unused: %zu%%\n" "Metadata: %zu%%\n" "Average: %llu\n" "Sectors per Q: %zu\n" "Quantiles: [", unused * 100 / (size_t) ca->sb.nbuckets, btree * 100 / (size_t) ca->sb.nbuckets, sum, n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1)); for (i = 0; i < ARRAY_SIZE(q); i++) ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u ", q[i]); ret--; ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n"); return ret; } return 0; } SHOW_LOCKED(bch_cache) STORE(__bch_cache) { struct cache *ca = container_of(kobj, struct cache, kobj); if (attr == &sysfs_discard) { bool v = strtoul_or_return(buf); if (blk_queue_discard(bdev_get_queue(ca->bdev))) ca->discard = v; if (v != CACHE_DISCARD(&ca->sb)) { SET_CACHE_DISCARD(&ca->sb, v); bcache_write_super(ca->set); } } if (attr == &sysfs_cache_replacement_policy) { ssize_t v = bch_read_string_list(buf, cache_replacement_policies); if (v < 0) return v; if ((unsigned) v != CACHE_REPLACEMENT(&ca->sb)) { mutex_lock(&ca->set->bucket_lock); SET_CACHE_REPLACEMENT(&ca->sb, v); mutex_unlock(&ca->set->bucket_lock); bcache_write_super(ca->set); } } if (attr == &sysfs_freelist_percent) { DECLARE_FIFO(long, free); long i; size_t p = strtoul_or_return(buf); p = clamp_t(size_t, ((size_t) ca->sb.nbuckets * p) / 100, roundup_pow_of_two(ca->sb.nbuckets) >> 9, ca->sb.nbuckets / 2); if (!init_fifo_exact(&free, p, GFP_KERNEL)) return -ENOMEM; mutex_lock(&ca->set->bucket_lock); fifo_move(&free, &ca->free); fifo_swap(&free, &ca->free); mutex_unlock(&ca->set->bucket_lock); while (fifo_pop(&free, i)) atomic_dec(&ca->buckets[i].pin); free_fifo(&free); } if (attr == &sysfs_clear_stats) { atomic_long_set(&ca->sectors_written, 0); atomic_long_set(&ca->btree_sectors_written, 0); atomic_long_set(&ca->meta_sectors_written, 0); atomic_set(&ca->io_count, 0); atomic_set(&ca->io_errors, 0); } return size; } STORE_LOCKED(bch_cache) static struct attribute *bch_cache_files[] = { &sysfs_bucket_size, &sysfs_block_size, &sysfs_nbuckets, &sysfs_priority_stats, &sysfs_discard, &sysfs_written, &sysfs_btree_written, &sysfs_metadata_written, &sysfs_io_errors, &sysfs_clear_stats, &sysfs_freelist_percent, &sysfs_cache_replacement_policy, NULL }; KTYPE(bch_cache);