drivers/md/bcache/sysfs.c

   1 /*
   2  * bcache sysfs interfaces
   3  *
   4  * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
   5  * Copyright 2012 Google, Inc.
   6  */
   7
   8 #include "bcache.h"
   9 #include "sysfs.h"
  10 #include "btree.h"
  11 #include "request.h"
  12 #include "writeback.h"
  13
  14 #include <linux/blkdev.h>
  15 #include <linux/sort.h>
  16
  17 static const char * const cache_replacement_policies[] = {
  18         "lru",
  19         "fifo",
  20         "random",
  21         NULL
  22 };
  23
  24 write_attribute(attach);
  25 write_attribute(detach);
  26 write_attribute(unregister);
  27 write_attribute(stop);
  28 write_attribute(clear_stats);
  29 write_attribute(trigger_gc);
  30 write_attribute(prune_cache);
  31 write_attribute(flash_vol_create);
  32
  33 read_attribute(bucket_size);
  34 read_attribute(block_size);
  35 read_attribute(nbuckets);
  36 read_attribute(tree_depth);
  37 read_attribute(root_usage_percent);
  38 read_attribute(priority_stats);
  39 read_attribute(btree_cache_size);
  40 read_attribute(btree_cache_max_chain);
  41 read_attribute(cache_available_percent);
  42 read_attribute(written);
  43 read_attribute(btree_written);
  44 read_attribute(metadata_written);
  45 read_attribute(active_journal_entries);
  46
  47 sysfs_time_stats_attribute(btree_gc,    sec, ms);
  48 sysfs_time_stats_attribute(btree_split, sec, us);
  49 sysfs_time_stats_attribute(btree_sort,  ms,  us);
  50 sysfs_time_stats_attribute(btree_read,  ms,  us);
  51 sysfs_time_stats_attribute(try_harder,  ms,  us);
  52
  53 read_attribute(btree_nodes);
  54 read_attribute(btree_used_percent);
  55 read_attribute(average_key_size);
  56 read_attribute(dirty_data);
  57 read_attribute(bset_tree_stats);
  58
  59 read_attribute(state);
  60 read_attribute(cache_read_races);
  61 read_attribute(writeback_keys_done);
  62 read_attribute(writeback_keys_failed);
  63 read_attribute(io_errors);
  64 read_attribute(congested);
  65 rw_attribute(congested_read_threshold_us);
  66 rw_attribute(congested_write_threshold_us);
  67
  68 rw_attribute(sequential_cutoff);
  69 rw_attribute(sequential_merge);
  70 rw_attribute(data_csum);
  71 rw_attribute(cache_mode);
  72 rw_attribute(writeback_metadata);
  73 rw_attribute(writeback_running);
  74 rw_attribute(writeback_percent);
  75 rw_attribute(writeback_delay);
  76 rw_attribute(writeback_rate);
  77
  78 rw_attribute(writeback_rate_update_seconds);
  79 rw_attribute(writeback_rate_d_term);
  80 rw_attribute(writeback_rate_p_term_inverse);
  81 rw_attribute(writeback_rate_d_smooth);
  82 read_attribute(writeback_rate_debug);
  83
  84 read_attribute(stripe_size);
  85 read_attribute(partial_stripes_expensive);
  86
  87 rw_attribute(synchronous);
  88 rw_attribute(journal_delay_ms);
  89 rw_attribute(discard);
  90 rw_attribute(running);
  91 rw_attribute(label);
  92 rw_attribute(readahead);
  93 rw_attribute(io_error_limit);
  94 rw_attribute(io_error_halflife);
  95 rw_attribute(verify);
  96 rw_attribute(key_merging_disabled);
  97 rw_attribute(gc_always_rewrite);
  98 rw_attribute(freelist_percent);
  99 rw_attribute(cache_replacement_policy);
 100 rw_attribute(btree_shrinker_disabled);
 101 rw_attribute(copy_gc_enabled);
 102 rw_attribute(size);
 103
 104 SHOW(__bch_cached_dev)
 105 {
 106         struct cached_dev *dc = container_of(kobj, struct cached_dev,
 107                                              disk.kobj);
 108         const char *states[] = { "no cache", "clean", "dirty", "inconsistent" };
 109
 110 #define var(stat)               (dc->stat)
 111
 112         if (attr == &sysfs_cache_mode)
 113                 return bch_snprint_string_list(buf, PAGE_SIZE,
 114                                                bch_cache_modes + 1,
 115                                                BDEV_CACHE_MODE(&dc->sb));
 116
 117         sysfs_printf(data_csum,         "%i", dc->disk.data_csum);
 118         var_printf(verify,              "%i");
 119         var_printf(writeback_metadata,  "%i");
 120         var_printf(writeback_running,   "%i");
 121         var_print(writeback_delay);
 122         var_print(writeback_percent);
 123         sysfs_print(writeback_rate,     dc->writeback_rate.rate);
 124
 125         var_print(writeback_rate_update_seconds);
 126         var_print(writeback_rate_d_term);
 127         var_print(writeback_rate_p_term_inverse);
 128         var_print(writeback_rate_d_smooth);
 129
 130         if (attr == &sysfs_writeback_rate_debug) {
 131                 char dirty[20];
 132                 char derivative[20];
 133                 char target[20];
 134                 bch_hprint(dirty,
 135                            bcache_dev_sectors_dirty(&dc->disk) << 9);
 136                 bch_hprint(derivative,  dc->writeback_rate_derivative << 9);
 137                 bch_hprint(target,      dc->writeback_rate_target << 9);
 138
 139                 return sprintf(buf,
 140                                "rate:\t\t%u\n"
 141                                "change:\t\t%i\n"
 142                                "dirty:\t\t%s\n"
 143                                "derivative:\t%s\n"
 144                                "target:\t\t%s\n",
 145                                dc->writeback_rate.rate,
 146                                dc->writeback_rate_change,
 147                                dirty, derivative, target);
 148         }
 149
 150         sysfs_hprint(dirty_data,
 151                      bcache_dev_sectors_dirty(&dc->disk) << 9);
 152
 153         sysfs_hprint(stripe_size,       (1 << dc->disk.stripe_size_bits) << 9);
 154         var_printf(partial_stripes_expensive,   "%u");
 155
 156         var_printf(sequential_merge,    "%i");
 157         var_hprint(sequential_cutoff);
 158         var_hprint(readahead);
 159
 160         sysfs_print(running,            atomic_read(&dc->running));
 161         sysfs_print(state,              states[BDEV_STATE(&dc->sb)]);
 162
 163         if (attr == &sysfs_label) {
 164                 memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
 165                 buf[SB_LABEL_SIZE + 1] = '\0';
 166                 strcat(buf, "\n");
 167                 return strlen(buf);
 168         }
 169
 170 #undef var
 171         return 0;
 172 }
 173 SHOW_LOCKED(bch_cached_dev)
 174
 175 STORE(__cached_dev)
 176 {
 177         struct cached_dev *dc = container_of(kobj, struct cached_dev,
 178                                              disk.kobj);
 179         unsigned v = size;
 180         struct cache_set *c;
 181         struct kobj_uevent_env *env;
 182
 183 #define d_strtoul(var)          sysfs_strtoul(var, dc->var)
 184 #define d_strtoi_h(var)         sysfs_hatoi(var, dc->var)
 185
 186         sysfs_strtoul(data_csum,        dc->disk.data_csum);
 187         d_strtoul(verify);
 188         d_strtoul(writeback_metadata);
 189         d_strtoul(writeback_running);
 190         d_strtoul(writeback_delay);
 191         sysfs_strtoul_clamp(writeback_rate,
 192                             dc->writeback_rate.rate, 1, 1000000);
 193         sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent, 0, 40);
 194
 195         d_strtoul(writeback_rate_update_seconds);
 196         d_strtoul(writeback_rate_d_term);
 197         d_strtoul(writeback_rate_p_term_inverse);
 198         sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
 199                             dc->writeback_rate_p_term_inverse, 1, INT_MAX);
 200         d_strtoul(writeback_rate_d_smooth);
 201
 202         d_strtoul(sequential_merge);
 203         d_strtoi_h(sequential_cutoff);
 204         d_strtoi_h(readahead);
 205
 206         if (attr == &sysfs_clear_stats)
 207                 bch_cache_accounting_clear(&dc->accounting);
 208
 209         if (attr == &sysfs_running &&
 210             strtoul_or_return(buf))
 211                 bch_cached_dev_run(dc);
 212
 213         if (attr == &sysfs_cache_mode) {
 214                 ssize_t v = bch_read_string_list(buf, bch_cache_modes + 1);
 215
 216                 if (v < 0)
 217                         return v;
 218
 219                 if ((unsigned) v != BDEV_CACHE_MODE(&dc->sb)) {
 220                         SET_BDEV_CACHE_MODE(&dc->sb, v);
 221                         bch_write_bdev_super(dc, NULL);
 222                 }
 223         }
 224
 225         if (attr == &sysfs_label) {
 226                 /* note: endlines are preserved */
 227                 memcpy(dc->sb.label, buf, SB_LABEL_SIZE);
 228                 bch_write_bdev_super(dc, NULL);
 229                 if (dc->disk.c) {
 230                         memcpy(dc->disk.c->uuids[dc->disk.id].label,
 231                                buf, SB_LABEL_SIZE);
 232                         bch_uuid_write(dc->disk.c);
 233                 }
 234                 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
 235                 add_uevent_var(env, "DRIVER=bcache");
 236                 add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid),
 237                 add_uevent_var(env, "CACHED_LABEL=%s", buf);
 238                 kobject_uevent_env(
 239                         &disk_to_dev(dc->disk.disk)->kobj, KOBJ_CHANGE, env->envp);
 240                 kfree(env);
 241         }
 242
 243         if (attr == &sysfs_attach) {
 244                 if (bch_parse_uuid(buf, dc->sb.set_uuid) < 16)
 245                         return -EINVAL;
 246
 247                 list_for_each_entry(c, &bch_cache_sets, list) {
 248                         v = bch_cached_dev_attach(dc, c);
 249                         if (!v)
 250                                 return size;
 251                 }
 252
 253                 pr_err("Can't attach %s: cache set not found", buf);
 254                 size = v;
 255         }
 256
 257         if (attr == &sysfs_detach && dc->disk.c)
 258                 bch_cached_dev_detach(dc);
 259
 260         if (attr == &sysfs_stop)
 261                 bcache_device_stop(&dc->disk);
 262
 263         return size;
 264 }
 265
 266 STORE(bch_cached_dev)
 267 {
 268         struct cached_dev *dc = container_of(kobj, struct cached_dev,
 269                                              disk.kobj);
 270
 271         mutex_lock(&bch_register_lock);
 272         size = __cached_dev_store(kobj, attr, buf, size);
 273
 274         if (attr == &sysfs_writeback_running)
 275                 bch_writeback_queue(dc);
 276
 277         if (attr == &sysfs_writeback_percent)
 278                 schedule_delayed_work(&dc->writeback_rate_update,
 279                                       dc->writeback_rate_update_seconds * HZ);
 280
 281         mutex_unlock(&bch_register_lock);
 282         return size;
 283 }
 284
 285 static struct attribute *bch_cached_dev_files[] = {
 286         &sysfs_attach,
 287         &sysfs_detach,
 288         &sysfs_stop,
 289 #if 0
 290         &sysfs_data_csum,
 291 #endif
 292         &sysfs_cache_mode,
 293         &sysfs_writeback_metadata,
 294         &sysfs_writeback_running,
 295         &sysfs_writeback_delay,
 296         &sysfs_writeback_percent,
 297         &sysfs_writeback_rate,
 298         &sysfs_writeback_rate_update_seconds,
 299         &sysfs_writeback_rate_d_term,
 300         &sysfs_writeback_rate_p_term_inverse,
 301         &sysfs_writeback_rate_d_smooth,
 302         &sysfs_writeback_rate_debug,
 303         &sysfs_dirty_data,
 304         &sysfs_stripe_size,
 305         &sysfs_partial_stripes_expensive,
 306         &sysfs_sequential_cutoff,
 307         &sysfs_sequential_merge,
 308         &sysfs_clear_stats,
 309         &sysfs_running,
 310         &sysfs_state,
 311         &sysfs_label,
 312         &sysfs_readahead,
 313 #ifdef CONFIG_BCACHE_DEBUG
 314         &sysfs_verify,
 315 #endif
 316         NULL
 317 };
 318 KTYPE(bch_cached_dev);
 319
 320 SHOW(bch_flash_dev)
 321 {
 322         struct bcache_device *d = container_of(kobj, struct bcache_device,
 323                                                kobj);
 324         struct uuid_entry *u = &d->c->uuids[d->id];
 325
 326         sysfs_printf(data_csum, "%i", d->data_csum);
 327         sysfs_hprint(size,      u->sectors << 9);
 328
 329         if (attr == &sysfs_label) {
 330                 memcpy(buf, u->label, SB_LABEL_SIZE);
 331                 buf[SB_LABEL_SIZE + 1] = '\0';
 332                 strcat(buf, "\n");
 333                 return strlen(buf);
 334         }
 335
 336         return 0;
 337 }
 338
 339 STORE(__bch_flash_dev)
 340 {
 341         struct bcache_device *d = container_of(kobj, struct bcache_device,
 342                                                kobj);
 343         struct uuid_entry *u = &d->c->uuids[d->id];
 344
 345         sysfs_strtoul(data_csum,        d->data_csum);
 346
 347         if (attr == &sysfs_size) {
 348                 uint64_t v;
 349                 strtoi_h_or_return(buf, v);
 350
 351                 u->sectors = v >> 9;
 352                 bch_uuid_write(d->c);
 353                 set_capacity(d->disk, u->sectors);
 354         }
 355
 356         if (attr == &sysfs_label) {
 357                 memcpy(u->label, buf, SB_LABEL_SIZE);
 358                 bch_uuid_write(d->c);
 359         }
 360
 361         if (attr == &sysfs_unregister) {
 362                 atomic_set(&d->detaching, 1);
 363                 bcache_device_stop(d);
 364         }
 365
 366         return size;
 367 }
 368 STORE_LOCKED(bch_flash_dev)
 369
 370 static struct attribute *bch_flash_dev_files[] = {
 371         &sysfs_unregister,
 372 #if 0
 373         &sysfs_data_csum,
 374 #endif
 375         &sysfs_label,
 376         &sysfs_size,
 377         NULL
 378 };
 379 KTYPE(bch_flash_dev);
 380
 381 SHOW(__bch_cache_set)
 382 {
 383         unsigned root_usage(struct cache_set *c)
 384         {
 385                 unsigned bytes = 0;
 386                 struct bkey *k;
 387                 struct btree *b;
 388                 struct btree_iter iter;
 389
 390                 goto lock_root;
 391
 392                 do {
 393                         rw_unlock(false, b);
 394 lock_root:
 395                         b = c->root;
 396                         rw_lock(false, b, b->level);
 397                 } while (b != c->root);
 398
 399                 for_each_key_filter(b, k, &iter, bch_ptr_bad)
 400                         bytes += bkey_bytes(k);
 401
 402                 rw_unlock(false, b);
 403
 404                 return (bytes * 100) / btree_bytes(c);
 405         }
 406
 407         size_t cache_size(struct cache_set *c)
 408         {
 409                 size_t ret = 0;
 410                 struct btree *b;
 411
 412                 mutex_lock(&c->bucket_lock);
 413                 list_for_each_entry(b, &c->btree_cache, list)
 414                         ret += 1 << (b->page_order + PAGE_SHIFT);
 415
 416                 mutex_unlock(&c->bucket_lock);
 417                 return ret;
 418         }
 419
 420         unsigned cache_max_chain(struct cache_set *c)
 421         {
 422                 unsigned ret = 0;
 423                 struct hlist_head *h;
 424
 425                 mutex_lock(&c->bucket_lock);
 426
 427                 for (h = c->bucket_hash;
 428                      h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
 429                      h++) {
 430                         unsigned i = 0;
 431                         struct hlist_node *p;
 432
 433                         hlist_for_each(p, h)
 434                                 i++;
 435
 436                         ret = max(ret, i);
 437                 }
 438
 439                 mutex_unlock(&c->bucket_lock);
 440                 return ret;
 441         }
 442
 443         unsigned btree_used(struct cache_set *c)
 444         {
 445                 return div64_u64(c->gc_stats.key_bytes * 100,
 446                                  (c->gc_stats.nodes ?: 1) * btree_bytes(c));
 447         }
 448
 449         unsigned average_key_size(struct cache_set *c)
 450         {
 451                 return c->gc_stats.nkeys
 452                         ? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
 453                         : 0;
 454         }
 455
 456         struct cache_set *c = container_of(kobj, struct cache_set, kobj);
 457
 458         sysfs_print(synchronous,                CACHE_SYNC(&c->sb));
 459         sysfs_print(journal_delay_ms,           c->journal_delay_ms);
 460         sysfs_hprint(bucket_size,               bucket_bytes(c));
 461         sysfs_hprint(block_size,                block_bytes(c));
 462         sysfs_print(tree_depth,                 c->root->level);
 463         sysfs_print(root_usage_percent,         root_usage(c));
 464
 465         sysfs_hprint(btree_cache_size,          cache_size(c));
 466         sysfs_print(btree_cache_max_chain,      cache_max_chain(c));
 467         sysfs_print(cache_available_percent,    100 - c->gc_stats.in_use);
 468
 469         sysfs_print_time_stats(&c->btree_gc_time,       btree_gc, sec, ms);
 470         sysfs_print_time_stats(&c->btree_split_time,    btree_split, sec, us);
 471         sysfs_print_time_stats(&c->sort_time,           btree_sort, ms, us);
 472         sysfs_print_time_stats(&c->btree_read_time,     btree_read, ms, us);
 473         sysfs_print_time_stats(&c->try_harder_time,     try_harder, ms, us);
 474
 475         sysfs_print(btree_used_percent, btree_used(c));
 476         sysfs_print(btree_nodes,        c->gc_stats.nodes);
 477         sysfs_hprint(dirty_data,        c->gc_stats.dirty);
 478         sysfs_hprint(average_key_size,  average_key_size(c));
 479
 480         sysfs_print(cache_read_races,
 481                     atomic_long_read(&c->cache_read_races));
 482
 483         sysfs_print(writeback_keys_done,
 484                     atomic_long_read(&c->writeback_keys_done));
 485         sysfs_print(writeback_keys_failed,
 486                     atomic_long_read(&c->writeback_keys_failed));
 487
 488         /* See count_io_errors for why 88 */
 489         sysfs_print(io_error_halflife,  c->error_decay * 88);
 490         sysfs_print(io_error_limit,     c->error_limit >> IO_ERROR_SHIFT);
 491
 492         sysfs_hprint(congested,
 493                      ((uint64_t) bch_get_congested(c)) << 9);
 494         sysfs_print(congested_read_threshold_us,
 495                     c->congested_read_threshold_us);
 496         sysfs_print(congested_write_threshold_us,
 497                     c->congested_write_threshold_us);
 498
 499         sysfs_print(active_journal_entries,     fifo_used(&c->journal.pin));
 500         sysfs_printf(verify,                    "%i", c->verify);
 501         sysfs_printf(key_merging_disabled,      "%i", c->key_merging_disabled);
 502         sysfs_printf(gc_always_rewrite,         "%i", c->gc_always_rewrite);
 503         sysfs_printf(btree_shrinker_disabled,   "%i", c->shrinker_disabled);
 504         sysfs_printf(copy_gc_enabled,           "%i", c->copy_gc_enabled);
 505
 506         if (attr == &sysfs_bset_tree_stats)
 507                 return bch_bset_print_stats(c, buf);
 508
 509         return 0;
 510 }
 511 SHOW_LOCKED(bch_cache_set)
 512
 513 STORE(__bch_cache_set)
 514 {
 515         struct cache_set *c = container_of(kobj, struct cache_set, kobj);
 516
 517         if (attr == &sysfs_unregister)
 518                 bch_cache_set_unregister(c);
 519
 520         if (attr == &sysfs_stop)
 521                 bch_cache_set_stop(c);
 522
 523         if (attr == &sysfs_synchronous) {
 524                 bool sync = strtoul_or_return(buf);
 525
 526                 if (sync != CACHE_SYNC(&c->sb)) {
 527                         SET_CACHE_SYNC(&c->sb, sync);
 528                         bcache_write_super(c);
 529                 }
 530         }
 531
 532         if (attr == &sysfs_flash_vol_create) {
 533                 int r;
 534                 uint64_t v;
 535                 strtoi_h_or_return(buf, v);
 536
 537                 r = bch_flash_dev_create(c, v);
 538                 if (r)
 539                         return r;
 540         }
 541
 542         if (attr == &sysfs_clear_stats) {
 543                 atomic_long_set(&c->writeback_keys_done,        0);
 544                 atomic_long_set(&c->writeback_keys_failed,      0);
 545
 546                 memset(&c->gc_stats, 0, sizeof(struct gc_stat));
 547                 bch_cache_accounting_clear(&c->accounting);
 548         }
 549
 550         if (attr == &sysfs_trigger_gc)
 551                 bch_queue_gc(c);
 552
 553         if (attr == &sysfs_prune_cache) {
 554                 struct shrink_control sc;
 555                 sc.gfp_mask = GFP_KERNEL;
 556                 sc.nr_to_scan = strtoul_or_return(buf);
 557                 c->shrink.shrink(&c->shrink, &sc);
 558         }
 559
 560         sysfs_strtoul(congested_read_threshold_us,
 561                       c->congested_read_threshold_us);
 562         sysfs_strtoul(congested_write_threshold_us,
 563                       c->congested_write_threshold_us);
 564
 565         if (attr == &sysfs_io_error_limit)
 566                 c->error_limit = strtoul_or_return(buf) << IO_ERROR_SHIFT;
 567
 568         /* See count_io_errors() for why 88 */
 569         if (attr == &sysfs_io_error_halflife)
 570                 c->error_decay = strtoul_or_return(buf) / 88;
 571
 572         sysfs_strtoul(journal_delay_ms,         c->journal_delay_ms);
 573         sysfs_strtoul(verify,                   c->verify);
 574         sysfs_strtoul(key_merging_disabled,     c->key_merging_disabled);
 575         sysfs_strtoul(gc_always_rewrite,        c->gc_always_rewrite);
 576         sysfs_strtoul(btree_shrinker_disabled,  c->shrinker_disabled);
 577         sysfs_strtoul(copy_gc_enabled,          c->copy_gc_enabled);
 578
 579         return size;
 580 }
 581 STORE_LOCKED(bch_cache_set)
 582
 583 SHOW(bch_cache_set_internal)
 584 {
 585         struct cache_set *c = container_of(kobj, struct cache_set, internal);
 586         return bch_cache_set_show(&c->kobj, attr, buf);
 587 }
 588
 589 STORE(bch_cache_set_internal)
 590 {
 591         struct cache_set *c = container_of(kobj, struct cache_set, internal);
 592         return bch_cache_set_store(&c->kobj, attr, buf, size);
 593 }
 594
 595 static void bch_cache_set_internal_release(struct kobject *k)
 596 {
 597 }
 598
 599 static struct attribute *bch_cache_set_files[] = {
 600         &sysfs_unregister,
 601         &sysfs_stop,
 602         &sysfs_synchronous,
 603         &sysfs_journal_delay_ms,
 604         &sysfs_flash_vol_create,
 605
 606         &sysfs_bucket_size,
 607         &sysfs_block_size,
 608         &sysfs_tree_depth,
 609         &sysfs_root_usage_percent,
 610         &sysfs_btree_cache_size,
 611         &sysfs_cache_available_percent,
 612
 613         &sysfs_average_key_size,
 614         &sysfs_dirty_data,
 615
 616         &sysfs_io_error_limit,
 617         &sysfs_io_error_halflife,
 618         &sysfs_congested,
 619         &sysfs_congested_read_threshold_us,
 620         &sysfs_congested_write_threshold_us,
 621         &sysfs_clear_stats,
 622         NULL
 623 };
 624 KTYPE(bch_cache_set);
 625
 626 static struct attribute *bch_cache_set_internal_files[] = {
 627         &sysfs_active_journal_entries,
 628
 629         sysfs_time_stats_attribute_list(btree_gc, sec, ms)
 630         sysfs_time_stats_attribute_list(btree_split, sec, us)
 631         sysfs_time_stats_attribute_list(btree_sort, ms, us)
 632         sysfs_time_stats_attribute_list(btree_read, ms, us)
 633         sysfs_time_stats_attribute_list(try_harder, ms, us)
 634
 635         &sysfs_btree_nodes,
 636         &sysfs_btree_used_percent,
 637         &sysfs_btree_cache_max_chain,
 638
 639         &sysfs_bset_tree_stats,
 640         &sysfs_cache_read_races,
 641         &sysfs_writeback_keys_done,
 642         &sysfs_writeback_keys_failed,
 643
 644         &sysfs_trigger_gc,
 645         &sysfs_prune_cache,
 646 #ifdef CONFIG_BCACHE_DEBUG
 647         &sysfs_verify,
 648         &sysfs_key_merging_disabled,
 649 #endif
 650         &sysfs_gc_always_rewrite,
 651         &sysfs_btree_shrinker_disabled,
 652         &sysfs_copy_gc_enabled,
 653         NULL
 654 };
 655 KTYPE(bch_cache_set_internal);
 656
 657 SHOW(__bch_cache)
 658 {
 659         struct cache *ca = container_of(kobj, struct cache, kobj);
 660
 661         sysfs_hprint(bucket_size,       bucket_bytes(ca));
 662         sysfs_hprint(block_size,        block_bytes(ca));
 663         sysfs_print(nbuckets,           ca->sb.nbuckets);
 664         sysfs_print(discard,            ca->discard);
 665         sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
 666         sysfs_hprint(btree_written,
 667                      atomic_long_read(&ca->btree_sectors_written) << 9);
 668         sysfs_hprint(metadata_written,
 669                      (atomic_long_read(&ca->meta_sectors_written) +
 670                       atomic_long_read(&ca->btree_sectors_written)) << 9);
 671
 672         sysfs_print(io_errors,
 673                     atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
 674
 675         sysfs_print(freelist_percent, ca->free.size * 100 /
 676                     ((size_t) ca->sb.nbuckets));
 677
 678         if (attr == &sysfs_cache_replacement_policy)
 679                 return bch_snprint_string_list(buf, PAGE_SIZE,
 680                                                cache_replacement_policies,
 681                                                CACHE_REPLACEMENT(&ca->sb));
 682
 683         if (attr == &sysfs_priority_stats) {
 684                 int cmp(const void *l, const void *r)
 685                 {       return *((uint16_t *) r) - *((uint16_t *) l); }
 686
 687                 size_t n = ca->sb.nbuckets, i, unused, btree;
 688                 uint64_t sum = 0;
 689                 /* Compute 31 quantiles */
 690                 uint16_t q[31], *p, *cached;
 691                 ssize_t ret;
 692
 693                 cached = p = vmalloc(ca->sb.nbuckets * sizeof(uint16_t));
 694                 if (!p)
 695                         return -ENOMEM;
 696
 697                 mutex_lock(&ca->set->bucket_lock);
 698                 for (i = ca->sb.first_bucket; i < n; i++)
 699                         p[i] = ca->buckets[i].prio;
 700                 mutex_unlock(&ca->set->bucket_lock);
 701
 702                 sort(p, n, sizeof(uint16_t), cmp, NULL);
 703
 704                 while (n &&
 705                        !cached[n - 1])
 706                         --n;
 707
 708                 unused = ca->sb.nbuckets - n;
 709
 710                 while (cached < p + n &&
 711                        *cached == BTREE_PRIO)
 712                         cached++;
 713
 714                 btree = cached - p;
 715                 n -= btree;
 716
 717                 for (i = 0; i < n; i++)
 718                         sum += INITIAL_PRIO - cached[i];
 719
 720                 if (n)
 721                         do_div(sum, n);
 722
 723                 for (i = 0; i < ARRAY_SIZE(q); i++)
 724                         q[i] = INITIAL_PRIO - cached[n * (i + 1) /
 725                                 (ARRAY_SIZE(q) + 1)];
 726
 727                 vfree(p);
 728
 729                 ret = scnprintf(buf, PAGE_SIZE,
 730                                 "Unused:                %zu%%\n"
 731                                 "Metadata:      %zu%%\n"
 732                                 "Average:       %llu\n"
 733                                 "Sectors per Q: %zu\n"
 734                                 "Quantiles:     [",
 735                                 unused * 100 / (size_t) ca->sb.nbuckets,
 736                                 btree * 100 / (size_t) ca->sb.nbuckets, sum,
 737                                 n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
 738
 739                 for (i = 0; i < ARRAY_SIZE(q); i++)
 740                         ret += scnprintf(buf + ret, PAGE_SIZE - ret,
 741                                          "%u ", q[i]);
 742                 ret--;
 743
 744                 ret += scnprintf(buf + ret, PAGE_SIZE - ret, "]\n");
 745
 746                 return ret;
 747         }
 748
 749         return 0;
 750 }
 751 SHOW_LOCKED(bch_cache)
 752
 753 STORE(__bch_cache)
 754 {
 755         struct cache *ca = container_of(kobj, struct cache, kobj);
 756
 757         if (attr == &sysfs_discard) {
 758                 bool v = strtoul_or_return(buf);
 759
 760                 if (blk_queue_discard(bdev_get_queue(ca->bdev)))
 761                         ca->discard = v;
 762
 763                 if (v != CACHE_DISCARD(&ca->sb)) {
 764                         SET_CACHE_DISCARD(&ca->sb, v);
 765                         bcache_write_super(ca->set);
 766                 }
 767         }
 768
 769         if (attr == &sysfs_cache_replacement_policy) {
 770                 ssize_t v = bch_read_string_list(buf, cache_replacement_policies);
 771
 772                 if (v < 0)
 773                         return v;
 774
 775                 if ((unsigned) v != CACHE_REPLACEMENT(&ca->sb)) {
 776                         mutex_lock(&ca->set->bucket_lock);
 777                         SET_CACHE_REPLACEMENT(&ca->sb, v);
 778                         mutex_unlock(&ca->set->bucket_lock);
 779
 780                         bcache_write_super(ca->set);
 781                 }
 782         }
 783
 784         if (attr == &sysfs_freelist_percent) {
 785                 DECLARE_FIFO(long, free);
 786                 long i;
 787                 size_t p = strtoul_or_return(buf);
 788
 789                 p = clamp_t(size_t,
 790                             ((size_t) ca->sb.nbuckets * p) / 100,
 791                             roundup_pow_of_two(ca->sb.nbuckets) >> 9,
 792                             ca->sb.nbuckets / 2);
 793
 794                 if (!init_fifo_exact(&free, p, GFP_KERNEL))
 795                         return -ENOMEM;
 796
 797                 mutex_lock(&ca->set->bucket_lock);
 798
 799                 fifo_move(&free, &ca->free);
 800                 fifo_swap(&free, &ca->free);
 801
 802                 mutex_unlock(&ca->set->bucket_lock);
 803
 804                 while (fifo_pop(&free, i))
 805                         atomic_dec(&ca->buckets[i].pin);
 806
 807                 free_fifo(&free);
 808         }
 809
 810         if (attr == &sysfs_clear_stats) {
 811                 atomic_long_set(&ca->sectors_written, 0);
 812                 atomic_long_set(&ca->btree_sectors_written, 0);
 813                 atomic_long_set(&ca->meta_sectors_written, 0);
 814                 atomic_set(&ca->io_count, 0);
 815                 atomic_set(&ca->io_errors, 0);
 816         }
 817
 818         return size;
 819 }
 820 STORE_LOCKED(bch_cache)
 821
 822 static struct attribute *bch_cache_files[] = {
 823         &sysfs_bucket_size,
 824         &sysfs_block_size,
 825         &sysfs_nbuckets,
 826         &sysfs_priority_stats,
 827         &sysfs_discard,
 828         &sysfs_written,
 829         &sysfs_btree_written,
 830         &sysfs_metadata_written,
 831         &sysfs_io_errors,
 832         &sysfs_clear_stats,
 833         &sysfs_freelist_percent,
 834         &sysfs_cache_replacement_policy,
 835         NULL
 836 };
 837 KTYPE(bch_cache);