drivers/md/bcache/sysfs.c

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