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