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