1 /* 2 * Functions related to sysfs handling 3 */ 4 #include <linux/kernel.h> 5 #include <linux/slab.h> 6 #include <linux/module.h> 7 #include <linux/bio.h> 8 #include <linux/blkdev.h> 9 #include <linux/blktrace_api.h> 10 11 #include "blk.h" 12 #include "blk-cgroup.h" 13 14 struct queue_sysfs_entry { 15 struct attribute attr; 16 ssize_t (*show)(struct request_queue *, char *); 17 ssize_t (*store)(struct request_queue *, const char *, size_t); 18 }; 19 20 static ssize_t 21 queue_var_show(unsigned long var, char *page) 22 { 23 return sprintf(page, "%lu\n", var); 24 } 25 26 static ssize_t 27 queue_var_store(unsigned long *var, const char *page, size_t count) 28 { 29 char *p = (char *) page; 30 31 *var = simple_strtoul(p, &p, 10); 32 return count; 33 } 34 35 static ssize_t queue_requests_show(struct request_queue *q, char *page) 36 { 37 return queue_var_show(q->nr_requests, (page)); 38 } 39 40 static ssize_t 41 queue_requests_store(struct request_queue *q, const char *page, size_t count) 42 { 43 struct request_list *rl; 44 unsigned long nr; 45 int ret; 46 47 if (!q->request_fn) 48 return -EINVAL; 49 50 ret = queue_var_store(&nr, page, count); 51 if (nr < BLKDEV_MIN_RQ) 52 nr = BLKDEV_MIN_RQ; 53 54 spin_lock_irq(q->queue_lock); 55 q->nr_requests = nr; 56 blk_queue_congestion_threshold(q); 57 58 /* congestion isn't cgroup aware and follows root blkcg for now */ 59 rl = &q->root_rl; 60 61 if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q)) 62 blk_set_queue_congested(q, BLK_RW_SYNC); 63 else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q)) 64 blk_clear_queue_congested(q, BLK_RW_SYNC); 65 66 if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q)) 67 blk_set_queue_congested(q, BLK_RW_ASYNC); 68 else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q)) 69 blk_clear_queue_congested(q, BLK_RW_ASYNC); 70 71 blk_queue_for_each_rl(rl, q) { 72 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) { 73 blk_set_rl_full(rl, BLK_RW_SYNC); 74 } else { 75 blk_clear_rl_full(rl, BLK_RW_SYNC); 76 wake_up(&rl->wait[BLK_RW_SYNC]); 77 } 78 79 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) { 80 blk_set_rl_full(rl, BLK_RW_ASYNC); 81 } else { 82 blk_clear_rl_full(rl, BLK_RW_ASYNC); 83 wake_up(&rl->wait[BLK_RW_ASYNC]); 84 } 85 } 86 87 spin_unlock_irq(q->queue_lock); 88 return ret; 89 } 90 91 static ssize_t queue_ra_show(struct request_queue *q, char *page) 92 { 93 unsigned long ra_kb = q->backing_dev_info.ra_pages << 94 (PAGE_CACHE_SHIFT - 10); 95 96 return queue_var_show(ra_kb, (page)); 97 } 98 99 static ssize_t 100 queue_ra_store(struct request_queue *q, const char *page, size_t count) 101 { 102 unsigned long ra_kb; 103 ssize_t ret = queue_var_store(&ra_kb, page, count); 104 105 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10); 106 107 return ret; 108 } 109 110 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) 111 { 112 int max_sectors_kb = queue_max_sectors(q) >> 1; 113 114 return queue_var_show(max_sectors_kb, (page)); 115 } 116 117 static ssize_t queue_max_segments_show(struct request_queue *q, char *page) 118 { 119 return queue_var_show(queue_max_segments(q), (page)); 120 } 121 122 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) 123 { 124 return queue_var_show(q->limits.max_integrity_segments, (page)); 125 } 126 127 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) 128 { 129 if (blk_queue_cluster(q)) 130 return queue_var_show(queue_max_segment_size(q), (page)); 131 132 return queue_var_show(PAGE_CACHE_SIZE, (page)); 133 } 134 135 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) 136 { 137 return queue_var_show(queue_logical_block_size(q), page); 138 } 139 140 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page) 141 { 142 return queue_var_show(queue_physical_block_size(q), page); 143 } 144 145 static ssize_t queue_io_min_show(struct request_queue *q, char *page) 146 { 147 return queue_var_show(queue_io_min(q), page); 148 } 149 150 static ssize_t queue_io_opt_show(struct request_queue *q, char *page) 151 { 152 return queue_var_show(queue_io_opt(q), page); 153 } 154 155 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page) 156 { 157 return queue_var_show(q->limits.discard_granularity, page); 158 } 159 160 static ssize_t queue_discard_max_show(struct request_queue *q, char *page) 161 { 162 return sprintf(page, "%llu\n", 163 (unsigned long long)q->limits.max_discard_sectors << 9); 164 } 165 166 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) 167 { 168 return queue_var_show(queue_discard_zeroes_data(q), page); 169 } 170 171 static ssize_t 172 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) 173 { 174 unsigned long max_sectors_kb, 175 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1, 176 page_kb = 1 << (PAGE_CACHE_SHIFT - 10); 177 ssize_t ret = queue_var_store(&max_sectors_kb, page, count); 178 179 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) 180 return -EINVAL; 181 182 spin_lock_irq(q->queue_lock); 183 q->limits.max_sectors = max_sectors_kb << 1; 184 spin_unlock_irq(q->queue_lock); 185 186 return ret; 187 } 188 189 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) 190 { 191 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; 192 193 return queue_var_show(max_hw_sectors_kb, (page)); 194 } 195 196 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ 197 static ssize_t \ 198 queue_show_##name(struct request_queue *q, char *page) \ 199 { \ 200 int bit; \ 201 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ 202 return queue_var_show(neg ? !bit : bit, page); \ 203 } \ 204 static ssize_t \ 205 queue_store_##name(struct request_queue *q, const char *page, size_t count) \ 206 { \ 207 unsigned long val; \ 208 ssize_t ret; \ 209 ret = queue_var_store(&val, page, count); \ 210 if (neg) \ 211 val = !val; \ 212 \ 213 spin_lock_irq(q->queue_lock); \ 214 if (val) \ 215 queue_flag_set(QUEUE_FLAG_##flag, q); \ 216 else \ 217 queue_flag_clear(QUEUE_FLAG_##flag, q); \ 218 spin_unlock_irq(q->queue_lock); \ 219 return ret; \ 220 } 221 222 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); 223 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); 224 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); 225 #undef QUEUE_SYSFS_BIT_FNS 226 227 static ssize_t queue_nomerges_show(struct request_queue *q, char *page) 228 { 229 return queue_var_show((blk_queue_nomerges(q) << 1) | 230 blk_queue_noxmerges(q), page); 231 } 232 233 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, 234 size_t count) 235 { 236 unsigned long nm; 237 ssize_t ret = queue_var_store(&nm, page, count); 238 239 spin_lock_irq(q->queue_lock); 240 queue_flag_clear(QUEUE_FLAG_NOMERGES, q); 241 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); 242 if (nm == 2) 243 queue_flag_set(QUEUE_FLAG_NOMERGES, q); 244 else if (nm) 245 queue_flag_set(QUEUE_FLAG_NOXMERGES, q); 246 spin_unlock_irq(q->queue_lock); 247 248 return ret; 249 } 250 251 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) 252 { 253 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); 254 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); 255 256 return queue_var_show(set << force, page); 257 } 258 259 static ssize_t 260 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) 261 { 262 ssize_t ret = -EINVAL; 263 #if defined(CONFIG_USE_GENERIC_SMP_HELPERS) 264 unsigned long val; 265 266 ret = queue_var_store(&val, page, count); 267 spin_lock_irq(q->queue_lock); 268 if (val == 2) { 269 queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 270 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); 271 } else if (val == 1) { 272 queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 273 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 274 } else if (val == 0) { 275 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); 276 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); 277 } 278 spin_unlock_irq(q->queue_lock); 279 #endif 280 return ret; 281 } 282 283 static struct queue_sysfs_entry queue_requests_entry = { 284 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, 285 .show = queue_requests_show, 286 .store = queue_requests_store, 287 }; 288 289 static struct queue_sysfs_entry queue_ra_entry = { 290 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR }, 291 .show = queue_ra_show, 292 .store = queue_ra_store, 293 }; 294 295 static struct queue_sysfs_entry queue_max_sectors_entry = { 296 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR }, 297 .show = queue_max_sectors_show, 298 .store = queue_max_sectors_store, 299 }; 300 301 static struct queue_sysfs_entry queue_max_hw_sectors_entry = { 302 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO }, 303 .show = queue_max_hw_sectors_show, 304 }; 305 306 static struct queue_sysfs_entry queue_max_segments_entry = { 307 .attr = {.name = "max_segments", .mode = S_IRUGO }, 308 .show = queue_max_segments_show, 309 }; 310 311 static struct queue_sysfs_entry queue_max_integrity_segments_entry = { 312 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO }, 313 .show = queue_max_integrity_segments_show, 314 }; 315 316 static struct queue_sysfs_entry queue_max_segment_size_entry = { 317 .attr = {.name = "max_segment_size", .mode = S_IRUGO }, 318 .show = queue_max_segment_size_show, 319 }; 320 321 static struct queue_sysfs_entry queue_iosched_entry = { 322 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR }, 323 .show = elv_iosched_show, 324 .store = elv_iosched_store, 325 }; 326 327 static struct queue_sysfs_entry queue_hw_sector_size_entry = { 328 .attr = {.name = "hw_sector_size", .mode = S_IRUGO }, 329 .show = queue_logical_block_size_show, 330 }; 331 332 static struct queue_sysfs_entry queue_logical_block_size_entry = { 333 .attr = {.name = "logical_block_size", .mode = S_IRUGO }, 334 .show = queue_logical_block_size_show, 335 }; 336 337 static struct queue_sysfs_entry queue_physical_block_size_entry = { 338 .attr = {.name = "physical_block_size", .mode = S_IRUGO }, 339 .show = queue_physical_block_size_show, 340 }; 341 342 static struct queue_sysfs_entry queue_io_min_entry = { 343 .attr = {.name = "minimum_io_size", .mode = S_IRUGO }, 344 .show = queue_io_min_show, 345 }; 346 347 static struct queue_sysfs_entry queue_io_opt_entry = { 348 .attr = {.name = "optimal_io_size", .mode = S_IRUGO }, 349 .show = queue_io_opt_show, 350 }; 351 352 static struct queue_sysfs_entry queue_discard_granularity_entry = { 353 .attr = {.name = "discard_granularity", .mode = S_IRUGO }, 354 .show = queue_discard_granularity_show, 355 }; 356 357 static struct queue_sysfs_entry queue_discard_max_entry = { 358 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO }, 359 .show = queue_discard_max_show, 360 }; 361 362 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = { 363 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO }, 364 .show = queue_discard_zeroes_data_show, 365 }; 366 367 static struct queue_sysfs_entry queue_nonrot_entry = { 368 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR }, 369 .show = queue_show_nonrot, 370 .store = queue_store_nonrot, 371 }; 372 373 static struct queue_sysfs_entry queue_nomerges_entry = { 374 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR }, 375 .show = queue_nomerges_show, 376 .store = queue_nomerges_store, 377 }; 378 379 static struct queue_sysfs_entry queue_rq_affinity_entry = { 380 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR }, 381 .show = queue_rq_affinity_show, 382 .store = queue_rq_affinity_store, 383 }; 384 385 static struct queue_sysfs_entry queue_iostats_entry = { 386 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR }, 387 .show = queue_show_iostats, 388 .store = queue_store_iostats, 389 }; 390 391 static struct queue_sysfs_entry queue_random_entry = { 392 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR }, 393 .show = queue_show_random, 394 .store = queue_store_random, 395 }; 396 397 static struct attribute *default_attrs[] = { 398 &queue_requests_entry.attr, 399 &queue_ra_entry.attr, 400 &queue_max_hw_sectors_entry.attr, 401 &queue_max_sectors_entry.attr, 402 &queue_max_segments_entry.attr, 403 &queue_max_integrity_segments_entry.attr, 404 &queue_max_segment_size_entry.attr, 405 &queue_iosched_entry.attr, 406 &queue_hw_sector_size_entry.attr, 407 &queue_logical_block_size_entry.attr, 408 &queue_physical_block_size_entry.attr, 409 &queue_io_min_entry.attr, 410 &queue_io_opt_entry.attr, 411 &queue_discard_granularity_entry.attr, 412 &queue_discard_max_entry.attr, 413 &queue_discard_zeroes_data_entry.attr, 414 &queue_nonrot_entry.attr, 415 &queue_nomerges_entry.attr, 416 &queue_rq_affinity_entry.attr, 417 &queue_iostats_entry.attr, 418 &queue_random_entry.attr, 419 NULL, 420 }; 421 422 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) 423 424 static ssize_t 425 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 426 { 427 struct queue_sysfs_entry *entry = to_queue(attr); 428 struct request_queue *q = 429 container_of(kobj, struct request_queue, kobj); 430 ssize_t res; 431 432 if (!entry->show) 433 return -EIO; 434 mutex_lock(&q->sysfs_lock); 435 if (blk_queue_dead(q)) { 436 mutex_unlock(&q->sysfs_lock); 437 return -ENOENT; 438 } 439 res = entry->show(q, page); 440 mutex_unlock(&q->sysfs_lock); 441 return res; 442 } 443 444 static ssize_t 445 queue_attr_store(struct kobject *kobj, struct attribute *attr, 446 const char *page, size_t length) 447 { 448 struct queue_sysfs_entry *entry = to_queue(attr); 449 struct request_queue *q; 450 ssize_t res; 451 452 if (!entry->store) 453 return -EIO; 454 455 q = container_of(kobj, struct request_queue, kobj); 456 mutex_lock(&q->sysfs_lock); 457 if (blk_queue_dead(q)) { 458 mutex_unlock(&q->sysfs_lock); 459 return -ENOENT; 460 } 461 res = entry->store(q, page, length); 462 mutex_unlock(&q->sysfs_lock); 463 return res; 464 } 465 466 /** 467 * blk_release_queue: - release a &struct request_queue when it is no longer needed 468 * @kobj: the kobj belonging to the request queue to be released 469 * 470 * Description: 471 * blk_release_queue is the pair to blk_init_queue() or 472 * blk_queue_make_request(). It should be called when a request queue is 473 * being released; typically when a block device is being de-registered. 474 * Currently, its primary task it to free all the &struct request 475 * structures that were allocated to the queue and the queue itself. 476 * 477 * Caveat: 478 * Hopefully the low level driver will have finished any 479 * outstanding requests first... 480 **/ 481 static void blk_release_queue(struct kobject *kobj) 482 { 483 struct request_queue *q = 484 container_of(kobj, struct request_queue, kobj); 485 486 blk_sync_queue(q); 487 488 blkcg_exit_queue(q); 489 490 if (q->elevator) { 491 spin_lock_irq(q->queue_lock); 492 ioc_clear_queue(q); 493 spin_unlock_irq(q->queue_lock); 494 elevator_exit(q->elevator); 495 } 496 497 blk_exit_rl(&q->root_rl); 498 499 if (q->queue_tags) 500 __blk_queue_free_tags(q); 501 502 blk_trace_shutdown(q); 503 504 bdi_destroy(&q->backing_dev_info); 505 506 ida_simple_remove(&blk_queue_ida, q->id); 507 kmem_cache_free(blk_requestq_cachep, q); 508 } 509 510 static const struct sysfs_ops queue_sysfs_ops = { 511 .show = queue_attr_show, 512 .store = queue_attr_store, 513 }; 514 515 struct kobj_type blk_queue_ktype = { 516 .sysfs_ops = &queue_sysfs_ops, 517 .default_attrs = default_attrs, 518 .release = blk_release_queue, 519 }; 520 521 int blk_register_queue(struct gendisk *disk) 522 { 523 int ret; 524 struct device *dev = disk_to_dev(disk); 525 struct request_queue *q = disk->queue; 526 527 if (WARN_ON(!q)) 528 return -ENXIO; 529 530 ret = blk_trace_init_sysfs(dev); 531 if (ret) 532 return ret; 533 534 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); 535 if (ret < 0) { 536 blk_trace_remove_sysfs(dev); 537 return ret; 538 } 539 540 kobject_uevent(&q->kobj, KOBJ_ADD); 541 542 if (!q->request_fn) 543 return 0; 544 545 ret = elv_register_queue(q); 546 if (ret) { 547 kobject_uevent(&q->kobj, KOBJ_REMOVE); 548 kobject_del(&q->kobj); 549 blk_trace_remove_sysfs(dev); 550 kobject_put(&dev->kobj); 551 return ret; 552 } 553 554 return 0; 555 } 556 557 void blk_unregister_queue(struct gendisk *disk) 558 { 559 struct request_queue *q = disk->queue; 560 561 if (WARN_ON(!q)) 562 return; 563 564 if (q->request_fn) 565 elv_unregister_queue(q); 566 567 kobject_uevent(&q->kobj, KOBJ_REMOVE); 568 kobject_del(&q->kobj); 569 blk_trace_remove_sysfs(disk_to_dev(disk)); 570 kobject_put(&disk_to_dev(disk)->kobj); 571 } 572