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