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