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