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