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