1 /* 2 * Functions related to sysfs handling 3 */ 4 #include <linux/kernel.h> 5 #include <linux/module.h> 6 #include <linux/bio.h> 7 #include <linux/blkdev.h> 8 #include <linux/blktrace_api.h> 9 10 #include "blk.h" 11 12 struct queue_sysfs_entry { 13 struct attribute attr; 14 ssize_t (*show)(struct request_queue *, char *); 15 ssize_t (*store)(struct request_queue *, const char *, size_t); 16 }; 17 18 static ssize_t 19 queue_var_show(unsigned long var, char *page) 20 { 21 return sprintf(page, "%lu\n", var); 22 } 23 24 static ssize_t 25 queue_var_store(unsigned long *var, const char *page, size_t count) 26 { 27 char *p = (char *) page; 28 29 *var = simple_strtoul(p, &p, 10); 30 return count; 31 } 32 33 static ssize_t queue_requests_show(struct request_queue *q, char *page) 34 { 35 return queue_var_show(q->nr_requests, (page)); 36 } 37 38 static ssize_t 39 queue_requests_store(struct request_queue *q, const char *page, size_t count) 40 { 41 struct request_list *rl = &q->rq; 42 unsigned long nr; 43 int ret; 44 45 if (!q->request_fn) 46 return -EINVAL; 47 48 ret = queue_var_store(&nr, page, count); 49 if (nr < BLKDEV_MIN_RQ) 50 nr = BLKDEV_MIN_RQ; 51 52 spin_lock_irq(q->queue_lock); 53 q->nr_requests = nr; 54 blk_queue_congestion_threshold(q); 55 56 if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q)) 57 blk_set_queue_congested(q, BLK_RW_SYNC); 58 else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q)) 59 blk_clear_queue_congested(q, BLK_RW_SYNC); 60 61 if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q)) 62 blk_set_queue_congested(q, BLK_RW_ASYNC); 63 else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q)) 64 blk_clear_queue_congested(q, BLK_RW_ASYNC); 65 66 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) { 67 blk_set_queue_full(q, BLK_RW_SYNC); 68 } else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) { 69 blk_clear_queue_full(q, BLK_RW_SYNC); 70 wake_up(&rl->wait[BLK_RW_SYNC]); 71 } 72 73 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) { 74 blk_set_queue_full(q, BLK_RW_ASYNC); 75 } else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) { 76 blk_clear_queue_full(q, BLK_RW_ASYNC); 77 wake_up(&rl->wait[BLK_RW_ASYNC]); 78 } 79 spin_unlock_irq(q->queue_lock); 80 return ret; 81 } 82 83 static ssize_t queue_ra_show(struct request_queue *q, char *page) 84 { 85 unsigned long ra_kb = q->backing_dev_info.ra_pages << 86 (PAGE_CACHE_SHIFT - 10); 87 88 return queue_var_show(ra_kb, (page)); 89 } 90 91 static ssize_t 92 queue_ra_store(struct request_queue *q, const char *page, size_t count) 93 { 94 unsigned long ra_kb; 95 ssize_t ret = queue_var_store(&ra_kb, page, count); 96 97 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10); 98 99 return ret; 100 } 101 102 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) 103 { 104 int max_sectors_kb = queue_max_sectors(q) >> 1; 105 106 return queue_var_show(max_sectors_kb, (page)); 107 } 108 109 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) 110 { 111 return queue_var_show(queue_logical_block_size(q), page); 112 } 113 114 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page) 115 { 116 return queue_var_show(queue_physical_block_size(q), page); 117 } 118 119 static ssize_t queue_io_min_show(struct request_queue *q, char *page) 120 { 121 return queue_var_show(queue_io_min(q), page); 122 } 123 124 static ssize_t queue_io_opt_show(struct request_queue *q, char *page) 125 { 126 return queue_var_show(queue_io_opt(q), page); 127 } 128 129 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page) 130 { 131 return queue_var_show(q->limits.discard_granularity, page); 132 } 133 134 static ssize_t queue_discard_max_show(struct request_queue *q, char *page) 135 { 136 return queue_var_show(q->limits.max_discard_sectors << 9, page); 137 } 138 139 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) 140 { 141 return queue_var_show(queue_discard_zeroes_data(q), page); 142 } 143 144 static ssize_t 145 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) 146 { 147 unsigned long max_sectors_kb, 148 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1, 149 page_kb = 1 << (PAGE_CACHE_SHIFT - 10); 150 ssize_t ret = queue_var_store(&max_sectors_kb, page, count); 151 152 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) 153 return -EINVAL; 154 155 spin_lock_irq(q->queue_lock); 156 q->limits.max_sectors = max_sectors_kb << 1; 157 spin_unlock_irq(q->queue_lock); 158 159 return ret; 160 } 161 162 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) 163 { 164 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; 165 166 return queue_var_show(max_hw_sectors_kb, (page)); 167 } 168 169 static ssize_t queue_nonrot_show(struct request_queue *q, char *page) 170 { 171 return queue_var_show(!blk_queue_nonrot(q), page); 172 } 173 174 static ssize_t queue_nonrot_store(struct request_queue *q, const char *page, 175 size_t count) 176 { 177 unsigned long nm; 178 ssize_t ret = queue_var_store(&nm, page, count); 179 180 spin_lock_irq(q->queue_lock); 181 if (nm) 182 queue_flag_clear(QUEUE_FLAG_NONROT, q); 183 else 184 queue_flag_set(QUEUE_FLAG_NONROT, q); 185 spin_unlock_irq(q->queue_lock); 186 187 return ret; 188 } 189 190 static ssize_t queue_nomerges_show(struct request_queue *q, char *page) 191 { 192 return queue_var_show(blk_queue_nomerges(q), page); 193 } 194 195 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, 196 size_t count) 197 { 198 unsigned long nm; 199 ssize_t ret = queue_var_store(&nm, page, count); 200 201 spin_lock_irq(q->queue_lock); 202 if (nm) 203 queue_flag_set(QUEUE_FLAG_NOMERGES, q); 204 else 205 queue_flag_clear(QUEUE_FLAG_NOMERGES, q); 206 spin_unlock_irq(q->queue_lock); 207 208 return ret; 209 } 210 211 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) 212 { 213 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); 214 215 return queue_var_show(set, page); 216 } 217 218 static ssize_t 219 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) 220 { 221 ssize_t ret = -EINVAL; 222 #if defined(CONFIG_USE_GENERIC_SMP_HELPERS) 223 unsigned long val; 224 225 ret = queue_var_store(&val, page, count); 226 spin_lock_irq(q->queue_lock); 227 if (val) 228 queue_flag_set(QUEUE_FLAG_SAME_COMP, q); 229 else 230 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); 231 spin_unlock_irq(q->queue_lock); 232 #endif 233 return ret; 234 } 235 236 static ssize_t queue_iostats_show(struct request_queue *q, char *page) 237 { 238 return queue_var_show(blk_queue_io_stat(q), page); 239 } 240 241 static ssize_t queue_iostats_store(struct request_queue *q, const char *page, 242 size_t count) 243 { 244 unsigned long stats; 245 ssize_t ret = queue_var_store(&stats, page, count); 246 247 spin_lock_irq(q->queue_lock); 248 if (stats) 249 queue_flag_set(QUEUE_FLAG_IO_STAT, q); 250 else 251 queue_flag_clear(QUEUE_FLAG_IO_STAT, q); 252 spin_unlock_irq(q->queue_lock); 253 254 return ret; 255 } 256 257 static struct queue_sysfs_entry queue_requests_entry = { 258 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, 259 .show = queue_requests_show, 260 .store = queue_requests_store, 261 }; 262 263 static struct queue_sysfs_entry queue_ra_entry = { 264 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR }, 265 .show = queue_ra_show, 266 .store = queue_ra_store, 267 }; 268 269 static struct queue_sysfs_entry queue_max_sectors_entry = { 270 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR }, 271 .show = queue_max_sectors_show, 272 .store = queue_max_sectors_store, 273 }; 274 275 static struct queue_sysfs_entry queue_max_hw_sectors_entry = { 276 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO }, 277 .show = queue_max_hw_sectors_show, 278 }; 279 280 static struct queue_sysfs_entry queue_iosched_entry = { 281 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR }, 282 .show = elv_iosched_show, 283 .store = elv_iosched_store, 284 }; 285 286 static struct queue_sysfs_entry queue_hw_sector_size_entry = { 287 .attr = {.name = "hw_sector_size", .mode = S_IRUGO }, 288 .show = queue_logical_block_size_show, 289 }; 290 291 static struct queue_sysfs_entry queue_logical_block_size_entry = { 292 .attr = {.name = "logical_block_size", .mode = S_IRUGO }, 293 .show = queue_logical_block_size_show, 294 }; 295 296 static struct queue_sysfs_entry queue_physical_block_size_entry = { 297 .attr = {.name = "physical_block_size", .mode = S_IRUGO }, 298 .show = queue_physical_block_size_show, 299 }; 300 301 static struct queue_sysfs_entry queue_io_min_entry = { 302 .attr = {.name = "minimum_io_size", .mode = S_IRUGO }, 303 .show = queue_io_min_show, 304 }; 305 306 static struct queue_sysfs_entry queue_io_opt_entry = { 307 .attr = {.name = "optimal_io_size", .mode = S_IRUGO }, 308 .show = queue_io_opt_show, 309 }; 310 311 static struct queue_sysfs_entry queue_discard_granularity_entry = { 312 .attr = {.name = "discard_granularity", .mode = S_IRUGO }, 313 .show = queue_discard_granularity_show, 314 }; 315 316 static struct queue_sysfs_entry queue_discard_max_entry = { 317 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO }, 318 .show = queue_discard_max_show, 319 }; 320 321 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = { 322 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO }, 323 .show = queue_discard_zeroes_data_show, 324 }; 325 326 static struct queue_sysfs_entry queue_nonrot_entry = { 327 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR }, 328 .show = queue_nonrot_show, 329 .store = queue_nonrot_store, 330 }; 331 332 static struct queue_sysfs_entry queue_nomerges_entry = { 333 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR }, 334 .show = queue_nomerges_show, 335 .store = queue_nomerges_store, 336 }; 337 338 static struct queue_sysfs_entry queue_rq_affinity_entry = { 339 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR }, 340 .show = queue_rq_affinity_show, 341 .store = queue_rq_affinity_store, 342 }; 343 344 static struct queue_sysfs_entry queue_iostats_entry = { 345 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR }, 346 .show = queue_iostats_show, 347 .store = queue_iostats_store, 348 }; 349 350 static struct attribute *default_attrs[] = { 351 &queue_requests_entry.attr, 352 &queue_ra_entry.attr, 353 &queue_max_hw_sectors_entry.attr, 354 &queue_max_sectors_entry.attr, 355 &queue_iosched_entry.attr, 356 &queue_hw_sector_size_entry.attr, 357 &queue_logical_block_size_entry.attr, 358 &queue_physical_block_size_entry.attr, 359 &queue_io_min_entry.attr, 360 &queue_io_opt_entry.attr, 361 &queue_discard_granularity_entry.attr, 362 &queue_discard_max_entry.attr, 363 &queue_discard_zeroes_data_entry.attr, 364 &queue_nonrot_entry.attr, 365 &queue_nomerges_entry.attr, 366 &queue_rq_affinity_entry.attr, 367 &queue_iostats_entry.attr, 368 NULL, 369 }; 370 371 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) 372 373 static ssize_t 374 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) 375 { 376 struct queue_sysfs_entry *entry = to_queue(attr); 377 struct request_queue *q = 378 container_of(kobj, struct request_queue, kobj); 379 ssize_t res; 380 381 if (!entry->show) 382 return -EIO; 383 mutex_lock(&q->sysfs_lock); 384 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) { 385 mutex_unlock(&q->sysfs_lock); 386 return -ENOENT; 387 } 388 res = entry->show(q, page); 389 mutex_unlock(&q->sysfs_lock); 390 return res; 391 } 392 393 static ssize_t 394 queue_attr_store(struct kobject *kobj, struct attribute *attr, 395 const char *page, size_t length) 396 { 397 struct queue_sysfs_entry *entry = to_queue(attr); 398 struct request_queue *q; 399 ssize_t res; 400 401 if (!entry->store) 402 return -EIO; 403 404 q = container_of(kobj, struct request_queue, kobj); 405 mutex_lock(&q->sysfs_lock); 406 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) { 407 mutex_unlock(&q->sysfs_lock); 408 return -ENOENT; 409 } 410 res = entry->store(q, page, length); 411 mutex_unlock(&q->sysfs_lock); 412 return res; 413 } 414 415 /** 416 * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed 417 * @kobj: the kobj belonging of the request queue to be released 418 * 419 * Description: 420 * blk_cleanup_queue is the pair to blk_init_queue() or 421 * blk_queue_make_request(). It should be called when a request queue is 422 * being released; typically when a block device is being de-registered. 423 * Currently, its primary task it to free all the &struct request 424 * structures that were allocated to the queue and the queue itself. 425 * 426 * Caveat: 427 * Hopefully the low level driver will have finished any 428 * outstanding requests first... 429 **/ 430 static void blk_release_queue(struct kobject *kobj) 431 { 432 struct request_queue *q = 433 container_of(kobj, struct request_queue, kobj); 434 struct request_list *rl = &q->rq; 435 436 blk_sync_queue(q); 437 438 if (rl->rq_pool) 439 mempool_destroy(rl->rq_pool); 440 441 if (q->queue_tags) 442 __blk_queue_free_tags(q); 443 444 blk_trace_shutdown(q); 445 446 bdi_destroy(&q->backing_dev_info); 447 kmem_cache_free(blk_requestq_cachep, q); 448 } 449 450 static struct sysfs_ops queue_sysfs_ops = { 451 .show = queue_attr_show, 452 .store = queue_attr_store, 453 }; 454 455 struct kobj_type blk_queue_ktype = { 456 .sysfs_ops = &queue_sysfs_ops, 457 .default_attrs = default_attrs, 458 .release = blk_release_queue, 459 }; 460 461 int blk_register_queue(struct gendisk *disk) 462 { 463 int ret; 464 struct device *dev = disk_to_dev(disk); 465 466 struct request_queue *q = disk->queue; 467 468 if (WARN_ON(!q)) 469 return -ENXIO; 470 471 ret = blk_trace_init_sysfs(dev); 472 if (ret) 473 return ret; 474 475 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); 476 if (ret < 0) 477 return ret; 478 479 kobject_uevent(&q->kobj, KOBJ_ADD); 480 481 if (!q->request_fn) 482 return 0; 483 484 ret = elv_register_queue(q); 485 if (ret) { 486 kobject_uevent(&q->kobj, KOBJ_REMOVE); 487 kobject_del(&q->kobj); 488 blk_trace_remove_sysfs(disk_to_dev(disk)); 489 return ret; 490 } 491 492 return 0; 493 } 494 495 void blk_unregister_queue(struct gendisk *disk) 496 { 497 struct request_queue *q = disk->queue; 498 499 if (WARN_ON(!q)) 500 return; 501 502 if (q->request_fn) 503 elv_unregister_queue(q); 504 505 kobject_uevent(&q->kobj, KOBJ_REMOVE); 506 kobject_del(&q->kobj); 507 blk_trace_remove_sysfs(disk_to_dev(disk)); 508 kobject_put(&disk_to_dev(disk)->kobj); 509 } 510