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