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