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