| 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/backing-dev.h> |
| 10 | #include <linux/blktrace_api.h> |
| 11 | #include <linux/blk-mq.h> |
| 12 | #include <linux/blk-cgroup.h> |
| 13 | |
| 14 | #include "blk.h" |
| 15 | #include "blk-mq.h" |
| 16 | |
| 17 | struct queue_sysfs_entry { |
| 18 | struct attribute attr; |
| 19 | ssize_t (*show)(struct request_queue *, char *); |
| 20 | ssize_t (*store)(struct request_queue *, const char *, size_t); |
| 21 | }; |
| 22 | |
| 23 | static ssize_t |
| 24 | queue_var_show(unsigned long var, char *page) |
| 25 | { |
| 26 | return sprintf(page, "%lu\n", var); |
| 27 | } |
| 28 | |
| 29 | static ssize_t |
| 30 | queue_var_store(unsigned long *var, const char *page, size_t count) |
| 31 | { |
| 32 | int err; |
| 33 | unsigned long v; |
| 34 | |
| 35 | err = kstrtoul(page, 10, &v); |
| 36 | if (err || v > UINT_MAX) |
| 37 | return -EINVAL; |
| 38 | |
| 39 | *var = v; |
| 40 | |
| 41 | return count; |
| 42 | } |
| 43 | |
| 44 | static ssize_t queue_requests_show(struct request_queue *q, char *page) |
| 45 | { |
| 46 | return queue_var_show(q->nr_requests, (page)); |
| 47 | } |
| 48 | |
| 49 | static ssize_t |
| 50 | queue_requests_store(struct request_queue *q, const char *page, size_t count) |
| 51 | { |
| 52 | unsigned long nr; |
| 53 | int ret, err; |
| 54 | |
| 55 | if (!q->request_fn && !q->mq_ops) |
| 56 | return -EINVAL; |
| 57 | |
| 58 | ret = queue_var_store(&nr, page, count); |
| 59 | if (ret < 0) |
| 60 | return ret; |
| 61 | |
| 62 | if (nr < BLKDEV_MIN_RQ) |
| 63 | nr = BLKDEV_MIN_RQ; |
| 64 | |
| 65 | if (q->request_fn) |
| 66 | err = blk_update_nr_requests(q, nr); |
| 67 | else |
| 68 | err = blk_mq_update_nr_requests(q, nr); |
| 69 | |
| 70 | if (err) |
| 71 | return err; |
| 72 | |
| 73 | return ret; |
| 74 | } |
| 75 | |
| 76 | static ssize_t queue_ra_show(struct request_queue *q, char *page) |
| 77 | { |
| 78 | unsigned long ra_kb = q->backing_dev_info.ra_pages << |
| 79 | (PAGE_SHIFT - 10); |
| 80 | |
| 81 | return queue_var_show(ra_kb, (page)); |
| 82 | } |
| 83 | |
| 84 | static ssize_t |
| 85 | queue_ra_store(struct request_queue *q, const char *page, size_t count) |
| 86 | { |
| 87 | unsigned long ra_kb; |
| 88 | ssize_t ret = queue_var_store(&ra_kb, page, count); |
| 89 | |
| 90 | if (ret < 0) |
| 91 | return ret; |
| 92 | |
| 93 | q->backing_dev_info.ra_pages = ra_kb >> (PAGE_SHIFT - 10); |
| 94 | |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) |
| 99 | { |
| 100 | int max_sectors_kb = queue_max_sectors(q) >> 1; |
| 101 | |
| 102 | return queue_var_show(max_sectors_kb, (page)); |
| 103 | } |
| 104 | |
| 105 | static ssize_t queue_max_segments_show(struct request_queue *q, char *page) |
| 106 | { |
| 107 | return queue_var_show(queue_max_segments(q), (page)); |
| 108 | } |
| 109 | |
| 110 | static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) |
| 111 | { |
| 112 | return queue_var_show(q->limits.max_integrity_segments, (page)); |
| 113 | } |
| 114 | |
| 115 | static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) |
| 116 | { |
| 117 | if (blk_queue_cluster(q)) |
| 118 | return queue_var_show(queue_max_segment_size(q), (page)); |
| 119 | |
| 120 | return queue_var_show(PAGE_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_hw_show(struct request_queue *q, char *page) |
| 149 | { |
| 150 | |
| 151 | return sprintf(page, "%llu\n", |
| 152 | (unsigned long long)q->limits.max_hw_discard_sectors << 9); |
| 153 | } |
| 154 | |
| 155 | static ssize_t queue_discard_max_show(struct request_queue *q, char *page) |
| 156 | { |
| 157 | return sprintf(page, "%llu\n", |
| 158 | (unsigned long long)q->limits.max_discard_sectors << 9); |
| 159 | } |
| 160 | |
| 161 | static ssize_t queue_discard_max_store(struct request_queue *q, |
| 162 | const char *page, size_t count) |
| 163 | { |
| 164 | unsigned long max_discard; |
| 165 | ssize_t ret = queue_var_store(&max_discard, page, count); |
| 166 | |
| 167 | if (ret < 0) |
| 168 | return ret; |
| 169 | |
| 170 | if (max_discard & (q->limits.discard_granularity - 1)) |
| 171 | return -EINVAL; |
| 172 | |
| 173 | max_discard >>= 9; |
| 174 | if (max_discard > UINT_MAX) |
| 175 | return -EINVAL; |
| 176 | |
| 177 | if (max_discard > q->limits.max_hw_discard_sectors) |
| 178 | max_discard = q->limits.max_hw_discard_sectors; |
| 179 | |
| 180 | q->limits.max_discard_sectors = max_discard; |
| 181 | return ret; |
| 182 | } |
| 183 | |
| 184 | static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) |
| 185 | { |
| 186 | return queue_var_show(queue_discard_zeroes_data(q), page); |
| 187 | } |
| 188 | |
| 189 | static ssize_t queue_write_same_max_show(struct request_queue *q, char *page) |
| 190 | { |
| 191 | return sprintf(page, "%llu\n", |
| 192 | (unsigned long long)q->limits.max_write_same_sectors << 9); |
| 193 | } |
| 194 | |
| 195 | |
| 196 | static ssize_t |
| 197 | queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) |
| 198 | { |
| 199 | unsigned long max_sectors_kb, |
| 200 | max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1, |
| 201 | page_kb = 1 << (PAGE_SHIFT - 10); |
| 202 | ssize_t ret = queue_var_store(&max_sectors_kb, page, count); |
| 203 | |
| 204 | if (ret < 0) |
| 205 | return ret; |
| 206 | |
| 207 | max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long) |
| 208 | q->limits.max_dev_sectors >> 1); |
| 209 | |
| 210 | if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) |
| 211 | return -EINVAL; |
| 212 | |
| 213 | spin_lock_irq(q->queue_lock); |
| 214 | q->limits.max_sectors = max_sectors_kb << 1; |
| 215 | spin_unlock_irq(q->queue_lock); |
| 216 | |
| 217 | return ret; |
| 218 | } |
| 219 | |
| 220 | static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) |
| 221 | { |
| 222 | int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; |
| 223 | |
| 224 | return queue_var_show(max_hw_sectors_kb, (page)); |
| 225 | } |
| 226 | |
| 227 | #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ |
| 228 | static ssize_t \ |
| 229 | queue_show_##name(struct request_queue *q, char *page) \ |
| 230 | { \ |
| 231 | int bit; \ |
| 232 | bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ |
| 233 | return queue_var_show(neg ? !bit : bit, page); \ |
| 234 | } \ |
| 235 | static ssize_t \ |
| 236 | queue_store_##name(struct request_queue *q, const char *page, size_t count) \ |
| 237 | { \ |
| 238 | unsigned long val; \ |
| 239 | ssize_t ret; \ |
| 240 | ret = queue_var_store(&val, page, count); \ |
| 241 | if (ret < 0) \ |
| 242 | return ret; \ |
| 243 | if (neg) \ |
| 244 | val = !val; \ |
| 245 | \ |
| 246 | spin_lock_irq(q->queue_lock); \ |
| 247 | if (val) \ |
| 248 | queue_flag_set(QUEUE_FLAG_##flag, q); \ |
| 249 | else \ |
| 250 | queue_flag_clear(QUEUE_FLAG_##flag, q); \ |
| 251 | spin_unlock_irq(q->queue_lock); \ |
| 252 | return ret; \ |
| 253 | } |
| 254 | |
| 255 | QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); |
| 256 | QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); |
| 257 | QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); |
| 258 | #undef QUEUE_SYSFS_BIT_FNS |
| 259 | |
| 260 | static ssize_t queue_nomerges_show(struct request_queue *q, char *page) |
| 261 | { |
| 262 | return queue_var_show((blk_queue_nomerges(q) << 1) | |
| 263 | blk_queue_noxmerges(q), page); |
| 264 | } |
| 265 | |
| 266 | static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, |
| 267 | size_t count) |
| 268 | { |
| 269 | unsigned long nm; |
| 270 | ssize_t ret = queue_var_store(&nm, page, count); |
| 271 | |
| 272 | if (ret < 0) |
| 273 | return ret; |
| 274 | |
| 275 | spin_lock_irq(q->queue_lock); |
| 276 | queue_flag_clear(QUEUE_FLAG_NOMERGES, q); |
| 277 | queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); |
| 278 | if (nm == 2) |
| 279 | queue_flag_set(QUEUE_FLAG_NOMERGES, q); |
| 280 | else if (nm) |
| 281 | queue_flag_set(QUEUE_FLAG_NOXMERGES, q); |
| 282 | spin_unlock_irq(q->queue_lock); |
| 283 | |
| 284 | return ret; |
| 285 | } |
| 286 | |
| 287 | static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) |
| 288 | { |
| 289 | bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); |
| 290 | bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); |
| 291 | |
| 292 | return queue_var_show(set << force, page); |
| 293 | } |
| 294 | |
| 295 | static ssize_t |
| 296 | queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) |
| 297 | { |
| 298 | ssize_t ret = -EINVAL; |
| 299 | #ifdef CONFIG_SMP |
| 300 | unsigned long val; |
| 301 | |
| 302 | ret = queue_var_store(&val, page, count); |
| 303 | if (ret < 0) |
| 304 | return ret; |
| 305 | |
| 306 | spin_lock_irq(q->queue_lock); |
| 307 | if (val == 2) { |
| 308 | queue_flag_set(QUEUE_FLAG_SAME_COMP, q); |
| 309 | queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); |
| 310 | } else if (val == 1) { |
| 311 | queue_flag_set(QUEUE_FLAG_SAME_COMP, q); |
| 312 | queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); |
| 313 | } else if (val == 0) { |
| 314 | queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); |
| 315 | queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); |
| 316 | } |
| 317 | spin_unlock_irq(q->queue_lock); |
| 318 | #endif |
| 319 | return ret; |
| 320 | } |
| 321 | |
| 322 | static ssize_t queue_poll_show(struct request_queue *q, char *page) |
| 323 | { |
| 324 | return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); |
| 325 | } |
| 326 | |
| 327 | static ssize_t queue_poll_store(struct request_queue *q, const char *page, |
| 328 | size_t count) |
| 329 | { |
| 330 | unsigned long poll_on; |
| 331 | ssize_t ret; |
| 332 | |
| 333 | if (!q->mq_ops || !q->mq_ops->poll) |
| 334 | return -EINVAL; |
| 335 | |
| 336 | ret = queue_var_store(&poll_on, page, count); |
| 337 | if (ret < 0) |
| 338 | return ret; |
| 339 | |
| 340 | spin_lock_irq(q->queue_lock); |
| 341 | if (poll_on) |
| 342 | queue_flag_set(QUEUE_FLAG_POLL, q); |
| 343 | else |
| 344 | queue_flag_clear(QUEUE_FLAG_POLL, q); |
| 345 | spin_unlock_irq(q->queue_lock); |
| 346 | |
| 347 | return ret; |
| 348 | } |
| 349 | |
| 350 | static struct queue_sysfs_entry queue_requests_entry = { |
| 351 | .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, |
| 352 | .show = queue_requests_show, |
| 353 | .store = queue_requests_store, |
| 354 | }; |
| 355 | |
| 356 | static struct queue_sysfs_entry queue_ra_entry = { |
| 357 | .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR }, |
| 358 | .show = queue_ra_show, |
| 359 | .store = queue_ra_store, |
| 360 | }; |
| 361 | |
| 362 | static struct queue_sysfs_entry queue_max_sectors_entry = { |
| 363 | .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR }, |
| 364 | .show = queue_max_sectors_show, |
| 365 | .store = queue_max_sectors_store, |
| 366 | }; |
| 367 | |
| 368 | static struct queue_sysfs_entry queue_max_hw_sectors_entry = { |
| 369 | .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO }, |
| 370 | .show = queue_max_hw_sectors_show, |
| 371 | }; |
| 372 | |
| 373 | static struct queue_sysfs_entry queue_max_segments_entry = { |
| 374 | .attr = {.name = "max_segments", .mode = S_IRUGO }, |
| 375 | .show = queue_max_segments_show, |
| 376 | }; |
| 377 | |
| 378 | static struct queue_sysfs_entry queue_max_integrity_segments_entry = { |
| 379 | .attr = {.name = "max_integrity_segments", .mode = S_IRUGO }, |
| 380 | .show = queue_max_integrity_segments_show, |
| 381 | }; |
| 382 | |
| 383 | static struct queue_sysfs_entry queue_max_segment_size_entry = { |
| 384 | .attr = {.name = "max_segment_size", .mode = S_IRUGO }, |
| 385 | .show = queue_max_segment_size_show, |
| 386 | }; |
| 387 | |
| 388 | static struct queue_sysfs_entry queue_iosched_entry = { |
| 389 | .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR }, |
| 390 | .show = elv_iosched_show, |
| 391 | .store = elv_iosched_store, |
| 392 | }; |
| 393 | |
| 394 | static struct queue_sysfs_entry queue_hw_sector_size_entry = { |
| 395 | .attr = {.name = "hw_sector_size", .mode = S_IRUGO }, |
| 396 | .show = queue_logical_block_size_show, |
| 397 | }; |
| 398 | |
| 399 | static struct queue_sysfs_entry queue_logical_block_size_entry = { |
| 400 | .attr = {.name = "logical_block_size", .mode = S_IRUGO }, |
| 401 | .show = queue_logical_block_size_show, |
| 402 | }; |
| 403 | |
| 404 | static struct queue_sysfs_entry queue_physical_block_size_entry = { |
| 405 | .attr = {.name = "physical_block_size", .mode = S_IRUGO }, |
| 406 | .show = queue_physical_block_size_show, |
| 407 | }; |
| 408 | |
| 409 | static struct queue_sysfs_entry queue_io_min_entry = { |
| 410 | .attr = {.name = "minimum_io_size", .mode = S_IRUGO }, |
| 411 | .show = queue_io_min_show, |
| 412 | }; |
| 413 | |
| 414 | static struct queue_sysfs_entry queue_io_opt_entry = { |
| 415 | .attr = {.name = "optimal_io_size", .mode = S_IRUGO }, |
| 416 | .show = queue_io_opt_show, |
| 417 | }; |
| 418 | |
| 419 | static struct queue_sysfs_entry queue_discard_granularity_entry = { |
| 420 | .attr = {.name = "discard_granularity", .mode = S_IRUGO }, |
| 421 | .show = queue_discard_granularity_show, |
| 422 | }; |
| 423 | |
| 424 | static struct queue_sysfs_entry queue_discard_max_hw_entry = { |
| 425 | .attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO }, |
| 426 | .show = queue_discard_max_hw_show, |
| 427 | }; |
| 428 | |
| 429 | static struct queue_sysfs_entry queue_discard_max_entry = { |
| 430 | .attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR }, |
| 431 | .show = queue_discard_max_show, |
| 432 | .store = queue_discard_max_store, |
| 433 | }; |
| 434 | |
| 435 | static struct queue_sysfs_entry queue_discard_zeroes_data_entry = { |
| 436 | .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO }, |
| 437 | .show = queue_discard_zeroes_data_show, |
| 438 | }; |
| 439 | |
| 440 | static struct queue_sysfs_entry queue_write_same_max_entry = { |
| 441 | .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO }, |
| 442 | .show = queue_write_same_max_show, |
| 443 | }; |
| 444 | |
| 445 | static struct queue_sysfs_entry queue_nonrot_entry = { |
| 446 | .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR }, |
| 447 | .show = queue_show_nonrot, |
| 448 | .store = queue_store_nonrot, |
| 449 | }; |
| 450 | |
| 451 | static struct queue_sysfs_entry queue_nomerges_entry = { |
| 452 | .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR }, |
| 453 | .show = queue_nomerges_show, |
| 454 | .store = queue_nomerges_store, |
| 455 | }; |
| 456 | |
| 457 | static struct queue_sysfs_entry queue_rq_affinity_entry = { |
| 458 | .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR }, |
| 459 | .show = queue_rq_affinity_show, |
| 460 | .store = queue_rq_affinity_store, |
| 461 | }; |
| 462 | |
| 463 | static struct queue_sysfs_entry queue_iostats_entry = { |
| 464 | .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR }, |
| 465 | .show = queue_show_iostats, |
| 466 | .store = queue_store_iostats, |
| 467 | }; |
| 468 | |
| 469 | static struct queue_sysfs_entry queue_random_entry = { |
| 470 | .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR }, |
| 471 | .show = queue_show_random, |
| 472 | .store = queue_store_random, |
| 473 | }; |
| 474 | |
| 475 | static struct queue_sysfs_entry queue_poll_entry = { |
| 476 | .attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR }, |
| 477 | .show = queue_poll_show, |
| 478 | .store = queue_poll_store, |
| 479 | }; |
| 480 | |
| 481 | static struct attribute *default_attrs[] = { |
| 482 | &queue_requests_entry.attr, |
| 483 | &queue_ra_entry.attr, |
| 484 | &queue_max_hw_sectors_entry.attr, |
| 485 | &queue_max_sectors_entry.attr, |
| 486 | &queue_max_segments_entry.attr, |
| 487 | &queue_max_integrity_segments_entry.attr, |
| 488 | &queue_max_segment_size_entry.attr, |
| 489 | &queue_iosched_entry.attr, |
| 490 | &queue_hw_sector_size_entry.attr, |
| 491 | &queue_logical_block_size_entry.attr, |
| 492 | &queue_physical_block_size_entry.attr, |
| 493 | &queue_io_min_entry.attr, |
| 494 | &queue_io_opt_entry.attr, |
| 495 | &queue_discard_granularity_entry.attr, |
| 496 | &queue_discard_max_entry.attr, |
| 497 | &queue_discard_max_hw_entry.attr, |
| 498 | &queue_discard_zeroes_data_entry.attr, |
| 499 | &queue_write_same_max_entry.attr, |
| 500 | &queue_nonrot_entry.attr, |
| 501 | &queue_nomerges_entry.attr, |
| 502 | &queue_rq_affinity_entry.attr, |
| 503 | &queue_iostats_entry.attr, |
| 504 | &queue_random_entry.attr, |
| 505 | &queue_poll_entry.attr, |
| 506 | NULL, |
| 507 | }; |
| 508 | |
| 509 | #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) |
| 510 | |
| 511 | static ssize_t |
| 512 | queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) |
| 513 | { |
| 514 | struct queue_sysfs_entry *entry = to_queue(attr); |
| 515 | struct request_queue *q = |
| 516 | container_of(kobj, struct request_queue, kobj); |
| 517 | ssize_t res; |
| 518 | |
| 519 | if (!entry->show) |
| 520 | return -EIO; |
| 521 | mutex_lock(&q->sysfs_lock); |
| 522 | if (blk_queue_dying(q)) { |
| 523 | mutex_unlock(&q->sysfs_lock); |
| 524 | return -ENOENT; |
| 525 | } |
| 526 | res = entry->show(q, page); |
| 527 | mutex_unlock(&q->sysfs_lock); |
| 528 | return res; |
| 529 | } |
| 530 | |
| 531 | static ssize_t |
| 532 | queue_attr_store(struct kobject *kobj, struct attribute *attr, |
| 533 | const char *page, size_t length) |
| 534 | { |
| 535 | struct queue_sysfs_entry *entry = to_queue(attr); |
| 536 | struct request_queue *q; |
| 537 | ssize_t res; |
| 538 | |
| 539 | if (!entry->store) |
| 540 | return -EIO; |
| 541 | |
| 542 | q = container_of(kobj, struct request_queue, kobj); |
| 543 | mutex_lock(&q->sysfs_lock); |
| 544 | if (blk_queue_dying(q)) { |
| 545 | mutex_unlock(&q->sysfs_lock); |
| 546 | return -ENOENT; |
| 547 | } |
| 548 | res = entry->store(q, page, length); |
| 549 | mutex_unlock(&q->sysfs_lock); |
| 550 | return res; |
| 551 | } |
| 552 | |
| 553 | static void blk_free_queue_rcu(struct rcu_head *rcu_head) |
| 554 | { |
| 555 | struct request_queue *q = container_of(rcu_head, struct request_queue, |
| 556 | rcu_head); |
| 557 | kmem_cache_free(blk_requestq_cachep, q); |
| 558 | } |
| 559 | |
| 560 | /** |
| 561 | * blk_release_queue: - release a &struct request_queue when it is no longer needed |
| 562 | * @kobj: the kobj belonging to the request queue to be released |
| 563 | * |
| 564 | * Description: |
| 565 | * blk_release_queue is the pair to blk_init_queue() or |
| 566 | * blk_queue_make_request(). It should be called when a request queue is |
| 567 | * being released; typically when a block device is being de-registered. |
| 568 | * Currently, its primary task it to free all the &struct request |
| 569 | * structures that were allocated to the queue and the queue itself. |
| 570 | * |
| 571 | * Note: |
| 572 | * The low level driver must have finished any outstanding requests first |
| 573 | * via blk_cleanup_queue(). |
| 574 | **/ |
| 575 | static void blk_release_queue(struct kobject *kobj) |
| 576 | { |
| 577 | struct request_queue *q = |
| 578 | container_of(kobj, struct request_queue, kobj); |
| 579 | |
| 580 | bdi_exit(&q->backing_dev_info); |
| 581 | blkcg_exit_queue(q); |
| 582 | |
| 583 | if (q->elevator) { |
| 584 | spin_lock_irq(q->queue_lock); |
| 585 | ioc_clear_queue(q); |
| 586 | spin_unlock_irq(q->queue_lock); |
| 587 | elevator_exit(q->elevator); |
| 588 | } |
| 589 | |
| 590 | blk_exit_rl(&q->root_rl); |
| 591 | |
| 592 | if (q->queue_tags) |
| 593 | __blk_queue_free_tags(q); |
| 594 | |
| 595 | if (!q->mq_ops) |
| 596 | blk_free_flush_queue(q->fq); |
| 597 | else |
| 598 | blk_mq_release(q); |
| 599 | |
| 600 | blk_trace_shutdown(q); |
| 601 | |
| 602 | if (q->bio_split) |
| 603 | bioset_free(q->bio_split); |
| 604 | |
| 605 | ida_simple_remove(&blk_queue_ida, q->id); |
| 606 | call_rcu(&q->rcu_head, blk_free_queue_rcu); |
| 607 | } |
| 608 | |
| 609 | static const struct sysfs_ops queue_sysfs_ops = { |
| 610 | .show = queue_attr_show, |
| 611 | .store = queue_attr_store, |
| 612 | }; |
| 613 | |
| 614 | struct kobj_type blk_queue_ktype = { |
| 615 | .sysfs_ops = &queue_sysfs_ops, |
| 616 | .default_attrs = default_attrs, |
| 617 | .release = blk_release_queue, |
| 618 | }; |
| 619 | |
| 620 | int blk_register_queue(struct gendisk *disk) |
| 621 | { |
| 622 | int ret; |
| 623 | struct device *dev = disk_to_dev(disk); |
| 624 | struct request_queue *q = disk->queue; |
| 625 | |
| 626 | if (WARN_ON(!q)) |
| 627 | return -ENXIO; |
| 628 | |
| 629 | /* |
| 630 | * SCSI probing may synchronously create and destroy a lot of |
| 631 | * request_queues for non-existent devices. Shutting down a fully |
| 632 | * functional queue takes measureable wallclock time as RCU grace |
| 633 | * periods are involved. To avoid excessive latency in these |
| 634 | * cases, a request_queue starts out in a degraded mode which is |
| 635 | * faster to shut down and is made fully functional here as |
| 636 | * request_queues for non-existent devices never get registered. |
| 637 | */ |
| 638 | if (!blk_queue_init_done(q)) { |
| 639 | queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q); |
| 640 | percpu_ref_switch_to_percpu(&q->q_usage_counter); |
| 641 | blk_queue_bypass_end(q); |
| 642 | } |
| 643 | |
| 644 | ret = blk_trace_init_sysfs(dev); |
| 645 | if (ret) |
| 646 | return ret; |
| 647 | |
| 648 | ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); |
| 649 | if (ret < 0) { |
| 650 | blk_trace_remove_sysfs(dev); |
| 651 | return ret; |
| 652 | } |
| 653 | |
| 654 | kobject_uevent(&q->kobj, KOBJ_ADD); |
| 655 | |
| 656 | if (q->mq_ops) |
| 657 | blk_mq_register_disk(disk); |
| 658 | |
| 659 | if (!q->request_fn) |
| 660 | return 0; |
| 661 | |
| 662 | ret = elv_register_queue(q); |
| 663 | if (ret) { |
| 664 | kobject_uevent(&q->kobj, KOBJ_REMOVE); |
| 665 | kobject_del(&q->kobj); |
| 666 | blk_trace_remove_sysfs(dev); |
| 667 | kobject_put(&dev->kobj); |
| 668 | return ret; |
| 669 | } |
| 670 | |
| 671 | return 0; |
| 672 | } |
| 673 | |
| 674 | void blk_unregister_queue(struct gendisk *disk) |
| 675 | { |
| 676 | struct request_queue *q = disk->queue; |
| 677 | |
| 678 | if (WARN_ON(!q)) |
| 679 | return; |
| 680 | |
| 681 | if (q->mq_ops) |
| 682 | blk_mq_unregister_disk(disk); |
| 683 | |
| 684 | if (q->request_fn) |
| 685 | elv_unregister_queue(q); |
| 686 | |
| 687 | kobject_uevent(&q->kobj, KOBJ_REMOVE); |
| 688 | kobject_del(&q->kobj); |
| 689 | blk_trace_remove_sysfs(disk_to_dev(disk)); |
| 690 | kobject_put(&disk_to_dev(disk)->kobj); |
| 691 | } |