1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Add configfs and memory store: Kyungchan Koh <kkc6196@fb.com> and 4 * Shaohua Li <shli@fb.com> 5 */ 6 #include <linux/module.h> 7 8 #include <linux/moduleparam.h> 9 #include <linux/sched.h> 10 #include <linux/fs.h> 11 #include <linux/init.h> 12 #include "null_blk.h" 13 14 #define FREE_BATCH 16 15 16 #define TICKS_PER_SEC 50ULL 17 #define TIMER_INTERVAL (NSEC_PER_SEC / TICKS_PER_SEC) 18 19 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 20 static DECLARE_FAULT_ATTR(null_timeout_attr); 21 static DECLARE_FAULT_ATTR(null_requeue_attr); 22 static DECLARE_FAULT_ATTR(null_init_hctx_attr); 23 #endif 24 25 static inline u64 mb_per_tick(int mbps) 26 { 27 return (1 << 20) / TICKS_PER_SEC * ((u64) mbps); 28 } 29 30 /* 31 * Status flags for nullb_device. 32 * 33 * CONFIGURED: Device has been configured and turned on. Cannot reconfigure. 34 * UP: Device is currently on and visible in userspace. 35 * THROTTLED: Device is being throttled. 36 * CACHE: Device is using a write-back cache. 37 */ 38 enum nullb_device_flags { 39 NULLB_DEV_FL_CONFIGURED = 0, 40 NULLB_DEV_FL_UP = 1, 41 NULLB_DEV_FL_THROTTLED = 2, 42 NULLB_DEV_FL_CACHE = 3, 43 }; 44 45 #define MAP_SZ ((PAGE_SIZE >> SECTOR_SHIFT) + 2) 46 /* 47 * nullb_page is a page in memory for nullb devices. 48 * 49 * @page: The page holding the data. 50 * @bitmap: The bitmap represents which sector in the page has data. 51 * Each bit represents one block size. For example, sector 8 52 * will use the 7th bit 53 * The highest 2 bits of bitmap are for special purpose. LOCK means the cache 54 * page is being flushing to storage. FREE means the cache page is freed and 55 * should be skipped from flushing to storage. Please see 56 * null_make_cache_space 57 */ 58 struct nullb_page { 59 struct page *page; 60 DECLARE_BITMAP(bitmap, MAP_SZ); 61 }; 62 #define NULLB_PAGE_LOCK (MAP_SZ - 1) 63 #define NULLB_PAGE_FREE (MAP_SZ - 2) 64 65 static LIST_HEAD(nullb_list); 66 static struct mutex lock; 67 static int null_major; 68 static DEFINE_IDA(nullb_indexes); 69 static struct blk_mq_tag_set tag_set; 70 71 enum { 72 NULL_IRQ_NONE = 0, 73 NULL_IRQ_SOFTIRQ = 1, 74 NULL_IRQ_TIMER = 2, 75 }; 76 77 enum { 78 NULL_Q_BIO = 0, 79 NULL_Q_RQ = 1, 80 NULL_Q_MQ = 2, 81 }; 82 83 static bool g_virt_boundary = false; 84 module_param_named(virt_boundary, g_virt_boundary, bool, 0444); 85 MODULE_PARM_DESC(virt_boundary, "Require a virtual boundary for the device. Default: False"); 86 87 static int g_no_sched; 88 module_param_named(no_sched, g_no_sched, int, 0444); 89 MODULE_PARM_DESC(no_sched, "No io scheduler"); 90 91 static int g_submit_queues = 1; 92 module_param_named(submit_queues, g_submit_queues, int, 0444); 93 MODULE_PARM_DESC(submit_queues, "Number of submission queues"); 94 95 static int g_poll_queues = 1; 96 module_param_named(poll_queues, g_poll_queues, int, 0444); 97 MODULE_PARM_DESC(poll_queues, "Number of IOPOLL submission queues"); 98 99 static int g_home_node = NUMA_NO_NODE; 100 module_param_named(home_node, g_home_node, int, 0444); 101 MODULE_PARM_DESC(home_node, "Home node for the device"); 102 103 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 104 /* 105 * For more details about fault injection, please refer to 106 * Documentation/fault-injection/fault-injection.rst. 107 */ 108 static char g_timeout_str[80]; 109 module_param_string(timeout, g_timeout_str, sizeof(g_timeout_str), 0444); 110 MODULE_PARM_DESC(timeout, "Fault injection. timeout=<interval>,<probability>,<space>,<times>"); 111 112 static char g_requeue_str[80]; 113 module_param_string(requeue, g_requeue_str, sizeof(g_requeue_str), 0444); 114 MODULE_PARM_DESC(requeue, "Fault injection. requeue=<interval>,<probability>,<space>,<times>"); 115 116 static char g_init_hctx_str[80]; 117 module_param_string(init_hctx, g_init_hctx_str, sizeof(g_init_hctx_str), 0444); 118 MODULE_PARM_DESC(init_hctx, "Fault injection to fail hctx init. init_hctx=<interval>,<probability>,<space>,<times>"); 119 #endif 120 121 static int g_queue_mode = NULL_Q_MQ; 122 123 static int null_param_store_val(const char *str, int *val, int min, int max) 124 { 125 int ret, new_val; 126 127 ret = kstrtoint(str, 10, &new_val); 128 if (ret) 129 return -EINVAL; 130 131 if (new_val < min || new_val > max) 132 return -EINVAL; 133 134 *val = new_val; 135 return 0; 136 } 137 138 static int null_set_queue_mode(const char *str, const struct kernel_param *kp) 139 { 140 return null_param_store_val(str, &g_queue_mode, NULL_Q_BIO, NULL_Q_MQ); 141 } 142 143 static const struct kernel_param_ops null_queue_mode_param_ops = { 144 .set = null_set_queue_mode, 145 .get = param_get_int, 146 }; 147 148 device_param_cb(queue_mode, &null_queue_mode_param_ops, &g_queue_mode, 0444); 149 MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)"); 150 151 static int g_gb = 250; 152 module_param_named(gb, g_gb, int, 0444); 153 MODULE_PARM_DESC(gb, "Size in GB"); 154 155 static int g_bs = 512; 156 module_param_named(bs, g_bs, int, 0444); 157 MODULE_PARM_DESC(bs, "Block size (in bytes)"); 158 159 static int g_max_sectors; 160 module_param_named(max_sectors, g_max_sectors, int, 0444); 161 MODULE_PARM_DESC(max_sectors, "Maximum size of a command (in 512B sectors)"); 162 163 static unsigned int nr_devices = 1; 164 module_param(nr_devices, uint, 0444); 165 MODULE_PARM_DESC(nr_devices, "Number of devices to register"); 166 167 static bool g_blocking; 168 module_param_named(blocking, g_blocking, bool, 0444); 169 MODULE_PARM_DESC(blocking, "Register as a blocking blk-mq driver device"); 170 171 static bool shared_tags; 172 module_param(shared_tags, bool, 0444); 173 MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq"); 174 175 static bool g_shared_tag_bitmap; 176 module_param_named(shared_tag_bitmap, g_shared_tag_bitmap, bool, 0444); 177 MODULE_PARM_DESC(shared_tag_bitmap, "Use shared tag bitmap for all submission queues for blk-mq"); 178 179 static int g_irqmode = NULL_IRQ_SOFTIRQ; 180 181 static int null_set_irqmode(const char *str, const struct kernel_param *kp) 182 { 183 return null_param_store_val(str, &g_irqmode, NULL_IRQ_NONE, 184 NULL_IRQ_TIMER); 185 } 186 187 static const struct kernel_param_ops null_irqmode_param_ops = { 188 .set = null_set_irqmode, 189 .get = param_get_int, 190 }; 191 192 device_param_cb(irqmode, &null_irqmode_param_ops, &g_irqmode, 0444); 193 MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer"); 194 195 static unsigned long g_completion_nsec = 10000; 196 module_param_named(completion_nsec, g_completion_nsec, ulong, 0444); 197 MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns"); 198 199 static int g_hw_queue_depth = 64; 200 module_param_named(hw_queue_depth, g_hw_queue_depth, int, 0444); 201 MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64"); 202 203 static bool g_use_per_node_hctx; 204 module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444); 205 MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); 206 207 static bool g_zoned; 208 module_param_named(zoned, g_zoned, bool, S_IRUGO); 209 MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false"); 210 211 static unsigned long g_zone_size = 256; 212 module_param_named(zone_size, g_zone_size, ulong, S_IRUGO); 213 MODULE_PARM_DESC(zone_size, "Zone size in MB when block device is zoned. Must be power-of-two: Default: 256"); 214 215 static unsigned long g_zone_capacity; 216 module_param_named(zone_capacity, g_zone_capacity, ulong, 0444); 217 MODULE_PARM_DESC(zone_capacity, "Zone capacity in MB when block device is zoned. Can be less than or equal to zone size. Default: Zone size"); 218 219 static unsigned int g_zone_nr_conv; 220 module_param_named(zone_nr_conv, g_zone_nr_conv, uint, 0444); 221 MODULE_PARM_DESC(zone_nr_conv, "Number of conventional zones when block device is zoned. Default: 0"); 222 223 static unsigned int g_zone_max_open; 224 module_param_named(zone_max_open, g_zone_max_open, uint, 0444); 225 MODULE_PARM_DESC(zone_max_open, "Maximum number of open zones when block device is zoned. Default: 0 (no limit)"); 226 227 static unsigned int g_zone_max_active; 228 module_param_named(zone_max_active, g_zone_max_active, uint, 0444); 229 MODULE_PARM_DESC(zone_max_active, "Maximum number of active zones when block device is zoned. Default: 0 (no limit)"); 230 231 static struct nullb_device *null_alloc_dev(void); 232 static void null_free_dev(struct nullb_device *dev); 233 static void null_del_dev(struct nullb *nullb); 234 static int null_add_dev(struct nullb_device *dev); 235 static void null_free_device_storage(struct nullb_device *dev, bool is_cache); 236 237 static inline struct nullb_device *to_nullb_device(struct config_item *item) 238 { 239 return item ? container_of(item, struct nullb_device, item) : NULL; 240 } 241 242 static inline ssize_t nullb_device_uint_attr_show(unsigned int val, char *page) 243 { 244 return snprintf(page, PAGE_SIZE, "%u\n", val); 245 } 246 247 static inline ssize_t nullb_device_ulong_attr_show(unsigned long val, 248 char *page) 249 { 250 return snprintf(page, PAGE_SIZE, "%lu\n", val); 251 } 252 253 static inline ssize_t nullb_device_bool_attr_show(bool val, char *page) 254 { 255 return snprintf(page, PAGE_SIZE, "%u\n", val); 256 } 257 258 static ssize_t nullb_device_uint_attr_store(unsigned int *val, 259 const char *page, size_t count) 260 { 261 unsigned int tmp; 262 int result; 263 264 result = kstrtouint(page, 0, &tmp); 265 if (result < 0) 266 return result; 267 268 *val = tmp; 269 return count; 270 } 271 272 static ssize_t nullb_device_ulong_attr_store(unsigned long *val, 273 const char *page, size_t count) 274 { 275 int result; 276 unsigned long tmp; 277 278 result = kstrtoul(page, 0, &tmp); 279 if (result < 0) 280 return result; 281 282 *val = tmp; 283 return count; 284 } 285 286 static ssize_t nullb_device_bool_attr_store(bool *val, const char *page, 287 size_t count) 288 { 289 bool tmp; 290 int result; 291 292 result = kstrtobool(page, &tmp); 293 if (result < 0) 294 return result; 295 296 *val = tmp; 297 return count; 298 } 299 300 /* The following macro should only be used with TYPE = {uint, ulong, bool}. */ 301 #define NULLB_DEVICE_ATTR(NAME, TYPE, APPLY) \ 302 static ssize_t \ 303 nullb_device_##NAME##_show(struct config_item *item, char *page) \ 304 { \ 305 return nullb_device_##TYPE##_attr_show( \ 306 to_nullb_device(item)->NAME, page); \ 307 } \ 308 static ssize_t \ 309 nullb_device_##NAME##_store(struct config_item *item, const char *page, \ 310 size_t count) \ 311 { \ 312 int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;\ 313 struct nullb_device *dev = to_nullb_device(item); \ 314 TYPE new_value = 0; \ 315 int ret; \ 316 \ 317 ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);\ 318 if (ret < 0) \ 319 return ret; \ 320 if (apply_fn) \ 321 ret = apply_fn(dev, new_value); \ 322 else if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) \ 323 ret = -EBUSY; \ 324 if (ret < 0) \ 325 return ret; \ 326 dev->NAME = new_value; \ 327 return count; \ 328 } \ 329 CONFIGFS_ATTR(nullb_device_, NAME); 330 331 static int nullb_update_nr_hw_queues(struct nullb_device *dev, 332 unsigned int submit_queues, 333 unsigned int poll_queues) 334 335 { 336 struct blk_mq_tag_set *set; 337 int ret, nr_hw_queues; 338 339 if (!dev->nullb) 340 return 0; 341 342 /* 343 * Make sure at least one submit queue exists. 344 */ 345 if (!submit_queues) 346 return -EINVAL; 347 348 /* 349 * Make sure that null_init_hctx() does not access nullb->queues[] past 350 * the end of that array. 351 */ 352 if (submit_queues > nr_cpu_ids || poll_queues > g_poll_queues) 353 return -EINVAL; 354 355 /* 356 * Keep previous and new queue numbers in nullb_device for reference in 357 * the call back function null_map_queues(). 358 */ 359 dev->prev_submit_queues = dev->submit_queues; 360 dev->prev_poll_queues = dev->poll_queues; 361 dev->submit_queues = submit_queues; 362 dev->poll_queues = poll_queues; 363 364 set = dev->nullb->tag_set; 365 nr_hw_queues = submit_queues + poll_queues; 366 blk_mq_update_nr_hw_queues(set, nr_hw_queues); 367 ret = set->nr_hw_queues == nr_hw_queues ? 0 : -ENOMEM; 368 369 if (ret) { 370 /* on error, revert the queue numbers */ 371 dev->submit_queues = dev->prev_submit_queues; 372 dev->poll_queues = dev->prev_poll_queues; 373 } 374 375 return ret; 376 } 377 378 static int nullb_apply_submit_queues(struct nullb_device *dev, 379 unsigned int submit_queues) 380 { 381 return nullb_update_nr_hw_queues(dev, submit_queues, dev->poll_queues); 382 } 383 384 static int nullb_apply_poll_queues(struct nullb_device *dev, 385 unsigned int poll_queues) 386 { 387 return nullb_update_nr_hw_queues(dev, dev->submit_queues, poll_queues); 388 } 389 390 NULLB_DEVICE_ATTR(size, ulong, NULL); 391 NULLB_DEVICE_ATTR(completion_nsec, ulong, NULL); 392 NULLB_DEVICE_ATTR(submit_queues, uint, nullb_apply_submit_queues); 393 NULLB_DEVICE_ATTR(poll_queues, uint, nullb_apply_poll_queues); 394 NULLB_DEVICE_ATTR(home_node, uint, NULL); 395 NULLB_DEVICE_ATTR(queue_mode, uint, NULL); 396 NULLB_DEVICE_ATTR(blocksize, uint, NULL); 397 NULLB_DEVICE_ATTR(max_sectors, uint, NULL); 398 NULLB_DEVICE_ATTR(irqmode, uint, NULL); 399 NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL); 400 NULLB_DEVICE_ATTR(index, uint, NULL); 401 NULLB_DEVICE_ATTR(blocking, bool, NULL); 402 NULLB_DEVICE_ATTR(use_per_node_hctx, bool, NULL); 403 NULLB_DEVICE_ATTR(memory_backed, bool, NULL); 404 NULLB_DEVICE_ATTR(discard, bool, NULL); 405 NULLB_DEVICE_ATTR(mbps, uint, NULL); 406 NULLB_DEVICE_ATTR(cache_size, ulong, NULL); 407 NULLB_DEVICE_ATTR(zoned, bool, NULL); 408 NULLB_DEVICE_ATTR(zone_size, ulong, NULL); 409 NULLB_DEVICE_ATTR(zone_capacity, ulong, NULL); 410 NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL); 411 NULLB_DEVICE_ATTR(zone_max_open, uint, NULL); 412 NULLB_DEVICE_ATTR(zone_max_active, uint, NULL); 413 NULLB_DEVICE_ATTR(virt_boundary, bool, NULL); 414 415 static ssize_t nullb_device_power_show(struct config_item *item, char *page) 416 { 417 return nullb_device_bool_attr_show(to_nullb_device(item)->power, page); 418 } 419 420 static ssize_t nullb_device_power_store(struct config_item *item, 421 const char *page, size_t count) 422 { 423 struct nullb_device *dev = to_nullb_device(item); 424 bool newp = false; 425 ssize_t ret; 426 427 ret = nullb_device_bool_attr_store(&newp, page, count); 428 if (ret < 0) 429 return ret; 430 431 if (!dev->power && newp) { 432 if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags)) 433 return count; 434 ret = null_add_dev(dev); 435 if (ret) { 436 clear_bit(NULLB_DEV_FL_UP, &dev->flags); 437 return ret; 438 } 439 440 set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); 441 dev->power = newp; 442 } else if (dev->power && !newp) { 443 if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) { 444 mutex_lock(&lock); 445 dev->power = newp; 446 null_del_dev(dev->nullb); 447 mutex_unlock(&lock); 448 } 449 clear_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags); 450 } 451 452 return count; 453 } 454 455 CONFIGFS_ATTR(nullb_device_, power); 456 457 static ssize_t nullb_device_badblocks_show(struct config_item *item, char *page) 458 { 459 struct nullb_device *t_dev = to_nullb_device(item); 460 461 return badblocks_show(&t_dev->badblocks, page, 0); 462 } 463 464 static ssize_t nullb_device_badblocks_store(struct config_item *item, 465 const char *page, size_t count) 466 { 467 struct nullb_device *t_dev = to_nullb_device(item); 468 char *orig, *buf, *tmp; 469 u64 start, end; 470 int ret; 471 472 orig = kstrndup(page, count, GFP_KERNEL); 473 if (!orig) 474 return -ENOMEM; 475 476 buf = strstrip(orig); 477 478 ret = -EINVAL; 479 if (buf[0] != '+' && buf[0] != '-') 480 goto out; 481 tmp = strchr(&buf[1], '-'); 482 if (!tmp) 483 goto out; 484 *tmp = '\0'; 485 ret = kstrtoull(buf + 1, 0, &start); 486 if (ret) 487 goto out; 488 ret = kstrtoull(tmp + 1, 0, &end); 489 if (ret) 490 goto out; 491 ret = -EINVAL; 492 if (start > end) 493 goto out; 494 /* enable badblocks */ 495 cmpxchg(&t_dev->badblocks.shift, -1, 0); 496 if (buf[0] == '+') 497 ret = badblocks_set(&t_dev->badblocks, start, 498 end - start + 1, 1); 499 else 500 ret = badblocks_clear(&t_dev->badblocks, start, 501 end - start + 1); 502 if (ret == 0) 503 ret = count; 504 out: 505 kfree(orig); 506 return ret; 507 } 508 CONFIGFS_ATTR(nullb_device_, badblocks); 509 510 static struct configfs_attribute *nullb_device_attrs[] = { 511 &nullb_device_attr_size, 512 &nullb_device_attr_completion_nsec, 513 &nullb_device_attr_submit_queues, 514 &nullb_device_attr_poll_queues, 515 &nullb_device_attr_home_node, 516 &nullb_device_attr_queue_mode, 517 &nullb_device_attr_blocksize, 518 &nullb_device_attr_max_sectors, 519 &nullb_device_attr_irqmode, 520 &nullb_device_attr_hw_queue_depth, 521 &nullb_device_attr_index, 522 &nullb_device_attr_blocking, 523 &nullb_device_attr_use_per_node_hctx, 524 &nullb_device_attr_power, 525 &nullb_device_attr_memory_backed, 526 &nullb_device_attr_discard, 527 &nullb_device_attr_mbps, 528 &nullb_device_attr_cache_size, 529 &nullb_device_attr_badblocks, 530 &nullb_device_attr_zoned, 531 &nullb_device_attr_zone_size, 532 &nullb_device_attr_zone_capacity, 533 &nullb_device_attr_zone_nr_conv, 534 &nullb_device_attr_zone_max_open, 535 &nullb_device_attr_zone_max_active, 536 &nullb_device_attr_virt_boundary, 537 NULL, 538 }; 539 540 static void nullb_device_release(struct config_item *item) 541 { 542 struct nullb_device *dev = to_nullb_device(item); 543 544 null_free_device_storage(dev, false); 545 null_free_dev(dev); 546 } 547 548 static struct configfs_item_operations nullb_device_ops = { 549 .release = nullb_device_release, 550 }; 551 552 static const struct config_item_type nullb_device_type = { 553 .ct_item_ops = &nullb_device_ops, 554 .ct_attrs = nullb_device_attrs, 555 .ct_owner = THIS_MODULE, 556 }; 557 558 static struct 559 config_item *nullb_group_make_item(struct config_group *group, const char *name) 560 { 561 struct nullb_device *dev; 562 563 dev = null_alloc_dev(); 564 if (!dev) 565 return ERR_PTR(-ENOMEM); 566 567 config_item_init_type_name(&dev->item, name, &nullb_device_type); 568 569 return &dev->item; 570 } 571 572 static void 573 nullb_group_drop_item(struct config_group *group, struct config_item *item) 574 { 575 struct nullb_device *dev = to_nullb_device(item); 576 577 if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) { 578 mutex_lock(&lock); 579 dev->power = false; 580 null_del_dev(dev->nullb); 581 mutex_unlock(&lock); 582 } 583 584 config_item_put(item); 585 } 586 587 static ssize_t memb_group_features_show(struct config_item *item, char *page) 588 { 589 return snprintf(page, PAGE_SIZE, 590 "memory_backed,discard,bandwidth,cache,badblocks,zoned,zone_size,zone_capacity,zone_nr_conv,zone_max_open,zone_max_active,blocksize,max_sectors,virt_boundary\n"); 591 } 592 593 CONFIGFS_ATTR_RO(memb_group_, features); 594 595 static struct configfs_attribute *nullb_group_attrs[] = { 596 &memb_group_attr_features, 597 NULL, 598 }; 599 600 static struct configfs_group_operations nullb_group_ops = { 601 .make_item = nullb_group_make_item, 602 .drop_item = nullb_group_drop_item, 603 }; 604 605 static const struct config_item_type nullb_group_type = { 606 .ct_group_ops = &nullb_group_ops, 607 .ct_attrs = nullb_group_attrs, 608 .ct_owner = THIS_MODULE, 609 }; 610 611 static struct configfs_subsystem nullb_subsys = { 612 .su_group = { 613 .cg_item = { 614 .ci_namebuf = "nullb", 615 .ci_type = &nullb_group_type, 616 }, 617 }, 618 }; 619 620 static inline int null_cache_active(struct nullb *nullb) 621 { 622 return test_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); 623 } 624 625 static struct nullb_device *null_alloc_dev(void) 626 { 627 struct nullb_device *dev; 628 629 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 630 if (!dev) 631 return NULL; 632 INIT_RADIX_TREE(&dev->data, GFP_ATOMIC); 633 INIT_RADIX_TREE(&dev->cache, GFP_ATOMIC); 634 if (badblocks_init(&dev->badblocks, 0)) { 635 kfree(dev); 636 return NULL; 637 } 638 639 dev->size = g_gb * 1024; 640 dev->completion_nsec = g_completion_nsec; 641 dev->submit_queues = g_submit_queues; 642 dev->prev_submit_queues = g_submit_queues; 643 dev->poll_queues = g_poll_queues; 644 dev->prev_poll_queues = g_poll_queues; 645 dev->home_node = g_home_node; 646 dev->queue_mode = g_queue_mode; 647 dev->blocksize = g_bs; 648 dev->max_sectors = g_max_sectors; 649 dev->irqmode = g_irqmode; 650 dev->hw_queue_depth = g_hw_queue_depth; 651 dev->blocking = g_blocking; 652 dev->use_per_node_hctx = g_use_per_node_hctx; 653 dev->zoned = g_zoned; 654 dev->zone_size = g_zone_size; 655 dev->zone_capacity = g_zone_capacity; 656 dev->zone_nr_conv = g_zone_nr_conv; 657 dev->zone_max_open = g_zone_max_open; 658 dev->zone_max_active = g_zone_max_active; 659 dev->virt_boundary = g_virt_boundary; 660 return dev; 661 } 662 663 static void null_free_dev(struct nullb_device *dev) 664 { 665 if (!dev) 666 return; 667 668 null_free_zoned_dev(dev); 669 badblocks_exit(&dev->badblocks); 670 kfree(dev); 671 } 672 673 static void put_tag(struct nullb_queue *nq, unsigned int tag) 674 { 675 clear_bit_unlock(tag, nq->tag_map); 676 677 if (waitqueue_active(&nq->wait)) 678 wake_up(&nq->wait); 679 } 680 681 static unsigned int get_tag(struct nullb_queue *nq) 682 { 683 unsigned int tag; 684 685 do { 686 tag = find_first_zero_bit(nq->tag_map, nq->queue_depth); 687 if (tag >= nq->queue_depth) 688 return -1U; 689 } while (test_and_set_bit_lock(tag, nq->tag_map)); 690 691 return tag; 692 } 693 694 static void free_cmd(struct nullb_cmd *cmd) 695 { 696 put_tag(cmd->nq, cmd->tag); 697 } 698 699 static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer); 700 701 static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq) 702 { 703 struct nullb_cmd *cmd; 704 unsigned int tag; 705 706 tag = get_tag(nq); 707 if (tag != -1U) { 708 cmd = &nq->cmds[tag]; 709 cmd->tag = tag; 710 cmd->error = BLK_STS_OK; 711 cmd->nq = nq; 712 if (nq->dev->irqmode == NULL_IRQ_TIMER) { 713 hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, 714 HRTIMER_MODE_REL); 715 cmd->timer.function = null_cmd_timer_expired; 716 } 717 return cmd; 718 } 719 720 return NULL; 721 } 722 723 static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, struct bio *bio) 724 { 725 struct nullb_cmd *cmd; 726 DEFINE_WAIT(wait); 727 728 do { 729 /* 730 * This avoids multiple return statements, multiple calls to 731 * __alloc_cmd() and a fast path call to prepare_to_wait(). 732 */ 733 cmd = __alloc_cmd(nq); 734 if (cmd) { 735 cmd->bio = bio; 736 return cmd; 737 } 738 prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE); 739 io_schedule(); 740 finish_wait(&nq->wait, &wait); 741 } while (1); 742 } 743 744 static void end_cmd(struct nullb_cmd *cmd) 745 { 746 int queue_mode = cmd->nq->dev->queue_mode; 747 748 switch (queue_mode) { 749 case NULL_Q_MQ: 750 blk_mq_end_request(cmd->rq, cmd->error); 751 return; 752 case NULL_Q_BIO: 753 cmd->bio->bi_status = cmd->error; 754 bio_endio(cmd->bio); 755 break; 756 } 757 758 free_cmd(cmd); 759 } 760 761 static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) 762 { 763 end_cmd(container_of(timer, struct nullb_cmd, timer)); 764 765 return HRTIMER_NORESTART; 766 } 767 768 static void null_cmd_end_timer(struct nullb_cmd *cmd) 769 { 770 ktime_t kt = cmd->nq->dev->completion_nsec; 771 772 hrtimer_start(&cmd->timer, kt, HRTIMER_MODE_REL); 773 } 774 775 static void null_complete_rq(struct request *rq) 776 { 777 end_cmd(blk_mq_rq_to_pdu(rq)); 778 } 779 780 static struct nullb_page *null_alloc_page(void) 781 { 782 struct nullb_page *t_page; 783 784 t_page = kmalloc(sizeof(struct nullb_page), GFP_NOIO); 785 if (!t_page) 786 return NULL; 787 788 t_page->page = alloc_pages(GFP_NOIO, 0); 789 if (!t_page->page) { 790 kfree(t_page); 791 return NULL; 792 } 793 794 memset(t_page->bitmap, 0, sizeof(t_page->bitmap)); 795 return t_page; 796 } 797 798 static void null_free_page(struct nullb_page *t_page) 799 { 800 __set_bit(NULLB_PAGE_FREE, t_page->bitmap); 801 if (test_bit(NULLB_PAGE_LOCK, t_page->bitmap)) 802 return; 803 __free_page(t_page->page); 804 kfree(t_page); 805 } 806 807 static bool null_page_empty(struct nullb_page *page) 808 { 809 int size = MAP_SZ - 2; 810 811 return find_first_bit(page->bitmap, size) == size; 812 } 813 814 static void null_free_sector(struct nullb *nullb, sector_t sector, 815 bool is_cache) 816 { 817 unsigned int sector_bit; 818 u64 idx; 819 struct nullb_page *t_page, *ret; 820 struct radix_tree_root *root; 821 822 root = is_cache ? &nullb->dev->cache : &nullb->dev->data; 823 idx = sector >> PAGE_SECTORS_SHIFT; 824 sector_bit = (sector & SECTOR_MASK); 825 826 t_page = radix_tree_lookup(root, idx); 827 if (t_page) { 828 __clear_bit(sector_bit, t_page->bitmap); 829 830 if (null_page_empty(t_page)) { 831 ret = radix_tree_delete_item(root, idx, t_page); 832 WARN_ON(ret != t_page); 833 null_free_page(ret); 834 if (is_cache) 835 nullb->dev->curr_cache -= PAGE_SIZE; 836 } 837 } 838 } 839 840 static struct nullb_page *null_radix_tree_insert(struct nullb *nullb, u64 idx, 841 struct nullb_page *t_page, bool is_cache) 842 { 843 struct radix_tree_root *root; 844 845 root = is_cache ? &nullb->dev->cache : &nullb->dev->data; 846 847 if (radix_tree_insert(root, idx, t_page)) { 848 null_free_page(t_page); 849 t_page = radix_tree_lookup(root, idx); 850 WARN_ON(!t_page || t_page->page->index != idx); 851 } else if (is_cache) 852 nullb->dev->curr_cache += PAGE_SIZE; 853 854 return t_page; 855 } 856 857 static void null_free_device_storage(struct nullb_device *dev, bool is_cache) 858 { 859 unsigned long pos = 0; 860 int nr_pages; 861 struct nullb_page *ret, *t_pages[FREE_BATCH]; 862 struct radix_tree_root *root; 863 864 root = is_cache ? &dev->cache : &dev->data; 865 866 do { 867 int i; 868 869 nr_pages = radix_tree_gang_lookup(root, 870 (void **)t_pages, pos, FREE_BATCH); 871 872 for (i = 0; i < nr_pages; i++) { 873 pos = t_pages[i]->page->index; 874 ret = radix_tree_delete_item(root, pos, t_pages[i]); 875 WARN_ON(ret != t_pages[i]); 876 null_free_page(ret); 877 } 878 879 pos++; 880 } while (nr_pages == FREE_BATCH); 881 882 if (is_cache) 883 dev->curr_cache = 0; 884 } 885 886 static struct nullb_page *__null_lookup_page(struct nullb *nullb, 887 sector_t sector, bool for_write, bool is_cache) 888 { 889 unsigned int sector_bit; 890 u64 idx; 891 struct nullb_page *t_page; 892 struct radix_tree_root *root; 893 894 idx = sector >> PAGE_SECTORS_SHIFT; 895 sector_bit = (sector & SECTOR_MASK); 896 897 root = is_cache ? &nullb->dev->cache : &nullb->dev->data; 898 t_page = radix_tree_lookup(root, idx); 899 WARN_ON(t_page && t_page->page->index != idx); 900 901 if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap))) 902 return t_page; 903 904 return NULL; 905 } 906 907 static struct nullb_page *null_lookup_page(struct nullb *nullb, 908 sector_t sector, bool for_write, bool ignore_cache) 909 { 910 struct nullb_page *page = NULL; 911 912 if (!ignore_cache) 913 page = __null_lookup_page(nullb, sector, for_write, true); 914 if (page) 915 return page; 916 return __null_lookup_page(nullb, sector, for_write, false); 917 } 918 919 static struct nullb_page *null_insert_page(struct nullb *nullb, 920 sector_t sector, bool ignore_cache) 921 __releases(&nullb->lock) 922 __acquires(&nullb->lock) 923 { 924 u64 idx; 925 struct nullb_page *t_page; 926 927 t_page = null_lookup_page(nullb, sector, true, ignore_cache); 928 if (t_page) 929 return t_page; 930 931 spin_unlock_irq(&nullb->lock); 932 933 t_page = null_alloc_page(); 934 if (!t_page) 935 goto out_lock; 936 937 if (radix_tree_preload(GFP_NOIO)) 938 goto out_freepage; 939 940 spin_lock_irq(&nullb->lock); 941 idx = sector >> PAGE_SECTORS_SHIFT; 942 t_page->page->index = idx; 943 t_page = null_radix_tree_insert(nullb, idx, t_page, !ignore_cache); 944 radix_tree_preload_end(); 945 946 return t_page; 947 out_freepage: 948 null_free_page(t_page); 949 out_lock: 950 spin_lock_irq(&nullb->lock); 951 return null_lookup_page(nullb, sector, true, ignore_cache); 952 } 953 954 static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page) 955 { 956 int i; 957 unsigned int offset; 958 u64 idx; 959 struct nullb_page *t_page, *ret; 960 void *dst, *src; 961 962 idx = c_page->page->index; 963 964 t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true); 965 966 __clear_bit(NULLB_PAGE_LOCK, c_page->bitmap); 967 if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) { 968 null_free_page(c_page); 969 if (t_page && null_page_empty(t_page)) { 970 ret = radix_tree_delete_item(&nullb->dev->data, 971 idx, t_page); 972 null_free_page(t_page); 973 } 974 return 0; 975 } 976 977 if (!t_page) 978 return -ENOMEM; 979 980 src = kmap_atomic(c_page->page); 981 dst = kmap_atomic(t_page->page); 982 983 for (i = 0; i < PAGE_SECTORS; 984 i += (nullb->dev->blocksize >> SECTOR_SHIFT)) { 985 if (test_bit(i, c_page->bitmap)) { 986 offset = (i << SECTOR_SHIFT); 987 memcpy(dst + offset, src + offset, 988 nullb->dev->blocksize); 989 __set_bit(i, t_page->bitmap); 990 } 991 } 992 993 kunmap_atomic(dst); 994 kunmap_atomic(src); 995 996 ret = radix_tree_delete_item(&nullb->dev->cache, idx, c_page); 997 null_free_page(ret); 998 nullb->dev->curr_cache -= PAGE_SIZE; 999 1000 return 0; 1001 } 1002 1003 static int null_make_cache_space(struct nullb *nullb, unsigned long n) 1004 { 1005 int i, err, nr_pages; 1006 struct nullb_page *c_pages[FREE_BATCH]; 1007 unsigned long flushed = 0, one_round; 1008 1009 again: 1010 if ((nullb->dev->cache_size * 1024 * 1024) > 1011 nullb->dev->curr_cache + n || nullb->dev->curr_cache == 0) 1012 return 0; 1013 1014 nr_pages = radix_tree_gang_lookup(&nullb->dev->cache, 1015 (void **)c_pages, nullb->cache_flush_pos, FREE_BATCH); 1016 /* 1017 * nullb_flush_cache_page could unlock before using the c_pages. To 1018 * avoid race, we don't allow page free 1019 */ 1020 for (i = 0; i < nr_pages; i++) { 1021 nullb->cache_flush_pos = c_pages[i]->page->index; 1022 /* 1023 * We found the page which is being flushed to disk by other 1024 * threads 1025 */ 1026 if (test_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap)) 1027 c_pages[i] = NULL; 1028 else 1029 __set_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap); 1030 } 1031 1032 one_round = 0; 1033 for (i = 0; i < nr_pages; i++) { 1034 if (c_pages[i] == NULL) 1035 continue; 1036 err = null_flush_cache_page(nullb, c_pages[i]); 1037 if (err) 1038 return err; 1039 one_round++; 1040 } 1041 flushed += one_round << PAGE_SHIFT; 1042 1043 if (n > flushed) { 1044 if (nr_pages == 0) 1045 nullb->cache_flush_pos = 0; 1046 if (one_round == 0) { 1047 /* give other threads a chance */ 1048 spin_unlock_irq(&nullb->lock); 1049 spin_lock_irq(&nullb->lock); 1050 } 1051 goto again; 1052 } 1053 return 0; 1054 } 1055 1056 static int copy_to_nullb(struct nullb *nullb, struct page *source, 1057 unsigned int off, sector_t sector, size_t n, bool is_fua) 1058 { 1059 size_t temp, count = 0; 1060 unsigned int offset; 1061 struct nullb_page *t_page; 1062 void *dst, *src; 1063 1064 while (count < n) { 1065 temp = min_t(size_t, nullb->dev->blocksize, n - count); 1066 1067 if (null_cache_active(nullb) && !is_fua) 1068 null_make_cache_space(nullb, PAGE_SIZE); 1069 1070 offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; 1071 t_page = null_insert_page(nullb, sector, 1072 !null_cache_active(nullb) || is_fua); 1073 if (!t_page) 1074 return -ENOSPC; 1075 1076 src = kmap_atomic(source); 1077 dst = kmap_atomic(t_page->page); 1078 memcpy(dst + offset, src + off + count, temp); 1079 kunmap_atomic(dst); 1080 kunmap_atomic(src); 1081 1082 __set_bit(sector & SECTOR_MASK, t_page->bitmap); 1083 1084 if (is_fua) 1085 null_free_sector(nullb, sector, true); 1086 1087 count += temp; 1088 sector += temp >> SECTOR_SHIFT; 1089 } 1090 return 0; 1091 } 1092 1093 static int copy_from_nullb(struct nullb *nullb, struct page *dest, 1094 unsigned int off, sector_t sector, size_t n) 1095 { 1096 size_t temp, count = 0; 1097 unsigned int offset; 1098 struct nullb_page *t_page; 1099 void *dst, *src; 1100 1101 while (count < n) { 1102 temp = min_t(size_t, nullb->dev->blocksize, n - count); 1103 1104 offset = (sector & SECTOR_MASK) << SECTOR_SHIFT; 1105 t_page = null_lookup_page(nullb, sector, false, 1106 !null_cache_active(nullb)); 1107 1108 dst = kmap_atomic(dest); 1109 if (!t_page) { 1110 memset(dst + off + count, 0, temp); 1111 goto next; 1112 } 1113 src = kmap_atomic(t_page->page); 1114 memcpy(dst + off + count, src + offset, temp); 1115 kunmap_atomic(src); 1116 next: 1117 kunmap_atomic(dst); 1118 1119 count += temp; 1120 sector += temp >> SECTOR_SHIFT; 1121 } 1122 return 0; 1123 } 1124 1125 static void nullb_fill_pattern(struct nullb *nullb, struct page *page, 1126 unsigned int len, unsigned int off) 1127 { 1128 void *dst; 1129 1130 dst = kmap_atomic(page); 1131 memset(dst + off, 0xFF, len); 1132 kunmap_atomic(dst); 1133 } 1134 1135 blk_status_t null_handle_discard(struct nullb_device *dev, 1136 sector_t sector, sector_t nr_sectors) 1137 { 1138 struct nullb *nullb = dev->nullb; 1139 size_t n = nr_sectors << SECTOR_SHIFT; 1140 size_t temp; 1141 1142 spin_lock_irq(&nullb->lock); 1143 while (n > 0) { 1144 temp = min_t(size_t, n, dev->blocksize); 1145 null_free_sector(nullb, sector, false); 1146 if (null_cache_active(nullb)) 1147 null_free_sector(nullb, sector, true); 1148 sector += temp >> SECTOR_SHIFT; 1149 n -= temp; 1150 } 1151 spin_unlock_irq(&nullb->lock); 1152 1153 return BLK_STS_OK; 1154 } 1155 1156 static int null_handle_flush(struct nullb *nullb) 1157 { 1158 int err; 1159 1160 if (!null_cache_active(nullb)) 1161 return 0; 1162 1163 spin_lock_irq(&nullb->lock); 1164 while (true) { 1165 err = null_make_cache_space(nullb, 1166 nullb->dev->cache_size * 1024 * 1024); 1167 if (err || nullb->dev->curr_cache == 0) 1168 break; 1169 } 1170 1171 WARN_ON(!radix_tree_empty(&nullb->dev->cache)); 1172 spin_unlock_irq(&nullb->lock); 1173 return err; 1174 } 1175 1176 static int null_transfer(struct nullb *nullb, struct page *page, 1177 unsigned int len, unsigned int off, bool is_write, sector_t sector, 1178 bool is_fua) 1179 { 1180 struct nullb_device *dev = nullb->dev; 1181 unsigned int valid_len = len; 1182 int err = 0; 1183 1184 if (!is_write) { 1185 if (dev->zoned) 1186 valid_len = null_zone_valid_read_len(nullb, 1187 sector, len); 1188 1189 if (valid_len) { 1190 err = copy_from_nullb(nullb, page, off, 1191 sector, valid_len); 1192 off += valid_len; 1193 len -= valid_len; 1194 } 1195 1196 if (len) 1197 nullb_fill_pattern(nullb, page, len, off); 1198 flush_dcache_page(page); 1199 } else { 1200 flush_dcache_page(page); 1201 err = copy_to_nullb(nullb, page, off, sector, len, is_fua); 1202 } 1203 1204 return err; 1205 } 1206 1207 static int null_handle_rq(struct nullb_cmd *cmd) 1208 { 1209 struct request *rq = cmd->rq; 1210 struct nullb *nullb = cmd->nq->dev->nullb; 1211 int err; 1212 unsigned int len; 1213 sector_t sector = blk_rq_pos(rq); 1214 struct req_iterator iter; 1215 struct bio_vec bvec; 1216 1217 spin_lock_irq(&nullb->lock); 1218 rq_for_each_segment(bvec, rq, iter) { 1219 len = bvec.bv_len; 1220 err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset, 1221 op_is_write(req_op(rq)), sector, 1222 rq->cmd_flags & REQ_FUA); 1223 if (err) { 1224 spin_unlock_irq(&nullb->lock); 1225 return err; 1226 } 1227 sector += len >> SECTOR_SHIFT; 1228 } 1229 spin_unlock_irq(&nullb->lock); 1230 1231 return 0; 1232 } 1233 1234 static int null_handle_bio(struct nullb_cmd *cmd) 1235 { 1236 struct bio *bio = cmd->bio; 1237 struct nullb *nullb = cmd->nq->dev->nullb; 1238 int err; 1239 unsigned int len; 1240 sector_t sector = bio->bi_iter.bi_sector; 1241 struct bio_vec bvec; 1242 struct bvec_iter iter; 1243 1244 spin_lock_irq(&nullb->lock); 1245 bio_for_each_segment(bvec, bio, iter) { 1246 len = bvec.bv_len; 1247 err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset, 1248 op_is_write(bio_op(bio)), sector, 1249 bio->bi_opf & REQ_FUA); 1250 if (err) { 1251 spin_unlock_irq(&nullb->lock); 1252 return err; 1253 } 1254 sector += len >> SECTOR_SHIFT; 1255 } 1256 spin_unlock_irq(&nullb->lock); 1257 return 0; 1258 } 1259 1260 static void null_stop_queue(struct nullb *nullb) 1261 { 1262 struct request_queue *q = nullb->q; 1263 1264 if (nullb->dev->queue_mode == NULL_Q_MQ) 1265 blk_mq_stop_hw_queues(q); 1266 } 1267 1268 static void null_restart_queue_async(struct nullb *nullb) 1269 { 1270 struct request_queue *q = nullb->q; 1271 1272 if (nullb->dev->queue_mode == NULL_Q_MQ) 1273 blk_mq_start_stopped_hw_queues(q, true); 1274 } 1275 1276 static inline blk_status_t null_handle_throttled(struct nullb_cmd *cmd) 1277 { 1278 struct nullb_device *dev = cmd->nq->dev; 1279 struct nullb *nullb = dev->nullb; 1280 blk_status_t sts = BLK_STS_OK; 1281 struct request *rq = cmd->rq; 1282 1283 if (!hrtimer_active(&nullb->bw_timer)) 1284 hrtimer_restart(&nullb->bw_timer); 1285 1286 if (atomic_long_sub_return(blk_rq_bytes(rq), &nullb->cur_bytes) < 0) { 1287 null_stop_queue(nullb); 1288 /* race with timer */ 1289 if (atomic_long_read(&nullb->cur_bytes) > 0) 1290 null_restart_queue_async(nullb); 1291 /* requeue request */ 1292 sts = BLK_STS_DEV_RESOURCE; 1293 } 1294 return sts; 1295 } 1296 1297 static inline blk_status_t null_handle_badblocks(struct nullb_cmd *cmd, 1298 sector_t sector, 1299 sector_t nr_sectors) 1300 { 1301 struct badblocks *bb = &cmd->nq->dev->badblocks; 1302 sector_t first_bad; 1303 int bad_sectors; 1304 1305 if (badblocks_check(bb, sector, nr_sectors, &first_bad, &bad_sectors)) 1306 return BLK_STS_IOERR; 1307 1308 return BLK_STS_OK; 1309 } 1310 1311 static inline blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd, 1312 enum req_opf op, 1313 sector_t sector, 1314 sector_t nr_sectors) 1315 { 1316 struct nullb_device *dev = cmd->nq->dev; 1317 int err; 1318 1319 if (op == REQ_OP_DISCARD) 1320 return null_handle_discard(dev, sector, nr_sectors); 1321 1322 if (dev->queue_mode == NULL_Q_BIO) 1323 err = null_handle_bio(cmd); 1324 else 1325 err = null_handle_rq(cmd); 1326 1327 return errno_to_blk_status(err); 1328 } 1329 1330 static void nullb_zero_read_cmd_buffer(struct nullb_cmd *cmd) 1331 { 1332 struct nullb_device *dev = cmd->nq->dev; 1333 struct bio *bio; 1334 1335 if (dev->memory_backed) 1336 return; 1337 1338 if (dev->queue_mode == NULL_Q_BIO && bio_op(cmd->bio) == REQ_OP_READ) { 1339 zero_fill_bio(cmd->bio); 1340 } else if (req_op(cmd->rq) == REQ_OP_READ) { 1341 __rq_for_each_bio(bio, cmd->rq) 1342 zero_fill_bio(bio); 1343 } 1344 } 1345 1346 static inline void nullb_complete_cmd(struct nullb_cmd *cmd) 1347 { 1348 /* 1349 * Since root privileges are required to configure the null_blk 1350 * driver, it is fine that this driver does not initialize the 1351 * data buffers of read commands. Zero-initialize these buffers 1352 * anyway if KMSAN is enabled to prevent that KMSAN complains 1353 * about null_blk not initializing read data buffers. 1354 */ 1355 if (IS_ENABLED(CONFIG_KMSAN)) 1356 nullb_zero_read_cmd_buffer(cmd); 1357 1358 /* Complete IO by inline, softirq or timer */ 1359 switch (cmd->nq->dev->irqmode) { 1360 case NULL_IRQ_SOFTIRQ: 1361 switch (cmd->nq->dev->queue_mode) { 1362 case NULL_Q_MQ: 1363 if (likely(!blk_should_fake_timeout(cmd->rq->q))) 1364 blk_mq_complete_request(cmd->rq); 1365 break; 1366 case NULL_Q_BIO: 1367 /* 1368 * XXX: no proper submitting cpu information available. 1369 */ 1370 end_cmd(cmd); 1371 break; 1372 } 1373 break; 1374 case NULL_IRQ_NONE: 1375 end_cmd(cmd); 1376 break; 1377 case NULL_IRQ_TIMER: 1378 null_cmd_end_timer(cmd); 1379 break; 1380 } 1381 } 1382 1383 blk_status_t null_process_cmd(struct nullb_cmd *cmd, 1384 enum req_opf op, sector_t sector, 1385 unsigned int nr_sectors) 1386 { 1387 struct nullb_device *dev = cmd->nq->dev; 1388 blk_status_t ret; 1389 1390 if (dev->badblocks.shift != -1) { 1391 ret = null_handle_badblocks(cmd, sector, nr_sectors); 1392 if (ret != BLK_STS_OK) 1393 return ret; 1394 } 1395 1396 if (dev->memory_backed) 1397 return null_handle_memory_backed(cmd, op, sector, nr_sectors); 1398 1399 return BLK_STS_OK; 1400 } 1401 1402 static blk_status_t null_handle_cmd(struct nullb_cmd *cmd, sector_t sector, 1403 sector_t nr_sectors, enum req_opf op) 1404 { 1405 struct nullb_device *dev = cmd->nq->dev; 1406 struct nullb *nullb = dev->nullb; 1407 blk_status_t sts; 1408 1409 if (test_bit(NULLB_DEV_FL_THROTTLED, &dev->flags)) { 1410 sts = null_handle_throttled(cmd); 1411 if (sts != BLK_STS_OK) 1412 return sts; 1413 } 1414 1415 if (op == REQ_OP_FLUSH) { 1416 cmd->error = errno_to_blk_status(null_handle_flush(nullb)); 1417 goto out; 1418 } 1419 1420 if (dev->zoned) 1421 sts = null_process_zoned_cmd(cmd, op, sector, nr_sectors); 1422 else 1423 sts = null_process_cmd(cmd, op, sector, nr_sectors); 1424 1425 /* Do not overwrite errors (e.g. timeout errors) */ 1426 if (cmd->error == BLK_STS_OK) 1427 cmd->error = sts; 1428 1429 out: 1430 nullb_complete_cmd(cmd); 1431 return BLK_STS_OK; 1432 } 1433 1434 static enum hrtimer_restart nullb_bwtimer_fn(struct hrtimer *timer) 1435 { 1436 struct nullb *nullb = container_of(timer, struct nullb, bw_timer); 1437 ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL); 1438 unsigned int mbps = nullb->dev->mbps; 1439 1440 if (atomic_long_read(&nullb->cur_bytes) == mb_per_tick(mbps)) 1441 return HRTIMER_NORESTART; 1442 1443 atomic_long_set(&nullb->cur_bytes, mb_per_tick(mbps)); 1444 null_restart_queue_async(nullb); 1445 1446 hrtimer_forward_now(&nullb->bw_timer, timer_interval); 1447 1448 return HRTIMER_RESTART; 1449 } 1450 1451 static void nullb_setup_bwtimer(struct nullb *nullb) 1452 { 1453 ktime_t timer_interval = ktime_set(0, TIMER_INTERVAL); 1454 1455 hrtimer_init(&nullb->bw_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1456 nullb->bw_timer.function = nullb_bwtimer_fn; 1457 atomic_long_set(&nullb->cur_bytes, mb_per_tick(nullb->dev->mbps)); 1458 hrtimer_start(&nullb->bw_timer, timer_interval, HRTIMER_MODE_REL); 1459 } 1460 1461 static struct nullb_queue *nullb_to_queue(struct nullb *nullb) 1462 { 1463 int index = 0; 1464 1465 if (nullb->nr_queues != 1) 1466 index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues); 1467 1468 return &nullb->queues[index]; 1469 } 1470 1471 static void null_submit_bio(struct bio *bio) 1472 { 1473 sector_t sector = bio->bi_iter.bi_sector; 1474 sector_t nr_sectors = bio_sectors(bio); 1475 struct nullb *nullb = bio->bi_bdev->bd_disk->private_data; 1476 struct nullb_queue *nq = nullb_to_queue(nullb); 1477 1478 null_handle_cmd(alloc_cmd(nq, bio), sector, nr_sectors, bio_op(bio)); 1479 } 1480 1481 static bool should_timeout_request(struct request *rq) 1482 { 1483 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 1484 if (g_timeout_str[0]) 1485 return should_fail(&null_timeout_attr, 1); 1486 #endif 1487 return false; 1488 } 1489 1490 static bool should_requeue_request(struct request *rq) 1491 { 1492 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 1493 if (g_requeue_str[0]) 1494 return should_fail(&null_requeue_attr, 1); 1495 #endif 1496 return false; 1497 } 1498 1499 static int null_map_queues(struct blk_mq_tag_set *set) 1500 { 1501 struct nullb *nullb = set->driver_data; 1502 int i, qoff; 1503 unsigned int submit_queues = g_submit_queues; 1504 unsigned int poll_queues = g_poll_queues; 1505 1506 if (nullb) { 1507 struct nullb_device *dev = nullb->dev; 1508 1509 /* 1510 * Refer nr_hw_queues of the tag set to check if the expected 1511 * number of hardware queues are prepared. If block layer failed 1512 * to prepare them, use previous numbers of submit queues and 1513 * poll queues to map queues. 1514 */ 1515 if (set->nr_hw_queues == 1516 dev->submit_queues + dev->poll_queues) { 1517 submit_queues = dev->submit_queues; 1518 poll_queues = dev->poll_queues; 1519 } else if (set->nr_hw_queues == 1520 dev->prev_submit_queues + dev->prev_poll_queues) { 1521 submit_queues = dev->prev_submit_queues; 1522 poll_queues = dev->prev_poll_queues; 1523 } else { 1524 pr_warn("tag set has unexpected nr_hw_queues: %d\n", 1525 set->nr_hw_queues); 1526 return -EINVAL; 1527 } 1528 } 1529 1530 for (i = 0, qoff = 0; i < set->nr_maps; i++) { 1531 struct blk_mq_queue_map *map = &set->map[i]; 1532 1533 switch (i) { 1534 case HCTX_TYPE_DEFAULT: 1535 map->nr_queues = submit_queues; 1536 break; 1537 case HCTX_TYPE_READ: 1538 map->nr_queues = 0; 1539 continue; 1540 case HCTX_TYPE_POLL: 1541 map->nr_queues = poll_queues; 1542 break; 1543 } 1544 map->queue_offset = qoff; 1545 qoff += map->nr_queues; 1546 blk_mq_map_queues(map); 1547 } 1548 1549 return 0; 1550 } 1551 1552 static int null_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1553 { 1554 struct nullb_queue *nq = hctx->driver_data; 1555 LIST_HEAD(list); 1556 int nr = 0; 1557 1558 spin_lock(&nq->poll_lock); 1559 list_splice_init(&nq->poll_list, &list); 1560 spin_unlock(&nq->poll_lock); 1561 1562 while (!list_empty(&list)) { 1563 struct nullb_cmd *cmd; 1564 struct request *req; 1565 1566 req = list_first_entry(&list, struct request, queuelist); 1567 list_del_init(&req->queuelist); 1568 cmd = blk_mq_rq_to_pdu(req); 1569 cmd->error = null_process_cmd(cmd, req_op(req), blk_rq_pos(req), 1570 blk_rq_sectors(req)); 1571 if (!blk_mq_add_to_batch(req, iob, (__force int) cmd->error, 1572 blk_mq_end_request_batch)) 1573 end_cmd(cmd); 1574 nr++; 1575 } 1576 1577 return nr; 1578 } 1579 1580 static enum blk_eh_timer_return null_timeout_rq(struct request *rq, bool res) 1581 { 1582 struct blk_mq_hw_ctx *hctx = rq->mq_hctx; 1583 struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq); 1584 1585 pr_info("rq %p timed out\n", rq); 1586 1587 if (hctx->type == HCTX_TYPE_POLL) { 1588 struct nullb_queue *nq = hctx->driver_data; 1589 1590 spin_lock(&nq->poll_lock); 1591 list_del_init(&rq->queuelist); 1592 spin_unlock(&nq->poll_lock); 1593 } 1594 1595 /* 1596 * If the device is marked as blocking (i.e. memory backed or zoned 1597 * device), the submission path may be blocked waiting for resources 1598 * and cause real timeouts. For these real timeouts, the submission 1599 * path will complete the request using blk_mq_complete_request(). 1600 * Only fake timeouts need to execute blk_mq_complete_request() here. 1601 */ 1602 cmd->error = BLK_STS_TIMEOUT; 1603 if (cmd->fake_timeout) 1604 blk_mq_complete_request(rq); 1605 return BLK_EH_DONE; 1606 } 1607 1608 static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx, 1609 const struct blk_mq_queue_data *bd) 1610 { 1611 struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); 1612 struct nullb_queue *nq = hctx->driver_data; 1613 sector_t nr_sectors = blk_rq_sectors(bd->rq); 1614 sector_t sector = blk_rq_pos(bd->rq); 1615 const bool is_poll = hctx->type == HCTX_TYPE_POLL; 1616 1617 might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); 1618 1619 if (!is_poll && nq->dev->irqmode == NULL_IRQ_TIMER) { 1620 hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); 1621 cmd->timer.function = null_cmd_timer_expired; 1622 } 1623 cmd->rq = bd->rq; 1624 cmd->error = BLK_STS_OK; 1625 cmd->nq = nq; 1626 cmd->fake_timeout = should_timeout_request(bd->rq); 1627 1628 blk_mq_start_request(bd->rq); 1629 1630 if (should_requeue_request(bd->rq)) { 1631 /* 1632 * Alternate between hitting the core BUSY path, and the 1633 * driver driven requeue path 1634 */ 1635 nq->requeue_selection++; 1636 if (nq->requeue_selection & 1) 1637 return BLK_STS_RESOURCE; 1638 else { 1639 blk_mq_requeue_request(bd->rq, true); 1640 return BLK_STS_OK; 1641 } 1642 } 1643 1644 if (is_poll) { 1645 spin_lock(&nq->poll_lock); 1646 list_add_tail(&bd->rq->queuelist, &nq->poll_list); 1647 spin_unlock(&nq->poll_lock); 1648 return BLK_STS_OK; 1649 } 1650 if (cmd->fake_timeout) 1651 return BLK_STS_OK; 1652 1653 return null_handle_cmd(cmd, sector, nr_sectors, req_op(bd->rq)); 1654 } 1655 1656 static void cleanup_queue(struct nullb_queue *nq) 1657 { 1658 kfree(nq->tag_map); 1659 kfree(nq->cmds); 1660 } 1661 1662 static void cleanup_queues(struct nullb *nullb) 1663 { 1664 int i; 1665 1666 for (i = 0; i < nullb->nr_queues; i++) 1667 cleanup_queue(&nullb->queues[i]); 1668 1669 kfree(nullb->queues); 1670 } 1671 1672 static void null_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) 1673 { 1674 struct nullb_queue *nq = hctx->driver_data; 1675 struct nullb *nullb = nq->dev->nullb; 1676 1677 nullb->nr_queues--; 1678 } 1679 1680 static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq) 1681 { 1682 init_waitqueue_head(&nq->wait); 1683 nq->queue_depth = nullb->queue_depth; 1684 nq->dev = nullb->dev; 1685 INIT_LIST_HEAD(&nq->poll_list); 1686 spin_lock_init(&nq->poll_lock); 1687 } 1688 1689 static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, 1690 unsigned int hctx_idx) 1691 { 1692 struct nullb *nullb = hctx->queue->queuedata; 1693 struct nullb_queue *nq; 1694 1695 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 1696 if (g_init_hctx_str[0] && should_fail(&null_init_hctx_attr, 1)) 1697 return -EFAULT; 1698 #endif 1699 1700 nq = &nullb->queues[hctx_idx]; 1701 hctx->driver_data = nq; 1702 null_init_queue(nullb, nq); 1703 nullb->nr_queues++; 1704 1705 return 0; 1706 } 1707 1708 static const struct blk_mq_ops null_mq_ops = { 1709 .queue_rq = null_queue_rq, 1710 .complete = null_complete_rq, 1711 .timeout = null_timeout_rq, 1712 .poll = null_poll, 1713 .map_queues = null_map_queues, 1714 .init_hctx = null_init_hctx, 1715 .exit_hctx = null_exit_hctx, 1716 }; 1717 1718 static void null_del_dev(struct nullb *nullb) 1719 { 1720 struct nullb_device *dev; 1721 1722 if (!nullb) 1723 return; 1724 1725 dev = nullb->dev; 1726 1727 ida_simple_remove(&nullb_indexes, nullb->index); 1728 1729 list_del_init(&nullb->list); 1730 1731 del_gendisk(nullb->disk); 1732 1733 if (test_bit(NULLB_DEV_FL_THROTTLED, &nullb->dev->flags)) { 1734 hrtimer_cancel(&nullb->bw_timer); 1735 atomic_long_set(&nullb->cur_bytes, LONG_MAX); 1736 null_restart_queue_async(nullb); 1737 } 1738 1739 blk_cleanup_disk(nullb->disk); 1740 if (dev->queue_mode == NULL_Q_MQ && 1741 nullb->tag_set == &nullb->__tag_set) 1742 blk_mq_free_tag_set(nullb->tag_set); 1743 cleanup_queues(nullb); 1744 if (null_cache_active(nullb)) 1745 null_free_device_storage(nullb->dev, true); 1746 kfree(nullb); 1747 dev->nullb = NULL; 1748 } 1749 1750 static void null_config_discard(struct nullb *nullb) 1751 { 1752 if (nullb->dev->discard == false) 1753 return; 1754 1755 if (!nullb->dev->memory_backed) { 1756 nullb->dev->discard = false; 1757 pr_info("discard option is ignored without memory backing\n"); 1758 return; 1759 } 1760 1761 if (nullb->dev->zoned) { 1762 nullb->dev->discard = false; 1763 pr_info("discard option is ignored in zoned mode\n"); 1764 return; 1765 } 1766 1767 nullb->q->limits.discard_granularity = nullb->dev->blocksize; 1768 nullb->q->limits.discard_alignment = nullb->dev->blocksize; 1769 blk_queue_max_discard_sectors(nullb->q, UINT_MAX >> 9); 1770 blk_queue_flag_set(QUEUE_FLAG_DISCARD, nullb->q); 1771 } 1772 1773 static const struct block_device_operations null_bio_ops = { 1774 .owner = THIS_MODULE, 1775 .submit_bio = null_submit_bio, 1776 .report_zones = null_report_zones, 1777 }; 1778 1779 static const struct block_device_operations null_rq_ops = { 1780 .owner = THIS_MODULE, 1781 .report_zones = null_report_zones, 1782 }; 1783 1784 static int setup_commands(struct nullb_queue *nq) 1785 { 1786 struct nullb_cmd *cmd; 1787 int i, tag_size; 1788 1789 nq->cmds = kcalloc(nq->queue_depth, sizeof(*cmd), GFP_KERNEL); 1790 if (!nq->cmds) 1791 return -ENOMEM; 1792 1793 tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG; 1794 nq->tag_map = kcalloc(tag_size, sizeof(unsigned long), GFP_KERNEL); 1795 if (!nq->tag_map) { 1796 kfree(nq->cmds); 1797 return -ENOMEM; 1798 } 1799 1800 for (i = 0; i < nq->queue_depth; i++) { 1801 cmd = &nq->cmds[i]; 1802 cmd->tag = -1U; 1803 } 1804 1805 return 0; 1806 } 1807 1808 static int setup_queues(struct nullb *nullb) 1809 { 1810 int nqueues = nr_cpu_ids; 1811 1812 if (g_poll_queues) 1813 nqueues += g_poll_queues; 1814 1815 nullb->queues = kcalloc(nqueues, sizeof(struct nullb_queue), 1816 GFP_KERNEL); 1817 if (!nullb->queues) 1818 return -ENOMEM; 1819 1820 nullb->queue_depth = nullb->dev->hw_queue_depth; 1821 return 0; 1822 } 1823 1824 static int init_driver_queues(struct nullb *nullb) 1825 { 1826 struct nullb_queue *nq; 1827 int i, ret = 0; 1828 1829 for (i = 0; i < nullb->dev->submit_queues; i++) { 1830 nq = &nullb->queues[i]; 1831 1832 null_init_queue(nullb, nq); 1833 1834 ret = setup_commands(nq); 1835 if (ret) 1836 return ret; 1837 nullb->nr_queues++; 1838 } 1839 return 0; 1840 } 1841 1842 static int null_gendisk_register(struct nullb *nullb) 1843 { 1844 sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT; 1845 struct gendisk *disk = nullb->disk; 1846 1847 set_capacity(disk, size); 1848 1849 disk->major = null_major; 1850 disk->first_minor = nullb->index; 1851 disk->minors = 1; 1852 if (queue_is_mq(nullb->q)) 1853 disk->fops = &null_rq_ops; 1854 else 1855 disk->fops = &null_bio_ops; 1856 disk->private_data = nullb; 1857 strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN); 1858 1859 if (nullb->dev->zoned) { 1860 int ret = null_register_zoned_dev(nullb); 1861 1862 if (ret) 1863 return ret; 1864 } 1865 1866 return add_disk(disk); 1867 } 1868 1869 static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set) 1870 { 1871 int poll_queues; 1872 1873 set->ops = &null_mq_ops; 1874 set->nr_hw_queues = nullb ? nullb->dev->submit_queues : 1875 g_submit_queues; 1876 poll_queues = nullb ? nullb->dev->poll_queues : g_poll_queues; 1877 if (poll_queues) 1878 set->nr_hw_queues += poll_queues; 1879 set->queue_depth = nullb ? nullb->dev->hw_queue_depth : 1880 g_hw_queue_depth; 1881 set->numa_node = nullb ? nullb->dev->home_node : g_home_node; 1882 set->cmd_size = sizeof(struct nullb_cmd); 1883 set->flags = BLK_MQ_F_SHOULD_MERGE; 1884 if (g_no_sched) 1885 set->flags |= BLK_MQ_F_NO_SCHED; 1886 if (g_shared_tag_bitmap) 1887 set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; 1888 set->driver_data = nullb; 1889 if (poll_queues) 1890 set->nr_maps = 3; 1891 else 1892 set->nr_maps = 1; 1893 1894 if ((nullb && nullb->dev->blocking) || g_blocking) 1895 set->flags |= BLK_MQ_F_BLOCKING; 1896 1897 return blk_mq_alloc_tag_set(set); 1898 } 1899 1900 static int null_validate_conf(struct nullb_device *dev) 1901 { 1902 dev->blocksize = round_down(dev->blocksize, 512); 1903 dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096); 1904 1905 if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) { 1906 if (dev->submit_queues != nr_online_nodes) 1907 dev->submit_queues = nr_online_nodes; 1908 } else if (dev->submit_queues > nr_cpu_ids) 1909 dev->submit_queues = nr_cpu_ids; 1910 else if (dev->submit_queues == 0) 1911 dev->submit_queues = 1; 1912 dev->prev_submit_queues = dev->submit_queues; 1913 1914 if (dev->poll_queues > g_poll_queues) 1915 dev->poll_queues = g_poll_queues; 1916 dev->prev_poll_queues = dev->poll_queues; 1917 1918 dev->queue_mode = min_t(unsigned int, dev->queue_mode, NULL_Q_MQ); 1919 dev->irqmode = min_t(unsigned int, dev->irqmode, NULL_IRQ_TIMER); 1920 1921 /* Do memory allocation, so set blocking */ 1922 if (dev->memory_backed) 1923 dev->blocking = true; 1924 else /* cache is meaningless */ 1925 dev->cache_size = 0; 1926 dev->cache_size = min_t(unsigned long, ULONG_MAX / 1024 / 1024, 1927 dev->cache_size); 1928 dev->mbps = min_t(unsigned int, 1024 * 40, dev->mbps); 1929 /* can not stop a queue */ 1930 if (dev->queue_mode == NULL_Q_BIO) 1931 dev->mbps = 0; 1932 1933 if (dev->zoned && 1934 (!dev->zone_size || !is_power_of_2(dev->zone_size))) { 1935 pr_err("zone_size must be power-of-two\n"); 1936 return -EINVAL; 1937 } 1938 1939 return 0; 1940 } 1941 1942 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 1943 static bool __null_setup_fault(struct fault_attr *attr, char *str) 1944 { 1945 if (!str[0]) 1946 return true; 1947 1948 if (!setup_fault_attr(attr, str)) 1949 return false; 1950 1951 attr->verbose = 0; 1952 return true; 1953 } 1954 #endif 1955 1956 static bool null_setup_fault(void) 1957 { 1958 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION 1959 if (!__null_setup_fault(&null_timeout_attr, g_timeout_str)) 1960 return false; 1961 if (!__null_setup_fault(&null_requeue_attr, g_requeue_str)) 1962 return false; 1963 if (!__null_setup_fault(&null_init_hctx_attr, g_init_hctx_str)) 1964 return false; 1965 #endif 1966 return true; 1967 } 1968 1969 static int null_add_dev(struct nullb_device *dev) 1970 { 1971 struct nullb *nullb; 1972 int rv; 1973 1974 rv = null_validate_conf(dev); 1975 if (rv) 1976 return rv; 1977 1978 nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node); 1979 if (!nullb) { 1980 rv = -ENOMEM; 1981 goto out; 1982 } 1983 nullb->dev = dev; 1984 dev->nullb = nullb; 1985 1986 spin_lock_init(&nullb->lock); 1987 1988 rv = setup_queues(nullb); 1989 if (rv) 1990 goto out_free_nullb; 1991 1992 if (dev->queue_mode == NULL_Q_MQ) { 1993 if (shared_tags) { 1994 nullb->tag_set = &tag_set; 1995 rv = 0; 1996 } else { 1997 nullb->tag_set = &nullb->__tag_set; 1998 rv = null_init_tag_set(nullb, nullb->tag_set); 1999 } 2000 2001 if (rv) 2002 goto out_cleanup_queues; 2003 2004 if (!null_setup_fault()) 2005 goto out_cleanup_tags; 2006 2007 nullb->tag_set->timeout = 5 * HZ; 2008 nullb->disk = blk_mq_alloc_disk(nullb->tag_set, nullb); 2009 if (IS_ERR(nullb->disk)) { 2010 rv = PTR_ERR(nullb->disk); 2011 goto out_cleanup_tags; 2012 } 2013 nullb->q = nullb->disk->queue; 2014 } else if (dev->queue_mode == NULL_Q_BIO) { 2015 rv = -ENOMEM; 2016 nullb->disk = blk_alloc_disk(nullb->dev->home_node); 2017 if (!nullb->disk) 2018 goto out_cleanup_queues; 2019 2020 nullb->q = nullb->disk->queue; 2021 rv = init_driver_queues(nullb); 2022 if (rv) 2023 goto out_cleanup_disk; 2024 } 2025 2026 if (dev->mbps) { 2027 set_bit(NULLB_DEV_FL_THROTTLED, &dev->flags); 2028 nullb_setup_bwtimer(nullb); 2029 } 2030 2031 if (dev->cache_size > 0) { 2032 set_bit(NULLB_DEV_FL_CACHE, &nullb->dev->flags); 2033 blk_queue_write_cache(nullb->q, true, true); 2034 } 2035 2036 if (dev->zoned) { 2037 rv = null_init_zoned_dev(dev, nullb->q); 2038 if (rv) 2039 goto out_cleanup_disk; 2040 } 2041 2042 nullb->q->queuedata = nullb; 2043 blk_queue_flag_set(QUEUE_FLAG_NONROT, nullb->q); 2044 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, nullb->q); 2045 2046 mutex_lock(&lock); 2047 nullb->index = ida_simple_get(&nullb_indexes, 0, 0, GFP_KERNEL); 2048 dev->index = nullb->index; 2049 mutex_unlock(&lock); 2050 2051 blk_queue_logical_block_size(nullb->q, dev->blocksize); 2052 blk_queue_physical_block_size(nullb->q, dev->blocksize); 2053 if (!dev->max_sectors) 2054 dev->max_sectors = queue_max_hw_sectors(nullb->q); 2055 dev->max_sectors = min_t(unsigned int, dev->max_sectors, 2056 BLK_DEF_MAX_SECTORS); 2057 blk_queue_max_hw_sectors(nullb->q, dev->max_sectors); 2058 2059 if (dev->virt_boundary) 2060 blk_queue_virt_boundary(nullb->q, PAGE_SIZE - 1); 2061 2062 null_config_discard(nullb); 2063 2064 sprintf(nullb->disk_name, "nullb%d", nullb->index); 2065 2066 rv = null_gendisk_register(nullb); 2067 if (rv) 2068 goto out_cleanup_zone; 2069 2070 mutex_lock(&lock); 2071 list_add_tail(&nullb->list, &nullb_list); 2072 mutex_unlock(&lock); 2073 2074 return 0; 2075 out_cleanup_zone: 2076 null_free_zoned_dev(dev); 2077 out_cleanup_disk: 2078 blk_cleanup_disk(nullb->disk); 2079 out_cleanup_tags: 2080 if (dev->queue_mode == NULL_Q_MQ && nullb->tag_set == &nullb->__tag_set) 2081 blk_mq_free_tag_set(nullb->tag_set); 2082 out_cleanup_queues: 2083 cleanup_queues(nullb); 2084 out_free_nullb: 2085 kfree(nullb); 2086 dev->nullb = NULL; 2087 out: 2088 return rv; 2089 } 2090 2091 static int __init null_init(void) 2092 { 2093 int ret = 0; 2094 unsigned int i; 2095 struct nullb *nullb; 2096 struct nullb_device *dev; 2097 2098 if (g_bs > PAGE_SIZE) { 2099 pr_warn("invalid block size\n"); 2100 pr_warn("defaults block size to %lu\n", PAGE_SIZE); 2101 g_bs = PAGE_SIZE; 2102 } 2103 2104 if (g_max_sectors > BLK_DEF_MAX_SECTORS) { 2105 pr_warn("invalid max sectors\n"); 2106 pr_warn("defaults max sectors to %u\n", BLK_DEF_MAX_SECTORS); 2107 g_max_sectors = BLK_DEF_MAX_SECTORS; 2108 } 2109 2110 if (g_home_node != NUMA_NO_NODE && g_home_node >= nr_online_nodes) { 2111 pr_err("invalid home_node value\n"); 2112 g_home_node = NUMA_NO_NODE; 2113 } 2114 2115 if (g_queue_mode == NULL_Q_RQ) { 2116 pr_err("legacy IO path no longer available\n"); 2117 return -EINVAL; 2118 } 2119 if (g_queue_mode == NULL_Q_MQ && g_use_per_node_hctx) { 2120 if (g_submit_queues != nr_online_nodes) { 2121 pr_warn("submit_queues param is set to %u.\n", 2122 nr_online_nodes); 2123 g_submit_queues = nr_online_nodes; 2124 } 2125 } else if (g_submit_queues > nr_cpu_ids) 2126 g_submit_queues = nr_cpu_ids; 2127 else if (g_submit_queues <= 0) 2128 g_submit_queues = 1; 2129 2130 if (g_queue_mode == NULL_Q_MQ && shared_tags) { 2131 ret = null_init_tag_set(NULL, &tag_set); 2132 if (ret) 2133 return ret; 2134 } 2135 2136 config_group_init(&nullb_subsys.su_group); 2137 mutex_init(&nullb_subsys.su_mutex); 2138 2139 ret = configfs_register_subsystem(&nullb_subsys); 2140 if (ret) 2141 goto err_tagset; 2142 2143 mutex_init(&lock); 2144 2145 null_major = register_blkdev(0, "nullb"); 2146 if (null_major < 0) { 2147 ret = null_major; 2148 goto err_conf; 2149 } 2150 2151 for (i = 0; i < nr_devices; i++) { 2152 dev = null_alloc_dev(); 2153 if (!dev) { 2154 ret = -ENOMEM; 2155 goto err_dev; 2156 } 2157 ret = null_add_dev(dev); 2158 if (ret) { 2159 null_free_dev(dev); 2160 goto err_dev; 2161 } 2162 } 2163 2164 pr_info("module loaded\n"); 2165 return 0; 2166 2167 err_dev: 2168 while (!list_empty(&nullb_list)) { 2169 nullb = list_entry(nullb_list.next, struct nullb, list); 2170 dev = nullb->dev; 2171 null_del_dev(nullb); 2172 null_free_dev(dev); 2173 } 2174 unregister_blkdev(null_major, "nullb"); 2175 err_conf: 2176 configfs_unregister_subsystem(&nullb_subsys); 2177 err_tagset: 2178 if (g_queue_mode == NULL_Q_MQ && shared_tags) 2179 blk_mq_free_tag_set(&tag_set); 2180 return ret; 2181 } 2182 2183 static void __exit null_exit(void) 2184 { 2185 struct nullb *nullb; 2186 2187 configfs_unregister_subsystem(&nullb_subsys); 2188 2189 unregister_blkdev(null_major, "nullb"); 2190 2191 mutex_lock(&lock); 2192 while (!list_empty(&nullb_list)) { 2193 struct nullb_device *dev; 2194 2195 nullb = list_entry(nullb_list.next, struct nullb, list); 2196 dev = nullb->dev; 2197 null_del_dev(nullb); 2198 null_free_dev(dev); 2199 } 2200 mutex_unlock(&lock); 2201 2202 if (g_queue_mode == NULL_Q_MQ && shared_tags) 2203 blk_mq_free_tag_set(&tag_set); 2204 } 2205 2206 module_init(null_init); 2207 module_exit(null_exit); 2208 2209 MODULE_AUTHOR("Jens Axboe <axboe@kernel.dk>"); 2210 MODULE_LICENSE("GPL"); 2211