1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * gendisk handling 4 * 5 * Portions Copyright (C) 2020 Christoph Hellwig 6 */ 7 8 #include <linux/module.h> 9 #include <linux/ctype.h> 10 #include <linux/fs.h> 11 #include <linux/kdev_t.h> 12 #include <linux/kernel.h> 13 #include <linux/blkdev.h> 14 #include <linux/backing-dev.h> 15 #include <linux/init.h> 16 #include <linux/spinlock.h> 17 #include <linux/proc_fs.h> 18 #include <linux/seq_file.h> 19 #include <linux/slab.h> 20 #include <linux/kmod.h> 21 #include <linux/major.h> 22 #include <linux/mutex.h> 23 #include <linux/idr.h> 24 #include <linux/log2.h> 25 #include <linux/pm_runtime.h> 26 #include <linux/badblocks.h> 27 #include <linux/part_stat.h> 28 #include <linux/blktrace_api.h> 29 30 #include "blk-throttle.h" 31 #include "blk.h" 32 #include "blk-mq-sched.h" 33 #include "blk-rq-qos.h" 34 #include "blk-cgroup.h" 35 36 static struct kobject *block_depr; 37 38 /* 39 * Unique, monotonically increasing sequential number associated with block 40 * devices instances (i.e. incremented each time a device is attached). 41 * Associating uevents with block devices in userspace is difficult and racy: 42 * the uevent netlink socket is lossy, and on slow and overloaded systems has 43 * a very high latency. 44 * Block devices do not have exclusive owners in userspace, any process can set 45 * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0 46 * can be reused again and again). 47 * A userspace process setting up a block device and watching for its events 48 * cannot thus reliably tell whether an event relates to the device it just set 49 * up or another earlier instance with the same name. 50 * This sequential number allows userspace processes to solve this problem, and 51 * uniquely associate an uevent to the lifetime to a device. 52 */ 53 static atomic64_t diskseq; 54 55 /* for extended dynamic devt allocation, currently only one major is used */ 56 #define NR_EXT_DEVT (1 << MINORBITS) 57 static DEFINE_IDA(ext_devt_ida); 58 59 void set_capacity(struct gendisk *disk, sector_t sectors) 60 { 61 bdev_set_nr_sectors(disk->part0, sectors); 62 } 63 EXPORT_SYMBOL(set_capacity); 64 65 /* 66 * Set disk capacity and notify if the size is not currently zero and will not 67 * be set to zero. Returns true if a uevent was sent, otherwise false. 68 */ 69 bool set_capacity_and_notify(struct gendisk *disk, sector_t size) 70 { 71 sector_t capacity = get_capacity(disk); 72 char *envp[] = { "RESIZE=1", NULL }; 73 74 set_capacity(disk, size); 75 76 /* 77 * Only print a message and send a uevent if the gendisk is user visible 78 * and alive. This avoids spamming the log and udev when setting the 79 * initial capacity during probing. 80 */ 81 if (size == capacity || 82 !disk_live(disk) || 83 (disk->flags & GENHD_FL_HIDDEN)) 84 return false; 85 86 pr_info("%s: detected capacity change from %lld to %lld\n", 87 disk->disk_name, capacity, size); 88 89 /* 90 * Historically we did not send a uevent for changes to/from an empty 91 * device. 92 */ 93 if (!capacity || !size) 94 return false; 95 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); 96 return true; 97 } 98 EXPORT_SYMBOL_GPL(set_capacity_and_notify); 99 100 static void part_stat_read_all(struct block_device *part, 101 struct disk_stats *stat) 102 { 103 int cpu; 104 105 memset(stat, 0, sizeof(struct disk_stats)); 106 for_each_possible_cpu(cpu) { 107 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu); 108 int group; 109 110 for (group = 0; group < NR_STAT_GROUPS; group++) { 111 stat->nsecs[group] += ptr->nsecs[group]; 112 stat->sectors[group] += ptr->sectors[group]; 113 stat->ios[group] += ptr->ios[group]; 114 stat->merges[group] += ptr->merges[group]; 115 } 116 117 stat->io_ticks += ptr->io_ticks; 118 } 119 } 120 121 static unsigned int part_in_flight(struct block_device *part) 122 { 123 unsigned int inflight = 0; 124 int cpu; 125 126 for_each_possible_cpu(cpu) { 127 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) + 128 part_stat_local_read_cpu(part, in_flight[1], cpu); 129 } 130 if ((int)inflight < 0) 131 inflight = 0; 132 133 return inflight; 134 } 135 136 static void part_in_flight_rw(struct block_device *part, 137 unsigned int inflight[2]) 138 { 139 int cpu; 140 141 inflight[0] = 0; 142 inflight[1] = 0; 143 for_each_possible_cpu(cpu) { 144 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu); 145 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu); 146 } 147 if ((int)inflight[0] < 0) 148 inflight[0] = 0; 149 if ((int)inflight[1] < 0) 150 inflight[1] = 0; 151 } 152 153 /* 154 * Can be deleted altogether. Later. 155 * 156 */ 157 #define BLKDEV_MAJOR_HASH_SIZE 255 158 static struct blk_major_name { 159 struct blk_major_name *next; 160 int major; 161 char name[16]; 162 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD 163 void (*probe)(dev_t devt); 164 #endif 165 } *major_names[BLKDEV_MAJOR_HASH_SIZE]; 166 static DEFINE_MUTEX(major_names_lock); 167 static DEFINE_SPINLOCK(major_names_spinlock); 168 169 /* index in the above - for now: assume no multimajor ranges */ 170 static inline int major_to_index(unsigned major) 171 { 172 return major % BLKDEV_MAJOR_HASH_SIZE; 173 } 174 175 #ifdef CONFIG_PROC_FS 176 void blkdev_show(struct seq_file *seqf, off_t offset) 177 { 178 struct blk_major_name *dp; 179 180 spin_lock(&major_names_spinlock); 181 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next) 182 if (dp->major == offset) 183 seq_printf(seqf, "%3d %s\n", dp->major, dp->name); 184 spin_unlock(&major_names_spinlock); 185 } 186 #endif /* CONFIG_PROC_FS */ 187 188 /** 189 * __register_blkdev - register a new block device 190 * 191 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If 192 * @major = 0, try to allocate any unused major number. 193 * @name: the name of the new block device as a zero terminated string 194 * @probe: pre-devtmpfs / pre-udev callback used to create disks when their 195 * pre-created device node is accessed. When a probe call uses 196 * add_disk() and it fails the driver must cleanup resources. This 197 * interface may soon be removed. 198 * 199 * The @name must be unique within the system. 200 * 201 * The return value depends on the @major input parameter: 202 * 203 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1] 204 * then the function returns zero on success, or a negative error code 205 * - if any unused major number was requested with @major = 0 parameter 206 * then the return value is the allocated major number in range 207 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise 208 * 209 * See Documentation/admin-guide/devices.txt for the list of allocated 210 * major numbers. 211 * 212 * Use register_blkdev instead for any new code. 213 */ 214 int __register_blkdev(unsigned int major, const char *name, 215 void (*probe)(dev_t devt)) 216 { 217 struct blk_major_name **n, *p; 218 int index, ret = 0; 219 220 mutex_lock(&major_names_lock); 221 222 /* temporary */ 223 if (major == 0) { 224 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { 225 if (major_names[index] == NULL) 226 break; 227 } 228 229 if (index == 0) { 230 printk("%s: failed to get major for %s\n", 231 __func__, name); 232 ret = -EBUSY; 233 goto out; 234 } 235 major = index; 236 ret = major; 237 } 238 239 if (major >= BLKDEV_MAJOR_MAX) { 240 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n", 241 __func__, major, BLKDEV_MAJOR_MAX-1, name); 242 243 ret = -EINVAL; 244 goto out; 245 } 246 247 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); 248 if (p == NULL) { 249 ret = -ENOMEM; 250 goto out; 251 } 252 253 p->major = major; 254 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD 255 p->probe = probe; 256 #endif 257 strscpy(p->name, name, sizeof(p->name)); 258 p->next = NULL; 259 index = major_to_index(major); 260 261 spin_lock(&major_names_spinlock); 262 for (n = &major_names[index]; *n; n = &(*n)->next) { 263 if ((*n)->major == major) 264 break; 265 } 266 if (!*n) 267 *n = p; 268 else 269 ret = -EBUSY; 270 spin_unlock(&major_names_spinlock); 271 272 if (ret < 0) { 273 printk("register_blkdev: cannot get major %u for %s\n", 274 major, name); 275 kfree(p); 276 } 277 out: 278 mutex_unlock(&major_names_lock); 279 return ret; 280 } 281 EXPORT_SYMBOL(__register_blkdev); 282 283 void unregister_blkdev(unsigned int major, const char *name) 284 { 285 struct blk_major_name **n; 286 struct blk_major_name *p = NULL; 287 int index = major_to_index(major); 288 289 mutex_lock(&major_names_lock); 290 spin_lock(&major_names_spinlock); 291 for (n = &major_names[index]; *n; n = &(*n)->next) 292 if ((*n)->major == major) 293 break; 294 if (!*n || strcmp((*n)->name, name)) { 295 WARN_ON(1); 296 } else { 297 p = *n; 298 *n = p->next; 299 } 300 spin_unlock(&major_names_spinlock); 301 mutex_unlock(&major_names_lock); 302 kfree(p); 303 } 304 305 EXPORT_SYMBOL(unregister_blkdev); 306 307 int blk_alloc_ext_minor(void) 308 { 309 int idx; 310 311 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT - 1, GFP_KERNEL); 312 if (idx == -ENOSPC) 313 return -EBUSY; 314 return idx; 315 } 316 317 void blk_free_ext_minor(unsigned int minor) 318 { 319 ida_free(&ext_devt_ida, minor); 320 } 321 322 void disk_uevent(struct gendisk *disk, enum kobject_action action) 323 { 324 struct block_device *part; 325 unsigned long idx; 326 327 rcu_read_lock(); 328 xa_for_each(&disk->part_tbl, idx, part) { 329 if (bdev_is_partition(part) && !bdev_nr_sectors(part)) 330 continue; 331 if (!kobject_get_unless_zero(&part->bd_device.kobj)) 332 continue; 333 334 rcu_read_unlock(); 335 kobject_uevent(bdev_kobj(part), action); 336 put_device(&part->bd_device); 337 rcu_read_lock(); 338 } 339 rcu_read_unlock(); 340 } 341 EXPORT_SYMBOL_GPL(disk_uevent); 342 343 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode) 344 { 345 struct bdev_handle *handle; 346 int ret = 0; 347 348 if (disk->flags & (GENHD_FL_NO_PART | GENHD_FL_HIDDEN)) 349 return -EINVAL; 350 if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) 351 return -EINVAL; 352 if (disk->open_partitions) 353 return -EBUSY; 354 355 /* 356 * If the device is opened exclusively by current thread already, it's 357 * safe to scan partitons, otherwise, use bd_prepare_to_claim() to 358 * synchronize with other exclusive openers and other partition 359 * scanners. 360 */ 361 if (!(mode & BLK_OPEN_EXCL)) { 362 ret = bd_prepare_to_claim(disk->part0, disk_scan_partitions, 363 NULL); 364 if (ret) 365 return ret; 366 } 367 368 set_bit(GD_NEED_PART_SCAN, &disk->state); 369 handle = bdev_open_by_dev(disk_devt(disk), mode & ~BLK_OPEN_EXCL, NULL, 370 NULL); 371 if (IS_ERR(handle)) 372 ret = PTR_ERR(handle); 373 else 374 bdev_release(handle); 375 376 /* 377 * If blkdev_get_by_dev() failed early, GD_NEED_PART_SCAN is still set, 378 * and this will cause that re-assemble partitioned raid device will 379 * creat partition for underlying disk. 380 */ 381 clear_bit(GD_NEED_PART_SCAN, &disk->state); 382 if (!(mode & BLK_OPEN_EXCL)) 383 bd_abort_claiming(disk->part0, disk_scan_partitions); 384 return ret; 385 } 386 387 /** 388 * device_add_disk - add disk information to kernel list 389 * @parent: parent device for the disk 390 * @disk: per-device partitioning information 391 * @groups: Additional per-device sysfs groups 392 * 393 * This function registers the partitioning information in @disk 394 * with the kernel. 395 */ 396 int __must_check device_add_disk(struct device *parent, struct gendisk *disk, 397 const struct attribute_group **groups) 398 399 { 400 struct device *ddev = disk_to_dev(disk); 401 int ret; 402 403 /* Only makes sense for bio-based to set ->poll_bio */ 404 if (queue_is_mq(disk->queue) && disk->fops->poll_bio) 405 return -EINVAL; 406 407 /* 408 * The disk queue should now be all set with enough information about 409 * the device for the elevator code to pick an adequate default 410 * elevator if one is needed, that is, for devices requesting queue 411 * registration. 412 */ 413 elevator_init_mq(disk->queue); 414 415 /* Mark bdev as having a submit_bio, if needed */ 416 disk->part0->bd_has_submit_bio = disk->fops->submit_bio != NULL; 417 418 /* 419 * If the driver provides an explicit major number it also must provide 420 * the number of minors numbers supported, and those will be used to 421 * setup the gendisk. 422 * Otherwise just allocate the device numbers for both the whole device 423 * and all partitions from the extended dev_t space. 424 */ 425 ret = -EINVAL; 426 if (disk->major) { 427 if (WARN_ON(!disk->minors)) 428 goto out_exit_elevator; 429 430 if (disk->minors > DISK_MAX_PARTS) { 431 pr_err("block: can't allocate more than %d partitions\n", 432 DISK_MAX_PARTS); 433 disk->minors = DISK_MAX_PARTS; 434 } 435 if (disk->first_minor + disk->minors > MINORMASK + 1) 436 goto out_exit_elevator; 437 } else { 438 if (WARN_ON(disk->minors)) 439 goto out_exit_elevator; 440 441 ret = blk_alloc_ext_minor(); 442 if (ret < 0) 443 goto out_exit_elevator; 444 disk->major = BLOCK_EXT_MAJOR; 445 disk->first_minor = ret; 446 } 447 448 /* delay uevents, until we scanned partition table */ 449 dev_set_uevent_suppress(ddev, 1); 450 451 ddev->parent = parent; 452 ddev->groups = groups; 453 dev_set_name(ddev, "%s", disk->disk_name); 454 if (!(disk->flags & GENHD_FL_HIDDEN)) 455 ddev->devt = MKDEV(disk->major, disk->first_minor); 456 ret = device_add(ddev); 457 if (ret) 458 goto out_free_ext_minor; 459 460 ret = disk_alloc_events(disk); 461 if (ret) 462 goto out_device_del; 463 464 ret = sysfs_create_link(block_depr, &ddev->kobj, 465 kobject_name(&ddev->kobj)); 466 if (ret) 467 goto out_device_del; 468 469 /* 470 * avoid probable deadlock caused by allocating memory with 471 * GFP_KERNEL in runtime_resume callback of its all ancestor 472 * devices 473 */ 474 pm_runtime_set_memalloc_noio(ddev, true); 475 476 disk->part0->bd_holder_dir = 477 kobject_create_and_add("holders", &ddev->kobj); 478 if (!disk->part0->bd_holder_dir) { 479 ret = -ENOMEM; 480 goto out_del_block_link; 481 } 482 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); 483 if (!disk->slave_dir) { 484 ret = -ENOMEM; 485 goto out_put_holder_dir; 486 } 487 488 ret = blk_register_queue(disk); 489 if (ret) 490 goto out_put_slave_dir; 491 492 if (!(disk->flags & GENHD_FL_HIDDEN)) { 493 ret = bdi_register(disk->bdi, "%u:%u", 494 disk->major, disk->first_minor); 495 if (ret) 496 goto out_unregister_queue; 497 bdi_set_owner(disk->bdi, ddev); 498 ret = sysfs_create_link(&ddev->kobj, 499 &disk->bdi->dev->kobj, "bdi"); 500 if (ret) 501 goto out_unregister_bdi; 502 503 /* Make sure the first partition scan will be proceed */ 504 if (get_capacity(disk) && !(disk->flags & GENHD_FL_NO_PART) && 505 !test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) 506 set_bit(GD_NEED_PART_SCAN, &disk->state); 507 508 bdev_add(disk->part0, ddev->devt); 509 if (get_capacity(disk)) 510 disk_scan_partitions(disk, BLK_OPEN_READ); 511 512 /* 513 * Announce the disk and partitions after all partitions are 514 * created. (for hidden disks uevents remain suppressed forever) 515 */ 516 dev_set_uevent_suppress(ddev, 0); 517 disk_uevent(disk, KOBJ_ADD); 518 } else { 519 /* 520 * Even if the block_device for a hidden gendisk is not 521 * registered, it needs to have a valid bd_dev so that the 522 * freeing of the dynamic major works. 523 */ 524 disk->part0->bd_dev = MKDEV(disk->major, disk->first_minor); 525 } 526 527 disk_update_readahead(disk); 528 disk_add_events(disk); 529 set_bit(GD_ADDED, &disk->state); 530 return 0; 531 532 out_unregister_bdi: 533 if (!(disk->flags & GENHD_FL_HIDDEN)) 534 bdi_unregister(disk->bdi); 535 out_unregister_queue: 536 blk_unregister_queue(disk); 537 rq_qos_exit(disk->queue); 538 out_put_slave_dir: 539 kobject_put(disk->slave_dir); 540 disk->slave_dir = NULL; 541 out_put_holder_dir: 542 kobject_put(disk->part0->bd_holder_dir); 543 out_del_block_link: 544 sysfs_remove_link(block_depr, dev_name(ddev)); 545 out_device_del: 546 device_del(ddev); 547 out_free_ext_minor: 548 if (disk->major == BLOCK_EXT_MAJOR) 549 blk_free_ext_minor(disk->first_minor); 550 out_exit_elevator: 551 if (disk->queue->elevator) 552 elevator_exit(disk->queue); 553 return ret; 554 } 555 EXPORT_SYMBOL(device_add_disk); 556 557 static void blk_report_disk_dead(struct gendisk *disk, bool surprise) 558 { 559 struct block_device *bdev; 560 unsigned long idx; 561 562 /* 563 * On surprise disk removal, bdev_mark_dead() may call into file 564 * systems below. Make it clear that we're expecting to not hold 565 * disk->open_mutex. 566 */ 567 lockdep_assert_not_held(&disk->open_mutex); 568 569 rcu_read_lock(); 570 xa_for_each(&disk->part_tbl, idx, bdev) { 571 if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) 572 continue; 573 rcu_read_unlock(); 574 575 bdev_mark_dead(bdev, surprise); 576 577 put_device(&bdev->bd_device); 578 rcu_read_lock(); 579 } 580 rcu_read_unlock(); 581 } 582 583 static void __blk_mark_disk_dead(struct gendisk *disk) 584 { 585 /* 586 * Fail any new I/O. 587 */ 588 if (test_and_set_bit(GD_DEAD, &disk->state)) 589 return; 590 591 if (test_bit(GD_OWNS_QUEUE, &disk->state)) 592 blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue); 593 594 /* 595 * Stop buffered writers from dirtying pages that can't be written out. 596 */ 597 set_capacity(disk, 0); 598 599 /* 600 * Prevent new I/O from crossing bio_queue_enter(). 601 */ 602 blk_queue_start_drain(disk->queue); 603 } 604 605 /** 606 * blk_mark_disk_dead - mark a disk as dead 607 * @disk: disk to mark as dead 608 * 609 * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O 610 * to this disk. 611 */ 612 void blk_mark_disk_dead(struct gendisk *disk) 613 { 614 __blk_mark_disk_dead(disk); 615 blk_report_disk_dead(disk, true); 616 } 617 EXPORT_SYMBOL_GPL(blk_mark_disk_dead); 618 619 /** 620 * del_gendisk - remove the gendisk 621 * @disk: the struct gendisk to remove 622 * 623 * Removes the gendisk and all its associated resources. This deletes the 624 * partitions associated with the gendisk, and unregisters the associated 625 * request_queue. 626 * 627 * This is the counter to the respective __device_add_disk() call. 628 * 629 * The final removal of the struct gendisk happens when its refcount reaches 0 630 * with put_disk(), which should be called after del_gendisk(), if 631 * __device_add_disk() was used. 632 * 633 * Drivers exist which depend on the release of the gendisk to be synchronous, 634 * it should not be deferred. 635 * 636 * Context: can sleep 637 */ 638 void del_gendisk(struct gendisk *disk) 639 { 640 struct request_queue *q = disk->queue; 641 struct block_device *part; 642 unsigned long idx; 643 644 might_sleep(); 645 646 if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN))) 647 return; 648 649 disk_del_events(disk); 650 651 /* 652 * Prevent new openers by unlinked the bdev inode. 653 */ 654 mutex_lock(&disk->open_mutex); 655 xa_for_each(&disk->part_tbl, idx, part) 656 remove_inode_hash(part->bd_inode); 657 mutex_unlock(&disk->open_mutex); 658 659 /* 660 * Tell the file system to write back all dirty data and shut down if 661 * it hasn't been notified earlier. 662 */ 663 if (!test_bit(GD_DEAD, &disk->state)) 664 blk_report_disk_dead(disk, false); 665 __blk_mark_disk_dead(disk); 666 667 /* 668 * Drop all partitions now that the disk is marked dead. 669 */ 670 mutex_lock(&disk->open_mutex); 671 xa_for_each_start(&disk->part_tbl, idx, part, 1) 672 drop_partition(part); 673 mutex_unlock(&disk->open_mutex); 674 675 if (!(disk->flags & GENHD_FL_HIDDEN)) { 676 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); 677 678 /* 679 * Unregister bdi before releasing device numbers (as they can 680 * get reused and we'd get clashes in sysfs). 681 */ 682 bdi_unregister(disk->bdi); 683 } 684 685 blk_unregister_queue(disk); 686 687 kobject_put(disk->part0->bd_holder_dir); 688 kobject_put(disk->slave_dir); 689 disk->slave_dir = NULL; 690 691 part_stat_set_all(disk->part0, 0); 692 disk->part0->bd_stamp = 0; 693 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); 694 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); 695 device_del(disk_to_dev(disk)); 696 697 blk_mq_freeze_queue_wait(q); 698 699 blk_throtl_cancel_bios(disk); 700 701 blk_sync_queue(q); 702 blk_flush_integrity(); 703 704 if (queue_is_mq(q)) 705 blk_mq_cancel_work_sync(q); 706 707 blk_mq_quiesce_queue(q); 708 if (q->elevator) { 709 mutex_lock(&q->sysfs_lock); 710 elevator_exit(q); 711 mutex_unlock(&q->sysfs_lock); 712 } 713 rq_qos_exit(q); 714 blk_mq_unquiesce_queue(q); 715 716 /* 717 * If the disk does not own the queue, allow using passthrough requests 718 * again. Else leave the queue frozen to fail all I/O. 719 */ 720 if (!test_bit(GD_OWNS_QUEUE, &disk->state)) { 721 blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); 722 __blk_mq_unfreeze_queue(q, true); 723 } else { 724 if (queue_is_mq(q)) 725 blk_mq_exit_queue(q); 726 } 727 } 728 EXPORT_SYMBOL(del_gendisk); 729 730 /** 731 * invalidate_disk - invalidate the disk 732 * @disk: the struct gendisk to invalidate 733 * 734 * A helper to invalidates the disk. It will clean the disk's associated 735 * buffer/page caches and reset its internal states so that the disk 736 * can be reused by the drivers. 737 * 738 * Context: can sleep 739 */ 740 void invalidate_disk(struct gendisk *disk) 741 { 742 struct block_device *bdev = disk->part0; 743 744 invalidate_bdev(bdev); 745 bdev->bd_inode->i_mapping->wb_err = 0; 746 set_capacity(disk, 0); 747 } 748 EXPORT_SYMBOL(invalidate_disk); 749 750 /* sysfs access to bad-blocks list. */ 751 static ssize_t disk_badblocks_show(struct device *dev, 752 struct device_attribute *attr, 753 char *page) 754 { 755 struct gendisk *disk = dev_to_disk(dev); 756 757 if (!disk->bb) 758 return sprintf(page, "\n"); 759 760 return badblocks_show(disk->bb, page, 0); 761 } 762 763 static ssize_t disk_badblocks_store(struct device *dev, 764 struct device_attribute *attr, 765 const char *page, size_t len) 766 { 767 struct gendisk *disk = dev_to_disk(dev); 768 769 if (!disk->bb) 770 return -ENXIO; 771 772 return badblocks_store(disk->bb, page, len, 0); 773 } 774 775 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD 776 void blk_request_module(dev_t devt) 777 { 778 unsigned int major = MAJOR(devt); 779 struct blk_major_name **n; 780 781 mutex_lock(&major_names_lock); 782 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) { 783 if ((*n)->major == major && (*n)->probe) { 784 (*n)->probe(devt); 785 mutex_unlock(&major_names_lock); 786 return; 787 } 788 } 789 mutex_unlock(&major_names_lock); 790 791 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) 792 /* Make old-style 2.4 aliases work */ 793 request_module("block-major-%d", MAJOR(devt)); 794 } 795 #endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */ 796 797 #ifdef CONFIG_PROC_FS 798 /* iterator */ 799 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) 800 { 801 loff_t skip = *pos; 802 struct class_dev_iter *iter; 803 struct device *dev; 804 805 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 806 if (!iter) 807 return ERR_PTR(-ENOMEM); 808 809 seqf->private = iter; 810 class_dev_iter_init(iter, &block_class, NULL, &disk_type); 811 do { 812 dev = class_dev_iter_next(iter); 813 if (!dev) 814 return NULL; 815 } while (skip--); 816 817 return dev_to_disk(dev); 818 } 819 820 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) 821 { 822 struct device *dev; 823 824 (*pos)++; 825 dev = class_dev_iter_next(seqf->private); 826 if (dev) 827 return dev_to_disk(dev); 828 829 return NULL; 830 } 831 832 static void disk_seqf_stop(struct seq_file *seqf, void *v) 833 { 834 struct class_dev_iter *iter = seqf->private; 835 836 /* stop is called even after start failed :-( */ 837 if (iter) { 838 class_dev_iter_exit(iter); 839 kfree(iter); 840 seqf->private = NULL; 841 } 842 } 843 844 static void *show_partition_start(struct seq_file *seqf, loff_t *pos) 845 { 846 void *p; 847 848 p = disk_seqf_start(seqf, pos); 849 if (!IS_ERR_OR_NULL(p) && !*pos) 850 seq_puts(seqf, "major minor #blocks name\n\n"); 851 return p; 852 } 853 854 static int show_partition(struct seq_file *seqf, void *v) 855 { 856 struct gendisk *sgp = v; 857 struct block_device *part; 858 unsigned long idx; 859 860 if (!get_capacity(sgp) || (sgp->flags & GENHD_FL_HIDDEN)) 861 return 0; 862 863 rcu_read_lock(); 864 xa_for_each(&sgp->part_tbl, idx, part) { 865 if (!bdev_nr_sectors(part)) 866 continue; 867 seq_printf(seqf, "%4d %7d %10llu %pg\n", 868 MAJOR(part->bd_dev), MINOR(part->bd_dev), 869 bdev_nr_sectors(part) >> 1, part); 870 } 871 rcu_read_unlock(); 872 return 0; 873 } 874 875 static const struct seq_operations partitions_op = { 876 .start = show_partition_start, 877 .next = disk_seqf_next, 878 .stop = disk_seqf_stop, 879 .show = show_partition 880 }; 881 #endif 882 883 static int __init genhd_device_init(void) 884 { 885 int error; 886 887 error = class_register(&block_class); 888 if (unlikely(error)) 889 return error; 890 blk_dev_init(); 891 892 register_blkdev(BLOCK_EXT_MAJOR, "blkext"); 893 894 /* create top-level block dir */ 895 block_depr = kobject_create_and_add("block", NULL); 896 return 0; 897 } 898 899 subsys_initcall(genhd_device_init); 900 901 static ssize_t disk_range_show(struct device *dev, 902 struct device_attribute *attr, char *buf) 903 { 904 struct gendisk *disk = dev_to_disk(dev); 905 906 return sprintf(buf, "%d\n", disk->minors); 907 } 908 909 static ssize_t disk_ext_range_show(struct device *dev, 910 struct device_attribute *attr, char *buf) 911 { 912 struct gendisk *disk = dev_to_disk(dev); 913 914 return sprintf(buf, "%d\n", 915 (disk->flags & GENHD_FL_NO_PART) ? 1 : DISK_MAX_PARTS); 916 } 917 918 static ssize_t disk_removable_show(struct device *dev, 919 struct device_attribute *attr, char *buf) 920 { 921 struct gendisk *disk = dev_to_disk(dev); 922 923 return sprintf(buf, "%d\n", 924 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); 925 } 926 927 static ssize_t disk_hidden_show(struct device *dev, 928 struct device_attribute *attr, char *buf) 929 { 930 struct gendisk *disk = dev_to_disk(dev); 931 932 return sprintf(buf, "%d\n", 933 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0)); 934 } 935 936 static ssize_t disk_ro_show(struct device *dev, 937 struct device_attribute *attr, char *buf) 938 { 939 struct gendisk *disk = dev_to_disk(dev); 940 941 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0); 942 } 943 944 ssize_t part_size_show(struct device *dev, 945 struct device_attribute *attr, char *buf) 946 { 947 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev))); 948 } 949 950 ssize_t part_stat_show(struct device *dev, 951 struct device_attribute *attr, char *buf) 952 { 953 struct block_device *bdev = dev_to_bdev(dev); 954 struct request_queue *q = bdev_get_queue(bdev); 955 struct disk_stats stat; 956 unsigned int inflight; 957 958 if (queue_is_mq(q)) 959 inflight = blk_mq_in_flight(q, bdev); 960 else 961 inflight = part_in_flight(bdev); 962 963 if (inflight) { 964 part_stat_lock(); 965 update_io_ticks(bdev, jiffies, true); 966 part_stat_unlock(); 967 } 968 part_stat_read_all(bdev, &stat); 969 return sprintf(buf, 970 "%8lu %8lu %8llu %8u " 971 "%8lu %8lu %8llu %8u " 972 "%8u %8u %8u " 973 "%8lu %8lu %8llu %8u " 974 "%8lu %8u" 975 "\n", 976 stat.ios[STAT_READ], 977 stat.merges[STAT_READ], 978 (unsigned long long)stat.sectors[STAT_READ], 979 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC), 980 stat.ios[STAT_WRITE], 981 stat.merges[STAT_WRITE], 982 (unsigned long long)stat.sectors[STAT_WRITE], 983 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC), 984 inflight, 985 jiffies_to_msecs(stat.io_ticks), 986 (unsigned int)div_u64(stat.nsecs[STAT_READ] + 987 stat.nsecs[STAT_WRITE] + 988 stat.nsecs[STAT_DISCARD] + 989 stat.nsecs[STAT_FLUSH], 990 NSEC_PER_MSEC), 991 stat.ios[STAT_DISCARD], 992 stat.merges[STAT_DISCARD], 993 (unsigned long long)stat.sectors[STAT_DISCARD], 994 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC), 995 stat.ios[STAT_FLUSH], 996 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC)); 997 } 998 999 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, 1000 char *buf) 1001 { 1002 struct block_device *bdev = dev_to_bdev(dev); 1003 struct request_queue *q = bdev_get_queue(bdev); 1004 unsigned int inflight[2]; 1005 1006 if (queue_is_mq(q)) 1007 blk_mq_in_flight_rw(q, bdev, inflight); 1008 else 1009 part_in_flight_rw(bdev, inflight); 1010 1011 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]); 1012 } 1013 1014 static ssize_t disk_capability_show(struct device *dev, 1015 struct device_attribute *attr, char *buf) 1016 { 1017 dev_warn_once(dev, "the capability attribute has been deprecated.\n"); 1018 return sprintf(buf, "0\n"); 1019 } 1020 1021 static ssize_t disk_alignment_offset_show(struct device *dev, 1022 struct device_attribute *attr, 1023 char *buf) 1024 { 1025 struct gendisk *disk = dev_to_disk(dev); 1026 1027 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0)); 1028 } 1029 1030 static ssize_t disk_discard_alignment_show(struct device *dev, 1031 struct device_attribute *attr, 1032 char *buf) 1033 { 1034 struct gendisk *disk = dev_to_disk(dev); 1035 1036 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0)); 1037 } 1038 1039 static ssize_t diskseq_show(struct device *dev, 1040 struct device_attribute *attr, char *buf) 1041 { 1042 struct gendisk *disk = dev_to_disk(dev); 1043 1044 return sprintf(buf, "%llu\n", disk->diskseq); 1045 } 1046 1047 static DEVICE_ATTR(range, 0444, disk_range_show, NULL); 1048 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL); 1049 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL); 1050 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL); 1051 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL); 1052 static DEVICE_ATTR(size, 0444, part_size_show, NULL); 1053 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL); 1054 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL); 1055 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL); 1056 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL); 1057 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL); 1058 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store); 1059 static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL); 1060 1061 #ifdef CONFIG_FAIL_MAKE_REQUEST 1062 ssize_t part_fail_show(struct device *dev, 1063 struct device_attribute *attr, char *buf) 1064 { 1065 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail); 1066 } 1067 1068 ssize_t part_fail_store(struct device *dev, 1069 struct device_attribute *attr, 1070 const char *buf, size_t count) 1071 { 1072 int i; 1073 1074 if (count > 0 && sscanf(buf, "%d", &i) > 0) 1075 dev_to_bdev(dev)->bd_make_it_fail = i; 1076 1077 return count; 1078 } 1079 1080 static struct device_attribute dev_attr_fail = 1081 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store); 1082 #endif /* CONFIG_FAIL_MAKE_REQUEST */ 1083 1084 #ifdef CONFIG_FAIL_IO_TIMEOUT 1085 static struct device_attribute dev_attr_fail_timeout = 1086 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store); 1087 #endif 1088 1089 static struct attribute *disk_attrs[] = { 1090 &dev_attr_range.attr, 1091 &dev_attr_ext_range.attr, 1092 &dev_attr_removable.attr, 1093 &dev_attr_hidden.attr, 1094 &dev_attr_ro.attr, 1095 &dev_attr_size.attr, 1096 &dev_attr_alignment_offset.attr, 1097 &dev_attr_discard_alignment.attr, 1098 &dev_attr_capability.attr, 1099 &dev_attr_stat.attr, 1100 &dev_attr_inflight.attr, 1101 &dev_attr_badblocks.attr, 1102 &dev_attr_events.attr, 1103 &dev_attr_events_async.attr, 1104 &dev_attr_events_poll_msecs.attr, 1105 &dev_attr_diskseq.attr, 1106 #ifdef CONFIG_FAIL_MAKE_REQUEST 1107 &dev_attr_fail.attr, 1108 #endif 1109 #ifdef CONFIG_FAIL_IO_TIMEOUT 1110 &dev_attr_fail_timeout.attr, 1111 #endif 1112 NULL 1113 }; 1114 1115 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n) 1116 { 1117 struct device *dev = container_of(kobj, typeof(*dev), kobj); 1118 struct gendisk *disk = dev_to_disk(dev); 1119 1120 if (a == &dev_attr_badblocks.attr && !disk->bb) 1121 return 0; 1122 return a->mode; 1123 } 1124 1125 static struct attribute_group disk_attr_group = { 1126 .attrs = disk_attrs, 1127 .is_visible = disk_visible, 1128 }; 1129 1130 static const struct attribute_group *disk_attr_groups[] = { 1131 &disk_attr_group, 1132 #ifdef CONFIG_BLK_DEV_IO_TRACE 1133 &blk_trace_attr_group, 1134 #endif 1135 #ifdef CONFIG_BLK_DEV_INTEGRITY 1136 &blk_integrity_attr_group, 1137 #endif 1138 NULL 1139 }; 1140 1141 /** 1142 * disk_release - releases all allocated resources of the gendisk 1143 * @dev: the device representing this disk 1144 * 1145 * This function releases all allocated resources of the gendisk. 1146 * 1147 * Drivers which used __device_add_disk() have a gendisk with a request_queue 1148 * assigned. Since the request_queue sits on top of the gendisk for these 1149 * drivers we also call blk_put_queue() for them, and we expect the 1150 * request_queue refcount to reach 0 at this point, and so the request_queue 1151 * will also be freed prior to the disk. 1152 * 1153 * Context: can sleep 1154 */ 1155 static void disk_release(struct device *dev) 1156 { 1157 struct gendisk *disk = dev_to_disk(dev); 1158 1159 might_sleep(); 1160 WARN_ON_ONCE(disk_live(disk)); 1161 1162 blk_trace_remove(disk->queue); 1163 1164 /* 1165 * To undo the all initialization from blk_mq_init_allocated_queue in 1166 * case of a probe failure where add_disk is never called we have to 1167 * call blk_mq_exit_queue here. We can't do this for the more common 1168 * teardown case (yet) as the tagset can be gone by the time the disk 1169 * is released once it was added. 1170 */ 1171 if (queue_is_mq(disk->queue) && 1172 test_bit(GD_OWNS_QUEUE, &disk->state) && 1173 !test_bit(GD_ADDED, &disk->state)) 1174 blk_mq_exit_queue(disk->queue); 1175 1176 blkcg_exit_disk(disk); 1177 1178 bioset_exit(&disk->bio_split); 1179 1180 disk_release_events(disk); 1181 kfree(disk->random); 1182 disk_free_zone_bitmaps(disk); 1183 xa_destroy(&disk->part_tbl); 1184 1185 disk->queue->disk = NULL; 1186 blk_put_queue(disk->queue); 1187 1188 if (test_bit(GD_ADDED, &disk->state) && disk->fops->free_disk) 1189 disk->fops->free_disk(disk); 1190 1191 iput(disk->part0->bd_inode); /* frees the disk */ 1192 } 1193 1194 static int block_uevent(const struct device *dev, struct kobj_uevent_env *env) 1195 { 1196 const struct gendisk *disk = dev_to_disk(dev); 1197 1198 return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq); 1199 } 1200 1201 struct class block_class = { 1202 .name = "block", 1203 .dev_uevent = block_uevent, 1204 }; 1205 1206 static char *block_devnode(const struct device *dev, umode_t *mode, 1207 kuid_t *uid, kgid_t *gid) 1208 { 1209 struct gendisk *disk = dev_to_disk(dev); 1210 1211 if (disk->fops->devnode) 1212 return disk->fops->devnode(disk, mode); 1213 return NULL; 1214 } 1215 1216 const struct device_type disk_type = { 1217 .name = "disk", 1218 .groups = disk_attr_groups, 1219 .release = disk_release, 1220 .devnode = block_devnode, 1221 }; 1222 1223 #ifdef CONFIG_PROC_FS 1224 /* 1225 * aggregate disk stat collector. Uses the same stats that the sysfs 1226 * entries do, above, but makes them available through one seq_file. 1227 * 1228 * The output looks suspiciously like /proc/partitions with a bunch of 1229 * extra fields. 1230 */ 1231 static int diskstats_show(struct seq_file *seqf, void *v) 1232 { 1233 struct gendisk *gp = v; 1234 struct block_device *hd; 1235 unsigned int inflight; 1236 struct disk_stats stat; 1237 unsigned long idx; 1238 1239 /* 1240 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) 1241 seq_puts(seqf, "major minor name" 1242 " rio rmerge rsect ruse wio wmerge " 1243 "wsect wuse running use aveq" 1244 "\n\n"); 1245 */ 1246 1247 rcu_read_lock(); 1248 xa_for_each(&gp->part_tbl, idx, hd) { 1249 if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) 1250 continue; 1251 if (queue_is_mq(gp->queue)) 1252 inflight = blk_mq_in_flight(gp->queue, hd); 1253 else 1254 inflight = part_in_flight(hd); 1255 1256 if (inflight) { 1257 part_stat_lock(); 1258 update_io_ticks(hd, jiffies, true); 1259 part_stat_unlock(); 1260 } 1261 part_stat_read_all(hd, &stat); 1262 seq_printf(seqf, "%4d %7d %pg " 1263 "%lu %lu %lu %u " 1264 "%lu %lu %lu %u " 1265 "%u %u %u " 1266 "%lu %lu %lu %u " 1267 "%lu %u" 1268 "\n", 1269 MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd, 1270 stat.ios[STAT_READ], 1271 stat.merges[STAT_READ], 1272 stat.sectors[STAT_READ], 1273 (unsigned int)div_u64(stat.nsecs[STAT_READ], 1274 NSEC_PER_MSEC), 1275 stat.ios[STAT_WRITE], 1276 stat.merges[STAT_WRITE], 1277 stat.sectors[STAT_WRITE], 1278 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], 1279 NSEC_PER_MSEC), 1280 inflight, 1281 jiffies_to_msecs(stat.io_ticks), 1282 (unsigned int)div_u64(stat.nsecs[STAT_READ] + 1283 stat.nsecs[STAT_WRITE] + 1284 stat.nsecs[STAT_DISCARD] + 1285 stat.nsecs[STAT_FLUSH], 1286 NSEC_PER_MSEC), 1287 stat.ios[STAT_DISCARD], 1288 stat.merges[STAT_DISCARD], 1289 stat.sectors[STAT_DISCARD], 1290 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], 1291 NSEC_PER_MSEC), 1292 stat.ios[STAT_FLUSH], 1293 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], 1294 NSEC_PER_MSEC) 1295 ); 1296 } 1297 rcu_read_unlock(); 1298 1299 return 0; 1300 } 1301 1302 static const struct seq_operations diskstats_op = { 1303 .start = disk_seqf_start, 1304 .next = disk_seqf_next, 1305 .stop = disk_seqf_stop, 1306 .show = diskstats_show 1307 }; 1308 1309 static int __init proc_genhd_init(void) 1310 { 1311 proc_create_seq("diskstats", 0, NULL, &diskstats_op); 1312 proc_create_seq("partitions", 0, NULL, &partitions_op); 1313 return 0; 1314 } 1315 module_init(proc_genhd_init); 1316 #endif /* CONFIG_PROC_FS */ 1317 1318 dev_t part_devt(struct gendisk *disk, u8 partno) 1319 { 1320 struct block_device *part; 1321 dev_t devt = 0; 1322 1323 rcu_read_lock(); 1324 part = xa_load(&disk->part_tbl, partno); 1325 if (part) 1326 devt = part->bd_dev; 1327 rcu_read_unlock(); 1328 1329 return devt; 1330 } 1331 1332 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, 1333 struct lock_class_key *lkclass) 1334 { 1335 struct gendisk *disk; 1336 1337 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); 1338 if (!disk) 1339 return NULL; 1340 1341 if (bioset_init(&disk->bio_split, BIO_POOL_SIZE, 0, 0)) 1342 goto out_free_disk; 1343 1344 disk->bdi = bdi_alloc(node_id); 1345 if (!disk->bdi) 1346 goto out_free_bioset; 1347 1348 /* bdev_alloc() might need the queue, set before the first call */ 1349 disk->queue = q; 1350 1351 disk->part0 = bdev_alloc(disk, 0); 1352 if (!disk->part0) 1353 goto out_free_bdi; 1354 1355 disk->node_id = node_id; 1356 mutex_init(&disk->open_mutex); 1357 xa_init(&disk->part_tbl); 1358 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL)) 1359 goto out_destroy_part_tbl; 1360 1361 if (blkcg_init_disk(disk)) 1362 goto out_erase_part0; 1363 1364 rand_initialize_disk(disk); 1365 disk_to_dev(disk)->class = &block_class; 1366 disk_to_dev(disk)->type = &disk_type; 1367 device_initialize(disk_to_dev(disk)); 1368 inc_diskseq(disk); 1369 q->disk = disk; 1370 lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0); 1371 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED 1372 INIT_LIST_HEAD(&disk->slave_bdevs); 1373 #endif 1374 return disk; 1375 1376 out_erase_part0: 1377 xa_erase(&disk->part_tbl, 0); 1378 out_destroy_part_tbl: 1379 xa_destroy(&disk->part_tbl); 1380 disk->part0->bd_disk = NULL; 1381 iput(disk->part0->bd_inode); 1382 out_free_bdi: 1383 bdi_put(disk->bdi); 1384 out_free_bioset: 1385 bioset_exit(&disk->bio_split); 1386 out_free_disk: 1387 kfree(disk); 1388 return NULL; 1389 } 1390 1391 struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass) 1392 { 1393 struct request_queue *q; 1394 struct gendisk *disk; 1395 1396 q = blk_alloc_queue(node); 1397 if (!q) 1398 return NULL; 1399 1400 disk = __alloc_disk_node(q, node, lkclass); 1401 if (!disk) { 1402 blk_put_queue(q); 1403 return NULL; 1404 } 1405 set_bit(GD_OWNS_QUEUE, &disk->state); 1406 return disk; 1407 } 1408 EXPORT_SYMBOL(__blk_alloc_disk); 1409 1410 /** 1411 * put_disk - decrements the gendisk refcount 1412 * @disk: the struct gendisk to decrement the refcount for 1413 * 1414 * This decrements the refcount for the struct gendisk. When this reaches 0 1415 * we'll have disk_release() called. 1416 * 1417 * Note: for blk-mq disk put_disk must be called before freeing the tag_set 1418 * when handling probe errors (that is before add_disk() is called). 1419 * 1420 * Context: Any context, but the last reference must not be dropped from 1421 * atomic context. 1422 */ 1423 void put_disk(struct gendisk *disk) 1424 { 1425 if (disk) 1426 put_device(disk_to_dev(disk)); 1427 } 1428 EXPORT_SYMBOL(put_disk); 1429 1430 static void set_disk_ro_uevent(struct gendisk *gd, int ro) 1431 { 1432 char event[] = "DISK_RO=1"; 1433 char *envp[] = { event, NULL }; 1434 1435 if (!ro) 1436 event[8] = '0'; 1437 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); 1438 } 1439 1440 /** 1441 * set_disk_ro - set a gendisk read-only 1442 * @disk: gendisk to operate on 1443 * @read_only: %true to set the disk read-only, %false set the disk read/write 1444 * 1445 * This function is used to indicate whether a given disk device should have its 1446 * read-only flag set. set_disk_ro() is typically used by device drivers to 1447 * indicate whether the underlying physical device is write-protected. 1448 */ 1449 void set_disk_ro(struct gendisk *disk, bool read_only) 1450 { 1451 if (read_only) { 1452 if (test_and_set_bit(GD_READ_ONLY, &disk->state)) 1453 return; 1454 } else { 1455 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state)) 1456 return; 1457 } 1458 set_disk_ro_uevent(disk, read_only); 1459 } 1460 EXPORT_SYMBOL(set_disk_ro); 1461 1462 void inc_diskseq(struct gendisk *disk) 1463 { 1464 disk->diskseq = atomic64_inc_return(&diskseq); 1465 } 1466