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 36static 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 */ 53static atomic64_t diskseq; 54 55/* for extended dynamic devt allocation, currently only one major is used */ 56#define NR_EXT_DEVT (1 << MINORBITS) 57static DEFINE_IDA(ext_devt_ida); 58 59void set_capacity(struct gendisk *disk, sector_t sectors) 60{ 61 bdev_set_nr_sectors(disk->part0, sectors); 62} 63EXPORT_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 */ 69bool 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} 98EXPORT_SYMBOL_GPL(set_capacity_and_notify); 99 100static 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 121static 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 136static 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 158static 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]; 166static DEFINE_MUTEX(major_names_lock); 167static DEFINE_SPINLOCK(major_names_spinlock); 168 169/* index in the above - for now: assume no multimajor ranges */ 170static inline int major_to_index(unsigned major) 171{ 172 return major % BLKDEV_MAJOR_HASH_SIZE; 173} 174 175#ifdef CONFIG_PROC_FS 176void 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 */ 214int __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 } 277out: 278 mutex_unlock(&major_names_lock); 279 return ret; 280} 281EXPORT_SYMBOL(__register_blkdev); 282 283void 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 305EXPORT_SYMBOL(unregister_blkdev); 306 307int 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 317void blk_free_ext_minor(unsigned int minor) 318{ 319 ida_free(&ext_devt_ida, minor); 320} 321 322void 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} 341EXPORT_SYMBOL_GPL(disk_uevent); 342 343int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode) 344{ 345 struct file *file; 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 file = bdev_file_open_by_dev(disk_devt(disk), mode & ~BLK_OPEN_EXCL, 370 NULL, NULL); 371 if (IS_ERR(file)) 372 ret = PTR_ERR(file); 373 else 374 fput(file); 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 */ 396int __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 > MINORMASK || 436 disk->minors > MINORMASK + 1 || 437 disk->first_minor + disk->minors > MINORMASK + 1) 438 goto out_exit_elevator; 439 } else { 440 if (WARN_ON(disk->minors)) 441 goto out_exit_elevator; 442 443 ret = blk_alloc_ext_minor(); 444 if (ret < 0) 445 goto out_exit_elevator; 446 disk->major = BLOCK_EXT_MAJOR; 447 disk->first_minor = ret; 448 } 449 450 /* delay uevents, until we scanned partition table */ 451 dev_set_uevent_suppress(ddev, 1); 452 453 ddev->parent = parent; 454 ddev->groups = groups; 455 dev_set_name(ddev, "%s", disk->disk_name); 456 if (!(disk->flags & GENHD_FL_HIDDEN)) 457 ddev->devt = MKDEV(disk->major, disk->first_minor); 458 ret = device_add(ddev); 459 if (ret) 460 goto out_free_ext_minor; 461 462 ret = disk_alloc_events(disk); 463 if (ret) 464 goto out_device_del; 465 466 ret = sysfs_create_link(block_depr, &ddev->kobj, 467 kobject_name(&ddev->kobj)); 468 if (ret) 469 goto out_device_del; 470 471 /* 472 * avoid probable deadlock caused by allocating memory with 473 * GFP_KERNEL in runtime_resume callback of its all ancestor 474 * devices 475 */ 476 pm_runtime_set_memalloc_noio(ddev, true); 477 478 disk->part0->bd_holder_dir = 479 kobject_create_and_add("holders", &ddev->kobj); 480 if (!disk->part0->bd_holder_dir) { 481 ret = -ENOMEM; 482 goto out_del_block_link; 483 } 484 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); 485 if (!disk->slave_dir) { 486 ret = -ENOMEM; 487 goto out_put_holder_dir; 488 } 489 490 ret = blk_register_queue(disk); 491 if (ret) 492 goto out_put_slave_dir; 493 494 if (!(disk->flags & GENHD_FL_HIDDEN)) { 495 ret = bdi_register(disk->bdi, "%u:%u", 496 disk->major, disk->first_minor); 497 if (ret) 498 goto out_unregister_queue; 499 bdi_set_owner(disk->bdi, ddev); 500 ret = sysfs_create_link(&ddev->kobj, 501 &disk->bdi->dev->kobj, "bdi"); 502 if (ret) 503 goto out_unregister_bdi; 504 505 /* Make sure the first partition scan will be proceed */ 506 if (get_capacity(disk) && !(disk->flags & GENHD_FL_NO_PART) && 507 !test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) 508 set_bit(GD_NEED_PART_SCAN, &disk->state); 509 510 bdev_add(disk->part0, ddev->devt); 511 if (get_capacity(disk)) 512 disk_scan_partitions(disk, BLK_OPEN_READ); 513 514 /* 515 * Announce the disk and partitions after all partitions are 516 * created. (for hidden disks uevents remain suppressed forever) 517 */ 518 dev_set_uevent_suppress(ddev, 0); 519 disk_uevent(disk, KOBJ_ADD); 520 } else { 521 /* 522 * Even if the block_device for a hidden gendisk is not 523 * registered, it needs to have a valid bd_dev so that the 524 * freeing of the dynamic major works. 525 */ 526 disk->part0->bd_dev = MKDEV(disk->major, disk->first_minor); 527 } 528 529 disk_update_readahead(disk); 530 disk_add_events(disk); 531 set_bit(GD_ADDED, &disk->state); 532 return 0; 533 534out_unregister_bdi: 535 if (!(disk->flags & GENHD_FL_HIDDEN)) 536 bdi_unregister(disk->bdi); 537out_unregister_queue: 538 blk_unregister_queue(disk); 539 rq_qos_exit(disk->queue); 540out_put_slave_dir: 541 kobject_put(disk->slave_dir); 542 disk->slave_dir = NULL; 543out_put_holder_dir: 544 kobject_put(disk->part0->bd_holder_dir); 545out_del_block_link: 546 sysfs_remove_link(block_depr, dev_name(ddev)); 547 pm_runtime_set_memalloc_noio(ddev, false); 548out_device_del: 549 device_del(ddev); 550out_free_ext_minor: 551 if (disk->major == BLOCK_EXT_MAJOR) 552 blk_free_ext_minor(disk->first_minor); 553out_exit_elevator: 554 if (disk->queue->elevator) 555 elevator_exit(disk->queue); 556 return ret; 557} 558EXPORT_SYMBOL(device_add_disk); 559 560static void blk_report_disk_dead(struct gendisk *disk, bool surprise) 561{ 562 struct block_device *bdev; 563 unsigned long idx; 564 565 /* 566 * On surprise disk removal, bdev_mark_dead() may call into file 567 * systems below. Make it clear that we're expecting to not hold 568 * disk->open_mutex. 569 */ 570 lockdep_assert_not_held(&disk->open_mutex); 571 572 rcu_read_lock(); 573 xa_for_each(&disk->part_tbl, idx, bdev) { 574 if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) 575 continue; 576 rcu_read_unlock(); 577 578 bdev_mark_dead(bdev, surprise); 579 580 put_device(&bdev->bd_device); 581 rcu_read_lock(); 582 } 583 rcu_read_unlock(); 584} 585 586static void __blk_mark_disk_dead(struct gendisk *disk) 587{ 588 /* 589 * Fail any new I/O. 590 */ 591 if (test_and_set_bit(GD_DEAD, &disk->state)) 592 return; 593 594 if (test_bit(GD_OWNS_QUEUE, &disk->state)) 595 blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue); 596 597 /* 598 * Stop buffered writers from dirtying pages that can't be written out. 599 */ 600 set_capacity(disk, 0); 601 602 /* 603 * Prevent new I/O from crossing bio_queue_enter(). 604 */ 605 blk_queue_start_drain(disk->queue); 606} 607 608/** 609 * blk_mark_disk_dead - mark a disk as dead 610 * @disk: disk to mark as dead 611 * 612 * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O 613 * to this disk. 614 */ 615void blk_mark_disk_dead(struct gendisk *disk) 616{ 617 __blk_mark_disk_dead(disk); 618 blk_report_disk_dead(disk, true); 619} 620EXPORT_SYMBOL_GPL(blk_mark_disk_dead); 621 622/** 623 * del_gendisk - remove the gendisk 624 * @disk: the struct gendisk to remove 625 * 626 * Removes the gendisk and all its associated resources. This deletes the 627 * partitions associated with the gendisk, and unregisters the associated 628 * request_queue. 629 * 630 * This is the counter to the respective __device_add_disk() call. 631 * 632 * The final removal of the struct gendisk happens when its refcount reaches 0 633 * with put_disk(), which should be called after del_gendisk(), if 634 * __device_add_disk() was used. 635 * 636 * Drivers exist which depend on the release of the gendisk to be synchronous, 637 * it should not be deferred. 638 * 639 * Context: can sleep 640 */ 641void del_gendisk(struct gendisk *disk) 642{ 643 struct request_queue *q = disk->queue; 644 struct block_device *part; 645 unsigned long idx; 646 647 might_sleep(); 648 649 if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN))) 650 return; 651 652 disk_del_events(disk); 653 654 /* 655 * Prevent new openers by unlinked the bdev inode. 656 */ 657 mutex_lock(&disk->open_mutex); 658 xa_for_each(&disk->part_tbl, idx, part) 659 remove_inode_hash(part->bd_inode); 660 mutex_unlock(&disk->open_mutex); 661 662 /* 663 * Tell the file system to write back all dirty data and shut down if 664 * it hasn't been notified earlier. 665 */ 666 if (!test_bit(GD_DEAD, &disk->state)) 667 blk_report_disk_dead(disk, false); 668 __blk_mark_disk_dead(disk); 669 670 /* 671 * Drop all partitions now that the disk is marked dead. 672 */ 673 mutex_lock(&disk->open_mutex); 674 xa_for_each_start(&disk->part_tbl, idx, part, 1) 675 drop_partition(part); 676 mutex_unlock(&disk->open_mutex); 677 678 if (!(disk->flags & GENHD_FL_HIDDEN)) { 679 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); 680 681 /* 682 * Unregister bdi before releasing device numbers (as they can 683 * get reused and we'd get clashes in sysfs). 684 */ 685 bdi_unregister(disk->bdi); 686 } 687 688 blk_unregister_queue(disk); 689 690 kobject_put(disk->part0->bd_holder_dir); 691 kobject_put(disk->slave_dir); 692 disk->slave_dir = NULL; 693 694 part_stat_set_all(disk->part0, 0); 695 disk->part0->bd_stamp = 0; 696 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); 697 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); 698 device_del(disk_to_dev(disk)); 699 700 blk_mq_freeze_queue_wait(q); 701 702 blk_throtl_cancel_bios(disk); 703 704 blk_sync_queue(q); 705 blk_flush_integrity(); 706 707 if (queue_is_mq(q)) 708 blk_mq_cancel_work_sync(q); 709 710 blk_mq_quiesce_queue(q); 711 if (q->elevator) { 712 mutex_lock(&q->sysfs_lock); 713 elevator_exit(q); 714 mutex_unlock(&q->sysfs_lock); 715 } 716 rq_qos_exit(q); 717 blk_mq_unquiesce_queue(q); 718 719 /* 720 * If the disk does not own the queue, allow using passthrough requests 721 * again. Else leave the queue frozen to fail all I/O. 722 */ 723 if (!test_bit(GD_OWNS_QUEUE, &disk->state)) { 724 blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); 725 __blk_mq_unfreeze_queue(q, true); 726 } else { 727 if (queue_is_mq(q)) 728 blk_mq_exit_queue(q); 729 } 730} 731EXPORT_SYMBOL(del_gendisk); 732 733/** 734 * invalidate_disk - invalidate the disk 735 * @disk: the struct gendisk to invalidate 736 * 737 * A helper to invalidates the disk. It will clean the disk's associated 738 * buffer/page caches and reset its internal states so that the disk 739 * can be reused by the drivers. 740 * 741 * Context: can sleep 742 */ 743void invalidate_disk(struct gendisk *disk) 744{ 745 struct block_device *bdev = disk->part0; 746 747 invalidate_bdev(bdev); 748 bdev->bd_inode->i_mapping->wb_err = 0; 749 set_capacity(disk, 0); 750} 751EXPORT_SYMBOL(invalidate_disk); 752 753/* sysfs access to bad-blocks list. */ 754static ssize_t disk_badblocks_show(struct device *dev, 755 struct device_attribute *attr, 756 char *page) 757{ 758 struct gendisk *disk = dev_to_disk(dev); 759 760 if (!disk->bb) 761 return sprintf(page, "\n"); 762 763 return badblocks_show(disk->bb, page, 0); 764} 765 766static ssize_t disk_badblocks_store(struct device *dev, 767 struct device_attribute *attr, 768 const char *page, size_t len) 769{ 770 struct gendisk *disk = dev_to_disk(dev); 771 772 if (!disk->bb) 773 return -ENXIO; 774 775 return badblocks_store(disk->bb, page, len, 0); 776} 777 778#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD 779void blk_request_module(dev_t devt) 780{ 781 unsigned int major = MAJOR(devt); 782 struct blk_major_name **n; 783 784 mutex_lock(&major_names_lock); 785 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) { 786 if ((*n)->major == major && (*n)->probe) { 787 (*n)->probe(devt); 788 mutex_unlock(&major_names_lock); 789 return; 790 } 791 } 792 mutex_unlock(&major_names_lock); 793 794 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) 795 /* Make old-style 2.4 aliases work */ 796 request_module("block-major-%d", MAJOR(devt)); 797} 798#endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */ 799 800#ifdef CONFIG_PROC_FS 801/* iterator */ 802static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) 803{ 804 loff_t skip = *pos; 805 struct class_dev_iter *iter; 806 struct device *dev; 807 808 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 809 if (!iter) 810 return ERR_PTR(-ENOMEM); 811 812 seqf->private = iter; 813 class_dev_iter_init(iter, &block_class, NULL, &disk_type); 814 do { 815 dev = class_dev_iter_next(iter); 816 if (!dev) 817 return NULL; 818 } while (skip--); 819 820 return dev_to_disk(dev); 821} 822 823static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) 824{ 825 struct device *dev; 826 827 (*pos)++; 828 dev = class_dev_iter_next(seqf->private); 829 if (dev) 830 return dev_to_disk(dev); 831 832 return NULL; 833} 834 835static void disk_seqf_stop(struct seq_file *seqf, void *v) 836{ 837 struct class_dev_iter *iter = seqf->private; 838 839 /* stop is called even after start failed :-( */ 840 if (iter) { 841 class_dev_iter_exit(iter); 842 kfree(iter); 843 seqf->private = NULL; 844 } 845} 846 847static void *show_partition_start(struct seq_file *seqf, loff_t *pos) 848{ 849 void *p; 850 851 p = disk_seqf_start(seqf, pos); 852 if (!IS_ERR_OR_NULL(p) && !*pos) 853 seq_puts(seqf, "major minor #blocks name\n\n"); 854 return p; 855} 856 857static int show_partition(struct seq_file *seqf, void *v) 858{ 859 struct gendisk *sgp = v; 860 struct block_device *part; 861 unsigned long idx; 862 863 if (!get_capacity(sgp) || (sgp->flags & GENHD_FL_HIDDEN)) 864 return 0; 865 866 rcu_read_lock(); 867 xa_for_each(&sgp->part_tbl, idx, part) { 868 if (!bdev_nr_sectors(part)) 869 continue; 870 seq_printf(seqf, "%4d %7d %10llu %pg\n", 871 MAJOR(part->bd_dev), MINOR(part->bd_dev), 872 bdev_nr_sectors(part) >> 1, part); 873 } 874 rcu_read_unlock(); 875 return 0; 876} 877 878static const struct seq_operations partitions_op = { 879 .start = show_partition_start, 880 .next = disk_seqf_next, 881 .stop = disk_seqf_stop, 882 .show = show_partition 883}; 884#endif 885 886static int __init genhd_device_init(void) 887{ 888 int error; 889 890 error = class_register(&block_class); 891 if (unlikely(error)) 892 return error; 893 blk_dev_init(); 894 895 register_blkdev(BLOCK_EXT_MAJOR, "blkext"); 896 897 /* create top-level block dir */ 898 block_depr = kobject_create_and_add("block", NULL); 899 return 0; 900} 901 902subsys_initcall(genhd_device_init); 903 904static ssize_t disk_range_show(struct device *dev, 905 struct device_attribute *attr, char *buf) 906{ 907 struct gendisk *disk = dev_to_disk(dev); 908 909 return sprintf(buf, "%d\n", disk->minors); 910} 911 912static ssize_t disk_ext_range_show(struct device *dev, 913 struct device_attribute *attr, char *buf) 914{ 915 struct gendisk *disk = dev_to_disk(dev); 916 917 return sprintf(buf, "%d\n", 918 (disk->flags & GENHD_FL_NO_PART) ? 1 : DISK_MAX_PARTS); 919} 920 921static ssize_t disk_removable_show(struct device *dev, 922 struct device_attribute *attr, char *buf) 923{ 924 struct gendisk *disk = dev_to_disk(dev); 925 926 return sprintf(buf, "%d\n", 927 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); 928} 929 930static ssize_t disk_hidden_show(struct device *dev, 931 struct device_attribute *attr, char *buf) 932{ 933 struct gendisk *disk = dev_to_disk(dev); 934 935 return sprintf(buf, "%d\n", 936 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0)); 937} 938 939static ssize_t disk_ro_show(struct device *dev, 940 struct device_attribute *attr, char *buf) 941{ 942 struct gendisk *disk = dev_to_disk(dev); 943 944 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0); 945} 946 947ssize_t part_size_show(struct device *dev, 948 struct device_attribute *attr, char *buf) 949{ 950 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev))); 951} 952 953ssize_t part_stat_show(struct device *dev, 954 struct device_attribute *attr, char *buf) 955{ 956 struct block_device *bdev = dev_to_bdev(dev); 957 struct request_queue *q = bdev_get_queue(bdev); 958 struct disk_stats stat; 959 unsigned int inflight; 960 961 if (queue_is_mq(q)) 962 inflight = blk_mq_in_flight(q, bdev); 963 else 964 inflight = part_in_flight(bdev); 965 966 if (inflight) { 967 part_stat_lock(); 968 update_io_ticks(bdev, jiffies, true); 969 part_stat_unlock(); 970 } 971 part_stat_read_all(bdev, &stat); 972 return sprintf(buf, 973 "%8lu %8lu %8llu %8u " 974 "%8lu %8lu %8llu %8u " 975 "%8u %8u %8u " 976 "%8lu %8lu %8llu %8u " 977 "%8lu %8u" 978 "\n", 979 stat.ios[STAT_READ], 980 stat.merges[STAT_READ], 981 (unsigned long long)stat.sectors[STAT_READ], 982 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC), 983 stat.ios[STAT_WRITE], 984 stat.merges[STAT_WRITE], 985 (unsigned long long)stat.sectors[STAT_WRITE], 986 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC), 987 inflight, 988 jiffies_to_msecs(stat.io_ticks), 989 (unsigned int)div_u64(stat.nsecs[STAT_READ] + 990 stat.nsecs[STAT_WRITE] + 991 stat.nsecs[STAT_DISCARD] + 992 stat.nsecs[STAT_FLUSH], 993 NSEC_PER_MSEC), 994 stat.ios[STAT_DISCARD], 995 stat.merges[STAT_DISCARD], 996 (unsigned long long)stat.sectors[STAT_DISCARD], 997 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC), 998 stat.ios[STAT_FLUSH], 999 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC)); 1000} 1001 1002ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, 1003 char *buf) 1004{ 1005 struct block_device *bdev = dev_to_bdev(dev); 1006 struct request_queue *q = bdev_get_queue(bdev); 1007 unsigned int inflight[2]; 1008 1009 if (queue_is_mq(q)) 1010 blk_mq_in_flight_rw(q, bdev, inflight); 1011 else 1012 part_in_flight_rw(bdev, inflight); 1013 1014 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]); 1015} 1016 1017static ssize_t disk_capability_show(struct device *dev, 1018 struct device_attribute *attr, char *buf) 1019{ 1020 dev_warn_once(dev, "the capability attribute has been deprecated.\n"); 1021 return sprintf(buf, "0\n"); 1022} 1023 1024static ssize_t disk_alignment_offset_show(struct device *dev, 1025 struct device_attribute *attr, 1026 char *buf) 1027{ 1028 struct gendisk *disk = dev_to_disk(dev); 1029 1030 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0)); 1031} 1032 1033static ssize_t disk_discard_alignment_show(struct device *dev, 1034 struct device_attribute *attr, 1035 char *buf) 1036{ 1037 struct gendisk *disk = dev_to_disk(dev); 1038 1039 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0)); 1040} 1041 1042static ssize_t diskseq_show(struct device *dev, 1043 struct device_attribute *attr, char *buf) 1044{ 1045 struct gendisk *disk = dev_to_disk(dev); 1046 1047 return sprintf(buf, "%llu\n", disk->diskseq); 1048} 1049 1050static DEVICE_ATTR(range, 0444, disk_range_show, NULL); 1051static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL); 1052static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL); 1053static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL); 1054static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL); 1055static DEVICE_ATTR(size, 0444, part_size_show, NULL); 1056static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL); 1057static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL); 1058static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL); 1059static DEVICE_ATTR(stat, 0444, part_stat_show, NULL); 1060static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL); 1061static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store); 1062static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL); 1063 1064#ifdef CONFIG_FAIL_MAKE_REQUEST 1065ssize_t part_fail_show(struct device *dev, 1066 struct device_attribute *attr, char *buf) 1067{ 1068 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail); 1069} 1070 1071ssize_t part_fail_store(struct device *dev, 1072 struct device_attribute *attr, 1073 const char *buf, size_t count) 1074{ 1075 int i; 1076 1077 if (count > 0 && sscanf(buf, "%d", &i) > 0) 1078 dev_to_bdev(dev)->bd_make_it_fail = i; 1079 1080 return count; 1081} 1082 1083static struct device_attribute dev_attr_fail = 1084 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store); 1085#endif /* CONFIG_FAIL_MAKE_REQUEST */ 1086 1087#ifdef CONFIG_FAIL_IO_TIMEOUT 1088static struct device_attribute dev_attr_fail_timeout = 1089 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store); 1090#endif 1091 1092static struct attribute *disk_attrs[] = { 1093 &dev_attr_range.attr, 1094 &dev_attr_ext_range.attr, 1095 &dev_attr_removable.attr, 1096 &dev_attr_hidden.attr, 1097 &dev_attr_ro.attr, 1098 &dev_attr_size.attr, 1099 &dev_attr_alignment_offset.attr, 1100 &dev_attr_discard_alignment.attr, 1101 &dev_attr_capability.attr, 1102 &dev_attr_stat.attr, 1103 &dev_attr_inflight.attr, 1104 &dev_attr_badblocks.attr, 1105 &dev_attr_events.attr, 1106 &dev_attr_events_async.attr, 1107 &dev_attr_events_poll_msecs.attr, 1108 &dev_attr_diskseq.attr, 1109#ifdef CONFIG_FAIL_MAKE_REQUEST 1110 &dev_attr_fail.attr, 1111#endif 1112#ifdef CONFIG_FAIL_IO_TIMEOUT 1113 &dev_attr_fail_timeout.attr, 1114#endif 1115 NULL 1116}; 1117 1118static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n) 1119{ 1120 struct device *dev = container_of(kobj, typeof(*dev), kobj); 1121 struct gendisk *disk = dev_to_disk(dev); 1122 1123 if (a == &dev_attr_badblocks.attr && !disk->bb) 1124 return 0; 1125 return a->mode; 1126} 1127 1128static struct attribute_group disk_attr_group = { 1129 .attrs = disk_attrs, 1130 .is_visible = disk_visible, 1131}; 1132 1133static const struct attribute_group *disk_attr_groups[] = { 1134 &disk_attr_group, 1135#ifdef CONFIG_BLK_DEV_IO_TRACE 1136 &blk_trace_attr_group, 1137#endif 1138#ifdef CONFIG_BLK_DEV_INTEGRITY 1139 &blk_integrity_attr_group, 1140#endif 1141 NULL 1142}; 1143 1144/** 1145 * disk_release - releases all allocated resources of the gendisk 1146 * @dev: the device representing this disk 1147 * 1148 * This function releases all allocated resources of the gendisk. 1149 * 1150 * Drivers which used __device_add_disk() have a gendisk with a request_queue 1151 * assigned. Since the request_queue sits on top of the gendisk for these 1152 * drivers we also call blk_put_queue() for them, and we expect the 1153 * request_queue refcount to reach 0 at this point, and so the request_queue 1154 * will also be freed prior to the disk. 1155 * 1156 * Context: can sleep 1157 */ 1158static void disk_release(struct device *dev) 1159{ 1160 struct gendisk *disk = dev_to_disk(dev); 1161 1162 might_sleep(); 1163 WARN_ON_ONCE(disk_live(disk)); 1164 1165 blk_trace_remove(disk->queue); 1166 1167 /* 1168 * To undo the all initialization from blk_mq_init_allocated_queue in 1169 * case of a probe failure where add_disk is never called we have to 1170 * call blk_mq_exit_queue here. We can't do this for the more common 1171 * teardown case (yet) as the tagset can be gone by the time the disk 1172 * is released once it was added. 1173 */ 1174 if (queue_is_mq(disk->queue) && 1175 test_bit(GD_OWNS_QUEUE, &disk->state) && 1176 !test_bit(GD_ADDED, &disk->state)) 1177 blk_mq_exit_queue(disk->queue); 1178 1179 blkcg_exit_disk(disk); 1180 1181 bioset_exit(&disk->bio_split); 1182 1183 disk_release_events(disk); 1184 kfree(disk->random); 1185 disk_free_zone_bitmaps(disk); 1186 xa_destroy(&disk->part_tbl); 1187 1188 disk->queue->disk = NULL; 1189 blk_put_queue(disk->queue); 1190 1191 if (test_bit(GD_ADDED, &disk->state) && disk->fops->free_disk) 1192 disk->fops->free_disk(disk); 1193 1194 iput(disk->part0->bd_inode); /* frees the disk */ 1195} 1196 1197static int block_uevent(const struct device *dev, struct kobj_uevent_env *env) 1198{ 1199 const struct gendisk *disk = dev_to_disk(dev); 1200 1201 return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq); 1202} 1203 1204const struct class block_class = { 1205 .name = "block", 1206 .dev_uevent = block_uevent, 1207}; 1208 1209static char *block_devnode(const struct device *dev, umode_t *mode, 1210 kuid_t *uid, kgid_t *gid) 1211{ 1212 struct gendisk *disk = dev_to_disk(dev); 1213 1214 if (disk->fops->devnode) 1215 return disk->fops->devnode(disk, mode); 1216 return NULL; 1217} 1218 1219const struct device_type disk_type = { 1220 .name = "disk", 1221 .groups = disk_attr_groups, 1222 .release = disk_release, 1223 .devnode = block_devnode, 1224}; 1225 1226#ifdef CONFIG_PROC_FS 1227/* 1228 * aggregate disk stat collector. Uses the same stats that the sysfs 1229 * entries do, above, but makes them available through one seq_file. 1230 * 1231 * The output looks suspiciously like /proc/partitions with a bunch of 1232 * extra fields. 1233 */ 1234static int diskstats_show(struct seq_file *seqf, void *v) 1235{ 1236 struct gendisk *gp = v; 1237 struct block_device *hd; 1238 unsigned int inflight; 1239 struct disk_stats stat; 1240 unsigned long idx; 1241 1242 /* 1243 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) 1244 seq_puts(seqf, "major minor name" 1245 " rio rmerge rsect ruse wio wmerge " 1246 "wsect wuse running use aveq" 1247 "\n\n"); 1248 */ 1249 1250 rcu_read_lock(); 1251 xa_for_each(&gp->part_tbl, idx, hd) { 1252 if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) 1253 continue; 1254 if (queue_is_mq(gp->queue)) 1255 inflight = blk_mq_in_flight(gp->queue, hd); 1256 else 1257 inflight = part_in_flight(hd); 1258 1259 if (inflight) { 1260 part_stat_lock(); 1261 update_io_ticks(hd, jiffies, true); 1262 part_stat_unlock(); 1263 } 1264 part_stat_read_all(hd, &stat); 1265 seq_printf(seqf, "%4d %7d %pg " 1266 "%lu %lu %lu %u " 1267 "%lu %lu %lu %u " 1268 "%u %u %u " 1269 "%lu %lu %lu %u " 1270 "%lu %u" 1271 "\n", 1272 MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd, 1273 stat.ios[STAT_READ], 1274 stat.merges[STAT_READ], 1275 stat.sectors[STAT_READ], 1276 (unsigned int)div_u64(stat.nsecs[STAT_READ], 1277 NSEC_PER_MSEC), 1278 stat.ios[STAT_WRITE], 1279 stat.merges[STAT_WRITE], 1280 stat.sectors[STAT_WRITE], 1281 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], 1282 NSEC_PER_MSEC), 1283 inflight, 1284 jiffies_to_msecs(stat.io_ticks), 1285 (unsigned int)div_u64(stat.nsecs[STAT_READ] + 1286 stat.nsecs[STAT_WRITE] + 1287 stat.nsecs[STAT_DISCARD] + 1288 stat.nsecs[STAT_FLUSH], 1289 NSEC_PER_MSEC), 1290 stat.ios[STAT_DISCARD], 1291 stat.merges[STAT_DISCARD], 1292 stat.sectors[STAT_DISCARD], 1293 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], 1294 NSEC_PER_MSEC), 1295 stat.ios[STAT_FLUSH], 1296 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], 1297 NSEC_PER_MSEC) 1298 ); 1299 } 1300 rcu_read_unlock(); 1301 1302 return 0; 1303} 1304 1305static const struct seq_operations diskstats_op = { 1306 .start = disk_seqf_start, 1307 .next = disk_seqf_next, 1308 .stop = disk_seqf_stop, 1309 .show = diskstats_show 1310}; 1311 1312static int __init proc_genhd_init(void) 1313{ 1314 proc_create_seq("diskstats", 0, NULL, &diskstats_op); 1315 proc_create_seq("partitions", 0, NULL, &partitions_op); 1316 return 0; 1317} 1318module_init(proc_genhd_init); 1319#endif /* CONFIG_PROC_FS */ 1320 1321dev_t part_devt(struct gendisk *disk, u8 partno) 1322{ 1323 struct block_device *part; 1324 dev_t devt = 0; 1325 1326 rcu_read_lock(); 1327 part = xa_load(&disk->part_tbl, partno); 1328 if (part) 1329 devt = part->bd_dev; 1330 rcu_read_unlock(); 1331 1332 return devt; 1333} 1334 1335struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, 1336 struct lock_class_key *lkclass) 1337{ 1338 struct gendisk *disk; 1339 1340 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); 1341 if (!disk) 1342 return NULL; 1343 1344 if (bioset_init(&disk->bio_split, BIO_POOL_SIZE, 0, 0)) 1345 goto out_free_disk; 1346 1347 disk->bdi = bdi_alloc(node_id); 1348 if (!disk->bdi) 1349 goto out_free_bioset; 1350 1351 /* bdev_alloc() might need the queue, set before the first call */ 1352 disk->queue = q; 1353 1354 disk->part0 = bdev_alloc(disk, 0); 1355 if (!disk->part0) 1356 goto out_free_bdi; 1357 1358 disk->node_id = node_id; 1359 mutex_init(&disk->open_mutex); 1360 xa_init(&disk->part_tbl); 1361 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL)) 1362 goto out_destroy_part_tbl; 1363 1364 if (blkcg_init_disk(disk)) 1365 goto out_erase_part0; 1366 1367 rand_initialize_disk(disk); 1368 disk_to_dev(disk)->class = &block_class; 1369 disk_to_dev(disk)->type = &disk_type; 1370 device_initialize(disk_to_dev(disk)); 1371 inc_diskseq(disk); 1372 q->disk = disk; 1373 lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0); 1374#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED 1375 INIT_LIST_HEAD(&disk->slave_bdevs); 1376#endif 1377 return disk; 1378 1379out_erase_part0: 1380 xa_erase(&disk->part_tbl, 0); 1381out_destroy_part_tbl: 1382 xa_destroy(&disk->part_tbl); 1383 disk->part0->bd_disk = NULL; 1384 iput(disk->part0->bd_inode); 1385out_free_bdi: 1386 bdi_put(disk->bdi); 1387out_free_bioset: 1388 bioset_exit(&disk->bio_split); 1389out_free_disk: 1390 kfree(disk); 1391 return NULL; 1392} 1393 1394struct gendisk *__blk_alloc_disk(struct queue_limits *lim, int node, 1395 struct lock_class_key *lkclass) 1396{ 1397 struct queue_limits default_lim = { }; 1398 struct request_queue *q; 1399 struct gendisk *disk; 1400 1401 q = blk_alloc_queue(lim ? lim : &default_lim, node); 1402 if (IS_ERR(q)) 1403 return ERR_CAST(q); 1404 1405 disk = __alloc_disk_node(q, node, lkclass); 1406 if (!disk) { 1407 blk_put_queue(q); 1408 return ERR_PTR(-ENOMEM); 1409 } 1410 set_bit(GD_OWNS_QUEUE, &disk->state); 1411 return disk; 1412} 1413EXPORT_SYMBOL(__blk_alloc_disk); 1414 1415/** 1416 * put_disk - decrements the gendisk refcount 1417 * @disk: the struct gendisk to decrement the refcount for 1418 * 1419 * This decrements the refcount for the struct gendisk. When this reaches 0 1420 * we'll have disk_release() called. 1421 * 1422 * Note: for blk-mq disk put_disk must be called before freeing the tag_set 1423 * when handling probe errors (that is before add_disk() is called). 1424 * 1425 * Context: Any context, but the last reference must not be dropped from 1426 * atomic context. 1427 */ 1428void put_disk(struct gendisk *disk) 1429{ 1430 if (disk) 1431 put_device(disk_to_dev(disk)); 1432} 1433EXPORT_SYMBOL(put_disk); 1434 1435static void set_disk_ro_uevent(struct gendisk *gd, int ro) 1436{ 1437 char event[] = "DISK_RO=1"; 1438 char *envp[] = { event, NULL }; 1439 1440 if (!ro) 1441 event[8] = '0'; 1442 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); 1443} 1444 1445/** 1446 * set_disk_ro - set a gendisk read-only 1447 * @disk: gendisk to operate on 1448 * @read_only: %true to set the disk read-only, %false set the disk read/write 1449 * 1450 * This function is used to indicate whether a given disk device should have its 1451 * read-only flag set. set_disk_ro() is typically used by device drivers to 1452 * indicate whether the underlying physical device is write-protected. 1453 */ 1454void set_disk_ro(struct gendisk *disk, bool read_only) 1455{ 1456 if (read_only) { 1457 if (test_and_set_bit(GD_READ_ONLY, &disk->state)) 1458 return; 1459 } else { 1460 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state)) 1461 return; 1462 } 1463 set_disk_ro_uevent(disk, read_only); 1464} 1465EXPORT_SYMBOL(set_disk_ro); 1466 1467void inc_diskseq(struct gendisk *disk) 1468{ 1469 disk->diskseq = atomic64_inc_return(&diskseq); 1470} 1471