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 "blk-throttle.h" 29 30 #include "blk.h" 31 #include "blk-mq-sched.h" 32 #include "blk-rq-qos.h" 33 #include "blk-cgroup.h" 34 35 static struct kobject *block_depr; 36 37 /* 38 * Unique, monotonically increasing sequential number associated with block 39 * devices instances (i.e. incremented each time a device is attached). 40 * Associating uevents with block devices in userspace is difficult and racy: 41 * the uevent netlink socket is lossy, and on slow and overloaded systems has 42 * a very high latency. 43 * Block devices do not have exclusive owners in userspace, any process can set 44 * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0 45 * can be reused again and again). 46 * A userspace process setting up a block device and watching for its events 47 * cannot thus reliably tell whether an event relates to the device it just set 48 * up or another earlier instance with the same name. 49 * This sequential number allows userspace processes to solve this problem, and 50 * uniquely associate an uevent to the lifetime to a device. 51 */ 52 static atomic64_t diskseq; 53 54 /* for extended dynamic devt allocation, currently only one major is used */ 55 #define NR_EXT_DEVT (1 << MINORBITS) 56 static DEFINE_IDA(ext_devt_ida); 57 58 void set_capacity(struct gendisk *disk, sector_t sectors) 59 { 60 struct block_device *bdev = disk->part0; 61 62 spin_lock(&bdev->bd_size_lock); 63 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); 64 bdev->bd_nr_sectors = sectors; 65 spin_unlock(&bdev->bd_size_lock); 66 } 67 EXPORT_SYMBOL(set_capacity); 68 69 /* 70 * Set disk capacity and notify if the size is not currently zero and will not 71 * be set to zero. Returns true if a uevent was sent, otherwise false. 72 */ 73 bool set_capacity_and_notify(struct gendisk *disk, sector_t size) 74 { 75 sector_t capacity = get_capacity(disk); 76 char *envp[] = { "RESIZE=1", NULL }; 77 78 set_capacity(disk, size); 79 80 /* 81 * Only print a message and send a uevent if the gendisk is user visible 82 * and alive. This avoids spamming the log and udev when setting the 83 * initial capacity during probing. 84 */ 85 if (size == capacity || 86 !disk_live(disk) || 87 (disk->flags & GENHD_FL_HIDDEN)) 88 return false; 89 90 pr_info("%s: detected capacity change from %lld to %lld\n", 91 disk->disk_name, capacity, size); 92 93 /* 94 * Historically we did not send a uevent for changes to/from an empty 95 * device. 96 */ 97 if (!capacity || !size) 98 return false; 99 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); 100 return true; 101 } 102 EXPORT_SYMBOL_GPL(set_capacity_and_notify); 103 104 static void part_stat_read_all(struct block_device *part, 105 struct disk_stats *stat) 106 { 107 int cpu; 108 109 memset(stat, 0, sizeof(struct disk_stats)); 110 for_each_possible_cpu(cpu) { 111 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu); 112 int group; 113 114 for (group = 0; group < NR_STAT_GROUPS; group++) { 115 stat->nsecs[group] += ptr->nsecs[group]; 116 stat->sectors[group] += ptr->sectors[group]; 117 stat->ios[group] += ptr->ios[group]; 118 stat->merges[group] += ptr->merges[group]; 119 } 120 121 stat->io_ticks += ptr->io_ticks; 122 } 123 } 124 125 static unsigned int part_in_flight(struct block_device *part) 126 { 127 unsigned int inflight = 0; 128 int cpu; 129 130 for_each_possible_cpu(cpu) { 131 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) + 132 part_stat_local_read_cpu(part, in_flight[1], cpu); 133 } 134 if ((int)inflight < 0) 135 inflight = 0; 136 137 return inflight; 138 } 139 140 static void part_in_flight_rw(struct block_device *part, 141 unsigned int inflight[2]) 142 { 143 int cpu; 144 145 inflight[0] = 0; 146 inflight[1] = 0; 147 for_each_possible_cpu(cpu) { 148 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu); 149 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu); 150 } 151 if ((int)inflight[0] < 0) 152 inflight[0] = 0; 153 if ((int)inflight[1] < 0) 154 inflight[1] = 0; 155 } 156 157 /* 158 * Can be deleted altogether. Later. 159 * 160 */ 161 #define BLKDEV_MAJOR_HASH_SIZE 255 162 static struct blk_major_name { 163 struct blk_major_name *next; 164 int major; 165 char name[16]; 166 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD 167 void (*probe)(dev_t devt); 168 #endif 169 } *major_names[BLKDEV_MAJOR_HASH_SIZE]; 170 static DEFINE_MUTEX(major_names_lock); 171 static DEFINE_SPINLOCK(major_names_spinlock); 172 173 /* index in the above - for now: assume no multimajor ranges */ 174 static inline int major_to_index(unsigned major) 175 { 176 return major % BLKDEV_MAJOR_HASH_SIZE; 177 } 178 179 #ifdef CONFIG_PROC_FS 180 void blkdev_show(struct seq_file *seqf, off_t offset) 181 { 182 struct blk_major_name *dp; 183 184 spin_lock(&major_names_spinlock); 185 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next) 186 if (dp->major == offset) 187 seq_printf(seqf, "%3d %s\n", dp->major, dp->name); 188 spin_unlock(&major_names_spinlock); 189 } 190 #endif /* CONFIG_PROC_FS */ 191 192 /** 193 * __register_blkdev - register a new block device 194 * 195 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If 196 * @major = 0, try to allocate any unused major number. 197 * @name: the name of the new block device as a zero terminated string 198 * @probe: pre-devtmpfs / pre-udev callback used to create disks when their 199 * pre-created device node is accessed. When a probe call uses 200 * add_disk() and it fails the driver must cleanup resources. This 201 * interface may soon be removed. 202 * 203 * The @name must be unique within the system. 204 * 205 * The return value depends on the @major input parameter: 206 * 207 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1] 208 * then the function returns zero on success, or a negative error code 209 * - if any unused major number was requested with @major = 0 parameter 210 * then the return value is the allocated major number in range 211 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise 212 * 213 * See Documentation/admin-guide/devices.txt for the list of allocated 214 * major numbers. 215 * 216 * Use register_blkdev instead for any new code. 217 */ 218 int __register_blkdev(unsigned int major, const char *name, 219 void (*probe)(dev_t devt)) 220 { 221 struct blk_major_name **n, *p; 222 int index, ret = 0; 223 224 mutex_lock(&major_names_lock); 225 226 /* temporary */ 227 if (major == 0) { 228 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { 229 if (major_names[index] == NULL) 230 break; 231 } 232 233 if (index == 0) { 234 printk("%s: failed to get major for %s\n", 235 __func__, name); 236 ret = -EBUSY; 237 goto out; 238 } 239 major = index; 240 ret = major; 241 } 242 243 if (major >= BLKDEV_MAJOR_MAX) { 244 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n", 245 __func__, major, BLKDEV_MAJOR_MAX-1, name); 246 247 ret = -EINVAL; 248 goto out; 249 } 250 251 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); 252 if (p == NULL) { 253 ret = -ENOMEM; 254 goto out; 255 } 256 257 p->major = major; 258 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD 259 p->probe = probe; 260 #endif 261 strlcpy(p->name, name, sizeof(p->name)); 262 p->next = NULL; 263 index = major_to_index(major); 264 265 spin_lock(&major_names_spinlock); 266 for (n = &major_names[index]; *n; n = &(*n)->next) { 267 if ((*n)->major == major) 268 break; 269 } 270 if (!*n) 271 *n = p; 272 else 273 ret = -EBUSY; 274 spin_unlock(&major_names_spinlock); 275 276 if (ret < 0) { 277 printk("register_blkdev: cannot get major %u for %s\n", 278 major, name); 279 kfree(p); 280 } 281 out: 282 mutex_unlock(&major_names_lock); 283 return ret; 284 } 285 EXPORT_SYMBOL(__register_blkdev); 286 287 void unregister_blkdev(unsigned int major, const char *name) 288 { 289 struct blk_major_name **n; 290 struct blk_major_name *p = NULL; 291 int index = major_to_index(major); 292 293 mutex_lock(&major_names_lock); 294 spin_lock(&major_names_spinlock); 295 for (n = &major_names[index]; *n; n = &(*n)->next) 296 if ((*n)->major == major) 297 break; 298 if (!*n || strcmp((*n)->name, name)) { 299 WARN_ON(1); 300 } else { 301 p = *n; 302 *n = p->next; 303 } 304 spin_unlock(&major_names_spinlock); 305 mutex_unlock(&major_names_lock); 306 kfree(p); 307 } 308 309 EXPORT_SYMBOL(unregister_blkdev); 310 311 int blk_alloc_ext_minor(void) 312 { 313 int idx; 314 315 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT - 1, GFP_KERNEL); 316 if (idx == -ENOSPC) 317 return -EBUSY; 318 return idx; 319 } 320 321 void blk_free_ext_minor(unsigned int minor) 322 { 323 ida_free(&ext_devt_ida, minor); 324 } 325 326 static char *bdevt_str(dev_t devt, char *buf) 327 { 328 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) { 329 char tbuf[BDEVT_SIZE]; 330 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt)); 331 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf); 332 } else 333 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt)); 334 335 return buf; 336 } 337 338 void disk_uevent(struct gendisk *disk, enum kobject_action action) 339 { 340 struct block_device *part; 341 unsigned long idx; 342 343 rcu_read_lock(); 344 xa_for_each(&disk->part_tbl, idx, part) { 345 if (bdev_is_partition(part) && !bdev_nr_sectors(part)) 346 continue; 347 if (!kobject_get_unless_zero(&part->bd_device.kobj)) 348 continue; 349 350 rcu_read_unlock(); 351 kobject_uevent(bdev_kobj(part), action); 352 put_device(&part->bd_device); 353 rcu_read_lock(); 354 } 355 rcu_read_unlock(); 356 } 357 EXPORT_SYMBOL_GPL(disk_uevent); 358 359 int disk_scan_partitions(struct gendisk *disk, fmode_t mode) 360 { 361 struct block_device *bdev; 362 363 if (disk->flags & (GENHD_FL_NO_PART | GENHD_FL_HIDDEN)) 364 return -EINVAL; 365 if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) 366 return -EINVAL; 367 if (disk->open_partitions) 368 return -EBUSY; 369 370 set_bit(GD_NEED_PART_SCAN, &disk->state); 371 bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL); 372 if (IS_ERR(bdev)) 373 return PTR_ERR(bdev); 374 blkdev_put(bdev, mode); 375 return 0; 376 } 377 378 /** 379 * device_add_disk - add disk information to kernel list 380 * @parent: parent device for the disk 381 * @disk: per-device partitioning information 382 * @groups: Additional per-device sysfs groups 383 * 384 * This function registers the partitioning information in @disk 385 * with the kernel. 386 */ 387 int __must_check device_add_disk(struct device *parent, struct gendisk *disk, 388 const struct attribute_group **groups) 389 390 { 391 struct device *ddev = disk_to_dev(disk); 392 int ret; 393 394 /* Only makes sense for bio-based to set ->poll_bio */ 395 if (queue_is_mq(disk->queue) && disk->fops->poll_bio) 396 return -EINVAL; 397 398 /* 399 * The disk queue should now be all set with enough information about 400 * the device for the elevator code to pick an adequate default 401 * elevator if one is needed, that is, for devices requesting queue 402 * registration. 403 */ 404 elevator_init_mq(disk->queue); 405 406 /* 407 * If the driver provides an explicit major number it also must provide 408 * the number of minors numbers supported, and those will be used to 409 * setup the gendisk. 410 * Otherwise just allocate the device numbers for both the whole device 411 * and all partitions from the extended dev_t space. 412 */ 413 if (disk->major) { 414 if (WARN_ON(!disk->minors)) 415 return -EINVAL; 416 417 if (disk->minors > DISK_MAX_PARTS) { 418 pr_err("block: can't allocate more than %d partitions\n", 419 DISK_MAX_PARTS); 420 disk->minors = DISK_MAX_PARTS; 421 } 422 if (disk->first_minor + disk->minors > MINORMASK + 1) 423 return -EINVAL; 424 } else { 425 if (WARN_ON(disk->minors)) 426 return -EINVAL; 427 428 ret = blk_alloc_ext_minor(); 429 if (ret < 0) 430 return ret; 431 disk->major = BLOCK_EXT_MAJOR; 432 disk->first_minor = ret; 433 } 434 435 /* delay uevents, until we scanned partition table */ 436 dev_set_uevent_suppress(ddev, 1); 437 438 ddev->parent = parent; 439 ddev->groups = groups; 440 dev_set_name(ddev, "%s", disk->disk_name); 441 if (!(disk->flags & GENHD_FL_HIDDEN)) 442 ddev->devt = MKDEV(disk->major, disk->first_minor); 443 ret = device_add(ddev); 444 if (ret) 445 goto out_free_ext_minor; 446 447 ret = disk_alloc_events(disk); 448 if (ret) 449 goto out_device_del; 450 451 if (!sysfs_deprecated) { 452 ret = sysfs_create_link(block_depr, &ddev->kobj, 453 kobject_name(&ddev->kobj)); 454 if (ret) 455 goto out_device_del; 456 } 457 458 /* 459 * avoid probable deadlock caused by allocating memory with 460 * GFP_KERNEL in runtime_resume callback of its all ancestor 461 * devices 462 */ 463 pm_runtime_set_memalloc_noio(ddev, true); 464 465 ret = blk_integrity_add(disk); 466 if (ret) 467 goto out_del_block_link; 468 469 disk->part0->bd_holder_dir = 470 kobject_create_and_add("holders", &ddev->kobj); 471 if (!disk->part0->bd_holder_dir) { 472 ret = -ENOMEM; 473 goto out_del_integrity; 474 } 475 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); 476 if (!disk->slave_dir) { 477 ret = -ENOMEM; 478 goto out_put_holder_dir; 479 } 480 481 ret = bd_register_pending_holders(disk); 482 if (ret < 0) 483 goto out_put_slave_dir; 484 485 ret = blk_register_queue(disk); 486 if (ret) 487 goto out_put_slave_dir; 488 489 if (!(disk->flags & GENHD_FL_HIDDEN)) { 490 ret = bdi_register(disk->bdi, "%u:%u", 491 disk->major, disk->first_minor); 492 if (ret) 493 goto out_unregister_queue; 494 bdi_set_owner(disk->bdi, ddev); 495 ret = sysfs_create_link(&ddev->kobj, 496 &disk->bdi->dev->kobj, "bdi"); 497 if (ret) 498 goto out_unregister_bdi; 499 500 bdev_add(disk->part0, ddev->devt); 501 if (get_capacity(disk)) 502 disk_scan_partitions(disk, FMODE_READ); 503 504 /* 505 * Announce the disk and partitions after all partitions are 506 * created. (for hidden disks uevents remain suppressed forever) 507 */ 508 dev_set_uevent_suppress(ddev, 0); 509 disk_uevent(disk, KOBJ_ADD); 510 } 511 512 disk_update_readahead(disk); 513 disk_add_events(disk); 514 set_bit(GD_ADDED, &disk->state); 515 return 0; 516 517 out_unregister_bdi: 518 if (!(disk->flags & GENHD_FL_HIDDEN)) 519 bdi_unregister(disk->bdi); 520 out_unregister_queue: 521 blk_unregister_queue(disk); 522 out_put_slave_dir: 523 kobject_put(disk->slave_dir); 524 out_put_holder_dir: 525 kobject_put(disk->part0->bd_holder_dir); 526 out_del_integrity: 527 blk_integrity_del(disk); 528 out_del_block_link: 529 if (!sysfs_deprecated) 530 sysfs_remove_link(block_depr, dev_name(ddev)); 531 out_device_del: 532 device_del(ddev); 533 out_free_ext_minor: 534 if (disk->major == BLOCK_EXT_MAJOR) 535 blk_free_ext_minor(disk->first_minor); 536 return ret; 537 } 538 EXPORT_SYMBOL(device_add_disk); 539 540 /** 541 * blk_mark_disk_dead - mark a disk as dead 542 * @disk: disk to mark as dead 543 * 544 * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O 545 * to this disk. 546 */ 547 void blk_mark_disk_dead(struct gendisk *disk) 548 { 549 set_bit(GD_DEAD, &disk->state); 550 blk_queue_start_drain(disk->queue); 551 } 552 EXPORT_SYMBOL_GPL(blk_mark_disk_dead); 553 554 /** 555 * del_gendisk - remove the gendisk 556 * @disk: the struct gendisk to remove 557 * 558 * Removes the gendisk and all its associated resources. This deletes the 559 * partitions associated with the gendisk, and unregisters the associated 560 * request_queue. 561 * 562 * This is the counter to the respective __device_add_disk() call. 563 * 564 * The final removal of the struct gendisk happens when its refcount reaches 0 565 * with put_disk(), which should be called after del_gendisk(), if 566 * __device_add_disk() was used. 567 * 568 * Drivers exist which depend on the release of the gendisk to be synchronous, 569 * it should not be deferred. 570 * 571 * Context: can sleep 572 */ 573 void del_gendisk(struct gendisk *disk) 574 { 575 struct request_queue *q = disk->queue; 576 577 might_sleep(); 578 579 if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN))) 580 return; 581 582 blk_integrity_del(disk); 583 disk_del_events(disk); 584 585 mutex_lock(&disk->open_mutex); 586 remove_inode_hash(disk->part0->bd_inode); 587 blk_drop_partitions(disk); 588 mutex_unlock(&disk->open_mutex); 589 590 fsync_bdev(disk->part0); 591 __invalidate_device(disk->part0, true); 592 593 /* 594 * Fail any new I/O. 595 */ 596 set_bit(GD_DEAD, &disk->state); 597 if (test_bit(GD_OWNS_QUEUE, &disk->state)) 598 blk_queue_flag_set(QUEUE_FLAG_DYING, q); 599 set_capacity(disk, 0); 600 601 /* 602 * Prevent new I/O from crossing bio_queue_enter(). 603 */ 604 blk_queue_start_drain(q); 605 606 if (!(disk->flags & GENHD_FL_HIDDEN)) { 607 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); 608 609 /* 610 * Unregister bdi before releasing device numbers (as they can 611 * get reused and we'd get clashes in sysfs). 612 */ 613 bdi_unregister(disk->bdi); 614 } 615 616 blk_unregister_queue(disk); 617 618 kobject_put(disk->part0->bd_holder_dir); 619 kobject_put(disk->slave_dir); 620 621 part_stat_set_all(disk->part0, 0); 622 disk->part0->bd_stamp = 0; 623 if (!sysfs_deprecated) 624 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); 625 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); 626 device_del(disk_to_dev(disk)); 627 628 blk_mq_freeze_queue_wait(q); 629 630 blk_throtl_cancel_bios(disk->queue); 631 632 blk_sync_queue(q); 633 blk_flush_integrity(); 634 blk_mq_cancel_work_sync(q); 635 636 blk_mq_quiesce_queue(q); 637 if (q->elevator) { 638 mutex_lock(&q->sysfs_lock); 639 elevator_exit(q); 640 mutex_unlock(&q->sysfs_lock); 641 } 642 rq_qos_exit(q); 643 blk_mq_unquiesce_queue(q); 644 645 /* 646 * If the disk does not own the queue, allow using passthrough requests 647 * again. Else leave the queue frozen to fail all I/O. 648 */ 649 if (!test_bit(GD_OWNS_QUEUE, &disk->state)) { 650 blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); 651 __blk_mq_unfreeze_queue(q, true); 652 } else { 653 if (queue_is_mq(q)) 654 blk_mq_exit_queue(q); 655 } 656 } 657 EXPORT_SYMBOL(del_gendisk); 658 659 /** 660 * invalidate_disk - invalidate the disk 661 * @disk: the struct gendisk to invalidate 662 * 663 * A helper to invalidates the disk. It will clean the disk's associated 664 * buffer/page caches and reset its internal states so that the disk 665 * can be reused by the drivers. 666 * 667 * Context: can sleep 668 */ 669 void invalidate_disk(struct gendisk *disk) 670 { 671 struct block_device *bdev = disk->part0; 672 673 invalidate_bdev(bdev); 674 bdev->bd_inode->i_mapping->wb_err = 0; 675 set_capacity(disk, 0); 676 } 677 EXPORT_SYMBOL(invalidate_disk); 678 679 /* sysfs access to bad-blocks list. */ 680 static ssize_t disk_badblocks_show(struct device *dev, 681 struct device_attribute *attr, 682 char *page) 683 { 684 struct gendisk *disk = dev_to_disk(dev); 685 686 if (!disk->bb) 687 return sprintf(page, "\n"); 688 689 return badblocks_show(disk->bb, page, 0); 690 } 691 692 static ssize_t disk_badblocks_store(struct device *dev, 693 struct device_attribute *attr, 694 const char *page, size_t len) 695 { 696 struct gendisk *disk = dev_to_disk(dev); 697 698 if (!disk->bb) 699 return -ENXIO; 700 701 return badblocks_store(disk->bb, page, len, 0); 702 } 703 704 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD 705 void blk_request_module(dev_t devt) 706 { 707 unsigned int major = MAJOR(devt); 708 struct blk_major_name **n; 709 710 mutex_lock(&major_names_lock); 711 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) { 712 if ((*n)->major == major && (*n)->probe) { 713 (*n)->probe(devt); 714 mutex_unlock(&major_names_lock); 715 return; 716 } 717 } 718 mutex_unlock(&major_names_lock); 719 720 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) 721 /* Make old-style 2.4 aliases work */ 722 request_module("block-major-%d", MAJOR(devt)); 723 } 724 #endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */ 725 726 /* 727 * print a full list of all partitions - intended for places where the root 728 * filesystem can't be mounted and thus to give the victim some idea of what 729 * went wrong 730 */ 731 void __init printk_all_partitions(void) 732 { 733 struct class_dev_iter iter; 734 struct device *dev; 735 736 class_dev_iter_init(&iter, &block_class, NULL, &disk_type); 737 while ((dev = class_dev_iter_next(&iter))) { 738 struct gendisk *disk = dev_to_disk(dev); 739 struct block_device *part; 740 char devt_buf[BDEVT_SIZE]; 741 unsigned long idx; 742 743 /* 744 * Don't show empty devices or things that have been 745 * suppressed 746 */ 747 if (get_capacity(disk) == 0 || (disk->flags & GENHD_FL_HIDDEN)) 748 continue; 749 750 /* 751 * Note, unlike /proc/partitions, I am showing the numbers in 752 * hex - the same format as the root= option takes. 753 */ 754 rcu_read_lock(); 755 xa_for_each(&disk->part_tbl, idx, part) { 756 if (!bdev_nr_sectors(part)) 757 continue; 758 printk("%s%s %10llu %pg %s", 759 bdev_is_partition(part) ? " " : "", 760 bdevt_str(part->bd_dev, devt_buf), 761 bdev_nr_sectors(part) >> 1, part, 762 part->bd_meta_info ? 763 part->bd_meta_info->uuid : ""); 764 if (bdev_is_partition(part)) 765 printk("\n"); 766 else if (dev->parent && dev->parent->driver) 767 printk(" driver: %s\n", 768 dev->parent->driver->name); 769 else 770 printk(" (driver?)\n"); 771 } 772 rcu_read_unlock(); 773 } 774 class_dev_iter_exit(&iter); 775 } 776 777 #ifdef CONFIG_PROC_FS 778 /* iterator */ 779 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) 780 { 781 loff_t skip = *pos; 782 struct class_dev_iter *iter; 783 struct device *dev; 784 785 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 786 if (!iter) 787 return ERR_PTR(-ENOMEM); 788 789 seqf->private = iter; 790 class_dev_iter_init(iter, &block_class, NULL, &disk_type); 791 do { 792 dev = class_dev_iter_next(iter); 793 if (!dev) 794 return NULL; 795 } while (skip--); 796 797 return dev_to_disk(dev); 798 } 799 800 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) 801 { 802 struct device *dev; 803 804 (*pos)++; 805 dev = class_dev_iter_next(seqf->private); 806 if (dev) 807 return dev_to_disk(dev); 808 809 return NULL; 810 } 811 812 static void disk_seqf_stop(struct seq_file *seqf, void *v) 813 { 814 struct class_dev_iter *iter = seqf->private; 815 816 /* stop is called even after start failed :-( */ 817 if (iter) { 818 class_dev_iter_exit(iter); 819 kfree(iter); 820 seqf->private = NULL; 821 } 822 } 823 824 static void *show_partition_start(struct seq_file *seqf, loff_t *pos) 825 { 826 void *p; 827 828 p = disk_seqf_start(seqf, pos); 829 if (!IS_ERR_OR_NULL(p) && !*pos) 830 seq_puts(seqf, "major minor #blocks name\n\n"); 831 return p; 832 } 833 834 static int show_partition(struct seq_file *seqf, void *v) 835 { 836 struct gendisk *sgp = v; 837 struct block_device *part; 838 unsigned long idx; 839 840 if (!get_capacity(sgp) || (sgp->flags & GENHD_FL_HIDDEN)) 841 return 0; 842 843 rcu_read_lock(); 844 xa_for_each(&sgp->part_tbl, idx, part) { 845 if (!bdev_nr_sectors(part)) 846 continue; 847 seq_printf(seqf, "%4d %7d %10llu %pg\n", 848 MAJOR(part->bd_dev), MINOR(part->bd_dev), 849 bdev_nr_sectors(part) >> 1, part); 850 } 851 rcu_read_unlock(); 852 return 0; 853 } 854 855 static const struct seq_operations partitions_op = { 856 .start = show_partition_start, 857 .next = disk_seqf_next, 858 .stop = disk_seqf_stop, 859 .show = show_partition 860 }; 861 #endif 862 863 static int __init genhd_device_init(void) 864 { 865 int error; 866 867 block_class.dev_kobj = sysfs_dev_block_kobj; 868 error = class_register(&block_class); 869 if (unlikely(error)) 870 return error; 871 blk_dev_init(); 872 873 register_blkdev(BLOCK_EXT_MAJOR, "blkext"); 874 875 /* create top-level block dir */ 876 if (!sysfs_deprecated) 877 block_depr = kobject_create_and_add("block", NULL); 878 return 0; 879 } 880 881 subsys_initcall(genhd_device_init); 882 883 static ssize_t disk_range_show(struct device *dev, 884 struct device_attribute *attr, char *buf) 885 { 886 struct gendisk *disk = dev_to_disk(dev); 887 888 return sprintf(buf, "%d\n", disk->minors); 889 } 890 891 static ssize_t disk_ext_range_show(struct device *dev, 892 struct device_attribute *attr, char *buf) 893 { 894 struct gendisk *disk = dev_to_disk(dev); 895 896 return sprintf(buf, "%d\n", 897 (disk->flags & GENHD_FL_NO_PART) ? 1 : DISK_MAX_PARTS); 898 } 899 900 static ssize_t disk_removable_show(struct device *dev, 901 struct device_attribute *attr, char *buf) 902 { 903 struct gendisk *disk = dev_to_disk(dev); 904 905 return sprintf(buf, "%d\n", 906 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); 907 } 908 909 static ssize_t disk_hidden_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_HIDDEN ? 1 : 0)); 916 } 917 918 static ssize_t disk_ro_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", get_disk_ro(disk) ? 1 : 0); 924 } 925 926 ssize_t part_size_show(struct device *dev, 927 struct device_attribute *attr, char *buf) 928 { 929 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev))); 930 } 931 932 ssize_t part_stat_show(struct device *dev, 933 struct device_attribute *attr, char *buf) 934 { 935 struct block_device *bdev = dev_to_bdev(dev); 936 struct request_queue *q = bdev_get_queue(bdev); 937 struct disk_stats stat; 938 unsigned int inflight; 939 940 if (queue_is_mq(q)) 941 inflight = blk_mq_in_flight(q, bdev); 942 else 943 inflight = part_in_flight(bdev); 944 945 if (inflight) { 946 part_stat_lock(); 947 update_io_ticks(bdev, jiffies, true); 948 part_stat_unlock(); 949 } 950 part_stat_read_all(bdev, &stat); 951 return sprintf(buf, 952 "%8lu %8lu %8llu %8u " 953 "%8lu %8lu %8llu %8u " 954 "%8u %8u %8u " 955 "%8lu %8lu %8llu %8u " 956 "%8lu %8u" 957 "\n", 958 stat.ios[STAT_READ], 959 stat.merges[STAT_READ], 960 (unsigned long long)stat.sectors[STAT_READ], 961 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC), 962 stat.ios[STAT_WRITE], 963 stat.merges[STAT_WRITE], 964 (unsigned long long)stat.sectors[STAT_WRITE], 965 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC), 966 inflight, 967 jiffies_to_msecs(stat.io_ticks), 968 (unsigned int)div_u64(stat.nsecs[STAT_READ] + 969 stat.nsecs[STAT_WRITE] + 970 stat.nsecs[STAT_DISCARD] + 971 stat.nsecs[STAT_FLUSH], 972 NSEC_PER_MSEC), 973 stat.ios[STAT_DISCARD], 974 stat.merges[STAT_DISCARD], 975 (unsigned long long)stat.sectors[STAT_DISCARD], 976 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC), 977 stat.ios[STAT_FLUSH], 978 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC)); 979 } 980 981 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, 982 char *buf) 983 { 984 struct block_device *bdev = dev_to_bdev(dev); 985 struct request_queue *q = bdev_get_queue(bdev); 986 unsigned int inflight[2]; 987 988 if (queue_is_mq(q)) 989 blk_mq_in_flight_rw(q, bdev, inflight); 990 else 991 part_in_flight_rw(bdev, inflight); 992 993 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]); 994 } 995 996 static ssize_t disk_capability_show(struct device *dev, 997 struct device_attribute *attr, char *buf) 998 { 999 struct gendisk *disk = dev_to_disk(dev); 1000 1001 return sprintf(buf, "%x\n", disk->flags); 1002 } 1003 1004 static ssize_t disk_alignment_offset_show(struct device *dev, 1005 struct device_attribute *attr, 1006 char *buf) 1007 { 1008 struct gendisk *disk = dev_to_disk(dev); 1009 1010 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0)); 1011 } 1012 1013 static ssize_t disk_discard_alignment_show(struct device *dev, 1014 struct device_attribute *attr, 1015 char *buf) 1016 { 1017 struct gendisk *disk = dev_to_disk(dev); 1018 1019 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0)); 1020 } 1021 1022 static ssize_t diskseq_show(struct device *dev, 1023 struct device_attribute *attr, char *buf) 1024 { 1025 struct gendisk *disk = dev_to_disk(dev); 1026 1027 return sprintf(buf, "%llu\n", disk->diskseq); 1028 } 1029 1030 static DEVICE_ATTR(range, 0444, disk_range_show, NULL); 1031 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL); 1032 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL); 1033 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL); 1034 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL); 1035 static DEVICE_ATTR(size, 0444, part_size_show, NULL); 1036 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL); 1037 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL); 1038 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL); 1039 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL); 1040 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL); 1041 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store); 1042 static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL); 1043 1044 #ifdef CONFIG_FAIL_MAKE_REQUEST 1045 ssize_t part_fail_show(struct device *dev, 1046 struct device_attribute *attr, char *buf) 1047 { 1048 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail); 1049 } 1050 1051 ssize_t part_fail_store(struct device *dev, 1052 struct device_attribute *attr, 1053 const char *buf, size_t count) 1054 { 1055 int i; 1056 1057 if (count > 0 && sscanf(buf, "%d", &i) > 0) 1058 dev_to_bdev(dev)->bd_make_it_fail = i; 1059 1060 return count; 1061 } 1062 1063 static struct device_attribute dev_attr_fail = 1064 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store); 1065 #endif /* CONFIG_FAIL_MAKE_REQUEST */ 1066 1067 #ifdef CONFIG_FAIL_IO_TIMEOUT 1068 static struct device_attribute dev_attr_fail_timeout = 1069 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store); 1070 #endif 1071 1072 static struct attribute *disk_attrs[] = { 1073 &dev_attr_range.attr, 1074 &dev_attr_ext_range.attr, 1075 &dev_attr_removable.attr, 1076 &dev_attr_hidden.attr, 1077 &dev_attr_ro.attr, 1078 &dev_attr_size.attr, 1079 &dev_attr_alignment_offset.attr, 1080 &dev_attr_discard_alignment.attr, 1081 &dev_attr_capability.attr, 1082 &dev_attr_stat.attr, 1083 &dev_attr_inflight.attr, 1084 &dev_attr_badblocks.attr, 1085 &dev_attr_events.attr, 1086 &dev_attr_events_async.attr, 1087 &dev_attr_events_poll_msecs.attr, 1088 &dev_attr_diskseq.attr, 1089 #ifdef CONFIG_FAIL_MAKE_REQUEST 1090 &dev_attr_fail.attr, 1091 #endif 1092 #ifdef CONFIG_FAIL_IO_TIMEOUT 1093 &dev_attr_fail_timeout.attr, 1094 #endif 1095 NULL 1096 }; 1097 1098 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n) 1099 { 1100 struct device *dev = container_of(kobj, typeof(*dev), kobj); 1101 struct gendisk *disk = dev_to_disk(dev); 1102 1103 if (a == &dev_attr_badblocks.attr && !disk->bb) 1104 return 0; 1105 return a->mode; 1106 } 1107 1108 static struct attribute_group disk_attr_group = { 1109 .attrs = disk_attrs, 1110 .is_visible = disk_visible, 1111 }; 1112 1113 static const struct attribute_group *disk_attr_groups[] = { 1114 &disk_attr_group, 1115 #ifdef CONFIG_BLK_DEV_IO_TRACE 1116 &blk_trace_attr_group, 1117 #endif 1118 NULL 1119 }; 1120 1121 /** 1122 * disk_release - releases all allocated resources of the gendisk 1123 * @dev: the device representing this disk 1124 * 1125 * This function releases all allocated resources of the gendisk. 1126 * 1127 * Drivers which used __device_add_disk() have a gendisk with a request_queue 1128 * assigned. Since the request_queue sits on top of the gendisk for these 1129 * drivers we also call blk_put_queue() for them, and we expect the 1130 * request_queue refcount to reach 0 at this point, and so the request_queue 1131 * will also be freed prior to the disk. 1132 * 1133 * Context: can sleep 1134 */ 1135 static void disk_release(struct device *dev) 1136 { 1137 struct gendisk *disk = dev_to_disk(dev); 1138 1139 might_sleep(); 1140 WARN_ON_ONCE(disk_live(disk)); 1141 1142 /* 1143 * To undo the all initialization from blk_mq_init_allocated_queue in 1144 * case of a probe failure where add_disk is never called we have to 1145 * call blk_mq_exit_queue here. We can't do this for the more common 1146 * teardown case (yet) as the tagset can be gone by the time the disk 1147 * is released once it was added. 1148 */ 1149 if (queue_is_mq(disk->queue) && 1150 test_bit(GD_OWNS_QUEUE, &disk->state) && 1151 !test_bit(GD_ADDED, &disk->state)) 1152 blk_mq_exit_queue(disk->queue); 1153 1154 blkcg_exit_queue(disk->queue); 1155 bioset_exit(&disk->bio_split); 1156 1157 disk_release_events(disk); 1158 kfree(disk->random); 1159 disk_free_zone_bitmaps(disk); 1160 xa_destroy(&disk->part_tbl); 1161 1162 disk->queue->disk = NULL; 1163 blk_put_queue(disk->queue); 1164 1165 if (test_bit(GD_ADDED, &disk->state) && disk->fops->free_disk) 1166 disk->fops->free_disk(disk); 1167 1168 iput(disk->part0->bd_inode); /* frees the disk */ 1169 } 1170 1171 static int block_uevent(struct device *dev, struct kobj_uevent_env *env) 1172 { 1173 struct gendisk *disk = dev_to_disk(dev); 1174 1175 return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq); 1176 } 1177 1178 struct class block_class = { 1179 .name = "block", 1180 .dev_uevent = block_uevent, 1181 }; 1182 1183 static char *block_devnode(struct device *dev, umode_t *mode, 1184 kuid_t *uid, kgid_t *gid) 1185 { 1186 struct gendisk *disk = dev_to_disk(dev); 1187 1188 if (disk->fops->devnode) 1189 return disk->fops->devnode(disk, mode); 1190 return NULL; 1191 } 1192 1193 const struct device_type disk_type = { 1194 .name = "disk", 1195 .groups = disk_attr_groups, 1196 .release = disk_release, 1197 .devnode = block_devnode, 1198 }; 1199 1200 #ifdef CONFIG_PROC_FS 1201 /* 1202 * aggregate disk stat collector. Uses the same stats that the sysfs 1203 * entries do, above, but makes them available through one seq_file. 1204 * 1205 * The output looks suspiciously like /proc/partitions with a bunch of 1206 * extra fields. 1207 */ 1208 static int diskstats_show(struct seq_file *seqf, void *v) 1209 { 1210 struct gendisk *gp = v; 1211 struct block_device *hd; 1212 unsigned int inflight; 1213 struct disk_stats stat; 1214 unsigned long idx; 1215 1216 /* 1217 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) 1218 seq_puts(seqf, "major minor name" 1219 " rio rmerge rsect ruse wio wmerge " 1220 "wsect wuse running use aveq" 1221 "\n\n"); 1222 */ 1223 1224 rcu_read_lock(); 1225 xa_for_each(&gp->part_tbl, idx, hd) { 1226 if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) 1227 continue; 1228 if (queue_is_mq(gp->queue)) 1229 inflight = blk_mq_in_flight(gp->queue, hd); 1230 else 1231 inflight = part_in_flight(hd); 1232 1233 if (inflight) { 1234 part_stat_lock(); 1235 update_io_ticks(hd, jiffies, true); 1236 part_stat_unlock(); 1237 } 1238 part_stat_read_all(hd, &stat); 1239 seq_printf(seqf, "%4d %7d %pg " 1240 "%lu %lu %lu %u " 1241 "%lu %lu %lu %u " 1242 "%u %u %u " 1243 "%lu %lu %lu %u " 1244 "%lu %u" 1245 "\n", 1246 MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd, 1247 stat.ios[STAT_READ], 1248 stat.merges[STAT_READ], 1249 stat.sectors[STAT_READ], 1250 (unsigned int)div_u64(stat.nsecs[STAT_READ], 1251 NSEC_PER_MSEC), 1252 stat.ios[STAT_WRITE], 1253 stat.merges[STAT_WRITE], 1254 stat.sectors[STAT_WRITE], 1255 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], 1256 NSEC_PER_MSEC), 1257 inflight, 1258 jiffies_to_msecs(stat.io_ticks), 1259 (unsigned int)div_u64(stat.nsecs[STAT_READ] + 1260 stat.nsecs[STAT_WRITE] + 1261 stat.nsecs[STAT_DISCARD] + 1262 stat.nsecs[STAT_FLUSH], 1263 NSEC_PER_MSEC), 1264 stat.ios[STAT_DISCARD], 1265 stat.merges[STAT_DISCARD], 1266 stat.sectors[STAT_DISCARD], 1267 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], 1268 NSEC_PER_MSEC), 1269 stat.ios[STAT_FLUSH], 1270 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], 1271 NSEC_PER_MSEC) 1272 ); 1273 } 1274 rcu_read_unlock(); 1275 1276 return 0; 1277 } 1278 1279 static const struct seq_operations diskstats_op = { 1280 .start = disk_seqf_start, 1281 .next = disk_seqf_next, 1282 .stop = disk_seqf_stop, 1283 .show = diskstats_show 1284 }; 1285 1286 static int __init proc_genhd_init(void) 1287 { 1288 proc_create_seq("diskstats", 0, NULL, &diskstats_op); 1289 proc_create_seq("partitions", 0, NULL, &partitions_op); 1290 return 0; 1291 } 1292 module_init(proc_genhd_init); 1293 #endif /* CONFIG_PROC_FS */ 1294 1295 dev_t part_devt(struct gendisk *disk, u8 partno) 1296 { 1297 struct block_device *part; 1298 dev_t devt = 0; 1299 1300 rcu_read_lock(); 1301 part = xa_load(&disk->part_tbl, partno); 1302 if (part) 1303 devt = part->bd_dev; 1304 rcu_read_unlock(); 1305 1306 return devt; 1307 } 1308 1309 dev_t blk_lookup_devt(const char *name, int partno) 1310 { 1311 dev_t devt = MKDEV(0, 0); 1312 struct class_dev_iter iter; 1313 struct device *dev; 1314 1315 class_dev_iter_init(&iter, &block_class, NULL, &disk_type); 1316 while ((dev = class_dev_iter_next(&iter))) { 1317 struct gendisk *disk = dev_to_disk(dev); 1318 1319 if (strcmp(dev_name(dev), name)) 1320 continue; 1321 1322 if (partno < disk->minors) { 1323 /* We need to return the right devno, even 1324 * if the partition doesn't exist yet. 1325 */ 1326 devt = MKDEV(MAJOR(dev->devt), 1327 MINOR(dev->devt) + partno); 1328 } else { 1329 devt = part_devt(disk, partno); 1330 if (devt) 1331 break; 1332 } 1333 } 1334 class_dev_iter_exit(&iter); 1335 return devt; 1336 } 1337 1338 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, 1339 struct lock_class_key *lkclass) 1340 { 1341 struct gendisk *disk; 1342 1343 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); 1344 if (!disk) 1345 return NULL; 1346 1347 if (bioset_init(&disk->bio_split, BIO_POOL_SIZE, 0, 0)) 1348 goto out_free_disk; 1349 1350 disk->bdi = bdi_alloc(node_id); 1351 if (!disk->bdi) 1352 goto out_free_bioset; 1353 1354 /* bdev_alloc() might need the queue, set before the first call */ 1355 disk->queue = q; 1356 1357 disk->part0 = bdev_alloc(disk, 0); 1358 if (!disk->part0) 1359 goto out_free_bdi; 1360 1361 disk->node_id = node_id; 1362 mutex_init(&disk->open_mutex); 1363 xa_init(&disk->part_tbl); 1364 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL)) 1365 goto out_destroy_part_tbl; 1366 1367 if (blkcg_init_queue(q)) 1368 goto out_erase_part0; 1369 1370 rand_initialize_disk(disk); 1371 disk_to_dev(disk)->class = &block_class; 1372 disk_to_dev(disk)->type = &disk_type; 1373 device_initialize(disk_to_dev(disk)); 1374 inc_diskseq(disk); 1375 q->disk = disk; 1376 lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0); 1377 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED 1378 INIT_LIST_HEAD(&disk->slave_bdevs); 1379 #endif 1380 return disk; 1381 1382 out_erase_part0: 1383 xa_erase(&disk->part_tbl, 0); 1384 out_destroy_part_tbl: 1385 xa_destroy(&disk->part_tbl); 1386 disk->part0->bd_disk = NULL; 1387 iput(disk->part0->bd_inode); 1388 out_free_bdi: 1389 bdi_put(disk->bdi); 1390 out_free_bioset: 1391 bioset_exit(&disk->bio_split); 1392 out_free_disk: 1393 kfree(disk); 1394 return NULL; 1395 } 1396 1397 struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass) 1398 { 1399 struct request_queue *q; 1400 struct gendisk *disk; 1401 1402 q = blk_alloc_queue(node, false); 1403 if (!q) 1404 return NULL; 1405 1406 disk = __alloc_disk_node(q, node, lkclass); 1407 if (!disk) { 1408 blk_put_queue(q); 1409 return NULL; 1410 } 1411 set_bit(GD_OWNS_QUEUE, &disk->state); 1412 return disk; 1413 } 1414 EXPORT_SYMBOL(__blk_alloc_disk); 1415 1416 /** 1417 * put_disk - decrements the gendisk refcount 1418 * @disk: the struct gendisk to decrement the refcount for 1419 * 1420 * This decrements the refcount for the struct gendisk. When this reaches 0 1421 * we'll have disk_release() called. 1422 * 1423 * Note: for blk-mq disk put_disk must be called before freeing the tag_set 1424 * when handling probe errors (that is before add_disk() is called). 1425 * 1426 * Context: Any context, but the last reference must not be dropped from 1427 * atomic context. 1428 */ 1429 void put_disk(struct gendisk *disk) 1430 { 1431 if (disk) 1432 put_device(disk_to_dev(disk)); 1433 } 1434 EXPORT_SYMBOL(put_disk); 1435 1436 static void set_disk_ro_uevent(struct gendisk *gd, int ro) 1437 { 1438 char event[] = "DISK_RO=1"; 1439 char *envp[] = { event, NULL }; 1440 1441 if (!ro) 1442 event[8] = '0'; 1443 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); 1444 } 1445 1446 /** 1447 * set_disk_ro - set a gendisk read-only 1448 * @disk: gendisk to operate on 1449 * @read_only: %true to set the disk read-only, %false set the disk read/write 1450 * 1451 * This function is used to indicate whether a given disk device should have its 1452 * read-only flag set. set_disk_ro() is typically used by device drivers to 1453 * indicate whether the underlying physical device is write-protected. 1454 */ 1455 void set_disk_ro(struct gendisk *disk, bool read_only) 1456 { 1457 if (read_only) { 1458 if (test_and_set_bit(GD_READ_ONLY, &disk->state)) 1459 return; 1460 } else { 1461 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state)) 1462 return; 1463 } 1464 set_disk_ro_uevent(disk, read_only); 1465 } 1466 EXPORT_SYMBOL(set_disk_ro); 1467 1468 void inc_diskseq(struct gendisk *disk) 1469 { 1470 disk->diskseq = atomic64_inc_return(&diskseq); 1471 } 1472