1 /* 2 * gendisk handling 3 */ 4 5 #include <linux/config.h> 6 #include <linux/module.h> 7 #include <linux/fs.h> 8 #include <linux/genhd.h> 9 #include <linux/kernel.h> 10 #include <linux/blkdev.h> 11 #include <linux/init.h> 12 #include <linux/spinlock.h> 13 #include <linux/seq_file.h> 14 #include <linux/slab.h> 15 #include <linux/kmod.h> 16 #include <linux/kobj_map.h> 17 #include <linux/buffer_head.h> 18 19 #define MAX_PROBE_HASH 255 /* random */ 20 21 static struct subsystem block_subsys; 22 23 static DECLARE_MUTEX(block_subsys_sem); 24 25 /* 26 * Can be deleted altogether. Later. 27 * 28 */ 29 static struct blk_major_name { 30 struct blk_major_name *next; 31 int major; 32 char name[16]; 33 } *major_names[MAX_PROBE_HASH]; 34 35 /* index in the above - for now: assume no multimajor ranges */ 36 static inline int major_to_index(int major) 37 { 38 return major % MAX_PROBE_HASH; 39 } 40 41 #ifdef CONFIG_PROC_FS 42 /* get block device names in somewhat random order */ 43 int get_blkdev_list(char *p, int used) 44 { 45 struct blk_major_name *n; 46 int i, len; 47 48 len = snprintf(p, (PAGE_SIZE-used), "\nBlock devices:\n"); 49 50 down(&block_subsys_sem); 51 for (i = 0; i < ARRAY_SIZE(major_names); i++) { 52 for (n = major_names[i]; n; n = n->next) { 53 /* 54 * If the curent string plus the 5 extra characters 55 * in the line would run us off the page, then we're done 56 */ 57 if ((len + used + strlen(n->name) + 5) >= PAGE_SIZE) 58 goto page_full; 59 len += sprintf(p+len, "%3d %s\n", 60 n->major, n->name); 61 } 62 } 63 page_full: 64 up(&block_subsys_sem); 65 66 return len; 67 } 68 #endif 69 70 int register_blkdev(unsigned int major, const char *name) 71 { 72 struct blk_major_name **n, *p; 73 int index, ret = 0; 74 75 down(&block_subsys_sem); 76 77 /* temporary */ 78 if (major == 0) { 79 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { 80 if (major_names[index] == NULL) 81 break; 82 } 83 84 if (index == 0) { 85 printk("register_blkdev: failed to get major for %s\n", 86 name); 87 ret = -EBUSY; 88 goto out; 89 } 90 major = index; 91 ret = major; 92 } 93 94 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); 95 if (p == NULL) { 96 ret = -ENOMEM; 97 goto out; 98 } 99 100 p->major = major; 101 strlcpy(p->name, name, sizeof(p->name)); 102 p->next = NULL; 103 index = major_to_index(major); 104 105 for (n = &major_names[index]; *n; n = &(*n)->next) { 106 if ((*n)->major == major) 107 break; 108 } 109 if (!*n) 110 *n = p; 111 else 112 ret = -EBUSY; 113 114 if (ret < 0) { 115 printk("register_blkdev: cannot get major %d for %s\n", 116 major, name); 117 kfree(p); 118 } 119 out: 120 up(&block_subsys_sem); 121 return ret; 122 } 123 124 EXPORT_SYMBOL(register_blkdev); 125 126 /* todo: make void - error printk here */ 127 int unregister_blkdev(unsigned int major, const char *name) 128 { 129 struct blk_major_name **n; 130 struct blk_major_name *p = NULL; 131 int index = major_to_index(major); 132 int ret = 0; 133 134 down(&block_subsys_sem); 135 for (n = &major_names[index]; *n; n = &(*n)->next) 136 if ((*n)->major == major) 137 break; 138 if (!*n || strcmp((*n)->name, name)) 139 ret = -EINVAL; 140 else { 141 p = *n; 142 *n = p->next; 143 } 144 up(&block_subsys_sem); 145 kfree(p); 146 147 return ret; 148 } 149 150 EXPORT_SYMBOL(unregister_blkdev); 151 152 static struct kobj_map *bdev_map; 153 154 /* 155 * Register device numbers dev..(dev+range-1) 156 * range must be nonzero 157 * The hash chain is sorted on range, so that subranges can override. 158 */ 159 void blk_register_region(dev_t dev, unsigned long range, struct module *module, 160 struct kobject *(*probe)(dev_t, int *, void *), 161 int (*lock)(dev_t, void *), void *data) 162 { 163 kobj_map(bdev_map, dev, range, module, probe, lock, data); 164 } 165 166 EXPORT_SYMBOL(blk_register_region); 167 168 void blk_unregister_region(dev_t dev, unsigned long range) 169 { 170 kobj_unmap(bdev_map, dev, range); 171 } 172 173 EXPORT_SYMBOL(blk_unregister_region); 174 175 static struct kobject *exact_match(dev_t dev, int *part, void *data) 176 { 177 struct gendisk *p = data; 178 return &p->kobj; 179 } 180 181 static int exact_lock(dev_t dev, void *data) 182 { 183 struct gendisk *p = data; 184 185 if (!get_disk(p)) 186 return -1; 187 return 0; 188 } 189 190 /** 191 * add_disk - add partitioning information to kernel list 192 * @disk: per-device partitioning information 193 * 194 * This function registers the partitioning information in @disk 195 * with the kernel. 196 */ 197 void add_disk(struct gendisk *disk) 198 { 199 disk->flags |= GENHD_FL_UP; 200 blk_register_region(MKDEV(disk->major, disk->first_minor), 201 disk->minors, NULL, exact_match, exact_lock, disk); 202 register_disk(disk); 203 blk_register_queue(disk); 204 } 205 206 EXPORT_SYMBOL(add_disk); 207 EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */ 208 209 void unlink_gendisk(struct gendisk *disk) 210 { 211 blk_unregister_queue(disk); 212 blk_unregister_region(MKDEV(disk->major, disk->first_minor), 213 disk->minors); 214 } 215 216 #define to_disk(obj) container_of(obj,struct gendisk,kobj) 217 218 /** 219 * get_gendisk - get partitioning information for a given device 220 * @dev: device to get partitioning information for 221 * 222 * This function gets the structure containing partitioning 223 * information for the given device @dev. 224 */ 225 struct gendisk *get_gendisk(dev_t dev, int *part) 226 { 227 struct kobject *kobj = kobj_lookup(bdev_map, dev, part); 228 return kobj ? to_disk(kobj) : NULL; 229 } 230 231 #ifdef CONFIG_PROC_FS 232 /* iterator */ 233 static void *part_start(struct seq_file *part, loff_t *pos) 234 { 235 struct list_head *p; 236 loff_t l = *pos; 237 238 down(&block_subsys_sem); 239 list_for_each(p, &block_subsys.kset.list) 240 if (!l--) 241 return list_entry(p, struct gendisk, kobj.entry); 242 return NULL; 243 } 244 245 static void *part_next(struct seq_file *part, void *v, loff_t *pos) 246 { 247 struct list_head *p = ((struct gendisk *)v)->kobj.entry.next; 248 ++*pos; 249 return p==&block_subsys.kset.list ? NULL : 250 list_entry(p, struct gendisk, kobj.entry); 251 } 252 253 static void part_stop(struct seq_file *part, void *v) 254 { 255 up(&block_subsys_sem); 256 } 257 258 static int show_partition(struct seq_file *part, void *v) 259 { 260 struct gendisk *sgp = v; 261 int n; 262 char buf[BDEVNAME_SIZE]; 263 264 if (&sgp->kobj.entry == block_subsys.kset.list.next) 265 seq_puts(part, "major minor #blocks name\n\n"); 266 267 /* Don't show non-partitionable removeable devices or empty devices */ 268 if (!get_capacity(sgp) || 269 (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE))) 270 return 0; 271 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) 272 return 0; 273 274 /* show the full disk and all non-0 size partitions of it */ 275 seq_printf(part, "%4d %4d %10llu %s\n", 276 sgp->major, sgp->first_minor, 277 (unsigned long long)get_capacity(sgp) >> 1, 278 disk_name(sgp, 0, buf)); 279 for (n = 0; n < sgp->minors - 1; n++) { 280 if (!sgp->part[n]) 281 continue; 282 if (sgp->part[n]->nr_sects == 0) 283 continue; 284 seq_printf(part, "%4d %4d %10llu %s\n", 285 sgp->major, n + 1 + sgp->first_minor, 286 (unsigned long long)sgp->part[n]->nr_sects >> 1 , 287 disk_name(sgp, n + 1, buf)); 288 } 289 290 return 0; 291 } 292 293 struct seq_operations partitions_op = { 294 .start =part_start, 295 .next = part_next, 296 .stop = part_stop, 297 .show = show_partition 298 }; 299 #endif 300 301 302 extern int blk_dev_init(void); 303 304 static struct kobject *base_probe(dev_t dev, int *part, void *data) 305 { 306 if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0) 307 /* Make old-style 2.4 aliases work */ 308 request_module("block-major-%d", MAJOR(dev)); 309 return NULL; 310 } 311 312 static int __init genhd_device_init(void) 313 { 314 bdev_map = kobj_map_init(base_probe, &block_subsys_sem); 315 blk_dev_init(); 316 subsystem_register(&block_subsys); 317 return 0; 318 } 319 320 subsys_initcall(genhd_device_init); 321 322 323 324 /* 325 * kobject & sysfs bindings for block devices 326 */ 327 static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr, 328 char *page) 329 { 330 struct gendisk *disk = to_disk(kobj); 331 struct disk_attribute *disk_attr = 332 container_of(attr,struct disk_attribute,attr); 333 ssize_t ret = -EIO; 334 335 if (disk_attr->show) 336 ret = disk_attr->show(disk,page); 337 return ret; 338 } 339 340 static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr, 341 const char *page, size_t count) 342 { 343 struct gendisk *disk = to_disk(kobj); 344 struct disk_attribute *disk_attr = 345 container_of(attr,struct disk_attribute,attr); 346 ssize_t ret = 0; 347 348 if (disk_attr->store) 349 ret = disk_attr->store(disk, page, count); 350 return ret; 351 } 352 353 static struct sysfs_ops disk_sysfs_ops = { 354 .show = &disk_attr_show, 355 .store = &disk_attr_store, 356 }; 357 358 static ssize_t disk_uevent_store(struct gendisk * disk, 359 const char *buf, size_t count) 360 { 361 kobject_uevent(&disk->kobj, KOBJ_ADD); 362 return count; 363 } 364 static ssize_t disk_dev_read(struct gendisk * disk, char *page) 365 { 366 dev_t base = MKDEV(disk->major, disk->first_minor); 367 return print_dev_t(page, base); 368 } 369 static ssize_t disk_range_read(struct gendisk * disk, char *page) 370 { 371 return sprintf(page, "%d\n", disk->minors); 372 } 373 static ssize_t disk_removable_read(struct gendisk * disk, char *page) 374 { 375 return sprintf(page, "%d\n", 376 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); 377 378 } 379 static ssize_t disk_size_read(struct gendisk * disk, char *page) 380 { 381 return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk)); 382 } 383 384 static ssize_t disk_stats_read(struct gendisk * disk, char *page) 385 { 386 preempt_disable(); 387 disk_round_stats(disk); 388 preempt_enable(); 389 return sprintf(page, 390 "%8u %8u %8llu %8u " 391 "%8u %8u %8llu %8u " 392 "%8u %8u %8u" 393 "\n", 394 disk_stat_read(disk, ios[READ]), 395 disk_stat_read(disk, merges[READ]), 396 (unsigned long long)disk_stat_read(disk, sectors[READ]), 397 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])), 398 disk_stat_read(disk, ios[WRITE]), 399 disk_stat_read(disk, merges[WRITE]), 400 (unsigned long long)disk_stat_read(disk, sectors[WRITE]), 401 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])), 402 disk->in_flight, 403 jiffies_to_msecs(disk_stat_read(disk, io_ticks)), 404 jiffies_to_msecs(disk_stat_read(disk, time_in_queue))); 405 } 406 static struct disk_attribute disk_attr_uevent = { 407 .attr = {.name = "uevent", .mode = S_IWUSR }, 408 .store = disk_uevent_store 409 }; 410 static struct disk_attribute disk_attr_dev = { 411 .attr = {.name = "dev", .mode = S_IRUGO }, 412 .show = disk_dev_read 413 }; 414 static struct disk_attribute disk_attr_range = { 415 .attr = {.name = "range", .mode = S_IRUGO }, 416 .show = disk_range_read 417 }; 418 static struct disk_attribute disk_attr_removable = { 419 .attr = {.name = "removable", .mode = S_IRUGO }, 420 .show = disk_removable_read 421 }; 422 static struct disk_attribute disk_attr_size = { 423 .attr = {.name = "size", .mode = S_IRUGO }, 424 .show = disk_size_read 425 }; 426 static struct disk_attribute disk_attr_stat = { 427 .attr = {.name = "stat", .mode = S_IRUGO }, 428 .show = disk_stats_read 429 }; 430 431 static struct attribute * default_attrs[] = { 432 &disk_attr_uevent.attr, 433 &disk_attr_dev.attr, 434 &disk_attr_range.attr, 435 &disk_attr_removable.attr, 436 &disk_attr_size.attr, 437 &disk_attr_stat.attr, 438 NULL, 439 }; 440 441 static void disk_release(struct kobject * kobj) 442 { 443 struct gendisk *disk = to_disk(kobj); 444 kfree(disk->random); 445 kfree(disk->part); 446 free_disk_stats(disk); 447 kfree(disk); 448 } 449 450 static struct kobj_type ktype_block = { 451 .release = disk_release, 452 .sysfs_ops = &disk_sysfs_ops, 453 .default_attrs = default_attrs, 454 }; 455 456 extern struct kobj_type ktype_part; 457 458 static int block_uevent_filter(struct kset *kset, struct kobject *kobj) 459 { 460 struct kobj_type *ktype = get_ktype(kobj); 461 462 return ((ktype == &ktype_block) || (ktype == &ktype_part)); 463 } 464 465 static int block_uevent(struct kset *kset, struct kobject *kobj, char **envp, 466 int num_envp, char *buffer, int buffer_size) 467 { 468 struct kobj_type *ktype = get_ktype(kobj); 469 struct device *physdev; 470 struct gendisk *disk; 471 struct hd_struct *part; 472 int length = 0; 473 int i = 0; 474 475 if (ktype == &ktype_block) { 476 disk = container_of(kobj, struct gendisk, kobj); 477 add_uevent_var(envp, num_envp, &i, buffer, buffer_size, 478 &length, "MINOR=%u", disk->first_minor); 479 } else if (ktype == &ktype_part) { 480 disk = container_of(kobj->parent, struct gendisk, kobj); 481 part = container_of(kobj, struct hd_struct, kobj); 482 add_uevent_var(envp, num_envp, &i, buffer, buffer_size, 483 &length, "MINOR=%u", 484 disk->first_minor + part->partno); 485 } else 486 return 0; 487 488 add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, 489 "MAJOR=%u", disk->major); 490 491 /* add physical device, backing this device */ 492 physdev = disk->driverfs_dev; 493 if (physdev) { 494 char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL); 495 496 add_uevent_var(envp, num_envp, &i, buffer, buffer_size, 497 &length, "PHYSDEVPATH=%s", path); 498 kfree(path); 499 500 if (physdev->bus) 501 add_uevent_var(envp, num_envp, &i, 502 buffer, buffer_size, &length, 503 "PHYSDEVBUS=%s", 504 physdev->bus->name); 505 506 if (physdev->driver) 507 add_uevent_var(envp, num_envp, &i, 508 buffer, buffer_size, &length, 509 "PHYSDEVDRIVER=%s", 510 physdev->driver->name); 511 } 512 513 /* terminate, set to next free slot, shrink available space */ 514 envp[i] = NULL; 515 envp = &envp[i]; 516 num_envp -= i; 517 buffer = &buffer[length]; 518 buffer_size -= length; 519 520 return 0; 521 } 522 523 static struct kset_uevent_ops block_uevent_ops = { 524 .filter = block_uevent_filter, 525 .uevent = block_uevent, 526 }; 527 528 /* declare block_subsys. */ 529 static decl_subsys(block, &ktype_block, &block_uevent_ops); 530 531 532 /* 533 * aggregate disk stat collector. Uses the same stats that the sysfs 534 * entries do, above, but makes them available through one seq_file. 535 * Watching a few disks may be efficient through sysfs, but watching 536 * all of them will be more efficient through this interface. 537 * 538 * The output looks suspiciously like /proc/partitions with a bunch of 539 * extra fields. 540 */ 541 542 /* iterator */ 543 static void *diskstats_start(struct seq_file *part, loff_t *pos) 544 { 545 loff_t k = *pos; 546 struct list_head *p; 547 548 down(&block_subsys_sem); 549 list_for_each(p, &block_subsys.kset.list) 550 if (!k--) 551 return list_entry(p, struct gendisk, kobj.entry); 552 return NULL; 553 } 554 555 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos) 556 { 557 struct list_head *p = ((struct gendisk *)v)->kobj.entry.next; 558 ++*pos; 559 return p==&block_subsys.kset.list ? NULL : 560 list_entry(p, struct gendisk, kobj.entry); 561 } 562 563 static void diskstats_stop(struct seq_file *part, void *v) 564 { 565 up(&block_subsys_sem); 566 } 567 568 static int diskstats_show(struct seq_file *s, void *v) 569 { 570 struct gendisk *gp = v; 571 char buf[BDEVNAME_SIZE]; 572 int n = 0; 573 574 /* 575 if (&sgp->kobj.entry == block_subsys.kset.list.next) 576 seq_puts(s, "major minor name" 577 " rio rmerge rsect ruse wio wmerge " 578 "wsect wuse running use aveq" 579 "\n\n"); 580 */ 581 582 preempt_disable(); 583 disk_round_stats(gp); 584 preempt_enable(); 585 seq_printf(s, "%4d %4d %s %u %u %llu %u %u %u %llu %u %u %u %u\n", 586 gp->major, n + gp->first_minor, disk_name(gp, n, buf), 587 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]), 588 (unsigned long long)disk_stat_read(gp, sectors[0]), 589 jiffies_to_msecs(disk_stat_read(gp, ticks[0])), 590 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]), 591 (unsigned long long)disk_stat_read(gp, sectors[1]), 592 jiffies_to_msecs(disk_stat_read(gp, ticks[1])), 593 gp->in_flight, 594 jiffies_to_msecs(disk_stat_read(gp, io_ticks)), 595 jiffies_to_msecs(disk_stat_read(gp, time_in_queue))); 596 597 /* now show all non-0 size partitions of it */ 598 for (n = 0; n < gp->minors - 1; n++) { 599 struct hd_struct *hd = gp->part[n]; 600 601 if (hd && hd->nr_sects) 602 seq_printf(s, "%4d %4d %s %u %u %u %u\n", 603 gp->major, n + gp->first_minor + 1, 604 disk_name(gp, n + 1, buf), 605 hd->ios[0], hd->sectors[0], 606 hd->ios[1], hd->sectors[1]); 607 } 608 609 return 0; 610 } 611 612 struct seq_operations diskstats_op = { 613 .start = diskstats_start, 614 .next = diskstats_next, 615 .stop = diskstats_stop, 616 .show = diskstats_show 617 }; 618 619 struct gendisk *alloc_disk(int minors) 620 { 621 return alloc_disk_node(minors, -1); 622 } 623 624 struct gendisk *alloc_disk_node(int minors, int node_id) 625 { 626 struct gendisk *disk; 627 628 disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); 629 if (disk) { 630 memset(disk, 0, sizeof(struct gendisk)); 631 if (!init_disk_stats(disk)) { 632 kfree(disk); 633 return NULL; 634 } 635 if (minors > 1) { 636 int size = (minors - 1) * sizeof(struct hd_struct *); 637 disk->part = kmalloc_node(size, GFP_KERNEL, node_id); 638 if (!disk->part) { 639 kfree(disk); 640 return NULL; 641 } 642 memset(disk->part, 0, size); 643 } 644 disk->minors = minors; 645 kobj_set_kset_s(disk,block_subsys); 646 kobject_init(&disk->kobj); 647 rand_initialize_disk(disk); 648 } 649 return disk; 650 } 651 652 EXPORT_SYMBOL(alloc_disk); 653 EXPORT_SYMBOL(alloc_disk_node); 654 655 struct kobject *get_disk(struct gendisk *disk) 656 { 657 struct module *owner; 658 struct kobject *kobj; 659 660 if (!disk->fops) 661 return NULL; 662 owner = disk->fops->owner; 663 if (owner && !try_module_get(owner)) 664 return NULL; 665 kobj = kobject_get(&disk->kobj); 666 if (kobj == NULL) { 667 module_put(owner); 668 return NULL; 669 } 670 return kobj; 671 672 } 673 674 EXPORT_SYMBOL(get_disk); 675 676 void put_disk(struct gendisk *disk) 677 { 678 if (disk) 679 kobject_put(&disk->kobj); 680 } 681 682 EXPORT_SYMBOL(put_disk); 683 684 void set_device_ro(struct block_device *bdev, int flag) 685 { 686 if (bdev->bd_contains != bdev) 687 bdev->bd_part->policy = flag; 688 else 689 bdev->bd_disk->policy = flag; 690 } 691 692 EXPORT_SYMBOL(set_device_ro); 693 694 void set_disk_ro(struct gendisk *disk, int flag) 695 { 696 int i; 697 disk->policy = flag; 698 for (i = 0; i < disk->minors - 1; i++) 699 if (disk->part[i]) disk->part[i]->policy = flag; 700 } 701 702 EXPORT_SYMBOL(set_disk_ro); 703 704 int bdev_read_only(struct block_device *bdev) 705 { 706 if (!bdev) 707 return 0; 708 else if (bdev->bd_contains != bdev) 709 return bdev->bd_part->policy; 710 else 711 return bdev->bd_disk->policy; 712 } 713 714 EXPORT_SYMBOL(bdev_read_only); 715 716 int invalidate_partition(struct gendisk *disk, int index) 717 { 718 int res = 0; 719 struct block_device *bdev = bdget_disk(disk, index); 720 if (bdev) { 721 fsync_bdev(bdev); 722 res = __invalidate_device(bdev); 723 bdput(bdev); 724 } 725 return res; 726 } 727 728 EXPORT_SYMBOL(invalidate_partition); 729