1 #include <linux/module.h> 2 #include <linux/sched.h> 3 #include <linux/ctype.h> 4 #include <linux/fd.h> 5 #include <linux/tty.h> 6 #include <linux/suspend.h> 7 #include <linux/root_dev.h> 8 #include <linux/security.h> 9 #include <linux/delay.h> 10 #include <linux/genhd.h> 11 #include <linux/mount.h> 12 #include <linux/device.h> 13 #include <linux/init.h> 14 #include <linux/fs.h> 15 #include <linux/initrd.h> 16 #include <linux/async.h> 17 #include <linux/fs_struct.h> 18 #include <linux/slab.h> 19 #include <linux/ramfs.h> 20 #include <linux/shmem_fs.h> 21 22 #include <linux/nfs_fs.h> 23 #include <linux/nfs_fs_sb.h> 24 #include <linux/nfs_mount.h> 25 26 #include "do_mounts.h" 27 28 int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */ 29 30 int root_mountflags = MS_RDONLY | MS_SILENT; 31 static char * __initdata root_device_name; 32 static char __initdata saved_root_name[64]; 33 static int root_wait; 34 35 dev_t ROOT_DEV; 36 37 static int __init load_ramdisk(char *str) 38 { 39 rd_doload = simple_strtol(str,NULL,0) & 3; 40 return 1; 41 } 42 __setup("load_ramdisk=", load_ramdisk); 43 44 static int __init readonly(char *str) 45 { 46 if (*str) 47 return 0; 48 root_mountflags |= MS_RDONLY; 49 return 1; 50 } 51 52 static int __init readwrite(char *str) 53 { 54 if (*str) 55 return 0; 56 root_mountflags &= ~MS_RDONLY; 57 return 1; 58 } 59 60 __setup("ro", readonly); 61 __setup("rw", readwrite); 62 63 #ifdef CONFIG_BLOCK 64 struct uuidcmp { 65 const char *uuid; 66 int len; 67 }; 68 69 /** 70 * match_dev_by_uuid - callback for finding a partition using its uuid 71 * @dev: device passed in by the caller 72 * @data: opaque pointer to the desired struct uuidcmp to match 73 * 74 * Returns 1 if the device matches, and 0 otherwise. 75 */ 76 static int match_dev_by_uuid(struct device *dev, const void *data) 77 { 78 const struct uuidcmp *cmp = data; 79 struct hd_struct *part = dev_to_part(dev); 80 81 if (!part->info) 82 goto no_match; 83 84 if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len)) 85 goto no_match; 86 87 return 1; 88 no_match: 89 return 0; 90 } 91 92 93 /** 94 * devt_from_partuuid - looks up the dev_t of a partition by its UUID 95 * @uuid_str: char array containing ascii UUID 96 * 97 * The function will return the first partition which contains a matching 98 * UUID value in its partition_meta_info struct. This does not search 99 * by filesystem UUIDs. 100 * 101 * If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be 102 * extracted and used as an offset from the partition identified by the UUID. 103 * 104 * Returns the matching dev_t on success or 0 on failure. 105 */ 106 static dev_t devt_from_partuuid(const char *uuid_str) 107 { 108 dev_t res = 0; 109 struct uuidcmp cmp; 110 struct device *dev = NULL; 111 struct gendisk *disk; 112 struct hd_struct *part; 113 int offset = 0; 114 bool clear_root_wait = false; 115 char *slash; 116 117 cmp.uuid = uuid_str; 118 119 slash = strchr(uuid_str, '/'); 120 /* Check for optional partition number offset attributes. */ 121 if (slash) { 122 char c = 0; 123 /* Explicitly fail on poor PARTUUID syntax. */ 124 if (sscanf(slash + 1, 125 "PARTNROFF=%d%c", &offset, &c) != 1) { 126 clear_root_wait = true; 127 goto done; 128 } 129 cmp.len = slash - uuid_str; 130 } else { 131 cmp.len = strlen(uuid_str); 132 } 133 134 if (!cmp.len) { 135 clear_root_wait = true; 136 goto done; 137 } 138 139 dev = class_find_device(&block_class, NULL, &cmp, 140 &match_dev_by_uuid); 141 if (!dev) 142 goto done; 143 144 res = dev->devt; 145 146 /* Attempt to find the partition by offset. */ 147 if (!offset) 148 goto no_offset; 149 150 res = 0; 151 disk = part_to_disk(dev_to_part(dev)); 152 part = disk_get_part(disk, dev_to_part(dev)->partno + offset); 153 if (part) { 154 res = part_devt(part); 155 put_device(part_to_dev(part)); 156 } 157 158 no_offset: 159 put_device(dev); 160 done: 161 if (clear_root_wait) { 162 pr_err("VFS: PARTUUID= is invalid.\n" 163 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n"); 164 if (root_wait) 165 pr_err("Disabling rootwait; root= is invalid.\n"); 166 root_wait = 0; 167 } 168 return res; 169 } 170 171 /** 172 * match_dev_by_label - callback for finding a partition using its label 173 * @dev: device passed in by the caller 174 * @data: opaque pointer to the label to match 175 * 176 * Returns 1 if the device matches, and 0 otherwise. 177 */ 178 static int match_dev_by_label(struct device *dev, const void *data) 179 { 180 const char *label = data; 181 struct hd_struct *part = dev_to_part(dev); 182 183 if (part->info && !strcmp(label, part->info->volname)) 184 return 1; 185 186 return 0; 187 } 188 #endif 189 190 /* 191 * Convert a name into device number. We accept the following variants: 192 * 193 * 1) <hex_major><hex_minor> device number in hexadecimal represents itself 194 * no leading 0x, for example b302. 195 * 2) /dev/nfs represents Root_NFS (0xff) 196 * 3) /dev/<disk_name> represents the device number of disk 197 * 4) /dev/<disk_name><decimal> represents the device number 198 * of partition - device number of disk plus the partition number 199 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is 200 * used when disk name of partitioned disk ends on a digit. 201 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the 202 * unique id of a partition if the partition table provides it. 203 * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS 204 * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- 205 * filled hex representation of the 32-bit "NT disk signature", and PP 206 * is a zero-filled hex representation of the 1-based partition number. 207 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to 208 * a partition with a known unique id. 209 * 8) <major>:<minor> major and minor number of the device separated by 210 * a colon. 211 * 9) PARTLABEL=<name> with name being the GPT partition label. 212 * MSDOS partitions do not support labels! 213 * 214 * If name doesn't have fall into the categories above, we return (0,0). 215 * block_class is used to check if something is a disk name. If the disk 216 * name contains slashes, the device name has them replaced with 217 * bangs. 218 */ 219 220 dev_t name_to_dev_t(const char *name) 221 { 222 char s[32]; 223 char *p; 224 dev_t res = 0; 225 int part; 226 227 #ifdef CONFIG_BLOCK 228 if (strncmp(name, "PARTUUID=", 9) == 0) { 229 name += 9; 230 res = devt_from_partuuid(name); 231 if (!res) 232 goto fail; 233 goto done; 234 } else if (strncmp(name, "PARTLABEL=", 10) == 0) { 235 struct device *dev; 236 237 dev = class_find_device(&block_class, NULL, name + 10, 238 &match_dev_by_label); 239 if (!dev) 240 goto fail; 241 242 res = dev->devt; 243 put_device(dev); 244 goto done; 245 } 246 #endif 247 248 if (strncmp(name, "/dev/", 5) != 0) { 249 unsigned maj, min, offset; 250 char dummy; 251 252 if ((sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) || 253 (sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3)) { 254 res = MKDEV(maj, min); 255 if (maj != MAJOR(res) || min != MINOR(res)) 256 goto fail; 257 } else { 258 res = new_decode_dev(simple_strtoul(name, &p, 16)); 259 if (*p) 260 goto fail; 261 } 262 goto done; 263 } 264 265 name += 5; 266 res = Root_NFS; 267 if (strcmp(name, "nfs") == 0) 268 goto done; 269 res = Root_RAM0; 270 if (strcmp(name, "ram") == 0) 271 goto done; 272 273 if (strlen(name) > 31) 274 goto fail; 275 strcpy(s, name); 276 for (p = s; *p; p++) 277 if (*p == '/') 278 *p = '!'; 279 res = blk_lookup_devt(s, 0); 280 if (res) 281 goto done; 282 283 /* 284 * try non-existent, but valid partition, which may only exist 285 * after revalidating the disk, like partitioned md devices 286 */ 287 while (p > s && isdigit(p[-1])) 288 p--; 289 if (p == s || !*p || *p == '0') 290 goto fail; 291 292 /* try disk name without <part number> */ 293 part = simple_strtoul(p, NULL, 10); 294 *p = '\0'; 295 res = blk_lookup_devt(s, part); 296 if (res) 297 goto done; 298 299 /* try disk name without p<part number> */ 300 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') 301 goto fail; 302 p[-1] = '\0'; 303 res = blk_lookup_devt(s, part); 304 if (res) 305 goto done; 306 307 fail: 308 return 0; 309 done: 310 return res; 311 } 312 EXPORT_SYMBOL_GPL(name_to_dev_t); 313 314 static int __init root_dev_setup(char *line) 315 { 316 strlcpy(saved_root_name, line, sizeof(saved_root_name)); 317 return 1; 318 } 319 320 __setup("root=", root_dev_setup); 321 322 static int __init rootwait_setup(char *str) 323 { 324 if (*str) 325 return 0; 326 root_wait = 1; 327 return 1; 328 } 329 330 __setup("rootwait", rootwait_setup); 331 332 static char * __initdata root_mount_data; 333 static int __init root_data_setup(char *str) 334 { 335 root_mount_data = str; 336 return 1; 337 } 338 339 static char * __initdata root_fs_names; 340 static int __init fs_names_setup(char *str) 341 { 342 root_fs_names = str; 343 return 1; 344 } 345 346 static unsigned int __initdata root_delay; 347 static int __init root_delay_setup(char *str) 348 { 349 root_delay = simple_strtoul(str, NULL, 0); 350 return 1; 351 } 352 353 __setup("rootflags=", root_data_setup); 354 __setup("rootfstype=", fs_names_setup); 355 __setup("rootdelay=", root_delay_setup); 356 357 static void __init get_fs_names(char *page) 358 { 359 char *s = page; 360 361 if (root_fs_names) { 362 strcpy(page, root_fs_names); 363 while (*s++) { 364 if (s[-1] == ',') 365 s[-1] = '\0'; 366 } 367 } else { 368 int len = get_filesystem_list(page); 369 char *p, *next; 370 371 page[len] = '\0'; 372 for (p = page-1; p; p = next) { 373 next = strchr(++p, '\n'); 374 if (*p++ != '\t') 375 continue; 376 while ((*s++ = *p++) != '\n') 377 ; 378 s[-1] = '\0'; 379 } 380 } 381 *s = '\0'; 382 } 383 384 static int __init do_mount_root(char *name, char *fs, int flags, void *data) 385 { 386 struct super_block *s; 387 int err = ksys_mount(name, "/root", fs, flags, data); 388 if (err) 389 return err; 390 391 ksys_chdir("/root"); 392 s = current->fs->pwd.dentry->d_sb; 393 ROOT_DEV = s->s_dev; 394 printk(KERN_INFO 395 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n", 396 s->s_type->name, 397 sb_rdonly(s) ? " readonly" : "", 398 MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 399 return 0; 400 } 401 402 void __init mount_block_root(char *name, int flags) 403 { 404 struct page *page = alloc_page(GFP_KERNEL); 405 char *fs_names = page_address(page); 406 char *p; 407 #ifdef CONFIG_BLOCK 408 char b[BDEVNAME_SIZE]; 409 #else 410 const char *b = name; 411 #endif 412 413 get_fs_names(fs_names); 414 retry: 415 for (p = fs_names; *p; p += strlen(p)+1) { 416 int err = do_mount_root(name, p, flags, root_mount_data); 417 switch (err) { 418 case 0: 419 goto out; 420 case -EACCES: 421 case -EINVAL: 422 continue; 423 } 424 /* 425 * Allow the user to distinguish between failed sys_open 426 * and bad superblock on root device. 427 * and give them a list of the available devices 428 */ 429 #ifdef CONFIG_BLOCK 430 __bdevname(ROOT_DEV, b); 431 #endif 432 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n", 433 root_device_name, b, err); 434 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); 435 436 printk_all_partitions(); 437 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT 438 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " 439 "explicit textual name for \"root=\" boot option.\n"); 440 #endif 441 panic("VFS: Unable to mount root fs on %s", b); 442 } 443 if (!(flags & SB_RDONLY)) { 444 flags |= SB_RDONLY; 445 goto retry; 446 } 447 448 printk("List of all partitions:\n"); 449 printk_all_partitions(); 450 printk("No filesystem could mount root, tried: "); 451 for (p = fs_names; *p; p += strlen(p)+1) 452 printk(" %s", p); 453 printk("\n"); 454 #ifdef CONFIG_BLOCK 455 __bdevname(ROOT_DEV, b); 456 #endif 457 panic("VFS: Unable to mount root fs on %s", b); 458 out: 459 put_page(page); 460 } 461 462 #ifdef CONFIG_ROOT_NFS 463 464 #define NFSROOT_TIMEOUT_MIN 5 465 #define NFSROOT_TIMEOUT_MAX 30 466 #define NFSROOT_RETRY_MAX 5 467 468 static int __init mount_nfs_root(void) 469 { 470 char *root_dev, *root_data; 471 unsigned int timeout; 472 int try, err; 473 474 err = nfs_root_data(&root_dev, &root_data); 475 if (err != 0) 476 return 0; 477 478 /* 479 * The server or network may not be ready, so try several 480 * times. Stop after a few tries in case the client wants 481 * to fall back to other boot methods. 482 */ 483 timeout = NFSROOT_TIMEOUT_MIN; 484 for (try = 1; ; try++) { 485 err = do_mount_root(root_dev, "nfs", 486 root_mountflags, root_data); 487 if (err == 0) 488 return 1; 489 if (try > NFSROOT_RETRY_MAX) 490 break; 491 492 /* Wait, in case the server refused us immediately */ 493 ssleep(timeout); 494 timeout <<= 1; 495 if (timeout > NFSROOT_TIMEOUT_MAX) 496 timeout = NFSROOT_TIMEOUT_MAX; 497 } 498 return 0; 499 } 500 #endif 501 502 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD) 503 void __init change_floppy(char *fmt, ...) 504 { 505 struct termios termios; 506 char buf[80]; 507 char c; 508 int fd; 509 va_list args; 510 va_start(args, fmt); 511 vsprintf(buf, fmt, args); 512 va_end(args); 513 fd = ksys_open("/dev/root", O_RDWR | O_NDELAY, 0); 514 if (fd >= 0) { 515 ksys_ioctl(fd, FDEJECT, 0); 516 ksys_close(fd); 517 } 518 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); 519 fd = ksys_open("/dev/console", O_RDWR, 0); 520 if (fd >= 0) { 521 ksys_ioctl(fd, TCGETS, (long)&termios); 522 termios.c_lflag &= ~ICANON; 523 ksys_ioctl(fd, TCSETSF, (long)&termios); 524 ksys_read(fd, &c, 1); 525 termios.c_lflag |= ICANON; 526 ksys_ioctl(fd, TCSETSF, (long)&termios); 527 ksys_close(fd); 528 } 529 } 530 #endif 531 532 void __init mount_root(void) 533 { 534 #ifdef CONFIG_ROOT_NFS 535 if (ROOT_DEV == Root_NFS) { 536 if (mount_nfs_root()) 537 return; 538 539 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n"); 540 ROOT_DEV = Root_FD0; 541 } 542 #endif 543 #ifdef CONFIG_BLK_DEV_FD 544 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) { 545 /* rd_doload is 2 for a dual initrd/ramload setup */ 546 if (rd_doload==2) { 547 if (rd_load_disk(1)) { 548 ROOT_DEV = Root_RAM1; 549 root_device_name = NULL; 550 } 551 } else 552 change_floppy("root floppy"); 553 } 554 #endif 555 #ifdef CONFIG_BLOCK 556 { 557 int err = create_dev("/dev/root", ROOT_DEV); 558 559 if (err < 0) 560 pr_emerg("Failed to create /dev/root: %d\n", err); 561 mount_block_root("/dev/root", root_mountflags); 562 } 563 #endif 564 } 565 566 /* 567 * Prepare the namespace - decide what/where to mount, load ramdisks, etc. 568 */ 569 void __init prepare_namespace(void) 570 { 571 int is_floppy; 572 573 if (root_delay) { 574 printk(KERN_INFO "Waiting %d sec before mounting root device...\n", 575 root_delay); 576 ssleep(root_delay); 577 } 578 579 /* 580 * wait for the known devices to complete their probing 581 * 582 * Note: this is a potential source of long boot delays. 583 * For example, it is not atypical to wait 5 seconds here 584 * for the touchpad of a laptop to initialize. 585 */ 586 wait_for_device_probe(); 587 588 md_run_setup(); 589 590 if (saved_root_name[0]) { 591 root_device_name = saved_root_name; 592 if (!strncmp(root_device_name, "mtd", 3) || 593 !strncmp(root_device_name, "ubi", 3)) { 594 mount_block_root(root_device_name, root_mountflags); 595 goto out; 596 } 597 ROOT_DEV = name_to_dev_t(root_device_name); 598 if (strncmp(root_device_name, "/dev/", 5) == 0) 599 root_device_name += 5; 600 } 601 602 if (initrd_load()) 603 goto out; 604 605 /* wait for any asynchronous scanning to complete */ 606 if ((ROOT_DEV == 0) && root_wait) { 607 printk(KERN_INFO "Waiting for root device %s...\n", 608 saved_root_name); 609 while (driver_probe_done() != 0 || 610 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0) 611 msleep(5); 612 async_synchronize_full(); 613 } 614 615 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR; 616 617 if (is_floppy && rd_doload && rd_load_disk(0)) 618 ROOT_DEV = Root_RAM0; 619 620 mount_root(); 621 out: 622 devtmpfs_mount("dev"); 623 ksys_mount(".", "/", NULL, MS_MOVE, NULL); 624 ksys_chroot("."); 625 } 626 627 static bool is_tmpfs; 628 static struct dentry *rootfs_mount(struct file_system_type *fs_type, 629 int flags, const char *dev_name, void *data) 630 { 631 static unsigned long once; 632 void *fill = ramfs_fill_super; 633 634 if (test_and_set_bit(0, &once)) 635 return ERR_PTR(-ENODEV); 636 637 if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs) 638 fill = shmem_fill_super; 639 640 return mount_nodev(fs_type, flags, data, fill); 641 } 642 643 static struct file_system_type rootfs_fs_type = { 644 .name = "rootfs", 645 .mount = rootfs_mount, 646 .kill_sb = kill_litter_super, 647 }; 648 649 int __init init_rootfs(void) 650 { 651 int err = register_filesystem(&rootfs_fs_type); 652 653 if (err) 654 return err; 655 656 if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] && 657 (!root_fs_names || strstr(root_fs_names, "tmpfs"))) { 658 err = shmem_init(); 659 is_tmpfs = true; 660 } else { 661 err = init_ramfs_fs(); 662 } 663 664 if (err) 665 unregister_filesystem(&rootfs_fs_type); 666 667 return err; 668 } 669