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 #endif 171 172 /* 173 * Convert a name into device number. We accept the following variants: 174 * 175 * 1) <hex_major><hex_minor> device number in hexadecimal represents itself 176 * no leading 0x, for example b302. 177 * 2) /dev/nfs represents Root_NFS (0xff) 178 * 3) /dev/<disk_name> represents the device number of disk 179 * 4) /dev/<disk_name><decimal> represents the device number 180 * of partition - device number of disk plus the partition number 181 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is 182 * used when disk name of partitioned disk ends on a digit. 183 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the 184 * unique id of a partition if the partition table provides it. 185 * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS 186 * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- 187 * filled hex representation of the 32-bit "NT disk signature", and PP 188 * is a zero-filled hex representation of the 1-based partition number. 189 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to 190 * a partition with a known unique id. 191 * 8) <major>:<minor> major and minor number of the device separated by 192 * a colon. 193 * 194 * If name doesn't have fall into the categories above, we return (0,0). 195 * block_class is used to check if something is a disk name. If the disk 196 * name contains slashes, the device name has them replaced with 197 * bangs. 198 */ 199 200 dev_t name_to_dev_t(const char *name) 201 { 202 char s[32]; 203 char *p; 204 dev_t res = 0; 205 int part; 206 207 #ifdef CONFIG_BLOCK 208 if (strncmp(name, "PARTUUID=", 9) == 0) { 209 name += 9; 210 res = devt_from_partuuid(name); 211 if (!res) 212 goto fail; 213 goto done; 214 } 215 #endif 216 217 if (strncmp(name, "/dev/", 5) != 0) { 218 unsigned maj, min, offset; 219 char dummy; 220 221 if ((sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) || 222 (sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3)) { 223 res = MKDEV(maj, min); 224 if (maj != MAJOR(res) || min != MINOR(res)) 225 goto fail; 226 } else { 227 res = new_decode_dev(simple_strtoul(name, &p, 16)); 228 if (*p) 229 goto fail; 230 } 231 goto done; 232 } 233 234 name += 5; 235 res = Root_NFS; 236 if (strcmp(name, "nfs") == 0) 237 goto done; 238 res = Root_RAM0; 239 if (strcmp(name, "ram") == 0) 240 goto done; 241 242 if (strlen(name) > 31) 243 goto fail; 244 strcpy(s, name); 245 for (p = s; *p; p++) 246 if (*p == '/') 247 *p = '!'; 248 res = blk_lookup_devt(s, 0); 249 if (res) 250 goto done; 251 252 /* 253 * try non-existent, but valid partition, which may only exist 254 * after revalidating the disk, like partitioned md devices 255 */ 256 while (p > s && isdigit(p[-1])) 257 p--; 258 if (p == s || !*p || *p == '0') 259 goto fail; 260 261 /* try disk name without <part number> */ 262 part = simple_strtoul(p, NULL, 10); 263 *p = '\0'; 264 res = blk_lookup_devt(s, part); 265 if (res) 266 goto done; 267 268 /* try disk name without p<part number> */ 269 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') 270 goto fail; 271 p[-1] = '\0'; 272 res = blk_lookup_devt(s, part); 273 if (res) 274 goto done; 275 276 fail: 277 return 0; 278 done: 279 return res; 280 } 281 EXPORT_SYMBOL_GPL(name_to_dev_t); 282 283 static int __init root_dev_setup(char *line) 284 { 285 strlcpy(saved_root_name, line, sizeof(saved_root_name)); 286 return 1; 287 } 288 289 __setup("root=", root_dev_setup); 290 291 static int __init rootwait_setup(char *str) 292 { 293 if (*str) 294 return 0; 295 root_wait = 1; 296 return 1; 297 } 298 299 __setup("rootwait", rootwait_setup); 300 301 static char * __initdata root_mount_data; 302 static int __init root_data_setup(char *str) 303 { 304 root_mount_data = str; 305 return 1; 306 } 307 308 static char * __initdata root_fs_names; 309 static int __init fs_names_setup(char *str) 310 { 311 root_fs_names = str; 312 return 1; 313 } 314 315 static unsigned int __initdata root_delay; 316 static int __init root_delay_setup(char *str) 317 { 318 root_delay = simple_strtoul(str, NULL, 0); 319 return 1; 320 } 321 322 __setup("rootflags=", root_data_setup); 323 __setup("rootfstype=", fs_names_setup); 324 __setup("rootdelay=", root_delay_setup); 325 326 static void __init get_fs_names(char *page) 327 { 328 char *s = page; 329 330 if (root_fs_names) { 331 strcpy(page, root_fs_names); 332 while (*s++) { 333 if (s[-1] == ',') 334 s[-1] = '\0'; 335 } 336 } else { 337 int len = get_filesystem_list(page); 338 char *p, *next; 339 340 page[len] = '\0'; 341 for (p = page-1; p; p = next) { 342 next = strchr(++p, '\n'); 343 if (*p++ != '\t') 344 continue; 345 while ((*s++ = *p++) != '\n') 346 ; 347 s[-1] = '\0'; 348 } 349 } 350 *s = '\0'; 351 } 352 353 static int __init do_mount_root(char *name, char *fs, int flags, void *data) 354 { 355 struct super_block *s; 356 int err = ksys_mount(name, "/root", fs, flags, data); 357 if (err) 358 return err; 359 360 ksys_chdir("/root"); 361 s = current->fs->pwd.dentry->d_sb; 362 ROOT_DEV = s->s_dev; 363 printk(KERN_INFO 364 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n", 365 s->s_type->name, 366 sb_rdonly(s) ? " readonly" : "", 367 MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 368 return 0; 369 } 370 371 void __init mount_block_root(char *name, int flags) 372 { 373 struct page *page = alloc_page(GFP_KERNEL); 374 char *fs_names = page_address(page); 375 char *p; 376 #ifdef CONFIG_BLOCK 377 char b[BDEVNAME_SIZE]; 378 #else 379 const char *b = name; 380 #endif 381 382 get_fs_names(fs_names); 383 retry: 384 for (p = fs_names; *p; p += strlen(p)+1) { 385 int err = do_mount_root(name, p, flags, root_mount_data); 386 switch (err) { 387 case 0: 388 goto out; 389 case -EACCES: 390 case -EINVAL: 391 continue; 392 } 393 /* 394 * Allow the user to distinguish between failed sys_open 395 * and bad superblock on root device. 396 * and give them a list of the available devices 397 */ 398 #ifdef CONFIG_BLOCK 399 __bdevname(ROOT_DEV, b); 400 #endif 401 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n", 402 root_device_name, b, err); 403 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); 404 405 printk_all_partitions(); 406 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT 407 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " 408 "explicit textual name for \"root=\" boot option.\n"); 409 #endif 410 panic("VFS: Unable to mount root fs on %s", b); 411 } 412 if (!(flags & SB_RDONLY)) { 413 flags |= SB_RDONLY; 414 goto retry; 415 } 416 417 printk("List of all partitions:\n"); 418 printk_all_partitions(); 419 printk("No filesystem could mount root, tried: "); 420 for (p = fs_names; *p; p += strlen(p)+1) 421 printk(" %s", p); 422 printk("\n"); 423 #ifdef CONFIG_BLOCK 424 __bdevname(ROOT_DEV, b); 425 #endif 426 panic("VFS: Unable to mount root fs on %s", b); 427 out: 428 put_page(page); 429 } 430 431 #ifdef CONFIG_ROOT_NFS 432 433 #define NFSROOT_TIMEOUT_MIN 5 434 #define NFSROOT_TIMEOUT_MAX 30 435 #define NFSROOT_RETRY_MAX 5 436 437 static int __init mount_nfs_root(void) 438 { 439 char *root_dev, *root_data; 440 unsigned int timeout; 441 int try, err; 442 443 err = nfs_root_data(&root_dev, &root_data); 444 if (err != 0) 445 return 0; 446 447 /* 448 * The server or network may not be ready, so try several 449 * times. Stop after a few tries in case the client wants 450 * to fall back to other boot methods. 451 */ 452 timeout = NFSROOT_TIMEOUT_MIN; 453 for (try = 1; ; try++) { 454 err = do_mount_root(root_dev, "nfs", 455 root_mountflags, root_data); 456 if (err == 0) 457 return 1; 458 if (try > NFSROOT_RETRY_MAX) 459 break; 460 461 /* Wait, in case the server refused us immediately */ 462 ssleep(timeout); 463 timeout <<= 1; 464 if (timeout > NFSROOT_TIMEOUT_MAX) 465 timeout = NFSROOT_TIMEOUT_MAX; 466 } 467 return 0; 468 } 469 #endif 470 471 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD) 472 void __init change_floppy(char *fmt, ...) 473 { 474 struct termios termios; 475 char buf[80]; 476 char c; 477 int fd; 478 va_list args; 479 va_start(args, fmt); 480 vsprintf(buf, fmt, args); 481 va_end(args); 482 fd = ksys_open("/dev/root", O_RDWR | O_NDELAY, 0); 483 if (fd >= 0) { 484 ksys_ioctl(fd, FDEJECT, 0); 485 ksys_close(fd); 486 } 487 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); 488 fd = ksys_open("/dev/console", O_RDWR, 0); 489 if (fd >= 0) { 490 ksys_ioctl(fd, TCGETS, (long)&termios); 491 termios.c_lflag &= ~ICANON; 492 ksys_ioctl(fd, TCSETSF, (long)&termios); 493 ksys_read(fd, &c, 1); 494 termios.c_lflag |= ICANON; 495 ksys_ioctl(fd, TCSETSF, (long)&termios); 496 ksys_close(fd); 497 } 498 } 499 #endif 500 501 void __init mount_root(void) 502 { 503 #ifdef CONFIG_ROOT_NFS 504 if (ROOT_DEV == Root_NFS) { 505 if (mount_nfs_root()) 506 return; 507 508 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n"); 509 ROOT_DEV = Root_FD0; 510 } 511 #endif 512 #ifdef CONFIG_BLK_DEV_FD 513 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) { 514 /* rd_doload is 2 for a dual initrd/ramload setup */ 515 if (rd_doload==2) { 516 if (rd_load_disk(1)) { 517 ROOT_DEV = Root_RAM1; 518 root_device_name = NULL; 519 } 520 } else 521 change_floppy("root floppy"); 522 } 523 #endif 524 #ifdef CONFIG_BLOCK 525 { 526 int err = create_dev("/dev/root", ROOT_DEV); 527 528 if (err < 0) 529 pr_emerg("Failed to create /dev/root: %d\n", err); 530 mount_block_root("/dev/root", root_mountflags); 531 } 532 #endif 533 } 534 535 /* 536 * Prepare the namespace - decide what/where to mount, load ramdisks, etc. 537 */ 538 void __init prepare_namespace(void) 539 { 540 int is_floppy; 541 542 if (root_delay) { 543 printk(KERN_INFO "Waiting %d sec before mounting root device...\n", 544 root_delay); 545 ssleep(root_delay); 546 } 547 548 /* 549 * wait for the known devices to complete their probing 550 * 551 * Note: this is a potential source of long boot delays. 552 * For example, it is not atypical to wait 5 seconds here 553 * for the touchpad of a laptop to initialize. 554 */ 555 wait_for_device_probe(); 556 557 md_run_setup(); 558 559 if (saved_root_name[0]) { 560 root_device_name = saved_root_name; 561 if (!strncmp(root_device_name, "mtd", 3) || 562 !strncmp(root_device_name, "ubi", 3)) { 563 mount_block_root(root_device_name, root_mountflags); 564 goto out; 565 } 566 ROOT_DEV = name_to_dev_t(root_device_name); 567 if (strncmp(root_device_name, "/dev/", 5) == 0) 568 root_device_name += 5; 569 } 570 571 if (initrd_load()) 572 goto out; 573 574 /* wait for any asynchronous scanning to complete */ 575 if ((ROOT_DEV == 0) && root_wait) { 576 printk(KERN_INFO "Waiting for root device %s...\n", 577 saved_root_name); 578 while (driver_probe_done() != 0 || 579 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0) 580 msleep(5); 581 async_synchronize_full(); 582 } 583 584 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR; 585 586 if (is_floppy && rd_doload && rd_load_disk(0)) 587 ROOT_DEV = Root_RAM0; 588 589 mount_root(); 590 out: 591 devtmpfs_mount("dev"); 592 ksys_mount(".", "/", NULL, MS_MOVE, NULL); 593 ksys_chroot("."); 594 } 595 596 static bool is_tmpfs; 597 static struct dentry *rootfs_mount(struct file_system_type *fs_type, 598 int flags, const char *dev_name, void *data) 599 { 600 static unsigned long once; 601 void *fill = ramfs_fill_super; 602 603 if (test_and_set_bit(0, &once)) 604 return ERR_PTR(-ENODEV); 605 606 if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs) 607 fill = shmem_fill_super; 608 609 return mount_nodev(fs_type, flags, data, fill); 610 } 611 612 static struct file_system_type rootfs_fs_type = { 613 .name = "rootfs", 614 .mount = rootfs_mount, 615 .kill_sb = kill_litter_super, 616 }; 617 618 int __init init_rootfs(void) 619 { 620 int err = register_filesystem(&rootfs_fs_type); 621 622 if (err) 623 return err; 624 625 if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] && 626 (!root_fs_names || strstr(root_fs_names, "tmpfs"))) { 627 err = shmem_init(); 628 is_tmpfs = true; 629 } else { 630 err = init_ramfs_fs(); 631 } 632 633 if (err) 634 unregister_filesystem(&rootfs_fs_type); 635 636 return err; 637 } 638