1 /* 2 * Many of the syscalls used in this file expect some of the arguments 3 * to be __user pointers not __kernel pointers. To limit the sparse 4 * noise, turn off sparse checking for this file. 5 */ 6 #ifdef __CHECKER__ 7 #undef __CHECKER__ 8 #warning "Sparse checking disabled for this file" 9 #endif 10 11 #include <linux/module.h> 12 #include <linux/sched.h> 13 #include <linux/ctype.h> 14 #include <linux/fd.h> 15 #include <linux/tty.h> 16 #include <linux/suspend.h> 17 #include <linux/root_dev.h> 18 #include <linux/security.h> 19 #include <linux/delay.h> 20 #include <linux/genhd.h> 21 #include <linux/mount.h> 22 #include <linux/device.h> 23 #include <linux/init.h> 24 #include <linux/fs.h> 25 #include <linux/initrd.h> 26 #include <linux/async.h> 27 #include <linux/fs_struct.h> 28 #include <linux/slab.h> 29 30 #include <linux/nfs_fs.h> 31 #include <linux/nfs_fs_sb.h> 32 #include <linux/nfs_mount.h> 33 34 #include "do_mounts.h" 35 36 int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */ 37 38 int root_mountflags = MS_RDONLY | MS_SILENT; 39 static char * __initdata root_device_name; 40 static char __initdata saved_root_name[64]; 41 static int root_wait; 42 43 dev_t ROOT_DEV; 44 45 static int __init load_ramdisk(char *str) 46 { 47 rd_doload = simple_strtol(str,NULL,0) & 3; 48 return 1; 49 } 50 __setup("load_ramdisk=", load_ramdisk); 51 52 static int __init readonly(char *str) 53 { 54 if (*str) 55 return 0; 56 root_mountflags |= MS_RDONLY; 57 return 1; 58 } 59 60 static int __init readwrite(char *str) 61 { 62 if (*str) 63 return 0; 64 root_mountflags &= ~MS_RDONLY; 65 return 1; 66 } 67 68 __setup("ro", readonly); 69 __setup("rw", readwrite); 70 71 #ifdef CONFIG_BLOCK 72 /** 73 * match_dev_by_uuid - callback for finding a partition using its uuid 74 * @dev: device passed in by the caller 75 * @data: opaque pointer to a 36 byte char array with a UUID 76 * 77 * Returns 1 if the device matches, and 0 otherwise. 78 */ 79 static int match_dev_by_uuid(struct device *dev, void *data) 80 { 81 u8 *uuid = data; 82 struct hd_struct *part = dev_to_part(dev); 83 84 if (!part->info) 85 goto no_match; 86 87 if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid))) 88 goto no_match; 89 90 return 1; 91 no_match: 92 return 0; 93 } 94 95 96 /** 97 * devt_from_partuuid - looks up the dev_t of a partition by its UUID 98 * @uuid: min 36 byte char array containing a hex ascii UUID 99 * 100 * The function will return the first partition which contains a matching 101 * UUID value in its partition_meta_info struct. This does not search 102 * by filesystem UUIDs. 103 * 104 * If @uuid is followed by a "/PARTNROFF=%d", then the number will be 105 * extracted and used as an offset from the partition identified by the UUID. 106 * 107 * Returns the matching dev_t on success or 0 on failure. 108 */ 109 static dev_t devt_from_partuuid(char *uuid_str) 110 { 111 dev_t res = 0; 112 struct device *dev = NULL; 113 u8 uuid[16]; 114 struct gendisk *disk; 115 struct hd_struct *part; 116 int offset = 0; 117 118 if (strlen(uuid_str) < 36) 119 goto done; 120 121 /* Check for optional partition number offset attributes. */ 122 if (uuid_str[36]) { 123 char c = 0; 124 /* Explicitly fail on poor PARTUUID syntax. */ 125 if (sscanf(&uuid_str[36], 126 "/PARTNROFF=%d%c", &offset, &c) != 1) { 127 printk(KERN_ERR "VFS: PARTUUID= is invalid.\n" 128 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n"); 129 if (root_wait) 130 printk(KERN_ERR 131 "Disabling rootwait; root= is invalid.\n"); 132 root_wait = 0; 133 goto done; 134 } 135 } 136 137 /* Pack the requested UUID in the expected format. */ 138 part_pack_uuid(uuid_str, uuid); 139 140 dev = class_find_device(&block_class, NULL, uuid, &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 return res; 162 } 163 #endif 164 165 /* 166 * Convert a name into device number. We accept the following variants: 167 * 168 * 1) device number in hexadecimal represents itself 169 * 2) /dev/nfs represents Root_NFS (0xff) 170 * 3) /dev/<disk_name> represents the device number of disk 171 * 4) /dev/<disk_name><decimal> represents the device number 172 * of partition - device number of disk plus the partition number 173 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is 174 * used when disk name of partitioned disk ends on a digit. 175 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the 176 * unique id of a partition if the partition table provides it. 177 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to 178 * a partition with a known unique id. 179 * 180 * If name doesn't have fall into the categories above, we return (0,0). 181 * block_class is used to check if something is a disk name. If the disk 182 * name contains slashes, the device name has them replaced with 183 * bangs. 184 */ 185 186 dev_t name_to_dev_t(char *name) 187 { 188 char s[32]; 189 char *p; 190 dev_t res = 0; 191 int part; 192 193 #ifdef CONFIG_BLOCK 194 if (strncmp(name, "PARTUUID=", 9) == 0) { 195 name += 9; 196 res = devt_from_partuuid(name); 197 if (!res) 198 goto fail; 199 goto done; 200 } 201 #endif 202 203 if (strncmp(name, "/dev/", 5) != 0) { 204 unsigned maj, min; 205 206 if (sscanf(name, "%u:%u", &maj, &min) == 2) { 207 res = MKDEV(maj, min); 208 if (maj != MAJOR(res) || min != MINOR(res)) 209 goto fail; 210 } else { 211 res = new_decode_dev(simple_strtoul(name, &p, 16)); 212 if (*p) 213 goto fail; 214 } 215 goto done; 216 } 217 218 name += 5; 219 res = Root_NFS; 220 if (strcmp(name, "nfs") == 0) 221 goto done; 222 res = Root_RAM0; 223 if (strcmp(name, "ram") == 0) 224 goto done; 225 226 if (strlen(name) > 31) 227 goto fail; 228 strcpy(s, name); 229 for (p = s; *p; p++) 230 if (*p == '/') 231 *p = '!'; 232 res = blk_lookup_devt(s, 0); 233 if (res) 234 goto done; 235 236 /* 237 * try non-existent, but valid partition, which may only exist 238 * after revalidating the disk, like partitioned md devices 239 */ 240 while (p > s && isdigit(p[-1])) 241 p--; 242 if (p == s || !*p || *p == '0') 243 goto fail; 244 245 /* try disk name without <part number> */ 246 part = simple_strtoul(p, NULL, 10); 247 *p = '\0'; 248 res = blk_lookup_devt(s, part); 249 if (res) 250 goto done; 251 252 /* try disk name without p<part number> */ 253 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') 254 goto fail; 255 p[-1] = '\0'; 256 res = blk_lookup_devt(s, part); 257 if (res) 258 goto done; 259 260 fail: 261 return 0; 262 done: 263 return res; 264 } 265 266 static int __init root_dev_setup(char *line) 267 { 268 strlcpy(saved_root_name, line, sizeof(saved_root_name)); 269 return 1; 270 } 271 272 __setup("root=", root_dev_setup); 273 274 static int __init rootwait_setup(char *str) 275 { 276 if (*str) 277 return 0; 278 root_wait = 1; 279 return 1; 280 } 281 282 __setup("rootwait", rootwait_setup); 283 284 static char * __initdata root_mount_data; 285 static int __init root_data_setup(char *str) 286 { 287 root_mount_data = str; 288 return 1; 289 } 290 291 static char * __initdata root_fs_names; 292 static int __init fs_names_setup(char *str) 293 { 294 root_fs_names = str; 295 return 1; 296 } 297 298 static unsigned int __initdata root_delay; 299 static int __init root_delay_setup(char *str) 300 { 301 root_delay = simple_strtoul(str, NULL, 0); 302 return 1; 303 } 304 305 __setup("rootflags=", root_data_setup); 306 __setup("rootfstype=", fs_names_setup); 307 __setup("rootdelay=", root_delay_setup); 308 309 static void __init get_fs_names(char *page) 310 { 311 char *s = page; 312 313 if (root_fs_names) { 314 strcpy(page, root_fs_names); 315 while (*s++) { 316 if (s[-1] == ',') 317 s[-1] = '\0'; 318 } 319 } else { 320 int len = get_filesystem_list(page); 321 char *p, *next; 322 323 page[len] = '\0'; 324 for (p = page-1; p; p = next) { 325 next = strchr(++p, '\n'); 326 if (*p++ != '\t') 327 continue; 328 while ((*s++ = *p++) != '\n') 329 ; 330 s[-1] = '\0'; 331 } 332 } 333 *s = '\0'; 334 } 335 336 static int __init do_mount_root(char *name, char *fs, int flags, void *data) 337 { 338 struct super_block *s; 339 int err = sys_mount(name, "/root", fs, flags, data); 340 if (err) 341 return err; 342 343 sys_chdir("/root"); 344 s = current->fs->pwd.dentry->d_sb; 345 ROOT_DEV = s->s_dev; 346 printk(KERN_INFO 347 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n", 348 s->s_type->name, 349 s->s_flags & MS_RDONLY ? " readonly" : "", 350 MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 351 return 0; 352 } 353 354 void __init mount_block_root(char *name, int flags) 355 { 356 char *fs_names = __getname_gfp(GFP_KERNEL 357 | __GFP_NOTRACK_FALSE_POSITIVE); 358 char *p; 359 #ifdef CONFIG_BLOCK 360 char b[BDEVNAME_SIZE]; 361 #else 362 const char *b = name; 363 #endif 364 365 get_fs_names(fs_names); 366 retry: 367 for (p = fs_names; *p; p += strlen(p)+1) { 368 int err = do_mount_root(name, p, flags, root_mount_data); 369 switch (err) { 370 case 0: 371 goto out; 372 case -EACCES: 373 flags |= MS_RDONLY; 374 goto retry; 375 case -EINVAL: 376 continue; 377 } 378 /* 379 * Allow the user to distinguish between failed sys_open 380 * and bad superblock on root device. 381 * and give them a list of the available devices 382 */ 383 #ifdef CONFIG_BLOCK 384 __bdevname(ROOT_DEV, b); 385 #endif 386 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n", 387 root_device_name, b, err); 388 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); 389 390 printk_all_partitions(); 391 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT 392 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " 393 "explicit textual name for \"root=\" boot option.\n"); 394 #endif 395 panic("VFS: Unable to mount root fs on %s", b); 396 } 397 398 printk("List of all partitions:\n"); 399 printk_all_partitions(); 400 printk("No filesystem could mount root, tried: "); 401 for (p = fs_names; *p; p += strlen(p)+1) 402 printk(" %s", p); 403 printk("\n"); 404 #ifdef CONFIG_BLOCK 405 __bdevname(ROOT_DEV, b); 406 #endif 407 panic("VFS: Unable to mount root fs on %s", b); 408 out: 409 putname(fs_names); 410 } 411 412 #ifdef CONFIG_ROOT_NFS 413 414 #define NFSROOT_TIMEOUT_MIN 5 415 #define NFSROOT_TIMEOUT_MAX 30 416 #define NFSROOT_RETRY_MAX 5 417 418 static int __init mount_nfs_root(void) 419 { 420 char *root_dev, *root_data; 421 unsigned int timeout; 422 int try, err; 423 424 err = nfs_root_data(&root_dev, &root_data); 425 if (err != 0) 426 return 0; 427 428 /* 429 * The server or network may not be ready, so try several 430 * times. Stop after a few tries in case the client wants 431 * to fall back to other boot methods. 432 */ 433 timeout = NFSROOT_TIMEOUT_MIN; 434 for (try = 1; ; try++) { 435 err = do_mount_root(root_dev, "nfs", 436 root_mountflags, root_data); 437 if (err == 0) 438 return 1; 439 if (try > NFSROOT_RETRY_MAX) 440 break; 441 442 /* Wait, in case the server refused us immediately */ 443 ssleep(timeout); 444 timeout <<= 1; 445 if (timeout > NFSROOT_TIMEOUT_MAX) 446 timeout = NFSROOT_TIMEOUT_MAX; 447 } 448 return 0; 449 } 450 #endif 451 452 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD) 453 void __init change_floppy(char *fmt, ...) 454 { 455 struct termios termios; 456 char buf[80]; 457 char c; 458 int fd; 459 va_list args; 460 va_start(args, fmt); 461 vsprintf(buf, fmt, args); 462 va_end(args); 463 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0); 464 if (fd >= 0) { 465 sys_ioctl(fd, FDEJECT, 0); 466 sys_close(fd); 467 } 468 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); 469 fd = sys_open("/dev/console", O_RDWR, 0); 470 if (fd >= 0) { 471 sys_ioctl(fd, TCGETS, (long)&termios); 472 termios.c_lflag &= ~ICANON; 473 sys_ioctl(fd, TCSETSF, (long)&termios); 474 sys_read(fd, &c, 1); 475 termios.c_lflag |= ICANON; 476 sys_ioctl(fd, TCSETSF, (long)&termios); 477 sys_close(fd); 478 } 479 } 480 #endif 481 482 void __init mount_root(void) 483 { 484 #ifdef CONFIG_ROOT_NFS 485 if (ROOT_DEV == Root_NFS) { 486 if (mount_nfs_root()) 487 return; 488 489 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n"); 490 ROOT_DEV = Root_FD0; 491 } 492 #endif 493 #ifdef CONFIG_BLK_DEV_FD 494 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) { 495 /* rd_doload is 2 for a dual initrd/ramload setup */ 496 if (rd_doload==2) { 497 if (rd_load_disk(1)) { 498 ROOT_DEV = Root_RAM1; 499 root_device_name = NULL; 500 } 501 } else 502 change_floppy("root floppy"); 503 } 504 #endif 505 #ifdef CONFIG_BLOCK 506 create_dev("/dev/root", ROOT_DEV); 507 mount_block_root("/dev/root", root_mountflags); 508 #endif 509 } 510 511 /* 512 * Prepare the namespace - decide what/where to mount, load ramdisks, etc. 513 */ 514 void __init prepare_namespace(void) 515 { 516 int is_floppy; 517 518 if (root_delay) { 519 printk(KERN_INFO "Waiting %dsec before mounting root device...\n", 520 root_delay); 521 ssleep(root_delay); 522 } 523 524 /* 525 * wait for the known devices to complete their probing 526 * 527 * Note: this is a potential source of long boot delays. 528 * For example, it is not atypical to wait 5 seconds here 529 * for the touchpad of a laptop to initialize. 530 */ 531 wait_for_device_probe(); 532 533 md_run_setup(); 534 535 if (saved_root_name[0]) { 536 root_device_name = saved_root_name; 537 if (!strncmp(root_device_name, "mtd", 3) || 538 !strncmp(root_device_name, "ubi", 3)) { 539 mount_block_root(root_device_name, root_mountflags); 540 goto out; 541 } 542 ROOT_DEV = name_to_dev_t(root_device_name); 543 if (strncmp(root_device_name, "/dev/", 5) == 0) 544 root_device_name += 5; 545 } 546 547 if (initrd_load()) 548 goto out; 549 550 /* wait for any asynchronous scanning to complete */ 551 if ((ROOT_DEV == 0) && root_wait) { 552 printk(KERN_INFO "Waiting for root device %s...\n", 553 saved_root_name); 554 while (driver_probe_done() != 0 || 555 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0) 556 msleep(100); 557 async_synchronize_full(); 558 } 559 560 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR; 561 562 if (is_floppy && rd_doload && rd_load_disk(0)) 563 ROOT_DEV = Root_RAM0; 564 565 mount_root(); 566 out: 567 devtmpfs_mount("dev"); 568 sys_mount(".", "/", NULL, MS_MOVE, NULL); 569 sys_chroot("."); 570 } 571