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 20 #include <linux/nfs_fs.h> 21 #include <linux/nfs_fs_sb.h> 22 #include <linux/nfs_mount.h> 23 24 #include "do_mounts.h" 25 26 int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */ 27 28 int root_mountflags = MS_RDONLY | MS_SILENT; 29 static char * __initdata root_device_name; 30 static char __initdata saved_root_name[64]; 31 static int root_wait; 32 33 dev_t ROOT_DEV; 34 35 static int __init load_ramdisk(char *str) 36 { 37 rd_doload = simple_strtol(str,NULL,0) & 3; 38 return 1; 39 } 40 __setup("load_ramdisk=", load_ramdisk); 41 42 static int __init readonly(char *str) 43 { 44 if (*str) 45 return 0; 46 root_mountflags |= MS_RDONLY; 47 return 1; 48 } 49 50 static int __init readwrite(char *str) 51 { 52 if (*str) 53 return 0; 54 root_mountflags &= ~MS_RDONLY; 55 return 1; 56 } 57 58 __setup("ro", readonly); 59 __setup("rw", readwrite); 60 61 #ifdef CONFIG_BLOCK 62 /** 63 * match_dev_by_uuid - callback for finding a partition using its uuid 64 * @dev: device passed in by the caller 65 * @data: opaque pointer to a 36 byte char array with a UUID 66 * 67 * Returns 1 if the device matches, and 0 otherwise. 68 */ 69 static int match_dev_by_uuid(struct device *dev, void *data) 70 { 71 u8 *uuid = data; 72 struct hd_struct *part = dev_to_part(dev); 73 74 if (!part->info) 75 goto no_match; 76 77 if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid))) 78 goto no_match; 79 80 return 1; 81 no_match: 82 return 0; 83 } 84 85 86 /** 87 * devt_from_partuuid - looks up the dev_t of a partition by its UUID 88 * @uuid: min 36 byte char array containing a hex ascii UUID 89 * 90 * The function will return the first partition which contains a matching 91 * UUID value in its partition_meta_info struct. This does not search 92 * by filesystem UUIDs. 93 * 94 * If @uuid is followed by a "/PARTNROFF=%d", then the number will be 95 * extracted and used as an offset from the partition identified by the UUID. 96 * 97 * Returns the matching dev_t on success or 0 on failure. 98 */ 99 static dev_t devt_from_partuuid(char *uuid_str) 100 { 101 dev_t res = 0; 102 struct device *dev = NULL; 103 u8 uuid[16]; 104 struct gendisk *disk; 105 struct hd_struct *part; 106 int offset = 0; 107 108 if (strlen(uuid_str) < 36) 109 goto done; 110 111 /* Check for optional partition number offset attributes. */ 112 if (uuid_str[36]) { 113 char c = 0; 114 /* Explicitly fail on poor PARTUUID syntax. */ 115 if (sscanf(&uuid_str[36], 116 "/PARTNROFF=%d%c", &offset, &c) != 1) { 117 printk(KERN_ERR "VFS: PARTUUID= is invalid.\n" 118 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n"); 119 if (root_wait) 120 printk(KERN_ERR 121 "Disabling rootwait; root= is invalid.\n"); 122 root_wait = 0; 123 goto done; 124 } 125 } 126 127 /* Pack the requested UUID in the expected format. */ 128 part_pack_uuid(uuid_str, uuid); 129 130 dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid); 131 if (!dev) 132 goto done; 133 134 res = dev->devt; 135 136 /* Attempt to find the partition by offset. */ 137 if (!offset) 138 goto no_offset; 139 140 res = 0; 141 disk = part_to_disk(dev_to_part(dev)); 142 part = disk_get_part(disk, dev_to_part(dev)->partno + offset); 143 if (part) { 144 res = part_devt(part); 145 put_device(part_to_dev(part)); 146 } 147 148 no_offset: 149 put_device(dev); 150 done: 151 return res; 152 } 153 #endif 154 155 /* 156 * Convert a name into device number. We accept the following variants: 157 * 158 * 1) device number in hexadecimal represents itself 159 * 2) /dev/nfs represents Root_NFS (0xff) 160 * 3) /dev/<disk_name> represents the device number of disk 161 * 4) /dev/<disk_name><decimal> represents the device number 162 * of partition - device number of disk plus the partition number 163 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is 164 * used when disk name of partitioned disk ends on a digit. 165 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the 166 * unique id of a partition if the partition table provides it. 167 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to 168 * a partition with a known unique id. 169 * 170 * If name doesn't have fall into the categories above, we return (0,0). 171 * block_class is used to check if something is a disk name. If the disk 172 * name contains slashes, the device name has them replaced with 173 * bangs. 174 */ 175 176 dev_t name_to_dev_t(char *name) 177 { 178 char s[32]; 179 char *p; 180 dev_t res = 0; 181 int part; 182 183 #ifdef CONFIG_BLOCK 184 if (strncmp(name, "PARTUUID=", 9) == 0) { 185 name += 9; 186 res = devt_from_partuuid(name); 187 if (!res) 188 goto fail; 189 goto done; 190 } 191 #endif 192 193 if (strncmp(name, "/dev/", 5) != 0) { 194 unsigned maj, min; 195 196 if (sscanf(name, "%u:%u", &maj, &min) == 2) { 197 res = MKDEV(maj, min); 198 if (maj != MAJOR(res) || min != MINOR(res)) 199 goto fail; 200 } else { 201 res = new_decode_dev(simple_strtoul(name, &p, 16)); 202 if (*p) 203 goto fail; 204 } 205 goto done; 206 } 207 208 name += 5; 209 res = Root_NFS; 210 if (strcmp(name, "nfs") == 0) 211 goto done; 212 res = Root_RAM0; 213 if (strcmp(name, "ram") == 0) 214 goto done; 215 216 if (strlen(name) > 31) 217 goto fail; 218 strcpy(s, name); 219 for (p = s; *p; p++) 220 if (*p == '/') 221 *p = '!'; 222 res = blk_lookup_devt(s, 0); 223 if (res) 224 goto done; 225 226 /* 227 * try non-existent, but valid partition, which may only exist 228 * after revalidating the disk, like partitioned md devices 229 */ 230 while (p > s && isdigit(p[-1])) 231 p--; 232 if (p == s || !*p || *p == '0') 233 goto fail; 234 235 /* try disk name without <part number> */ 236 part = simple_strtoul(p, NULL, 10); 237 *p = '\0'; 238 res = blk_lookup_devt(s, part); 239 if (res) 240 goto done; 241 242 /* try disk name without p<part number> */ 243 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') 244 goto fail; 245 p[-1] = '\0'; 246 res = blk_lookup_devt(s, part); 247 if (res) 248 goto done; 249 250 fail: 251 return 0; 252 done: 253 return res; 254 } 255 256 static int __init root_dev_setup(char *line) 257 { 258 strlcpy(saved_root_name, line, sizeof(saved_root_name)); 259 return 1; 260 } 261 262 __setup("root=", root_dev_setup); 263 264 static int __init rootwait_setup(char *str) 265 { 266 if (*str) 267 return 0; 268 root_wait = 1; 269 return 1; 270 } 271 272 __setup("rootwait", rootwait_setup); 273 274 static char * __initdata root_mount_data; 275 static int __init root_data_setup(char *str) 276 { 277 root_mount_data = str; 278 return 1; 279 } 280 281 static char * __initdata root_fs_names; 282 static int __init fs_names_setup(char *str) 283 { 284 root_fs_names = str; 285 return 1; 286 } 287 288 static unsigned int __initdata root_delay; 289 static int __init root_delay_setup(char *str) 290 { 291 root_delay = simple_strtoul(str, NULL, 0); 292 return 1; 293 } 294 295 __setup("rootflags=", root_data_setup); 296 __setup("rootfstype=", fs_names_setup); 297 __setup("rootdelay=", root_delay_setup); 298 299 static void __init get_fs_names(char *page) 300 { 301 char *s = page; 302 303 if (root_fs_names) { 304 strcpy(page, root_fs_names); 305 while (*s++) { 306 if (s[-1] == ',') 307 s[-1] = '\0'; 308 } 309 } else { 310 int len = get_filesystem_list(page); 311 char *p, *next; 312 313 page[len] = '\0'; 314 for (p = page-1; p; p = next) { 315 next = strchr(++p, '\n'); 316 if (*p++ != '\t') 317 continue; 318 while ((*s++ = *p++) != '\n') 319 ; 320 s[-1] = '\0'; 321 } 322 } 323 *s = '\0'; 324 } 325 326 static int __init do_mount_root(char *name, char *fs, int flags, void *data) 327 { 328 int err = sys_mount(name, "/root", fs, flags, data); 329 if (err) 330 return err; 331 332 sys_chdir((const char __user __force *)"/root"); 333 ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev; 334 printk(KERN_INFO 335 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n", 336 current->fs->pwd.mnt->mnt_sb->s_type->name, 337 current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ? 338 " readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 339 return 0; 340 } 341 342 void __init mount_block_root(char *name, int flags) 343 { 344 char *fs_names = __getname_gfp(GFP_KERNEL 345 | __GFP_NOTRACK_FALSE_POSITIVE); 346 char *p; 347 #ifdef CONFIG_BLOCK 348 char b[BDEVNAME_SIZE]; 349 #else 350 const char *b = name; 351 #endif 352 353 get_fs_names(fs_names); 354 retry: 355 for (p = fs_names; *p; p += strlen(p)+1) { 356 int err = do_mount_root(name, p, flags, root_mount_data); 357 switch (err) { 358 case 0: 359 goto out; 360 case -EACCES: 361 flags |= MS_RDONLY; 362 goto retry; 363 case -EINVAL: 364 continue; 365 } 366 /* 367 * Allow the user to distinguish between failed sys_open 368 * and bad superblock on root device. 369 * and give them a list of the available devices 370 */ 371 #ifdef CONFIG_BLOCK 372 __bdevname(ROOT_DEV, b); 373 #endif 374 printk("VFS: Cannot open root device \"%s\" or %s\n", 375 root_device_name, b); 376 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); 377 378 printk_all_partitions(); 379 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT 380 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " 381 "explicit textual name for \"root=\" boot option.\n"); 382 #endif 383 panic("VFS: Unable to mount root fs on %s", b); 384 } 385 386 printk("List of all partitions:\n"); 387 printk_all_partitions(); 388 printk("No filesystem could mount root, tried: "); 389 for (p = fs_names; *p; p += strlen(p)+1) 390 printk(" %s", p); 391 printk("\n"); 392 #ifdef CONFIG_BLOCK 393 __bdevname(ROOT_DEV, b); 394 #endif 395 panic("VFS: Unable to mount root fs on %s", b); 396 out: 397 putname(fs_names); 398 } 399 400 #ifdef CONFIG_ROOT_NFS 401 static int __init mount_nfs_root(void) 402 { 403 char *root_dev, *root_data; 404 405 if (nfs_root_data(&root_dev, &root_data) != 0) 406 return 0; 407 if (do_mount_root(root_dev, "nfs", root_mountflags, root_data) != 0) 408 return 0; 409 return 1; 410 } 411 #endif 412 413 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD) 414 void __init change_floppy(char *fmt, ...) 415 { 416 struct termios termios; 417 char buf[80]; 418 char c; 419 int fd; 420 va_list args; 421 va_start(args, fmt); 422 vsprintf(buf, fmt, args); 423 va_end(args); 424 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0); 425 if (fd >= 0) { 426 sys_ioctl(fd, FDEJECT, 0); 427 sys_close(fd); 428 } 429 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); 430 fd = sys_open("/dev/console", O_RDWR, 0); 431 if (fd >= 0) { 432 sys_ioctl(fd, TCGETS, (long)&termios); 433 termios.c_lflag &= ~ICANON; 434 sys_ioctl(fd, TCSETSF, (long)&termios); 435 sys_read(fd, &c, 1); 436 termios.c_lflag |= ICANON; 437 sys_ioctl(fd, TCSETSF, (long)&termios); 438 sys_close(fd); 439 } 440 } 441 #endif 442 443 void __init mount_root(void) 444 { 445 #ifdef CONFIG_ROOT_NFS 446 if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) { 447 if (mount_nfs_root()) 448 return; 449 450 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n"); 451 ROOT_DEV = Root_FD0; 452 } 453 #endif 454 #ifdef CONFIG_BLK_DEV_FD 455 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) { 456 /* rd_doload is 2 for a dual initrd/ramload setup */ 457 if (rd_doload==2) { 458 if (rd_load_disk(1)) { 459 ROOT_DEV = Root_RAM1; 460 root_device_name = NULL; 461 } 462 } else 463 change_floppy("root floppy"); 464 } 465 #endif 466 #ifdef CONFIG_BLOCK 467 create_dev("/dev/root", ROOT_DEV); 468 mount_block_root("/dev/root", root_mountflags); 469 #endif 470 } 471 472 /* 473 * Prepare the namespace - decide what/where to mount, load ramdisks, etc. 474 */ 475 void __init prepare_namespace(void) 476 { 477 int is_floppy; 478 479 if (root_delay) { 480 printk(KERN_INFO "Waiting %dsec before mounting root device...\n", 481 root_delay); 482 ssleep(root_delay); 483 } 484 485 /* 486 * wait for the known devices to complete their probing 487 * 488 * Note: this is a potential source of long boot delays. 489 * For example, it is not atypical to wait 5 seconds here 490 * for the touchpad of a laptop to initialize. 491 */ 492 wait_for_device_probe(); 493 494 md_run_setup(); 495 496 if (saved_root_name[0]) { 497 root_device_name = saved_root_name; 498 if (!strncmp(root_device_name, "mtd", 3) || 499 !strncmp(root_device_name, "ubi", 3)) { 500 mount_block_root(root_device_name, root_mountflags); 501 goto out; 502 } 503 ROOT_DEV = name_to_dev_t(root_device_name); 504 if (strncmp(root_device_name, "/dev/", 5) == 0) 505 root_device_name += 5; 506 } 507 508 if (initrd_load()) 509 goto out; 510 511 /* wait for any asynchronous scanning to complete */ 512 if ((ROOT_DEV == 0) && root_wait) { 513 printk(KERN_INFO "Waiting for root device %s...\n", 514 saved_root_name); 515 while (driver_probe_done() != 0 || 516 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0) 517 msleep(100); 518 async_synchronize_full(); 519 } 520 521 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR; 522 523 if (is_floppy && rd_doload && rd_load_disk(0)) 524 ROOT_DEV = Root_RAM0; 525 526 mount_root(); 527 out: 528 devtmpfs_mount("dev"); 529 sys_mount(".", "/", NULL, MS_MOVE, NULL); 530 sys_chroot((const char __user __force *)"."); 531 } 532