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