Root/
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 | #include <linux/shmem_fs.h> |
31 | |
32 | #include <linux/nfs_fs.h> |
33 | #include <linux/nfs_fs_sb.h> |
34 | #include <linux/nfs_mount.h> |
35 | |
36 | #include "do_mounts.h" |
37 | |
38 | int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */ |
39 | |
40 | int root_mountflags = MS_RDONLY | MS_SILENT; |
41 | static char * __initdata root_device_name; |
42 | static char __initdata saved_root_name[64]; |
43 | static int root_wait; |
44 | |
45 | dev_t ROOT_DEV; |
46 | |
47 | static int __init load_ramdisk(char *str) |
48 | { |
49 | rd_doload = simple_strtol(str,NULL,0) & 3; |
50 | return 1; |
51 | } |
52 | __setup("load_ramdisk=", load_ramdisk); |
53 | |
54 | static int __init readonly(char *str) |
55 | { |
56 | if (*str) |
57 | return 0; |
58 | root_mountflags |= MS_RDONLY; |
59 | return 1; |
60 | } |
61 | |
62 | static int __init readwrite(char *str) |
63 | { |
64 | if (*str) |
65 | return 0; |
66 | root_mountflags &= ~MS_RDONLY; |
67 | return 1; |
68 | } |
69 | |
70 | __setup("ro", readonly); |
71 | __setup("rw", readwrite); |
72 | |
73 | #ifdef CONFIG_BLOCK |
74 | struct uuidcmp { |
75 | const char *uuid; |
76 | int len; |
77 | }; |
78 | |
79 | /** |
80 | * match_dev_by_uuid - callback for finding a partition using its uuid |
81 | * @dev: device passed in by the caller |
82 | * @data: opaque pointer to the desired struct uuidcmp to match |
83 | * |
84 | * Returns 1 if the device matches, and 0 otherwise. |
85 | */ |
86 | static int match_dev_by_uuid(struct device *dev, const void *data) |
87 | { |
88 | const struct uuidcmp *cmp = data; |
89 | struct hd_struct *part = dev_to_part(dev); |
90 | |
91 | if (!part->info) |
92 | goto no_match; |
93 | |
94 | if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len)) |
95 | goto no_match; |
96 | |
97 | return 1; |
98 | no_match: |
99 | return 0; |
100 | } |
101 | |
102 | |
103 | /** |
104 | * devt_from_partuuid - looks up the dev_t of a partition by its UUID |
105 | * @uuid_str: char array containing ascii UUID |
106 | * |
107 | * The function will return the first partition which contains a matching |
108 | * UUID value in its partition_meta_info struct. This does not search |
109 | * by filesystem UUIDs. |
110 | * |
111 | * If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be |
112 | * extracted and used as an offset from the partition identified by the UUID. |
113 | * |
114 | * Returns the matching dev_t on success or 0 on failure. |
115 | */ |
116 | static dev_t devt_from_partuuid(const char *uuid_str) |
117 | { |
118 | dev_t res = 0; |
119 | struct uuidcmp cmp; |
120 | struct device *dev = NULL; |
121 | struct gendisk *disk; |
122 | struct hd_struct *part; |
123 | int offset = 0; |
124 | bool clear_root_wait = false; |
125 | char *slash; |
126 | |
127 | cmp.uuid = uuid_str; |
128 | |
129 | slash = strchr(uuid_str, '/'); |
130 | /* Check for optional partition number offset attributes. */ |
131 | if (slash) { |
132 | char c = 0; |
133 | /* Explicitly fail on poor PARTUUID syntax. */ |
134 | if (sscanf(slash + 1, |
135 | "PARTNROFF=%d%c", &offset, &c) != 1) { |
136 | clear_root_wait = true; |
137 | goto done; |
138 | } |
139 | cmp.len = slash - uuid_str; |
140 | } else { |
141 | cmp.len = strlen(uuid_str); |
142 | } |
143 | |
144 | if (!cmp.len) { |
145 | clear_root_wait = true; |
146 | goto done; |
147 | } |
148 | |
149 | dev = class_find_device(&block_class, NULL, &cmp, |
150 | &match_dev_by_uuid); |
151 | if (!dev) |
152 | goto done; |
153 | |
154 | res = dev->devt; |
155 | |
156 | /* Attempt to find the partition by offset. */ |
157 | if (!offset) |
158 | goto no_offset; |
159 | |
160 | res = 0; |
161 | disk = part_to_disk(dev_to_part(dev)); |
162 | part = disk_get_part(disk, dev_to_part(dev)->partno + offset); |
163 | if (part) { |
164 | res = part_devt(part); |
165 | put_device(part_to_dev(part)); |
166 | } |
167 | |
168 | no_offset: |
169 | put_device(dev); |
170 | done: |
171 | if (clear_root_wait) { |
172 | pr_err("VFS: PARTUUID= is invalid.\n" |
173 | "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n"); |
174 | if (root_wait) |
175 | pr_err("Disabling rootwait; root= is invalid.\n"); |
176 | root_wait = 0; |
177 | } |
178 | return res; |
179 | } |
180 | #endif |
181 | |
182 | /* |
183 | * Convert a name into device number. We accept the following variants: |
184 | * |
185 | * 1) device number in hexadecimal represents itself |
186 | * 2) /dev/nfs represents Root_NFS (0xff) |
187 | * 3) /dev/<disk_name> represents the device number of disk |
188 | * 4) /dev/<disk_name><decimal> represents the device number |
189 | * of partition - device number of disk plus the partition number |
190 | * 5) /dev/<disk_name>p<decimal> - same as the above, that form is |
191 | * used when disk name of partitioned disk ends on a digit. |
192 | * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the |
193 | * unique id of a partition if the partition table provides it. |
194 | * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS |
195 | * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- |
196 | * filled hex representation of the 32-bit "NT disk signature", and PP |
197 | * is a zero-filled hex representation of the 1-based partition number. |
198 | * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to |
199 | * a partition with a known unique id. |
200 | * 8) <major>:<minor> major and minor number of the device separated by |
201 | * a colon. |
202 | * |
203 | * If name doesn't have fall into the categories above, we return (0,0). |
204 | * block_class is used to check if something is a disk name. If the disk |
205 | * name contains slashes, the device name has them replaced with |
206 | * bangs. |
207 | */ |
208 | |
209 | dev_t name_to_dev_t(char *name) |
210 | { |
211 | char s[32]; |
212 | char *p; |
213 | dev_t res = 0; |
214 | int part; |
215 | |
216 | #ifdef CONFIG_BLOCK |
217 | if (strncmp(name, "PARTUUID=", 9) == 0) { |
218 | name += 9; |
219 | res = devt_from_partuuid(name); |
220 | if (!res) |
221 | goto fail; |
222 | goto done; |
223 | } |
224 | #endif |
225 | |
226 | if (strncmp(name, "/dev/", 5) != 0) { |
227 | unsigned maj, min; |
228 | |
229 | if (sscanf(name, "%u:%u", &maj, &min) == 2) { |
230 | res = MKDEV(maj, min); |
231 | if (maj != MAJOR(res) || min != MINOR(res)) |
232 | goto fail; |
233 | } else { |
234 | res = new_decode_dev(simple_strtoul(name, &p, 16)); |
235 | if (*p) |
236 | goto fail; |
237 | } |
238 | goto done; |
239 | } |
240 | |
241 | name += 5; |
242 | res = Root_NFS; |
243 | if (strcmp(name, "nfs") == 0) |
244 | goto done; |
245 | res = Root_RAM0; |
246 | if (strcmp(name, "ram") == 0) |
247 | goto done; |
248 | |
249 | if (strlen(name) > 31) |
250 | goto fail; |
251 | strcpy(s, name); |
252 | for (p = s; *p; p++) |
253 | if (*p == '/') |
254 | *p = '!'; |
255 | res = blk_lookup_devt(s, 0); |
256 | if (res) |
257 | goto done; |
258 | |
259 | /* |
260 | * try non-existent, but valid partition, which may only exist |
261 | * after revalidating the disk, like partitioned md devices |
262 | */ |
263 | while (p > s && isdigit(p[-1])) |
264 | p--; |
265 | if (p == s || !*p || *p == '0') |
266 | goto fail; |
267 | |
268 | /* try disk name without <part number> */ |
269 | part = simple_strtoul(p, NULL, 10); |
270 | *p = '\0'; |
271 | res = blk_lookup_devt(s, part); |
272 | if (res) |
273 | goto done; |
274 | |
275 | /* try disk name without p<part number> */ |
276 | if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') |
277 | goto fail; |
278 | p[-1] = '\0'; |
279 | res = blk_lookup_devt(s, part); |
280 | if (res) |
281 | goto done; |
282 | |
283 | fail: |
284 | return 0; |
285 | done: |
286 | return res; |
287 | } |
288 | |
289 | static int __init root_dev_setup(char *line) |
290 | { |
291 | strlcpy(saved_root_name, line, sizeof(saved_root_name)); |
292 | return 1; |
293 | } |
294 | |
295 | __setup("root=", root_dev_setup); |
296 | |
297 | static int __init rootwait_setup(char *str) |
298 | { |
299 | if (*str) |
300 | return 0; |
301 | root_wait = 1; |
302 | return 1; |
303 | } |
304 | |
305 | __setup("rootwait", rootwait_setup); |
306 | |
307 | static char * __initdata root_mount_data; |
308 | static int __init root_data_setup(char *str) |
309 | { |
310 | root_mount_data = str; |
311 | return 1; |
312 | } |
313 | |
314 | static char * __initdata root_fs_names; |
315 | static int __init fs_names_setup(char *str) |
316 | { |
317 | root_fs_names = str; |
318 | return 1; |
319 | } |
320 | |
321 | static unsigned int __initdata root_delay; |
322 | static int __init root_delay_setup(char *str) |
323 | { |
324 | root_delay = simple_strtoul(str, NULL, 0); |
325 | return 1; |
326 | } |
327 | |
328 | __setup("rootflags=", root_data_setup); |
329 | __setup("rootfstype=", fs_names_setup); |
330 | __setup("rootdelay=", root_delay_setup); |
331 | |
332 | static void __init get_fs_names(char *page) |
333 | { |
334 | char *s = page; |
335 | |
336 | if (root_fs_names) { |
337 | strcpy(page, root_fs_names); |
338 | while (*s++) { |
339 | if (s[-1] == ',') |
340 | s[-1] = '\0'; |
341 | } |
342 | } else { |
343 | int len = get_filesystem_list(page); |
344 | char *p, *next; |
345 | |
346 | page[len] = '\0'; |
347 | for (p = page-1; p; p = next) { |
348 | next = strchr(++p, '\n'); |
349 | if (*p++ != '\t') |
350 | continue; |
351 | while ((*s++ = *p++) != '\n') |
352 | ; |
353 | s[-1] = '\0'; |
354 | } |
355 | } |
356 | *s = '\0'; |
357 | } |
358 | |
359 | static int __init do_mount_root(char *name, char *fs, int flags, void *data) |
360 | { |
361 | struct super_block *s; |
362 | int err = sys_mount(name, "/root", fs, flags, data); |
363 | if (err) |
364 | return err; |
365 | |
366 | sys_chdir("/root"); |
367 | s = current->fs->pwd.dentry->d_sb; |
368 | ROOT_DEV = s->s_dev; |
369 | printk(KERN_INFO |
370 | "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n", |
371 | s->s_type->name, |
372 | s->s_flags & MS_RDONLY ? " readonly" : "", |
373 | MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); |
374 | return 0; |
375 | } |
376 | |
377 | void __init mount_block_root(char *name, int flags) |
378 | { |
379 | struct page *page = alloc_page(GFP_KERNEL | |
380 | __GFP_NOTRACK_FALSE_POSITIVE); |
381 | char *fs_names = page_address(page); |
382 | char *p; |
383 | #ifdef CONFIG_BLOCK |
384 | char b[BDEVNAME_SIZE]; |
385 | #else |
386 | const char *b = name; |
387 | #endif |
388 | |
389 | get_fs_names(fs_names); |
390 | retry: |
391 | for (p = fs_names; *p; p += strlen(p)+1) { |
392 | int err = do_mount_root(name, p, flags, root_mount_data); |
393 | switch (err) { |
394 | case 0: |
395 | goto out; |
396 | case -EACCES: |
397 | flags |= MS_RDONLY; |
398 | goto retry; |
399 | case -EINVAL: |
400 | continue; |
401 | } |
402 | /* |
403 | * Allow the user to distinguish between failed sys_open |
404 | * and bad superblock on root device. |
405 | * and give them a list of the available devices |
406 | */ |
407 | #ifdef CONFIG_BLOCK |
408 | __bdevname(ROOT_DEV, b); |
409 | #endif |
410 | printk("VFS: Cannot open root device \"%s\" or %s: error %d\n", |
411 | root_device_name, b, err); |
412 | printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); |
413 | |
414 | printk_all_partitions(); |
415 | #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT |
416 | printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " |
417 | "explicit textual name for \"root=\" boot option.\n"); |
418 | #endif |
419 | panic("VFS: Unable to mount root fs on %s", b); |
420 | } |
421 | |
422 | printk("List of all partitions:\n"); |
423 | printk_all_partitions(); |
424 | printk("No filesystem could mount root, tried: "); |
425 | for (p = fs_names; *p; p += strlen(p)+1) |
426 | printk(" %s", p); |
427 | printk("\n"); |
428 | #ifdef CONFIG_BLOCK |
429 | __bdevname(ROOT_DEV, b); |
430 | #endif |
431 | panic("VFS: Unable to mount root fs on %s", b); |
432 | out: |
433 | put_page(page); |
434 | } |
435 | |
436 | #ifdef CONFIG_ROOT_NFS |
437 | |
438 | #define NFSROOT_TIMEOUT_MIN 5 |
439 | #define NFSROOT_TIMEOUT_MAX 30 |
440 | #define NFSROOT_RETRY_MAX 5 |
441 | |
442 | static int __init mount_nfs_root(void) |
443 | { |
444 | char *root_dev, *root_data; |
445 | unsigned int timeout; |
446 | int try, err; |
447 | |
448 | err = nfs_root_data(&root_dev, &root_data); |
449 | if (err != 0) |
450 | return 0; |
451 | |
452 | /* |
453 | * The server or network may not be ready, so try several |
454 | * times. Stop after a few tries in case the client wants |
455 | * to fall back to other boot methods. |
456 | */ |
457 | timeout = NFSROOT_TIMEOUT_MIN; |
458 | for (try = 1; ; try++) { |
459 | err = do_mount_root(root_dev, "nfs", |
460 | root_mountflags, root_data); |
461 | if (err == 0) |
462 | return 1; |
463 | if (try > NFSROOT_RETRY_MAX) |
464 | break; |
465 | |
466 | /* Wait, in case the server refused us immediately */ |
467 | ssleep(timeout); |
468 | timeout <<= 1; |
469 | if (timeout > NFSROOT_TIMEOUT_MAX) |
470 | timeout = NFSROOT_TIMEOUT_MAX; |
471 | } |
472 | return 0; |
473 | } |
474 | #endif |
475 | |
476 | #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD) |
477 | void __init change_floppy(char *fmt, ...) |
478 | { |
479 | struct termios termios; |
480 | char buf[80]; |
481 | char c; |
482 | int fd; |
483 | va_list args; |
484 | va_start(args, fmt); |
485 | vsprintf(buf, fmt, args); |
486 | va_end(args); |
487 | fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0); |
488 | if (fd >= 0) { |
489 | sys_ioctl(fd, FDEJECT, 0); |
490 | sys_close(fd); |
491 | } |
492 | printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf); |
493 | fd = sys_open("/dev/console", O_RDWR, 0); |
494 | if (fd >= 0) { |
495 | sys_ioctl(fd, TCGETS, (long)&termios); |
496 | termios.c_lflag &= ~ICANON; |
497 | sys_ioctl(fd, TCSETSF, (long)&termios); |
498 | sys_read(fd, &c, 1); |
499 | termios.c_lflag |= ICANON; |
500 | sys_ioctl(fd, TCSETSF, (long)&termios); |
501 | sys_close(fd); |
502 | } |
503 | } |
504 | #endif |
505 | |
506 | void __init mount_root(void) |
507 | { |
508 | #ifdef CONFIG_ROOT_NFS |
509 | if (ROOT_DEV == Root_NFS) { |
510 | if (mount_nfs_root()) |
511 | return; |
512 | |
513 | printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n"); |
514 | ROOT_DEV = Root_FD0; |
515 | } |
516 | #endif |
517 | #ifdef CONFIG_BLK_DEV_FD |
518 | if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) { |
519 | /* rd_doload is 2 for a dual initrd/ramload setup */ |
520 | if (rd_doload==2) { |
521 | if (rd_load_disk(1)) { |
522 | ROOT_DEV = Root_RAM1; |
523 | root_device_name = NULL; |
524 | } |
525 | } else |
526 | change_floppy("root floppy"); |
527 | } |
528 | #endif |
529 | #ifdef CONFIG_BLOCK |
530 | create_dev("/dev/root", ROOT_DEV); |
531 | mount_block_root("/dev/root", root_mountflags); |
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(100); |
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 | sys_mount(".", "/", NULL, MS_MOVE, NULL); |
593 | sys_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 |
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jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9