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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#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
38int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
39
40int root_mountflags = MS_RDONLY | MS_SILENT;
41static char * __initdata root_device_name;
42static char __initdata saved_root_name[64];
43static int root_wait;
44
45dev_t ROOT_DEV;
46
47static 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
54static int __init readonly(char *str)
55{
56 if (*str)
57 return 0;
58 root_mountflags |= MS_RDONLY;
59 return 1;
60}
61
62static 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
74struct 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 */
86static 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;
98no_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 */
116static 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
168no_offset:
169 put_device(dev);
170done:
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) <hex_major><hex_minor> device number in hexadecimal represents itself
186 * no leading 0x, for example b302.
187 * 2) /dev/nfs represents Root_NFS (0xff)
188 * 3) /dev/<disk_name> represents the device number of disk
189 * 4) /dev/<disk_name><decimal> represents the device number
190 * of partition - device number of disk plus the partition number
191 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
192 * used when disk name of partitioned disk ends on a digit.
193 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
194 * unique id of a partition if the partition table provides it.
195 * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
196 * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
197 * filled hex representation of the 32-bit "NT disk signature", and PP
198 * is a zero-filled hex representation of the 1-based partition number.
199 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
200 * a partition with a known unique id.
201 * 8) <major>:<minor> major and minor number of the device separated by
202 * a colon.
203 *
204 * If name doesn't have fall into the categories above, we return (0,0).
205 * block_class is used to check if something is a disk name. If the disk
206 * name contains slashes, the device name has them replaced with
207 * bangs.
208 */
209
210dev_t name_to_dev_t(const char *name)
211{
212 char s[32];
213 char *p;
214 dev_t res = 0;
215 int part;
216
217#ifdef CONFIG_BLOCK
218 if (strncmp(name, "PARTUUID=", 9) == 0) {
219 name += 9;
220 res = devt_from_partuuid(name);
221 if (!res)
222 goto fail;
223 goto done;
224 }
225#endif
226
227 if (strncmp(name, "/dev/", 5) != 0) {
228 unsigned maj, min, offset;
229 char dummy;
230
231 if ((sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) ||
232 (sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3)) {
233 res = MKDEV(maj, min);
234 if (maj != MAJOR(res) || min != MINOR(res))
235 goto fail;
236 } else {
237 res = new_decode_dev(simple_strtoul(name, &p, 16));
238 if (*p)
239 goto fail;
240 }
241 goto done;
242 }
243
244 name += 5;
245 res = Root_NFS;
246 if (strcmp(name, "nfs") == 0)
247 goto done;
248 res = Root_RAM0;
249 if (strcmp(name, "ram") == 0)
250 goto done;
251
252 if (strlen(name) > 31)
253 goto fail;
254 strcpy(s, name);
255 for (p = s; *p; p++)
256 if (*p == '/')
257 *p = '!';
258 res = blk_lookup_devt(s, 0);
259 if (res)
260 goto done;
261
262 /*
263 * try non-existent, but valid partition, which may only exist
264 * after revalidating the disk, like partitioned md devices
265 */
266 while (p > s && isdigit(p[-1]))
267 p--;
268 if (p == s || !*p || *p == '0')
269 goto fail;
270
271 /* try disk name without <part number> */
272 part = simple_strtoul(p, NULL, 10);
273 *p = '\0';
274 res = blk_lookup_devt(s, part);
275 if (res)
276 goto done;
277
278 /* try disk name without p<part number> */
279 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
280 goto fail;
281 p[-1] = '\0';
282 res = blk_lookup_devt(s, part);
283 if (res)
284 goto done;
285
286fail:
287 return 0;
288done:
289 return res;
290}
291EXPORT_SYMBOL_GPL(name_to_dev_t);
292
293static int __init root_dev_setup(char *line)
294{
295 strlcpy(saved_root_name, line, sizeof(saved_root_name));
296 return 1;
297}
298
299__setup("root=", root_dev_setup);
300
301static int __init rootwait_setup(char *str)
302{
303 if (*str)
304 return 0;
305 root_wait = 1;
306 return 1;
307}
308
309__setup("rootwait", rootwait_setup);
310
311static char * __initdata root_mount_data;
312static int __init root_data_setup(char *str)
313{
314 root_mount_data = str;
315 return 1;
316}
317
318static char * __initdata root_fs_names;
319static int __init fs_names_setup(char *str)
320{
321 root_fs_names = str;
322 return 1;
323}
324
325static unsigned int __initdata root_delay;
326static int __init root_delay_setup(char *str)
327{
328 root_delay = simple_strtoul(str, NULL, 0);
329 return 1;
330}
331
332__setup("rootflags=", root_data_setup);
333__setup("rootfstype=", fs_names_setup);
334__setup("rootdelay=", root_delay_setup);
335
336static void __init get_fs_names(char *page)
337{
338 char *s = page;
339
340 if (root_fs_names) {
341 strcpy(page, root_fs_names);
342 while (*s++) {
343 if (s[-1] == ',')
344 s[-1] = '\0';
345 }
346 } else {
347 int len = get_filesystem_list(page);
348 char *p, *next;
349
350 page[len] = '\0';
351 for (p = page-1; p; p = next) {
352 next = strchr(++p, '\n');
353 if (*p++ != '\t')
354 continue;
355 while ((*s++ = *p++) != '\n')
356 ;
357 s[-1] = '\0';
358 }
359 }
360 *s = '\0';
361}
362
363static int __init do_mount_root(char *name, char *fs, int flags, void *data)
364{
365 struct super_block *s;
366 int err = ksys_mount(name, "/root", fs, flags, data);
367 if (err)
368 return err;
369
370 ksys_chdir("/root");
371 s = current->fs->pwd.dentry->d_sb;
372 ROOT_DEV = s->s_dev;
373 printk(KERN_INFO
374 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
375 s->s_type->name,
376 sb_rdonly(s) ? " readonly" : "",
377 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
378 return 0;
379}
380
381void __init mount_block_root(char *name, int flags)
382{
383 struct page *page = alloc_page(GFP_KERNEL);
384 char *fs_names = page_address(page);
385 char *p;
386#ifdef CONFIG_BLOCK
387 char b[BDEVNAME_SIZE];
388#else
389 const char *b = name;
390#endif
391
392 get_fs_names(fs_names);
393retry:
394 for (p = fs_names; *p; p += strlen(p)+1) {
395 int err = do_mount_root(name, p, flags, root_mount_data);
396 switch (err) {
397 case 0:
398 goto out;
399 case -EACCES:
400 case -EINVAL:
401 continue;
402 }
403 /*
404 * Allow the user to distinguish between failed sys_open
405 * and bad superblock on root device.
406 * and give them a list of the available devices
407 */
408#ifdef CONFIG_BLOCK
409 __bdevname(ROOT_DEV, b);
410#endif
411 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
412 root_device_name, b, err);
413 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
414
415 printk_all_partitions();
416#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
417 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
418 "explicit textual name for \"root=\" boot option.\n");
419#endif
420 panic("VFS: Unable to mount root fs on %s", b);
421 }
422 if (!(flags & SB_RDONLY)) {
423 flags |= SB_RDONLY;
424 goto retry;
425 }
426
427 printk("List of all partitions:\n");
428 printk_all_partitions();
429 printk("No filesystem could mount root, tried: ");
430 for (p = fs_names; *p; p += strlen(p)+1)
431 printk(" %s", p);
432 printk("\n");
433#ifdef CONFIG_BLOCK
434 __bdevname(ROOT_DEV, b);
435#endif
436 panic("VFS: Unable to mount root fs on %s", b);
437out:
438 put_page(page);
439}
440
441#ifdef CONFIG_ROOT_NFS
442
443#define NFSROOT_TIMEOUT_MIN 5
444#define NFSROOT_TIMEOUT_MAX 30
445#define NFSROOT_RETRY_MAX 5
446
447static int __init mount_nfs_root(void)
448{
449 char *root_dev, *root_data;
450 unsigned int timeout;
451 int try, err;
452
453 err = nfs_root_data(&root_dev, &root_data);
454 if (err != 0)
455 return 0;
456
457 /*
458 * The server or network may not be ready, so try several
459 * times. Stop after a few tries in case the client wants
460 * to fall back to other boot methods.
461 */
462 timeout = NFSROOT_TIMEOUT_MIN;
463 for (try = 1; ; try++) {
464 err = do_mount_root(root_dev, "nfs",
465 root_mountflags, root_data);
466 if (err == 0)
467 return 1;
468 if (try > NFSROOT_RETRY_MAX)
469 break;
470
471 /* Wait, in case the server refused us immediately */
472 ssleep(timeout);
473 timeout <<= 1;
474 if (timeout > NFSROOT_TIMEOUT_MAX)
475 timeout = NFSROOT_TIMEOUT_MAX;
476 }
477 return 0;
478}
479#endif
480
481#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
482void __init change_floppy(char *fmt, ...)
483{
484 struct termios termios;
485 char buf[80];
486 char c;
487 int fd;
488 va_list args;
489 va_start(args, fmt);
490 vsprintf(buf, fmt, args);
491 va_end(args);
492 fd = ksys_open("/dev/root", O_RDWR | O_NDELAY, 0);
493 if (fd >= 0) {
494 ksys_ioctl(fd, FDEJECT, 0);
495 ksys_close(fd);
496 }
497 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
498 fd = ksys_open("/dev/console", O_RDWR, 0);
499 if (fd >= 0) {
500 ksys_ioctl(fd, TCGETS, (long)&termios);
501 termios.c_lflag &= ~ICANON;
502 ksys_ioctl(fd, TCSETSF, (long)&termios);
503 ksys_read(fd, &c, 1);
504 termios.c_lflag |= ICANON;
505 ksys_ioctl(fd, TCSETSF, (long)&termios);
506 ksys_close(fd);
507 }
508}
509#endif
510
511void __init mount_root(void)
512{
513#ifdef CONFIG_ROOT_NFS
514 if (ROOT_DEV == Root_NFS) {
515 if (mount_nfs_root())
516 return;
517
518 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
519 ROOT_DEV = Root_FD0;
520 }
521#endif
522#ifdef CONFIG_BLK_DEV_FD
523 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
524 /* rd_doload is 2 for a dual initrd/ramload setup */
525 if (rd_doload==2) {
526 if (rd_load_disk(1)) {
527 ROOT_DEV = Root_RAM1;
528 root_device_name = NULL;
529 }
530 } else
531 change_floppy("root floppy");
532 }
533#endif
534#ifdef CONFIG_BLOCK
535 {
536 int err = create_dev("/dev/root", ROOT_DEV);
537
538 if (err < 0)
539 pr_emerg("Failed to create /dev/root: %d\n", err);
540 mount_block_root("/dev/root", root_mountflags);
541 }
542#endif
543}
544
545/*
546 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
547 */
548void __init prepare_namespace(void)
549{
550 int is_floppy;
551
552 if (root_delay) {
553 printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
554 root_delay);
555 ssleep(root_delay);
556 }
557
558 /*
559 * wait for the known devices to complete their probing
560 *
561 * Note: this is a potential source of long boot delays.
562 * For example, it is not atypical to wait 5 seconds here
563 * for the touchpad of a laptop to initialize.
564 */
565 wait_for_device_probe();
566
567 md_run_setup();
568
569 if (saved_root_name[0]) {
570 root_device_name = saved_root_name;
571 if (!strncmp(root_device_name, "mtd", 3) ||
572 !strncmp(root_device_name, "ubi", 3)) {
573 mount_block_root(root_device_name, root_mountflags);
574 goto out;
575 }
576 ROOT_DEV = name_to_dev_t(root_device_name);
577 if (strncmp(root_device_name, "/dev/", 5) == 0)
578 root_device_name += 5;
579 }
580
581 if (initrd_load())
582 goto out;
583
584 /* wait for any asynchronous scanning to complete */
585 if ((ROOT_DEV == 0) && root_wait) {
586 printk(KERN_INFO "Waiting for root device %s...\n",
587 saved_root_name);
588 while (driver_probe_done() != 0 ||
589 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
590 msleep(5);
591 async_synchronize_full();
592 }
593
594 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
595
596 if (is_floppy && rd_doload && rd_load_disk(0))
597 ROOT_DEV = Root_RAM0;
598
599 mount_root();
600out:
601 devtmpfs_mount("dev");
602 ksys_mount(".", "/", NULL, MS_MOVE, NULL);
603 ksys_chroot(".");
604}
605
606static bool is_tmpfs;
607static struct dentry *rootfs_mount(struct file_system_type *fs_type,
608 int flags, const char *dev_name, void *data)
609{
610 static unsigned long once;
611 void *fill = ramfs_fill_super;
612
613 if (test_and_set_bit(0, &once))
614 return ERR_PTR(-ENODEV);
615
616 if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
617 fill = shmem_fill_super;
618
619 return mount_nodev(fs_type, flags, data, fill);
620}
621
622static struct file_system_type rootfs_fs_type = {
623 .name = "rootfs",
624 .mount = rootfs_mount,
625 .kill_sb = kill_litter_super,
626};
627
628int __init init_rootfs(void)
629{
630 int err = register_filesystem(&rootfs_fs_type);
631
632 if (err)
633 return err;
634
635 if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
636 (!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
637 err = shmem_init();
638 is_tmpfs = true;
639 } else {
640 err = init_ramfs_fs();
641 }
642
643 if (err)
644 unregister_filesystem(&rootfs_fs_type);
645
646 return err;
647}
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
36int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
37
38int root_mountflags = MS_RDONLY | MS_SILENT;
39static char * __initdata root_device_name;
40static char __initdata saved_root_name[64];
41static int root_wait;
42
43dev_t ROOT_DEV;
44
45static 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
52static int __init readonly(char *str)
53{
54 if (*str)
55 return 0;
56 root_mountflags |= MS_RDONLY;
57 return 1;
58}
59
60static 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 */
79static 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;
91no_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 */
109static 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
158no_offset:
159 put_device(dev);
160done:
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
186dev_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
260fail:
261 return 0;
262done:
263 return res;
264}
265
266static 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
274static 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
284static char * __initdata root_mount_data;
285static int __init root_data_setup(char *str)
286{
287 root_mount_data = str;
288 return 1;
289}
290
291static char * __initdata root_fs_names;
292static int __init fs_names_setup(char *str)
293{
294 root_fs_names = str;
295 return 1;
296}
297
298static unsigned int __initdata root_delay;
299static 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
309static 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
336static 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
354void __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);
366retry:
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);
408out:
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
418static 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)
453void __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
482void __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 */
514void __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();
566out:
567 devtmpfs_mount("dev");
568 sys_mount(".", "/", NULL, MS_MOVE, NULL);
569 sys_chroot(".");
570}