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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
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}
1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/module.h>
3#include <linux/sched.h>
4#include <linux/ctype.h>
5#include <linux/fd.h>
6#include <linux/tty.h>
7#include <linux/suspend.h>
8#include <linux/root_dev.h>
9#include <linux/security.h>
10#include <linux/delay.h>
11#include <linux/genhd.h>
12#include <linux/mount.h>
13#include <linux/device.h>
14#include <linux/init.h>
15#include <linux/fs.h>
16#include <linux/initrd.h>
17#include <linux/async.h>
18#include <linux/fs_struct.h>
19#include <linux/slab.h>
20#include <linux/ramfs.h>
21#include <linux/shmem_fs.h>
22
23#include <linux/nfs_fs.h>
24#include <linux/nfs_fs_sb.h>
25#include <linux/nfs_mount.h>
26#include <linux/raid/detect.h>
27#include <uapi/linux/mount.h>
28
29#include "do_mounts.h"
30
31int root_mountflags = MS_RDONLY | MS_SILENT;
32static char * __initdata root_device_name;
33static char __initdata saved_root_name[64];
34static int root_wait;
35
36dev_t ROOT_DEV;
37
38static int __init load_ramdisk(char *str)
39{
40 pr_warn("ignoring the deprecated load_ramdisk= option\n");
41 return 1;
42}
43__setup("load_ramdisk=", load_ramdisk);
44
45static int __init readonly(char *str)
46{
47 if (*str)
48 return 0;
49 root_mountflags |= MS_RDONLY;
50 return 1;
51}
52
53static int __init readwrite(char *str)
54{
55 if (*str)
56 return 0;
57 root_mountflags &= ~MS_RDONLY;
58 return 1;
59}
60
61__setup("ro", readonly);
62__setup("rw", readwrite);
63
64#ifdef CONFIG_BLOCK
65struct uuidcmp {
66 const char *uuid;
67 int len;
68};
69
70/**
71 * match_dev_by_uuid - callback for finding a partition using its uuid
72 * @dev: device passed in by the caller
73 * @data: opaque pointer to the desired struct uuidcmp to match
74 *
75 * Returns 1 if the device matches, and 0 otherwise.
76 */
77static int match_dev_by_uuid(struct device *dev, const void *data)
78{
79 const struct uuidcmp *cmp = data;
80 struct hd_struct *part = dev_to_part(dev);
81
82 if (!part->info)
83 goto no_match;
84
85 if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len))
86 goto no_match;
87
88 return 1;
89no_match:
90 return 0;
91}
92
93
94/**
95 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
96 * @uuid_str: char array containing ascii UUID
97 *
98 * The function will return the first partition which contains a matching
99 * UUID value in its partition_meta_info struct. This does not search
100 * by filesystem UUIDs.
101 *
102 * If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be
103 * extracted and used as an offset from the partition identified by the UUID.
104 *
105 * Returns the matching dev_t on success or 0 on failure.
106 */
107static dev_t devt_from_partuuid(const char *uuid_str)
108{
109 dev_t res = 0;
110 struct uuidcmp cmp;
111 struct device *dev = NULL;
112 struct gendisk *disk;
113 struct hd_struct *part;
114 int offset = 0;
115 bool clear_root_wait = false;
116 char *slash;
117
118 cmp.uuid = uuid_str;
119
120 slash = strchr(uuid_str, '/');
121 /* Check for optional partition number offset attributes. */
122 if (slash) {
123 char c = 0;
124 /* Explicitly fail on poor PARTUUID syntax. */
125 if (sscanf(slash + 1,
126 "PARTNROFF=%d%c", &offset, &c) != 1) {
127 clear_root_wait = true;
128 goto done;
129 }
130 cmp.len = slash - uuid_str;
131 } else {
132 cmp.len = strlen(uuid_str);
133 }
134
135 if (!cmp.len) {
136 clear_root_wait = true;
137 goto done;
138 }
139
140 dev = class_find_device(&block_class, NULL, &cmp,
141 &match_dev_by_uuid);
142 if (!dev)
143 goto done;
144
145 res = dev->devt;
146
147 /* Attempt to find the partition by offset. */
148 if (!offset)
149 goto no_offset;
150
151 res = 0;
152 disk = part_to_disk(dev_to_part(dev));
153 part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
154 if (part) {
155 res = part_devt(part);
156 put_device(part_to_dev(part));
157 }
158
159no_offset:
160 put_device(dev);
161done:
162 if (clear_root_wait) {
163 pr_err("VFS: PARTUUID= is invalid.\n"
164 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
165 if (root_wait)
166 pr_err("Disabling rootwait; root= is invalid.\n");
167 root_wait = 0;
168 }
169 return res;
170}
171
172/**
173 * match_dev_by_label - callback for finding a partition using its label
174 * @dev: device passed in by the caller
175 * @data: opaque pointer to the label to match
176 *
177 * Returns 1 if the device matches, and 0 otherwise.
178 */
179static int match_dev_by_label(struct device *dev, const void *data)
180{
181 const char *label = data;
182 struct hd_struct *part = dev_to_part(dev);
183
184 if (part->info && !strcmp(label, part->info->volname))
185 return 1;
186
187 return 0;
188}
189#endif
190
191/*
192 * Convert a name into device number. We accept the following variants:
193 *
194 * 1) <hex_major><hex_minor> device number in hexadecimal represents itself
195 * no leading 0x, for example b302.
196 * 2) /dev/nfs represents Root_NFS (0xff)
197 * 3) /dev/<disk_name> represents the device number of disk
198 * 4) /dev/<disk_name><decimal> represents the device number
199 * of partition - device number of disk plus the partition number
200 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
201 * used when disk name of partitioned disk ends on a digit.
202 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
203 * unique id of a partition if the partition table provides it.
204 * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
205 * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
206 * filled hex representation of the 32-bit "NT disk signature", and PP
207 * is a zero-filled hex representation of the 1-based partition number.
208 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
209 * a partition with a known unique id.
210 * 8) <major>:<minor> major and minor number of the device separated by
211 * a colon.
212 * 9) PARTLABEL=<name> with name being the GPT partition label.
213 * MSDOS partitions do not support labels!
214 * 10) /dev/cifs represents Root_CIFS (0xfe)
215 *
216 * If name doesn't have fall into the categories above, we return (0,0).
217 * block_class is used to check if something is a disk name. If the disk
218 * name contains slashes, the device name has them replaced with
219 * bangs.
220 */
221
222dev_t name_to_dev_t(const char *name)
223{
224 char s[32];
225 char *p;
226 dev_t res = 0;
227 int part;
228
229#ifdef CONFIG_BLOCK
230 if (strncmp(name, "PARTUUID=", 9) == 0) {
231 name += 9;
232 res = devt_from_partuuid(name);
233 if (!res)
234 goto fail;
235 goto done;
236 } else if (strncmp(name, "PARTLABEL=", 10) == 0) {
237 struct device *dev;
238
239 dev = class_find_device(&block_class, NULL, name + 10,
240 &match_dev_by_label);
241 if (!dev)
242 goto fail;
243
244 res = dev->devt;
245 put_device(dev);
246 goto done;
247 }
248#endif
249
250 if (strncmp(name, "/dev/", 5) != 0) {
251 unsigned maj, min, offset;
252 char dummy;
253
254 if ((sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2) ||
255 (sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3)) {
256 res = MKDEV(maj, min);
257 if (maj != MAJOR(res) || min != MINOR(res))
258 goto fail;
259 } else {
260 res = new_decode_dev(simple_strtoul(name, &p, 16));
261 if (*p)
262 goto fail;
263 }
264 goto done;
265 }
266
267 name += 5;
268 res = Root_NFS;
269 if (strcmp(name, "nfs") == 0)
270 goto done;
271 res = Root_CIFS;
272 if (strcmp(name, "cifs") == 0)
273 goto done;
274 res = Root_RAM0;
275 if (strcmp(name, "ram") == 0)
276 goto done;
277
278 if (strlen(name) > 31)
279 goto fail;
280 strcpy(s, name);
281 for (p = s; *p; p++)
282 if (*p == '/')
283 *p = '!';
284 res = blk_lookup_devt(s, 0);
285 if (res)
286 goto done;
287
288 /*
289 * try non-existent, but valid partition, which may only exist
290 * after revalidating the disk, like partitioned md devices
291 */
292 while (p > s && isdigit(p[-1]))
293 p--;
294 if (p == s || !*p || *p == '0')
295 goto fail;
296
297 /* try disk name without <part number> */
298 part = simple_strtoul(p, NULL, 10);
299 *p = '\0';
300 res = blk_lookup_devt(s, part);
301 if (res)
302 goto done;
303
304 /* try disk name without p<part number> */
305 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
306 goto fail;
307 p[-1] = '\0';
308 res = blk_lookup_devt(s, part);
309 if (res)
310 goto done;
311
312fail:
313 return 0;
314done:
315 return res;
316}
317EXPORT_SYMBOL_GPL(name_to_dev_t);
318
319static int __init root_dev_setup(char *line)
320{
321 strlcpy(saved_root_name, line, sizeof(saved_root_name));
322 return 1;
323}
324
325__setup("root=", root_dev_setup);
326
327static int __init rootwait_setup(char *str)
328{
329 if (*str)
330 return 0;
331 root_wait = 1;
332 return 1;
333}
334
335__setup("rootwait", rootwait_setup);
336
337static char * __initdata root_mount_data;
338static int __init root_data_setup(char *str)
339{
340 root_mount_data = str;
341 return 1;
342}
343
344static char * __initdata root_fs_names;
345static int __init fs_names_setup(char *str)
346{
347 root_fs_names = str;
348 return 1;
349}
350
351static unsigned int __initdata root_delay;
352static int __init root_delay_setup(char *str)
353{
354 root_delay = simple_strtoul(str, NULL, 0);
355 return 1;
356}
357
358__setup("rootflags=", root_data_setup);
359__setup("rootfstype=", fs_names_setup);
360__setup("rootdelay=", root_delay_setup);
361
362static void __init get_fs_names(char *page)
363{
364 char *s = page;
365
366 if (root_fs_names) {
367 strcpy(page, root_fs_names);
368 while (*s++) {
369 if (s[-1] == ',')
370 s[-1] = '\0';
371 }
372 } else {
373 int len = get_filesystem_list(page);
374 char *p, *next;
375
376 page[len] = '\0';
377 for (p = page-1; p; p = next) {
378 next = strchr(++p, '\n');
379 if (*p++ != '\t')
380 continue;
381 while ((*s++ = *p++) != '\n')
382 ;
383 s[-1] = '\0';
384 }
385 }
386 *s = '\0';
387}
388
389static int __init do_mount_root(const char *name, const char *fs,
390 const int flags, const void *data)
391{
392 struct super_block *s;
393 struct page *p = NULL;
394 char *data_page = NULL;
395 int ret;
396
397 if (data) {
398 /* init_mount() requires a full page as fifth argument */
399 p = alloc_page(GFP_KERNEL);
400 if (!p)
401 return -ENOMEM;
402 data_page = page_address(p);
403 /* zero-pad. init_mount() will make sure it's terminated */
404 strncpy(data_page, data, PAGE_SIZE);
405 }
406
407 ret = init_mount(name, "/root", fs, flags, data_page);
408 if (ret)
409 goto out;
410
411 init_chdir("/root");
412 s = current->fs->pwd.dentry->d_sb;
413 ROOT_DEV = s->s_dev;
414 printk(KERN_INFO
415 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
416 s->s_type->name,
417 sb_rdonly(s) ? " readonly" : "",
418 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
419
420out:
421 if (p)
422 put_page(p);
423 return ret;
424}
425
426void __init mount_block_root(char *name, int flags)
427{
428 struct page *page = alloc_page(GFP_KERNEL);
429 char *fs_names = page_address(page);
430 char *p;
431 char b[BDEVNAME_SIZE];
432
433 scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
434 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
435 get_fs_names(fs_names);
436retry:
437 for (p = fs_names; *p; p += strlen(p)+1) {
438 int err = do_mount_root(name, p, flags, root_mount_data);
439 switch (err) {
440 case 0:
441 goto out;
442 case -EACCES:
443 case -EINVAL:
444 continue;
445 }
446 /*
447 * Allow the user to distinguish between failed sys_open
448 * and bad superblock on root device.
449 * and give them a list of the available devices
450 */
451 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
452 root_device_name, b, err);
453 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
454
455 printk_all_partitions();
456#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
457 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
458 "explicit textual name for \"root=\" boot option.\n");
459#endif
460 panic("VFS: Unable to mount root fs on %s", b);
461 }
462 if (!(flags & SB_RDONLY)) {
463 flags |= SB_RDONLY;
464 goto retry;
465 }
466
467 printk("List of all partitions:\n");
468 printk_all_partitions();
469 printk("No filesystem could mount root, tried: ");
470 for (p = fs_names; *p; p += strlen(p)+1)
471 printk(" %s", p);
472 printk("\n");
473 panic("VFS: Unable to mount root fs on %s", b);
474out:
475 put_page(page);
476}
477
478#ifdef CONFIG_ROOT_NFS
479
480#define NFSROOT_TIMEOUT_MIN 5
481#define NFSROOT_TIMEOUT_MAX 30
482#define NFSROOT_RETRY_MAX 5
483
484static int __init mount_nfs_root(void)
485{
486 char *root_dev, *root_data;
487 unsigned int timeout;
488 int try, err;
489
490 err = nfs_root_data(&root_dev, &root_data);
491 if (err != 0)
492 return 0;
493
494 /*
495 * The server or network may not be ready, so try several
496 * times. Stop after a few tries in case the client wants
497 * to fall back to other boot methods.
498 */
499 timeout = NFSROOT_TIMEOUT_MIN;
500 for (try = 1; ; try++) {
501 err = do_mount_root(root_dev, "nfs",
502 root_mountflags, root_data);
503 if (err == 0)
504 return 1;
505 if (try > NFSROOT_RETRY_MAX)
506 break;
507
508 /* Wait, in case the server refused us immediately */
509 ssleep(timeout);
510 timeout <<= 1;
511 if (timeout > NFSROOT_TIMEOUT_MAX)
512 timeout = NFSROOT_TIMEOUT_MAX;
513 }
514 return 0;
515}
516#endif
517
518#ifdef CONFIG_CIFS_ROOT
519
520extern int cifs_root_data(char **dev, char **opts);
521
522#define CIFSROOT_TIMEOUT_MIN 5
523#define CIFSROOT_TIMEOUT_MAX 30
524#define CIFSROOT_RETRY_MAX 5
525
526static int __init mount_cifs_root(void)
527{
528 char *root_dev, *root_data;
529 unsigned int timeout;
530 int try, err;
531
532 err = cifs_root_data(&root_dev, &root_data);
533 if (err != 0)
534 return 0;
535
536 timeout = CIFSROOT_TIMEOUT_MIN;
537 for (try = 1; ; try++) {
538 err = do_mount_root(root_dev, "cifs", root_mountflags,
539 root_data);
540 if (err == 0)
541 return 1;
542 if (try > CIFSROOT_RETRY_MAX)
543 break;
544
545 ssleep(timeout);
546 timeout <<= 1;
547 if (timeout > CIFSROOT_TIMEOUT_MAX)
548 timeout = CIFSROOT_TIMEOUT_MAX;
549 }
550 return 0;
551}
552#endif
553
554void __init mount_root(void)
555{
556#ifdef CONFIG_ROOT_NFS
557 if (ROOT_DEV == Root_NFS) {
558 if (!mount_nfs_root())
559 printk(KERN_ERR "VFS: Unable to mount root fs via NFS.\n");
560 return;
561 }
562#endif
563#ifdef CONFIG_CIFS_ROOT
564 if (ROOT_DEV == Root_CIFS) {
565 if (!mount_cifs_root())
566 printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n");
567 return;
568 }
569#endif
570#ifdef CONFIG_BLOCK
571 {
572 int err = create_dev("/dev/root", ROOT_DEV);
573
574 if (err < 0)
575 pr_emerg("Failed to create /dev/root: %d\n", err);
576 mount_block_root("/dev/root", root_mountflags);
577 }
578#endif
579}
580
581/*
582 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
583 */
584void __init prepare_namespace(void)
585{
586 if (root_delay) {
587 printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
588 root_delay);
589 ssleep(root_delay);
590 }
591
592 /*
593 * wait for the known devices to complete their probing
594 *
595 * Note: this is a potential source of long boot delays.
596 * For example, it is not atypical to wait 5 seconds here
597 * for the touchpad of a laptop to initialize.
598 */
599 wait_for_device_probe();
600
601 md_run_setup();
602
603 if (saved_root_name[0]) {
604 root_device_name = saved_root_name;
605 if (!strncmp(root_device_name, "mtd", 3) ||
606 !strncmp(root_device_name, "ubi", 3)) {
607 mount_block_root(root_device_name, root_mountflags);
608 goto out;
609 }
610 ROOT_DEV = name_to_dev_t(root_device_name);
611 if (strncmp(root_device_name, "/dev/", 5) == 0)
612 root_device_name += 5;
613 }
614
615 if (initrd_load())
616 goto out;
617
618 /* wait for any asynchronous scanning to complete */
619 if ((ROOT_DEV == 0) && root_wait) {
620 printk(KERN_INFO "Waiting for root device %s...\n",
621 saved_root_name);
622 while (driver_probe_done() != 0 ||
623 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
624 msleep(5);
625 async_synchronize_full();
626 }
627
628 mount_root();
629out:
630 devtmpfs_mount();
631 init_mount(".", "/", NULL, MS_MOVE, NULL);
632 init_chroot(".");
633}
634
635static bool is_tmpfs;
636static int rootfs_init_fs_context(struct fs_context *fc)
637{
638 if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
639 return shmem_init_fs_context(fc);
640
641 return ramfs_init_fs_context(fc);
642}
643
644struct file_system_type rootfs_fs_type = {
645 .name = "rootfs",
646 .init_fs_context = rootfs_init_fs_context,
647 .kill_sb = kill_litter_super,
648};
649
650void __init init_rootfs(void)
651{
652 if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
653 (!root_fs_names || strstr(root_fs_names, "tmpfs")))
654 is_tmpfs = true;
655}