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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// 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 <uapi/linux/mount.h>
27
28#include "do_mounts.h"
29
30int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
31
32int root_mountflags = MS_RDONLY | MS_SILENT;
33static char * __initdata root_device_name;
34static char __initdata saved_root_name[64];
35static int root_wait;
36
37dev_t ROOT_DEV;
38
39static int __init load_ramdisk(char *str)
40{
41 rd_doload = simple_strtol(str,NULL,0) & 3;
42 return 1;
43}
44__setup("load_ramdisk=", load_ramdisk);
45
46static int __init readonly(char *str)
47{
48 if (*str)
49 return 0;
50 root_mountflags |= MS_RDONLY;
51 return 1;
52}
53
54static int __init readwrite(char *str)
55{
56 if (*str)
57 return 0;
58 root_mountflags &= ~MS_RDONLY;
59 return 1;
60}
61
62__setup("ro", readonly);
63__setup("rw", readwrite);
64
65#ifdef CONFIG_BLOCK
66struct uuidcmp {
67 const char *uuid;
68 int len;
69};
70
71/**
72 * match_dev_by_uuid - callback for finding a partition using its uuid
73 * @dev: device passed in by the caller
74 * @data: opaque pointer to the desired struct uuidcmp to match
75 *
76 * Returns 1 if the device matches, and 0 otherwise.
77 */
78static int match_dev_by_uuid(struct device *dev, const void *data)
79{
80 const struct uuidcmp *cmp = data;
81 struct hd_struct *part = dev_to_part(dev);
82
83 if (!part->info)
84 goto no_match;
85
86 if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len))
87 goto no_match;
88
89 return 1;
90no_match:
91 return 0;
92}
93
94
95/**
96 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
97 * @uuid_str: char array containing ascii UUID
98 *
99 * The function will return the first partition which contains a matching
100 * UUID value in its partition_meta_info struct. This does not search
101 * by filesystem UUIDs.
102 *
103 * If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be
104 * extracted and used as an offset from the partition identified by the UUID.
105 *
106 * Returns the matching dev_t on success or 0 on failure.
107 */
108static dev_t devt_from_partuuid(const char *uuid_str)
109{
110 dev_t res = 0;
111 struct uuidcmp cmp;
112 struct device *dev = NULL;
113 struct gendisk *disk;
114 struct hd_struct *part;
115 int offset = 0;
116 bool clear_root_wait = false;
117 char *slash;
118
119 cmp.uuid = uuid_str;
120
121 slash = strchr(uuid_str, '/');
122 /* Check for optional partition number offset attributes. */
123 if (slash) {
124 char c = 0;
125 /* Explicitly fail on poor PARTUUID syntax. */
126 if (sscanf(slash + 1,
127 "PARTNROFF=%d%c", &offset, &c) != 1) {
128 clear_root_wait = true;
129 goto done;
130 }
131 cmp.len = slash - uuid_str;
132 } else {
133 cmp.len = strlen(uuid_str);
134 }
135
136 if (!cmp.len) {
137 clear_root_wait = true;
138 goto done;
139 }
140
141 dev = class_find_device(&block_class, NULL, &cmp,
142 &match_dev_by_uuid);
143 if (!dev)
144 goto done;
145
146 res = dev->devt;
147
148 /* Attempt to find the partition by offset. */
149 if (!offset)
150 goto no_offset;
151
152 res = 0;
153 disk = part_to_disk(dev_to_part(dev));
154 part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
155 if (part) {
156 res = part_devt(part);
157 put_device(part_to_dev(part));
158 }
159
160no_offset:
161 put_device(dev);
162done:
163 if (clear_root_wait) {
164 pr_err("VFS: PARTUUID= is invalid.\n"
165 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
166 if (root_wait)
167 pr_err("Disabling rootwait; root= is invalid.\n");
168 root_wait = 0;
169 }
170 return res;
171}
172
173/**
174 * match_dev_by_label - callback for finding a partition using its label
175 * @dev: device passed in by the caller
176 * @data: opaque pointer to the label to match
177 *
178 * Returns 1 if the device matches, and 0 otherwise.
179 */
180static int match_dev_by_label(struct device *dev, const void *data)
181{
182 const char *label = data;
183 struct hd_struct *part = dev_to_part(dev);
184
185 if (part->info && !strcmp(label, part->info->volname))
186 return 1;
187
188 return 0;
189}
190#endif
191
192/*
193 * Convert a name into device number. We accept the following variants:
194 *
195 * 1) <hex_major><hex_minor> device number in hexadecimal represents itself
196 * no leading 0x, for example b302.
197 * 2) /dev/nfs represents Root_NFS (0xff)
198 * 3) /dev/<disk_name> represents the device number of disk
199 * 4) /dev/<disk_name><decimal> represents the device number
200 * of partition - device number of disk plus the partition number
201 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
202 * used when disk name of partitioned disk ends on a digit.
203 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
204 * unique id of a partition if the partition table provides it.
205 * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
206 * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
207 * filled hex representation of the 32-bit "NT disk signature", and PP
208 * is a zero-filled hex representation of the 1-based partition number.
209 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
210 * a partition with a known unique id.
211 * 8) <major>:<minor> major and minor number of the device separated by
212 * a colon.
213 * 9) PARTLABEL=<name> with name being the GPT partition label.
214 * MSDOS partitions do not support labels!
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_RAM0;
272 if (strcmp(name, "ram") == 0)
273 goto done;
274
275 if (strlen(name) > 31)
276 goto fail;
277 strcpy(s, name);
278 for (p = s; *p; p++)
279 if (*p == '/')
280 *p = '!';
281 res = blk_lookup_devt(s, 0);
282 if (res)
283 goto done;
284
285 /*
286 * try non-existent, but valid partition, which may only exist
287 * after revalidating the disk, like partitioned md devices
288 */
289 while (p > s && isdigit(p[-1]))
290 p--;
291 if (p == s || !*p || *p == '0')
292 goto fail;
293
294 /* try disk name without <part number> */
295 part = simple_strtoul(p, NULL, 10);
296 *p = '\0';
297 res = blk_lookup_devt(s, part);
298 if (res)
299 goto done;
300
301 /* try disk name without p<part number> */
302 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
303 goto fail;
304 p[-1] = '\0';
305 res = blk_lookup_devt(s, part);
306 if (res)
307 goto done;
308
309fail:
310 return 0;
311done:
312 return res;
313}
314EXPORT_SYMBOL_GPL(name_to_dev_t);
315
316static int __init root_dev_setup(char *line)
317{
318 strlcpy(saved_root_name, line, sizeof(saved_root_name));
319 return 1;
320}
321
322__setup("root=", root_dev_setup);
323
324static int __init rootwait_setup(char *str)
325{
326 if (*str)
327 return 0;
328 root_wait = 1;
329 return 1;
330}
331
332__setup("rootwait", rootwait_setup);
333
334static char * __initdata root_mount_data;
335static int __init root_data_setup(char *str)
336{
337 root_mount_data = str;
338 return 1;
339}
340
341static char * __initdata root_fs_names;
342static int __init fs_names_setup(char *str)
343{
344 root_fs_names = str;
345 return 1;
346}
347
348static unsigned int __initdata root_delay;
349static int __init root_delay_setup(char *str)
350{
351 root_delay = simple_strtoul(str, NULL, 0);
352 return 1;
353}
354
355__setup("rootflags=", root_data_setup);
356__setup("rootfstype=", fs_names_setup);
357__setup("rootdelay=", root_delay_setup);
358
359static void __init get_fs_names(char *page)
360{
361 char *s = page;
362
363 if (root_fs_names) {
364 strcpy(page, root_fs_names);
365 while (*s++) {
366 if (s[-1] == ',')
367 s[-1] = '\0';
368 }
369 } else {
370 int len = get_filesystem_list(page);
371 char *p, *next;
372
373 page[len] = '\0';
374 for (p = page-1; p; p = next) {
375 next = strchr(++p, '\n');
376 if (*p++ != '\t')
377 continue;
378 while ((*s++ = *p++) != '\n')
379 ;
380 s[-1] = '\0';
381 }
382 }
383 *s = '\0';
384}
385
386static int __init do_mount_root(char *name, char *fs, int flags, void *data)
387{
388 struct super_block *s;
389 int err = ksys_mount(name, "/root", fs, flags, data);
390 if (err)
391 return err;
392
393 ksys_chdir("/root");
394 s = current->fs->pwd.dentry->d_sb;
395 ROOT_DEV = s->s_dev;
396 printk(KERN_INFO
397 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
398 s->s_type->name,
399 sb_rdonly(s) ? " readonly" : "",
400 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
401 return 0;
402}
403
404void __init mount_block_root(char *name, int flags)
405{
406 struct page *page = alloc_page(GFP_KERNEL);
407 char *fs_names = page_address(page);
408 char *p;
409#ifdef CONFIG_BLOCK
410 char b[BDEVNAME_SIZE];
411#else
412 const char *b = name;
413#endif
414
415 get_fs_names(fs_names);
416retry:
417 for (p = fs_names; *p; p += strlen(p)+1) {
418 int err = do_mount_root(name, p, flags, root_mount_data);
419 switch (err) {
420 case 0:
421 goto out;
422 case -EACCES:
423 case -EINVAL:
424 continue;
425 }
426 /*
427 * Allow the user to distinguish between failed sys_open
428 * and bad superblock on root device.
429 * and give them a list of the available devices
430 */
431#ifdef CONFIG_BLOCK
432 __bdevname(ROOT_DEV, b);
433#endif
434 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
435 root_device_name, b, err);
436 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
437
438 printk_all_partitions();
439#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
440 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
441 "explicit textual name for \"root=\" boot option.\n");
442#endif
443 panic("VFS: Unable to mount root fs on %s", b);
444 }
445 if (!(flags & SB_RDONLY)) {
446 flags |= SB_RDONLY;
447 goto retry;
448 }
449
450 printk("List of all partitions:\n");
451 printk_all_partitions();
452 printk("No filesystem could mount root, tried: ");
453 for (p = fs_names; *p; p += strlen(p)+1)
454 printk(" %s", p);
455 printk("\n");
456#ifdef CONFIG_BLOCK
457 __bdevname(ROOT_DEV, b);
458#endif
459 panic("VFS: Unable to mount root fs on %s", b);
460out:
461 put_page(page);
462}
463
464#ifdef CONFIG_ROOT_NFS
465
466#define NFSROOT_TIMEOUT_MIN 5
467#define NFSROOT_TIMEOUT_MAX 30
468#define NFSROOT_RETRY_MAX 5
469
470static int __init mount_nfs_root(void)
471{
472 char *root_dev, *root_data;
473 unsigned int timeout;
474 int try, err;
475
476 err = nfs_root_data(&root_dev, &root_data);
477 if (err != 0)
478 return 0;
479
480 /*
481 * The server or network may not be ready, so try several
482 * times. Stop after a few tries in case the client wants
483 * to fall back to other boot methods.
484 */
485 timeout = NFSROOT_TIMEOUT_MIN;
486 for (try = 1; ; try++) {
487 err = do_mount_root(root_dev, "nfs",
488 root_mountflags, root_data);
489 if (err == 0)
490 return 1;
491 if (try > NFSROOT_RETRY_MAX)
492 break;
493
494 /* Wait, in case the server refused us immediately */
495 ssleep(timeout);
496 timeout <<= 1;
497 if (timeout > NFSROOT_TIMEOUT_MAX)
498 timeout = NFSROOT_TIMEOUT_MAX;
499 }
500 return 0;
501}
502#endif
503
504#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
505void __init change_floppy(char *fmt, ...)
506{
507 struct termios termios;
508 char buf[80];
509 char c;
510 int fd;
511 va_list args;
512 va_start(args, fmt);
513 vsprintf(buf, fmt, args);
514 va_end(args);
515 fd = ksys_open("/dev/root", O_RDWR | O_NDELAY, 0);
516 if (fd >= 0) {
517 ksys_ioctl(fd, FDEJECT, 0);
518 ksys_close(fd);
519 }
520 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
521 fd = ksys_open("/dev/console", O_RDWR, 0);
522 if (fd >= 0) {
523 ksys_ioctl(fd, TCGETS, (long)&termios);
524 termios.c_lflag &= ~ICANON;
525 ksys_ioctl(fd, TCSETSF, (long)&termios);
526 ksys_read(fd, &c, 1);
527 termios.c_lflag |= ICANON;
528 ksys_ioctl(fd, TCSETSF, (long)&termios);
529 ksys_close(fd);
530 }
531}
532#endif
533
534void __init mount_root(void)
535{
536#ifdef CONFIG_ROOT_NFS
537 if (ROOT_DEV == Root_NFS) {
538 if (mount_nfs_root())
539 return;
540
541 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
542 ROOT_DEV = Root_FD0;
543 }
544#endif
545#ifdef CONFIG_BLK_DEV_FD
546 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
547 /* rd_doload is 2 for a dual initrd/ramload setup */
548 if (rd_doload==2) {
549 if (rd_load_disk(1)) {
550 ROOT_DEV = Root_RAM1;
551 root_device_name = NULL;
552 }
553 } else
554 change_floppy("root floppy");
555 }
556#endif
557#ifdef CONFIG_BLOCK
558 {
559 int err = create_dev("/dev/root", ROOT_DEV);
560
561 if (err < 0)
562 pr_emerg("Failed to create /dev/root: %d\n", err);
563 mount_block_root("/dev/root", root_mountflags);
564 }
565#endif
566}
567
568/*
569 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
570 */
571void __init prepare_namespace(void)
572{
573 int is_floppy;
574
575 if (root_delay) {
576 printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
577 root_delay);
578 ssleep(root_delay);
579 }
580
581 /*
582 * wait for the known devices to complete their probing
583 *
584 * Note: this is a potential source of long boot delays.
585 * For example, it is not atypical to wait 5 seconds here
586 * for the touchpad of a laptop to initialize.
587 */
588 wait_for_device_probe();
589
590 md_run_setup();
591
592 if (saved_root_name[0]) {
593 root_device_name = saved_root_name;
594 if (!strncmp(root_device_name, "mtd", 3) ||
595 !strncmp(root_device_name, "ubi", 3)) {
596 mount_block_root(root_device_name, root_mountflags);
597 goto out;
598 }
599 ROOT_DEV = name_to_dev_t(root_device_name);
600 if (strncmp(root_device_name, "/dev/", 5) == 0)
601 root_device_name += 5;
602 }
603
604 if (initrd_load())
605 goto out;
606
607 /* wait for any asynchronous scanning to complete */
608 if ((ROOT_DEV == 0) && root_wait) {
609 printk(KERN_INFO "Waiting for root device %s...\n",
610 saved_root_name);
611 while (driver_probe_done() != 0 ||
612 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
613 msleep(5);
614 async_synchronize_full();
615 }
616
617 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
618
619 if (is_floppy && rd_doload && rd_load_disk(0))
620 ROOT_DEV = Root_RAM0;
621
622 mount_root();
623out:
624 devtmpfs_mount("dev");
625 ksys_mount(".", "/", NULL, MS_MOVE, NULL);
626 ksys_chroot(".");
627}
628
629static bool is_tmpfs;
630static int rootfs_init_fs_context(struct fs_context *fc)
631{
632 if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
633 return shmem_init_fs_context(fc);
634
635 return ramfs_init_fs_context(fc);
636}
637
638struct file_system_type rootfs_fs_type = {
639 .name = "rootfs",
640 .init_fs_context = rootfs_init_fs_context,
641 .kill_sb = kill_litter_super,
642};
643
644void __init init_rootfs(void)
645{
646 if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
647 (!root_fs_names || strstr(root_fs_names, "tmpfs")))
648 is_tmpfs = true;
649}