blob: 0f6e1d985a3b2851c662337c1671b57cc4270f0a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#include <linux/module.h>
2#include <linux/sched.h>
3#include <linux/ctype.h>
4#include <linux/fd.h>
5#include <linux/tty.h>
6#include <linux/suspend.h>
7#include <linux/root_dev.h>
8#include <linux/security.h>
9#include <linux/delay.h>
Dave Gilbertdd2a3452007-05-09 02:33:24 -070010#include <linux/genhd.h>
Andrew Mortond53d9f12005-07-12 13:58:07 -070011#include <linux/mount.h>
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -070012#include <linux/device.h>
Adrian Bunk46595392007-05-08 00:24:47 -070013#include <linux/init.h>
Adrian Bunk011e3fc2008-02-06 01:36:47 -080014#include <linux/fs.h>
Adrian Bunk82c82532008-07-25 01:45:29 -070015#include <linux/initrd.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080016#include <linux/async.h>
Al Viro5ad4e532009-03-29 19:50:06 -040017#include <linux/fs_struct.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
20#include <linux/nfs_fs.h>
21#include <linux/nfs_fs_sb.h>
22#include <linux/nfs_mount.h>
23
24#include "do_mounts.h"
25
Linus Torvalds1da177e2005-04-16 15:20:36 -070026int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
27
Theodore Ts'o9b04c992006-03-24 03:15:10 -080028int root_mountflags = MS_RDONLY | MS_SILENT;
Adrian Bunkf56f6d302008-07-25 19:46:25 -070029static char * __initdata root_device_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -070030static char __initdata saved_root_name[64];
Will Drewry79975f12011-11-02 13:38:59 -070031static int root_wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Linus Torvalds1da177e2005-04-16 15:20:36 -070033dev_t ROOT_DEV;
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035static int __init load_ramdisk(char *str)
36{
37 rd_doload = simple_strtol(str,NULL,0) & 3;
38 return 1;
39}
40__setup("load_ramdisk=", load_ramdisk);
41
42static int __init readonly(char *str)
43{
44 if (*str)
45 return 0;
46 root_mountflags |= MS_RDONLY;
47 return 1;
48}
49
50static int __init readwrite(char *str)
51{
52 if (*str)
53 return 0;
54 root_mountflags &= ~MS_RDONLY;
55 return 1;
56}
57
58__setup("ro", readonly);
59__setup("rw", readwrite);
60
Jens Axboe6d0aed72010-09-17 10:00:46 +020061#ifdef CONFIG_BLOCK
Will Drewryb5af9212010-08-31 15:47:07 -050062/**
63 * match_dev_by_uuid - callback for finding a partition using its uuid
64 * @dev: device passed in by the caller
65 * @data: opaque pointer to a 36 byte char array with a UUID
66 *
67 * Returns 1 if the device matches, and 0 otherwise.
68 */
Jens Axboe38b6f452010-09-16 08:33:54 +020069static int match_dev_by_uuid(struct device *dev, void *data)
Will Drewryb5af9212010-08-31 15:47:07 -050070{
71 u8 *uuid = data;
72 struct hd_struct *part = dev_to_part(dev);
73
74 if (!part->info)
75 goto no_match;
76
77 if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid)))
78 goto no_match;
79
80 return 1;
81no_match:
82 return 0;
83}
84
85
86/**
87 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
Will Drewry79975f12011-11-02 13:38:59 -070088 * @uuid: min 36 byte char array containing a hex ascii UUID
Will Drewryb5af9212010-08-31 15:47:07 -050089 *
90 * The function will return the first partition which contains a matching
91 * UUID value in its partition_meta_info struct. This does not search
92 * by filesystem UUIDs.
93 *
Will Drewry79975f12011-11-02 13:38:59 -070094 * If @uuid is followed by a "/PARTNROFF=%d", then the number will be
95 * extracted and used as an offset from the partition identified by the UUID.
96 *
Will Drewryb5af9212010-08-31 15:47:07 -050097 * Returns the matching dev_t on success or 0 on failure.
98 */
Jan Beulicha1cf11d2011-01-03 15:07:02 +000099static dev_t devt_from_partuuid(char *uuid_str)
Will Drewryb5af9212010-08-31 15:47:07 -0500100{
101 dev_t res = 0;
102 struct device *dev = NULL;
103 u8 uuid[16];
Will Drewry79975f12011-11-02 13:38:59 -0700104 struct gendisk *disk;
105 struct hd_struct *part;
106 int offset = 0;
107
108 if (strlen(uuid_str) < 36)
109 goto done;
110
111 /* Check for optional partition number offset attributes. */
112 if (uuid_str[36]) {
113 char c = 0;
114 /* Explicitly fail on poor PARTUUID syntax. */
115 if (sscanf(&uuid_str[36],
116 "/PARTNROFF=%d%c", &offset, &c) != 1) {
117 printk(KERN_ERR "VFS: PARTUUID= is invalid.\n"
118 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
119 if (root_wait)
120 printk(KERN_ERR
121 "Disabling rootwait; root= is invalid.\n");
122 root_wait = 0;
123 goto done;
124 }
125 }
Will Drewryb5af9212010-08-31 15:47:07 -0500126
127 /* Pack the requested UUID in the expected format. */
128 part_pack_uuid(uuid_str, uuid);
129
130 dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
131 if (!dev)
132 goto done;
133
134 res = dev->devt;
Will Drewryb5af9212010-08-31 15:47:07 -0500135
Will Drewry79975f12011-11-02 13:38:59 -0700136 /* Attempt to find the partition by offset. */
137 if (!offset)
138 goto no_offset;
139
140 res = 0;
141 disk = part_to_disk(dev_to_part(dev));
142 part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
143 if (part) {
144 res = part_devt(part);
145 put_device(part_to_dev(part));
146 }
147
148no_offset:
149 put_device(dev);
Will Drewryb5af9212010-08-31 15:47:07 -0500150done:
151 return res;
152}
Jens Axboe6d0aed72010-09-17 10:00:46 +0200153#endif
Will Drewryb5af9212010-08-31 15:47:07 -0500154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155/*
156 * Convert a name into device number. We accept the following variants:
157 *
158 * 1) device number in hexadecimal represents itself
159 * 2) /dev/nfs represents Root_NFS (0xff)
160 * 3) /dev/<disk_name> represents the device number of disk
161 * 4) /dev/<disk_name><decimal> represents the device number
162 * of partition - device number of disk plus the partition number
163 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
164 * used when disk name of partitioned disk ends on a digit.
Will Drewryb5af9212010-08-31 15:47:07 -0500165 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
166 * unique id of a partition if the partition table provides it.
Will Drewry79975f12011-11-02 13:38:59 -0700167 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
168 * a partition with a known unique id.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 *
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200170 * If name doesn't have fall into the categories above, we return (0,0).
171 * block_class is used to check if something is a disk name. If the disk
172 * name contains slashes, the device name has them replaced with
173 * bangs.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 */
175
176dev_t name_to_dev_t(char *name)
177{
178 char s[32];
179 char *p;
180 dev_t res = 0;
Kay Sievers30f2f0e2008-05-06 22:31:33 +0200181 int part;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
Jens Axboe6d0aed72010-09-17 10:00:46 +0200183#ifdef CONFIG_BLOCK
Will Drewryb5af9212010-08-31 15:47:07 -0500184 if (strncmp(name, "PARTUUID=", 9) == 0) {
185 name += 9;
Will Drewryb5af9212010-08-31 15:47:07 -0500186 res = devt_from_partuuid(name);
187 if (!res)
188 goto fail;
189 goto done;
190 }
Jens Axboe6d0aed72010-09-17 10:00:46 +0200191#endif
Will Drewryb5af9212010-08-31 15:47:07 -0500192
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 if (strncmp(name, "/dev/", 5) != 0) {
194 unsigned maj, min;
195
196 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
197 res = MKDEV(maj, min);
198 if (maj != MAJOR(res) || min != MINOR(res))
199 goto fail;
200 } else {
201 res = new_decode_dev(simple_strtoul(name, &p, 16));
202 if (*p)
203 goto fail;
204 }
205 goto done;
206 }
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200207
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 name += 5;
209 res = Root_NFS;
210 if (strcmp(name, "nfs") == 0)
211 goto done;
212 res = Root_RAM0;
213 if (strcmp(name, "ram") == 0)
214 goto done;
215
216 if (strlen(name) > 31)
217 goto fail;
218 strcpy(s, name);
219 for (p = s; *p; p++)
220 if (*p == '/')
221 *p = '!';
Kay Sievers30f2f0e2008-05-06 22:31:33 +0200222 res = blk_lookup_devt(s, 0);
223 if (res)
224 goto done;
225
226 /*
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300227 * try non-existent, but valid partition, which may only exist
Kay Sievers30f2f0e2008-05-06 22:31:33 +0200228 * after revalidating the disk, like partitioned md devices
229 */
230 while (p > s && isdigit(p[-1]))
231 p--;
232 if (p == s || !*p || *p == '0')
233 goto fail;
234
235 /* try disk name without <part number> */
236 part = simple_strtoul(p, NULL, 10);
237 *p = '\0';
238 res = blk_lookup_devt(s, part);
239 if (res)
240 goto done;
241
242 /* try disk name without p<part number> */
243 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
244 goto fail;
245 p[-1] = '\0';
246 res = blk_lookup_devt(s, part);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 if (res)
248 goto done;
249
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250fail:
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200251 return 0;
252done:
253 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254}
255
256static int __init root_dev_setup(char *line)
257{
258 strlcpy(saved_root_name, line, sizeof(saved_root_name));
259 return 1;
260}
261
262__setup("root=", root_dev_setup);
263
Pierre Ossmancc1ed752007-07-15 23:40:35 -0700264static int __init rootwait_setup(char *str)
265{
266 if (*str)
267 return 0;
268 root_wait = 1;
269 return 1;
270}
271
272__setup("rootwait", rootwait_setup);
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274static char * __initdata root_mount_data;
275static int __init root_data_setup(char *str)
276{
277 root_mount_data = str;
278 return 1;
279}
280
281static char * __initdata root_fs_names;
282static int __init fs_names_setup(char *str)
283{
284 root_fs_names = str;
285 return 1;
286}
287
288static unsigned int __initdata root_delay;
289static int __init root_delay_setup(char *str)
290{
291 root_delay = simple_strtoul(str, NULL, 0);
292 return 1;
293}
294
295__setup("rootflags=", root_data_setup);
296__setup("rootfstype=", fs_names_setup);
297__setup("rootdelay=", root_delay_setup);
298
299static void __init get_fs_names(char *page)
300{
301 char *s = page;
302
303 if (root_fs_names) {
304 strcpy(page, root_fs_names);
305 while (*s++) {
306 if (s[-1] == ',')
307 s[-1] = '\0';
308 }
309 } else {
310 int len = get_filesystem_list(page);
311 char *p, *next;
312
313 page[len] = '\0';
314 for (p = page-1; p; p = next) {
315 next = strchr(++p, '\n');
316 if (*p++ != '\t')
317 continue;
318 while ((*s++ = *p++) != '\n')
319 ;
320 s[-1] = '\0';
321 }
322 }
323 *s = '\0';
324}
325
326static int __init do_mount_root(char *name, char *fs, int flags, void *data)
327{
328 int err = sys_mount(name, "/root", fs, flags, data);
329 if (err)
330 return err;
331
Namhyung Kim562f5e62010-10-26 14:22:42 -0700332 sys_chdir((const char __user __force *)"/root");
Jan Blunck6ac08c32008-02-14 19:34:38 -0800333 ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
Mandeep Singh Baines80cdc6d2011-03-22 16:33:54 -0700334 printk(KERN_INFO
335 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
Jan Blunck6ac08c32008-02-14 19:34:38 -0800336 current->fs->pwd.mnt->mnt_sb->s_type->name,
337 current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
Marton Balintbca10332009-01-06 14:40:43 -0800338 " readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 return 0;
340}
341
342void __init mount_block_root(char *name, int flags)
343{
Vegard Nossum3b5c7602009-05-16 11:26:20 +0200344 char *fs_names = __getname_gfp(GFP_KERNEL
345 | __GFP_NOTRACK_FALSE_POSITIVE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 char *p;
David Howells93614012006-09-30 20:45:40 +0200347#ifdef CONFIG_BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 char b[BDEVNAME_SIZE];
David Howells93614012006-09-30 20:45:40 +0200349#else
350 const char *b = name;
351#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
353 get_fs_names(fs_names);
354retry:
355 for (p = fs_names; *p; p += strlen(p)+1) {
356 int err = do_mount_root(name, p, flags, root_mount_data);
357 switch (err) {
358 case 0:
359 goto out;
360 case -EACCES:
361 flags |= MS_RDONLY;
362 goto retry;
363 case -EINVAL:
364 continue;
365 }
366 /*
367 * Allow the user to distinguish between failed sys_open
368 * and bad superblock on root device.
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700369 * and give them a list of the available devices
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 */
David Howells93614012006-09-30 20:45:40 +0200371#ifdef CONFIG_BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 __bdevname(ROOT_DEV, b);
David Howells93614012006-09-30 20:45:40 +0200373#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 printk("VFS: Cannot open root device \"%s\" or %s\n",
375 root_device_name, b);
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700376 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700378 printk_all_partitions();
Tejun Heo55dc7db2008-09-01 13:44:35 +0200379#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
380 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
381 "explicit textual name for \"root=\" boot option.\n");
382#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 panic("VFS: Unable to mount root fs on %s", b);
384 }
Andy Whitcroftbe6e028b2006-05-15 09:44:29 -0700385
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700386 printk("List of all partitions:\n");
387 printk_all_partitions();
Andy Whitcroftbe6e028b2006-05-15 09:44:29 -0700388 printk("No filesystem could mount root, tried: ");
389 for (p = fs_names; *p; p += strlen(p)+1)
390 printk(" %s", p);
391 printk("\n");
David Howells93614012006-09-30 20:45:40 +0200392#ifdef CONFIG_BLOCK
393 __bdevname(ROOT_DEV, b);
394#endif
395 panic("VFS: Unable to mount root fs on %s", b);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396out:
397 putname(fs_names);
398}
399
400#ifdef CONFIG_ROOT_NFS
401static int __init mount_nfs_root(void)
402{
Chuck Lever56463e52010-09-17 10:54:37 -0400403 char *root_dev, *root_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
Chuck Lever56463e52010-09-17 10:54:37 -0400405 if (nfs_root_data(&root_dev, &root_data) != 0)
406 return 0;
407 if (do_mount_root(root_dev, "nfs", root_mountflags, root_data) != 0)
408 return 0;
409 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410}
411#endif
412
413#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
414void __init change_floppy(char *fmt, ...)
415{
416 struct termios termios;
417 char buf[80];
418 char c;
419 int fd;
420 va_list args;
421 va_start(args, fmt);
422 vsprintf(buf, fmt, args);
423 va_end(args);
424 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
425 if (fd >= 0) {
426 sys_ioctl(fd, FDEJECT, 0);
427 sys_close(fd);
428 }
429 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
430 fd = sys_open("/dev/console", O_RDWR, 0);
431 if (fd >= 0) {
432 sys_ioctl(fd, TCGETS, (long)&termios);
433 termios.c_lflag &= ~ICANON;
434 sys_ioctl(fd, TCSETSF, (long)&termios);
435 sys_read(fd, &c, 1);
436 termios.c_lflag |= ICANON;
437 sys_ioctl(fd, TCSETSF, (long)&termios);
438 sys_close(fd);
439 }
440}
441#endif
442
443void __init mount_root(void)
444{
445#ifdef CONFIG_ROOT_NFS
446 if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
447 if (mount_nfs_root())
448 return;
449
450 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
451 ROOT_DEV = Root_FD0;
452 }
453#endif
454#ifdef CONFIG_BLK_DEV_FD
455 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
456 /* rd_doload is 2 for a dual initrd/ramload setup */
457 if (rd_doload==2) {
458 if (rd_load_disk(1)) {
459 ROOT_DEV = Root_RAM1;
460 root_device_name = NULL;
461 }
462 } else
463 change_floppy("root floppy");
464 }
465#endif
David Howells93614012006-09-30 20:45:40 +0200466#ifdef CONFIG_BLOCK
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -0700467 create_dev("/dev/root", ROOT_DEV);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 mount_block_root("/dev/root", root_mountflags);
David Howells93614012006-09-30 20:45:40 +0200469#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470}
471
472/*
473 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
474 */
475void __init prepare_namespace(void)
476{
477 int is_floppy;
478
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 if (root_delay) {
480 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
481 root_delay);
482 ssleep(root_delay);
483 }
484
Arjan van de Ven216773a2009-02-14 01:59:06 +0100485 /*
486 * wait for the known devices to complete their probing
487 *
488 * Note: this is a potential source of long boot delays.
489 * For example, it is not atypical to wait 5 seconds here
490 * for the touchpad of a laptop to initialize.
491 */
492 wait_for_device_probe();
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700493
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 md_run_setup();
495
496 if (saved_root_name[0]) {
497 root_device_name = saved_root_name;
Adrian Hunter2d62f482008-01-31 17:25:00 +0200498 if (!strncmp(root_device_name, "mtd", 3) ||
499 !strncmp(root_device_name, "ubi", 3)) {
Joern Engele9482b42006-05-30 14:25:46 +0200500 mount_block_root(root_device_name, root_mountflags);
501 goto out;
502 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 ROOT_DEV = name_to_dev_t(root_device_name);
504 if (strncmp(root_device_name, "/dev/", 5) == 0)
505 root_device_name += 5;
506 }
507
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 if (initrd_load())
509 goto out;
510
Pierre Ossmancc1ed752007-07-15 23:40:35 -0700511 /* wait for any asynchronous scanning to complete */
512 if ((ROOT_DEV == 0) && root_wait) {
513 printk(KERN_INFO "Waiting for root device %s...\n",
514 saved_root_name);
515 while (driver_probe_done() != 0 ||
516 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
517 msleep(100);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100518 async_synchronize_full();
Pierre Ossmancc1ed752007-07-15 23:40:35 -0700519 }
520
521 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
522
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 if (is_floppy && rd_doload && rd_load_disk(0))
524 ROOT_DEV = Root_RAM0;
525
526 mount_root();
527out:
Kay Sievers2b2af542009-04-30 15:23:42 +0200528 devtmpfs_mount("dev");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 sys_mount(".", "/", NULL, MS_MOVE, NULL);
Namhyung Kim562f5e62010-10-26 14:22:42 -0700530 sys_chroot((const char __user __force *)".");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531}