1 #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>
10 #include <linux/genhd.h>
11 #include <linux/mount.h>
12 #include <linux/device.h>
13 #include <linux/init.h>
14 #include <linux/fs.h>
15 #include <linux/initrd.h>
16 #include <linux/async.h>
17 #include <linux/fs_struct.h>
18 #include <linux/slab.h>
19
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
26 int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
27
28 int root_mountflags = MS_RDONLY | MS_SILENT;
29 static char * __initdata root_device_name;
30 static char __initdata saved_root_name[64];
31 static int __initdata root_wait;
32
33 dev_t ROOT_DEV;
34
load_ramdisk(char * str)35 static 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
readonly(char * str)42 static int __init readonly(char *str)
43 {
44 if (*str)
45 return 0;
46 root_mountflags |= MS_RDONLY;
47 return 1;
48 }
49
readwrite(char * str)50 static 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
61 #ifdef CONFIG_BLOCK
62 /**
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 */
match_dev_by_uuid(struct device * dev,void * data)69 static int match_dev_by_uuid(struct device *dev, void *data)
70 {
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;
81 no_match:
82 return 0;
83 }
84
85
86 /**
87 * devt_from_partuuid - looks up the dev_t of a partition by its UUID
88 * @uuid: 36 byte char array containing a hex ascii UUID
89 *
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 *
94 * Returns the matching dev_t on success or 0 on failure.
95 */
devt_from_partuuid(char * uuid_str)96 static dev_t devt_from_partuuid(char *uuid_str)
97 {
98 dev_t res = 0;
99 struct device *dev = NULL;
100 u8 uuid[16];
101
102 /* Pack the requested UUID in the expected format. */
103 part_pack_uuid(uuid_str, uuid);
104
105 dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
106 if (!dev)
107 goto done;
108
109 res = dev->devt;
110 put_device(dev);
111
112 done:
113 return res;
114 }
115 #endif
116
117 /*
118 * Convert a name into device number. We accept the following variants:
119 *
120 * 1) device number in hexadecimal represents itself
121 * 2) /dev/nfs represents Root_NFS (0xff)
122 * 3) /dev/<disk_name> represents the device number of disk
123 * 4) /dev/<disk_name><decimal> represents the device number
124 * of partition - device number of disk plus the partition number
125 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
126 * used when disk name of partitioned disk ends on a digit.
127 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
128 * unique id of a partition if the partition table provides it.
129 *
130 * If name doesn't have fall into the categories above, we return (0,0).
131 * block_class is used to check if something is a disk name. If the disk
132 * name contains slashes, the device name has them replaced with
133 * bangs.
134 */
135
name_to_dev_t(char * name)136 dev_t name_to_dev_t(char *name)
137 {
138 char s[32];
139 char *p;
140 dev_t res = 0;
141 int part;
142
143 #ifdef CONFIG_BLOCK
144 if (strncmp(name, "PARTUUID=", 9) == 0) {
145 name += 9;
146 if (strlen(name) != 36)
147 goto fail;
148 res = devt_from_partuuid(name);
149 if (!res)
150 goto fail;
151 goto done;
152 }
153 #endif
154
155 if (strncmp(name, "/dev/", 5) != 0) {
156 unsigned maj, min;
157
158 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
159 res = MKDEV(maj, min);
160 if (maj != MAJOR(res) || min != MINOR(res))
161 goto fail;
162 } else {
163 res = new_decode_dev(simple_strtoul(name, &p, 16));
164 if (*p)
165 goto fail;
166 }
167 goto done;
168 }
169
170 name += 5;
171 res = Root_NFS;
172 if (strcmp(name, "nfs") == 0)
173 goto done;
174 res = Root_RAM0;
175 if (strcmp(name, "ram") == 0)
176 goto done;
177
178 if (strlen(name) > 31)
179 goto fail;
180 strcpy(s, name);
181 for (p = s; *p; p++)
182 if (*p == '/')
183 *p = '!';
184 res = blk_lookup_devt(s, 0);
185 if (res)
186 goto done;
187
188 /*
189 * try non-existent, but valid partition, which may only exist
190 * after revalidating the disk, like partitioned md devices
191 */
192 while (p > s && isdigit(p[-1]))
193 p--;
194 if (p == s || !*p || *p == '0')
195 goto fail;
196
197 /* try disk name without <part number> */
198 part = simple_strtoul(p, NULL, 10);
199 *p = '\0';
200 res = blk_lookup_devt(s, part);
201 if (res)
202 goto done;
203
204 /* try disk name without p<part number> */
205 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
206 goto fail;
207 p[-1] = '\0';
208 res = blk_lookup_devt(s, part);
209 if (res)
210 goto done;
211
212 fail:
213 return 0;
214 done:
215 return res;
216 }
217
root_dev_setup(char * line)218 static int __init root_dev_setup(char *line)
219 {
220 strlcpy(saved_root_name, line, sizeof(saved_root_name));
221 return 1;
222 }
223
224 __setup("root=", root_dev_setup);
225
rootwait_setup(char * str)226 static int __init rootwait_setup(char *str)
227 {
228 if (*str)
229 return 0;
230 root_wait = 1;
231 return 1;
232 }
233
234 __setup("rootwait", rootwait_setup);
235
236 static char * __initdata root_mount_data;
root_data_setup(char * str)237 static int __init root_data_setup(char *str)
238 {
239 root_mount_data = str;
240 return 1;
241 }
242
243 static char * __initdata root_fs_names;
fs_names_setup(char * str)244 static int __init fs_names_setup(char *str)
245 {
246 root_fs_names = str;
247 return 1;
248 }
249
250 static unsigned int __initdata root_delay;
root_delay_setup(char * str)251 static int __init root_delay_setup(char *str)
252 {
253 root_delay = simple_strtoul(str, NULL, 0);
254 return 1;
255 }
256
257 __setup("rootflags=", root_data_setup);
258 __setup("rootfstype=", fs_names_setup);
259 __setup("rootdelay=", root_delay_setup);
260
get_fs_names(char * page)261 static void __init get_fs_names(char *page)
262 {
263 char *s = page;
264
265 if (root_fs_names) {
266 strcpy(page, root_fs_names);
267 while (*s++) {
268 if (s[-1] == ',')
269 s[-1] = '\0';
270 }
271 } else {
272 int len = get_filesystem_list(page);
273 char *p, *next;
274
275 page[len] = '\0';
276 for (p = page-1; p; p = next) {
277 next = strchr(++p, '\n');
278 if (*p++ != '\t')
279 continue;
280 while ((*s++ = *p++) != '\n')
281 ;
282 s[-1] = '\0';
283 }
284 }
285 *s = '\0';
286 }
287
do_mount_root(char * name,char * fs,int flags,void * data)288 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
289 {
290 int err = sys_mount(name, "/root", fs, flags, data);
291 if (err)
292 return err;
293
294 sys_chdir((const char __user __force *)"/root");
295 ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
296 printk(KERN_INFO
297 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
298 current->fs->pwd.mnt->mnt_sb->s_type->name,
299 current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
300 " readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
301 return 0;
302 }
303
mount_block_root(char * name,int flags)304 void __init mount_block_root(char *name, int flags)
305 {
306 char *fs_names = __getname_gfp(GFP_KERNEL
307 | __GFP_NOTRACK_FALSE_POSITIVE);
308 char *p;
309 #ifdef CONFIG_BLOCK
310 char b[BDEVNAME_SIZE];
311 #else
312 const char *b = name;
313 #endif
314
315 get_fs_names(fs_names);
316 retry:
317 for (p = fs_names; *p; p += strlen(p)+1) {
318 int err = do_mount_root(name, p, flags, root_mount_data);
319 switch (err) {
320 case 0:
321 goto out;
322 case -EACCES:
323 flags |= MS_RDONLY;
324 goto retry;
325 case -EINVAL:
326 continue;
327 }
328 /*
329 * Allow the user to distinguish between failed sys_open
330 * and bad superblock on root device.
331 * and give them a list of the available devices
332 */
333 #ifdef CONFIG_BLOCK
334 __bdevname(ROOT_DEV, b);
335 #endif
336 printk("VFS: Cannot open root device \"%s\" or %s\n",
337 root_device_name, b);
338 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
339
340 printk_all_partitions();
341 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
342 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
343 "explicit textual name for \"root=\" boot option.\n");
344 #endif
345 panic("VFS: Unable to mount root fs on %s", b);
346 }
347
348 printk("List of all partitions:\n");
349 printk_all_partitions();
350 printk("No filesystem could mount root, tried: ");
351 for (p = fs_names; *p; p += strlen(p)+1)
352 printk(" %s", p);
353 printk("\n");
354 #ifdef CONFIG_BLOCK
355 __bdevname(ROOT_DEV, b);
356 #endif
357 panic("VFS: Unable to mount root fs on %s", b);
358 out:
359 putname(fs_names);
360 }
361
362 #ifdef CONFIG_ROOT_NFS
mount_nfs_root(void)363 static int __init mount_nfs_root(void)
364 {
365 char *root_dev, *root_data;
366
367 if (nfs_root_data(&root_dev, &root_data) != 0)
368 return 0;
369 if (do_mount_root(root_dev, "nfs", root_mountflags, root_data) != 0)
370 return 0;
371 return 1;
372 }
373 #endif
374
375 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
change_floppy(char * fmt,...)376 void __init change_floppy(char *fmt, ...)
377 {
378 struct termios termios;
379 char buf[80];
380 char c;
381 int fd;
382 va_list args;
383 va_start(args, fmt);
384 vsprintf(buf, fmt, args);
385 va_end(args);
386 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
387 if (fd >= 0) {
388 sys_ioctl(fd, FDEJECT, 0);
389 sys_close(fd);
390 }
391 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
392 fd = sys_open("/dev/console", O_RDWR, 0);
393 if (fd >= 0) {
394 sys_ioctl(fd, TCGETS, (long)&termios);
395 termios.c_lflag &= ~ICANON;
396 sys_ioctl(fd, TCSETSF, (long)&termios);
397 sys_read(fd, &c, 1);
398 termios.c_lflag |= ICANON;
399 sys_ioctl(fd, TCSETSF, (long)&termios);
400 sys_close(fd);
401 }
402 }
403 #endif
404
mount_root(void)405 void __init mount_root(void)
406 {
407 #ifdef CONFIG_ROOT_NFS
408 if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
409 if (mount_nfs_root())
410 return;
411
412 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
413 ROOT_DEV = Root_FD0;
414 }
415 #endif
416 #ifdef CONFIG_BLK_DEV_FD
417 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
418 /* rd_doload is 2 for a dual initrd/ramload setup */
419 if (rd_doload==2) {
420 if (rd_load_disk(1)) {
421 ROOT_DEV = Root_RAM1;
422 root_device_name = NULL;
423 }
424 } else
425 change_floppy("root floppy");
426 }
427 #endif
428 #ifdef CONFIG_BLOCK
429 create_dev("/dev/root", ROOT_DEV);
430 mount_block_root("/dev/root", root_mountflags);
431 #endif
432 }
433
434 /*
435 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
436 */
prepare_namespace(void)437 void __init prepare_namespace(void)
438 {
439 int is_floppy;
440
441 if (root_delay) {
442 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
443 root_delay);
444 ssleep(root_delay);
445 }
446
447 /*
448 * wait for the known devices to complete their probing
449 *
450 * Note: this is a potential source of long boot delays.
451 * For example, it is not atypical to wait 5 seconds here
452 * for the touchpad of a laptop to initialize.
453 */
454 wait_for_device_probe();
455
456 md_run_setup();
457
458 if (saved_root_name[0]) {
459 root_device_name = saved_root_name;
460 if (!strncmp(root_device_name, "mtd", 3) ||
461 !strncmp(root_device_name, "ubi", 3)) {
462 mount_block_root(root_device_name, root_mountflags);
463 goto out;
464 }
465 ROOT_DEV = name_to_dev_t(root_device_name);
466 if (strncmp(root_device_name, "/dev/", 5) == 0)
467 root_device_name += 5;
468 }
469
470 if (initrd_load())
471 goto out;
472
473 /* wait for any asynchronous scanning to complete */
474 if ((ROOT_DEV == 0) && root_wait) {
475 printk(KERN_INFO "Waiting for root device %s...\n",
476 saved_root_name);
477 while (driver_probe_done() != 0 ||
478 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
479 msleep(100);
480 async_synchronize_full();
481 }
482
483 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
484
485 if (is_floppy && rd_doload && rd_load_disk(0))
486 ROOT_DEV = Root_RAM0;
487
488 mount_root();
489 out:
490 devtmpfs_mount("dev");
491 sys_mount(".", "/", NULL, MS_MOVE, NULL);
492 sys_chroot((const char __user __force *)".");
493 }
494