blob: b6237c31b0e2469cac9b2287cecb6932ad49462e [file] [log] [blame]
H Hartley Sweetenc67e5382012-05-31 16:26:10 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#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>
Dave Gilbertdd2a3452007-05-09 02:33:24 -070020#include <linux/genhd.h>
Andrew Mortond53d9f12005-07-12 13:58:07 -070021#include <linux/mount.h>
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -070022#include <linux/device.h>
Adrian Bunk46595392007-05-08 00:24:47 -070023#include <linux/init.h>
Adrian Bunk011e3fc2008-02-06 01:36:47 -080024#include <linux/fs.h>
Adrian Bunk82c82532008-07-25 01:45:29 -070025#include <linux/initrd.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080026#include <linux/async.h>
Al Viro5ad4e532009-03-29 19:50:06 -040027#include <linux/fs_struct.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Rob Landley57f150a2013-09-11 14:26:10 -070029#include <linux/ramfs.h>
Rob Landley16203a72013-09-11 14:26:12 -070030#include <linux/shmem_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070038int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
39
Theodore Ts'o9b04c992006-03-24 03:15:10 -080040int root_mountflags = MS_RDONLY | MS_SILENT;
Adrian Bunkf56f6d302008-07-25 19:46:25 -070041static char * __initdata root_device_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042static char __initdata saved_root_name[64];
Will Drewry79975f12011-11-02 13:38:59 -070043static int root_wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
Linus Torvalds1da177e2005-04-16 15:20:36 -070045dev_t ROOT_DEV;
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047static 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
Jens Axboe6d0aed72010-09-17 10:00:46 +020073#ifdef CONFIG_BLOCK
Stephen Warren1ad7e892012-11-08 16:12:25 -080074struct uuidcmp {
75 const char *uuid;
76 int len;
77};
78
Will Drewryb5af9212010-08-31 15:47:07 -050079/**
80 * match_dev_by_uuid - callback for finding a partition using its uuid
81 * @dev: device passed in by the caller
Stephen Warren1ad7e892012-11-08 16:12:25 -080082 * @data: opaque pointer to the desired struct uuidcmp to match
Will Drewryb5af9212010-08-31 15:47:07 -050083 *
84 * Returns 1 if the device matches, and 0 otherwise.
85 */
Michał Mirosław9f3b7952013-02-01 20:40:17 +010086static int match_dev_by_uuid(struct device *dev, const void *data)
Will Drewryb5af9212010-08-31 15:47:07 -050087{
Michał Mirosław9f3b7952013-02-01 20:40:17 +010088 const struct uuidcmp *cmp = data;
Will Drewryb5af9212010-08-31 15:47:07 -050089 struct hd_struct *part = dev_to_part(dev);
90
91 if (!part->info)
92 goto no_match;
93
Stephen Warren1ad7e892012-11-08 16:12:25 -080094 if (strncasecmp(cmp->uuid, part->info->uuid, cmp->len))
95 goto no_match;
Will Drewryb5af9212010-08-31 15:47:07 -050096
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
chishanmingshena68b3102014-04-03 14:49:35 -0700105 * @uuid_str: char array containing ascii UUID
Will Drewryb5af9212010-08-31 15:47:07 -0500106 *
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 *
chishanmingshena68b3102014-04-03 14:49:35 -0700111 * If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be
Will Drewry79975f12011-11-02 13:38:59 -0700112 * extracted and used as an offset from the partition identified by the UUID.
113 *
Will Drewryb5af9212010-08-31 15:47:07 -0500114 * Returns the matching dev_t on success or 0 on failure.
115 */
Stephen Warren1ad7e892012-11-08 16:12:25 -0800116static dev_t devt_from_partuuid(const char *uuid_str)
Will Drewryb5af9212010-08-31 15:47:07 -0500117{
118 dev_t res = 0;
Stephen Warren1ad7e892012-11-08 16:12:25 -0800119 struct uuidcmp cmp;
Will Drewryb5af9212010-08-31 15:47:07 -0500120 struct device *dev = NULL;
Will Drewry79975f12011-11-02 13:38:59 -0700121 struct gendisk *disk;
122 struct hd_struct *part;
123 int offset = 0;
Stephen Warren283f8fc2012-11-08 16:12:27 -0800124 bool clear_root_wait = false;
125 char *slash;
Will Drewry79975f12011-11-02 13:38:59 -0700126
Stephen Warren1ad7e892012-11-08 16:12:25 -0800127 cmp.uuid = uuid_str;
Stephen Warren1ad7e892012-11-08 16:12:25 -0800128
Stephen Warren283f8fc2012-11-08 16:12:27 -0800129 slash = strchr(uuid_str, '/');
Will Drewry79975f12011-11-02 13:38:59 -0700130 /* Check for optional partition number offset attributes. */
Stephen Warren283f8fc2012-11-08 16:12:27 -0800131 if (slash) {
Will Drewry79975f12011-11-02 13:38:59 -0700132 char c = 0;
133 /* Explicitly fail on poor PARTUUID syntax. */
Stephen Warren283f8fc2012-11-08 16:12:27 -0800134 if (sscanf(slash + 1,
135 "PARTNROFF=%d%c", &offset, &c) != 1) {
136 clear_root_wait = true;
Will Drewry79975f12011-11-02 13:38:59 -0700137 goto done;
138 }
Stephen Warren283f8fc2012-11-08 16:12:27 -0800139 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;
Will Drewry79975f12011-11-02 13:38:59 -0700147 }
Will Drewryb5af9212010-08-31 15:47:07 -0500148
Stephen Warren1ad7e892012-11-08 16:12:25 -0800149 dev = class_find_device(&block_class, NULL, &cmp,
150 &match_dev_by_uuid);
Will Drewryb5af9212010-08-31 15:47:07 -0500151 if (!dev)
152 goto done;
153
154 res = dev->devt;
Will Drewryb5af9212010-08-31 15:47:07 -0500155
Will Drewry79975f12011-11-02 13:38:59 -0700156 /* 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);
Will Drewryb5af9212010-08-31 15:47:07 -0500170done:
Stephen Warren283f8fc2012-11-08 16:12:27 -0800171 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 }
Will Drewryb5af9212010-08-31 15:47:07 -0500178 return res;
179}
Jens Axboe6d0aed72010-09-17 10:00:46 +0200180#endif
Will Drewryb5af9212010-08-31 15:47:07 -0500181
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182/*
183 * Convert a name into device number. We accept the following variants:
184 *
185 * 1) device number in hexadecimal represents itself
186 * 2) /dev/nfs represents Root_NFS (0xff)
187 * 3) /dev/<disk_name> represents the device number of disk
188 * 4) /dev/<disk_name><decimal> represents the device number
189 * of partition - device number of disk plus the partition number
190 * 5) /dev/<disk_name>p<decimal> - same as the above, that form is
191 * used when disk name of partitioned disk ends on a digit.
Will Drewryb5af9212010-08-31 15:47:07 -0500192 * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the
193 * unique id of a partition if the partition table provides it.
Stephen Warrend33b98f2012-11-08 16:12:28 -0800194 * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS
195 * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero-
196 * filled hex representation of the 32-bit "NT disk signature", and PP
197 * is a zero-filled hex representation of the 1-based partition number.
Will Drewry79975f12011-11-02 13:38:59 -0700198 * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to
199 * a partition with a known unique id.
Sebastian Capella6c251612013-11-12 15:08:39 -0800200 * 8) <major>:<minor> major and minor number of the device separated by
201 * a colon.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 *
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200203 * If name doesn't have fall into the categories above, we return (0,0).
204 * block_class is used to check if something is a disk name. If the disk
205 * name contains slashes, the device name has them replaced with
206 * bangs.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 */
208
209dev_t name_to_dev_t(char *name)
210{
211 char s[32];
212 char *p;
213 dev_t res = 0;
Kay Sievers30f2f0e2008-05-06 22:31:33 +0200214 int part;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
Jens Axboe6d0aed72010-09-17 10:00:46 +0200216#ifdef CONFIG_BLOCK
Will Drewryb5af9212010-08-31 15:47:07 -0500217 if (strncmp(name, "PARTUUID=", 9) == 0) {
218 name += 9;
Will Drewryb5af9212010-08-31 15:47:07 -0500219 res = devt_from_partuuid(name);
220 if (!res)
221 goto fail;
222 goto done;
223 }
Jens Axboe6d0aed72010-09-17 10:00:46 +0200224#endif
Will Drewryb5af9212010-08-31 15:47:07 -0500225
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 if (strncmp(name, "/dev/", 5) != 0) {
227 unsigned maj, min;
228
229 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
230 res = MKDEV(maj, min);
231 if (maj != MAJOR(res) || min != MINOR(res))
232 goto fail;
233 } else {
234 res = new_decode_dev(simple_strtoul(name, &p, 16));
235 if (*p)
236 goto fail;
237 }
238 goto done;
239 }
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200240
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 name += 5;
242 res = Root_NFS;
243 if (strcmp(name, "nfs") == 0)
244 goto done;
245 res = Root_RAM0;
246 if (strcmp(name, "ram") == 0)
247 goto done;
248
249 if (strlen(name) > 31)
250 goto fail;
251 strcpy(s, name);
252 for (p = s; *p; p++)
253 if (*p == '/')
254 *p = '!';
Kay Sievers30f2f0e2008-05-06 22:31:33 +0200255 res = blk_lookup_devt(s, 0);
256 if (res)
257 goto done;
258
259 /*
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300260 * try non-existent, but valid partition, which may only exist
Kay Sievers30f2f0e2008-05-06 22:31:33 +0200261 * after revalidating the disk, like partitioned md devices
262 */
263 while (p > s && isdigit(p[-1]))
264 p--;
265 if (p == s || !*p || *p == '0')
266 goto fail;
267
268 /* try disk name without <part number> */
269 part = simple_strtoul(p, NULL, 10);
270 *p = '\0';
271 res = blk_lookup_devt(s, part);
272 if (res)
273 goto done;
274
275 /* try disk name without p<part number> */
276 if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
277 goto fail;
278 p[-1] = '\0';
279 res = blk_lookup_devt(s, part);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 if (res)
281 goto done;
282
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283fail:
Kay Sieversedfaa7c2007-05-21 22:08:01 +0200284 return 0;
285done:
286 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287}
288
289static int __init root_dev_setup(char *line)
290{
291 strlcpy(saved_root_name, line, sizeof(saved_root_name));
292 return 1;
293}
294
295__setup("root=", root_dev_setup);
296
Pierre Ossmancc1ed752007-07-15 23:40:35 -0700297static int __init rootwait_setup(char *str)
298{
299 if (*str)
300 return 0;
301 root_wait = 1;
302 return 1;
303}
304
305__setup("rootwait", rootwait_setup);
306
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307static char * __initdata root_mount_data;
308static int __init root_data_setup(char *str)
309{
310 root_mount_data = str;
311 return 1;
312}
313
314static char * __initdata root_fs_names;
315static int __init fs_names_setup(char *str)
316{
317 root_fs_names = str;
318 return 1;
319}
320
321static unsigned int __initdata root_delay;
322static int __init root_delay_setup(char *str)
323{
324 root_delay = simple_strtoul(str, NULL, 0);
325 return 1;
326}
327
328__setup("rootflags=", root_data_setup);
329__setup("rootfstype=", fs_names_setup);
330__setup("rootdelay=", root_delay_setup);
331
332static void __init get_fs_names(char *page)
333{
334 char *s = page;
335
336 if (root_fs_names) {
337 strcpy(page, root_fs_names);
338 while (*s++) {
339 if (s[-1] == ',')
340 s[-1] = '\0';
341 }
342 } else {
343 int len = get_filesystem_list(page);
344 char *p, *next;
345
346 page[len] = '\0';
347 for (p = page-1; p; p = next) {
348 next = strchr(++p, '\n');
349 if (*p++ != '\t')
350 continue;
351 while ((*s++ = *p++) != '\n')
352 ;
353 s[-1] = '\0';
354 }
355 }
356 *s = '\0';
357}
358
359static int __init do_mount_root(char *name, char *fs, int flags, void *data)
360{
Al Virod8c95842011-12-07 18:16:57 -0500361 struct super_block *s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 int err = sys_mount(name, "/root", fs, flags, data);
363 if (err)
364 return err;
365
H Hartley Sweetenc67e5382012-05-31 16:26:10 -0700366 sys_chdir("/root");
Al Virod8c95842011-12-07 18:16:57 -0500367 s = current->fs->pwd.dentry->d_sb;
368 ROOT_DEV = s->s_dev;
Mandeep Singh Baines80cdc6d2011-03-22 16:33:54 -0700369 printk(KERN_INFO
370 "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
Al Virod8c95842011-12-07 18:16:57 -0500371 s->s_type->name,
372 s->s_flags & MS_RDONLY ? " readonly" : "",
373 MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 return 0;
375}
376
377void __init mount_block_root(char *name, int flags)
378{
Jeff Laytona608ca22012-10-10 15:25:26 -0400379 struct page *page = alloc_page(GFP_KERNEL |
380 __GFP_NOTRACK_FALSE_POSITIVE);
381 char *fs_names = page_address(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 char *p;
David Howells93614012006-09-30 20:45:40 +0200383#ifdef CONFIG_BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 char b[BDEVNAME_SIZE];
David Howells93614012006-09-30 20:45:40 +0200385#else
386 const char *b = name;
387#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
389 get_fs_names(fs_names);
390retry:
391 for (p = fs_names; *p; p += strlen(p)+1) {
392 int err = do_mount_root(name, p, flags, root_mount_data);
393 switch (err) {
394 case 0:
395 goto out;
396 case -EACCES:
397 flags |= MS_RDONLY;
398 goto retry;
399 case -EINVAL:
400 continue;
401 }
402 /*
403 * Allow the user to distinguish between failed sys_open
404 * and bad superblock on root device.
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700405 * and give them a list of the available devices
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 */
David Howells93614012006-09-30 20:45:40 +0200407#ifdef CONFIG_BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 __bdevname(ROOT_DEV, b);
David Howells93614012006-09-30 20:45:40 +0200409#endif
Bernhard Walle0e0cb892012-03-23 15:02:28 -0700410 printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
411 root_device_name, b, err);
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700412 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700414 printk_all_partitions();
Tejun Heo55dc7db2008-09-01 13:44:35 +0200415#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
416 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
417 "explicit textual name for \"root=\" boot option.\n");
418#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 panic("VFS: Unable to mount root fs on %s", b);
420 }
Andy Whitcroftbe6e028b2006-05-15 09:44:29 -0700421
Dave Gilbertdd2a3452007-05-09 02:33:24 -0700422 printk("List of all partitions:\n");
423 printk_all_partitions();
Andy Whitcroftbe6e028b2006-05-15 09:44:29 -0700424 printk("No filesystem could mount root, tried: ");
425 for (p = fs_names; *p; p += strlen(p)+1)
426 printk(" %s", p);
427 printk("\n");
David Howells93614012006-09-30 20:45:40 +0200428#ifdef CONFIG_BLOCK
429 __bdevname(ROOT_DEV, b);
430#endif
431 panic("VFS: Unable to mount root fs on %s", b);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432out:
Jeff Laytona608ca22012-10-10 15:25:26 -0400433 put_page(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434}
435
436#ifdef CONFIG_ROOT_NFS
Chuck Lever43717c72011-12-05 15:40:30 -0500437
438#define NFSROOT_TIMEOUT_MIN 5
439#define NFSROOT_TIMEOUT_MAX 30
440#define NFSROOT_RETRY_MAX 5
441
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442static int __init mount_nfs_root(void)
443{
Chuck Lever56463e52010-09-17 10:54:37 -0400444 char *root_dev, *root_data;
Chuck Lever43717c72011-12-05 15:40:30 -0500445 unsigned int timeout;
446 int try, err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
Chuck Lever43717c72011-12-05 15:40:30 -0500448 err = nfs_root_data(&root_dev, &root_data);
449 if (err != 0)
Chuck Lever56463e52010-09-17 10:54:37 -0400450 return 0;
Chuck Lever43717c72011-12-05 15:40:30 -0500451
452 /*
453 * The server or network may not be ready, so try several
454 * times. Stop after a few tries in case the client wants
455 * to fall back to other boot methods.
456 */
457 timeout = NFSROOT_TIMEOUT_MIN;
458 for (try = 1; ; try++) {
459 err = do_mount_root(root_dev, "nfs",
460 root_mountflags, root_data);
461 if (err == 0)
462 return 1;
463 if (try > NFSROOT_RETRY_MAX)
464 break;
465
466 /* Wait, in case the server refused us immediately */
467 ssleep(timeout);
468 timeout <<= 1;
469 if (timeout > NFSROOT_TIMEOUT_MAX)
470 timeout = NFSROOT_TIMEOUT_MAX;
471 }
472 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473}
474#endif
475
476#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
477void __init change_floppy(char *fmt, ...)
478{
479 struct termios termios;
480 char buf[80];
481 char c;
482 int fd;
483 va_list args;
484 va_start(args, fmt);
485 vsprintf(buf, fmt, args);
486 va_end(args);
487 fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
488 if (fd >= 0) {
489 sys_ioctl(fd, FDEJECT, 0);
490 sys_close(fd);
491 }
492 printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
493 fd = sys_open("/dev/console", O_RDWR, 0);
494 if (fd >= 0) {
495 sys_ioctl(fd, TCGETS, (long)&termios);
496 termios.c_lflag &= ~ICANON;
497 sys_ioctl(fd, TCSETSF, (long)&termios);
498 sys_read(fd, &c, 1);
499 termios.c_lflag |= ICANON;
500 sys_ioctl(fd, TCSETSF, (long)&termios);
501 sys_close(fd);
502 }
503}
504#endif
505
506void __init mount_root(void)
507{
508#ifdef CONFIG_ROOT_NFS
Sasha Levin377485f2012-05-05 17:06:35 +0200509 if (ROOT_DEV == Root_NFS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 if (mount_nfs_root())
511 return;
512
513 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
514 ROOT_DEV = Root_FD0;
515 }
516#endif
517#ifdef CONFIG_BLK_DEV_FD
518 if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
519 /* rd_doload is 2 for a dual initrd/ramload setup */
520 if (rd_doload==2) {
521 if (rd_load_disk(1)) {
522 ROOT_DEV = Root_RAM1;
523 root_device_name = NULL;
524 }
525 } else
526 change_floppy("root floppy");
527 }
528#endif
David Howells93614012006-09-30 20:45:40 +0200529#ifdef CONFIG_BLOCK
Greg Kroah-Hartmanbdaf8522005-06-20 21:15:16 -0700530 create_dev("/dev/root", ROOT_DEV);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 mount_block_root("/dev/root", root_mountflags);
David Howells93614012006-09-30 20:45:40 +0200532#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533}
534
535/*
536 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
537 */
538void __init prepare_namespace(void)
539{
540 int is_floppy;
541
Arjan van de Ven216773a2009-02-14 01:59:06 +0100542 /*
543 * wait for the known devices to complete their probing
544 *
545 * Note: this is a potential source of long boot delays.
546 * For example, it is not atypical to wait 5 seconds here
547 * for the touchpad of a laptop to initialize.
548 */
549 wait_for_device_probe();
Greg Kroah-Hartmand7792492006-07-18 10:59:59 -0700550
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 md_run_setup();
552
553 if (saved_root_name[0]) {
554 root_device_name = saved_root_name;
Adrian Hunter2d62f482008-01-31 17:25:00 +0200555 if (!strncmp(root_device_name, "mtd", 3) ||
556 !strncmp(root_device_name, "ubi", 3)) {
Joern Engele9482b42006-05-30 14:25:46 +0200557 mount_block_root(root_device_name, root_mountflags);
558 goto out;
559 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 ROOT_DEV = name_to_dev_t(root_device_name);
561 if (strncmp(root_device_name, "/dev/", 5) == 0)
562 root_device_name += 5;
563 }
564
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 if (initrd_load())
566 goto out;
567
Paul Gortmaker4dfe6942014-08-08 14:19:46 -0700568 if (root_delay) {
569 pr_info("Waiting %d sec before mounting root device...\n",
570 root_delay);
571 ssleep(root_delay);
572 }
573
Pierre Ossmancc1ed752007-07-15 23:40:35 -0700574 /* wait for any asynchronous scanning to complete */
575 if ((ROOT_DEV == 0) && root_wait) {
576 printk(KERN_INFO "Waiting for root device %s...\n",
577 saved_root_name);
578 while (driver_probe_done() != 0 ||
579 (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
580 msleep(100);
Arjan van de Ven216773a2009-02-14 01:59:06 +0100581 async_synchronize_full();
Pierre Ossmancc1ed752007-07-15 23:40:35 -0700582 }
583
584 is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
585
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 if (is_floppy && rd_doload && rd_load_disk(0))
587 ROOT_DEV = Root_RAM0;
588
589 mount_root();
590out:
Kay Sievers2b2af542009-04-30 15:23:42 +0200591 devtmpfs_mount("dev");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 sys_mount(".", "/", NULL, MS_MOVE, NULL);
H Hartley Sweetenc67e5382012-05-31 16:26:10 -0700593 sys_chroot(".");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594}
Rob Landley57f150a2013-09-11 14:26:10 -0700595
Rob Landley6e19ede2013-09-11 14:26:13 -0700596static bool is_tmpfs;
Rob Landley57f150a2013-09-11 14:26:10 -0700597static struct dentry *rootfs_mount(struct file_system_type *fs_type,
598 int flags, const char *dev_name, void *data)
599{
600 static unsigned long once;
Rob Landley6e19ede2013-09-11 14:26:13 -0700601 void *fill = ramfs_fill_super;
Rob Landley57f150a2013-09-11 14:26:10 -0700602
603 if (test_and_set_bit(0, &once))
604 return ERR_PTR(-ENODEV);
605
Rob Landley6e19ede2013-09-11 14:26:13 -0700606 if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
607 fill = shmem_fill_super;
608
609 return mount_nodev(fs_type, flags, data, fill);
Rob Landley57f150a2013-09-11 14:26:10 -0700610}
611
612static struct file_system_type rootfs_fs_type = {
613 .name = "rootfs",
614 .mount = rootfs_mount,
615 .kill_sb = kill_litter_super,
616};
617
618int __init init_rootfs(void)
619{
620 int err = register_filesystem(&rootfs_fs_type);
621
622 if (err)
623 return err;
624
Rob Landley6e19ede2013-09-11 14:26:13 -0700625 if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
626 (!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
Rob Landley16203a72013-09-11 14:26:12 -0700627 err = shmem_init();
Rob Landley6e19ede2013-09-11 14:26:13 -0700628 is_tmpfs = true;
629 } else {
Rob Landley16203a72013-09-11 14:26:12 -0700630 err = init_ramfs_fs();
Rob Landley6e19ede2013-09-11 14:26:13 -0700631 }
Rob Landley16203a72013-09-11 14:26:12 -0700632
Rob Landley57f150a2013-09-11 14:26:10 -0700633 if (err)
634 unregister_filesystem(&rootfs_fs_type);
635
636 return err;
637}