xref: /linux/init/do_mounts.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
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 
15 #include <linux/nfs_fs.h>
16 #include <linux/nfs_fs_sb.h>
17 #include <linux/nfs_mount.h>
18 
19 #include "do_mounts.h"
20 
21 extern int get_filesystem_list(char * buf);
22 
23 int __initdata rd_doload;	/* 1 = load RAM disk, 0 = don't load */
24 
25 int root_mountflags = MS_RDONLY | MS_SILENT;
26 char * __initdata root_device_name;
27 static char __initdata saved_root_name[64];
28 static int __initdata root_wait;
29 
30 dev_t ROOT_DEV;
31 
32 static int __init load_ramdisk(char *str)
33 {
34 	rd_doload = simple_strtol(str,NULL,0) & 3;
35 	return 1;
36 }
37 __setup("load_ramdisk=", load_ramdisk);
38 
39 static int __init readonly(char *str)
40 {
41 	if (*str)
42 		return 0;
43 	root_mountflags |= MS_RDONLY;
44 	return 1;
45 }
46 
47 static int __init readwrite(char *str)
48 {
49 	if (*str)
50 		return 0;
51 	root_mountflags &= ~MS_RDONLY;
52 	return 1;
53 }
54 
55 __setup("ro", readonly);
56 __setup("rw", readwrite);
57 
58 static dev_t try_name(char *name, int part)
59 {
60 	char path[64];
61 	char buf[32];
62 	int range;
63 	dev_t res;
64 	char *s;
65 	int len;
66 	int fd;
67 	unsigned int maj, min;
68 
69 	/* read device number from .../dev */
70 
71 	sprintf(path, "/sys/block/%s/dev", name);
72 	fd = sys_open(path, 0, 0);
73 	if (fd < 0)
74 		goto fail;
75 	len = sys_read(fd, buf, 32);
76 	sys_close(fd);
77 	if (len <= 0 || len == 32 || buf[len - 1] != '\n')
78 		goto fail;
79 	buf[len - 1] = '\0';
80 	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
81 		/*
82 		 * Try the %u:%u format -- see print_dev_t()
83 		 */
84 		res = MKDEV(maj, min);
85 		if (maj != MAJOR(res) || min != MINOR(res))
86 			goto fail;
87 	} else {
88 		/*
89 		 * Nope.  Try old-style "0321"
90 		 */
91 		res = new_decode_dev(simple_strtoul(buf, &s, 16));
92 		if (*s)
93 			goto fail;
94 	}
95 
96 	/* if it's there and we are not looking for a partition - that's it */
97 	if (!part)
98 		return res;
99 
100 	/* otherwise read range from .../range */
101 	sprintf(path, "/sys/block/%s/range", name);
102 	fd = sys_open(path, 0, 0);
103 	if (fd < 0)
104 		goto fail;
105 	len = sys_read(fd, buf, 32);
106 	sys_close(fd);
107 	if (len <= 0 || len == 32 || buf[len - 1] != '\n')
108 		goto fail;
109 	buf[len - 1] = '\0';
110 	range = simple_strtoul(buf, &s, 10);
111 	if (*s)
112 		goto fail;
113 
114 	/* if partition is within range - we got it */
115 	if (part < range)
116 		return res + part;
117 fail:
118 	return 0;
119 }
120 
121 /*
122  *	Convert a name into device number.  We accept the following variants:
123  *
124  *	1) device number in hexadecimal	represents itself
125  *	2) /dev/nfs represents Root_NFS (0xff)
126  *	3) /dev/<disk_name> represents the device number of disk
127  *	4) /dev/<disk_name><decimal> represents the device number
128  *         of partition - device number of disk plus the partition number
129  *	5) /dev/<disk_name>p<decimal> - same as the above, that form is
130  *	   used when disk name of partitioned disk ends on a digit.
131  *
132  *	If name doesn't have fall into the categories above, we return 0.
133  *	Sysfs is used to check if something is a disk name - it has
134  *	all known disks under bus/block/devices.  If the disk name
135  *	contains slashes, name of sysfs node has them replaced with
136  *	bangs.  try_name() does the actual checks, assuming that sysfs
137  *	is mounted on rootfs /sys.
138  */
139 
140 dev_t name_to_dev_t(char *name)
141 {
142 	char s[32];
143 	char *p;
144 	dev_t res = 0;
145 	int part;
146 
147 #ifdef CONFIG_SYSFS
148 	int mkdir_err = sys_mkdir("/sys", 0700);
149 	if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
150 		goto out;
151 #endif
152 
153 	if (strncmp(name, "/dev/", 5) != 0) {
154 		unsigned maj, min;
155 
156 		if (sscanf(name, "%u:%u", &maj, &min) == 2) {
157 			res = MKDEV(maj, min);
158 			if (maj != MAJOR(res) || min != MINOR(res))
159 				goto fail;
160 		} else {
161 			res = new_decode_dev(simple_strtoul(name, &p, 16));
162 			if (*p)
163 				goto fail;
164 		}
165 		goto done;
166 	}
167 	name += 5;
168 	res = Root_NFS;
169 	if (strcmp(name, "nfs") == 0)
170 		goto done;
171 	res = Root_RAM0;
172 	if (strcmp(name, "ram") == 0)
173 		goto done;
174 
175 	if (strlen(name) > 31)
176 		goto fail;
177 	strcpy(s, name);
178 	for (p = s; *p; p++)
179 		if (*p == '/')
180 			*p = '!';
181 	res = try_name(s, 0);
182 	if (res)
183 		goto done;
184 
185 	while (p > s && isdigit(p[-1]))
186 		p--;
187 	if (p == s || !*p || *p == '0')
188 		goto fail;
189 	part = simple_strtoul(p, NULL, 10);
190 	*p = '\0';
191 	res = try_name(s, part);
192 	if (res)
193 		goto done;
194 
195 	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
196 		goto fail;
197 	p[-1] = '\0';
198 	res = try_name(s, part);
199 done:
200 #ifdef CONFIG_SYSFS
201 	sys_umount("/sys", 0);
202 out:
203 	if (!mkdir_err)
204 		sys_rmdir("/sys");
205 #endif
206 	return res;
207 fail:
208 	res = 0;
209 	goto done;
210 }
211 
212 static int __init root_dev_setup(char *line)
213 {
214 	strlcpy(saved_root_name, line, sizeof(saved_root_name));
215 	return 1;
216 }
217 
218 __setup("root=", root_dev_setup);
219 
220 static int __init rootwait_setup(char *str)
221 {
222 	if (*str)
223 		return 0;
224 	root_wait = 1;
225 	return 1;
226 }
227 
228 __setup("rootwait", rootwait_setup);
229 
230 static char * __initdata root_mount_data;
231 static int __init root_data_setup(char *str)
232 {
233 	root_mount_data = str;
234 	return 1;
235 }
236 
237 static char * __initdata root_fs_names;
238 static int __init fs_names_setup(char *str)
239 {
240 	root_fs_names = str;
241 	return 1;
242 }
243 
244 static unsigned int __initdata root_delay;
245 static int __init root_delay_setup(char *str)
246 {
247 	root_delay = simple_strtoul(str, NULL, 0);
248 	return 1;
249 }
250 
251 __setup("rootflags=", root_data_setup);
252 __setup("rootfstype=", fs_names_setup);
253 __setup("rootdelay=", root_delay_setup);
254 
255 static void __init get_fs_names(char *page)
256 {
257 	char *s = page;
258 
259 	if (root_fs_names) {
260 		strcpy(page, root_fs_names);
261 		while (*s++) {
262 			if (s[-1] == ',')
263 				s[-1] = '\0';
264 		}
265 	} else {
266 		int len = get_filesystem_list(page);
267 		char *p, *next;
268 
269 		page[len] = '\0';
270 		for (p = page-1; p; p = next) {
271 			next = strchr(++p, '\n');
272 			if (*p++ != '\t')
273 				continue;
274 			while ((*s++ = *p++) != '\n')
275 				;
276 			s[-1] = '\0';
277 		}
278 	}
279 	*s = '\0';
280 }
281 
282 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
283 {
284 	int err = sys_mount(name, "/root", fs, flags, data);
285 	if (err)
286 		return err;
287 
288 	sys_chdir("/root");
289 	ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
290 	printk("VFS: Mounted root (%s filesystem)%s.\n",
291 	       current->fs->pwdmnt->mnt_sb->s_type->name,
292 	       current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
293 	       " readonly" : "");
294 	return 0;
295 }
296 
297 void __init mount_block_root(char *name, int flags)
298 {
299 	char *fs_names = __getname();
300 	char *p;
301 #ifdef CONFIG_BLOCK
302 	char b[BDEVNAME_SIZE];
303 #else
304 	const char *b = name;
305 #endif
306 
307 	get_fs_names(fs_names);
308 retry:
309 	for (p = fs_names; *p; p += strlen(p)+1) {
310 		int err = do_mount_root(name, p, flags, root_mount_data);
311 		switch (err) {
312 			case 0:
313 				goto out;
314 			case -EACCES:
315 				flags |= MS_RDONLY;
316 				goto retry;
317 			case -EINVAL:
318 				continue;
319 		}
320 	        /*
321 		 * Allow the user to distinguish between failed sys_open
322 		 * and bad superblock on root device.
323 		 * and give them a list of the available devices
324 		 */
325 #ifdef CONFIG_BLOCK
326 		__bdevname(ROOT_DEV, b);
327 #endif
328 		printk("VFS: Cannot open root device \"%s\" or %s\n",
329 				root_device_name, b);
330 		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
331 
332 		printk_all_partitions();
333 		panic("VFS: Unable to mount root fs on %s", b);
334 	}
335 
336 	printk("List of all partitions:\n");
337 	printk_all_partitions();
338 	printk("No filesystem could mount root, tried: ");
339 	for (p = fs_names; *p; p += strlen(p)+1)
340 		printk(" %s", p);
341 	printk("\n");
342 #ifdef CONFIG_BLOCK
343 	__bdevname(ROOT_DEV, b);
344 #endif
345 	panic("VFS: Unable to mount root fs on %s", b);
346 out:
347 	putname(fs_names);
348 }
349 
350 #ifdef CONFIG_ROOT_NFS
351 static int __init mount_nfs_root(void)
352 {
353 	void *data = nfs_root_data();
354 
355 	create_dev("/dev/root", ROOT_DEV);
356 	if (data &&
357 	    do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
358 		return 1;
359 	return 0;
360 }
361 #endif
362 
363 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
364 void __init change_floppy(char *fmt, ...)
365 {
366 	struct termios termios;
367 	char buf[80];
368 	char c;
369 	int fd;
370 	va_list args;
371 	va_start(args, fmt);
372 	vsprintf(buf, fmt, args);
373 	va_end(args);
374 	fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
375 	if (fd >= 0) {
376 		sys_ioctl(fd, FDEJECT, 0);
377 		sys_close(fd);
378 	}
379 	printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
380 	fd = sys_open("/dev/console", O_RDWR, 0);
381 	if (fd >= 0) {
382 		sys_ioctl(fd, TCGETS, (long)&termios);
383 		termios.c_lflag &= ~ICANON;
384 		sys_ioctl(fd, TCSETSF, (long)&termios);
385 		sys_read(fd, &c, 1);
386 		termios.c_lflag |= ICANON;
387 		sys_ioctl(fd, TCSETSF, (long)&termios);
388 		sys_close(fd);
389 	}
390 }
391 #endif
392 
393 void __init mount_root(void)
394 {
395 #ifdef CONFIG_ROOT_NFS
396 	if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
397 		if (mount_nfs_root())
398 			return;
399 
400 		printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
401 		ROOT_DEV = Root_FD0;
402 	}
403 #endif
404 #ifdef CONFIG_BLK_DEV_FD
405 	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
406 		/* rd_doload is 2 for a dual initrd/ramload setup */
407 		if (rd_doload==2) {
408 			if (rd_load_disk(1)) {
409 				ROOT_DEV = Root_RAM1;
410 				root_device_name = NULL;
411 			}
412 		} else
413 			change_floppy("root floppy");
414 	}
415 #endif
416 #ifdef CONFIG_BLOCK
417 	create_dev("/dev/root", ROOT_DEV);
418 	mount_block_root("/dev/root", root_mountflags);
419 #endif
420 }
421 
422 /*
423  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
424  */
425 void __init prepare_namespace(void)
426 {
427 	int is_floppy;
428 
429 	if (root_delay) {
430 		printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
431 		       root_delay);
432 		ssleep(root_delay);
433 	}
434 
435 	/* wait for the known devices to complete their probing */
436 	while (driver_probe_done() != 0)
437 		msleep(100);
438 
439 	md_run_setup();
440 
441 	if (saved_root_name[0]) {
442 		root_device_name = saved_root_name;
443 		if (!strncmp(root_device_name, "mtd", 3)) {
444 			mount_block_root(root_device_name, root_mountflags);
445 			goto out;
446 		}
447 		ROOT_DEV = name_to_dev_t(root_device_name);
448 		if (strncmp(root_device_name, "/dev/", 5) == 0)
449 			root_device_name += 5;
450 	}
451 
452 	if (initrd_load())
453 		goto out;
454 
455 	/* wait for any asynchronous scanning to complete */
456 	if ((ROOT_DEV == 0) && root_wait) {
457 		printk(KERN_INFO "Waiting for root device %s...\n",
458 			saved_root_name);
459 		while (driver_probe_done() != 0 ||
460 			(ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
461 			msleep(100);
462 	}
463 
464 	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
465 
466 	if (is_floppy && rd_doload && rd_load_disk(0))
467 		ROOT_DEV = Root_RAM0;
468 
469 	mount_root();
470 out:
471 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
472 	sys_chroot(".");
473 	security_sb_post_mountroot();
474 }
475 
476