xref: /openbmc/linux/init/do_mounts.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 
11 #include <linux/nfs_fs.h>
12 #include <linux/nfs_fs_sb.h>
13 #include <linux/nfs_mount.h>
14 
15 #include "do_mounts.h"
16 
17 extern int get_filesystem_list(char * buf);
18 
19 int __initdata rd_doload;	/* 1 = load RAM disk, 0 = don't load */
20 
21 int root_mountflags = MS_RDONLY | MS_VERBOSE;
22 char * __initdata root_device_name;
23 static char __initdata saved_root_name[64];
24 
25 /* this is initialized in init/main.c */
26 dev_t ROOT_DEV;
27 
28 EXPORT_SYMBOL(ROOT_DEV);
29 
30 static int __init load_ramdisk(char *str)
31 {
32 	rd_doload = simple_strtol(str,NULL,0) & 3;
33 	return 1;
34 }
35 __setup("load_ramdisk=", load_ramdisk);
36 
37 static int __init readonly(char *str)
38 {
39 	if (*str)
40 		return 0;
41 	root_mountflags |= MS_RDONLY;
42 	return 1;
43 }
44 
45 static int __init readwrite(char *str)
46 {
47 	if (*str)
48 		return 0;
49 	root_mountflags &= ~MS_RDONLY;
50 	return 1;
51 }
52 
53 __setup("ro", readonly);
54 __setup("rw", readwrite);
55 
56 static dev_t try_name(char *name, int part)
57 {
58 	char path[64];
59 	char buf[32];
60 	int range;
61 	dev_t res;
62 	char *s;
63 	int len;
64 	int fd;
65 	unsigned int maj, min;
66 
67 	/* read device number from .../dev */
68 
69 	sprintf(path, "/sys/block/%s/dev", name);
70 	fd = sys_open(path, 0, 0);
71 	if (fd < 0)
72 		goto fail;
73 	len = sys_read(fd, buf, 32);
74 	sys_close(fd);
75 	if (len <= 0 || len == 32 || buf[len - 1] != '\n')
76 		goto fail;
77 	buf[len - 1] = '\0';
78 	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
79 		/*
80 		 * Try the %u:%u format -- see print_dev_t()
81 		 */
82 		res = MKDEV(maj, min);
83 		if (maj != MAJOR(res) || min != MINOR(res))
84 			goto fail;
85 	} else {
86 		/*
87 		 * Nope.  Try old-style "0321"
88 		 */
89 		res = new_decode_dev(simple_strtoul(buf, &s, 16));
90 		if (*s)
91 			goto fail;
92 	}
93 
94 	/* if it's there and we are not looking for a partition - that's it */
95 	if (!part)
96 		return res;
97 
98 	/* otherwise read range from .../range */
99 	sprintf(path, "/sys/block/%s/range", name);
100 	fd = sys_open(path, 0, 0);
101 	if (fd < 0)
102 		goto fail;
103 	len = sys_read(fd, buf, 32);
104 	sys_close(fd);
105 	if (len <= 0 || len == 32 || buf[len - 1] != '\n')
106 		goto fail;
107 	buf[len - 1] = '\0';
108 	range = simple_strtoul(buf, &s, 10);
109 	if (*s)
110 		goto fail;
111 
112 	/* if partition is within range - we got it */
113 	if (part < range)
114 		return res + part;
115 fail:
116 	return 0;
117 }
118 
119 /*
120  *	Convert a name into device number.  We accept the following variants:
121  *
122  *	1) device number in hexadecimal	represents itself
123  *	2) /dev/nfs represents Root_NFS (0xff)
124  *	3) /dev/<disk_name> represents the device number of disk
125  *	4) /dev/<disk_name><decimal> represents the device number
126  *         of partition - device number of disk plus the partition number
127  *	5) /dev/<disk_name>p<decimal> - same as the above, that form is
128  *	   used when disk name of partitioned disk ends on a digit.
129  *
130  *	If name doesn't have fall into the categories above, we return 0.
131  *	Driverfs is used to check if something is a disk name - it has
132  *	all known disks under bus/block/devices.  If the disk name
133  *	contains slashes, name of driverfs node has them replaced with
134  *	bangs.  try_name() does the actual checks, assuming that driverfs
135  *	is mounted on rootfs /sys.
136  */
137 
138 dev_t name_to_dev_t(char *name)
139 {
140 	char s[32];
141 	char *p;
142 	dev_t res = 0;
143 	int part;
144 
145 #ifdef CONFIG_SYSFS
146 	int mkdir_err = sys_mkdir("/sys", 0700);
147 	if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
148 		goto out;
149 #endif
150 
151 	if (strncmp(name, "/dev/", 5) != 0) {
152 		unsigned maj, min;
153 
154 		if (sscanf(name, "%u:%u", &maj, &min) == 2) {
155 			res = MKDEV(maj, min);
156 			if (maj != MAJOR(res) || min != MINOR(res))
157 				goto fail;
158 		} else {
159 			res = new_decode_dev(simple_strtoul(name, &p, 16));
160 			if (*p)
161 				goto fail;
162 		}
163 		goto done;
164 	}
165 	name += 5;
166 	res = Root_NFS;
167 	if (strcmp(name, "nfs") == 0)
168 		goto done;
169 	res = Root_RAM0;
170 	if (strcmp(name, "ram") == 0)
171 		goto done;
172 
173 	if (strlen(name) > 31)
174 		goto fail;
175 	strcpy(s, name);
176 	for (p = s; *p; p++)
177 		if (*p == '/')
178 			*p = '!';
179 	res = try_name(s, 0);
180 	if (res)
181 		goto done;
182 
183 	while (p > s && isdigit(p[-1]))
184 		p--;
185 	if (p == s || !*p || *p == '0')
186 		goto fail;
187 	part = simple_strtoul(p, NULL, 10);
188 	*p = '\0';
189 	res = try_name(s, part);
190 	if (res)
191 		goto done;
192 
193 	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
194 		goto fail;
195 	p[-1] = '\0';
196 	res = try_name(s, part);
197 done:
198 #ifdef CONFIG_SYSFS
199 	sys_umount("/sys", 0);
200 out:
201 	if (!mkdir_err)
202 		sys_rmdir("/sys");
203 #endif
204 	return res;
205 fail:
206 	res = 0;
207 	goto done;
208 }
209 
210 static int __init root_dev_setup(char *line)
211 {
212 	strlcpy(saved_root_name, line, sizeof(saved_root_name));
213 	return 1;
214 }
215 
216 __setup("root=", root_dev_setup);
217 
218 static char * __initdata root_mount_data;
219 static int __init root_data_setup(char *str)
220 {
221 	root_mount_data = str;
222 	return 1;
223 }
224 
225 static char * __initdata root_fs_names;
226 static int __init fs_names_setup(char *str)
227 {
228 	root_fs_names = str;
229 	return 1;
230 }
231 
232 static unsigned int __initdata root_delay;
233 static int __init root_delay_setup(char *str)
234 {
235 	root_delay = simple_strtoul(str, NULL, 0);
236 	return 1;
237 }
238 
239 __setup("rootflags=", root_data_setup);
240 __setup("rootfstype=", fs_names_setup);
241 __setup("rootdelay=", root_delay_setup);
242 
243 static void __init get_fs_names(char *page)
244 {
245 	char *s = page;
246 
247 	if (root_fs_names) {
248 		strcpy(page, root_fs_names);
249 		while (*s++) {
250 			if (s[-1] == ',')
251 				s[-1] = '\0';
252 		}
253 	} else {
254 		int len = get_filesystem_list(page);
255 		char *p, *next;
256 
257 		page[len] = '\0';
258 		for (p = page-1; p; p = next) {
259 			next = strchr(++p, '\n');
260 			if (*p++ != '\t')
261 				continue;
262 			while ((*s++ = *p++) != '\n')
263 				;
264 			s[-1] = '\0';
265 		}
266 	}
267 	*s = '\0';
268 }
269 
270 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
271 {
272 	int err = sys_mount(name, "/root", fs, flags, data);
273 	if (err)
274 		return err;
275 
276 	sys_chdir("/root");
277 	ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
278 	printk("VFS: Mounted root (%s filesystem)%s.\n",
279 	       current->fs->pwdmnt->mnt_sb->s_type->name,
280 	       current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
281 	       " readonly" : "");
282 	return 0;
283 }
284 
285 void __init mount_block_root(char *name, int flags)
286 {
287 	char *fs_names = __getname();
288 	char *p;
289 	char b[BDEVNAME_SIZE];
290 
291 	get_fs_names(fs_names);
292 retry:
293 	for (p = fs_names; *p; p += strlen(p)+1) {
294 		int err = do_mount_root(name, p, flags, root_mount_data);
295 		switch (err) {
296 			case 0:
297 				goto out;
298 			case -EACCES:
299 				flags |= MS_RDONLY;
300 				goto retry;
301 			case -EINVAL:
302 				continue;
303 		}
304 	        /*
305 		 * Allow the user to distinguish between failed sys_open
306 		 * and bad superblock on root device.
307 		 */
308 		__bdevname(ROOT_DEV, b);
309 		printk("VFS: Cannot open root device \"%s\" or %s\n",
310 				root_device_name, b);
311 		printk("Please append a correct \"root=\" boot option\n");
312 
313 		panic("VFS: Unable to mount root fs on %s", b);
314 	}
315 	panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
316 out:
317 	putname(fs_names);
318 }
319 
320 #ifdef CONFIG_ROOT_NFS
321 static int __init mount_nfs_root(void)
322 {
323 	void *data = nfs_root_data();
324 
325 	create_dev("/dev/root", ROOT_DEV, NULL);
326 	if (data &&
327 	    do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
328 		return 1;
329 	return 0;
330 }
331 #endif
332 
333 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
334 void __init change_floppy(char *fmt, ...)
335 {
336 	struct termios termios;
337 	char buf[80];
338 	char c;
339 	int fd;
340 	va_list args;
341 	va_start(args, fmt);
342 	vsprintf(buf, fmt, args);
343 	va_end(args);
344 	fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
345 	if (fd >= 0) {
346 		sys_ioctl(fd, FDEJECT, 0);
347 		sys_close(fd);
348 	}
349 	printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
350 	fd = sys_open("/dev/console", O_RDWR, 0);
351 	if (fd >= 0) {
352 		sys_ioctl(fd, TCGETS, (long)&termios);
353 		termios.c_lflag &= ~ICANON;
354 		sys_ioctl(fd, TCSETSF, (long)&termios);
355 		sys_read(fd, &c, 1);
356 		termios.c_lflag |= ICANON;
357 		sys_ioctl(fd, TCSETSF, (long)&termios);
358 		sys_close(fd);
359 	}
360 }
361 #endif
362 
363 void __init mount_root(void)
364 {
365 #ifdef CONFIG_ROOT_NFS
366 	if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
367 		if (mount_nfs_root())
368 			return;
369 
370 		printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
371 		ROOT_DEV = Root_FD0;
372 	}
373 #endif
374 #ifdef CONFIG_BLK_DEV_FD
375 	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
376 		/* rd_doload is 2 for a dual initrd/ramload setup */
377 		if (rd_doload==2) {
378 			if (rd_load_disk(1)) {
379 				ROOT_DEV = Root_RAM1;
380 				root_device_name = NULL;
381 			}
382 		} else
383 			change_floppy("root floppy");
384 	}
385 #endif
386 	create_dev("/dev/root", ROOT_DEV, root_device_name);
387 	mount_block_root("/dev/root", root_mountflags);
388 }
389 
390 /*
391  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
392  */
393 void __init prepare_namespace(void)
394 {
395 	int is_floppy;
396 
397 	mount_devfs();
398 
399 	if (root_delay) {
400 		printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
401 		       root_delay);
402 		ssleep(root_delay);
403 	}
404 
405 	md_run_setup();
406 
407 	if (saved_root_name[0]) {
408 		root_device_name = saved_root_name;
409 		ROOT_DEV = name_to_dev_t(root_device_name);
410 		if (strncmp(root_device_name, "/dev/", 5) == 0)
411 			root_device_name += 5;
412 	}
413 
414 	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
415 
416 	if (initrd_load())
417 		goto out;
418 
419 	if (is_floppy && rd_doload && rd_load_disk(0))
420 		ROOT_DEV = Root_RAM0;
421 
422 	mount_root();
423 out:
424 	umount_devfs("/dev");
425 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
426 	sys_chroot(".");
427 	security_sb_post_mountroot();
428 	mount_devfs_fs ();
429 }
430 
431