xref: /openbmc/linux/init/do_mounts.c (revision 87c2ce3b)
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/mount.h>
11 
12 #include <linux/nfs_fs.h>
13 #include <linux/nfs_fs_sb.h>
14 #include <linux/nfs_mount.h>
15 
16 #include "do_mounts.h"
17 
18 extern int get_filesystem_list(char * buf);
19 
20 int __initdata rd_doload;	/* 1 = load RAM disk, 0 = don't load */
21 
22 int root_mountflags = MS_RDONLY | MS_VERBOSE;
23 char * __initdata root_device_name;
24 static char __initdata saved_root_name[64];
25 
26 /* this is initialized in init/main.c */
27 dev_t ROOT_DEV;
28 
29 static int __init load_ramdisk(char *str)
30 {
31 	rd_doload = simple_strtol(str,NULL,0) & 3;
32 	return 1;
33 }
34 __setup("load_ramdisk=", load_ramdisk);
35 
36 static int __init readonly(char *str)
37 {
38 	if (*str)
39 		return 0;
40 	root_mountflags |= MS_RDONLY;
41 	return 1;
42 }
43 
44 static int __init readwrite(char *str)
45 {
46 	if (*str)
47 		return 0;
48 	root_mountflags &= ~MS_RDONLY;
49 	return 1;
50 }
51 
52 __setup("ro", readonly);
53 __setup("rw", readwrite);
54 
55 static dev_t try_name(char *name, int part)
56 {
57 	char path[64];
58 	char buf[32];
59 	int range;
60 	dev_t res;
61 	char *s;
62 	int len;
63 	int fd;
64 	unsigned int maj, min;
65 
66 	/* read device number from .../dev */
67 
68 	sprintf(path, "/sys/block/%s/dev", name);
69 	fd = sys_open(path, 0, 0);
70 	if (fd < 0)
71 		goto fail;
72 	len = sys_read(fd, buf, 32);
73 	sys_close(fd);
74 	if (len <= 0 || len == 32 || buf[len - 1] != '\n')
75 		goto fail;
76 	buf[len - 1] = '\0';
77 	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
78 		/*
79 		 * Try the %u:%u format -- see print_dev_t()
80 		 */
81 		res = MKDEV(maj, min);
82 		if (maj != MAJOR(res) || min != MINOR(res))
83 			goto fail;
84 	} else {
85 		/*
86 		 * Nope.  Try old-style "0321"
87 		 */
88 		res = new_decode_dev(simple_strtoul(buf, &s, 16));
89 		if (*s)
90 			goto fail;
91 	}
92 
93 	/* if it's there and we are not looking for a partition - that's it */
94 	if (!part)
95 		return res;
96 
97 	/* otherwise read range from .../range */
98 	sprintf(path, "/sys/block/%s/range", name);
99 	fd = sys_open(path, 0, 0);
100 	if (fd < 0)
101 		goto fail;
102 	len = sys_read(fd, buf, 32);
103 	sys_close(fd);
104 	if (len <= 0 || len == 32 || buf[len - 1] != '\n')
105 		goto fail;
106 	buf[len - 1] = '\0';
107 	range = simple_strtoul(buf, &s, 10);
108 	if (*s)
109 		goto fail;
110 
111 	/* if partition is within range - we got it */
112 	if (part < range)
113 		return res + part;
114 fail:
115 	return 0;
116 }
117 
118 /*
119  *	Convert a name into device number.  We accept the following variants:
120  *
121  *	1) device number in hexadecimal	represents itself
122  *	2) /dev/nfs represents Root_NFS (0xff)
123  *	3) /dev/<disk_name> represents the device number of disk
124  *	4) /dev/<disk_name><decimal> represents the device number
125  *         of partition - device number of disk plus the partition number
126  *	5) /dev/<disk_name>p<decimal> - same as the above, that form is
127  *	   used when disk name of partitioned disk ends on a digit.
128  *
129  *	If name doesn't have fall into the categories above, we return 0.
130  *	Sysfs is used to check if something is a disk name - it has
131  *	all known disks under bus/block/devices.  If the disk name
132  *	contains slashes, name of sysfs node has them replaced with
133  *	bangs.  try_name() does the actual checks, assuming that sysfs
134  *	is mounted on rootfs /sys.
135  */
136 
137 dev_t name_to_dev_t(char *name)
138 {
139 	char s[32];
140 	char *p;
141 	dev_t res = 0;
142 	int part;
143 
144 #ifdef CONFIG_SYSFS
145 	int mkdir_err = sys_mkdir("/sys", 0700);
146 	if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
147 		goto out;
148 #endif
149 
150 	if (strncmp(name, "/dev/", 5) != 0) {
151 		unsigned maj, min;
152 
153 		if (sscanf(name, "%u:%u", &maj, &min) == 2) {
154 			res = MKDEV(maj, min);
155 			if (maj != MAJOR(res) || min != MINOR(res))
156 				goto fail;
157 		} else {
158 			res = new_decode_dev(simple_strtoul(name, &p, 16));
159 			if (*p)
160 				goto fail;
161 		}
162 		goto done;
163 	}
164 	name += 5;
165 	res = Root_NFS;
166 	if (strcmp(name, "nfs") == 0)
167 		goto done;
168 	res = Root_RAM0;
169 	if (strcmp(name, "ram") == 0)
170 		goto done;
171 
172 	if (strlen(name) > 31)
173 		goto fail;
174 	strcpy(s, name);
175 	for (p = s; *p; p++)
176 		if (*p == '/')
177 			*p = '!';
178 	res = try_name(s, 0);
179 	if (res)
180 		goto done;
181 
182 	while (p > s && isdigit(p[-1]))
183 		p--;
184 	if (p == s || !*p || *p == '0')
185 		goto fail;
186 	part = simple_strtoul(p, NULL, 10);
187 	*p = '\0';
188 	res = try_name(s, part);
189 	if (res)
190 		goto done;
191 
192 	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
193 		goto fail;
194 	p[-1] = '\0';
195 	res = try_name(s, part);
196 done:
197 #ifdef CONFIG_SYSFS
198 	sys_umount("/sys", 0);
199 out:
200 	if (!mkdir_err)
201 		sys_rmdir("/sys");
202 #endif
203 	return res;
204 fail:
205 	res = 0;
206 	goto done;
207 }
208 
209 static int __init root_dev_setup(char *line)
210 {
211 	strlcpy(saved_root_name, line, sizeof(saved_root_name));
212 	return 1;
213 }
214 
215 __setup("root=", root_dev_setup);
216 
217 static char * __initdata root_mount_data;
218 static int __init root_data_setup(char *str)
219 {
220 	root_mount_data = str;
221 	return 1;
222 }
223 
224 static char * __initdata root_fs_names;
225 static int __init fs_names_setup(char *str)
226 {
227 	root_fs_names = str;
228 	return 1;
229 }
230 
231 static unsigned int __initdata root_delay;
232 static int __init root_delay_setup(char *str)
233 {
234 	root_delay = simple_strtoul(str, NULL, 0);
235 	return 1;
236 }
237 
238 __setup("rootflags=", root_data_setup);
239 __setup("rootfstype=", fs_names_setup);
240 __setup("rootdelay=", root_delay_setup);
241 
242 static void __init get_fs_names(char *page)
243 {
244 	char *s = page;
245 
246 	if (root_fs_names) {
247 		strcpy(page, root_fs_names);
248 		while (*s++) {
249 			if (s[-1] == ',')
250 				s[-1] = '\0';
251 		}
252 	} else {
253 		int len = get_filesystem_list(page);
254 		char *p, *next;
255 
256 		page[len] = '\0';
257 		for (p = page-1; p; p = next) {
258 			next = strchr(++p, '\n');
259 			if (*p++ != '\t')
260 				continue;
261 			while ((*s++ = *p++) != '\n')
262 				;
263 			s[-1] = '\0';
264 		}
265 	}
266 	*s = '\0';
267 }
268 
269 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
270 {
271 	int err = sys_mount(name, "/root", fs, flags, data);
272 	if (err)
273 		return err;
274 
275 	sys_chdir("/root");
276 	ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
277 	printk("VFS: Mounted root (%s filesystem)%s.\n",
278 	       current->fs->pwdmnt->mnt_sb->s_type->name,
279 	       current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
280 	       " readonly" : "");
281 	return 0;
282 }
283 
284 void __init mount_block_root(char *name, int flags)
285 {
286 	char *fs_names = __getname();
287 	char *p;
288 	char b[BDEVNAME_SIZE];
289 
290 	get_fs_names(fs_names);
291 retry:
292 	for (p = fs_names; *p; p += strlen(p)+1) {
293 		int err = do_mount_root(name, p, flags, root_mount_data);
294 		switch (err) {
295 			case 0:
296 				goto out;
297 			case -EACCES:
298 				flags |= MS_RDONLY;
299 				goto retry;
300 			case -EINVAL:
301 				continue;
302 		}
303 	        /*
304 		 * Allow the user to distinguish between failed sys_open
305 		 * and bad superblock on root device.
306 		 */
307 		__bdevname(ROOT_DEV, b);
308 		printk("VFS: Cannot open root device \"%s\" or %s\n",
309 				root_device_name, b);
310 		printk("Please append a correct \"root=\" boot option\n");
311 
312 		panic("VFS: Unable to mount root fs on %s", b);
313 	}
314 	panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
315 out:
316 	putname(fs_names);
317 }
318 
319 #ifdef CONFIG_ROOT_NFS
320 static int __init mount_nfs_root(void)
321 {
322 	void *data = nfs_root_data();
323 
324 	create_dev("/dev/root", ROOT_DEV, NULL);
325 	if (data &&
326 	    do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
327 		return 1;
328 	return 0;
329 }
330 #endif
331 
332 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
333 void __init change_floppy(char *fmt, ...)
334 {
335 	struct termios termios;
336 	char buf[80];
337 	char c;
338 	int fd;
339 	va_list args;
340 	va_start(args, fmt);
341 	vsprintf(buf, fmt, args);
342 	va_end(args);
343 	fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
344 	if (fd >= 0) {
345 		sys_ioctl(fd, FDEJECT, 0);
346 		sys_close(fd);
347 	}
348 	printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
349 	fd = sys_open("/dev/console", O_RDWR, 0);
350 	if (fd >= 0) {
351 		sys_ioctl(fd, TCGETS, (long)&termios);
352 		termios.c_lflag &= ~ICANON;
353 		sys_ioctl(fd, TCSETSF, (long)&termios);
354 		sys_read(fd, &c, 1);
355 		termios.c_lflag |= ICANON;
356 		sys_ioctl(fd, TCSETSF, (long)&termios);
357 		sys_close(fd);
358 	}
359 }
360 #endif
361 
362 void __init mount_root(void)
363 {
364 #ifdef CONFIG_ROOT_NFS
365 	if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
366 		if (mount_nfs_root())
367 			return;
368 
369 		printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
370 		ROOT_DEV = Root_FD0;
371 	}
372 #endif
373 #ifdef CONFIG_BLK_DEV_FD
374 	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
375 		/* rd_doload is 2 for a dual initrd/ramload setup */
376 		if (rd_doload==2) {
377 			if (rd_load_disk(1)) {
378 				ROOT_DEV = Root_RAM1;
379 				root_device_name = NULL;
380 			}
381 		} else
382 			change_floppy("root floppy");
383 	}
384 #endif
385 	create_dev("/dev/root", ROOT_DEV, root_device_name);
386 	mount_block_root("/dev/root", root_mountflags);
387 }
388 
389 /*
390  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
391  */
392 void __init prepare_namespace(void)
393 {
394 	int is_floppy;
395 
396 	mount_devfs();
397 
398 	if (root_delay) {
399 		printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
400 		       root_delay);
401 		ssleep(root_delay);
402 	}
403 
404 	md_run_setup();
405 
406 	if (saved_root_name[0]) {
407 		root_device_name = saved_root_name;
408 		ROOT_DEV = name_to_dev_t(root_device_name);
409 		if (strncmp(root_device_name, "/dev/", 5) == 0)
410 			root_device_name += 5;
411 	}
412 
413 	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
414 
415 	if (initrd_load())
416 		goto out;
417 
418 	if (is_floppy && rd_doload && rd_load_disk(0))
419 		ROOT_DEV = Root_RAM0;
420 
421 	mount_root();
422 out:
423 	umount_devfs("/dev");
424 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
425 	sys_chroot(".");
426 	security_sb_post_mountroot();
427 	mount_devfs_fs ();
428 }
429 
430