xref: /openbmc/linux/init/do_mounts.c (revision f42b3800)
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 
16 #include <linux/nfs_fs.h>
17 #include <linux/nfs_fs_sb.h>
18 #include <linux/nfs_mount.h>
19 
20 #include "do_mounts.h"
21 
22 int __initdata rd_doload;	/* 1 = load RAM disk, 0 = don't load */
23 
24 int root_mountflags = MS_RDONLY | MS_SILENT;
25 char * __initdata root_device_name;
26 static char __initdata saved_root_name[64];
27 static int __initdata root_wait;
28 
29 dev_t ROOT_DEV;
30 
31 static int __init load_ramdisk(char *str)
32 {
33 	rd_doload = simple_strtol(str,NULL,0) & 3;
34 	return 1;
35 }
36 __setup("load_ramdisk=", load_ramdisk);
37 
38 static int __init readonly(char *str)
39 {
40 	if (*str)
41 		return 0;
42 	root_mountflags |= MS_RDONLY;
43 	return 1;
44 }
45 
46 static int __init readwrite(char *str)
47 {
48 	if (*str)
49 		return 0;
50 	root_mountflags &= ~MS_RDONLY;
51 	return 1;
52 }
53 
54 __setup("ro", readonly);
55 __setup("rw", readwrite);
56 
57 /*
58  *	Convert a name into device number.  We accept the following variants:
59  *
60  *	1) device number in hexadecimal	represents itself
61  *	2) /dev/nfs represents Root_NFS (0xff)
62  *	3) /dev/<disk_name> represents the device number of disk
63  *	4) /dev/<disk_name><decimal> represents the device number
64  *         of partition - device number of disk plus the partition number
65  *	5) /dev/<disk_name>p<decimal> - same as the above, that form is
66  *	   used when disk name of partitioned disk ends on a digit.
67  *
68  *	If name doesn't have fall into the categories above, we return (0,0).
69  *	block_class is used to check if something is a disk name. If the disk
70  *	name contains slashes, the device name has them replaced with
71  *	bangs.
72  */
73 
74 dev_t name_to_dev_t(char *name)
75 {
76 	char s[32];
77 	char *p;
78 	dev_t res = 0;
79 
80 	if (strncmp(name, "/dev/", 5) != 0) {
81 		unsigned maj, min;
82 
83 		if (sscanf(name, "%u:%u", &maj, &min) == 2) {
84 			res = MKDEV(maj, min);
85 			if (maj != MAJOR(res) || min != MINOR(res))
86 				goto fail;
87 		} else {
88 			res = new_decode_dev(simple_strtoul(name, &p, 16));
89 			if (*p)
90 				goto fail;
91 		}
92 		goto done;
93 	}
94 
95 	name += 5;
96 	res = Root_NFS;
97 	if (strcmp(name, "nfs") == 0)
98 		goto done;
99 	res = Root_RAM0;
100 	if (strcmp(name, "ram") == 0)
101 		goto done;
102 
103 	if (strlen(name) > 31)
104 		goto fail;
105 	strcpy(s, name);
106 	for (p = s; *p; p++)
107 		if (*p == '/')
108 			*p = '!';
109 	res = blk_lookup_devt(s);
110 	if (res)
111 		goto done;
112 
113 fail:
114 	return 0;
115 done:
116 	return res;
117 }
118 
119 static int __init root_dev_setup(char *line)
120 {
121 	strlcpy(saved_root_name, line, sizeof(saved_root_name));
122 	return 1;
123 }
124 
125 __setup("root=", root_dev_setup);
126 
127 static int __init rootwait_setup(char *str)
128 {
129 	if (*str)
130 		return 0;
131 	root_wait = 1;
132 	return 1;
133 }
134 
135 __setup("rootwait", rootwait_setup);
136 
137 static char * __initdata root_mount_data;
138 static int __init root_data_setup(char *str)
139 {
140 	root_mount_data = str;
141 	return 1;
142 }
143 
144 static char * __initdata root_fs_names;
145 static int __init fs_names_setup(char *str)
146 {
147 	root_fs_names = str;
148 	return 1;
149 }
150 
151 static unsigned int __initdata root_delay;
152 static int __init root_delay_setup(char *str)
153 {
154 	root_delay = simple_strtoul(str, NULL, 0);
155 	return 1;
156 }
157 
158 __setup("rootflags=", root_data_setup);
159 __setup("rootfstype=", fs_names_setup);
160 __setup("rootdelay=", root_delay_setup);
161 
162 static void __init get_fs_names(char *page)
163 {
164 	char *s = page;
165 
166 	if (root_fs_names) {
167 		strcpy(page, root_fs_names);
168 		while (*s++) {
169 			if (s[-1] == ',')
170 				s[-1] = '\0';
171 		}
172 	} else {
173 		int len = get_filesystem_list(page);
174 		char *p, *next;
175 
176 		page[len] = '\0';
177 		for (p = page-1; p; p = next) {
178 			next = strchr(++p, '\n');
179 			if (*p++ != '\t')
180 				continue;
181 			while ((*s++ = *p++) != '\n')
182 				;
183 			s[-1] = '\0';
184 		}
185 	}
186 	*s = '\0';
187 }
188 
189 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
190 {
191 	int err = sys_mount(name, "/root", fs, flags, data);
192 	if (err)
193 		return err;
194 
195 	sys_chdir("/root");
196 	ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
197 	printk("VFS: Mounted root (%s filesystem)%s.\n",
198 	       current->fs->pwd.mnt->mnt_sb->s_type->name,
199 	       current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
200 	       " readonly" : "");
201 	return 0;
202 }
203 
204 void __init mount_block_root(char *name, int flags)
205 {
206 	char *fs_names = __getname();
207 	char *p;
208 #ifdef CONFIG_BLOCK
209 	char b[BDEVNAME_SIZE];
210 #else
211 	const char *b = name;
212 #endif
213 
214 	get_fs_names(fs_names);
215 retry:
216 	for (p = fs_names; *p; p += strlen(p)+1) {
217 		int err = do_mount_root(name, p, flags, root_mount_data);
218 		switch (err) {
219 			case 0:
220 				goto out;
221 			case -EACCES:
222 				flags |= MS_RDONLY;
223 				goto retry;
224 			case -EINVAL:
225 				continue;
226 		}
227 	        /*
228 		 * Allow the user to distinguish between failed sys_open
229 		 * and bad superblock on root device.
230 		 * and give them a list of the available devices
231 		 */
232 #ifdef CONFIG_BLOCK
233 		__bdevname(ROOT_DEV, b);
234 #endif
235 		printk("VFS: Cannot open root device \"%s\" or %s\n",
236 				root_device_name, b);
237 		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
238 
239 		printk_all_partitions();
240 		panic("VFS: Unable to mount root fs on %s", b);
241 	}
242 
243 	printk("List of all partitions:\n");
244 	printk_all_partitions();
245 	printk("No filesystem could mount root, tried: ");
246 	for (p = fs_names; *p; p += strlen(p)+1)
247 		printk(" %s", p);
248 	printk("\n");
249 #ifdef CONFIG_BLOCK
250 	__bdevname(ROOT_DEV, b);
251 #endif
252 	panic("VFS: Unable to mount root fs on %s", b);
253 out:
254 	putname(fs_names);
255 }
256 
257 #ifdef CONFIG_ROOT_NFS
258 static int __init mount_nfs_root(void)
259 {
260 	void *data = nfs_root_data();
261 
262 	create_dev("/dev/root", ROOT_DEV);
263 	if (data &&
264 	    do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
265 		return 1;
266 	return 0;
267 }
268 #endif
269 
270 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
271 void __init change_floppy(char *fmt, ...)
272 {
273 	struct termios termios;
274 	char buf[80];
275 	char c;
276 	int fd;
277 	va_list args;
278 	va_start(args, fmt);
279 	vsprintf(buf, fmt, args);
280 	va_end(args);
281 	fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
282 	if (fd >= 0) {
283 		sys_ioctl(fd, FDEJECT, 0);
284 		sys_close(fd);
285 	}
286 	printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
287 	fd = sys_open("/dev/console", O_RDWR, 0);
288 	if (fd >= 0) {
289 		sys_ioctl(fd, TCGETS, (long)&termios);
290 		termios.c_lflag &= ~ICANON;
291 		sys_ioctl(fd, TCSETSF, (long)&termios);
292 		sys_read(fd, &c, 1);
293 		termios.c_lflag |= ICANON;
294 		sys_ioctl(fd, TCSETSF, (long)&termios);
295 		sys_close(fd);
296 	}
297 }
298 #endif
299 
300 void __init mount_root(void)
301 {
302 #ifdef CONFIG_ROOT_NFS
303 	if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
304 		if (mount_nfs_root())
305 			return;
306 
307 		printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
308 		ROOT_DEV = Root_FD0;
309 	}
310 #endif
311 #ifdef CONFIG_BLK_DEV_FD
312 	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
313 		/* rd_doload is 2 for a dual initrd/ramload setup */
314 		if (rd_doload==2) {
315 			if (rd_load_disk(1)) {
316 				ROOT_DEV = Root_RAM1;
317 				root_device_name = NULL;
318 			}
319 		} else
320 			change_floppy("root floppy");
321 	}
322 #endif
323 #ifdef CONFIG_BLOCK
324 	create_dev("/dev/root", ROOT_DEV);
325 	mount_block_root("/dev/root", root_mountflags);
326 #endif
327 }
328 
329 /*
330  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
331  */
332 void __init prepare_namespace(void)
333 {
334 	int is_floppy;
335 
336 	if (root_delay) {
337 		printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
338 		       root_delay);
339 		ssleep(root_delay);
340 	}
341 
342 	/* wait for the known devices to complete their probing */
343 	while (driver_probe_done() != 0)
344 		msleep(100);
345 
346 	md_run_setup();
347 
348 	if (saved_root_name[0]) {
349 		root_device_name = saved_root_name;
350 		if (!strncmp(root_device_name, "mtd", 3)) {
351 			mount_block_root(root_device_name, root_mountflags);
352 			goto out;
353 		}
354 		ROOT_DEV = name_to_dev_t(root_device_name);
355 		if (strncmp(root_device_name, "/dev/", 5) == 0)
356 			root_device_name += 5;
357 	}
358 
359 	if (initrd_load())
360 		goto out;
361 
362 	/* wait for any asynchronous scanning to complete */
363 	if ((ROOT_DEV == 0) && root_wait) {
364 		printk(KERN_INFO "Waiting for root device %s...\n",
365 			saved_root_name);
366 		while (driver_probe_done() != 0 ||
367 			(ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
368 			msleep(100);
369 	}
370 
371 	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
372 
373 	if (is_floppy && rd_doload && rd_load_disk(0))
374 		ROOT_DEV = Root_RAM0;
375 
376 	mount_root();
377 out:
378 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
379 	sys_chroot(".");
380 }
381 
382