xref: /openbmc/linux/init/do_mounts.c (revision b627b4ed)
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 #include <linux/initrd.h>
16 #include <linux/async.h>
17 #include <linux/fs_struct.h>
18 
19 #include <linux/nfs_fs.h>
20 #include <linux/nfs_fs_sb.h>
21 #include <linux/nfs_mount.h>
22 
23 #include "do_mounts.h"
24 
25 int __initdata rd_doload;	/* 1 = load RAM disk, 0 = don't load */
26 
27 int root_mountflags = MS_RDONLY | MS_SILENT;
28 static char * __initdata root_device_name;
29 static char __initdata saved_root_name[64];
30 static int __initdata root_wait;
31 
32 dev_t ROOT_DEV;
33 
34 static int __init load_ramdisk(char *str)
35 {
36 	rd_doload = simple_strtol(str,NULL,0) & 3;
37 	return 1;
38 }
39 __setup("load_ramdisk=", load_ramdisk);
40 
41 static int __init readonly(char *str)
42 {
43 	if (*str)
44 		return 0;
45 	root_mountflags |= MS_RDONLY;
46 	return 1;
47 }
48 
49 static int __init readwrite(char *str)
50 {
51 	if (*str)
52 		return 0;
53 	root_mountflags &= ~MS_RDONLY;
54 	return 1;
55 }
56 
57 __setup("ro", readonly);
58 __setup("rw", readwrite);
59 
60 /*
61  *	Convert a name into device number.  We accept the following variants:
62  *
63  *	1) device number in hexadecimal	represents itself
64  *	2) /dev/nfs represents Root_NFS (0xff)
65  *	3) /dev/<disk_name> represents the device number of disk
66  *	4) /dev/<disk_name><decimal> represents the device number
67  *         of partition - device number of disk plus the partition number
68  *	5) /dev/<disk_name>p<decimal> - same as the above, that form is
69  *	   used when disk name of partitioned disk ends on a digit.
70  *
71  *	If name doesn't have fall into the categories above, we return (0,0).
72  *	block_class is used to check if something is a disk name. If the disk
73  *	name contains slashes, the device name has them replaced with
74  *	bangs.
75  */
76 
77 dev_t name_to_dev_t(char *name)
78 {
79 	char s[32];
80 	char *p;
81 	dev_t res = 0;
82 	int part;
83 
84 	if (strncmp(name, "/dev/", 5) != 0) {
85 		unsigned maj, min;
86 
87 		if (sscanf(name, "%u:%u", &maj, &min) == 2) {
88 			res = MKDEV(maj, min);
89 			if (maj != MAJOR(res) || min != MINOR(res))
90 				goto fail;
91 		} else {
92 			res = new_decode_dev(simple_strtoul(name, &p, 16));
93 			if (*p)
94 				goto fail;
95 		}
96 		goto done;
97 	}
98 
99 	name += 5;
100 	res = Root_NFS;
101 	if (strcmp(name, "nfs") == 0)
102 		goto done;
103 	res = Root_RAM0;
104 	if (strcmp(name, "ram") == 0)
105 		goto done;
106 
107 	if (strlen(name) > 31)
108 		goto fail;
109 	strcpy(s, name);
110 	for (p = s; *p; p++)
111 		if (*p == '/')
112 			*p = '!';
113 	res = blk_lookup_devt(s, 0);
114 	if (res)
115 		goto done;
116 
117 	/*
118 	 * try non-existant, but valid partition, which may only exist
119 	 * after revalidating the disk, like partitioned md devices
120 	 */
121 	while (p > s && isdigit(p[-1]))
122 		p--;
123 	if (p == s || !*p || *p == '0')
124 		goto fail;
125 
126 	/* try disk name without <part number> */
127 	part = simple_strtoul(p, NULL, 10);
128 	*p = '\0';
129 	res = blk_lookup_devt(s, part);
130 	if (res)
131 		goto done;
132 
133 	/* try disk name without p<part number> */
134 	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
135 		goto fail;
136 	p[-1] = '\0';
137 	res = blk_lookup_devt(s, part);
138 	if (res)
139 		goto done;
140 
141 fail:
142 	return 0;
143 done:
144 	return res;
145 }
146 
147 static int __init root_dev_setup(char *line)
148 {
149 	strlcpy(saved_root_name, line, sizeof(saved_root_name));
150 	return 1;
151 }
152 
153 __setup("root=", root_dev_setup);
154 
155 static int __init rootwait_setup(char *str)
156 {
157 	if (*str)
158 		return 0;
159 	root_wait = 1;
160 	return 1;
161 }
162 
163 __setup("rootwait", rootwait_setup);
164 
165 static char * __initdata root_mount_data;
166 static int __init root_data_setup(char *str)
167 {
168 	root_mount_data = str;
169 	return 1;
170 }
171 
172 static char * __initdata root_fs_names;
173 static int __init fs_names_setup(char *str)
174 {
175 	root_fs_names = str;
176 	return 1;
177 }
178 
179 static unsigned int __initdata root_delay;
180 static int __init root_delay_setup(char *str)
181 {
182 	root_delay = simple_strtoul(str, NULL, 0);
183 	return 1;
184 }
185 
186 __setup("rootflags=", root_data_setup);
187 __setup("rootfstype=", fs_names_setup);
188 __setup("rootdelay=", root_delay_setup);
189 
190 static void __init get_fs_names(char *page)
191 {
192 	char *s = page;
193 
194 	if (root_fs_names) {
195 		strcpy(page, root_fs_names);
196 		while (*s++) {
197 			if (s[-1] == ',')
198 				s[-1] = '\0';
199 		}
200 	} else {
201 		int len = get_filesystem_list(page);
202 		char *p, *next;
203 
204 		page[len] = '\0';
205 		for (p = page-1; p; p = next) {
206 			next = strchr(++p, '\n');
207 			if (*p++ != '\t')
208 				continue;
209 			while ((*s++ = *p++) != '\n')
210 				;
211 			s[-1] = '\0';
212 		}
213 	}
214 	*s = '\0';
215 }
216 
217 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
218 {
219 	int err = sys_mount(name, "/root", fs, flags, data);
220 	if (err)
221 		return err;
222 
223 	sys_chdir("/root");
224 	ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
225 	printk("VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
226 	       current->fs->pwd.mnt->mnt_sb->s_type->name,
227 	       current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
228 	       " readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
229 	return 0;
230 }
231 
232 void __init mount_block_root(char *name, int flags)
233 {
234 	char *fs_names = __getname();
235 	char *p;
236 #ifdef CONFIG_BLOCK
237 	char b[BDEVNAME_SIZE];
238 #else
239 	const char *b = name;
240 #endif
241 
242 	get_fs_names(fs_names);
243 retry:
244 	for (p = fs_names; *p; p += strlen(p)+1) {
245 		int err = do_mount_root(name, p, flags, root_mount_data);
246 		switch (err) {
247 			case 0:
248 				goto out;
249 			case -EACCES:
250 				flags |= MS_RDONLY;
251 				goto retry;
252 			case -EINVAL:
253 				continue;
254 		}
255 	        /*
256 		 * Allow the user to distinguish between failed sys_open
257 		 * and bad superblock on root device.
258 		 * and give them a list of the available devices
259 		 */
260 #ifdef CONFIG_BLOCK
261 		__bdevname(ROOT_DEV, b);
262 #endif
263 		printk("VFS: Cannot open root device \"%s\" or %s\n",
264 				root_device_name, b);
265 		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
266 
267 		printk_all_partitions();
268 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
269 		printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
270 		       "explicit textual name for \"root=\" boot option.\n");
271 #endif
272 		panic("VFS: Unable to mount root fs on %s", b);
273 	}
274 
275 	printk("List of all partitions:\n");
276 	printk_all_partitions();
277 	printk("No filesystem could mount root, tried: ");
278 	for (p = fs_names; *p; p += strlen(p)+1)
279 		printk(" %s", p);
280 	printk("\n");
281 #ifdef CONFIG_BLOCK
282 	__bdevname(ROOT_DEV, b);
283 #endif
284 	panic("VFS: Unable to mount root fs on %s", b);
285 out:
286 	putname(fs_names);
287 }
288 
289 #ifdef CONFIG_ROOT_NFS
290 static int __init mount_nfs_root(void)
291 {
292 	void *data = nfs_root_data();
293 
294 	create_dev("/dev/root", ROOT_DEV);
295 	if (data &&
296 	    do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
297 		return 1;
298 	return 0;
299 }
300 #endif
301 
302 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
303 void __init change_floppy(char *fmt, ...)
304 {
305 	struct termios termios;
306 	char buf[80];
307 	char c;
308 	int fd;
309 	va_list args;
310 	va_start(args, fmt);
311 	vsprintf(buf, fmt, args);
312 	va_end(args);
313 	fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
314 	if (fd >= 0) {
315 		sys_ioctl(fd, FDEJECT, 0);
316 		sys_close(fd);
317 	}
318 	printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
319 	fd = sys_open("/dev/console", O_RDWR, 0);
320 	if (fd >= 0) {
321 		sys_ioctl(fd, TCGETS, (long)&termios);
322 		termios.c_lflag &= ~ICANON;
323 		sys_ioctl(fd, TCSETSF, (long)&termios);
324 		sys_read(fd, &c, 1);
325 		termios.c_lflag |= ICANON;
326 		sys_ioctl(fd, TCSETSF, (long)&termios);
327 		sys_close(fd);
328 	}
329 }
330 #endif
331 
332 void __init mount_root(void)
333 {
334 #ifdef CONFIG_ROOT_NFS
335 	if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
336 		if (mount_nfs_root())
337 			return;
338 
339 		printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
340 		ROOT_DEV = Root_FD0;
341 	}
342 #endif
343 #ifdef CONFIG_BLK_DEV_FD
344 	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
345 		/* rd_doload is 2 for a dual initrd/ramload setup */
346 		if (rd_doload==2) {
347 			if (rd_load_disk(1)) {
348 				ROOT_DEV = Root_RAM1;
349 				root_device_name = NULL;
350 			}
351 		} else
352 			change_floppy("root floppy");
353 	}
354 #endif
355 #ifdef CONFIG_BLOCK
356 	create_dev("/dev/root", ROOT_DEV);
357 	mount_block_root("/dev/root", root_mountflags);
358 #endif
359 }
360 
361 /*
362  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
363  */
364 void __init prepare_namespace(void)
365 {
366 	int is_floppy;
367 
368 	if (root_delay) {
369 		printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
370 		       root_delay);
371 		ssleep(root_delay);
372 	}
373 
374 	/*
375 	 * wait for the known devices to complete their probing
376 	 *
377 	 * Note: this is a potential source of long boot delays.
378 	 * For example, it is not atypical to wait 5 seconds here
379 	 * for the touchpad of a laptop to initialize.
380 	 */
381 	wait_for_device_probe();
382 
383 	md_run_setup();
384 
385 	if (saved_root_name[0]) {
386 		root_device_name = saved_root_name;
387 		if (!strncmp(root_device_name, "mtd", 3) ||
388 		    !strncmp(root_device_name, "ubi", 3)) {
389 			mount_block_root(root_device_name, root_mountflags);
390 			goto out;
391 		}
392 		ROOT_DEV = name_to_dev_t(root_device_name);
393 		if (strncmp(root_device_name, "/dev/", 5) == 0)
394 			root_device_name += 5;
395 	}
396 
397 	if (initrd_load())
398 		goto out;
399 
400 	/* wait for any asynchronous scanning to complete */
401 	if ((ROOT_DEV == 0) && root_wait) {
402 		printk(KERN_INFO "Waiting for root device %s...\n",
403 			saved_root_name);
404 		while (driver_probe_done() != 0 ||
405 			(ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
406 			msleep(100);
407 		async_synchronize_full();
408 	}
409 
410 	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
411 
412 	if (is_floppy && rd_doload && rd_load_disk(0))
413 		ROOT_DEV = Root_RAM0;
414 
415 	mount_root();
416 out:
417 	sys_mount(".", "/", NULL, MS_MOVE, NULL);
418 	sys_chroot(".");
419 }
420 
421