projects/linux·blob v2.6.13 · refs

429 lines · 9.1 KiB

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
18extern int get_filesystem_list(char * buf);
19
20int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
21
22int root_mountflags = MS_RDONLY | MS_VERBOSE;
23char * __initdata root_device_name;
24static char __initdata saved_root_name[64];
25
26/* this is initialized in init/main.c */
27dev_t ROOT_DEV;
28
29static 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
36static int __init readonly(char *str)
37{
38 if (*str)
39 return 0;
40 root_mountflags |= MS_RDONLY;
41 return 1;
42}
43
44static 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
55static 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;
114fail:
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 * Driverfs 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 driverfs node has them replaced with
133 * bangs. try_name() does the actual checks, assuming that driverfs
134 * is mounted on rootfs /sys.
135 */
136
137dev_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);
196done:
197#ifdef CONFIG_SYSFS
198 sys_umount("/sys", 0);
199out:
200 if (!mkdir_err)
201 sys_rmdir("/sys");
202#endif
203 return res;
204fail:
205 res = 0;
206 goto done;
207}
208
209static 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
217static char * __initdata root_mount_data;
218static int __init root_data_setup(char *str)
219{
220 root_mount_data = str;
221 return 1;
222}
223
224static char * __initdata root_fs_names;
225static int __init fs_names_setup(char *str)
226{
227 root_fs_names = str;
228 return 1;
229}
230
231static unsigned int __initdata root_delay;
232static 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
242static 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
269static 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
284void __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);
291retry:
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));
315out:
316 putname(fs_names);
317}
318
319#ifdef CONFIG_ROOT_NFS
320static 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)
333void __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
362void __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 */
392void __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();
422out:
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