Root/init/do_mounts.c

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
25int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
26
27int root_mountflags = MS_RDONLY | MS_SILENT;
28static char * __initdata root_device_name;
29static char __initdata saved_root_name[64];
30static int __initdata root_wait;
31
32dev_t ROOT_DEV;
33
34static 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
41static int __init readonly(char *str)
42{
43    if (*str)
44        return 0;
45    root_mountflags |= MS_RDONLY;
46    return 1;
47}
48
49static 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
77dev_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
141fail:
142    return 0;
143done:
144    return res;
145}
146
147static 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
155static 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
165static char * __initdata root_mount_data;
166static int __init root_data_setup(char *str)
167{
168    root_mount_data = str;
169    return 1;
170}
171
172static char * __initdata root_fs_names;
173static int __init fs_names_setup(char *str)
174{
175    root_fs_names = str;
176    return 1;
177}
178
179static unsigned int __initdata root_delay;
180static 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
190static 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
217static 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
232void __init mount_block_root(char *name, int flags)
233{
234    char *fs_names = __getname_gfp(GFP_KERNEL
235        | __GFP_NOTRACK_FALSE_POSITIVE);
236    char *p;
237#ifdef CONFIG_BLOCK
238    char b[BDEVNAME_SIZE];
239#else
240    const char *b = name;
241#endif
242
243    get_fs_names(fs_names);
244retry:
245    for (p = fs_names; *p; p += strlen(p)+1) {
246        int err = do_mount_root(name, p, flags, root_mount_data);
247        switch (err) {
248            case 0:
249                goto out;
250            case -EACCES:
251                flags |= MS_RDONLY;
252                goto retry;
253            case -EINVAL:
254                continue;
255        }
256            /*
257         * Allow the user to distinguish between failed sys_open
258         * and bad superblock on root device.
259         * and give them a list of the available devices
260         */
261#ifdef CONFIG_BLOCK
262        __bdevname(ROOT_DEV, b);
263#endif
264        printk("VFS: Cannot open root device \"%s\" or %s\n",
265                root_device_name, b);
266        printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
267
268        printk_all_partitions();
269#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
270        printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
271               "explicit textual name for \"root=\" boot option.\n");
272#endif
273        panic("VFS: Unable to mount root fs on %s", b);
274    }
275
276    printk("List of all partitions:\n");
277    printk_all_partitions();
278    printk("No filesystem could mount root, tried: ");
279    for (p = fs_names; *p; p += strlen(p)+1)
280        printk(" %s", p);
281    printk("\n");
282#ifdef CONFIG_BLOCK
283    __bdevname(ROOT_DEV, b);
284#endif
285    panic("VFS: Unable to mount root fs on %s", b);
286out:
287    putname(fs_names);
288}
289 
290#ifdef CONFIG_ROOT_NFS
291static int __init mount_nfs_root(void)
292{
293    void *data = nfs_root_data();
294
295    create_dev("/dev/root", ROOT_DEV);
296    if (data &&
297        do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
298        return 1;
299    return 0;
300}
301#endif
302
303#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
304void __init change_floppy(char *fmt, ...)
305{
306    struct termios termios;
307    char buf[80];
308    char c;
309    int fd;
310    va_list args;
311    va_start(args, fmt);
312    vsprintf(buf, fmt, args);
313    va_end(args);
314    fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
315    if (fd >= 0) {
316        sys_ioctl(fd, FDEJECT, 0);
317        sys_close(fd);
318    }
319    printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
320    fd = sys_open("/dev/console", O_RDWR, 0);
321    if (fd >= 0) {
322        sys_ioctl(fd, TCGETS, (long)&termios);
323        termios.c_lflag &= ~ICANON;
324        sys_ioctl(fd, TCSETSF, (long)&termios);
325        sys_read(fd, &c, 1);
326        termios.c_lflag |= ICANON;
327        sys_ioctl(fd, TCSETSF, (long)&termios);
328        sys_close(fd);
329    }
330}
331#endif
332
333void __init mount_root(void)
334{
335#ifdef CONFIG_ROOT_NFS
336    if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
337        if (mount_nfs_root())
338            return;
339
340        printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
341        ROOT_DEV = Root_FD0;
342    }
343#endif
344#ifdef CONFIG_BLK_DEV_FD
345    if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
346        /* rd_doload is 2 for a dual initrd/ramload setup */
347        if (rd_doload==2) {
348            if (rd_load_disk(1)) {
349                ROOT_DEV = Root_RAM1;
350                root_device_name = NULL;
351            }
352        } else
353            change_floppy("root floppy");
354    }
355#endif
356#ifdef CONFIG_BLOCK
357    create_dev("/dev/root", ROOT_DEV);
358    mount_block_root("/dev/root", root_mountflags);
359#endif
360}
361
362/*
363 * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
364 */
365void __init prepare_namespace(void)
366{
367    int is_floppy;
368
369    if (root_delay) {
370        printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
371               root_delay);
372        ssleep(root_delay);
373    }
374
375    /*
376     * wait for the known devices to complete their probing
377     *
378     * Note: this is a potential source of long boot delays.
379     * For example, it is not atypical to wait 5 seconds here
380     * for the touchpad of a laptop to initialize.
381     */
382    wait_for_device_probe();
383
384    md_run_setup();
385
386    if (saved_root_name[0]) {
387        root_device_name = saved_root_name;
388        if (!strncmp(root_device_name, "mtd", 3) ||
389            !strncmp(root_device_name, "ubi", 3)) {
390            mount_block_root(root_device_name, root_mountflags);
391            goto out;
392        }
393        ROOT_DEV = name_to_dev_t(root_device_name);
394        if (strncmp(root_device_name, "/dev/", 5) == 0)
395            root_device_name += 5;
396    }
397
398    if (initrd_load())
399        goto out;
400
401    /* wait for any asynchronous scanning to complete */
402    if ((ROOT_DEV == 0) && root_wait) {
403        printk(KERN_INFO "Waiting for root device %s...\n",
404            saved_root_name);
405        while (driver_probe_done() != 0 ||
406            (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
407            msleep(100);
408        async_synchronize_full();
409    }
410
411    is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
412
413    if (is_floppy && rd_doload && rd_load_disk(0))
414        ROOT_DEV = Root_RAM0;
415
416    mount_root();
417out:
418    sys_mount(".", "/", NULL, MS_MOVE, NULL);
419    sys_chroot(".");
420}
421
422

Archive Download this file



interactive