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/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_SILENT;
  23 char * __initdata root_device_name;
  24 static char __initdata saved_root_name[64];
  25
  26 dev_t ROOT_DEV;
  27
  28 static int __init load_ramdisk(char *str)
  29 {
  30         rd_doload = simple_strtol(str,NULL,0) & 3;
  31         return 1;
  32 }
  33 __setup("load_ramdisk=", load_ramdisk);
  34
  35 static int __init readonly(char *str)
  36 {
  37         if (*str)
  38                 return 0;
  39         root_mountflags |= MS_RDONLY;
  40         return 1;
  41 }
  42
  43 static int __init readwrite(char *str)
  44 {
  45         if (*str)
  46                 return 0;
  47         root_mountflags &= ~MS_RDONLY;
  48         return 1;
  49 }
  50
  51 __setup("ro", readonly);
  52 __setup("rw", readwrite);
  53
  54 static dev_t try_name(char *name, int part)
  55 {
  56         char path[64];
  57         char buf[32];
  58         int range;
  59         dev_t res;
  60         char *s;
  61         int len;
  62         int fd;
  63         unsigned int maj, min;
  64
  65         /* read device number from .../dev */
  66
  67         sprintf(path, "/sys/block/%s/dev", name);
  68         fd = sys_open(path, 0, 0);
  69         if (fd < 0)
  70                 goto fail;
  71         len = sys_read(fd, buf, 32);
  72         sys_close(fd);
  73         if (len <= 0 || len == 32 || buf[len - 1] != '\n')
  74                 goto fail;
  75         buf[len - 1] = '\0';
  76         if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
  77                 /*
  78                  * Try the %u:%u format -- see print_dev_t()
  79                  */
  80                 res = MKDEV(maj, min);
  81                 if (maj != MAJOR(res) || min != MINOR(res))
  82                         goto fail;
  83         } else {
  84                 /*
  85                  * Nope.  Try old-style "0321"
  86                  */
  87                 res = new_decode_dev(simple_strtoul(buf, &s, 16));
  88                 if (*s)
  89                         goto fail;
  90         }
  91
  92         /* if it's there and we are not looking for a partition - that's it */
  93         if (!part)
  94                 return res;
  95
  96         /* otherwise read range from .../range */
  97         sprintf(path, "/sys/block/%s/range", name);
  98         fd = sys_open(path, 0, 0);
  99         if (fd < 0)
 100                 goto fail;
 101         len = sys_read(fd, buf, 32);
 102         sys_close(fd);
 103         if (len <= 0 || len == 32 || buf[len - 1] != '\n')
 104                 goto fail;
 105         buf[len - 1] = '\0';
 106         range = simple_strtoul(buf, &s, 10);
 107         if (*s)
 108                 goto fail;
 109
 110         /* if partition is within range - we got it */
 111         if (part < range)
 112                 return res + part;
 113 fail:
 114         return 0;
 115 }
 116
 117 /*
 118  *      Convert a name into device number.  We accept the following variants:
 119  *
 120  *      1) device number in hexadecimal represents itself
 121  *      2) /dev/nfs represents Root_NFS (0xff)
 122  *      3) /dev/<disk_name> represents the device number of disk
 123  *      4) /dev/<disk_name><decimal> represents the device number
 124  *         of partition - device number of disk plus the partition number
 125  *      5) /dev/<disk_name>p<decimal> - same as the above, that form is
 126  *         used when disk name of partitioned disk ends on a digit.
 127  *
 128  *      If name doesn't have fall into the categories above, we return 0.
 129  *      Sysfs is used to check if something is a disk name - it has
 130  *      all known disks under bus/block/devices.  If the disk name
 131  *      contains slashes, name of sysfs node has them replaced with
 132  *      bangs.  try_name() does the actual checks, assuming that sysfs
 133  *      is mounted on rootfs /sys.
 134  */
 135
 136 dev_t name_to_dev_t(char *name)
 137 {
 138         char s[32];
 139         char *p;
 140         dev_t res = 0;
 141         int part;
 142
 143 #ifdef CONFIG_SYSFS
 144         int mkdir_err = sys_mkdir("/sys", 0700);
 145         if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
 146                 goto out;
 147 #endif
 148
 149         if (strncmp(name, "/dev/", 5) != 0) {
 150                 unsigned maj, min;
 151
 152                 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
 153                         res = MKDEV(maj, min);
 154                         if (maj != MAJOR(res) || min != MINOR(res))
 155                                 goto fail;
 156                 } else {
 157                         res = new_decode_dev(simple_strtoul(name, &p, 16));
 158                         if (*p)
 159                                 goto fail;
 160                 }
 161                 goto done;
 162         }
 163         name += 5;
 164         res = Root_NFS;
 165         if (strcmp(name, "nfs") == 0)
 166                 goto done;
 167         res = Root_RAM0;
 168         if (strcmp(name, "ram") == 0)
 169                 goto done;
 170
 171         if (strlen(name) > 31)
 172                 goto fail;
 173         strcpy(s, name);
 174         for (p = s; *p; p++)
 175                 if (*p == '/')
 176                         *p = '!';
 177         res = try_name(s, 0);
 178         if (res)
 179                 goto done;
 180
 181         while (p > s && isdigit(p[-1]))
 182                 p--;
 183         if (p == s || !*p || *p == '0')
 184                 goto fail;
 185         part = simple_strtoul(p, NULL, 10);
 186         *p = '\0';
 187         res = try_name(s, part);
 188         if (res)
 189                 goto done;
 190
 191         if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
 192                 goto fail;
 193         p[-1] = '\0';
 194         res = try_name(s, part);
 195 done:
 196 #ifdef CONFIG_SYSFS
 197         sys_umount("/sys", 0);
 198 out:
 199         if (!mkdir_err)
 200                 sys_rmdir("/sys");
 201 #endif
 202         return res;
 203 fail:
 204         res = 0;
 205         goto done;
 206 }
 207
 208 static int __init root_dev_setup(char *line)
 209 {
 210         strlcpy(saved_root_name, line, sizeof(saved_root_name));
 211         return 1;
 212 }
 213
 214 __setup("root=", root_dev_setup);
 215
 216 static char * __initdata root_mount_data;
 217 static int __init root_data_setup(char *str)
 218 {
 219         root_mount_data = str;
 220         return 1;
 221 }
 222
 223 static char * __initdata root_fs_names;
 224 static int __init fs_names_setup(char *str)
 225 {
 226         root_fs_names = str;
 227         return 1;
 228 }
 229
 230 static unsigned int __initdata root_delay;
 231 static int __init root_delay_setup(char *str)
 232 {
 233         root_delay = simple_strtoul(str, NULL, 0);
 234         return 1;
 235 }
 236
 237 __setup("rootflags=", root_data_setup);
 238 __setup("rootfstype=", fs_names_setup);
 239 __setup("rootdelay=", root_delay_setup);
 240
 241 static void __init get_fs_names(char *page)
 242 {
 243         char *s = page;
 244
 245         if (root_fs_names) {
 246                 strcpy(page, root_fs_names);
 247                 while (*s++) {
 248                         if (s[-1] == ',')
 249                                 s[-1] = '\0';
 250                 }
 251         } else {
 252                 int len = get_filesystem_list(page);
 253                 char *p, *next;
 254
 255                 page[len] = '\0';
 256                 for (p = page-1; p; p = next) {
 257                         next = strchr(++p, '\n');
 258                         if (*p++ != '\t')
 259                                 continue;
 260                         while ((*s++ = *p++) != '\n')
 261                                 ;
 262                         s[-1] = '\0';
 263                 }
 264         }
 265         *s = '\0';
 266 }
 267
 268 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 269 {
 270         int err = sys_mount(name, "/root", fs, flags, data);
 271         if (err)
 272                 return err;
 273
 274         sys_chdir("/root");
 275         ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
 276         printk("VFS: Mounted root (%s filesystem)%s.\n",
 277                current->fs->pwdmnt->mnt_sb->s_type->name,
 278                current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
 279                " readonly" : "");
 280         return 0;
 281 }
 282
 283 void __init mount_block_root(char *name, int flags)
 284 {
 285         char *fs_names = __getname();
 286         char *p;
 287         char b[BDEVNAME_SIZE];
 288
 289         get_fs_names(fs_names);
 290 retry:
 291         for (p = fs_names; *p; p += strlen(p)+1) {
 292                 int err = do_mount_root(name, p, flags, root_mount_data);
 293                 switch (err) {
 294                         case 0:
 295                                 goto out;
 296                         case -EACCES:
 297                                 flags |= MS_RDONLY;
 298                                 goto retry;
 299                         case -EINVAL:
 300                                 continue;
 301                 }
 302                 /*
 303                  * Allow the user to distinguish between failed sys_open
 304                  * and bad superblock on root device.
 305                  */
 306                 __bdevname(ROOT_DEV, b);
 307                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 308                                 root_device_name, b);
 309                 printk("Please append a correct \"root=\" boot option\n");
 310
 311                 panic("VFS: Unable to mount root fs on %s", b);
 312         }
 313
 314         printk("No filesystem could mount root, tried: ");
 315         for (p = fs_names; *p; p += strlen(p)+1)
 316                 printk(" %s", p);
 317         printk("\n");
 318         panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
 319 out:
 320         putname(fs_names);
 321 }
 322
 323 #ifdef CONFIG_ROOT_NFS
 324 static int __init mount_nfs_root(void)
 325 {
 326         void *data = nfs_root_data();
 327
 328         create_dev("/dev/root", ROOT_DEV);
 329         if (data &&
 330             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 331                 return 1;
 332         return 0;
 333 }
 334 #endif
 335
 336 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 337 void __init change_floppy(char *fmt, ...)
 338 {
 339         struct termios termios;
 340         char buf[80];
 341         char c;
 342         int fd;
 343         va_list args;
 344         va_start(args, fmt);
 345         vsprintf(buf, fmt, args);
 346         va_end(args);
 347         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 348         if (fd >= 0) {
 349                 sys_ioctl(fd, FDEJECT, 0);
 350                 sys_close(fd);
 351         }
 352         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 353         fd = sys_open("/dev/console", O_RDWR, 0);
 354         if (fd >= 0) {
 355                 sys_ioctl(fd, TCGETS, (long)&termios);
 356                 termios.c_lflag &= ~ICANON;
 357                 sys_ioctl(fd, TCSETSF, (long)&termios);
 358                 sys_read(fd, &c, 1);
 359                 termios.c_lflag |= ICANON;
 360                 sys_ioctl(fd, TCSETSF, (long)&termios);
 361                 sys_close(fd);
 362         }
 363 }
 364 #endif
 365
 366 void __init mount_root(void)
 367 {
 368 #ifdef CONFIG_ROOT_NFS
 369         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 370                 if (mount_nfs_root())
 371                         return;
 372
 373                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 374                 ROOT_DEV = Root_FD0;
 375         }
 376 #endif
 377 #ifdef CONFIG_BLK_DEV_FD
 378         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 379                 /* rd_doload is 2 for a dual initrd/ramload setup */
 380                 if (rd_doload==2) {
 381                         if (rd_load_disk(1)) {
 382                                 ROOT_DEV = Root_RAM1;
 383                                 root_device_name = NULL;
 384                         }
 385                 } else
 386                         change_floppy("root floppy");
 387         }
 388 #endif
 389         create_dev("/dev/root", ROOT_DEV);
 390         mount_block_root("/dev/root", root_mountflags);
 391 }
 392
 393 /*
 394  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 395  */
 396 void __init prepare_namespace(void)
 397 {
 398         int is_floppy;
 399
 400         if (root_delay) {
 401                 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
 402                        root_delay);
 403                 ssleep(root_delay);
 404         }
 405
 406         md_run_setup();
 407
 408         if (saved_root_name[0]) {
 409                 root_device_name = saved_root_name;
 410                 if (!strncmp(root_device_name, "mtd", 3)) {
 411                         mount_block_root(root_device_name, root_mountflags);
 412                         goto out;
 413                 }
 414                 ROOT_DEV = name_to_dev_t(root_device_name);
 415                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 416                         root_device_name += 5;
 417         }
 418
 419         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 420
 421         if (initrd_load())
 422                 goto out;
 423
 424         if (is_floppy && rd_doload && rd_load_disk(0))
 425                 ROOT_DEV = Root_RAM0;
 426
 427         mount_root();
 428 out:
 429         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 430         sys_chroot(".");
 431         security_sb_post_mountroot();
 432 }
 433