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 #include <linux/device.h>
  12
  13 #include <linux/nfs_fs.h>
  14 #include <linux/nfs_fs_sb.h>
  15 #include <linux/nfs_mount.h>
  16
  17 #include "do_mounts.h"
  18
  19 extern int get_filesystem_list(char * buf);
  20
  21 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  22
  23 int root_mountflags = MS_RDONLY | MS_SILENT;
  24 char * __initdata root_device_name;
  25 static char __initdata saved_root_name[64];
  26
  27 dev_t ROOT_DEV;
  28
  29 static 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
  36 static int __init readonly(char *str)
  37 {
  38         if (*str)
  39                 return 0;
  40         root_mountflags |= MS_RDONLY;
  41         return 1;
  42 }
  43
  44 static 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
  55 static 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;
 114 fail:
 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  *      Sysfs 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 sysfs node has them replaced with
 133  *      bangs.  try_name() does the actual checks, assuming that sysfs
 134  *      is mounted on rootfs /sys.
 135  */
 136
 137 dev_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);
 196 done:
 197 #ifdef CONFIG_SYSFS
 198         sys_umount("/sys", 0);
 199 out:
 200         if (!mkdir_err)
 201                 sys_rmdir("/sys");
 202 #endif
 203         return res;
 204 fail:
 205         res = 0;
 206         goto done;
 207 }
 208
 209 static 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
 217 static char * __initdata root_mount_data;
 218 static int __init root_data_setup(char *str)
 219 {
 220         root_mount_data = str;
 221         return 1;
 222 }
 223
 224 static char * __initdata root_fs_names;
 225 static int __init fs_names_setup(char *str)
 226 {
 227         root_fs_names = str;
 228         return 1;
 229 }
 230
 231 static unsigned int __initdata root_delay;
 232 static 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
 242 static 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
 269 static 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
 284 void __init mount_block_root(char *name, int flags)
 285 {
 286         char *fs_names = __getname();
 287         char *p;
 288 #ifdef CONFIG_BLOCK
 289         char b[BDEVNAME_SIZE];
 290 #else
 291         const char *b = name;
 292 #endif
 293
 294         get_fs_names(fs_names);
 295 retry:
 296         for (p = fs_names; *p; p += strlen(p)+1) {
 297                 int err = do_mount_root(name, p, flags, root_mount_data);
 298                 switch (err) {
 299                         case 0:
 300                                 goto out;
 301                         case -EACCES:
 302                                 flags |= MS_RDONLY;
 303                                 goto retry;
 304                         case -EINVAL:
 305                                 continue;
 306                 }
 307                 /*
 308                  * Allow the user to distinguish between failed sys_open
 309                  * and bad superblock on root device.
 310                  */
 311 #ifdef CONFIG_BLOCK
 312                 __bdevname(ROOT_DEV, b);
 313 #endif
 314                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 315                                 root_device_name, b);
 316                 printk("Please append a correct \"root=\" boot option\n");
 317
 318                 panic("VFS: Unable to mount root fs on %s", b);
 319         }
 320
 321         printk("No filesystem could mount root, tried: ");
 322         for (p = fs_names; *p; p += strlen(p)+1)
 323                 printk(" %s", p);
 324         printk("\n");
 325 #ifdef CONFIG_BLOCK
 326         __bdevname(ROOT_DEV, b);
 327 #endif
 328         panic("VFS: Unable to mount root fs on %s", b);
 329 out:
 330         putname(fs_names);
 331 }
 332
 333 #ifdef CONFIG_ROOT_NFS
 334 static int __init mount_nfs_root(void)
 335 {
 336         void *data = nfs_root_data();
 337
 338         create_dev("/dev/root", ROOT_DEV);
 339         if (data &&
 340             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 341                 return 1;
 342         return 0;
 343 }
 344 #endif
 345
 346 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 347 void __init change_floppy(char *fmt, ...)
 348 {
 349         struct termios termios;
 350         char buf[80];
 351         char c;
 352         int fd;
 353         va_list args;
 354         va_start(args, fmt);
 355         vsprintf(buf, fmt, args);
 356         va_end(args);
 357         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 358         if (fd >= 0) {
 359                 sys_ioctl(fd, FDEJECT, 0);
 360                 sys_close(fd);
 361         }
 362         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 363         fd = sys_open("/dev/console", O_RDWR, 0);
 364         if (fd >= 0) {
 365                 sys_ioctl(fd, TCGETS, (long)&termios);
 366                 termios.c_lflag &= ~ICANON;
 367                 sys_ioctl(fd, TCSETSF, (long)&termios);
 368                 sys_read(fd, &c, 1);
 369                 termios.c_lflag |= ICANON;
 370                 sys_ioctl(fd, TCSETSF, (long)&termios);
 371                 sys_close(fd);
 372         }
 373 }
 374 #endif
 375
 376 void __init mount_root(void)
 377 {
 378 #ifdef CONFIG_ROOT_NFS
 379         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 380                 if (mount_nfs_root())
 381                         return;
 382
 383                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 384                 ROOT_DEV = Root_FD0;
 385         }
 386 #endif
 387 #ifdef CONFIG_BLK_DEV_FD
 388         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 389                 /* rd_doload is 2 for a dual initrd/ramload setup */
 390                 if (rd_doload==2) {
 391                         if (rd_load_disk(1)) {
 392                                 ROOT_DEV = Root_RAM1;
 393                                 root_device_name = NULL;
 394                         }
 395                 } else
 396                         change_floppy("root floppy");
 397         }
 398 #endif
 399 #ifdef CONFIG_BLOCK
 400         create_dev("/dev/root", ROOT_DEV);
 401         mount_block_root("/dev/root", root_mountflags);
 402 #endif
 403 }
 404
 405 /*
 406  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 407  */
 408 void __init prepare_namespace(void)
 409 {
 410         int is_floppy;
 411
 412         if (root_delay) {
 413                 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
 414                        root_delay);
 415                 ssleep(root_delay);
 416         }
 417
 418         /* wait for the known devices to complete their probing */
 419         while (driver_probe_done() != 0)
 420                 msleep(100);
 421
 422         md_run_setup();
 423
 424         if (saved_root_name[0]) {
 425                 root_device_name = saved_root_name;
 426                 if (!strncmp(root_device_name, "mtd", 3)) {
 427                         mount_block_root(root_device_name, root_mountflags);
 428                         goto out;
 429                 }
 430                 ROOT_DEV = name_to_dev_t(root_device_name);
 431                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 432                         root_device_name += 5;
 433         }
 434
 435         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 436
 437         if (initrd_load())
 438                 goto out;
 439
 440         if (is_floppy && rd_doload && rd_load_disk(0))
 441                 ROOT_DEV = Root_RAM0;
 442
 443         mount_root();
 444 out:
 445         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 446         sys_chroot(".");
 447         security_sb_post_mountroot();
 448 }
 449