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 #include <linux/init.h>
  13
  14 #include <linux/nfs_fs.h>
  15 #include <linux/nfs_fs_sb.h>
  16 #include <linux/nfs_mount.h>
  17
  18 #include "do_mounts.h"
  19
  20 extern int get_filesystem_list(char * buf);
  21
  22 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  23
  24 int root_mountflags = MS_RDONLY | MS_SILENT;
  25 char * __initdata root_device_name;
  26 static char __initdata saved_root_name[64];
  27
  28 dev_t ROOT_DEV;
  29
  30 static int __init load_ramdisk(char *str)
  31 {
  32         rd_doload = simple_strtol(str,NULL,0) & 3;
  33         return 1;
  34 }
  35 __setup("load_ramdisk=", load_ramdisk);
  36
  37 static int __init readonly(char *str)
  38 {
  39         if (*str)
  40                 return 0;
  41         root_mountflags |= MS_RDONLY;
  42         return 1;
  43 }
  44
  45 static int __init readwrite(char *str)
  46 {
  47         if (*str)
  48                 return 0;
  49         root_mountflags &= ~MS_RDONLY;
  50         return 1;
  51 }
  52
  53 __setup("ro", readonly);
  54 __setup("rw", readwrite);
  55
  56 static dev_t try_name(char *name, int part)
  57 {
  58         char path[64];
  59         char buf[32];
  60         int range;
  61         dev_t res;
  62         char *s;
  63         int len;
  64         int fd;
  65         unsigned int maj, min;
  66
  67         /* read device number from .../dev */
  68
  69         sprintf(path, "/sys/block/%s/dev", name);
  70         fd = sys_open(path, 0, 0);
  71         if (fd < 0)
  72                 goto fail;
  73         len = sys_read(fd, buf, 32);
  74         sys_close(fd);
  75         if (len <= 0 || len == 32 || buf[len - 1] != '\n')
  76                 goto fail;
  77         buf[len - 1] = '\0';
  78         if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
  79                 /*
  80                  * Try the %u:%u format -- see print_dev_t()
  81                  */
  82                 res = MKDEV(maj, min);
  83                 if (maj != MAJOR(res) || min != MINOR(res))
  84                         goto fail;
  85         } else {
  86                 /*
  87                  * Nope.  Try old-style "0321"
  88                  */
  89                 res = new_decode_dev(simple_strtoul(buf, &s, 16));
  90                 if (*s)
  91                         goto fail;
  92         }
  93
  94         /* if it's there and we are not looking for a partition - that's it */
  95         if (!part)
  96                 return res;
  97
  98         /* otherwise read range from .../range */
  99         sprintf(path, "/sys/block/%s/range", name);
 100         fd = sys_open(path, 0, 0);
 101         if (fd < 0)
 102                 goto fail;
 103         len = sys_read(fd, buf, 32);
 104         sys_close(fd);
 105         if (len <= 0 || len == 32 || buf[len - 1] != '\n')
 106                 goto fail;
 107         buf[len - 1] = '\0';
 108         range = simple_strtoul(buf, &s, 10);
 109         if (*s)
 110                 goto fail;
 111
 112         /* if partition is within range - we got it */
 113         if (part < range)
 114                 return res + part;
 115 fail:
 116         return 0;
 117 }
 118
 119 /*
 120  *      Convert a name into device number.  We accept the following variants:
 121  *
 122  *      1) device number in hexadecimal represents itself
 123  *      2) /dev/nfs represents Root_NFS (0xff)
 124  *      3) /dev/<disk_name> represents the device number of disk
 125  *      4) /dev/<disk_name><decimal> represents the device number
 126  *         of partition - device number of disk plus the partition number
 127  *      5) /dev/<disk_name>p<decimal> - same as the above, that form is
 128  *         used when disk name of partitioned disk ends on a digit.
 129  *
 130  *      If name doesn't have fall into the categories above, we return 0.
 131  *      Sysfs is used to check if something is a disk name - it has
 132  *      all known disks under bus/block/devices.  If the disk name
 133  *      contains slashes, name of sysfs node has them replaced with
 134  *      bangs.  try_name() does the actual checks, assuming that sysfs
 135  *      is mounted on rootfs /sys.
 136  */
 137
 138 dev_t name_to_dev_t(char *name)
 139 {
 140         char s[32];
 141         char *p;
 142         dev_t res = 0;
 143         int part;
 144
 145 #ifdef CONFIG_SYSFS
 146         int mkdir_err = sys_mkdir("/sys", 0700);
 147         if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
 148                 goto out;
 149 #endif
 150
 151         if (strncmp(name, "/dev/", 5) != 0) {
 152                 unsigned maj, min;
 153
 154                 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
 155                         res = MKDEV(maj, min);
 156                         if (maj != MAJOR(res) || min != MINOR(res))
 157                                 goto fail;
 158                 } else {
 159                         res = new_decode_dev(simple_strtoul(name, &p, 16));
 160                         if (*p)
 161                                 goto fail;
 162                 }
 163                 goto done;
 164         }
 165         name += 5;
 166         res = Root_NFS;
 167         if (strcmp(name, "nfs") == 0)
 168                 goto done;
 169         res = Root_RAM0;
 170         if (strcmp(name, "ram") == 0)
 171                 goto done;
 172
 173         if (strlen(name) > 31)
 174                 goto fail;
 175         strcpy(s, name);
 176         for (p = s; *p; p++)
 177                 if (*p == '/')
 178                         *p = '!';
 179         res = try_name(s, 0);
 180         if (res)
 181                 goto done;
 182
 183         while (p > s && isdigit(p[-1]))
 184                 p--;
 185         if (p == s || !*p || *p == '0')
 186                 goto fail;
 187         part = simple_strtoul(p, NULL, 10);
 188         *p = '\0';
 189         res = try_name(s, part);
 190         if (res)
 191                 goto done;
 192
 193         if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
 194                 goto fail;
 195         p[-1] = '\0';
 196         res = try_name(s, part);
 197 done:
 198 #ifdef CONFIG_SYSFS
 199         sys_umount("/sys", 0);
 200 out:
 201         if (!mkdir_err)
 202                 sys_rmdir("/sys");
 203 #endif
 204         return res;
 205 fail:
 206         res = 0;
 207         goto done;
 208 }
 209
 210 static int __init root_dev_setup(char *line)
 211 {
 212         strlcpy(saved_root_name, line, sizeof(saved_root_name));
 213         return 1;
 214 }
 215
 216 __setup("root=", root_dev_setup);
 217
 218 static char * __initdata root_mount_data;
 219 static int __init root_data_setup(char *str)
 220 {
 221         root_mount_data = str;
 222         return 1;
 223 }
 224
 225 static char * __initdata root_fs_names;
 226 static int __init fs_names_setup(char *str)
 227 {
 228         root_fs_names = str;
 229         return 1;
 230 }
 231
 232 static unsigned int __initdata root_delay;
 233 static int __init root_delay_setup(char *str)
 234 {
 235         root_delay = simple_strtoul(str, NULL, 0);
 236         return 1;
 237 }
 238
 239 __setup("rootflags=", root_data_setup);
 240 __setup("rootfstype=", fs_names_setup);
 241 __setup("rootdelay=", root_delay_setup);
 242
 243 static void __init get_fs_names(char *page)
 244 {
 245         char *s = page;
 246
 247         if (root_fs_names) {
 248                 strcpy(page, root_fs_names);
 249                 while (*s++) {
 250                         if (s[-1] == ',')
 251                                 s[-1] = '\0';
 252                 }
 253         } else {
 254                 int len = get_filesystem_list(page);
 255                 char *p, *next;
 256
 257                 page[len] = '\0';
 258                 for (p = page-1; p; p = next) {
 259                         next = strchr(++p, '\n');
 260                         if (*p++ != '\t')
 261                                 continue;
 262                         while ((*s++ = *p++) != '\n')
 263                                 ;
 264                         s[-1] = '\0';
 265                 }
 266         }
 267         *s = '\0';
 268 }
 269
 270 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 271 {
 272         int err = sys_mount(name, "/root", fs, flags, data);
 273         if (err)
 274                 return err;
 275
 276         sys_chdir("/root");
 277         ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
 278         printk("VFS: Mounted root (%s filesystem)%s.\n",
 279                current->fs->pwdmnt->mnt_sb->s_type->name,
 280                current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
 281                " readonly" : "");
 282         return 0;
 283 }
 284
 285 void __init mount_block_root(char *name, int flags)
 286 {
 287         char *fs_names = __getname();
 288         char *p;
 289 #ifdef CONFIG_BLOCK
 290         char b[BDEVNAME_SIZE];
 291 #else
 292         const char *b = name;
 293 #endif
 294
 295         get_fs_names(fs_names);
 296 retry:
 297         for (p = fs_names; *p; p += strlen(p)+1) {
 298                 int err = do_mount_root(name, p, flags, root_mount_data);
 299                 switch (err) {
 300                         case 0:
 301                                 goto out;
 302                         case -EACCES:
 303                                 flags |= MS_RDONLY;
 304                                 goto retry;
 305                         case -EINVAL:
 306                                 continue;
 307                 }
 308                 /*
 309                  * Allow the user to distinguish between failed sys_open
 310                  * and bad superblock on root device.
 311                  */
 312 #ifdef CONFIG_BLOCK
 313                 __bdevname(ROOT_DEV, b);
 314 #endif
 315                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 316                                 root_device_name, b);
 317                 printk("Please append a correct \"root=\" boot option\n");
 318
 319                 panic("VFS: Unable to mount root fs on %s", b);
 320         }
 321
 322         printk("No filesystem could mount root, tried: ");
 323         for (p = fs_names; *p; p += strlen(p)+1)
 324                 printk(" %s", p);
 325         printk("\n");
 326 #ifdef CONFIG_BLOCK
 327         __bdevname(ROOT_DEV, b);
 328 #endif
 329         panic("VFS: Unable to mount root fs on %s", b);
 330 out:
 331         putname(fs_names);
 332 }
 333
 334 #ifdef CONFIG_ROOT_NFS
 335 static int __init mount_nfs_root(void)
 336 {
 337         void *data = nfs_root_data();
 338
 339         create_dev("/dev/root", ROOT_DEV);
 340         if (data &&
 341             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 342                 return 1;
 343         return 0;
 344 }
 345 #endif
 346
 347 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 348 void __init change_floppy(char *fmt, ...)
 349 {
 350         struct termios termios;
 351         char buf[80];
 352         char c;
 353         int fd;
 354         va_list args;
 355         va_start(args, fmt);
 356         vsprintf(buf, fmt, args);
 357         va_end(args);
 358         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 359         if (fd >= 0) {
 360                 sys_ioctl(fd, FDEJECT, 0);
 361                 sys_close(fd);
 362         }
 363         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 364         fd = sys_open("/dev/console", O_RDWR, 0);
 365         if (fd >= 0) {
 366                 sys_ioctl(fd, TCGETS, (long)&termios);
 367                 termios.c_lflag &= ~ICANON;
 368                 sys_ioctl(fd, TCSETSF, (long)&termios);
 369                 sys_read(fd, &c, 1);
 370                 termios.c_lflag |= ICANON;
 371                 sys_ioctl(fd, TCSETSF, (long)&termios);
 372                 sys_close(fd);
 373         }
 374 }
 375 #endif
 376
 377 void __init mount_root(void)
 378 {
 379 #ifdef CONFIG_ROOT_NFS
 380         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 381                 if (mount_nfs_root())
 382                         return;
 383
 384                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 385                 ROOT_DEV = Root_FD0;
 386         }
 387 #endif
 388 #ifdef CONFIG_BLK_DEV_FD
 389         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 390                 /* rd_doload is 2 for a dual initrd/ramload setup */
 391                 if (rd_doload==2) {
 392                         if (rd_load_disk(1)) {
 393                                 ROOT_DEV = Root_RAM1;
 394                                 root_device_name = NULL;
 395                         }
 396                 } else
 397                         change_floppy("root floppy");
 398         }
 399 #endif
 400 #ifdef CONFIG_BLOCK
 401         create_dev("/dev/root", ROOT_DEV);
 402         mount_block_root("/dev/root", root_mountflags);
 403 #endif
 404 }
 405
 406 /*
 407  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 408  */
 409 void __init prepare_namespace(void)
 410 {
 411         int is_floppy;
 412
 413         if (root_delay) {
 414                 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
 415                        root_delay);
 416                 ssleep(root_delay);
 417         }
 418
 419         /* wait for the known devices to complete their probing */
 420         while (driver_probe_done() != 0)
 421                 msleep(100);
 422
 423         md_run_setup();
 424
 425         if (saved_root_name[0]) {
 426                 root_device_name = saved_root_name;
 427                 if (!strncmp(root_device_name, "mtd", 3)) {
 428                         mount_block_root(root_device_name, root_mountflags);
 429                         goto out;
 430                 }
 431                 ROOT_DEV = name_to_dev_t(root_device_name);
 432                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 433                         root_device_name += 5;
 434         }
 435
 436         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 437
 438         if (initrd_load())
 439                 goto out;
 440
 441         if (is_floppy && rd_doload && rd_load_disk(0))
 442                 ROOT_DEV = Root_RAM0;
 443
 444         mount_root();
 445 out:
 446         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 447         sys_chroot(".");
 448         security_sb_post_mountroot();
 449 }
 450