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