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
  10 #include <linux/nfs_fs.h>
  11 #include <linux/nfs_fs_sb.h>
  12 #include <linux/nfs_mount.h>
  13
  14 #include "do_mounts.h"
  15
  16 extern int get_filesystem_list(char * buf);
  17
  18 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  19
  20 int root_mountflags = MS_RDONLY | MS_VERBOSE;
  21 char * __initdata root_device_name;
  22 static char __initdata saved_root_name[64];
  23
  24 /* this is initialized in init/main.c */
  25 dev_t ROOT_DEV;
  26
  27 EXPORT_SYMBOL(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 __init 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  *      Driverfs 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 driverfs node has them replaced with
 133  *      bangs.  try_name() does the actual checks, assuming that driverfs
 134  *      is mounted on rootfs /sys.
 135  */
 136
 137 dev_t __init name_to_dev_t(char *name)
 138 {
 139         char s[32];
 140         char *p;
 141         dev_t res = 0;
 142         int part;
 143
 144         sys_mkdir("/sys", 0700);
 145         if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
 146                 goto out;
 147
 148         if (strncmp(name, "/dev/", 5) != 0) {
 149                 unsigned maj, min;
 150
 151                 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
 152                         res = MKDEV(maj, min);
 153                         if (maj != MAJOR(res) || min != MINOR(res))
 154                                 goto fail;
 155                 } else {
 156                         res = new_decode_dev(simple_strtoul(name, &p, 16));
 157                         if (*p)
 158                                 goto fail;
 159                 }
 160                 goto done;
 161         }
 162         name += 5;
 163         res = Root_NFS;
 164         if (strcmp(name, "nfs") == 0)
 165                 goto done;
 166         res = Root_RAM0;
 167         if (strcmp(name, "ram") == 0)
 168                 goto done;
 169
 170         if (strlen(name) > 31)
 171                 goto fail;
 172         strcpy(s, name);
 173         for (p = s; *p; p++)
 174                 if (*p == '/')
 175                         *p = '!';
 176         res = try_name(s, 0);
 177         if (res)
 178                 goto done;
 179
 180         while (p > s && isdigit(p[-1]))
 181                 p--;
 182         if (p == s || !*p || *p == '0')
 183                 goto fail;
 184         part = simple_strtoul(p, NULL, 10);
 185         *p = '\0';
 186         res = try_name(s, part);
 187         if (res)
 188                 goto done;
 189
 190         if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
 191                 goto fail;
 192         p[-1] = '\0';
 193         res = try_name(s, part);
 194 done:
 195         sys_umount("/sys", 0);
 196 out:
 197         sys_rmdir("/sys");
 198         return res;
 199 fail:
 200         res = 0;
 201         goto done;
 202 }
 203
 204 static int __init root_dev_setup(char *line)
 205 {
 206         strlcpy(saved_root_name, line, sizeof(saved_root_name));
 207         return 1;
 208 }
 209
 210 __setup("root=", root_dev_setup);
 211
 212 static char * __initdata root_mount_data;
 213 static int __init root_data_setup(char *str)
 214 {
 215         root_mount_data = str;
 216         return 1;
 217 }
 218
 219 static char * __initdata root_fs_names;
 220 static int __init fs_names_setup(char *str)
 221 {
 222         root_fs_names = str;
 223         return 1;
 224 }
 225
 226 __setup("rootflags=", root_data_setup);
 227 __setup("rootfstype=", fs_names_setup);
 228
 229 static void __init get_fs_names(char *page)
 230 {
 231         char *s = page;
 232
 233         if (root_fs_names) {
 234                 strcpy(page, root_fs_names);
 235                 while (*s++) {
 236                         if (s[-1] == ',')
 237                                 s[-1] = '\0';
 238                 }
 239         } else {
 240                 int len = get_filesystem_list(page);
 241                 char *p, *next;
 242
 243                 page[len] = '\0';
 244                 for (p = page-1; p; p = next) {
 245                         next = strchr(++p, '\n');
 246                         if (*p++ != '\t')
 247                                 continue;
 248                         while ((*s++ = *p++) != '\n')
 249                                 ;
 250                         s[-1] = '\0';
 251                 }
 252         }
 253         *s = '\0';
 254 }
 255
 256 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 257 {
 258         int err = sys_mount(name, "/root", fs, flags, data);
 259         if (err)
 260                 return err;
 261
 262         sys_chdir("/root");
 263         ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
 264         printk("VFS: Mounted root (%s filesystem)%s.\n",
 265                current->fs->pwdmnt->mnt_sb->s_type->name,
 266                current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
 267                " readonly" : "");
 268         return 0;
 269 }
 270
 271 void __init mount_block_root(char *name, int flags)
 272 {
 273         char *fs_names = __getname();
 274         char *p;
 275         char b[BDEVNAME_SIZE];
 276
 277         get_fs_names(fs_names);
 278 retry:
 279         for (p = fs_names; *p; p += strlen(p)+1) {
 280                 int err = do_mount_root(name, p, flags, root_mount_data);
 281                 switch (err) {
 282                         case 0:
 283                                 goto out;
 284                         case -EACCES:
 285                                 flags |= MS_RDONLY;
 286                                 goto retry;
 287                         case -EINVAL:
 288                                 continue;
 289                 }
 290                 /*
 291                  * Allow the user to distinguish between failed sys_open
 292                  * and bad superblock on root device.
 293                  */
 294                 __bdevname(ROOT_DEV, b);
 295                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 296                                 root_device_name, b);
 297                 printk("Please append a correct \"root=\" boot option\n");
 298
 299                 panic("VFS: Unable to mount root fs on %s", b);
 300         }
 301         panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
 302 out:
 303         putname(fs_names);
 304 }
 305
 306 #ifdef CONFIG_ROOT_NFS
 307 static int __init mount_nfs_root(void)
 308 {
 309         void *data = nfs_root_data();
 310
 311         create_dev("/dev/root", ROOT_DEV, NULL);
 312         if (data &&
 313             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 314                 return 1;
 315         return 0;
 316 }
 317 #endif
 318
 319 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 320 void __init change_floppy(char *fmt, ...)
 321 {
 322         struct termios termios;
 323         char buf[80];
 324         char c;
 325         int fd;
 326         va_list args;
 327         va_start(args, fmt);
 328         vsprintf(buf, fmt, args);
 329         va_end(args);
 330         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 331         if (fd >= 0) {
 332                 sys_ioctl(fd, FDEJECT, 0);
 333                 sys_close(fd);
 334         }
 335         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 336         fd = sys_open("/dev/console", O_RDWR, 0);
 337         if (fd >= 0) {
 338                 sys_ioctl(fd, TCGETS, (long)&termios);
 339                 termios.c_lflag &= ~ICANON;
 340                 sys_ioctl(fd, TCSETSF, (long)&termios);
 341                 sys_read(fd, &c, 1);
 342                 termios.c_lflag |= ICANON;
 343                 sys_ioctl(fd, TCSETSF, (long)&termios);
 344                 sys_close(fd);
 345         }
 346 }
 347 #endif
 348
 349 void __init mount_root(void)
 350 {
 351 #ifdef CONFIG_ROOT_NFS
 352         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 353                 if (mount_nfs_root())
 354                         return;
 355
 356                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 357                 ROOT_DEV = Root_FD0;
 358         }
 359 #endif
 360 #ifdef CONFIG_BLK_DEV_FD
 361         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 362                 /* rd_doload is 2 for a dual initrd/ramload setup */
 363                 if (rd_doload==2) {
 364                         if (rd_load_disk(1)) {
 365                                 ROOT_DEV = Root_RAM1;
 366                                 root_device_name = NULL;
 367                         }
 368                 } else
 369                         change_floppy("root floppy");
 370         }
 371 #endif
 372         create_dev("/dev/root", ROOT_DEV, root_device_name);
 373         mount_block_root("/dev/root", root_mountflags);
 374 }
 375
 376 /*
 377  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 378  */
 379 void __init prepare_namespace(void)
 380 {
 381         int is_floppy;
 382
 383         mount_devfs();
 384
 385         md_run_setup();
 386
 387         if (saved_root_name[0]) {
 388                 root_device_name = saved_root_name;
 389                 ROOT_DEV = name_to_dev_t(root_device_name);
 390                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 391                         root_device_name += 5;
 392         }
 393
 394         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 395
 396         if (initrd_load())
 397                 goto out;
 398
 399         if (is_floppy && rd_doload && rd_load_disk(0))
 400                 ROOT_DEV = Root_RAM0;
 401
 402         mount_root();
 403 out:
 404         umount_devfs("/dev");
 405         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 406         sys_chroot(".");
 407         security_sb_post_mountroot();
 408         mount_devfs_fs ();
 409 }
 410