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/genhd.h>
  11 #include <linux/mount.h>
  12 #include <linux/device.h>
  13 #include <linux/init.h>
  14
  15 #include <linux/nfs_fs.h>
  16 #include <linux/nfs_fs_sb.h>
  17 #include <linux/nfs_mount.h>
  18
  19 #include "do_mounts.h"
  20
  21 extern int get_filesystem_list(char * buf);
  22
  23 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  24
  25 int root_mountflags = MS_RDONLY | MS_SILENT;
  26 char * __initdata root_device_name;
  27 static char __initdata saved_root_name[64];
  28
  29 dev_t 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  *      Sysfs 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 sysfs node has them replaced with
 135  *      bangs.  try_name() does the actual checks, assuming that sysfs
 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, mount_result;
 145
 146 #ifdef CONFIG_SYSFS
 147         int mkdir_err = sys_mkdir("/sys", 0700);
 148         /*
 149          * When changing resume parameter for suspend2, sysfs may
 150          * already be mounted.
 151          */
 152         mount_result = sys_mount("sysfs", "/sys", "sysfs", 0, NULL);
 153         if (mount_result < 0 && mount_result != -EBUSY)
 154                 goto out;
 155 #endif
 156
 157         if (strncmp(name, "/dev/", 5) != 0) {
 158                 unsigned maj, min;
 159
 160                 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
 161                         res = MKDEV(maj, min);
 162                         if (maj != MAJOR(res) || min != MINOR(res))
 163                                 goto fail;
 164                 } else {
 165                         res = new_decode_dev(simple_strtoul(name, &p, 16));
 166                         if (*p)
 167                                 goto fail;
 168                 }
 169                 goto done;
 170         }
 171         name += 5;
 172         res = Root_NFS;
 173         if (strcmp(name, "nfs") == 0)
 174                 goto done;
 175         res = Root_RAM0;
 176         if (strcmp(name, "ram") == 0)
 177                 goto done;
 178
 179         if (strlen(name) > 31)
 180                 goto fail;
 181         strcpy(s, name);
 182         for (p = s; *p; p++)
 183                 if (*p == '/')
 184                         *p = '!';
 185         res = try_name(s, 0);
 186         if (res)
 187                 goto done;
 188
 189         while (p > s && isdigit(p[-1]))
 190                 p--;
 191         if (p == s || !*p || *p == '0')
 192                 goto fail;
 193         part = simple_strtoul(p, NULL, 10);
 194         *p = '\0';
 195         res = try_name(s, part);
 196         if (res)
 197                 goto done;
 198
 199         if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
 200                 goto fail;
 201         p[-1] = '\0';
 202         res = try_name(s, part);
 203 done:
 204 #ifdef CONFIG_SYSFS
 205         if (mount_result >= 0)
 206                 sys_umount("/sys", 0);
 207 out:
 208         if (!mkdir_err)
 209                 sys_rmdir("/sys");
 210 #endif
 211         return res;
 212 fail:
 213         res = 0;
 214         goto done;
 215 }
 216
 217 static int __init root_dev_setup(char *line)
 218 {
 219         strlcpy(saved_root_name, line, sizeof(saved_root_name));
 220         return 1;
 221 }
 222
 223 __setup("root=", root_dev_setup);
 224
 225 static char * __initdata root_mount_data;
 226 static int __init root_data_setup(char *str)
 227 {
 228         root_mount_data = str;
 229         return 1;
 230 }
 231
 232 static char * __initdata root_fs_names;
 233 static int __init fs_names_setup(char *str)
 234 {
 235         root_fs_names = str;
 236         return 1;
 237 }
 238
 239 static unsigned int __initdata root_delay;
 240 static int __init root_delay_setup(char *str)
 241 {
 242         root_delay = simple_strtoul(str, NULL, 0);
 243         return 1;
 244 }
 245
 246 __setup("rootflags=", root_data_setup);
 247 __setup("rootfstype=", fs_names_setup);
 248 __setup("rootdelay=", root_delay_setup);
 249
 250 static void __init get_fs_names(char *page)
 251 {
 252         char *s = page;
 253
 254         if (root_fs_names) {
 255                 strcpy(page, root_fs_names);
 256                 while (*s++) {
 257                         if (s[-1] == ',')
 258                                 s[-1] = '\0';
 259                 }
 260         } else {
 261                 int len = get_filesystem_list(page);
 262                 char *p, *next;
 263
 264                 page[len] = '\0';
 265                 for (p = page-1; p; p = next) {
 266                         next = strchr(++p, '\n');
 267                         if (*p++ != '\t')
 268                                 continue;
 269                         while ((*s++ = *p++) != '\n')
 270                                 ;
 271                         s[-1] = '\0';
 272                 }
 273         }
 274         *s = '\0';
 275 }
 276
 277 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 278 {
 279         int err = sys_mount(name, "/root", fs, flags, data);
 280         if (err)
 281                 return err;
 282
 283         sys_chdir("/root");
 284         ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
 285         printk("VFS: Mounted root (%s filesystem)%s.\n",
 286                current->fs->pwdmnt->mnt_sb->s_type->name,
 287                current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
 288                " readonly" : "");
 289         return 0;
 290 }
 291
 292 void __init mount_block_root(char *name, int flags)
 293 {
 294         char *fs_names = __getname();
 295         char *p;
 296 #ifdef CONFIG_BLOCK
 297         char b[BDEVNAME_SIZE];
 298 #else
 299         const char *b = name;
 300 #endif
 301
 302         get_fs_names(fs_names);
 303 retry:
 304         for (p = fs_names; *p; p += strlen(p)+1) {
 305                 int err = do_mount_root(name, p, flags, root_mount_data);
 306                 switch (err) {
 307                         case 0:
 308                                 goto out;
 309                         case -EACCES:
 310                                 flags |= MS_RDONLY;
 311                                 goto retry;
 312                         case -EINVAL:
 313                                 continue;
 314                 }
 315                 /*
 316                  * Allow the user to distinguish between failed sys_open
 317                  * and bad superblock on root device.
 318                  * and give them a list of the available devices
 319                  */
 320 #ifdef CONFIG_BLOCK
 321                 __bdevname(ROOT_DEV, b);
 322 #endif
 323                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 324                                 root_device_name, b);
 325                 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
 326
 327                 printk_all_partitions();
 328                 panic("VFS: Unable to mount root fs on %s", b);
 329         }
 330
 331         printk("List of all partitions:\n");
 332         printk_all_partitions();
 333         printk("No filesystem could mount root, tried: ");
 334         for (p = fs_names; *p; p += strlen(p)+1)
 335                 printk(" %s", p);
 336         printk("\n");
 337 #ifdef CONFIG_BLOCK
 338         __bdevname(ROOT_DEV, b);
 339 #endif
 340         panic("VFS: Unable to mount root fs on %s", b);
 341 out:
 342         putname(fs_names);
 343 }
 344
 345 #ifdef CONFIG_ROOT_NFS
 346 static int __init mount_nfs_root(void)
 347 {
 348         void *data = nfs_root_data();
 349
 350         create_dev("/dev/root", ROOT_DEV);
 351         if (data &&
 352             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 353                 return 1;
 354         return 0;
 355 }
 356 #endif
 357
 358 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 359 void __init change_floppy(char *fmt, ...)
 360 {
 361         struct termios termios;
 362         char buf[80];
 363         char c;
 364         int fd;
 365         va_list args;
 366         va_start(args, fmt);
 367         vsprintf(buf, fmt, args);
 368         va_end(args);
 369         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 370         if (fd >= 0) {
 371                 sys_ioctl(fd, FDEJECT, 0);
 372                 sys_close(fd);
 373         }
 374         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 375         fd = sys_open("/dev/console", O_RDWR, 0);
 376         if (fd >= 0) {
 377                 sys_ioctl(fd, TCGETS, (long)&termios);
 378                 termios.c_lflag &= ~ICANON;
 379                 sys_ioctl(fd, TCSETSF, (long)&termios);
 380                 sys_read(fd, &c, 1);
 381                 termios.c_lflag |= ICANON;
 382                 sys_ioctl(fd, TCSETSF, (long)&termios);
 383                 sys_close(fd);
 384         }
 385 }
 386 #endif
 387
 388 void __init mount_root(void)
 389 {
 390 #ifdef CONFIG_ROOT_NFS
 391         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 392                 if (mount_nfs_root())
 393                         return;
 394
 395                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 396                 ROOT_DEV = Root_FD0;
 397         }
 398 #endif
 399 #ifdef CONFIG_BLK_DEV_FD
 400         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 401                 /* rd_doload is 2 for a dual initrd/ramload setup */
 402                 if (rd_doload==2) {
 403                         if (rd_load_disk(1)) {
 404                                 ROOT_DEV = Root_RAM1;
 405                                 root_device_name = NULL;
 406                         }
 407                 } else
 408                         change_floppy("root floppy");
 409         }
 410 #endif
 411 #ifdef CONFIG_BLOCK
 412         create_dev("/dev/root", ROOT_DEV);
 413         mount_block_root("/dev/root", root_mountflags);
 414 #endif
 415 }
 416
 417 /*
 418  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 419  */
 420 void __init prepare_namespace(void)
 421 {
 422         int is_floppy;
 423
 424         if (root_delay) {
 425                 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
 426                        root_delay);
 427                 ssleep(root_delay);
 428         }
 429
 430         /* wait for the known devices to complete their probing */
 431         while (driver_probe_done() != 0)
 432                 msleep(100);
 433
 434         md_run_setup();
 435
 436         if (saved_root_name[0]) {
 437                 root_device_name = saved_root_name;
 438                 if (!strncmp(root_device_name, "mtd", 3)) {
 439                         mount_block_root(root_device_name, root_mountflags);
 440                         goto out;
 441                 }
 442                 ROOT_DEV = name_to_dev_t(root_device_name);
 443                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 444                         root_device_name += 5;
 445         }
 446
 447         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 448
 449         /* Suspend2:
 450          * By this point, suspend_early_init has been called to initialise our
 451          * sysfs interface. If modules are built in, they have registered (all
 452          * of the above via initcalls).
 453          *
 454          * We have not yet looked to see if an image exists, however. If we
 455          * have an initrd, it is expected that the user will have set it up
 456          * to echo > /sys/power/suspend2/do_resume and thus initiate any
 457          * resume. If they don't do that, we do it immediately after the initrd
 458          * is finished (major issues if they mount filesystems rw from the
 459          * initrd! - they are warned. If there's no usable initrd, we do our
 460          * check next.
 461          */
 462         if (initrd_load())
 463                 goto out;
 464
 465         if (is_floppy && rd_doload && rd_load_disk(0))
 466                 ROOT_DEV = Root_RAM0;
 467
 468         check_resume_attempted();
 469
 470         mount_root();
 471 out:
 472         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 473         sys_chroot(".");
 474         security_sb_post_mountroot();
 475 }
 476