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
  11 #include <linux/nfs_fs.h>
  12 #include <linux/nfs_fs_sb.h>
  13 #include <linux/nfs_mount.h>
  14
  15 #include "do_mounts.h"
  16
  17 extern int get_filesystem_list(char * buf);
  18
  19 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  20
  21 int root_mountflags = MS_RDONLY | MS_VERBOSE;
  22 char * __initdata root_device_name;
  23 static char __initdata saved_root_name[64];
  24
  25 /* this is initialized in init/main.c */
  26 dev_t ROOT_DEV;
  27
  28 EXPORT_SYMBOL(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  *      Driverfs 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 driverfs node has them replaced with
 134  *      bangs.  try_name() does the actual checks, assuming that driverfs
 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         char b[BDEVNAME_SIZE];
 290
 291         get_fs_names(fs_names);
 292 retry:
 293         for (p = fs_names; *p; p += strlen(p)+1) {
 294                 int err = do_mount_root(name, p, flags, root_mount_data);
 295                 switch (err) {
 296                         case 0:
 297                                 goto out;
 298                         case -EACCES:
 299                                 flags |= MS_RDONLY;
 300                                 goto retry;
 301                         case -EINVAL:
 302                                 continue;
 303                 }
 304                 /*
 305                  * Allow the user to distinguish between failed sys_open
 306                  * and bad superblock on root device.
 307                  */
 308                 __bdevname(ROOT_DEV, b);
 309                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 310                                 root_device_name, b);
 311                 printk("Please append a correct \"root=\" boot option\n");
 312
 313                 panic("VFS: Unable to mount root fs on %s", b);
 314         }
 315         panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
 316 out:
 317         putname(fs_names);
 318 }
 319
 320 #ifdef CONFIG_ROOT_NFS
 321 static int __init mount_nfs_root(void)
 322 {
 323         void *data = nfs_root_data();
 324
 325         create_dev("/dev/root", ROOT_DEV, NULL);
 326         if (data &&
 327             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 328                 return 1;
 329         return 0;
 330 }
 331 #endif
 332
 333 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 334 void __init change_floppy(char *fmt, ...)
 335 {
 336         struct termios termios;
 337         char buf[80];
 338         char c;
 339         int fd;
 340         va_list args;
 341         va_start(args, fmt);
 342         vsprintf(buf, fmt, args);
 343         va_end(args);
 344         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 345         if (fd >= 0) {
 346                 sys_ioctl(fd, FDEJECT, 0);
 347                 sys_close(fd);
 348         }
 349         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 350         fd = sys_open("/dev/console", O_RDWR, 0);
 351         if (fd >= 0) {
 352                 sys_ioctl(fd, TCGETS, (long)&termios);
 353                 termios.c_lflag &= ~ICANON;
 354                 sys_ioctl(fd, TCSETSF, (long)&termios);
 355                 sys_read(fd, &c, 1);
 356                 termios.c_lflag |= ICANON;
 357                 sys_ioctl(fd, TCSETSF, (long)&termios);
 358                 sys_close(fd);
 359         }
 360 }
 361 #endif
 362
 363 void __init mount_root(void)
 364 {
 365 #ifdef CONFIG_ROOT_NFS
 366         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 367                 if (mount_nfs_root())
 368                         return;
 369
 370                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 371                 ROOT_DEV = Root_FD0;
 372         }
 373 #endif
 374 #ifdef CONFIG_BLK_DEV_FD
 375         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 376                 /* rd_doload is 2 for a dual initrd/ramload setup */
 377                 if (rd_doload==2) {
 378                         if (rd_load_disk(1)) {
 379                                 ROOT_DEV = Root_RAM1;
 380                                 root_device_name = NULL;
 381                         }
 382                 } else
 383                         change_floppy("root floppy");
 384         }
 385 #endif
 386         create_dev("/dev/root", ROOT_DEV, root_device_name);
 387         mount_block_root("/dev/root", root_mountflags);
 388 }
 389
 390 /*
 391  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 392  */
 393 void __init prepare_namespace(void)
 394 {
 395         int is_floppy;
 396
 397         mount_devfs();
 398
 399         if (root_delay) {
 400                 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
 401                        root_delay);
 402                 ssleep(root_delay);
 403         }
 404
 405         md_run_setup();
 406
 407         if (saved_root_name[0]) {
 408                 root_device_name = saved_root_name;
 409                 ROOT_DEV = name_to_dev_t(root_device_name);
 410                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 411                         root_device_name += 5;
 412         }
 413
 414         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 415
 416         if (initrd_load())
 417                 goto out;
 418
 419         if (is_floppy && rd_doload && rd_load_disk(0))
 420                 ROOT_DEV = Root_RAM0;
 421
 422         mount_root();
 423 out:
 424         umount_devfs("/dev");
 425         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 426         sys_chroot(".");
 427         security_sb_post_mountroot();
 428         mount_devfs_fs ();
 429 }
 430