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