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 #include <linux/fs_struct.h>
  18 #include <linux/slab.h>
  19
  20 #include <linux/nfs_fs.h>
  21 #include <linux/nfs_fs_sb.h>
  22 #include <linux/nfs_mount.h>
  23
  24 #include "do_mounts.h"
  25
  26 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  27
  28 int root_mountflags = MS_RDONLY | MS_SILENT;
  29 static char * __initdata root_device_name;
  30 static char __initdata saved_root_name[64];
  31 static int __initdata root_wait;
  32
  33 dev_t ROOT_DEV;
  34
  35 static int __init load_ramdisk(char *str)
  36 {
  37         rd_doload = simple_strtol(str,NULL,0) & 3;
  38         return 1;
  39 }
  40 __setup("load_ramdisk=", load_ramdisk);
  41
  42 static int __init readonly(char *str)
  43 {
  44         if (*str)
  45                 return 0;
  46         root_mountflags |= MS_RDONLY;
  47         return 1;
  48 }
  49
  50 static int __init readwrite(char *str)
  51 {
  52         if (*str)
  53                 return 0;
  54         root_mountflags &= ~MS_RDONLY;
  55         return 1;
  56 }
  57
  58 __setup("ro", readonly);
  59 __setup("rw", readwrite);
  60
  61 /*
  62  *      Convert a name into device number.  We accept the following variants:
  63  *
  64  *      1) device number in hexadecimal represents itself
  65  *      2) /dev/nfs represents Root_NFS (0xff)
  66  *      3) /dev/<disk_name> represents the device number of disk
  67  *      4) /dev/<disk_name><decimal> represents the device number
  68  *         of partition - device number of disk plus the partition number
  69  *      5) /dev/<disk_name>p<decimal> - same as the above, that form is
  70  *         used when disk name of partitioned disk ends on a digit.
  71  *
  72  *      If name doesn't have fall into the categories above, we return (0,0).
  73  *      block_class is used to check if something is a disk name. If the disk
  74  *      name contains slashes, the device name has them replaced with
  75  *      bangs.
  76  */
  77
  78 dev_t name_to_dev_t(char *name)
  79 {
  80         char s[32];
  81         char *p;
  82         dev_t res = 0;
  83         int part;
  84
  85         if (strncmp(name, "/dev/", 5) != 0) {
  86                 unsigned maj, min;
  87
  88                 if (sscanf(name, "%u:%u", &maj, &min) == 2) {
  89                         res = MKDEV(maj, min);
  90                         if (maj != MAJOR(res) || min != MINOR(res))
  91                                 goto fail;
  92                 } else {
  93                         res = new_decode_dev(simple_strtoul(name, &p, 16));
  94                         if (*p)
  95                                 goto fail;
  96                 }
  97                 goto done;
  98         }
  99
 100         name += 5;
 101         res = Root_NFS;
 102         if (strcmp(name, "nfs") == 0)
 103                 goto done;
 104         res = Root_RAM0;
 105         if (strcmp(name, "ram") == 0)
 106                 goto done;
 107
 108         if (strlen(name) > 31)
 109                 goto fail;
 110         strcpy(s, name);
 111         for (p = s; *p; p++)
 112                 if (*p == '/')
 113                         *p = '!';
 114         res = blk_lookup_devt(s, 0);
 115         if (res)
 116                 goto done;
 117
 118         /*
 119          * try non-existant, but valid partition, which may only exist
 120          * after revalidating the disk, like partitioned md devices
 121          */
 122         while (p > s && isdigit(p[-1]))
 123                 p--;
 124         if (p == s || !*p || *p == '0')
 125                 goto fail;
 126
 127         /* try disk name without <part number> */
 128         part = simple_strtoul(p, NULL, 10);
 129         *p = '\0';
 130         res = blk_lookup_devt(s, part);
 131         if (res)
 132                 goto done;
 133
 134         /* try disk name without p<part number> */
 135         if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
 136                 goto fail;
 137         p[-1] = '\0';
 138         res = blk_lookup_devt(s, part);
 139         if (res)
 140                 goto done;
 141
 142 fail:
 143         return 0;
 144 done:
 145         return res;
 146 }
 147
 148 static int __init root_dev_setup(char *line)
 149 {
 150         strlcpy(saved_root_name, line, sizeof(saved_root_name));
 151         return 1;
 152 }
 153
 154 __setup("root=", root_dev_setup);
 155
 156 static int __init rootwait_setup(char *str)
 157 {
 158         if (*str)
 159                 return 0;
 160         root_wait = 1;
 161         return 1;
 162 }
 163
 164 __setup("rootwait", rootwait_setup);
 165
 166 static char * __initdata root_mount_data;
 167 static int __init root_data_setup(char *str)
 168 {
 169         root_mount_data = str;
 170         return 1;
 171 }
 172
 173 static char * __initdata root_fs_names;
 174 static int __init fs_names_setup(char *str)
 175 {
 176         root_fs_names = str;
 177         return 1;
 178 }
 179
 180 static unsigned int __initdata root_delay;
 181 static int __init root_delay_setup(char *str)
 182 {
 183         root_delay = simple_strtoul(str, NULL, 0);
 184         return 1;
 185 }
 186
 187 __setup("rootflags=", root_data_setup);
 188 __setup("rootfstype=", fs_names_setup);
 189 __setup("rootdelay=", root_delay_setup);
 190
 191 static void __init get_fs_names(char *page)
 192 {
 193         char *s = page;
 194
 195         if (root_fs_names) {
 196                 strcpy(page, root_fs_names);
 197                 while (*s++) {
 198                         if (s[-1] == ',')
 199                                 s[-1] = '\0';
 200                 }
 201         } else {
 202                 int len = get_filesystem_list(page);
 203                 char *p, *next;
 204
 205                 page[len] = '\0';
 206                 for (p = page-1; p; p = next) {
 207                         next = strchr(++p, '\n');
 208                         if (*p++ != '\t')
 209                                 continue;
 210                         while ((*s++ = *p++) != '\n')
 211                                 ;
 212                         s[-1] = '\0';
 213                 }
 214         }
 215         *s = '\0';
 216 }
 217
 218 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 219 {
 220         int err = sys_mount(name, "/root", fs, flags, data);
 221         if (err)
 222                 return err;
 223
 224         sys_chdir("/root");
 225         ROOT_DEV = current->fs->pwd.mnt->mnt_sb->s_dev;
 226         printk("VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
 227                current->fs->pwd.mnt->mnt_sb->s_type->name,
 228                current->fs->pwd.mnt->mnt_sb->s_flags & MS_RDONLY ?
 229                " readonly" : "", MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
 230         return 0;
 231 }
 232
 233 void __init mount_block_root(char *name, int flags)
 234 {
 235         char *fs_names = __getname_gfp(GFP_KERNEL
 236                 | __GFP_NOTRACK_FALSE_POSITIVE);
 237         char *p;
 238 #ifdef CONFIG_BLOCK
 239         char b[BDEVNAME_SIZE];
 240 #else
 241         const char *b = name;
 242 #endif
 243
 244         get_fs_names(fs_names);
 245 retry:
 246         for (p = fs_names; *p; p += strlen(p)+1) {
 247                 int err = do_mount_root(name, p, flags, root_mount_data);
 248                 switch (err) {
 249                         case 0:
 250                                 goto out;
 251                         case -EACCES:
 252                                 flags |= MS_RDONLY;
 253                                 goto retry;
 254                         case -EINVAL:
 255                                 continue;
 256                 }
 257                 /*
 258                  * Allow the user to distinguish between failed sys_open
 259                  * and bad superblock on root device.
 260                  * and give them a list of the available devices
 261                  */
 262 #ifdef CONFIG_BLOCK
 263                 __bdevname(ROOT_DEV, b);
 264 #endif
 265                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 266                                 root_device_name, b);
 267                 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
 268
 269                 printk_all_partitions();
 270 #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
 271                 printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
 272                        "explicit textual name for \"root=\" boot option.\n");
 273 #endif
 274                 panic("VFS: Unable to mount root fs on %s", b);
 275         }
 276
 277         printk("List of all partitions:\n");
 278         printk_all_partitions();
 279         printk("No filesystem could mount root, tried: ");
 280         for (p = fs_names; *p; p += strlen(p)+1)
 281                 printk(" %s", p);
 282         printk("\n");
 283 #ifdef CONFIG_BLOCK
 284         __bdevname(ROOT_DEV, b);
 285 #endif
 286         panic("VFS: Unable to mount root fs on %s", b);
 287 out:
 288         putname(fs_names);
 289 }
 290
 291 #ifdef CONFIG_ROOT_NFS
 292 static int __init mount_nfs_root(void)
 293 {
 294         void *data = nfs_root_data();
 295
 296         create_dev("/dev/root", ROOT_DEV);
 297         if (data &&
 298             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 299                 return 1;
 300         return 0;
 301 }
 302 #endif
 303
 304 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 305 void __init change_floppy(char *fmt, ...)
 306 {
 307         struct termios termios;
 308         char buf[80];
 309         char c;
 310         int fd;
 311         va_list args;
 312         va_start(args, fmt);
 313         vsprintf(buf, fmt, args);
 314         va_end(args);
 315         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 316         if (fd >= 0) {
 317                 sys_ioctl(fd, FDEJECT, 0);
 318                 sys_close(fd);
 319         }
 320         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 321         fd = sys_open("/dev/console", O_RDWR, 0);
 322         if (fd >= 0) {
 323                 sys_ioctl(fd, TCGETS, (long)&termios);
 324                 termios.c_lflag &= ~ICANON;
 325                 sys_ioctl(fd, TCSETSF, (long)&termios);
 326                 sys_read(fd, &c, 1);
 327                 termios.c_lflag |= ICANON;
 328                 sys_ioctl(fd, TCSETSF, (long)&termios);
 329                 sys_close(fd);
 330         }
 331 }
 332 #endif
 333
 334 void __init mount_root(void)
 335 {
 336 #ifdef CONFIG_ROOT_NFS
 337         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 338                 if (mount_nfs_root())
 339                         return;
 340
 341                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 342                 ROOT_DEV = Root_FD0;
 343         }
 344 #endif
 345 #ifdef CONFIG_BLK_DEV_FD
 346         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 347                 /* rd_doload is 2 for a dual initrd/ramload setup */
 348                 if (rd_doload==2) {
 349                         if (rd_load_disk(1)) {
 350                                 ROOT_DEV = Root_RAM1;
 351                                 root_device_name = NULL;
 352                         }
 353                 } else
 354                         change_floppy("root floppy");
 355         }
 356 #endif
 357 #ifdef CONFIG_BLOCK
 358         create_dev("/dev/root", ROOT_DEV);
 359         mount_block_root("/dev/root", root_mountflags);
 360 #endif
 361 }
 362
 363 /*
 364  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 365  */
 366 void __init prepare_namespace(void)
 367 {
 368         int is_floppy;
 369
 370         if (root_delay) {
 371                 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
 372                        root_delay);
 373                 ssleep(root_delay);
 374         }
 375
 376         /*
 377          * wait for the known devices to complete their probing
 378          *
 379          * Note: this is a potential source of long boot delays.
 380          * For example, it is not atypical to wait 5 seconds here
 381          * for the touchpad of a laptop to initialize.
 382          */
 383         wait_for_device_probe();
 384
 385         md_run_setup();
 386
 387         if (saved_root_name[0]) {
 388                 root_device_name = saved_root_name;
 389                 if (!strncmp(root_device_name, "mtd", 3) ||
 390                     !strncmp(root_device_name, "ubi", 3)) {
 391                         mount_block_root(root_device_name, root_mountflags);
 392                         goto out;
 393                 }
 394                 ROOT_DEV = name_to_dev_t(root_device_name);
 395                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 396                         root_device_name += 5;
 397         }
 398
 399         if (initrd_load())
 400                 goto out;
 401
 402         /* wait for any asynchronous scanning to complete */
 403         if ((ROOT_DEV == 0) && root_wait) {
 404                 printk(KERN_INFO "Waiting for root device %s...\n",
 405                         saved_root_name);
 406                 while (driver_probe_done() != 0 ||
 407                         (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
 408                         msleep(100);
 409                 async_synchronize_full();
 410         }
 411
 412         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 413
 414         if (is_floppy && rd_doload && rd_load_disk(0))
 415                 ROOT_DEV = Root_RAM0;
 416
 417         mount_root();
 418 out:
 419         devtmpfs_mount("dev");
 420         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 421         sys_chroot(".");
 422 }