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