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