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