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