init/do_mounts.c

   1 #include <linux/sched.h>
   2 #include <linux/ctype.h>
   3 #include <linux/fd.h>
   4 #include <linux/tty.h>
   5 #include <linux/suspend.h>
   6 #include <linux/root_dev.h>
   7 #include <linux/security.h>
   8
   9 #include <linux/nfs_fs.h>
  10 #include <linux/nfs_fs_sb.h>
  11 #include <linux/nfs_mount.h>
  12
  13 #include "do_mounts.h"
  14
  15 extern int get_filesystem_list(char * buf);
  16
  17 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  18
  19 int root_mountflags = MS_RDONLY | MS_VERBOSE;
  20 char * __initdata root_device_name;
  21 static char __initdata saved_root_name[64];
  22
  23 /* this is initialized in init/main.c */
  24 dev_t ROOT_DEV;
  25
  26 static int __init load_ramdisk(char *str)
  27 {
  28         rd_doload = simple_strtol(str,NULL,0) & 3;
  29         return 1;
  30 }
  31 __setup("load_ramdisk=", load_ramdisk);
  32
  33 static int __init readonly(char *str)
  34 {
  35         if (*str)
  36                 return 0;
  37         root_mountflags |= MS_RDONLY;
  38         return 1;
  39 }
  40
  41 static int __init readwrite(char *str)
  42 {
  43         if (*str)
  44                 return 0;
  45         root_mountflags &= ~MS_RDONLY;
  46         return 1;
  47 }
  48
  49 __setup("ro", readonly);
  50 __setup("rw", readwrite);
  51
  52 static dev_t __init try_name(char *name, int part)
  53 {
  54         char path[64];
  55         char buf[32];
  56         int range;
  57         dev_t res;
  58         char *s;
  59         int len;
  60         int fd;
  61
  62         /* read device number from .../dev */
  63
  64         sprintf(path, "/sys/block/%s/dev", name);
  65         fd = open(path, 0, 0);
  66         if (fd < 0)
  67                 goto fail;
  68         len = read(fd, buf, 32);
  69         close(fd);
  70         if (len <= 0 || len == 32 || buf[len - 1] != '\n')
  71                 goto fail;
  72         buf[len - 1] = '\0';
  73         res = (dev_t) simple_strtoul(buf, &s, 16);
  74         if (*s)
  75                 goto fail;
  76
  77         /* if it's there and we are not looking for a partition - that's it */
  78         if (!part)
  79                 return res;
  80
  81         /* otherwise read range from .../range */
  82         sprintf(path, "/sys/block/%s/range", name);
  83         fd = open(path, 0, 0);
  84         if (fd < 0)
  85                 goto fail;
  86         len = read(fd, buf, 32);
  87         close(fd);
  88         if (len <= 0 || len == 32 || buf[len - 1] != '\n')
  89                 goto fail;
  90         buf[len - 1] = '\0';
  91         range = simple_strtoul(buf, &s, 10);
  92         if (*s)
  93                 goto fail;
  94
  95         /* if partition is within range - we got it */
  96         if (part < range)
  97                 return res + part;
  98 fail:
  99         return (dev_t) 0;
 100 }
 101
 102 /*
 103  *      Convert a name into device number.  We accept the following variants:
 104  *
 105  *      1) device number in hexadecimal represents itself
 106  *      2) /dev/nfs represents Root_NFS (0xff)
 107  *      3) /dev/<disk_name> represents the device number of disk
 108  *      4) /dev/<disk_name><decimal> represents the device number
 109  *         of partition - device number of disk plus the partition number
 110  *      5) /dev/<disk_name>p<decimal> - same as the above, that form is
 111  *         used when disk name of partitioned disk ends on a digit.
 112  *
 113  *      If name doesn't have fall into the categories above, we return 0.
 114  *      Driverfs is used to check if something is a disk name - it has
 115  *      all known disks under bus/block/devices.  If the disk name
 116  *      contains slashes, name of driverfs node has them replaced with
 117  *      dots.  try_name() does the actual checks, assuming that driverfs
 118  *      is mounted on rootfs /sys.
 119  */
 120
 121 dev_t name_to_dev_t(char *name)
 122 {
 123         char s[32];
 124         char *p;
 125         dev_t res = 0;
 126         int part;
 127
 128         sys_mkdir("/sys", 0700);
 129         if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
 130                 goto out;
 131
 132         if (strncmp(name, "/dev/", 5) != 0) {
 133                 res = (dev_t) simple_strtoul(name, &p, 16);
 134                 if (*p)
 135                         goto fail;
 136                 goto done;
 137         }
 138         name += 5;
 139         res = Root_NFS;
 140         if (strcmp(name, "nfs") == 0)
 141                 goto done;
 142
 143         if (strlen(name) > 31)
 144                 goto fail;
 145         strcpy(s, name);
 146         for (p = s; *p; p++)
 147                 if (*p == '/')
 148                         *p = '.';
 149         res = try_name(s, 0);
 150         if (res)
 151                 goto done;
 152
 153         while (p > s && isdigit(p[-1]))
 154                 p--;
 155         if (p == s || !*p || *p == '0')
 156                 goto fail;
 157         part = simple_strtoul(p, NULL, 10);
 158         *p = '\0';
 159         res = try_name(s, part);
 160         if (res)
 161                 goto done;
 162
 163         if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
 164                 goto fail;
 165         p[-1] = '\0';
 166         res = try_name(s, part);
 167 done:
 168         sys_umount("/sys", 0);
 169 out:
 170         sys_rmdir("/sys");
 171         return res;
 172 fail:
 173         res = (dev_t) 0;
 174         goto done;
 175 }
 176
 177 static int __init root_dev_setup(char *line)
 178 {
 179         strlcpy(saved_root_name, line, sizeof(saved_root_name));
 180         return 1;
 181 }
 182
 183 __setup("root=", root_dev_setup);
 184
 185 static char * __initdata root_mount_data;
 186 static int __init root_data_setup(char *str)
 187 {
 188         root_mount_data = str;
 189         return 1;
 190 }
 191
 192 static char * __initdata root_fs_names;
 193 static int __init fs_names_setup(char *str)
 194 {
 195         root_fs_names = str;
 196         return 1;
 197 }
 198
 199 __setup("rootflags=", root_data_setup);
 200 __setup("rootfstype=", fs_names_setup);
 201
 202 static void __init get_fs_names(char *page)
 203 {
 204         char *s = page;
 205
 206         if (root_fs_names) {
 207                 strcpy(page, root_fs_names);
 208                 while (*s++) {
 209                         if (s[-1] == ',')
 210                                 s[-1] = '\0';
 211                 }
 212         } else {
 213                 int len = get_filesystem_list(page);
 214                 char *p, *next;
 215
 216                 page[len] = '\0';
 217                 for (p = page-1; p; p = next) {
 218                         next = strchr(++p, '\n');
 219                         if (*p++ != '\t')
 220                                 continue;
 221                         while ((*s++ = *p++) != '\n')
 222                                 ;
 223                         s[-1] = '\0';
 224                 }
 225         }
 226         *s = '\0';
 227 }
 228
 229 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 230 {
 231         int err = sys_mount(name, "/root", fs, flags, data);
 232         if (err)
 233                 return err;
 234
 235         sys_chdir("/root");
 236         ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
 237         printk("VFS: Mounted root (%s filesystem)%s.\n",
 238                current->fs->pwdmnt->mnt_sb->s_type->name,
 239                current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
 240                " readonly" : "");
 241         return 0;
 242 }
 243
 244 void __init mount_block_root(char *name, int flags)
 245 {
 246         char *fs_names = __getname();
 247         char *p;
 248         char b[BDEVNAME_SIZE];
 249
 250         get_fs_names(fs_names);
 251 retry:
 252         for (p = fs_names; *p; p += strlen(p)+1) {
 253                 int err = do_mount_root(name, p, flags, root_mount_data);
 254                 switch (err) {
 255                         case 0:
 256                                 goto out;
 257                         case -EACCES:
 258                                 flags |= MS_RDONLY;
 259                                 goto retry;
 260                         case -EINVAL:
 261                                 continue;
 262                 }
 263                 /*
 264                  * Allow the user to distinguish between failed open
 265                  * and bad superblock on root device.
 266                  */
 267                 __bdevname(ROOT_DEV, b);
 268                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 269                                 root_device_name, b);
 270                 printk("Please append a correct \"root=\" boot option\n");
 271                 panic("VFS: Unable to mount root fs on %s", b);
 272         }
 273         panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
 274 out:
 275         putname(fs_names);
 276 }
 277
 278 #ifdef CONFIG_ROOT_NFS
 279 static int __init mount_nfs_root(void)
 280 {
 281         void *data = nfs_root_data();
 282
 283         create_dev("/dev/root", ROOT_DEV, NULL);
 284         if (data &&
 285             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 286                 return 1;
 287         return 0;
 288 }
 289 #endif
 290
 291 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 292 void __init change_floppy(char *fmt, ...)
 293 {
 294         struct termios termios;
 295         char buf[80];
 296         char c;
 297         int fd;
 298         va_list args;
 299         va_start(args, fmt);
 300         vsprintf(buf, fmt, args);
 301         va_end(args);
 302         fd = open("/dev/root", O_RDWR | O_NDELAY, 0);
 303         if (fd >= 0) {
 304                 sys_ioctl(fd, FDEJECT, 0);
 305                 close(fd);
 306         }
 307         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 308         fd = open("/dev/console", O_RDWR, 0);
 309         if (fd >= 0) {
 310                 sys_ioctl(fd, TCGETS, (long)&termios);
 311                 termios.c_lflag &= ~ICANON;
 312                 sys_ioctl(fd, TCSETSF, (long)&termios);
 313                 read(fd, &c, 1);
 314                 termios.c_lflag |= ICANON;
 315                 sys_ioctl(fd, TCSETSF, (long)&termios);
 316                 close(fd);
 317         }
 318 }
 319 #endif
 320
 321 void __init mount_root(void)
 322 {
 323 #ifdef CONFIG_ROOT_NFS
 324         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 325                 if (mount_nfs_root())
 326                         return;
 327
 328                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 329                 ROOT_DEV = Root_FD0;
 330         }
 331 #endif
 332 #ifdef CONFIG_BLK_DEV_FD
 333         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 334                 /* rd_doload is 2 for a dual initrd/ramload setup */
 335                 if (rd_doload==2) {
 336                         if (rd_load_disk(1)) {
 337                                 ROOT_DEV = Root_RAM1;
 338                                 root_device_name = NULL;
 339                         }
 340                 } else
 341                         change_floppy("root floppy");
 342         }
 343 #endif
 344         create_dev("/dev/root", ROOT_DEV, root_device_name);
 345         mount_block_root("/dev/root", root_mountflags);
 346 }
 347
 348 /*
 349  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 350  */
 351 void __init prepare_namespace(void)
 352 {
 353         int is_floppy;
 354
 355         mount_devfs();
 356
 357         md_run_setup();
 358
 359         if (saved_root_name[0]) {
 360                 root_device_name = saved_root_name;
 361                 ROOT_DEV = name_to_dev_t(root_device_name);
 362                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 363                         root_device_name += 5;
 364         }
 365
 366         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 367
 368         /* This has to be before mounting root, because even readonly mount of reiserfs would replay
 369            log corrupting stuff */
 370         software_resume();
 371
 372         if (initrd_load())
 373                 goto out;
 374
 375         if (is_floppy && rd_doload && rd_load_disk(0))
 376                 ROOT_DEV = Root_RAM0;
 377
 378         mount_root();
 379 out:
 380         umount_devfs("/dev");
 381         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 382         sys_chroot(".");
 383         security_sb_post_mountroot();
 384         mount_devfs_fs ();
 385 }
 386