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
  15 #include <linux/nfs_fs.h>
  16 #include <linux/nfs_fs_sb.h>
  17 #include <linux/nfs_mount.h>
  18
  19 #include "do_mounts.h"
  20
  21 extern int get_filesystem_list(char * buf);
  22
  23 int __initdata rd_doload;       /* 1 = load RAM disk, 0 = don't load */
  24
  25 int root_mountflags = MS_RDONLY | MS_SILENT;
  26 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
  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);
 111         if (res)
 112                 goto done;
 113
 114 fail:
 115         return 0;
 116 done:
 117         return res;
 118 }
 119
 120 static int __init root_dev_setup(char *line)
 121 {
 122         strlcpy(saved_root_name, line, sizeof(saved_root_name));
 123         return 1;
 124 }
 125
 126 __setup("root=", root_dev_setup);
 127
 128 static int __init rootwait_setup(char *str)
 129 {
 130         if (*str)
 131                 return 0;
 132         root_wait = 1;
 133         return 1;
 134 }
 135
 136 __setup("rootwait", rootwait_setup);
 137
 138 static char * __initdata root_mount_data;
 139 static int __init root_data_setup(char *str)
 140 {
 141         root_mount_data = str;
 142         return 1;
 143 }
 144
 145 static char * __initdata root_fs_names;
 146 static int __init fs_names_setup(char *str)
 147 {
 148         root_fs_names = str;
 149         return 1;
 150 }
 151
 152 static unsigned int __initdata root_delay;
 153 static int __init root_delay_setup(char *str)
 154 {
 155         root_delay = simple_strtoul(str, NULL, 0);
 156         return 1;
 157 }
 158
 159 __setup("rootflags=", root_data_setup);
 160 __setup("rootfstype=", fs_names_setup);
 161 __setup("rootdelay=", root_delay_setup);
 162
 163 static void __init get_fs_names(char *page)
 164 {
 165         char *s = page;
 166
 167         if (root_fs_names) {
 168                 strcpy(page, root_fs_names);
 169                 while (*s++) {
 170                         if (s[-1] == ',')
 171                                 s[-1] = '\0';
 172                 }
 173         } else {
 174                 int len = get_filesystem_list(page);
 175                 char *p, *next;
 176
 177                 page[len] = '\0';
 178                 for (p = page-1; p; p = next) {
 179                         next = strchr(++p, '\n');
 180                         if (*p++ != '\t')
 181                                 continue;
 182                         while ((*s++ = *p++) != '\n')
 183                                 ;
 184                         s[-1] = '\0';
 185                 }
 186         }
 187         *s = '\0';
 188 }
 189
 190 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 191 {
 192         int err = sys_mount(name, "/root", fs, flags, data);
 193         if (err)
 194                 return err;
 195
 196         sys_chdir("/root");
 197         ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
 198         printk("VFS: Mounted root (%s filesystem)%s.\n",
 199                current->fs->pwdmnt->mnt_sb->s_type->name,
 200                current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
 201                " readonly" : "");
 202         return 0;
 203 }
 204
 205 void __init mount_block_root(char *name, int flags)
 206 {
 207         char *fs_names = __getname();
 208         char *p;
 209 #ifdef CONFIG_BLOCK
 210         char b[BDEVNAME_SIZE];
 211 #else
 212         const char *b = name;
 213 #endif
 214
 215         get_fs_names(fs_names);
 216 retry:
 217         for (p = fs_names; *p; p += strlen(p)+1) {
 218                 int err = do_mount_root(name, p, flags, root_mount_data);
 219                 switch (err) {
 220                         case 0:
 221                                 goto out;
 222                         case -EACCES:
 223                                 flags |= MS_RDONLY;
 224                                 goto retry;
 225                         case -EINVAL:
 226                                 continue;
 227                 }
 228                 /*
 229                  * Allow the user to distinguish between failed sys_open
 230                  * and bad superblock on root device.
 231                  * and give them a list of the available devices
 232                  */
 233 #ifdef CONFIG_BLOCK
 234                 __bdevname(ROOT_DEV, b);
 235 #endif
 236                 printk("VFS: Cannot open root device \"%s\" or %s\n",
 237                                 root_device_name, b);
 238                 printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
 239
 240                 printk_all_partitions();
 241                 panic("VFS: Unable to mount root fs on %s", b);
 242         }
 243
 244         printk("List of all partitions:\n");
 245         printk_all_partitions();
 246         printk("No filesystem could mount root, tried: ");
 247         for (p = fs_names; *p; p += strlen(p)+1)
 248                 printk(" %s", p);
 249         printk("\n");
 250 #ifdef CONFIG_BLOCK
 251         __bdevname(ROOT_DEV, b);
 252 #endif
 253         panic("VFS: Unable to mount root fs on %s", b);
 254 out:
 255         putname(fs_names);
 256 }
 257
 258 #ifdef CONFIG_ROOT_NFS
 259 static int __init mount_nfs_root(void)
 260 {
 261         void *data = nfs_root_data();
 262
 263         create_dev("/dev/root", ROOT_DEV);
 264         if (data &&
 265             do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
 266                 return 1;
 267         return 0;
 268 }
 269 #endif
 270
 271 #if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
 272 void __init change_floppy(char *fmt, ...)
 273 {
 274         struct termios termios;
 275         char buf[80];
 276         char c;
 277         int fd;
 278         va_list args;
 279         va_start(args, fmt);
 280         vsprintf(buf, fmt, args);
 281         va_end(args);
 282         fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
 283         if (fd >= 0) {
 284                 sys_ioctl(fd, FDEJECT, 0);
 285                 sys_close(fd);
 286         }
 287         printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
 288         fd = sys_open("/dev/console", O_RDWR, 0);
 289         if (fd >= 0) {
 290                 sys_ioctl(fd, TCGETS, (long)&termios);
 291                 termios.c_lflag &= ~ICANON;
 292                 sys_ioctl(fd, TCSETSF, (long)&termios);
 293                 sys_read(fd, &c, 1);
 294                 termios.c_lflag |= ICANON;
 295                 sys_ioctl(fd, TCSETSF, (long)&termios);
 296                 sys_close(fd);
 297         }
 298 }
 299 #endif
 300
 301 void __init mount_root(void)
 302 {
 303 #ifdef CONFIG_ROOT_NFS
 304         if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
 305                 if (mount_nfs_root())
 306                         return;
 307
 308                 printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
 309                 ROOT_DEV = Root_FD0;
 310         }
 311 #endif
 312 #ifdef CONFIG_BLK_DEV_FD
 313         if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
 314                 /* rd_doload is 2 for a dual initrd/ramload setup */
 315                 if (rd_doload==2) {
 316                         if (rd_load_disk(1)) {
 317                                 ROOT_DEV = Root_RAM1;
 318                                 root_device_name = NULL;
 319                         }
 320                 } else
 321                         change_floppy("root floppy");
 322         }
 323 #endif
 324 #ifdef CONFIG_BLOCK
 325         create_dev("/dev/root", ROOT_DEV);
 326         mount_block_root("/dev/root", root_mountflags);
 327 #endif
 328 }
 329
 330 /*
 331  * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
 332  */
 333 void __init prepare_namespace(void)
 334 {
 335         int is_floppy;
 336
 337         if (root_delay) {
 338                 printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
 339                        root_delay);
 340                 ssleep(root_delay);
 341         }
 342
 343         /* wait for the known devices to complete their probing */
 344         while (driver_probe_done() != 0)
 345                 msleep(100);
 346
 347         md_run_setup();
 348
 349         if (saved_root_name[0]) {
 350                 root_device_name = saved_root_name;
 351                 if (!strncmp(root_device_name, "mtd", 3)) {
 352                         mount_block_root(root_device_name, root_mountflags);
 353                         goto out;
 354                 }
 355                 ROOT_DEV = name_to_dev_t(root_device_name);
 356                 if (strncmp(root_device_name, "/dev/", 5) == 0)
 357                         root_device_name += 5;
 358         }
 359
 360         if (initrd_load())
 361                 goto out;
 362
 363         /* wait for any asynchronous scanning to complete */
 364         if ((ROOT_DEV == 0) && root_wait) {
 365                 printk(KERN_INFO "Waiting for root device %s...\n",
 366                         saved_root_name);
 367                 while (driver_probe_done() != 0 ||
 368                         (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
 369                         msleep(100);
 370         }
 371
 372         is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
 373
 374         if (is_floppy && rd_doload && rd_load_disk(0))
 375                 ROOT_DEV = Root_RAM0;
 376
 377         mount_root();
 378 out:
 379         sys_mount(".", "/", NULL, MS_MOVE, NULL);
 380         sys_chroot(".");
 381         security_sb_post_mountroot();
 382 }
 383