linux/init/do_mounts.c
Joern Engel e9482b4374 [MTD] Allow alternate JFFS2 mount variant for root filesystem.
With this patch, "root=mtd3" and "root=mtd:foo" work for a JFFS2 rootfs.

Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
2006-05-30 14:25:46 +02:00

437 lines
9.2 KiB
C

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/fd.h>
#include <linux/tty.h>
#include <linux/suspend.h>
#include <linux/root_dev.h>
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/mount.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
#include "do_mounts.h"
extern int get_filesystem_list(char * buf);
int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
int root_mountflags = MS_RDONLY | MS_SILENT;
char * __initdata root_device_name;
static char __initdata saved_root_name[64];
dev_t ROOT_DEV;
static int __init load_ramdisk(char *str)
{
rd_doload = simple_strtol(str,NULL,0) & 3;
return 1;
}
__setup("load_ramdisk=", load_ramdisk);
static int __init readonly(char *str)
{
if (*str)
return 0;
root_mountflags |= MS_RDONLY;
return 1;
}
static int __init readwrite(char *str)
{
if (*str)
return 0;
root_mountflags &= ~MS_RDONLY;
return 1;
}
__setup("ro", readonly);
__setup("rw", readwrite);
static dev_t try_name(char *name, int part)
{
char path[64];
char buf[32];
int range;
dev_t res;
char *s;
int len;
int fd;
unsigned int maj, min;
/* read device number from .../dev */
sprintf(path, "/sys/block/%s/dev", name);
fd = sys_open(path, 0, 0);
if (fd < 0)
goto fail;
len = sys_read(fd, buf, 32);
sys_close(fd);
if (len <= 0 || len == 32 || buf[len - 1] != '\n')
goto fail;
buf[len - 1] = '\0';
if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
/*
* Try the %u:%u format -- see print_dev_t()
*/
res = MKDEV(maj, min);
if (maj != MAJOR(res) || min != MINOR(res))
goto fail;
} else {
/*
* Nope. Try old-style "0321"
*/
res = new_decode_dev(simple_strtoul(buf, &s, 16));
if (*s)
goto fail;
}
/* if it's there and we are not looking for a partition - that's it */
if (!part)
return res;
/* otherwise read range from .../range */
sprintf(path, "/sys/block/%s/range", name);
fd = sys_open(path, 0, 0);
if (fd < 0)
goto fail;
len = sys_read(fd, buf, 32);
sys_close(fd);
if (len <= 0 || len == 32 || buf[len - 1] != '\n')
goto fail;
buf[len - 1] = '\0';
range = simple_strtoul(buf, &s, 10);
if (*s)
goto fail;
/* if partition is within range - we got it */
if (part < range)
return res + part;
fail:
return 0;
}
/*
* Convert a name into device number. We accept the following variants:
*
* 1) device number in hexadecimal represents itself
* 2) /dev/nfs represents Root_NFS (0xff)
* 3) /dev/<disk_name> represents the device number of disk
* 4) /dev/<disk_name><decimal> represents the device number
* of partition - device number of disk plus the partition number
* 5) /dev/<disk_name>p<decimal> - same as the above, that form is
* used when disk name of partitioned disk ends on a digit.
*
* If name doesn't have fall into the categories above, we return 0.
* Sysfs is used to check if something is a disk name - it has
* all known disks under bus/block/devices. If the disk name
* contains slashes, name of sysfs node has them replaced with
* bangs. try_name() does the actual checks, assuming that sysfs
* is mounted on rootfs /sys.
*/
dev_t name_to_dev_t(char *name)
{
char s[32];
char *p;
dev_t res = 0;
int part;
#ifdef CONFIG_SYSFS
int mkdir_err = sys_mkdir("/sys", 0700);
if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
goto out;
#endif
if (strncmp(name, "/dev/", 5) != 0) {
unsigned maj, min;
if (sscanf(name, "%u:%u", &maj, &min) == 2) {
res = MKDEV(maj, min);
if (maj != MAJOR(res) || min != MINOR(res))
goto fail;
} else {
res = new_decode_dev(simple_strtoul(name, &p, 16));
if (*p)
goto fail;
}
goto done;
}
name += 5;
res = Root_NFS;
if (strcmp(name, "nfs") == 0)
goto done;
res = Root_RAM0;
if (strcmp(name, "ram") == 0)
goto done;
if (strlen(name) > 31)
goto fail;
strcpy(s, name);
for (p = s; *p; p++)
if (*p == '/')
*p = '!';
res = try_name(s, 0);
if (res)
goto done;
while (p > s && isdigit(p[-1]))
p--;
if (p == s || !*p || *p == '0')
goto fail;
part = simple_strtoul(p, NULL, 10);
*p = '\0';
res = try_name(s, part);
if (res)
goto done;
if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
goto fail;
p[-1] = '\0';
res = try_name(s, part);
done:
#ifdef CONFIG_SYSFS
sys_umount("/sys", 0);
out:
if (!mkdir_err)
sys_rmdir("/sys");
#endif
return res;
fail:
res = 0;
goto done;
}
static int __init root_dev_setup(char *line)
{
strlcpy(saved_root_name, line, sizeof(saved_root_name));
return 1;
}
__setup("root=", root_dev_setup);
static char * __initdata root_mount_data;
static int __init root_data_setup(char *str)
{
root_mount_data = str;
return 1;
}
static char * __initdata root_fs_names;
static int __init fs_names_setup(char *str)
{
root_fs_names = str;
return 1;
}
static unsigned int __initdata root_delay;
static int __init root_delay_setup(char *str)
{
root_delay = simple_strtoul(str, NULL, 0);
return 1;
}
__setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);
static void __init get_fs_names(char *page)
{
char *s = page;
if (root_fs_names) {
strcpy(page, root_fs_names);
while (*s++) {
if (s[-1] == ',')
s[-1] = '\0';
}
} else {
int len = get_filesystem_list(page);
char *p, *next;
page[len] = '\0';
for (p = page-1; p; p = next) {
next = strchr(++p, '\n');
if (*p++ != '\t')
continue;
while ((*s++ = *p++) != '\n')
;
s[-1] = '\0';
}
}
*s = '\0';
}
static int __init do_mount_root(char *name, char *fs, int flags, void *data)
{
int err = sys_mount(name, "/root", fs, flags, data);
if (err)
return err;
sys_chdir("/root");
ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
printk("VFS: Mounted root (%s filesystem)%s.\n",
current->fs->pwdmnt->mnt_sb->s_type->name,
current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ?
" readonly" : "");
return 0;
}
void __init mount_block_root(char *name, int flags)
{
char *fs_names = __getname();
char *p;
char b[BDEVNAME_SIZE];
get_fs_names(fs_names);
retry:
for (p = fs_names; *p; p += strlen(p)+1) {
int err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
goto out;
case -EACCES:
flags |= MS_RDONLY;
goto retry;
case -EINVAL:
continue;
}
/*
* Allow the user to distinguish between failed sys_open
* and bad superblock on root device.
*/
__bdevname(ROOT_DEV, b);
printk("VFS: Cannot open root device \"%s\" or %s\n",
root_device_name, b);
printk("Please append a correct \"root=\" boot option\n");
panic("VFS: Unable to mount root fs on %s", b);
}
printk("No filesystem could mount root, tried: ");
for (p = fs_names; *p; p += strlen(p)+1)
printk(" %s", p);
printk("\n");
panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, b));
out:
putname(fs_names);
}
#ifdef CONFIG_ROOT_NFS
static int __init mount_nfs_root(void)
{
void *data = nfs_root_data();
create_dev("/dev/root", ROOT_DEV, NULL);
if (data &&
do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
return 1;
return 0;
}
#endif
#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
void __init change_floppy(char *fmt, ...)
{
struct termios termios;
char buf[80];
char c;
int fd;
va_list args;
va_start(args, fmt);
vsprintf(buf, fmt, args);
va_end(args);
fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
if (fd >= 0) {
sys_ioctl(fd, FDEJECT, 0);
sys_close(fd);
}
printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
fd = sys_open("/dev/console", O_RDWR, 0);
if (fd >= 0) {
sys_ioctl(fd, TCGETS, (long)&termios);
termios.c_lflag &= ~ICANON;
sys_ioctl(fd, TCSETSF, (long)&termios);
sys_read(fd, &c, 1);
termios.c_lflag |= ICANON;
sys_ioctl(fd, TCSETSF, (long)&termios);
sys_close(fd);
}
}
#endif
void __init mount_root(void)
{
#ifdef CONFIG_ROOT_NFS
if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
if (mount_nfs_root())
return;
printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
ROOT_DEV = Root_FD0;
}
#endif
#ifdef CONFIG_BLK_DEV_FD
if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
/* rd_doload is 2 for a dual initrd/ramload setup */
if (rd_doload==2) {
if (rd_load_disk(1)) {
ROOT_DEV = Root_RAM1;
root_device_name = NULL;
}
} else
change_floppy("root floppy");
}
#endif
create_dev("/dev/root", ROOT_DEV, root_device_name);
mount_block_root("/dev/root", root_mountflags);
}
/*
* Prepare the namespace - decide what/where to mount, load ramdisks, etc.
*/
void __init prepare_namespace(void)
{
int is_floppy;
mount_devfs();
if (root_delay) {
printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
root_delay);
ssleep(root_delay);
}
md_run_setup();
if (saved_root_name[0]) {
root_device_name = saved_root_name;
if (!strncmp(root_device_name, "mtd", 3)) {
mount_block_root(root_device_name, root_mountflags);
goto out;
}
ROOT_DEV = name_to_dev_t(root_device_name);
if (strncmp(root_device_name, "/dev/", 5) == 0)
root_device_name += 5;
}
is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
if (initrd_load())
goto out;
if (is_floppy && rd_doload && rd_load_disk(0))
ROOT_DEV = Root_RAM0;
mount_root();
out:
umount_devfs("/dev");
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot(".");
security_sb_post_mountroot();
mount_devfs_fs ();
}