init/do_mounts.c - maze/linux - Git at Google

 #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_VERBOSE;
 char * __initdata root_device_name;
 static char __initdata saved_root_name[64];

 /* this is initialized in init/main.c */
 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);
 	}
 	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;
 		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 ();
 }
	#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_VERBOSE;
	char * __initdata root_device_name;
	static char __initdata saved_root_name[64];

	/* this is initialized in init/main.c */
	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);
	}
	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;
	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 ();
	}