#include <linux/kernel.h>#include <linux/dirent.h>#include <linux/string.h> #include "do_mounts.h" void __init mount_devfs(void){	sys_mount("devfs", "/dev", "devfs", 0, NULL);} void __init umount_devfs(char *path){	sys_umount(path, 0);} /* * If the dir will fit in *buf, return its length.  If it won't fit, return * zero.  Return -ve on error. */static int __init do_read_dir(int fd, void *buf, int len){	long bytes, n;	char *p = buf;	sys_lseek(fd, 0, 0); 	for (bytes = 0; bytes < len; bytes += n) {		n = sys_getdents64(fd, (struct linux_dirent64 *)(p + bytes),					len - bytes);		if (n < 0)			return n;		if (n == 0)			return bytes;	}	return 0;} /* * Try to read all of a directory.  Returns the contents at *p, which * is kmalloced memory.  Returns the number of bytes read at *len.  Returns * NULL on error. */static void * __init read_dir(char *path, int *len){	int size;	int fd = sys_open(path, 0, 0); 	*len = 0;	if (fd < 0)		return NULL; 	for (size = 1 << 9; size <= (PAGE_SIZE << MAX_ORDER); size <<= 1) {		void *p = kmalloc(size, GFP_KERNEL);		int n;		if (!p)			break;		n = do_read_dir(fd, p, size);		if (n > 0) {			sys_close(fd);			*len = n;			return p;		}		kfree(p);		if (n == -EINVAL)			continue;	/* Try a larger buffer */		if (n < 0)			break;	}	sys_close(fd);	return NULL;} /* * recursively scan <path>, looking for a device node of type <dev> */static int __init find_in_devfs(char *path, unsigned dev){	char *end = path + strlen(path);	int rest = path + 64 - end;	int size;	char *p = read_dir(path, &size);	char *s; 	if (!p)		return -1;	for (s = p; s < p + size; s += ((struct linux_dirent64 *)s)->d_reclen) {		struct linux_dirent64 *d = (struct linux_dirent64 *)s;		if (strlen(d->d_name) + 2 > rest)			continue;		switch (d->d_type) {			case DT_BLK:				sprintf(end, "/%s", d->d_name);				if (bstat(path) != dev)					break;				kfree(p);				return 0;			case DT_DIR:				if (strcmp(d->d_name, ".") == 0)					break;				if (strcmp(d->d_name, "..") == 0)					break;				sprintf(end, "/%s", d->d_name);				if (find_in_devfs(path, dev) < 0)					break;				kfree(p);				return 0;		}	}	kfree(p);	return -1;} /* * create a device node called <name> which points to * <devfs_name> if possible, otherwise find a device node * which matches <dev> and make <name> a symlink pointing to it. */int __init create_dev(char *name, dev_t dev, char *devfs_name){	char path[64]; 	sys_unlink(name);	if (devfs_name && devfs_name[0]) {		if (strncmp(devfs_name, "/dev/", 5) == 0)			devfs_name += 5;		sprintf(path, "/dev/%s", devfs_name);		if (sys_access(path, 0) == 0)			return sys_symlink(devfs_name, name);	}	if (!dev)		return -1;	strcpy(path, "/dev");	if (find_in_devfs(path, new_encode_dev(dev)) < 0)		return -1;	return sys_symlink(path + 5, name);}