readlink_copy
return readlink_copy(buffer, buflen, inode->i_link, inode->i_linklen);
res = readlink_copy(buffer, buflen, link, strlen(link));
res = readlink_copy(buffer, buflen, link, strlen(link));
res = readlink_copy(buffer, buflen, name, strlen(name));
extern int readlink_copy(char __user *, int, const char *, int);
res = readlink_copy(buffer, buflen, name, strlen(name));