mapping of inode and file structure in Open System call

Hi, I have a question regarding open systemcall "open(dev_name, O_RDWR, 0)" -->userspace suppose devname is /dev/my_device Now when we look into open file operation, we have prototype "int (*open) (struct inode *, struct file *);" could anyone tell me how inode and file structure pointer are filled. I think logic is written in fs/open.c but i got confused in callbacks used in it.could anyone please tell me which topics should i cover to understand open system call. Thanks.