tag	line	file	source code
FIONREAD	43	fs/ioctl.c	case FIONREAD:
FIONREAD	139	fs/pipe.c	case FIONREAD:
FIONREAD	33	include/linux/termios.h	#define TIOCINQ    FIONREAD
FIONREAD	467	net/inet/tcp.c	case FIONREAD: