tag	line	file	source code
IO_fn_t	200	fs/read_write.c	typedef int (*IO_fn_t)(struct inode *, struct file *, char *, int);
IO_fn_t	208	fs/read_write.c	IO_fn_t fn;
IO_fn_t	248	fs/read_write.c	fn = (IO_fn_t) file->f_op->write;