Splice data from file to a pipe
ssize_t generic_file_splice_read(struct file * in, loff_t * ppos, struct pipe_inode_info * pipe, size_t len, unsigned int flags);
in
file to splice from
ppos
position in in
pipe
pipe to splice to
len
number of bytes to splice
flags
splice modifier flags
Will read pages from given file and fill them into a pipe. Can be used as long as the address_space operations for the source implements a readpage hook.