linux-master/kernel/relay.c

458  *	@subbuf_size: size of sub-buffers
476 			 size_t subbuf_size,
485 	if (!(subbuf_size && n_subbufs))
487 	if (subbuf_size > UINT_MAX / n_subbufs)
504 	chan->subbuf_size = subbuf_size;
505 	chan->alloc_size = PAGE_ALIGN(subbuf_size * n_subbufs);
664 	if (unlikely(length > buf->chan->subbuf_size))
667 	if (buf->offset != buf->chan->subbuf_size + 1) {
668 		buf->prev_padding = buf->chan->subbuf_size - buf->offset;
674 				buf->chan->subbuf_size -
677 			buf->early_bytes += buf->chan->subbuf_size -
693 	new = buf->start + new_subbuf * buf->chan->subbuf_size;
696 		buf->offset = buf->chan->subbuf_size + 1;
702 	if (unlikely(length + buf->offset > buf->chan->subbuf_size))
771 		       chan->last_toobig, chan->subbuf_size);
882 	size_t subbuf_size = buf->chan->subbuf_size;
890 	if (buf->bytes_consumed + bytes_consumed > subbuf_size) {
899 		read_subbuf = read_pos / buf->chan->subbuf_size;
900 	if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) {
902 		    (buf->offset == subbuf_size))
914 	size_t subbuf_size = buf->chan->subbuf_size;
923 	if (unlikely(buf->offset > subbuf_size)) {
935 	produced = (produced % n_subbufs) * subbuf_size + buf->offset;
936 	consumed = (consumed % n_subbufs) * subbuf_size + buf->bytes_consumed;
939 		produced += n_subbufs * subbuf_size;
942 		if (buf->offset == subbuf_size &&
961 	size_t subbuf_size = buf->chan->subbuf_size;
963 	write_subbuf = (buf->data - buf->start) / subbuf_size;
964 	write_offset = buf->offset > subbuf_size ? subbuf_size : buf->offset;
965 	read_subbuf = read_pos / subbuf_size;
966 	read_offset = read_pos % subbuf_size;
973 		avail = (subbuf_size - padding) - read_offset;
989 	size_t subbuf_size = buf->chan->subbuf_size;
992 	size_t read_pos = (consumed * subbuf_size + buf->bytes_consumed)
993 			% (n_subbufs * subbuf_size);
995 	read_subbuf = read_pos / subbuf_size;
997 	padding_start = (read_subbuf + 1) * subbuf_size - padding;
998 	padding_end = (read_subbuf + 1) * subbuf_size;
1001 		read_pos = read_subbuf * subbuf_size;
1018 	size_t subbuf_size = buf->chan->subbuf_size;
1021 	read_subbuf = read_pos / subbuf_size;
1023 	if (read_pos % subbuf_size + count + padding == subbuf_size)
1024 		end_pos = (read_subbuf + 1) * subbuf_size;
1027 	if (end_pos >= subbuf_size * n_subbufs)