pipe_buf
rem += pipe_buf(pipe, idx)->len;
ibuf = pipe_buf(pipe, tail);
struct pipe_buffer *buf = pipe_buf(pipe, tail);
struct pipe_buffer *buf = pipe_buf(pipe, head - 1);
buf = pipe_buf(pipe, head);
count += pipe_buf(pipe, tail)->len;
ibuf = pipe_buf(ipipe, i_tail);
obuf = pipe_buf(opipe, o_head);
ibuf = pipe_buf(ipipe, i_tail);
obuf = pipe_buf(opipe, o_head);
struct pipe_buffer *buf = pipe_buf(pipe, head);
*pipe_buf(pipe, head) = *buf;
struct pipe_buffer *buf = pipe_buf(pipe, tail);
struct pipe_buffer *buf = pipe_buf(pipe, tail);
struct pipe_buffer *buf = pipe_buf(pipe, tail);
struct pipe_buffer *buf = pipe_buf(pipe, tail);
struct pipe_buffer *buf = pipe_buf(pipe, tail);
struct pipe_buffer *buf = pipe_buf(pipe, tail);
return pipe_buf(pipe, pipe->head);
buf = pipe_buf(pipe, head);
buf = pipe_buf(pipe, head - 1);