uiomove question

[Anindya Mukherjee]

An example of the usage I am talking about:

xxx_write(...)
{
...
amount = MIN(uio->uio_resid,  // 0. This is the no of bytes in the uio left to write
             (BUFFER_SIZE - 1 - uio->uio_offset > 0) ?
             BUFFER_SIZE - 1 - uio->uio_offset : 0); // 1. amount to write is computed
//assuming write will happen at uio_offset in sc_buffer
if (amount == 0)
  return (error);
error = uiomove(sc->sc_buffer, amount, uio);  // 2. sc_buffer is not offset
...
}

xxx_read(...)
{
...
amount = MIN(uio->uio_resid,
             (sc->sc_length - uio->uio_offset > 0) ?
             sc->sc_length - uio->uio_offset : 0); // 3. Same as comment 1 above
error = uiomove(sc->sc_buffer + uio->uio_offset, amount, uio); // 4. Here buffer is offset
...
}

Anindya