Re: [PATCH] 2.4.x write barriers (updated for ext3)

Stephen C. Tweedie
2002-03-11T11:36:04Z

Hi,

On Sun, Mar 10, 2002 at 12:24:12AM -0500, Douglas Gilbert wrote:

> > FUA is not available on WRITE6, only WRITE10 or WRITE12 commands.
>
> Stephen,
> FUA is also available on WRITE16.

I said WRITE6, not WRITE16. :-) WRITE6 uses the low 5 bits of the LUN
byte for the top bits of the block number; WRITE10 and later use those
5 bits for DPO/FUA etc. But WRITE6 is a horribly limited interface:
you only have 21 bits of block number for a start, so it's limited to
1GB on 512-byte-sector devices. We can probably ignore WRITE6 safely
enough.

--Stephen