Re: [patch] only update dcache after write succeeds

[Doug Evans <dje@google.com>]

On Mon, Sep 14, 2009 at 1:20 PM, Michael Snyder<msnyder@vmware.com> wrote:
>> IOW, if some target method does return > 0, then the write succeeded,
>> right?
>> Are there different kinds of "success" in effect here?
>
> Well, maybe only in our case.  ;-)
>
> If nobody else has any worries about it, I'm OK with it.
>
> ----
> * In our case (process record), it's a bad thing for the target
> beneath to be called after the user has said "no".

Righto.
But that seems like a separate issue (albeit one that collides with
dcache here).
We need a way for a target to say "I'm not handling this, and neither
can you." :-)
AIUI, right now it's done by punting with error (which doesn't seem
all that bad for the particular case at hand).
The alternative is to extend the error return values to mean different
things, but I'm guessing we're not in a rush to do that.

If you like, I don't mind a workaround where we invalidate lines just
written to instead of updating them.