Re: floppy driver 2.6.3 question

From: Peter T. Breuer
Date: Thu Mar 18 2004 - 13:14:24 EST


"Also sprach Jens Axboe:"
> > I mean that I thought that if ->flags & REQ_SPECIAL were set, then
> > we were obliged to flush the driver request queue before treating
> > this request, and I also thought that the driver was liable to receive
> > such things from somewhere else.
>
> I dunno where you get those crazy ideas, REQ_SPECIAL has absolutely
> nothing to do with that.

Sorry about that. Perhaps I saw it in 2.5.


> You may use REQ_SPECIAL bit as you see fit, and ->special as well. You
> don't have to use them together, must do though. However, as I said
> earlier, if you push these requests on to someone else request queue,
> you must not fiddle with REQ_SPECIAL and/or ->special. In that case you
> cannot touch/use more than what the block layer already does.

Well hooray. All seems to be working fine now that I shifted the burden
to ->special and stopped playing with ->flags (touch wood). Even
revalidation is working AOK as far as I can tell. I'll reenable that
read of the first block a-la-floppy to see if it causes some extra magic.

Many thanks!


> > Are you going to say, set REQ_SPECIAL on everything and add all the
> > real request info and a bit more to ->special? I suspect you are!
>
> That's where to put it, indeed. But if you pass it on...


Peter
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