DANGER WILL ROBINSON! SERIOUS problem with current 5.4-PRERELEASE - UPDATE

[Karl Denninger]

On Tue, Mar 29, 2005 at 11:43:18PM -0600, Karl Denninger wrote:
> Here's the diff and some thoughts....
> 
> Fs:/usr/src/sys/dev/ata> cvs diff -r 1.32.2.5 ata-queue.c
> Index: ata-queue.c
> ===================================================================
> RCS file: /usr/cvs/src/sys/dev/ata/ata-queue.c,v
> retrieving revision 1.32.2.5
> retrieving revision 1.32.2.6
> diff -r1.32.2.5 -r1.32.2.6
> 30c30
> < __FBSDID("$FreeBSD: src/sys/dev/ata/ata-queue.c,v 1.32.2.5 2004/10/24 09:27:37 sos Exp $");
> ---
> > __FBSDID("$FreeBSD: src/sys/dev/ata/ata-queue.c,v 1.32.2.6 2005/03/23 04:50:26 mdodd Exp $");
> 218a219,221
> >       if (!dumping)
> >           callout_reset(&request->callout, request->timeout * hz,
> >                         (timeout_t*)ata_timeout, request);
> 241,243c244,249
> < 
> <       /* if reinit succeeded and retries still permit, reinject request */
> <       if (ata_reinit(ch) && request->retries-- > 0 && request->device->param){
> ---
> >       /*
> >        * if reinit succeeds, retries still permit and device didn't
> >        * get removed by the reinit, reinject request
> >        */
> >       if (!ata_reinit(ch) && request->retries-- > 0
> >           && request->device->param){
> 245a252
> >           request->donecount = 0;

Removing the second change (changing the test on the "ata_reinit") appears to 
prevent both the destabilization and the actual requeue from taking place 
(that is, you get the immediate disconnect from the array when the error 
occurs; therefore whatever is causing the destabilization doesn't happen.)

I will attempt to remove the first delta alone (and put back the second), but 
from a quick perusal of the code I doubt this will make a material change.

--
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