Re: [PATCH] libata error handling fixes (ATAPI)

Bartlomiej Zolnierkiewicz
2005-11-16T19:11:02Z

On 11/16/05, Jens Axboe <axboe@suse.de> wrote:
> On Wed, Nov 16 2005, Bartlomiej Zolnierkiewicz wrote:
> > On 11/16/05, Jens Axboe <axboe@suse.de> wrote:
> > > On Wed, Nov 16 2005, Bartlomiej Zolnierkiewicz wrote:
> > > > On 11/16/05, Jens Axboe <axboe@suse.de> wrote:
> > > >
> > > > > I updated that patch, and converted IDE and SCSI to use it. See the
> > > > > results here:
> > > > >
> > > > > http://brick.kernel.dk/git/?p=linux-2.6-block.git;a=shortlog;h=blk-softirq
> > > >
> > > > I like it but:
> > > >
> > > > * "we know it's either an FS or PC request" assumption in
> > > > ide_softirq_done() is really wrong
> > >
> > > It used to be correct :-)
> >
> > Sorry but it has been always like that,
> > other requests also pass through ide_end_request()
> > (which of course needs fixing).
>
> You misunderstand, for calls to blk_complete_request() it wasn't true
> initially since it always obyed rq_all_done() (which returns 0 for
> non-fs and non-pc requests).

from blk_complete_request() [ the only user of rq_all_done() ]:

+ /*
+ * for partial completions, fall back to normal end io handling.
+ */
+ if (unlikely(!partial_ok && !rq_all_done(req, nbytes)))
+ if (end_that_request_chunk(req, uptodate, nbytes))
+ return 1;

We still will end up with using ide_softirq_done() for !rq_all_done()
case (non FS/PC request) because majority of them (all?) don't use
partial completions.

Bartlomiej