[dm-devel] Re: [RFC][PATCH] dm-mirror: fix data corruption

[Mikulas Patocka]

On Sun, 30 Aug 2009, malahal at us.ibm.com wrote:

> Mikulas Patocka [mpatocka at redhat.com] wrote:
> > 
> > > How do bios queued in ms->failures are processed later? It seems that
> > > the bios stay in ms->failures forever, and the upper layer can not
> > > receive "success" for those bios. Don't we need a mechanism to block/unblock
> > > write bios to fix this issue?
> > 
> > They are resubmitted with DM_ENDIO_REQUEUE on noflush suspend. My patch 
> > has a bug that they aren't --- but I will provide a better patch, also 
> > without this periodic polling of ms->failures queue.
> 
> Trying to verify this patch. Mikulas, did you provide a better patch
> yet? Does this patch work at all?
> 
> I would like to verify if this patch works with devices that fail
> temporarily. I will plan on using dm-flakey devices for testing purposes.
> 
> Thanks, Malahal.

Hi

I uploaded patches for this bug at: 
http://people.redhat.com/mpatocka/patches/kernel/mirror-race/

But note! They were never tried. When I wanted to try them, I found out 
that dmeventd is totally nonworking in upstream code (it doesn't pass 
"handle_errors" argument and has some crashes and signal errors), so I 
didn't test them with dmeventd. Dmeventd must be fixed first, then we can 
work on this bug.

Mikulas