Re: DM-RAID1 data corruption

[Takahiro Yasui <tyasui@redhat.com>]

malahal@us.ibm.com wrote:
> Look at this patch
> http://permalink.gmane.org/gmane.linux.kernel.device-mapper.devel/4973
>
> It essentially generates an uevet and waits for the user level code to
> act on it and send a message to unblock it.

This patch was posted more then a year ago, and I could not find
any discussion on this issue/patch in the mailing list archive.
What was the conclusion of the discussion about this patch?
Are there any discussions outside this mailing list?

I think data corruption is really a serious problem even if it
has very small chance to happen. If it is a known problem, we
need to fix it. Don't you agree?

I roughly looked your patch, and I understand it is one of the
approach to fix this issue. I have just one concern about delay.
When 'unblock' message is delayed for some reason (by dmeventd?),
all write I/Os from applications need to be waited, and many I/Os
might come in a write queue and be blocked during 'block' status.

Thanks,
Taka