Re: Device loses barrier support (was: Fixed patch for simple barriers.)
From: Andi Kleen
Date: Thu Dec 04 2008 - 09:09:23 EST
> the 1st write request ends with success
> the 2nd write request ends with -EOPNOTSUPP
> the 3rd write request ends with success
>
> --- when you first see -EOPNOTSUPP, you have already corrupted filesystem
> (the 3rd write passed while the filesystem expected that it would be
There's no passing of requests during pvmove. It's a really strong
barrier.
> finished after the 2nd write) and you are in an interrupt context, where
> you can't reissue -EOPNOTSUPP request. So what do you want to do?
The barrier aware file systems I know of just resubmit synchronously when
a barrier fails.
-Andi
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