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Date: Sun, 20 Oct 2013 09:28:35 +0200
From: Bob Marley <bobmarley@shiftmail.org>
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To: Stefan Behrens <sbehrens@giantdisaster.de>
CC: Shilong Wang <wangshilong1991@gmail.com>, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] Btrfs: fix race condition between writting and scrubing
 supers
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On 19/10/2013 16:03, Stefan Behrens wrote:
> On 10/19/2013 12:32, Shilong Wang wrote:
>
> > Yeah, it did not hurt. but it may  output checksum mismatch. For 
> example:
> > Writing 4k superblock is not totally finished, but we are trying to 
> scrub it.
>
> Have you ever seen this issue?
>

...

> If this is really an issue and these 4K disk writes and reads 
> interfere, let's find a better solution please.
>


Why don't you scrub optimistically as is now, and then just in case of 
checksum mismatch you re-scrub in transaction context?