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Subject: Re: [RFC] Improve subvolume usability for a normal user
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
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From: Marat Khalili <mkh@rqc.ru>
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Date: Thu, 7 Dec 2017 10:32:21 +0300
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On 07/12/17 08:27, Qu Wenruo wrote:
> When doing snapshot, btrfs only needs to increase reference of 2nd
> highest level tree blocks of original snapshot, other than "walking the
> tree".
> (If tree root level is 2, then level 2 node is copied, while all
> reference of level 1 tree blocks get increased)

Out of curiosity, how does it interacts with nocow files? Does every 
write to these files involves backref walk?

--

With Best Regards,
Marat Khalili