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From: Nikolay Borisov <nborisov@suse.com>
To: linux-btrfs@vger.kernel.org
Subject: Re: how do I know a subvolume is a snapshot?
Date: Wed, 17 Jul 2019 11:24:51 +0300	[thread overview]
Message-ID: <eff513b1-a77c-cd5f-5af7-87eae73cff6a@suse.com> (raw)
In-Reply-To: <20190716232456.GA26411@tik.uni-stuttgart.de>



On 17.07.19 г. 2:24 ч., Ulli Horlacher wrote:
> I thought, I can recognize a snapshot when it has a Parent UUID, but this
> is not true for snapshots of toplevel subvolumes: 

As you have asked this before - in my testing this is not true. Looking
at the code it also seems snapshots get a parent. Alternatively you have
to parse the root tree - the ROOT_ITEM's offset member should be 0 for
well-known trees/ordinary subvolume or the transaction id when the
snapshot was created.

  parent reply	other threads:[~2019-07-17  8:25 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-16 23:24 how do I know a subvolume is a snapshot? Ulli Horlacher
2019-07-17  7:45 ` Bernhard Kühnel
2019-07-17  8:05   ` Ulli Horlacher
2019-07-17 10:33   ` Remi Gauvin
2019-07-17  8:23 ` Hans van Kranenburg
2019-07-17  8:57   ` misono.tomohiro
2019-07-17  9:06     ` Ulli Horlacher
2019-07-17  9:24       ` misono.tomohiro
2019-07-17  8:24 ` Nikolay Borisov [this message]
2019-07-17  9:11   ` Ulli Horlacher
2019-07-17 10:11     ` Nikolay Borisov
2019-07-17 10:29       ` Andrei Borzenkov
2019-07-17 11:19         ` Nikolay Borisov
2019-07-17 17:39           ` Andrei Borzenkov
2019-07-17 18:16             ` Nikolay Borisov

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