From: Nikolay Borisov <nborisov@suse.com>
To: Pierre Couderc <pierre@couderc.eu>, linux-btrfs@vger.kernel.org
Subject: Re: Is there some doc or some example of libbtrfs ?
Date: Fri, 7 Aug 2020 13:17:58 +0300 [thread overview]
Message-ID: <4700f999-7914-0453-7096-f2ca360b4be7@suse.com> (raw)
In-Reply-To: <4bf44e81-0b4f-9c99-3010-410e110aec2d@couderc.eu>
On 7.08.20 г. 12:36 ч., Pierre Couderc wrote:
> Ho do I get programmatically the list of the snapshots of a volume in
> C/C++?
>
> I can analyse the output of "btrfs li sh", but is there an easier way ?
>
> I have found no doc or example...
Well, the example is in the source code of btrfs-progs, namely :
btrfs_list_subvols_print
list_subvol_search
TLDR You'd have to use the TREE_SEARCH ioctl which allows you to get
data from btrfs' various trees. In order to figure out what data to pass
to the ioctl you'd have to familiarize yourself with the internal
structure of btrfs trees to know which items represent a snapshot and
which proper subvolumes. You should check the "ROOT ITEM" description at
https://github.com/btrfs/btrfs-dev-docs/blob/master/tree-items.txt to
see when a root item is a snapshot and not a subvolume.
>
> Thanks
>
> PC
>
next prev parent reply other threads:[~2020-08-07 10:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-07 9:36 Is there some doc or some example of libbtrfs ? Pierre Couderc
2020-08-07 10:17 ` Nikolay Borisov [this message]
2020-08-07 10:38 ` Pierre Couderc
2020-08-07 15:20 ` Pierre Couderc
2020-08-10 15:13 ` David Sterba
2020-08-10 16:02 ` Pierre Couderc
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