[elbe-devel] [PATCH v3 0/3] Add support for nested btrfs subvolume hierarchies

[Bastian Germann]

Hi Daniel,

Am 25.11.22 um 19:17 schrieb Daniel Braunwarth:
> Btrfs supports three subvolume hierarchies: flat, nested and mixed. Detailed
> explanations of each can be found at the btrfs SysadminGuide:
> 
> https://btrfs.wiki.kernel.org/index.php/SysadminGuide#Layout
> 
> This series of patches adds support for nested btrfs subvolume hierarchies. I'm
> planning to add support for flat and mixed hierarchies in a second step.
> 
> With this patches applied the following subvolume hierarchy can be easily
> achieved:
> 
> toplevel                  (volume root directory, to be mounted at /)
> +-- home                  (subvolume root directory)
> +-- var                   (subvolume root directory)
>      +-- www               (subvolume root directory)
>      +-- lib               (directory)
>           \-- postgresql   (subvolume root directory)

Thanks for posting this series. I would like to cater to your need, however, introducing such shenanigans for each 
filesystem is a bit out of scope. There is already tune2fs which modifies an ext filesystem.

If you want volume support for btrfs please abstract it in a way that one can run filesystem modifications via 
specifying a command template like commands in finetuning. Please convert the tune2fs code to use this abstraction 
instead by introducing an XML preprocess rule for it.

Thanks,
Bastian