Our write pattern is quite awful for CoW file systems (btrfs...), as we
keep updating file parts in the beginning of the file. This results in
fragmented journal files. Hence: when rotating files, defragment them,
since at that point we know that no further write accesses will be made.
This adds a new bus call to machined that enumerates /var/lib/container
and returns all trees stored in it, distuingishing three types:
- GPT disk images, which are files suffixed with ".gpt"
- directory trees
- btrfs subvolumes
Zbigniew Jędrzejewski-Szmek