Comment 1 for bug 2033883

Would the existing raw_volume interface [1] be sufficient? It grants r/w permissions to a particular specified partition, as well as r/x access for the mkfs binary to format that partition if necessary [2].

[1]: https://forum.snapcraft.io/t/the-raw-volume-interface/14578
[2]: https://github.com/snapcore/snapd/blob/master/interfaces/builtin/raw_volume.go#L52-L67