bolt k/v pairs are only valid for the life of a transaction.
This means the memory that the k/v pair is referencing may be invalid if
it is accessed outside of the transaction.
This can potentially cause a panic.
For reference: https://godoc.org/github.com/boltdb/bolt#hdr-Caveats
To fix this issue, unmarshal the stored data into volume meta before
closing the transaction.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Ensures all known volumes (known b/c they are persisted to disk) have
their volume drivers refcounted properly.
In testing this, I found an issue with `--live-restore` (required since
currently the provided volume plugin doesn't keep state on restart)
where restorted plugins did not have a plugin client loaded causing a
panic when trying to use the plugin.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
