For btrfs driver, in d.Create(), Get() of parentDir is called but not followed
by Put().
If we apply SElinux mount label, we need to mount btrfs subvolumes in d.Get(),
without a Put() would end up with a later Remove() failure on
"Device resourse is busy".
This calls the subvolume helper function directly in d.Create().
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Upstream-commit: b2e27fee53c269f9659bdab66852eaba4ffbe9c7
Component: engine
f06d92067d