this is a workaround for the unmount device issue caused by gci mounter. In GCI cluster, if gci mounter is used for mounting, the container started by mounter script will cause additional mounts created in the container. Since these mounts are irrelavant to the original mounts, they should be not considered when checking the mount references. By comparing the mount path prefix, those additional mounts can be filtered out.
Plan to work on better approach to solve this issue.
Don't store Gluster SotrageClass parameters in annotations, it's insecure.
Instead, expect that there is the StorageClass available at the time
when it's needed by Gluster deleter.
This change is for fixing PR #30930. The function should check if the
mountpath is still mounted or not. If it is not, it should continue with
removing the directory instead of returning error.
