Mount Point Name Support

The Shared File Systems service supports user defined mount point names. This feature allows users to specify a custom mount_point_name during share creation, which will be reflected in the share’s export location. However, for this feature to be available to users, administrators must enable an extra-spec in the share type, mount_point_name_support, and set an extra-spec named provisioning:mount_point_prefix.

If the provisioning:mount_point_prefix extra-spec is not set, the project_id from the RequestContext is used as a fallback. However, using the project_id as a prefix can restrict the transfer of share ownership, and manual action required to facilitate the transfer.

Note

  • In order to use this feature, the available backend in your deployment must have support for it. The list of backends that support this feature in the manila can be found in the Manila share features support mapping.

  • This feature is only available in API version 2.84 and beyond.

  • The extra-spec type mount_point_name_support required for this feature to work.

  • When the project_id is used as a prefix due to the absence of the provisioning:mount_point_prefix extra-spec, the transfer of share ownership may be restricted, and manual action may be required.

Administrator Guide

  1. Configuring `mount_point_name_support` and `provisioning:mount_point_prefix`

    openstack share type set <share_type> --extra-spec \
mount_point_name_support="<is> True"
provisioning:mount_point_prefix=<prefix>

    Replace <share_type> with the name of the share type you are configuring, and <prefix> with the desired prefix. The <prefix> should be a string containing ASCII alphabets and optionally, the underscore character.

  2. Default Behavior and Security Considerations

    If provisioning:mount_point_prefix is not set, the system will use the project_id as the default prefix for the mount_point_name. However, be aware that setting provisioning:mount_point_prefix to a constant string and sharing the share type with multiple projects could potentially leak information about the existence of other shares. This could be considered a security hole and should be avoided.

  3. Share Transfer

    During a share transfer, if provisioning:mount_point_prefix contains a project_id, the system will refuse to perform the transfer and return an HTTP 400 error. This indicates that the share has some project identity that requires administrator intervention. To perform the transfer, administrators will need to unmanage the share from the current project and manage it into the target project.

  4. Constructing `mount_point_name`

    The mount_point_name is constructed by combining the prefix from the share type (set by provisioning:mount_point_prefix) and the suffix provided by the user. This combined string must be ASCII alphanumeric, allowing only underscores as special characters. If this validation fails, the system will log an error and return a message indicating that the mount_point_name is not appropriate.