This commit provides an API to obtain an information about
snapshot and clone relations.
The main objective is:
1) Determinate if we can delete snapshot (if have some created
clones),
2) Provide an information about parent/children nodes to the upper
layer (e.g. lvol)
Realization:
1) Structure parent-children is stored in the blob store object
and updated on:
a) blob store load,
b) blob create/delete,
2) Full information about parent-children is provided via new API:
spdk_blob_get_parent() and spdk_blob_get_children(),
Note:
While we don't store an information about these relations in the
blob store, we need to open all blobs on blob store load to create
it. It should be considered that it have an impact on the blobstore
loading performance.
Change-Id: Ie0237fa5b93af01aa73d1f68ac1694e653fb75e5
Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>
Reviewed-on: https://review.gerrithub.io/405025
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Maciej Szwed <maciej.szwed@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>