rbd: getRBDSnapID and ProcessMetadata issues in snapshot metadata path

[kaovilai]

Problem

Several issues exist in the RBD snapshot metadata code path (ProcessMetadata / getRBDSnapID) that would cause incorrect behavior for certain snapshot configurations:

1. getRBDSnapID uses GetParent() which fails for non-clone snapshots

GetParent() only works for clone-based snapshots with a parent relationship. For regular RBD snapshots or flattened clones, GetParent() returns ErrNotFound. Should use GetSnapshotNames() which reliably lists all snapshots on the image regardless of clone/parent relationships.

2. SnapInfo field name mismatch: Id vs ID

The go-ceph SnapInfo struct uses the field name Id, not ID.

3. ProcessMetadata opens wrong image

ProcessMetadata opens the source volume via rbdSnap.open() (which uses RbdImageName = source volume name), but getRBDSnapID() returns the snapshot ID from the clone image (via toVolume()). This mismatch means SetSnapByID() applies a clone's snapshot ID to the source volume, resulting in either an error or iterating over wrong/empty data.

Context

These issues were discovered during investigation of empty GetMetadataAllocated streams. While the original symptom turned out to be a test-side device path mismatch (details), the code issues identified above are real bugs that should be fixed.

Note

Responses generated with Claude