librbd: Add snapshot namespace to snapshot-name index in ImageCtx

The essence of this huge change is to have two keys for indexing
snap ids in ImageCtx. It used to be a map of (snap_name -> snap_id)
now it's (snap_namespace, snap_name) -> snap_id. Therefore now snapshots
can have the same name if they are in different namespaces.
All the remaining changes are a consequece of this change of
ImageCtx.snap_ids field. The only exception is: we assume that you can't
rename snapshots from GroupSnapshotNamespaces. So rename operation
always assumes UserSnapshotNamespace.

Signed-off-by: Victor Denisov <denisovenator@gmail.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/librbd/operation/SnapshotRollbackRequest.h b/src/librbd/operation/SnapshotRollbackRequest.h
index 5d1cb69e85c..a32a84dc27b 100644
--- a/src/librbd/operation/SnapshotRollbackRequest.h
+++ b/src/librbd/operation/SnapshotRollbackRequest.h
@@ -57,7 +57,9 @@ public:
    */
 
   SnapshotRollbackRequest(ImageCtxT &image_ctx, Context *on_finish,
-                          const std::string &snap_name, uint64_t snap_id,
+			  const cls::rbd::SnapshotNamespace &snap_namespace,
+                          const std::string &snap_name,
+			  uint64_t snap_id,
                           uint64_t snap_size, ProgressContext &prog_ctx);
   ~SnapshotRollbackRequest() override;
 
@@ -68,10 +70,11 @@ protected:
   }
 
   journal::Event create_event(uint64_t op_tid) const override {
-    return journal::SnapRollbackEvent(op_tid, m_snap_name);
+    return journal::SnapRollbackEvent(op_tid, m_snap_namespace, m_snap_name);
   }
 
 private:
+  cls::rbd::SnapshotNamespace m_snap_namespace;
   std::string m_snap_name;
   uint64_t m_snap_id;
   uint64_t m_snap_size;