Merge branch 'abk/run-758-delete-new-pagemap-file' into 'master'

RUN-758: Remove Wasm chunk store file

In case we roll out Wasm chunk store changes and then roll back, this
logic will delete any left over pagemap files. 

See merge request dfinity-lab/public/ic!14668

rs/state_layout/src/state_layout.rs

@@ -226,7 +226,8 @@ struct CheckpointRefData {
 /// │      │       ├── queues.pbuf
 /// │      │       ├── software.wasm
 /// │      │       ├── stable_memory.bin
-/// │      │       └── vmemory_0.bin
+/// │      │       ├── vmemory_0.bin
+/// │      │       └── wasm_chunk_store.bin
 /// │      ├── ingress_history.pbuf
 /// │      ├── split_from.pbuf
 /// │      ├── subnet_queues.pbuf
@@ -1363,6 +1364,10 @@ impl<Permissions: AccessPolicy> CanisterLayout<Permissions> {
     pub fn stable_memory_blob(&self) -> PathBuf {
         self.canister_root.join("stable_memory.bin")
     }
+
+    pub fn wasm_chunk_store(&self) -> PathBuf {
+        self.canister_root.join("wasm_chunk_store.bin")
+    }
 }
 
 fn open_for_write(path: &Path) -> Result<std::fs::File, LayoutError> {

rs/state_manager/src/tip.rs

@@ -482,6 +482,18 @@ fn serialize_canister_to_tip(
             None
         }
     };
+
+    // Remove the wasm_chunk_store file in case we have rolled back after creating it.
+    if canister_layout.wasm_chunk_store().exists() {
+        std::fs::remove_file(canister_layout.wasm_chunk_store()).map_err(|io_err| {
+            CheckpointError::IoError {
+                path: canister_layout.wasm_chunk_store().to_path_buf(),
+                message: "failed to delete existing Wasm chunk store file".to_string(),
+                io_err: io_err.to_string(),
+            }
+        })?;
+    }
+
     // Priority credit must be zero at this point
     assert_eq!(canister_state.scheduler_state.priority_credit.get(), 0);
     canister_layout.canister().serialize(