refactor: Move manifest manager lock to MitoRegion (#3689)

* feat: remove manager inner wip

* feat: put manifest lock in region

* feat: don't update manifest if manager is stopped

* chore: address CR comments

src/mito2/src/engine/catchup_test.rs

@@ -345,7 +345,7 @@ async fn test_catchup_with_manifest_update() {
     // Ensures the mutable is empty.
     assert!(region.version().memtables.mutable.is_empty());
 
-    let manifest = region.manifest_manager.manifest().await;
+    let manifest = region.manifest_manager.read().await.manifest();
     assert_eq!(manifest.manifest_version, 0);
 
     let resp = follower_engine
@@ -361,7 +361,7 @@ async fn test_catchup_with_manifest_update() {
 
     // The inner region was replaced. We must get it again.
     let region = follower_engine.get_region(region_id).unwrap();
-    let manifest = region.manifest_manager.manifest().await;
+    let manifest = region.manifest_manager.read().await.manifest();
     assert_eq!(manifest.manifest_version, 2);
     assert!(!region.is_writable());
 

src/mito2/src/error.rs

@@ -578,6 +578,12 @@ pub enum Error {
 
     #[snafu(display("checksum mismatch (actual: {}, expected: {})", actual, expected))]
     ChecksumMismatch { actual: u32, expected: u32 },
+
+    #[snafu(display("Region {} is stopped", region_id))]
+    RegionStopped {
+        region_id: RegionId,
+        location: Location,
+    },
 }
 
 pub type Result<T, E = Error> = std::result::Result<T, E>;
@@ -684,6 +690,7 @@ impl ErrorExt for Error {
             BiError { .. } => StatusCode::Internal,
             EncodeMemtable { .. } | ReadDataPart { .. } => StatusCode::Internal,
             ChecksumMismatch { .. } => StatusCode::Unexpected,
+            RegionStopped { .. } => StatusCode::RegionNotReady,
         }
     }