[storage/journal] prevent read-blocking during contiguous journal prune

runtime/src/lib.rs

@@ -705,6 +705,8 @@ stability_scope!(BETA {
         /// Remove a blob from a given partition.
         ///
         /// If no `name` is provided, the entire partition is removed.
+        /// If a `name` is provided, existing [Blob] handles for that blob must remain readable
+        /// until they are dropped, but the blob must be removed from future namespace lookups.
         ///
         /// An Ok result indicates the blob is durably removed.
         fn remove(

runtime/src/storage/mod.rs

@@ -305,6 +305,7 @@ pub(crate) mod tests {
         test_read_at_buf_returns_same_buffer(&storage).await;
         test_read_at_buf_insufficient_capacity(&storage).await;
         test_read_at_buf_larger_capacity(&storage).await;
+        test_read_after_remove(&storage).await;
     }
 
     /// Test opening a blob, writing to it, and reading back the data.
@@ -342,6 +343,25 @@ pub(crate) mod tests {
         assert!(blobs.is_empty(), "Blob was not removed as expected");
     }
 
+    /// Test that existing blob handles remain readable after the blob is removed from storage.
+    async fn test_read_after_remove<S>(storage: &S)
+    where
+        S: Storage + Send + Sync,
+        S::Blob: Send + Sync,
+    {
+        let (blob, _) = storage.open("read_after_remove", b"blob").await.unwrap();
+        blob.write_at(0, b"still here").await.unwrap();
+        blob.sync().await.unwrap();
+
+        storage
+            .remove("read_after_remove", Some(b"blob"))
+            .await
+            .unwrap();
+
+        let read = blob.read_at(0, 10).await.unwrap();
+        assert_eq!(read.coalesce(), b"still here");
+    }
+
     /// Test scanning a partition for blobs.
     async fn test_scan<S>(storage: &S)
     where

storage/Cargo.toml

@@ -38,6 +38,7 @@ commonware-math.workspace = true
 commonware-runtime = { workspace = true, features = ["test-utils"] }
 commonware-storage = { path = ".", features = ["std"] }
 criterion.workspace = true
+governor.workspace = true
 rand.workspace = true
 rstest.workspace = true
 tracing-subscriber.workspace = true