Fix paritytech#2407

tomaka · Jun 21, 2022 · 7731e0b · 7731e0b
1 parent 80dc1fb
commit 7731e0b
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Showing 3 changed files with 26 additions and 3 deletions.
diff --git a/bin/light-base/src/sync_service/parachain.rs b/bin/light-base/src/sync_service/parachain.rs
@@ -208,9 +208,14 @@ pub(super) async fn start_parachain<TPlat: Platform>(
                             // TODO: what about an `else`? does sync_sources leak if the block can't be decoded?
                         }
 
-                        // Must unpin the pruned blocks if they haven't already been unpinned.
-                        for (_, hash, pruned_block_parahead) in pruned_blocks {
-                            if pruned_block_parahead.is_none() {
+                        // Must unpin the pruned blocks if they haven't already been unpinned and
+                        // if there is no operation in progress. In case where there is a parahead
+                        // fetch operation in progress for this block, the operation uses the pin
+                        // and block will be unpinned when the operation is finished.
+                        for (block_index, _, pruned_block_parahead) in pruned_blocks {
+                            if pruned_block_parahead.is_none()
+                                && async_tree.block_async_op_in_progress(block_index).is_none()
+                            {
                                 relay_chain_subscribe_all
                                     .new_blocks
                                     .unpin_block(&hash)

diff --git a/bin/wasm-node/CHANGELOG.md b/bin/wasm-node/CHANGELOG.md
@@ -10,6 +10,7 @@
 
 - Fix errors about verifying justifications. Justifications and Grandpa commits that can't be verified yet are now properly stored in memory in order to be verified later, instead of producing errors. ([#2400](https://github.com/paritytech/smoldot/pull/2400))
 - Fix issue where unverified justifications would overwrite one another, meaning that an invalid justification could potentially prevent a valid justification from being taken into account. ([#2400](https://github.com/paritytech/smoldot/pull/2400))
+- Fix panic when a relay chain block is pruned at the same time as we are trying to determine the parachain block corresponding to it.
 
 ## 0.6.19 - 2022-06-14
 

diff --git a/src/chain/async_tree.rs b/src/chain/async_tree.rs
@@ -324,6 +324,23 @@ where
         }
     }
 
+    /// If an asynchronous operation is in progress and targets the given block, returns the
+    /// identifier of this asynchronous operation.
+    ///
+    /// Returns `None` if the asynchronous operation of this block is either already finished or
+    /// not started yet.
+    ///
+    /// # Panic
+    ///
+    /// Panics if the [`NodeIndex`] is invalid.
+    ///
+    pub fn block_async_op_in_progress(&self, node_index: NodeIndex) -> Option<AsyncOpId> {
+        match &self.non_finalized_blocks.get(node_index).unwrap().async_op {
+            AsyncOpState::InProgress { async_op_id, .. } => Some(*async_op_id),
+            _ => None,
+        }
+    }
+
     /// Returns the parent of the given node. Returns `None` if the node doesn't have any parent,
     /// meaning that its parent is the finalized node.
     ///