Merge pull request ceph#64109 from xxhdx1985126/wip-71794

crimson/os/seastore/lba/btree_lba_manager: never downcast reserved ptrs

Reviewed-by: Yingxin Cheng <[email protected]>

Author: cyx1231st

src/crimson/os/seastore/lba/btree_lba_manager.cc

@@ -436,9 +436,13 @@ BtreeLBAManager::insert_mappings(
 	ceph_assert(p.second);
 	iter = std::move(p.first);
 	auto &leaf_node = *iter.get_leaf_node();
+	bool need_reserved_ptr =
+	  info.is_indirect_mapping() || info.is_zero_mapping();
 	leaf_node.insert_child_ptr(
 	  iter.get_leaf_pos(),
-	  info.extent,
+	  need_reserved_ptr
+	    ? get_reserved_ptr<LBALeafNode, laddr_t>()
+	    : static_cast<BaseChildNode<LBALeafNode, laddr_t>*>(info.extent),
 	  leaf_node.get_size() - 1 /*the size before the insert*/);
 	if (is_valid_child_ptr(info.extent)) {
 	  ceph_assert(info.value.pladdr.is_paddr());

src/crimson/os/seastore/lba/btree_lba_manager.h

@@ -286,6 +286,14 @@ class BtreeLBAManager : public LBAManager {
     lba_map_val_t value;
     LogicalChildNode* extent = nullptr;
 
+    bool is_zero_mapping() const {
+      return value.pladdr.is_paddr() && value.pladdr.get_paddr().is_zero();
+    }
+
+    bool is_indirect_mapping() const {
+      return value.pladdr.is_laddr();
+    }
+
     static alloc_mapping_info_t create_zero(extent_len_t len) {
       return {
 	L_ADDR_NULL,
@@ -294,8 +302,7 @@ class BtreeLBAManager : public LBAManager {
 	  pladdr_t(P_ADDR_ZERO),
 	  EXTENT_DEFAULT_REF_COUNT,
 	  0
-	},
-	static_cast<LogicalChildNode*>(get_reserved_ptr<LBALeafNode, laddr_t>())};
+	}};
     }
     static alloc_mapping_info_t create_indirect(
       laddr_t laddr,
@@ -309,8 +316,7 @@ class BtreeLBAManager : public LBAManager {
 	  EXTENT_DEFAULT_REF_COUNT,
 	  0	// crc will only be used and checked with LBA direct mappings
 		// also see pin_to_extent(_by_type)
-	},
-	static_cast<LogicalChildNode*>(get_reserved_ptr<LBALeafNode, laddr_t>())};
+	}};
     }
     static alloc_mapping_info_t create_direct(
       laddr_t laddr,