crimson/os/seastore/linked_tree_node: rename

`BaseChildNode::get_parent_node()` to
`BaseChildNode::peek_parent_node()`

Signed-off-by: Xuehan Xu <[email protected]>

Author: xxhdx1985126

src/crimson/os/seastore/btree/fixed_kv_btree.h

@@ -496,12 +496,12 @@ class FixedKVBtree {
           assert(cnode->has_parent_tracker());
           if (node->is_pending()) {
             auto &n = node->get_stable_for_key(i->get_key());
-            assert(cnode->get_parent_node().get() == &n);
+            assert(cnode->peek_parent_node().get() == &n);
             auto pos = n.lower_bound(i->get_key()).get_offset();
             assert(pos < n.get_size());
             assert(n.children[pos] == cnode.get());
           } else {
-            assert(cnode->get_parent_node().get() == node.get());
+            assert(cnode->peek_parent_node().get() == node.get());
             assert(node->children[i->get_offset()] == cnode.get());
           }
         } else if (child_node->is_pending()) {
@@ -511,12 +511,12 @@ class FixedKVBtree {
             assert(prior.is_parent_valid());
             if (node->is_mutation_pending()) {
               auto &n = node->get_stable_for_key(i->get_key());
-              assert(prior.get_parent_node().get() == &n);
+              assert(prior.peek_parent_node().get() == &n);
               auto pos = n.lower_bound(i->get_key()).get_offset();
               assert(pos < n.get_size());
               assert(n.children[pos] == &prior);
             } else {
-              assert(prior.get_parent_node().get() == node.get());
+              assert(prior.peek_parent_node().get() == node.get());
               assert(node->children[i->get_offset()] == &prior);
             }
           } else {
@@ -567,9 +567,9 @@ class FixedKVBtree {
         } else {
           auto c = static_cast<child_node_t*>(child);
           assert(c->has_parent_tracker());
-          assert(c->get_parent_node().get() == node.get()
+          assert(c->peek_parent_node().get() == node.get()
             || (node->is_pending() && c->is_stable()
-                && c->get_parent_node().get() == &node->get_stable_for_key(
+                && c->peek_parent_node().get() == &node->get_stable_for_key(
                   i->get_key())));
         }
       } else {

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

@@ -1091,7 +1091,7 @@ BtreeLBAManager::_update_mapping(
 	    }
 	    assert(!nextent || 
 	           (nextent->has_parent_tracker() &&
-		    nextent->get_parent_node().get() == iter.get_leaf_node().get()));
+		    nextent->peek_parent_node().get() == iter.get_leaf_node().get()));
 	    return update_mapping_ret_bare_t(iter.get_cursor(c));
 	  });
 	}

src/crimson/os/seastore/linked_tree_node.h

@@ -196,7 +196,10 @@ class BaseChildNode {
   bool is_parent_valid() const {
     return parent_tracker && parent_tracker->is_valid();
   }
-  TCachedExtentRef<ParentT> get_parent_node() const {
+  // this method should only be used for asserts and logs, because
+  // the parent node might be stable writing and should "wait_io"
+  // before further access
+  TCachedExtentRef<ParentT> peek_parent_node() const {
     assert(parent_tracker);
     return parent_tracker->get_parent();
   }
@@ -999,7 +1002,7 @@ class ChildNode : public BaseChildNode<ParentT, key_t> {
     assert(!down_cast().is_btree_root());
     assert(this->has_parent_tracker());
     auto off = get_parent_pos();
-    auto parent = this->get_parent_node();
+    auto parent = this->peek_parent_node();
     assert(parent->children[off] == &down_cast());
     parent->children[off] = nullptr;
   }
@@ -1018,15 +1021,15 @@ class ChildNode : public BaseChildNode<ParentT, key_t> {
     this->parent_tracker = prior.BaseChildNode<ParentT, key_t>::parent_tracker;
     assert(this->has_parent_tracker());
     auto off = get_parent_pos();
-    auto parent = this->get_parent_node();
+    auto parent = this->peek_parent_node();
     assert(me.get_prior_instance().get() ==
 	   dynamic_cast<CachedExtent*>(parent->children[off]));
     parent->children[off] = &me;
   }
 
   btreenode_pos_t get_parent_pos() const {
     auto &me = down_cast();
-    auto parent = this->get_parent_node();
+    auto parent = this->peek_parent_node();
     assert(parent);
     //TODO: can this search be avoided?
     auto key = me.get_begin();

src/crimson/os/seastore/omap_manager/btree/omap_btree_node_impl.cc

@@ -596,7 +596,7 @@ std::ostream &OMapLeafNode::print_detail_l(std::ostream &out) const
 	<< ", end=" << get_end();
   }
   if (this->child_node_t::is_parent_valid())
-    return out << ", parent=" << (void*)this->child_node_t::get_parent_node().get();
+    return out << ", parent=" << (void*)this->child_node_t::peek_parent_node().get();
   else
     return out;
 }