crimson/os/seastore/FixedKVBtree: return BtreeCursor instead of BtreeMapping

Signed-off-by: Zhang Song <[email protected]>
(cherry picked from commit 84cb3d8)

Author: zhscn

src/crimson/os/seastore/backref/btree_backref_manager.h

@@ -31,7 +31,7 @@ constexpr size_t BACKREF_BLOCK_SIZE = 4096;
 
 using BackrefBtree = FixedKVBtree<
   paddr_t, backref_map_val_t, BackrefInternalNode,
-  BackrefLeafNode, BtreeBackrefMapping, BACKREF_BLOCK_SIZE>;
+  BackrefLeafNode, BackrefCursor, BACKREF_BLOCK_SIZE>;
 
 class BtreeBackrefManager : public BackrefManager {
 public:

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

@@ -37,7 +37,7 @@ template <
   typename node_val_t,
   typename internal_node_t,
   typename leaf_node_t,
-  typename pin_t,
+  typename cursor_t,
   size_t node_size>
 class FixedKVBtree {
   static constexpr size_t MAX_DEPTH = 16;
@@ -46,7 +46,7 @@ class FixedKVBtree {
     node_val_t,
     internal_node_t,
     leaf_node_t,
-    pin_t,
+    cursor_t,
     node_size>;
 public:
   using InternalNodeRef = TCachedExtentRef<internal_node_t>;
@@ -201,22 +201,15 @@ class FixedKVBtree {
       return leaf.pos == 0;
     }
 
-    std::unique_ptr<pin_t> get_pin(op_context_t ctx) const {
+    std::unique_ptr<cursor_t> get_cursor(op_context_t ctx) const {
       assert(!is_end());
-      auto val = get_val();
-      auto key = get_key();
-      node_key_t end{};
-      if constexpr (std::is_same_v<node_key_t, laddr_t>) {
-        end = (key + val.len).checked_to_laddr();
-      } else {
-        end = key + val.len;
-      }
-      return std::make_unique<pin_t>(
+      return std::make_unique<cursor_t>(
         ctx,
 	leaf.node,
-        leaf.pos,
-	val,
-	fixed_kv_node_meta_t<node_key_t>{ key, end, 0 });
+        leaf.node->modifications,
+        get_key(),
+        std::make_optional(get_val()),
+        leaf.pos);
     }
 
     typename leaf_node_t::Ref get_leaf_node() {
@@ -2144,15 +2137,15 @@ template <
   typename node_val_t,
   typename internal_node_t,
   typename leaf_node_t,
-  typename pin_t,
+  typename cursor_t,
   size_t node_size>
 struct is_fixed_kv_tree<
   FixedKVBtree<
     node_key_t,
     node_val_t,
     internal_node_t,
     leaf_node_t,
-    pin_t,
+    cursor_t,
     node_size>> : std::true_type {};
 
 template <

src/crimson/os/seastore/lba_manager/btree/btree_lba_manager.cc

@@ -483,7 +483,7 @@ _init_cached_extent(
 	  iter.get_val().pladdr.get_paddr() == logn->get_paddr()) {
 	assert(!iter.get_leaf_node()->is_pending());
 	iter.get_leaf_node()->link_child(logn.get(), iter.get_leaf_pos());
-	logn->set_laddr(iter.get_pin(c)->get_key());
+	logn->set_laddr(iter.get_key());
 	ceph_assert(iter.get_val().len == e->get_length());
 	DEBUGT("logical extent {} live", c.trans, *logn);
 	ret = true;

src/crimson/os/seastore/lba_manager/btree/btree_lba_manager.h

@@ -231,7 +231,7 @@ using BtreeLBAMappingRef = std::unique_ptr<BtreeLBAMapping>;
 
 using LBABtree = FixedKVBtree<
   laddr_t, lba_map_val_t, LBAInternalNode,
-  LBALeafNode, BtreeLBAMapping, LBA_BLOCK_SIZE>;
+  LBALeafNode, LBACursor, LBA_BLOCK_SIZE>;
 
 /**
  * BtreeLBAManager