crimson/os/seastore: refactor LBAMapping and BackrefMapping

Signed-off-by: Zhang Song <[email protected]>
(cherry picked from commit 23883c9)

Author: zhscn

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

@@ -9,24 +9,6 @@
 
 namespace crimson::os::seastore::backref {
 
-class BtreeBackrefMapping : public BackrefMapping {
-public:
-  BtreeBackrefMapping(
-    op_context_t ctx,
-    BackrefLeafNodeRef parent,
-    uint16_t pos,
-    backref_map_val_t &val,
-    backref_node_meta_t &&meta)
-    : BackrefMapping(
-	val.type,
-	ctx,
-	parent,
-	pos,
-	val.laddr,
-	val.len,
-	std::forward<backref_node_meta_t>(meta)) {}
-};
-
 constexpr size_t BACKREF_BLOCK_SIZE = 4096;
 
 using BackrefBtree = FixedKVBtree<

src/crimson/os/seastore/backref_mapping.h

@@ -8,50 +8,52 @@
 namespace crimson::os::seastore {
 
 class BackrefMapping {
-  op_context_t ctx;
-  CachedExtentRef parent;
-  fixed_kv_node_meta_t<paddr_t> range;
-  laddr_t value;
-  extent_len_t len = 0;
-  uint16_t pos = std::numeric_limits<uint16_t>::max();
-  extent_types_t type;
+  BackrefCursorRef cursor;
+
+  BackrefMapping(BackrefCursorRef cursor)
+      : cursor(std::move(cursor)) {}
+
 public:
-  BackrefMapping(
-    extent_types_t type,
-    op_context_t ctx,
-    CachedExtentRef parent,
-    uint16_t pos,
-    laddr_t value,
-    extent_len_t len,
-    fixed_kv_node_meta_t<paddr_t> meta)
-      : ctx(ctx),
-	parent(parent),
-	range(meta),
-	value(value),
-	len(len),
-	pos(pos),
-	type(type)
-  {}
+  static BackrefMapping create(BackrefCursorRef cursor) {
+    return BackrefMapping(std::move(cursor));
+  }
+
+  BackrefMapping() = default;
+
+  BackrefMapping(const BackrefMapping &) = delete;
+  BackrefMapping(BackrefMapping &&) = default;
+
+  BackrefMapping &operator=(const BackrefMapping &) = delete;
+  BackrefMapping &operator=(BackrefMapping &&) = default;
+
+  ~BackrefMapping() = default;
+
+  bool is_viewable() const {
+    assert(cursor);
+    return cursor->is_viewable();
+  }
 
   extent_len_t get_length() const {
-    ceph_assert(range.end > range.begin);
-    return len;
+    assert(cursor);
+    return cursor->get_length();
   }
 
   laddr_t get_val() const {
-    return value;
+    assert(cursor);
+    return cursor->get_laddr();
   }
 
   paddr_t get_key() const {
-    return range.begin;
+    assert(cursor);
+    return cursor->get_paddr();
   }
 
   extent_types_t get_type() const {
-    return type;
+    assert(cursor);
+    return cursor->get_type();
   }
 };
 
-using BackrefMappingRef = std::unique_ptr<BackrefMapping>;
-using backref_pin_list_t = std::list<BackrefMappingRef>;
+using backref_mapping_list_t = std::list<BackrefMapping>;
 
 } // namespace crimson::os::seastore

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

@@ -89,37 +89,6 @@ template class TreeRootLinker<RootBlock, lba_manager::btree::LBALeafNode>;
 
 namespace crimson::os::seastore::lba_manager::btree {
 
-get_child_ret_t<lba_manager::btree::LBALeafNode, LogicalChildNode>
-BtreeLBAMapping::get_logical_extent(Transaction &t)
-{
-  ceph_assert(is_parent_viewable());
-  assert(pos != std::numeric_limits<uint16_t>::max());
-  ceph_assert(t.get_trans_id() == ctx.trans.get_trans_id());
-  auto &p = static_cast<LBALeafNode&>(*parent);
-  auto k = this->is_indirect()
-    ? this->get_intermediate_base()
-    : get_key();
-  return p.template get_child<LogicalChildNode>(ctx.trans, ctx.cache, pos, k);
-}
-
-bool BtreeLBAMapping::is_stable() const
-{
-  assert(!parent_modified());
-  assert(pos != std::numeric_limits<uint16_t>::max());
-  auto &p = (LBALeafNode&)*parent;
-  auto k = is_indirect() ? get_intermediate_base() : get_key();
-  return p.is_child_stable(ctx, pos, k);
-}
-
-bool BtreeLBAMapping::is_data_stable() const
-{
-  assert(!parent_modified());
-  assert(pos != std::numeric_limits<uint16_t>::max());
-  auto &p = (LBALeafNode&)*parent;
-  auto k = is_indirect() ? get_intermediate_base() : get_key();
-  return p.is_child_data_stable(ctx, pos, k);
-}
-
 BtreeLBAManager::mkfs_ret
 BtreeLBAManager::mkfs(
   Transaction &t)

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

@@ -29,206 +29,6 @@ class LogicalCachedExtent;
 
 namespace crimson::os::seastore::lba_manager::btree {
 
-class BtreeLBAMapping : public LBAMapping {
-// To support cloning, there are two kinds of lba mappings:
-// 	1. physical lba mapping: the pladdr in the value of which is the paddr of
-// 	   the corresponding extent;
-// 	2. indirect lba mapping: the pladdr in the value of which is an laddr pointing
-// 	   to the physical lba mapping that's pointing to the actual paddr of the
-// 	   extent being searched;
-//
-// Accordingly, BtreeLBAMapping may also work under two modes: indirect or direct
-// 	1. BtreeLBAMappings that come from quering an indirect lba mapping in the lba tree
-// 	   are indirect;
-// 	2. BtreeLBAMappings that come from quering a physical lba mapping in the lba tree
-// 	   are direct.
-//
-// For direct BtreeLBAMappings, there are two important fields:
-//      1. key: the laddr of the lba mapping being queried;
-//      2. paddr: the paddr recorded in the value of the lba mapping being queried.
-// For indirect BtreeLBAMappings, BtreeLBAMapping has three important fields:
-// 	1. key: the laddr key of the lba entry being queried;
-// 	2. intermediate_key: the laddr within the scope of the physical lba mapping
-// 	   that the current indirect lba mapping points to; although an indirect mapping
-// 	   points to the start of the physical lba mapping, it may change to other
-// 	   laddr after remap
-// 	3. intermediate_base: the laddr key of the physical lba mapping, intermediate_key
-// 	   and intermediate_base should be the same when doing cloning
-// 	4. intermediate_offset: intermediate_key - intermediate_base
-// 	5. intermediate_length: the length of the actual physical lba mapping
-// 	6. paddr: the paddr recorded in the physical lba mapping pointed to by the
-// 	   indirect lba mapping being queried;
-//
-// NOTE THAT, for direct BtreeLBAMappings, their intermediate_keys are the same as
-// their keys.
-public:
-  BtreeLBAMapping(op_context_t ctx)
-    : LBAMapping(ctx) {}
-  BtreeLBAMapping(
-    op_context_t c,
-    LBALeafNodeRef parent,
-    uint16_t pos,
-    lba_map_val_t &val,
-    lba_node_meta_t meta)
-    : LBAMapping(
-	c,
-	parent,
-	pos,
-	val.pladdr.is_paddr() ? val.pladdr.get_paddr() : P_ADDR_NULL,
-	val.len,
-	meta),
-      key(meta.begin),
-      indirect(val.pladdr.is_laddr()),
-      intermediate_key(indirect ? val.pladdr.get_laddr() : L_ADDR_NULL),
-      intermediate_length(indirect ? val.len : 0),
-      raw_val(val.pladdr),
-      map_val(val),
-      parent_modifications(parent->modifications)
-  {}
-
-  lba_map_val_t get_map_val() const {
-    return map_val;
-  }
-
-  bool is_indirect() const final {
-    return indirect;
-  }
-
-  void make_indirect(
-    laddr_t new_key,
-    extent_len_t length,
-    laddr_t interkey = L_ADDR_NULL)
-  {
-    assert(!indirect);
-    indirect = true;
-    intermediate_base = key;
-    intermediate_length = len;
-    adjust_mutable_indirect_attrs(new_key, length, interkey);
-  }
-
-  laddr_t get_key() const final {
-    return key;
-  }
-
-  pladdr_t get_raw_val() const {
-    return raw_val;
-  }
-
-  laddr_t get_intermediate_key() const final {
-    assert(is_indirect());
-    assert(intermediate_key != L_ADDR_NULL);
-    return intermediate_key;
-  }
-
-  laddr_t get_intermediate_base() const final {
-    assert(is_indirect());
-    assert(intermediate_base != L_ADDR_NULL);
-    return intermediate_base;
-  }
-
-  extent_len_t get_intermediate_offset() const final {
-    assert(intermediate_key >= intermediate_base);
-    assert((intermediate_key == L_ADDR_NULL)
-      == (intermediate_base == L_ADDR_NULL));
-    return intermediate_key.get_byte_distance<extent_len_t>(intermediate_base);
-  }
-
-  extent_len_t get_intermediate_length() const final {
-    assert(is_indirect());
-    assert(intermediate_length);
-    return intermediate_length;
-  }
-
-  bool is_clone() const final {
-    return get_map_val().refcount > 1;
-  }
-
-  uint32_t get_checksum() const final {
-    return get_map_val().checksum;
-  }
-
-  void adjust_mutable_indirect_attrs(
-    laddr_t new_key,
-    extent_len_t length,
-    laddr_t interkey = L_ADDR_NULL)
-  {
-    assert(indirect);
-    assert(value.is_paddr());
-    intermediate_key = (interkey == L_ADDR_NULL ? key : interkey);
-    key = new_key;
-    len = length;
-  }
-
-  uint64_t get_parent_modifications() const {
-    return parent_modifications;
-  }
-
-  bool parent_modified() const final {
-    ceph_assert(parent);
-    ceph_assert(is_parent_viewable());
-    auto &p = static_cast<LBALeafNode&>(*parent);
-    return p.modified_since(parent_modifications);
-  }
-
-  void maybe_fix_pos() final {
-    assert(is_parent_viewable());
-    if (!parent_modified()) {
-      return;
-    }
-    LOG_PREFIX(BtreeLBAMapping::maybe_fix_pos);
-    auto &p = static_cast<LBALeafNode&>(*parent);
-    p.maybe_fix_mapping_pos(*this);
-    SUBDEBUGT(seastore_lba, "fixed pin {}",
-              ctx.trans, static_cast<LBAMapping&>(*this));
-  }
-
-  LBAMappingRef refresh_with_pending_parent() final {
-    LOG_PREFIX(BtreeLBAMapping::refresh_with_pending_parent);
-    assert(is_parent_valid() && !is_parent_viewable());
-    auto &p = static_cast<LBALeafNode&>(*parent);
-    auto &viewable_p = static_cast<LBALeafNode&>(
-      *p.find_pending_version(ctx.trans, get_key()));
-    auto new_pin = viewable_p.get_mapping(ctx, get_key());
-    SUBDEBUGT(seastore_lba, "new pin {}", ctx.trans, static_cast<LBAMapping&>(*new_pin));
-    return new_pin;
-  }
-  bool is_stable() const final;
-  bool is_data_stable() const final;
-  get_child_ret_t<lba_manager::btree::LBALeafNode, LogicalChildNode>
-  get_logical_extent(Transaction &t);
-
-protected:
-  LBAMappingRef _duplicate(
-    op_context_t ctx) const final {
-    auto pin = std::unique_ptr<BtreeLBAMapping>(new BtreeLBAMapping(ctx));
-    pin->key = key;
-    pin->intermediate_base = intermediate_base;
-    pin->intermediate_key = intermediate_key;
-    pin->intermediate_length = intermediate_length;
-    pin->indirect = indirect;
-    pin->raw_val = raw_val;
-    pin->map_val = map_val;
-    pin->parent_modifications = parent_modifications;
-    return pin;
-  }
-private:
-  void _new_pos(uint16_t pos) {
-    this->pos = pos;
-  }
-
-  laddr_t key = L_ADDR_NULL;
-  bool indirect = false;
-  laddr_t intermediate_key = L_ADDR_NULL;
-  laddr_t intermediate_base = L_ADDR_NULL;
-  extent_len_t intermediate_length = 0;
-  pladdr_t raw_val;
-  lba_map_val_t map_val;
-  uint64_t parent_modifications = 0;
-  friend struct LBALeafNode;
-};
-
-using BtreeLBAMappingRef = std::unique_ptr<BtreeLBAMapping>;
-
 using LBABtree = FixedKVBtree<
   laddr_t, lba_map_val_t, LBAInternalNode,
   LBALeafNode, LBACursor, LBA_BLOCK_SIZE>;