caching/superblock.{h,cc}

caching/cache_metadata.h

@@ -0,0 +1,143 @@
+// Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+//
+// This file is part of the thin-provisioning-tools source.
+//
+// thin-provisioning-tools is free software: you can redistribute it
+// and/or modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// thin-provisioning-tools is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+// of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with thin-provisioning-tools.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef CACHE_METADATA_H
+#define CACHE_METADATA_H
+
+#include "block.h"
+#include "array.h"
+#include "endian_utils.h"
+#include "space_map_disk.h"
+#include "transaction_manager.h"
+
+//----------------------------------------------------------------
+
+namespace cache {
+	// FIXME: don't use namespaces in a header
+	using namespace base;
+	using namespace persistent_data;
+
+	block_address const SUPERBLOCK_LOCATION = 0;
+
+	typedef uint64_t sector_t;
+
+	//------------------------------------------------
+
+	class space_map_ref_counter {
+	public:
+		space_map_ref_counter(space_map::ptr sm)
+			: sm_(sm) {
+		}
+
+		void inc(block_address b) {
+			sm_->inc(b);
+		}
+
+		void dec(block_address b) {
+			sm_->dec(b);
+		}
+
+	private:
+		space_map::ptr sm_;
+	};
+
+	struct block_flags {
+		uint64_t block_;
+		uint32_t flags_;
+	};
+
+	class block_flags_ref_counter {
+	public:
+		block_flags_ref_counter(space_map::ptr sm)
+			: sm_(sm) {
+		}
+
+		void inc(block_flags bf) {
+			sm_->inc(bf.block_);
+		}
+
+		void dec(block_flags bf) {
+			sm_->dec(bf.block_);
+		}
+
+	private:
+		space_map::ptr sm_;
+	};
+
+	struct block_traits {
+		typedef base::__le64 disk_type;
+		typedef block_flags value_type;
+		typedef block_flags_ref_counter ref_counter;
+
+		static void unpack(disk_type const &disk, value_type &value) {
+			uint64_t v = to_cpu<uint64_t>(disk);
+			value.block_ = v >> 24;
+			value.flags_ = v & ((1 << 24) - 1);
+		}
+
+		static void pack(value_type const &value, disk_type &disk) {
+			uint64_t v = (value.block_ << 24) | value.flags_;
+			disk = base::to_disk<base::__le64>(v);
+		}
+	};
+
+	//------------------------------------------------
+
+	// FIXME: should these be in a sub-namespace?
+	typedef persistent_data::transaction_manager::ptr tm_ptr;
+	typedef persistent_data::btree<1, device_details_traits> detail_tree;
+	typedef persistent_data::btree<1, mtree_traits> dev_tree;
+	typedef persistent_data::btree<2, block_traits> mapping_tree;
+	typedef persistent_data::btree<1, block_traits> single_mapping_tree;
+
+	// The tools require different interfaces onto the metadata than
+	// the in kernel driver.  This class gives access to the low-level
+	// implementation of metadata.  Implement more specific interfaces
+	// on top of this.
+	struct metadata {
+		enum open_type {
+			CREATE,
+			OPEN
+		};
+
+		metadata(std::string const &dev_path, open_type ot,
+			 sector_t data_block_size = 128,
+			 block_address nr_cache_blocks = 0); // Only used if CREATE
+
+		metadata(std::string const &dev_path, block_address metadata_snap);
+
+		void commit();
+
+		typedef block_manager<>::read_ref read_ref;
+		typedef block_manager<>::write_ref write_ref;
+		typedef boost::shared_ptr<metadata> ptr;
+
+		tm_ptr tm_;
+		superblock sb_;
+
+		checked_space_map::ptr metadata_sm_;
+		checked_space_map::ptr data_sm_;
+		detail_tree::ptr details_;
+		dev_tree::ptr mappings_top_level_;
+		mapping_tree::ptr mappings_;
+	};
+}
+
+//----------------------------------------------------------------
+
+#endif