caching/superblock.{h,cc}

Makefile.in

@@ -48,7 +48,7 @@ PDATA_SOURCE=\
 SOURCE=\
 	$(PDATA_SOURCE) \
 	\
-	cache/metadata_disk_structures.cc \
+	caching/superblock.cc \
 	\
 	thin-provisioning/device_tree.cc \
 	thin-provisioning/file_utils.cc \
@@ -66,7 +66,7 @@ SOURCE=\
 PDATA_OBJECTS=$(subst .cc,.o,$(SOURCE))
 
 CXX_PROGRAM_SOURCE=\
-	cache/check.cc \
+	caching/check.cc \
 	\
 	thin-provisioning/thin_check.cc \
 	thin-provisioning/thin_dump.cc \
@@ -228,11 +228,11 @@ CACHE_CHECK_SOURCE=\
 	persistent-data/space-maps/recursive.cc \
 	persistent-data/space-maps/careful_alloc.cc \
 	persistent-data/transaction_manager.cc \
-	cache/metadata_disk_structures.cc
+	caching/superblock.cc
 
 CACHE_CHECK_OBJECTS=$(subst .cc,.o,$(CACHE_CHECK_SOURCE))
 
-cache_check: $(CACHE_CHECK_OBJECTS) cache/check.o
+cache_check: $(CACHE_CHECK_OBJECTS) caching/check.o
 	@echo "    [LD]  $@"
 	$(V) $(CXX) $(CXXFLAGS) $(LDFLAGS) -o $@ $+ $(LIBS)
 

cache/metadata_disk_structures.h

@@ -1,120 +0,0 @@
-// Copyright (C) 2012 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_DISK_STRUCTURES_H
-#define CACHE_METADATA_DISK_STRUCTURES_H
-
-#include "persistent-data/endian_utils.h"
-#include "persistent-data/data-structures/btree.h"
-
-//----------------------------------------------------------------
-
-// FIXME: rename to just METADATA_DISK_STRUCTURES
-namespace cache_tools {
-	using namespace base;	// FIXME: don't use namespaces in headers.
-
-	unsigned const SPACE_MAP_ROOT_SIZE = 128;
-	unsigned const CACHE_POLICY_NAME_SIZE = 16;
-	unsigned const CACHE_POLICY_VERSION_SIZE = 3;
-
-	typedef unsigned char __u8;
-
-	struct superblock_disk {
-		le32 csum;
-		le32 flags;
-		le64 blocknr;
-
-		__u8 uuid[16];
-		le64 magic;
-		le32 version;
-
-		__u8 policy_name[CACHE_POLICY_NAME_SIZE];
-		le32 policy_version[CACHE_POLICY_VERSION_SIZE];
-		le32 policy_hint_size;
-
-		__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
-
-		le64 mapping_root;
-		le64 hint_root;
-
-		le64 discard_root;
-		le64 discard_block_size;
-		le64 discard_nr_blocks;
-
-		le32 data_block_size; /* in 512-byte sectors */
-		le32 metadata_block_size; /* in 512-byte sectors */
-		le32 cache_blocks;
-
-		le32 compat_flags;
-		le32 compat_ro_flags;
-		le32 incompat_flags;
-
-		le32 read_hits;
-		le32 read_misses;
-		le32 write_hits;
-		le32 write_misses;
-	} __attribute__ ((packed));
-
-	struct superblock {
-		uint32_t csum;
-		uint32_t flags;
-		uint64_t blocknr;
-
-		__u8 uuid[16];
-		uint64_t magic;
-		uint32_t version;
-
-		__u8 policy_name[CACHE_POLICY_NAME_SIZE];
-		uint32_t policy_version[CACHE_POLICY_VERSION_SIZE];
-		uint32_t policy_hint_size;
-
-		__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
-
-		uint64_t mapping_root;
-		uint64_t hint_root;
-
-		uint64_t discard_root;
-		uint64_t discard_block_size;
-		uint64_t discard_nr_blocks;
-
-		uint32_t data_block_size; /* in 512-byte sectors */
-		uint32_t metadata_block_size; /* in 512-byte sectors */
-		uint32_t cache_blocks;
-
-		uint32_t compat_flags;
-		uint32_t compat_ro_flags;
-		uint32_t incompat_flags;
-
-		uint32_t read_hits;
-		uint32_t read_misses;
-		uint32_t write_hits;
-		uint32_t write_misses;
-	};
-
-	struct superblock_traits {
-		typedef superblock_disk disk_type;
-		typedef superblock value_type;
-
-		static void unpack(superblock_disk const &disk, superblock &value);
-		static void pack(superblock const &value, superblock_disk &disk);
-	};
-}
-
-//----------------------------------------------------------------
-
-#endif

caching/metadata_disk_structures.cc

@@ -0,0 +1,28 @@
+// Copyright (C) 2012 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/>.
+
+#include "metadata_disk_structures.h"
+
+#include <string.h>
+
+using namespace cache_tools;
+
+//----------------------------------------------------------------
+
+
+//----------------------------------------------------------------

caching/metadata_disk_structures.h

@@ -0,0 +1,35 @@
+// Copyright (C) 2012 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_DISK_STRUCTURES_H
+#define CACHE_METADATA_DISK_STRUCTURES_H
+
+#include "persistent-data/endian_utils.h"
+#include "persistent-data/data-structures/btree.h"
+
+//----------------------------------------------------------------
+
+// FIXME: rename to just METADATA_DISK_STRUCTURES
+namespace cache_tools {
+	using namespace base;	// FIXME: don't use namespaces in headers.
+
+}
+
+//----------------------------------------------------------------
+
+#endif

caching/superblock.cc

@@ -1,26 +1,7 @@
-// Copyright (C) 2012 Red Hat, Inc. All rights reserved.
+#include "caching/superblock.h"
-//
-// 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/>.
 
-#include "metadata_disk_structures.h"
+using namespace caching;
-
+using namespace superblock_detail;
-#include <string.h>
-
-using namespace cache_tools;
 
 //----------------------------------------------------------------
 
@@ -110,4 +91,87 @@ superblock_traits::pack(superblock const &core, superblock_disk &disk)
 	disk.write_misses = to_disk<le32>(core.write_misses);
 }
 
+//--------------------------------
+
+superblock_corruption::superblock_corruption(std::string const &desc)
+	: desc_(desc)
+{
+}
+
+void
+superblock_corruption::visit(damage_visitor &v) const
+{
+	v.visit(*this);
+}
+
+//--------------------------------
+
+namespace {
+	using namespace persistent_data;
+	using namespace superblock_detail;
+
+        uint32_t const VERSION = 1;
+        unsigned const SECTOR_TO_BLOCK_SHIFT = 3;
+	uint32_t const SUPERBLOCK_CSUM_SEED = 9031977;
+
+	struct sb_validator : public block_manager<>::validator {
+		virtual void check(buffer<> const &b, block_address location) const {
+			superblock_disk const *sbd = reinterpret_cast<superblock_disk const *>(&b);
+			crc32c sum(SUPERBLOCK_CSUM_SEED);
+			sum.append(&sbd->flags, MD_BLOCK_SIZE - sizeof(uint32_t));
+			if (sum.get_sum() != to_cpu<uint32_t>(sbd->csum))
+				throw checksum_error("bad checksum in superblock");
+		}
+
+		virtual void prepare(buffer<> &b, block_address location) const {
+			superblock_disk *sbd = reinterpret_cast<superblock_disk *>(&b);
+			crc32c sum(SUPERBLOCK_CSUM_SEED);
+			sum.append(&sbd->flags, MD_BLOCK_SIZE - sizeof(uint32_t));
+			sbd->csum = to_disk<base::le32>(sum.get_sum());
+		}
+	};
+}
+
+persistent_data::block_manager<>::validator::ptr
+caching::superblock_validator()
+{
+	return block_manager<>::validator::ptr(new sb_validator);
+}
+
+//--------------------------------
+
+superblock_detail::superblock
+caching::read_superblock(persistent_data::block_manager<>::ptr bm,
+			 persistent_data::block_address location)
+{
+	using namespace superblock_detail;
+
+	superblock sb;
+	block_manager<>::read_ref r = bm->read_lock(location, superblock_validator());
+	superblock_disk const *sbd = reinterpret_cast<superblock_disk const *>(&r.data());
+	superblock_traits::unpack(*sbd, sb);
+
+	return sb;
+}
+
+superblock_detail::superblock
+caching::read_superblock(persistent_data::block_manager<>::ptr bm)
+{
+	return read_superblock(bm, SUPERBLOCK_LOCATION);
+}
+
+void
+caching::check_superblock(persistent_data::block_manager<>::ptr bm,
+			  superblock_detail::damage_visitor &visitor)
+{
+	using namespace superblock_detail;
+
+	try {
+		bm->read_lock(SUPERBLOCK_LOCATION, superblock_validator());
+
+	} catch (std::exception const &e) {
+		visitor.visit(superblock_corruption(e.what()));
+	}
+}
+
 //----------------------------------------------------------------

caching/superblock.h

@@ -0,0 +1,139 @@
+#ifndef CACHE_SUPERBLOCK_H
+#define CACHE_SUPERBLOCK_H
+
+#include "persistent-data/endian_utils.h"
+#include "persistent-data/data-structures/btree.h"
+
+//----------------------------------------------------------------
+
+namespace caching {
+	namespace superblock_detail {
+		using namespace base;
+
+		unsigned const SPACE_MAP_ROOT_SIZE = 128;
+		unsigned const CACHE_POLICY_NAME_SIZE = 16;
+		unsigned const CACHE_POLICY_VERSION_SIZE = 3;
+
+		typedef unsigned char __u8;
+
+		struct superblock_disk {
+			le32 csum;
+			le32 flags;
+			le64 blocknr;
+
+			__u8 uuid[16];
+			le64 magic;
+			le32 version;
+
+			__u8 policy_name[CACHE_POLICY_NAME_SIZE];
+			le32 policy_version[CACHE_POLICY_VERSION_SIZE];
+			le32 policy_hint_size;
+
+			__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
+
+			le64 mapping_root;
+			le64 hint_root;
+
+			le64 discard_root;
+			le64 discard_block_size;
+			le64 discard_nr_blocks;
+
+			le32 data_block_size; /* in 512-byte sectors */
+			le32 metadata_block_size; /* in 512-byte sectors */
+			le32 cache_blocks;
+
+			le32 compat_flags;
+			le32 compat_ro_flags;
+			le32 incompat_flags;
+
+			le32 read_hits;
+			le32 read_misses;
+			le32 write_hits;
+			le32 write_misses;
+		} __attribute__ ((packed));
+
+		struct superblock {
+			uint32_t csum;
+			uint32_t flags;
+			uint64_t blocknr;
+
+			__u8 uuid[16];
+			uint64_t magic;
+			uint32_t version;
+
+			__u8 policy_name[CACHE_POLICY_NAME_SIZE];
+			uint32_t policy_version[CACHE_POLICY_VERSION_SIZE];
+			uint32_t policy_hint_size;
+
+			__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
+
+			uint64_t mapping_root;
+			uint64_t hint_root;
+
+			uint64_t discard_root;
+			uint64_t discard_block_size;
+			uint64_t discard_nr_blocks;
+
+			uint32_t data_block_size; /* in 512-byte sectors */
+			uint32_t metadata_block_size; /* in 512-byte sectors */
+			uint32_t cache_blocks;
+
+			uint32_t compat_flags;
+			uint32_t compat_ro_flags;
+			uint32_t incompat_flags;
+
+			uint32_t read_hits;
+			uint32_t read_misses;
+			uint32_t write_hits;
+			uint32_t write_misses;
+		};
+
+		struct superblock_traits {
+			typedef superblock_disk disk_type;
+			typedef superblock value_type;
+
+			static void unpack(superblock_disk const &disk, superblock &value);
+			static void pack(superblock const &value, superblock_disk &disk);
+		};
+
+		block_address const SUPERBLOCK_LOCATION = 0;
+		uint32_t const SUPERBLOCK_MAGIC = 06142003;
+
+		//--------------------------------
+
+		class damage_visitor;
+
+		struct damage {
+			virtual ~damage() {}
+			virtual void visit(damage_visitor &v) const = 0;
+		};
+
+		struct superblock_corruption : public damage {
+			superblock_corruption(std::string const &desc);
+			void visit(damage_visitor &v) const;
+
+			std::string desc_;
+		};
+
+		class damage_visitor {
+		public:
+			virtual ~damage_visitor() {}
+
+			void visit(damage const &d);
+
+			virtual void visit(superblock_corruption const &d) = 0;
+		};
+	}
+
+	persistent_data::block_manager<>::validator::ptr superblock_validator();
+
+	superblock_detail::superblock read_superblock(persistent_data::block_manager<>::ptr bm);
+	superblock_detail::superblock read_superblock(persistent_data::block_manager<>::ptr bm,
+						      persistent_data::block_address location);
+	void check_superblock(persistent_data::block_manager<>::ptr bm,
+			      superblock_detail::damage_visitor &visitor);
+}
+
+//----------------------------------------------------------------
+
+#endif