From d92be859d61c8b9d295c06ed84c65159be5675dc Mon Sep 17 00:00:00 2001
From: Vlad Lesin <vlad_lesin@mail.ru>
Date: Thu, 10 Dec 2020 21:11:26 +0300
Subject: MDEV-18976: Implement a CHECKSUM redo log record for improved
 validation

This is draft implementation without test.
---
 .../suite/innodb/t/MDEV-18976-redolog-crc.test     | 21 +++++++++
 storage/innobase/buf/buf0buf.cc                    |  4 --
 storage/innobase/fsp/fsp0fsp.cc                    |  6 +--
 storage/innobase/handler/ha_innodb.cc              |  6 +++
 storage/innobase/include/buf0types.h               |  2 +-
 storage/innobase/include/mtr0log.h                 | 26 +++++++++--
 storage/innobase/include/mtr0mtr.h                 | 43 +++++++++++++++++-
 storage/innobase/include/mtr0types.h               |  3 ++
 storage/innobase/include/srv0srv.h                 |  1 +
 storage/innobase/log/log0recv.cc                   | 33 ++++++++++++--
 storage/innobase/mtr/mtr0mtr.cc                    | 53 +++++++++++++++++++++-
 storage/innobase/srv/srv0srv.cc                    |  2 +
 12 files changed, 183 insertions(+), 17 deletions(-)
 create mode 100644 mysql-test/suite/innodb/t/MDEV-18976-redolog-crc.test

diff --git a/mysql-test/suite/innodb/t/MDEV-18976-redolog-crc.test b/mysql-test/suite/innodb/t/MDEV-18976-redolog-crc.test
new file mode 100644
index 00000000000..76503ef56a7
--- /dev/null
+++ b/mysql-test/suite/innodb/t/MDEV-18976-redolog-crc.test
@@ -0,0 +1,21 @@
+--source include/have_innodb.inc
+--source include/have_debug.inc
+
+# Disable pages flushing to allow redo log records to be executed on --prepare.
+#SET @old_debug_dbug=@@global.debug_dbug;
+SET GLOBAL debug_dbug="+d,ib_log_checkpoint_avoid";
+#SET @old_innodb_page_cleaner_disabled_debug=@@global.innodb_page_cleaner_disabled_debug;
+SET GLOBAL innodb_page_cleaner_disabled_debug=ON;
+SET GLOBAL innodb_redo_log_checksum=ON;
+
+CREATE TABLE t(i INT) ENGINE INNODB;
+INSERT INTO t VALUES (1), (2), (3), (4), (5);
+
+--source include/kill_mysqld.inc
+
+
+--source include/start_mysqld.inc
+
+DROP TABLE t;
+#SET GLOBAL innodb_page_cleaner_disabled_debug=@old_innodb_page_cleaner_disabled_debug;
+#SET GLOBAL debug_dbug=@old_debug_dbug;
diff --git a/storage/innobase/buf/buf0buf.cc b/storage/innobase/buf/buf0buf.cc
index 2ddd9f278b1..05dbe068bbf 100644
--- a/storage/innobase/buf/buf0buf.cc
+++ b/storage/innobase/buf/buf0buf.cc
@@ -2504,10 +2504,6 @@ void buf_page_free(const page_id_t page_id,
   buf_block_t *block= reinterpret_cast<buf_block_t*>
     (buf_pool.page_hash_get_low(page_id, fold));
 
-  /* TODO: try to all this part of mtr_t::free() */
-  if (srv_immediate_scrub_data_uncompressed || mtr->is_page_compressed())
-    mtr->add_freed_offset(page_id);
-
   if (!block || block->page.state() != BUF_BLOCK_FILE_PAGE)
   {
     /* FIXME: if block!=NULL, convert to BUF_BLOCK_FILE_PAGE,
diff --git a/storage/innobase/fsp/fsp0fsp.cc b/storage/innobase/fsp/fsp0fsp.cc
index ae8c557b24c..167a87077a0 100644
--- a/storage/innobase/fsp/fsp0fsp.cc
+++ b/storage/innobase/fsp/fsp0fsp.cc
@@ -2637,9 +2637,9 @@ fseg_free_extent(
 
 	for (ulint i = 0; i < FSP_EXTENT_SIZE; i++) {
 		if (!xdes_is_free(descr, i)) {
-			buf_page_free(
-			  page_id_t(space->id, first_page_in_extent + 1),
-			  mtr, __FILE__, __LINE__);
+			page_id_t freed_page_id(space->id, first_page_in_extent + 1);
+			buf_page_free(freed_page_id,  mtr, __FILE__, __LINE__);
+			mtr->add_freed_offset(freed_page_id);
 		}
 	}
 }
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 9a47fb6b30f..9cad32e1917 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -19914,6 +19914,11 @@ static MYSQL_SYSVAR_BOOL(immediate_scrub_data_uncompressed,
 			 "Enable scrubbing of data",
 			 NULL, NULL, FALSE);
 
+static MYSQL_SYSVAR_BOOL(
+  redo_log_checksum, srv_redo_log_checksum, 0,
+  "Write redo log record with page crc for each modified page on mtr commit",
+  NULL, NULL, FALSE);
+
 static MYSQL_SYSVAR_BOOL(background_scrub_data_uncompressed,
   deprecated::innodb_background_scrub_data_uncompressed,
   PLUGIN_VAR_OPCMDARG, innodb_deprecated_ignored, NULL,
@@ -20140,6 +20145,7 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(background_thread),
   MYSQL_SYSVAR(encrypt_temporary_tables),
 
+  MYSQL_SYSVAR(redo_log_checksum),
   NULL
 };
 
diff --git a/storage/innobase/include/buf0types.h b/storage/innobase/include/buf0types.h
index ba1e2e5eaa6..e2026052122 100644
--- a/storage/innobase/include/buf0types.h
+++ b/storage/innobase/include/buf0types.h
@@ -171,7 +171,7 @@ public:
     m_id= (m_id & ~uint64_t{0} << 32) | page_no;
   }
 
-  ulonglong raw() { return m_id; }
+  ulonglong raw() const { return m_id; }
 private:
   /** The page identifier */
   uint64_t m_id;
diff --git a/storage/innobase/include/mtr0log.h b/storage/innobase/include/mtr0log.h
index 2bcd69d8899..8d7ff84b1aa 100644
--- a/storage/innobase/include/mtr0log.h
+++ b/storage/innobase/include/mtr0log.h
@@ -384,8 +384,8 @@ template<byte type>
 inline byte *mtr_t::log_write(const page_id_t id, const buf_page_t *bpage,
                               size_t len, bool alloc, size_t offset)
 {
-  static_assert(!(type & 15) && type != RESERVED && type != OPTION &&
-                type <= FILE_CHECKPOINT, "invalid type");
+  static_assert(!(type & 15) && type != RESERVED && type <= FILE_CHECKPOINT,
+                "invalid type");
   ut_ad(type >= FILE_CREATE || is_named_space(id.space()));
   ut_ad(!bpage || bpage->id() == id);
   constexpr bool have_len= type != INIT_PAGE && type != FREE_PAGE;
@@ -541,9 +541,13 @@ inline void mtr_t::init(buf_block_t *b)
 inline void mtr_t::free(fil_space_t &space, uint32_t offset)
 {
   page_id_t freed_page_id(space.id, offset);
+
+  if (srv_redo_log_checksum || srv_immediate_scrub_data_uncompressed
+      || is_page_compressed())
+    add_freed_offset(freed_page_id);
+
   if (m_log_mode == MTR_LOG_ALL)
     m_log.close(log_write<FREE_PAGE>(freed_page_id, nullptr));
-
   ut_ad(!m_user_space || m_user_space == &space);
   if (&space == fil_system.sys_space)
     freed_system_tablespace_page();
@@ -673,3 +677,19 @@ inline void mtr_t::trim_pages(const page_id_t id)
   m_log.close(l);
   set_trim_pages();
 }
+
+inline void mtr_t::page_checksum(const page_id_t id, uint32_t crc,
+                                 lsn_t flushed_lsn)
+{
+  if (m_log_mode != MTR_LOG_ALL)
+    return;
+  static_assert(sizeof(crc) == 4, "compatibility");
+  static_assert(sizeof(flushed_lsn) == 8, "compatibility");
+  byte* l = log_write<OPTION>(id, nullptr, 4 + 8 + 1, true);
+  *l++ = CHECKSUM;
+  mach_write_to_4(l, crc);
+  l += 4;
+  mach_write_to_8(l, flushed_lsn);
+  l += 8;
+  m_log.close(l);
+}
diff --git a/storage/innobase/include/mtr0mtr.h b/storage/innobase/include/mtr0mtr.h
index f8ab7cf440f..7997b170434 100644
--- a/storage/innobase/include/mtr0mtr.h
+++ b/storage/innobase/include/mtr0mtr.h
@@ -344,7 +344,7 @@ public:
   /** Check if we are holding exclusive tablespace latch
   @param space  tablespace to search for
   @return whether space.latch is being held */
-  bool memo_contains(const fil_space_t& space)
+  bool memo_contains(const fil_space_t& space) const
     MY_ATTRIBUTE((warn_unused_result));
 
 
@@ -378,7 +378,7 @@ public:
 	mtr_buf_t* get_memo() { return &m_memo; }
 
   /** @return true if system tablespace page has been freed */
-  bool is_freed_system_tablespace_page()
+  bool is_freed_system_tablespace_page() const
   {
     return m_freed_in_system_tablespace;
   }
@@ -577,6 +577,9 @@ public:
   @param id       first page identifier that will not be in the file */
   inline void trim_pages(const page_id_t id);
 
+  inline void page_checksum(const page_id_t id, uint32_t crc,
+                            lsn_t flushed_lsn);
+
   /** Write a log record about a file operation.
   @param type           file operation
   @param space_id       tablespace identifier
@@ -645,6 +648,42 @@ public:
   { ut_ad(!m_commit || m_start); return m_start && !m_commit; }
   /** @return whether the mini-transaction has been committed */
   bool has_committed() const { ut_ad(!m_commit || m_start); return m_commit; }
+  bool page_is_freed(page_id_t id) const
+  {
+    if (!m_freed_pages)
+      return false;
+    fil_space_t *freed_space= m_user_space;
+    /* Get the freed tablespace in case of predefined tablespace */
+    if (!freed_space)
+    {
+      ut_ad(is_freed_system_tablespace_page());
+      freed_space= fil_system.sys_space;
+    }
+
+    ut_ad(memo_contains(*freed_space));
+
+    if (id.space() != freed_space->id)
+      return false;
+
+    return m_freed_pages->contains(id.page_no());
+  }
+  static uint32_t page_crc(const byte* page)
+  {
+    /* Since the field FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION, and in
+       versions <= 4.1.x FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID, are written
+       outside the buffer pool to the first pages of data files, we have to
+       skip them in the page checksum calculation. We must also skip the
+       field FIL_PAGE_SPACE_OR_CHKSUM where the checksum is stored, and also
+       the last 8 bytes of page because there we store the old formula
+       checksum. */
+    return static_cast<uint32_t>(
+      ut_fold_binary(page + FIL_PAGE_OFFSET, FIL_PAGE_LSN - FIL_PAGE_OFFSET)
+      + ut_fold_binary(page + FIL_PAGE_TYPE,
+                       FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION - FIL_PAGE_PREV)
+      + ut_fold_binary(page + FIL_PAGE_DATA, srv_page_size - FIL_PAGE_DATA
+                                               - FIL_PAGE_END_LSN_OLD_CHKSUM));
+  }
+
 private:
   /** whether start() has been called */
   bool m_start= false;
diff --git a/storage/innobase/include/mtr0types.h b/storage/innobase/include/mtr0types.h
index d1b6784ae86..d7c5ccc6baa 100644
--- a/storage/innobase/include/mtr0types.h
+++ b/storage/innobase/include/mtr0types.h
@@ -289,6 +289,9 @@ enum mrec_ext_t
   TRIM_PAGES= 10
 };
 
+enum mrec_opt_t {
+  CHECKSUM
+};
 
 /** Redo log record types for file-level operations. These bit
 patterns will be written to redo log files, so the existing codes or
diff --git a/storage/innobase/include/srv0srv.h b/storage/innobase/include/srv0srv.h
index 7b65000c115..c6cb789dce9 100644
--- a/storage/innobase/include/srv0srv.h
+++ b/storage/innobase/include/srv0srv.h
@@ -410,6 +410,7 @@ extern ulong	srv_max_purge_lag_delay;
 extern my_bool	innodb_encrypt_temporary_tables;
 
 extern my_bool  srv_immediate_scrub_data_uncompressed;
+extern my_bool  srv_redo_log_checksum;
 /*-------------------------------------------*/
 
 /** Modes of operation */
diff --git a/storage/innobase/log/log0recv.cc b/storage/innobase/log/log0recv.cc
index fe691a4b256..117e791ddff 100644
--- a/storage/innobase/log/log0recv.cc
+++ b/storage/innobase/log/log0recv.cc
@@ -266,7 +266,6 @@ public:
       next_not_same_page:
           last_offset= 1; /* the next record must not be same_page  */
         }
-      next:
         l+= rlen;
         continue;
       }
@@ -280,7 +279,32 @@ public:
 
       switch (b & 0x70) {
       case OPTION:
-        goto next;
+        {
+        if (UNIV_UNLIKELY(rlen != 1 + 4 + 8 || *l != CHECKSUM))
+          goto record_corrupted;
+        ++l;
+        uint32_t crc = mach_read_from_4(l);
+        l += 4;
+//        lsn_t flushed_lsn = mach_read_from_8(l);
+        l += 8;
+        uint32_t calc_crc = mtr_t::page_crc(frame);
+//        lsn_t flushed_lsn_from_page = mach_read_from_8(frame + FIL_PAGE_LSN);
+        if (calc_crc != crc) {
+          ib::warn() << "Page checksum stored in redo log record " << crc
+                      << " does not match counted checksum " << calc_crc
+                      << " for page " << block.page.id();
+        }
+        /*
+        if (flushed_lsn_from_page != flushed_lsn) {
+          ib::warn() << "Page LSN stored in redo log record " << flushed_lsn
+                      << " does not match " << flushed_lsn_from_page
+                      << " stored on page " << block.page.id();
+          failed = true;
+        }
+        */
+        applied = APPLIED_YES;
+        continue;
+      }
       case EXTENDED:
         if (UNIV_UNLIKELY(block.page.id().page_no() < 3 ||
                           block.page.zip.ssize))
@@ -1970,8 +1994,11 @@ same_page:
         }
         last_offset= FIL_PAGE_TYPE;
         break;
-      case RESERVED:
       case OPTION:
+        if (UNIV_UNLIKELY(rlen != 1 + 4 + 8 || *l != CHECKSUM))
+          goto record_corrupted;
+        break;
+      case RESERVED:
         continue;
       case WRITE:
       case MEMMOVE:
diff --git a/storage/innobase/mtr/mtr0mtr.cc b/storage/innobase/mtr/mtr0mtr.cc
index 60c91364b15..cfe0aed162a 100644
--- a/storage/innobase/mtr/mtr0mtr.cc
+++ b/storage/innobase/mtr/mtr0mtr.cc
@@ -32,6 +32,7 @@ Created 11/26/1995 Heikki Tuuri
 #include "page0types.h"
 #include "mtr0log.h"
 #include "log0recv.h"
+#include <unordered_set>
 
 /** Iterate over a memo block in reverse. */
 template <typename Functor>
@@ -300,6 +301,50 @@ struct ReleaseAll {
   }
 };
 
+
+class WriteOptionCRC {
+public:
+  WriteOptionCRC(mtr_t &mtr) : m_mtr(mtr) {}
+  /** @return true always. */
+  bool operator()(mtr_memo_slot_t *slot)
+  {
+    if (slot->type & MTR_MEMO_MODIFY)
+    {
+#ifdef UNIV_DEBUG
+      switch (slot->type & ~MTR_MEMO_MODIFY) {
+        case MTR_MEMO_BUF_FIX:
+        case MTR_MEMO_PAGE_S_FIX:
+        case MTR_MEMO_PAGE_SX_FIX:
+        case MTR_MEMO_PAGE_X_FIX:
+          break;
+        default:
+          ut_ad("invalid type" == 0);
+          break;
+      }
+#endif /* UNIV_DEBUG */
+      buf_block_t *block= reinterpret_cast<buf_block_t*>(slot->object);
+      byte *page = block->frame;
+      ulonglong page_id_raw = block->page.id().raw();
+      if (!m_visited_pages.count(page_id_raw)) {
+        static_assert(FIL_PAGE_SPACE_OR_CHKSUM == FIL_PAGE_OFFSET - 4,
+                      "compatibility");
+        static_assert(FIL_PAGE_TYPE == FIL_PAGE_LSN + 8, "compatibility");
+        uint32_t crc = mtr_t::page_crc(page);
+        lsn_t lsn = mach_read_from_8(page + FIL_PAGE_LSN);
+       if (!m_mtr.page_is_freed(block->page.id()))
+          m_mtr.page_checksum(block->page.id(), crc, lsn);
+        m_visited_pages.insert(page_id_raw);
+      }
+    }
+    return true;
+  }
+
+private:
+  mtr_t &m_mtr;
+  std::unordered_set<ulonglong> m_visited_pages;
+};
+
+
 #ifdef UNIV_DEBUG
 /** Check that all slots have been handled. */
 struct DebugCheck {
@@ -400,6 +445,12 @@ void mtr_t::commit()
   {
     ut_ad(!srv_read_only_mode || m_log_mode == MTR_LOG_NO_REDO);
 
+    if (srv_redo_log_checksum)
+    {
+      Iterate<WriteOptionCRC> iteration(WriteOptionCRC(*this));
+      m_memo.for_each_block(iteration);
+    }
+
     std::pair<lsn_t,bool> lsns;
 
     if (const ulint len= prepare_write())
@@ -969,7 +1020,7 @@ bool mtr_t::memo_contains(const rw_lock_t &lock, mtr_memo_type_t type)
 /** Check if we are holding exclusive tablespace latch
 @param space  tablespace to search for
 @return whether space.latch is being held */
-bool mtr_t::memo_contains(const fil_space_t& space)
+bool mtr_t::memo_contains(const fil_space_t& space) const
 {
   Iterate<Find> iteration(Find(&space, MTR_MEMO_SPACE_X_LOCK));
   if (m_memo.for_each_block_in_reverse(iteration))
diff --git a/storage/innobase/srv/srv0srv.cc b/storage/innobase/srv/srv0srv.cc
index 71ae6e04881..f8fdbbb1443 100644
--- a/storage/innobase/srv/srv0srv.cc
+++ b/storage/innobase/srv/srv0srv.cc
@@ -392,6 +392,8 @@ my_bool innodb_encrypt_temporary_tables;
 
 my_bool srv_immediate_scrub_data_uncompressed;
 
+my_bool srv_redo_log_checksum;
+
 /* Array of English strings describing the current state of an
 i/o handler thread */
 
-- 
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