XtraDB 1.1.8-29.0

23 files changed, 2019 insertions, 65 deletions

diff --git a/storage/xtradb/CMakeLists.txt b/storage/xtradb/CMakeLists.txt
index 1d2b0b29dea..4c098049fd4 100644
--- a/storage/xtradb/CMakeLists.txt
+++ b/storage/xtradb/CMakeLists.txt
@@ -91,12 +91,41 @@ IF(NOT CMAKE_CROSSCOMPILING)
   }"
   HAVE_IB_GCC_ATOMIC_BUILTINS
   )
+  CHECK_C_SOURCE_RUNS(
+  "
+  #include <stdint.h>
+  int main()
+  {
+    int64_t x, y, res;
+
+    x = 10;
+    y = 123;
+    res = __sync_bool_compare_and_swap(&x, x, y);
+    if (!res || x != y) {
+      return(1);
+    }
+
+    x = 10;
+    y = 123;
+    res = __sync_add_and_fetch(&x, y);
+    if (res != 123 + 10 || x != 123 + 10) {
+      return(1);
+    }
+
+    return(0);
+  }"
+  HAVE_IB_GCC_ATOMIC_BUILTINS_64
+  )
 ENDIF()
 
 IF(HAVE_IB_GCC_ATOMIC_BUILTINS)
  ADD_DEFINITIONS(-DHAVE_IB_GCC_ATOMIC_BUILTINS=1)
 ENDIF()
 
+IF(HAVE_IB_GCC_ATOMIC_BUILTINS_64)
+ ADD_DEFINITIONS(-DHAVE_IB_GCC_ATOMIC_BUILTINS_64=1)
+ENDIF()
+
  # either define HAVE_IB_ATOMIC_PTHREAD_T_GCC or not
 IF(NOT CMAKE_CROSSCOMPILING)
   CHECK_C_SOURCE_RUNS(
@@ -240,7 +269,7 @@ SET(INNOBASE_SOURCES	btr/btr0btr.c btr/btr0cur.c btr/btr0pcur.c btr/btr0sea.c
 			ibuf/ibuf0ibuf.c
 			pars/lexyy.c pars/pars0grm.c pars/pars0opt.c pars/pars0pars.c pars/pars0sym.c
 			lock/lock0lock.c lock/lock0iter.c
-			log/log0log.c log/log0recv.c
+			log/log0log.c log/log0recv.c log/log0online.c
 			mach/mach0data.c
 			mem/mem0mem.c mem/mem0pool.c
 			mtr/mtr0log.c mtr/mtr0mtr.c
diff --git a/storage/xtradb/btr/btr0sea.c b/storage/xtradb/btr/btr0sea.c
index 855ab62c42f..7e9449a6474 100644
--- a/storage/xtradb/btr/btr0sea.c
+++ b/storage/xtradb/btr/btr0sea.c
@@ -183,6 +183,15 @@ btr_search_sys_create(
 	//rw_lock_create(btr_search_latch_key, &btr_search_latch,
 	//	       SYNC_SEARCH_SYS);
 
+	/* PS bug lp:1018264 - Multiple hash index partitions causes overly
+	   large hash index: When multiple adaptive hash index partitions are
+	   specified, _each_ partition was being created with hash_size which
+	   should be 1/64 of the total size of all buffer pools which is
+	   incorrect and can cause overly high memory usage. hash_size
+	   should be representing the _total_ size of all partitions, not the
+	   individual size of each partition. */
+	hash_size /= btr_search_index_num;
+
 	btr_search_sys = mem_alloc(sizeof(btr_search_sys_t));
 
 	/* btr_search_index_num should be <= 32. (bits of trx->has_search_latch) */
diff --git a/storage/xtradb/buf/buf0buf.c b/storage/xtradb/buf/buf0buf.c
index a2ff171e0c5..6ce77372dac 100644
--- a/storage/xtradb/buf/buf0buf.c
+++ b/storage/xtradb/buf/buf0buf.c
@@ -2838,6 +2838,7 @@ wait_until_unfixed:
 	    && ibuf_debug) {
 		/* Try to evict the block from the buffer pool, to use the
 		insert buffer (change buffer) as much as possible. */
+		ulint	page_no	= buf_block_get_page_no(block);
 
 		if (buf_LRU_free_block(&block->page, TRUE, FALSE)) {
 			mutex_exit(block_mutex);
@@ -2864,6 +2865,18 @@ wait_until_unfixed:
 				"innodb_change_buffering_debug evict %u %u\n",
 				(unsigned) space, (unsigned) offset);
 			return(NULL);
+		} else if (UNIV_UNLIKELY(buf_block_get_state(block)
+					 != BUF_BLOCK_FILE_PAGE
+				|| (buf_block_get_page_no(block) != page_no)
+				|| (buf_block_get_space(block) != space))) {
+
+				/* buf_LRU_free_block temporarily releases the
+				block mutex, and now block points to something
+				else. */
+				mutex_exit(block_mutex);
+				block = NULL;
+				goto loop2;
+
 		} else if (buf_flush_page_try(buf_pool, block)) {
 			fprintf(stderr,
 				"innodb_change_buffering_debug flush %u %u\n",
diff --git a/storage/xtradb/buf/buf0lru.c b/storage/xtradb/buf/buf0lru.c
index 16a91358080..e8300107f3d 100644
--- a/storage/xtradb/buf/buf0lru.c
+++ b/storage/xtradb/buf/buf0lru.c
@@ -2531,6 +2531,14 @@ func_exit:
 Dump the LRU page list to the specific file. */
 #define LRU_DUMP_FILE "ib_lru_dump"
 #define LRU_DUMP_TEMP_FILE "ib_lru_dump.tmp"
+#define LRU_OS_FILE_WRITE() \
+	os_file_write(LRU_DUMP_FILE, dump_file, buffer, \
+		(buffers << UNIV_PAGE_SIZE_SHIFT) & 0xFFFFFFFFUL, \
+		(buffers >> (32 - UNIV_PAGE_SIZE_SHIFT)), \
+		buffer_size)
+#define LRU_DUMP_PAGE_COUNT	1	/* Specifies how many dump pages
+					   should be filled for each hold
+					   of the LRU_list_mutex. */
 
 UNIV_INTERN
 ibool
@@ -2541,23 +2549,30 @@ buf_LRU_file_dump(void)
 	ibool		success;
 	byte*		buffer_base = NULL;
 	byte*		buffer = NULL;
+	const ulint	buffer_size = LRU_DUMP_PAGE_COUNT * UNIV_PAGE_SIZE;
 	buf_page_t*	bpage;
+	buf_page_t*	first_bpage;
 	ulint		buffers;
 	ulint		offset;
-	ibool		ret = FALSE;
+	ulint		pages_written;
 	ulint		i;
+	ulint		total_pages;
+
+	/* Sanity test to make sure page size is a multiple of 
+	   assumed dump record size */
+	ut_a(UNIV_PAGE_SIZE % 8 == 0);
 
 	for (i = 0; i < srv_n_data_files; i++) {
 		if (strstr(srv_data_file_names[i], LRU_DUMP_FILE) != NULL) {
 			fprintf(stderr,
 				" InnoDB: The name '%s' seems to be used for"
-				" innodb_data_file_path. For safety, dumping of the LRU list"
-				" is not being done.\n", LRU_DUMP_FILE);
+				" innodb_data_file_path. Dumping LRU list is"
+				"  not done for safeness.\n", LRU_DUMP_FILE);
 			goto end;
 		}
 	}
 
-	buffer_base = ut_malloc(2 * UNIV_PAGE_SIZE);
+	buffer_base = ut_malloc(UNIV_PAGE_SIZE + buffer_size);
 	buffer = ut_align(buffer_base, UNIV_PAGE_SIZE);
 	if (!buffer) {
 		fprintf(stderr,
@@ -2577,18 +2592,28 @@ buf_LRU_file_dump(void)
 	}
 
 	buffers = offset = 0;
-
 	for (i = 0; i < srv_buf_pool_instances; i++) {
 		buf_pool_t*	buf_pool;
 
 		buf_pool = buf_pool_from_array(i);
 
 		mutex_enter(&buf_pool->LRU_list_mutex);
-		bpage = UT_LIST_GET_LAST(buf_pool->LRU);
+		bpage = first_bpage = UT_LIST_GET_FIRST(buf_pool->LRU);
+		total_pages = UT_LIST_GET_LEN(buf_pool->LRU);
 
-		while (bpage != NULL) {
-			if (offset == 0) {
-				memset(buffer, 0, UNIV_PAGE_SIZE);
+		pages_written = 0;
+		while (bpage != NULL && (pages_written++ < total_pages)) {
+
+			buf_page_t* next_bpage = UT_LIST_GET_NEXT(LRU, bpage);
+
+			if (next_bpage == first_bpage) {
+				/* Do not release list mutex here, it will be
+				   released just outside this while loop */
+				fprintf(stderr,
+					"InnoDB: detected cycle in LRU for"
+					" buffer pool %lu, skipping to next"
+					" buffer pool.\n", i);
+				break;
 			}
 
 			mach_write_to_4(buffer + offset * 4, bpage->space);
@@ -2596,52 +2621,71 @@ buf_LRU_file_dump(void)
 			mach_write_to_4(buffer + offset * 4, bpage->offset);
 			offset++;
 
-			if (offset == UNIV_PAGE_SIZE/4) {
+			ut_a(offset <= buffer_size);
+			if (offset == buffer_size/4) {
+				mutex_t		*next_block_mutex = NULL;
+
 				if (srv_shutdown_state != SRV_SHUTDOWN_NONE) {
-					success = 0;
+					mutex_exit(&buf_pool->LRU_list_mutex);
+					success = FALSE;
 					fprintf(stderr,
 						" InnoDB: stopped dumping lru"
 						" pages because of server"
 						" shutdown.\n");
+					goto end;
+				}
+
+				/* While writing file, release buffer pool
+				   mutex but keep the next page fixed so we
+				   don't worry about our list iterator becoming
+				   invalid */
+				if (next_bpage) {
+					next_block_mutex = buf_page_get_mutex(
+								next_bpage);
+
+					mutex_enter(next_block_mutex);
+					next_bpage->buf_fix_count++;
+					mutex_exit(next_block_mutex);
+				}
+				mutex_exit(&buf_pool->LRU_list_mutex);
+
+				success = LRU_OS_FILE_WRITE();
+
+				/* Grab this here so that next_bpage can't
+				   be purged when we drop the fix_count */
+				mutex_enter(&buf_pool->LRU_list_mutex);
+
+				if (next_bpage) {
+					mutex_enter(next_block_mutex);
+					next_bpage->buf_fix_count--;
+					mutex_exit(next_block_mutex);
 				}
-				success = os_file_write(LRU_DUMP_FILE, dump_file, buffer,
-						(buffers << UNIV_PAGE_SIZE_SHIFT) & 0xFFFFFFFFUL,
-						(buffers >> (32 - UNIV_PAGE_SIZE_SHIFT)),
-						UNIV_PAGE_SIZE);
+
 				if (!success) {
 					mutex_exit(&buf_pool->LRU_list_mutex);
 					fprintf(stderr,
-						" InnoDB: cannot write page %lu of %s\n",
+						" InnoDB: cannot write page"
+						" %lu of %s\n",
 						buffers, LRU_DUMP_FILE);
 					goto end;
 				}
 				buffers++;
 				offset = 0;
-			}
 
-			bpage = UT_LIST_GET_PREV(LRU, bpage);
-		}
+				bpage = next_bpage;
+			} else {
+				bpage = UT_LIST_GET_NEXT(LRU, bpage);
+			}
+		} /* while(bpage ...) */
 		mutex_exit(&buf_pool->LRU_list_mutex);
-	}
-
-	if (offset == 0) {
-		memset(buffer, 0, UNIV_PAGE_SIZE);
-	}
+	} /* for(srv_buf_pool_instances ...) */
 
 	mach_write_to_4(buffer + offset * 4, 0xFFFFFFFFUL);
 	offset++;
 	mach_write_to_4(buffer + offset * 4, 0xFFFFFFFFUL);
 	offset++;
 
-	success = os_file_write(LRU_DUMP_FILE, dump_file, buffer,
-			(buffers << UNIV_PAGE_SIZE_SHIFT) & 0xFFFFFFFFUL,
-			(buffers >> (32 - UNIV_PAGE_SIZE_SHIFT)),
-			UNIV_PAGE_SIZE);
-	if (!success) {
-		goto end;
-	}
-
-	ret = TRUE;
+	success = LRU_OS_FILE_WRITE();
 end:
 	if (dump_file != (os_file_t) -1) {
 		if (success) {
@@ -2656,7 +2700,7 @@ end:
 	if (buffer_base)
 		ut_free(buffer_base);
 
-	return(ret);
+	return(success);
 }
 
 typedef struct {
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index d37bccc8150..32ec2d9d858 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -358,7 +358,8 @@ static PSI_thread_info	all_innodb_threads[] = {
 	{&srv_error_monitor_thread_key, "srv_error_monitor_thread", 0},
 	{&srv_monitor_thread_key, "srv_monitor_thread", 0},
 	{&srv_master_thread_key, "srv_master_thread", 0},
-	{&srv_purge_thread_key, "srv_purge_thread", 0}
+	{&srv_purge_thread_key, "srv_purge_thread", 0},
+	{&srv_log_tracking_thread_key, "srv_redo_log_follow_thread", 0}
 };
 # endif /* UNIV_PFS_THREAD */
 
@@ -368,7 +369,8 @@ performance schema instrumented if "UNIV_PFS_IO" is defined */
 static PSI_file_info	all_innodb_files[] = {
 	{&innodb_file_data_key, "innodb_data_file", 0},
 	{&innodb_file_log_key, "innodb_log_file", 0},
-	{&innodb_file_temp_key, "innodb_temp_file", 0}
+	{&innodb_file_temp_key, "innodb_temp_file", 0},
+	{&innodb_file_bmp_key, "innodb_bmp_file", 0}
 };
 # endif /* UNIV_PFS_IO */
 #endif /* HAVE_PSI_INTERFACE */
@@ -12629,9 +12631,9 @@ static MYSQL_SYSVAR_BOOL(use_sys_stats_table, innobase_use_sys_stats_table,
   "So you should use ANALYZE TABLE command intentionally.",
   NULL, NULL, FALSE);
 
-#ifdef UNIV_DEBUG_never
-static MYSQL_SYSVAR_ULONG(sys_stats_root_page, innobase_sys_stats_root_page,
-  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
+#ifdef UNIV_DEBUG
+static MYSQL_SYSVAR_ULONG(persistent_stats_root_page,
+  innobase_sys_stats_root_page, PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
   "Override the SYS_STATS root page id, 0 = no override (for testing only)",
   NULL, NULL, 0, 0, ULONG_MAX, 0);
 #endif
@@ -12834,6 +12836,18 @@ static MYSQL_SYSVAR_ENUM(stats_method, srv_innodb_stats_method,
   "NULLS_UNEQUAL and NULLS_IGNORED",
    NULL, NULL, SRV_STATS_NULLS_EQUAL, &innodb_stats_method_typelib);
 
+static MYSQL_SYSVAR_BOOL(track_changed_pages, srv_track_changed_pages,
+    PLUGIN_VAR_NOCMDARG | PLUGIN_VAR_READONLY,
+    "Track the redo log for changed pages and output a changed page bitmap",
+    NULL, NULL, FALSE);
+
+static MYSQL_SYSVAR_ULONGLONG(changed_pages_limit, srv_changed_pages_limit,
+  PLUGIN_VAR_RQCMDARG,
+  "The maximum number of rows for "
+  "INFORMATION_SCHEMA.INNODB_CHANGED_PAGES table, "
+  "0 - unlimited",
+  NULL, NULL, 1000000, 0, ~0ULL, 0);
+
 #if defined UNIV_DEBUG || defined UNIV_IBUF_DEBUG
 static MYSQL_SYSVAR_UINT(change_buffering_debug, ibuf_debug,
   PLUGIN_VAR_RQCMDARG,
@@ -12998,7 +13012,7 @@ static MYSQL_SYSVAR_UINT(buffer_pool_restore_at_startup, srv_auto_lru_dump,
 
 static MYSQL_SYSVAR_BOOL(blocking_buffer_pool_restore,
   innobase_blocking_lru_restore,
-  PLUGIN_VAR_NOCMDARG | PLUGIN_VAR_READONLY,
+  PLUGIN_VAR_OPCMDARG | PLUGIN_VAR_READONLY,
   "Block XtraDB startup process until buffer pool is full restored from a "
   "dump file (if present). Disabled by default.",
   NULL, NULL, FALSE);
@@ -13085,8 +13099,8 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(stats_auto_update),
   MYSQL_SYSVAR(stats_update_need_lock),
   MYSQL_SYSVAR(use_sys_stats_table),
-#ifdef UNIV_DEBUG_never /* disable this flag. --innodb-sys-stats becomes ambiguous */
-  MYSQL_SYSVAR(sys_stats_root_page),
+#ifdef UNIV_DEBUG
+  MYSQL_SYSVAR(persistent_stats_root_page),
 #endif
   MYSQL_SYSVAR(stats_sample_pages),
   MYSQL_SYSVAR(adaptive_hash_index),
@@ -13118,6 +13132,8 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(use_sys_malloc),
   MYSQL_SYSVAR(use_native_aio),
   MYSQL_SYSVAR(change_buffering),
+  MYSQL_SYSVAR(track_changed_pages),
+  MYSQL_SYSVAR(changed_pages_limit),
 #if defined UNIV_DEBUG || defined UNIV_IBUF_DEBUG
   MYSQL_SYSVAR(change_buffering_debug),
 #endif /* UNIV_DEBUG || UNIV_IBUF_DEBUG */
@@ -13177,10 +13193,10 @@ i_s_innodb_index_stats,
 i_s_innodb_buffer_pool_pages,
 i_s_innodb_buffer_pool_pages_index,
 i_s_innodb_buffer_pool_pages_blob,
-i_s_innodb_admin_command
+i_s_innodb_admin_command,
+i_s_innodb_changed_pages
 maria_declare_plugin_end;
 
-
 /** @brief Initialize the default value of innodb_commit_concurrency.
 
 Once InnoDB is running, the innodb_commit_concurrency must not change
diff --git a/storage/xtradb/handler/i_s.cc b/storage/xtradb/handler/i_s.cc
index 7af0c88c73a..57a091ea80d 100644
--- a/storage/xtradb/handler/i_s.cc
+++ b/storage/xtradb/handler/i_s.cc
@@ -22,6 +22,14 @@ InnoDB INFORMATION SCHEMA tables interface to MySQL.
 
 Created July 18, 2007 Vasil Dimov
 *******************************************************/
+#ifndef MYSQL_SERVER
+#define MYSQL_SERVER /* For Item_* classes */
+#include <item.h>
+/* Prevent influence of this definition to other headers */
+#undef MYSQL_SERVER
+#else
+#include <mysql_priv.h>
+#endif //MYSQL_SERVER
 
 #include <ctype.h> /*toupper*/
 #include <mysqld_error.h>
@@ -45,6 +53,7 @@ extern "C" {
 #include "dict0mem.h"
 #include "dict0types.h"
 #include "ha_prototypes.h" /* for innobase_convert_name() */
+#include "srv0srv.h" /* for srv_track_changed_pages */
 #include "srv0start.h" /* for srv_was_started */
 #include "trx0i_s.h"
 #include "trx0trx.h" /* for TRX_QUE_STATE_STR_MAX_LEN */
@@ -54,6 +63,7 @@ extern "C" {
 #include "dict0dict.h" /* for dict_sys */
 #include "buf0lru.h" /* for XTRA_LRU_[DUMP/RESTORE] */
 #include "btr0btr.h" /* for btr_page_get_index_id */
+#include "log0online.h"
 }
 
 #define OK(expr)		\
@@ -5266,3 +5276,288 @@ UNIV_INTERN struct st_maria_plugin	i_s_innodb_undo_logs =
 
         INNODB_VERSION_STR, MariaDB_PLUGIN_MATURITY_STABLE
 };
+
+static ST_FIELD_INFO	i_s_innodb_changed_pages_info[] =
+{
+	{STRUCT_FLD(field_name,		"space_id"),
+	 STRUCT_FLD(field_length,	MY_INT32_NUM_DECIMAL_DIGITS),
+	 STRUCT_FLD(field_type,		MYSQL_TYPE_LONG),
+	 STRUCT_FLD(value,		0),
+	 STRUCT_FLD(field_flags,	MY_I_S_UNSIGNED),
+	 STRUCT_FLD(old_name,		""),
+	 STRUCT_FLD(open_method,	SKIP_OPEN_TABLE)},
+
+	{STRUCT_FLD(field_name,		"page_id"),
+	 STRUCT_FLD(field_length,	MY_INT32_NUM_DECIMAL_DIGITS),
+	 STRUCT_FLD(field_type,		MYSQL_TYPE_LONG),
+	 STRUCT_FLD(value,		0),
+	 STRUCT_FLD(field_flags,	MY_I_S_UNSIGNED),
+	 STRUCT_FLD(old_name,		""),
+	 STRUCT_FLD(open_method,	SKIP_OPEN_TABLE)},
+
+	{STRUCT_FLD(field_name,		"start_lsn"),
+	 STRUCT_FLD(field_length,	MY_INT64_NUM_DECIMAL_DIGITS),
+	 STRUCT_FLD(field_type,		MYSQL_TYPE_LONGLONG),
+	 STRUCT_FLD(value,		0),
+	 STRUCT_FLD(field_flags,	MY_I_S_UNSIGNED),
+	 STRUCT_FLD(old_name,		""),
+	 STRUCT_FLD(open_method,	SKIP_OPEN_TABLE)},
+
+	{STRUCT_FLD(field_name,		"end_lsn"),
+	 STRUCT_FLD(field_length,	MY_INT64_NUM_DECIMAL_DIGITS),
+	 STRUCT_FLD(field_type,		MYSQL_TYPE_LONGLONG),
+	 STRUCT_FLD(value,		0),
+	 STRUCT_FLD(field_flags,	MY_I_S_UNSIGNED),
+	 STRUCT_FLD(old_name,		""),
+	 STRUCT_FLD(open_method,	SKIP_OPEN_TABLE)},
+
+	END_OF_ST_FIELD_INFO
+};
+
+/***********************************************************************
+  This function parses condition and gets upper bounds for start and end LSN's
+  if condition corresponds to certain pattern.
+
+  We can't know right position to avoid scanning bitmap files from the beginning
+  to the lower bound. But we can stop scanning bitmap files if we reach upper bound.
+
+  It's expected the most used queries will be like the following:
+
+  SELECT * FROM INNODB_CHANGED_PAGES WHERE START_LSN > num1 AND start_lsn < num2;
+
+  That's why the pattern is:
+
+  pattern:  comp | and_comp;
+  comp:     lsn <  int_num | lsn <= int_num | int_num > lsn  | int_num >= lsn;
+  lsn:	    start_lsn | end_lsn;
+  and_comp: some_expression AND some_expression  | some_expression AND and_comp;
+  some_expression: comp	| any_other_expression;
+
+  Suppose the condition is start_lsn < 100, this means we have to read all
+  blocks with start_lsn < 100. Which is equivalent to reading all the blocks
+  with end_lsn <= 99, or just end_lsn < 100. That's why it's enough to find
+  maximum lsn value, doesn't matter if this is start or end lsn and compare
+  it with "start_lsn" field.
+
+  Example:
+
+  SELECT * FROM INNODB_CHANGED_PAGES
+    WHERE
+    start_lsn > 10  AND
+    end_lsn <= 1111 AND
+    555 > end_lsn   AND
+    page_id = 100;
+
+  max_lsn will be set to 555.
+*/
+static
+void
+limit_lsn_range_from_condition(
+/*===========================*/
+	TABLE*		table,   /*!<in: table */
+	COND*		cond,    /*!<in: condition */
+	ib_uint64_t*	max_lsn) /*!<in/out: maximum LSN
+				 (must be initialized with maximum
+				 available value) */
+{
+	if (cond->type() != Item::COND_ITEM &&
+	    cond->type() != Item::FUNC_ITEM)
+		return;
+
+	switch (((Item_func*) cond)->functype())
+	{
+		case Item_func::COND_AND_FUNC:
+		{
+			List_iterator<Item>	li(*((Item_cond*) cond)->
+						   argument_list());
+			Item			*item;
+			while ((item= li++))
+				limit_lsn_range_from_condition(table,
+							       item,
+							       max_lsn);
+			break;
+		}
+		case Item_func::LT_FUNC:
+		case Item_func::LE_FUNC:
+		case Item_func::GT_FUNC:
+		case Item_func::GE_FUNC:
+		{
+			Item			*left;
+			Item			*right;
+			Item_field		*item_field;
+			ib_uint64_t		tmp_result;
+
+			/*
+			   a <= b equals to b >= a that's why we just exchange
+			   "left" and "right" in the case of ">" or ">="
+			   function
+			*/
+			if (((Item_func*) cond)->functype() ==
+				Item_func::LT_FUNC ||
+			    ((Item_func*) cond)->functype() ==
+				Item_func::LE_FUNC)
+			{
+				left = ((Item_func*) cond)->arguments()[0];
+				right = ((Item_func*) cond)->arguments()[1];
+			} else {
+				left = ((Item_func*) cond)->arguments()[1];
+				right = ((Item_func*) cond)->arguments()[0];
+			}
+
+			if (!left || !right)
+				return;
+			if (left->type() != Item::FIELD_ITEM)
+				return;
+			if (right->type() != Item::INT_ITEM)
+				return;
+
+			item_field = (Item_field*)left;
+
+			if (/* START_LSN */
+			    table->field[2] != item_field->field &&
+			    /* END_LSN */
+			    table->field[3] != item_field->field)
+			{
+				return;
+			}
+
+			/* Check if the current field belongs to our table */
+			if (table != item_field->field->table)
+				return;
+
+			tmp_result = right->val_int();
+			if (tmp_result < *max_lsn)
+				*max_lsn = tmp_result;
+
+			break;
+		}
+		default:;
+	}
+
+}
+
+/***********************************************************************
+Fill the dynamic table information_schema.innodb_changed_pages.
+@return 0 on success, 1 on failure */
+static
+int
+i_s_innodb_changed_pages_fill(
+/*==========================*/
+	THD*		thd,	/*!<in: thread */
+	TABLE_LIST*	tables,	/*!<in/out: tables to fill */
+	COND*		cond)	/*!<in: condition */
+{
+	TABLE*			table = (TABLE *) tables->table;
+	log_bitmap_iterator_t	i;
+	ib_uint64_t		output_rows_num = 0UL;
+	ib_uint64_t		max_lsn = ~0ULL;
+
+	if (!srv_track_changed_pages)
+		return 0;
+
+	if (!log_online_bitmap_iterator_init(&i))
+		return 1;
+
+	if (cond)
+		limit_lsn_range_from_condition(table, cond, &max_lsn);
+
+	while(log_online_bitmap_iterator_next(&i) &&
+	      (!srv_changed_pages_limit ||
+	       output_rows_num < srv_changed_pages_limit) &&
+	      /*
+	        There is no need to compare both start LSN and end LSN fields
+	        with maximum value. It's enough to compare only start LSN.
+	        Example:
+
+	                              max_lsn = 100
+	        \\\\\\\\\\\\\\\\\\\\\\\\\|\\\\\\\\        - Query 1
+	        I------I I-------I I-------------I I----I
+		//////////////////       |                - Query 2
+	           1        2             3          4
+
+	        Query 1:
+	        SELECT * FROM INNODB_CHANGED_PAGES WHERE start_lsn < 100
+	        will select 1,2,3 bitmaps
+	        Query 2:
+	        SELECT * FROM INNODB_CHANGED_PAGES WHERE end_lsn < 100
+	        will select 1,2 bitmaps
+
+	        The condition start_lsn <= 100 will be false after reading
+	        1,2,3 bitmaps which suits for both cases.
+	      */
+	      LOG_BITMAP_ITERATOR_START_LSN(i) <= max_lsn)
+	{
+		if (!LOG_BITMAP_ITERATOR_PAGE_CHANGED(i))
+			continue;
+
+		/* SPACE_ID */
+		table->field[0]->store(
+				       LOG_BITMAP_ITERATOR_SPACE_ID(i));
+		/* PAGE_ID */
+		table->field[1]->store(
+				       LOG_BITMAP_ITERATOR_PAGE_NUM(i));
+		/* START_LSN */
+		table->field[2]->store(
+				       LOG_BITMAP_ITERATOR_START_LSN(i));
+		/* END_LSN */
+		table->field[3]->store(
+				       LOG_BITMAP_ITERATOR_END_LSN(i));
+
+		/*
+		  I_S tables are in-memory tables. If bitmap file is big enough
+		  a lot of memory can be used to store the table. But the size
+		  of used memory can be diminished if we store only data which
+		  corresponds to some conditions (in WHERE sql clause). Here
+		  conditions are checked for the field values stored above.
+
+		  Conditions are checked twice. The first is here (during table
+		  generation) and the second during query execution. Maybe it
+		  makes sense to use some flag in THD object to avoid double
+		  checking.
+		*/
+		if (cond && !cond->val_int())
+			continue;
+
+		if (schema_table_store_record(thd, table))
+		{
+			log_online_bitmap_iterator_release(&i);
+			return 1;
+		}
+
+		++output_rows_num;
+	}
+
+	log_online_bitmap_iterator_release(&i);
+	return 0;
+}
+
+static
+int
+i_s_innodb_changed_pages_init(
+/*==========================*/
+	void*	p)
+{
+	DBUG_ENTER("i_s_innodb_changed_pages_init");
+	ST_SCHEMA_TABLE* schema = (ST_SCHEMA_TABLE*) p;
+
+	schema->fields_info = i_s_innodb_changed_pages_info;
+	schema->fill_table = i_s_innodb_changed_pages_fill;
+
+	DBUG_RETURN(0);
+}
+
+UNIV_INTERN struct st_maria_plugin   i_s_innodb_changed_pages =
+{
+	STRUCT_FLD(type, MYSQL_INFORMATION_SCHEMA_PLUGIN),
+	STRUCT_FLD(info, &i_s_info),
+	STRUCT_FLD(name, "INNODB_CHANGED_PAGES"),
+	STRUCT_FLD(author, "Percona"),
+	STRUCT_FLD(descr, "InnoDB CHANGED_PAGES table"),
+	STRUCT_FLD(license, PLUGIN_LICENSE_GPL),
+	STRUCT_FLD(init, i_s_innodb_changed_pages_init),
+	STRUCT_FLD(deinit, i_s_common_deinit),
+	STRUCT_FLD(version, 0x0100 /* 1.0 */),
+	STRUCT_FLD(status_vars, NULL),
+	STRUCT_FLD(system_vars, NULL),
+        INNODB_VERSION_STR, MariaDB_PLUGIN_MATURITY_STABLE
+};
diff --git a/storage/xtradb/handler/i_s.h b/storage/xtradb/handler/i_s.h
index 7e9d47571cc..a8964356747 100644
--- a/storage/xtradb/handler/i_s.h
+++ b/storage/xtradb/handler/i_s.h
@@ -51,5 +51,6 @@ extern struct st_maria_plugin	i_s_innodb_admin_command;
 extern struct st_maria_plugin	i_s_innodb_buffer_pool_pages;
 extern struct st_maria_plugin	i_s_innodb_buffer_pool_pages_index;
 extern struct st_maria_plugin	i_s_innodb_buffer_pool_pages_blob;
+extern struct st_maria_plugin	i_s_innodb_changed_pages;
 
 #endif /* i_s_h */
diff --git a/storage/xtradb/include/buf0lru.h b/storage/xtradb/include/buf0lru.h
index c3672a65ed7..efaa758f27a 100644
--- a/storage/xtradb/include/buf0lru.h
+++ b/storage/xtradb/include/buf0lru.h
@@ -94,13 +94,12 @@ buf_LRU_insert_zip_clean(
 Try to free a block.  If bpage is a descriptor of a compressed-only
 page, the descriptor object will be freed as well.
 
-NOTE: If this function returns TRUE, it will temporarily
-release buf_pool->mutex.  Furthermore, the page frame will no longer be
-accessible via bpage.
+NOTE: This will temporarily release buf_pool_mutex.  Furthermore, the
+page frame will no longer be accessible via bpage.
 
-The caller must hold buf_pool->mutex and buf_page_get_mutex(bpage) and
-release these two mutexes after the call.  No other
-buf_page_get_mutex() may be held when calling this function.
+The caller must hold buf_page_get_mutex(bpage) and release this mutex
+after the call.  No other buf_page_get_mutex() may be held when
+calling this function.
 @return TRUE if freed, FALSE otherwise. */
 UNIV_INTERN
 ibool
diff --git a/storage/xtradb/include/log0log.h b/storage/xtradb/include/log0log.h
index 857ec0946c2..96c4b81695a 100644
--- a/storage/xtradb/include/log0log.h
+++ b/storage/xtradb/include/log0log.h
@@ -977,6 +977,11 @@ struct log_struct{
 					become signaled */
 	/* @} */
 #endif /* UNIV_LOG_ARCHIVE */
+	ib_uint64_t	tracked_lsn;	/*!< log tracking has advanced to this
+					lsn.  Field accessed atomically where
+					64-bit atomic ops are supported,
+					protected by the log sys mutex
+					otherwise. */
 };
 
 /** Test if flush order mutex is owned. */
diff --git a/storage/xtradb/include/log0online.h b/storage/xtradb/include/log0online.h
new file mode 100644
index 00000000000..0e0ca169f6f
--- /dev/null
+++ b/storage/xtradb/include/log0online.h
@@ -0,0 +1,111 @@
+/*****************************************************************************
+
+Copyright (c) 2011-2012, Percona Inc. All Rights Reserved.
+
+This program 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; version 2 of the License.
+
+This program 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
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file include/log0online.h
+Online database log parsing for changed page tracking
+*******************************************************/
+
+#ifndef log0online_h
+#define log0online_h
+
+#include "univ.i"
+#include "os0file.h"
+
+/*********************************************************************//**
+Initializes the online log following subsytem. */
+UNIV_INTERN
+void
+log_online_read_init();
+/*===================*/
+
+/*********************************************************************//**
+Shuts down the online log following subsystem. */
+UNIV_INTERN
+void
+log_online_read_shutdown();
+/*=======================*/
+
+/*********************************************************************//**
+Reads and parses the redo log up to last checkpoint LSN to build the changed
+page bitmap which is then written to disk.  */
+UNIV_INTERN
+void
+log_online_follow_redo_log();
+/*=========================*/
+
+/** The iterator through all bits of changed pages bitmap blocks */
+struct log_bitmap_iterator_struct
+{
+	char		in_name[FN_REFLEN]; /*!< the file name for bitmap
+					    input */
+	os_file_t	in;                 /*!< the bitmap input file */
+	ib_uint64_t	in_offset;          /*!< the next write position in the
+					    bitmap output file */
+	ib_uint32_t	bit_offset;         /*!< bit offset inside of bitmap
+					    block*/
+	ib_uint64_t	start_lsn;          /*!< Start lsn of the block */
+	ib_uint64_t	end_lsn;            /*!< End lsn of the block */
+	ib_uint32_t	space_id;           /*!< Block space id */
+	ib_uint32_t	first_page_id;      /*!< First block page id */
+	ibool		changed;            /*!< true if current page was changed */
+	byte*		page;               /*!< Bitmap block */
+};
+
+typedef struct log_bitmap_iterator_struct log_bitmap_iterator_t;
+
+#define LOG_BITMAP_ITERATOR_START_LSN(i) \
+        ((i).start_lsn)
+#define LOG_BITMAP_ITERATOR_END_LSN(i) \
+        ((i).end_lsn)
+#define LOG_BITMAP_ITERATOR_SPACE_ID(i) \
+        ((i).space_id)
+#define LOG_BITMAP_ITERATOR_PAGE_NUM(i) \
+        ((i).first_page_id + (i).bit_offset)
+#define LOG_BITMAP_ITERATOR_PAGE_CHANGED(i) \
+        ((i).changed)
+
+/*********************************************************************//**
+Initializes log bitmap iterator.
+@return TRUE if the iterator is initialized OK, FALSE otherwise. */
+UNIV_INTERN
+ibool
+log_online_bitmap_iterator_init(
+/*============================*/
+	log_bitmap_iterator_t *i); /*!<in/out:  iterator */
+
+/*********************************************************************//**
+Releases log bitmap iterator. */
+UNIV_INTERN
+void
+log_online_bitmap_iterator_release(
+/*===============================*/
+	log_bitmap_iterator_t *i); /*!<in/out:  iterator */
+
+/*********************************************************************//**
+Iterates through bits of saved bitmap blocks.
+Sequentially reads blocks from bitmap file(s) and interates through
+their bits. Ignores blocks with wrong checksum.
+@return TRUE if iteration is successful, FALSE if all bits are iterated. */
+UNIV_INTERN
+ibool
+log_online_bitmap_iterator_next(
+/*============================*/
+	log_bitmap_iterator_t *i); /*!<in/out: iterator */
+
+#endif
diff --git a/storage/xtradb/include/log0recv.h b/storage/xtradb/include/log0recv.h
index 15065267250..fdffd86e4c4 100644
--- a/storage/xtradb/include/log0recv.h
+++ b/storage/xtradb/include/log0recv.h
@@ -32,6 +32,28 @@ Created 9/20/1997 Heikki Tuuri
 #include "hash0hash.h"
 #include "log0log.h"
 
+/******************************************************//**
+Checks the 4-byte checksum to the trailer checksum field of a log
+block.  We also accept a log block in the old format before
+InnoDB-3.23.52 where the checksum field contains the log block number.
+@return TRUE if ok, or if the log block may be in the format of InnoDB
+version predating 3.23.52 */
+UNIV_INTERN
+ibool
+log_block_checksum_is_ok_or_old_format(
+/*===================================*/
+	const byte*	block);	/*!< in: pointer to a log block */
+
+/*******************************************************//**
+Calculates the new value for lsn when more data is added to the log. */
+UNIV_INTERN
+ib_uint64_t
+recv_calc_lsn_on_data_add(
+/*======================*/
+	ib_uint64_t	lsn,	/*!< in: old lsn */
+	ib_uint64_t	len);	/*!< in: this many bytes of data is
+				added, log block headers not included */
+
 #ifdef UNIV_HOTBACKUP
 extern ibool	recv_replay_file_ops;
 
@@ -182,6 +204,21 @@ UNIV_INTERN
 void
 recv_recovery_rollback_active(void);
 /*===============================*/
+
+/*******************************************************************//**
+Tries to parse a single log record and returns its length.
+@return	length of the record, or 0 if the record was not complete */
+UNIV_INTERN
+ulint
+recv_parse_log_rec(
+/*===============*/
+	byte*	ptr,	/*!< in: pointer to a buffer */
+	byte*	end_ptr,/*!< in: pointer to the buffer end */
+	byte*	type,	/*!< out: type */
+	ulint*	space,	/*!< out: space id */
+	ulint*	page_no,/*!< out: page number */
+	byte**	body);	/*!< out: log record body start */
+
 /*******************************************************//**
 Scans log from a buffer and stores new log data to the parsing buffer.
 Parses and hashes the log records if new data found.  Unless
diff --git a/storage/xtradb/include/os0file.h b/storage/xtradb/include/os0file.h
index 5b1f9339845..4c795d93141 100644
--- a/storage/xtradb/include/os0file.h
+++ b/storage/xtradb/include/os0file.h
@@ -197,6 +197,7 @@ extern ulint	srv_log_block_size;
 extern mysql_pfs_key_t	innodb_file_data_key;
 extern mysql_pfs_key_t	innodb_file_log_key;
 extern mysql_pfs_key_t	innodb_file_temp_key;
+extern mysql_pfs_key_t	innodb_file_bmp_key;
 
 /* Following four macros are instumentations to register
 various file I/O operations with performance schema.
@@ -867,6 +868,14 @@ os_file_set_eof(
 /*============*/
 	FILE*		file);	/*!< in: file to be truncated */
 /***********************************************************************//**
+Truncates a file at the specified position.
+@return TRUE if success */
+UNIV_INTERN
+ibool
+os_file_set_eof_at(
+	os_file_t	file,	/*!< in: handle to a file */
+	ib_uint64_t	new_len);/*!< in: new file length */
+/***********************************************************************//**
 NOTE! Use the corresponding macro os_file_flush(), not directly this function!
 Flushes the write buffers of a given file to the disk.
 @return	TRUE if success */
diff --git a/storage/xtradb/include/os0sync.h b/storage/xtradb/include/os0sync.h
index 6a99c60226b..887a40c64ea 100644
--- a/storage/xtradb/include/os0sync.h
+++ b/storage/xtradb/include/os0sync.h
@@ -265,7 +265,11 @@ Atomic compare-and-swap and increment for InnoDB. */
 
 #if defined(HAVE_IB_GCC_ATOMIC_BUILTINS)
 
-#define HAVE_ATOMIC_BUILTINS
+# define HAVE_ATOMIC_BUILTINS
+
+# ifdef HAVE_IB_GCC_ATOMIC_BUILTINS_64
+#  define HAVE_ATOMIC_BUILTINS_64
+# endif
 
 /**********************************************************//**
 Returns true if swapped, ptr is pointer to target, old_val is value to
@@ -304,6 +308,9 @@ amount of increment. */
 # define os_atomic_increment_ulint(ptr, amount) \
 	os_atomic_increment(ptr, amount)
 
+# define os_atomic_increment_uint64(ptr, amount) \
+	os_atomic_increment(ptr, amount)
+
 /**********************************************************//**
 Returns the old value of *ptr, atomically sets *ptr to new_val */
 
@@ -312,12 +319,13 @@ Returns the old value of *ptr, atomically sets *ptr to new_val */
 
 #elif defined(HAVE_IB_SOLARIS_ATOMICS)
 
-#define HAVE_ATOMIC_BUILTINS
+# define HAVE_ATOMIC_BUILTINS
+# define HAVE_ATOMIC_BUILTINS_64
 
 /* If not compiling with GCC or GCC doesn't support the atomic
 intrinsics and running on Solaris >= 10 use Solaris atomics */
 
-#include <atomic.h>
+# include <atomic.h>
 
 /**********************************************************//**
 Returns true if swapped, ptr is pointer to target, old_val is value to
@@ -357,6 +365,9 @@ amount of increment. */
 # define os_atomic_increment_ulint(ptr, amount) \
 	atomic_add_long_nv(ptr, amount)
 
+# define os_atomic_increment_uint64(ptr, amount) \
+	atomic_add_64_nv(ptr, amount)
+
 /**********************************************************//**
 Returns the old value of *ptr, atomically sets *ptr to new_val */
 
@@ -365,7 +376,11 @@ Returns the old value of *ptr, atomically sets *ptr to new_val */
 
 #elif defined(HAVE_WINDOWS_ATOMICS)
 
-#define HAVE_ATOMIC_BUILTINS
+# define HAVE_ATOMIC_BUILTINS
+
+# ifndef _WIN32
+#  define HAVE_ATOMIC_BUILTINS_64
+# endif
 
 /* On Windows, use Windows atomics / interlocked */
 # ifdef _WIN64
@@ -403,6 +418,11 @@ amount of increment. */
 # define os_atomic_increment_ulint(ptr, amount) \
 	((ulint) (win_xchg_and_add(ptr, amount) + amount))
 
+# define os_atomic_increment_uint64(ptr, amount)		\
+	((ib_uint64_t) (InterlockedExchangeAdd64(		\
+				 (ib_int64_t*) ptr,		\
+				 (ib_int64_t) amount) + amount))
+
 /**********************************************************//**
 Returns the old value of *ptr, atomically sets *ptr to new_val.
 InterlockedExchange() operates on LONG, and the LONG will be
diff --git a/storage/xtradb/include/srv0srv.h b/storage/xtradb/include/srv0srv.h
index a40683e00f1..b8820f1b7c9 100644
--- a/storage/xtradb/include/srv0srv.h
+++ b/storage/xtradb/include/srv0srv.h
@@ -69,6 +69,14 @@ extern os_event_t	srv_error_event;
 /* This event is set at shutdown to wakeup threads from sleep */
 extern os_event_t	srv_shutdown_event;
 
+/* This event is set on checkpoint completion to wake the redo log parser
+thread */
+extern os_event_t	srv_checkpoint_completed_event;
+
+/* This event is set on the online redo log following thread exit to signal
+that the (slow) shutdown may proceed */
+extern os_event_t	srv_redo_log_thread_finished_event;
+
 /* If the last data file is auto-extended, we add this many pages to it
 at a time */
 #define SRV_AUTO_EXTEND_INCREMENT	\
@@ -136,6 +144,11 @@ extern char*	srv_doublewrite_file;
 
 extern ibool	srv_recovery_stats;
 
+extern my_bool	srv_track_changed_pages;
+
+extern
+ulonglong       srv_changed_pages_limit;
+
 extern ibool	srv_auto_extend_last_data_file;
 extern ulint	srv_last_file_size_max;
 extern char**	srv_log_group_home_dirs;
@@ -402,6 +415,7 @@ extern mysql_pfs_key_t	srv_error_monitor_thread_key;
 extern mysql_pfs_key_t	srv_monitor_thread_key;
 extern mysql_pfs_key_t	srv_master_thread_key;
 extern mysql_pfs_key_t	srv_purge_thread_key;
+extern mysql_pfs_key_t	srv_log_tracking_thread_key;
 
 /* This macro register the current thread and its key with performance
 schema */
@@ -697,6 +711,15 @@ srv_LRU_dump_restore_thread(
 	void*	arg);	/*!< in: a dummy parameter required by
 			os_thread_create */
 /******************************************************************//**
+A thread which follows the redo log and outputs the changed page bitmap.
+@return a dummy value */
+UNIV_INTERN
+os_thread_ret_t
+srv_redo_log_follow_thread(
+/*=======================*/
+	void*	arg);	/*!< in: a dummy parameter required by
+			os_thread_create */
+/******************************************************************//**
 Outputs to a file the output of the InnoDB Monitor.
 @return FALSE if not all information printed
 due to failure to obtain necessary mutex */
diff --git a/storage/xtradb/include/univ.i b/storage/xtradb/include/univ.i
index ce59a3f2741..9aee2a0c7f9 100644
--- a/storage/xtradb/include/univ.i
+++ b/storage/xtradb/include/univ.i
@@ -54,7 +54,7 @@ Created 1/20/1994 Heikki Tuuri
 #define INNODB_VERSION_BUGFIX	8
 
 #ifndef PERCONA_INNODB_VERSION
-#define PERCONA_INNODB_VERSION 28.1
+#define PERCONA_INNODB_VERSION 29.0
 #endif
 
 /* The following is the InnoDB version as shown in
diff --git a/storage/xtradb/include/ut0rbt.h b/storage/xtradb/include/ut0rbt.h
index e26b637ae13..cd9df1c1a3d 100644
--- a/storage/xtradb/include/ut0rbt.h
+++ b/storage/xtradb/include/ut0rbt.h
@@ -116,6 +116,10 @@ struct ib_rbt_bound_struct {
 /* Compare a key with the node value (t is tree, k is key, n is node)*/
 #define rbt_compare(t, k, n) (t->compare(k, n->value))
 
+/* Node size. FIXME: name might clash, but currently it does not, so for easier
+   maintenance do not rename it for now. */
+#define	SIZEOF_NODE(t)	((sizeof(ib_rbt_node_t) + t->sizeof_value) - 1)
+
 /**********************************************************************//**
 Free an instance of  a red black tree */
 UNIV_INTERN
@@ -187,6 +191,17 @@ rbt_add_node(
 	ib_rbt_bound_t*	parent,			/*!< in: parent */
 	const void*	value);			/*!< in: this value is copied
 						to the node */
+/****************************************************************//**
+Add a new caller-provided node to tree at the specified position.
+The node must have its key fields initialized correctly.
+@return added node */
+UNIV_INTERN
+const ib_rbt_node_t*
+rbt_add_preallocated_node(
+/*======================*/
+	ib_rbt_t*	tree,			/*!< in: rb tree */
+	ib_rbt_bound_t*	parent,			/*!< in: parent */
+	ib_rbt_node_t*	node);			/*!< in: node */
 /**********************************************************************//**
 Return the left most data node in the tree
 @return	left most node */
@@ -273,6 +288,13 @@ void
 rbt_clear(
 /*======*/
 	ib_rbt_t*	tree);			/*!< in: rb tree */
+/****************************************************************//**
+Clear the tree without deleting and freeing its nodes. */
+UNIV_INTERN
+void
+rbt_reset(
+/*======*/
+	ib_rbt_t*	tree);			/*!< in: rb tree */
 /**********************************************************************//**
 Merge the node from dst into src. Return the number of nodes merged.
 @return	no. of recs merged */
diff --git a/storage/xtradb/log/log0log.c b/storage/xtradb/log/log0log.c
index dcaf951a0ed..e3e023c0c5a 100644
--- a/storage/xtradb/log/log0log.c
+++ b/storage/xtradb/log/log0log.c
@@ -216,6 +216,54 @@ log_buf_pool_get_oldest_modification(void)
 	return(lsn);
 }
 
+/****************************************************************//**
+Safely reads the log_sys->tracked_lsn value.  Uses atomic operations
+if available, otherwise this field is protected with the log system
+mutex.  The writer counterpart function is log_set_tracked_lsn() in
+log0online.c.
+
+@return log_sys->tracked_lsn value. */
+UNIV_INLINE
+ib_uint64_t
+log_get_tracked_lsn()
+{
+#ifdef HAVE_ATOMIC_BUILTINS_64
+	return os_atomic_increment_uint64(&log_sys->tracked_lsn, 0);
+#else
+	ut_ad(mutex_own(&(log_sys->mutex)));
+	return log_sys->tracked_lsn;
+#endif
+}
+
+/****************************************************************//**
+Checks if the log groups have a big enough margin of free space in
+so that a new log entry can be written without overwriting log data
+that is not read by the changed page bitmap thread.
+@return TRUE if there is not enough free space. */
+static
+ibool
+log_check_tracking_margin(
+	ulint	lsn_advance)	/*!< in: an upper limit on how much log data we
+				plan to write.  If zero, the margin will be
+				checked for the already-written log. */
+{
+	ib_uint64_t	tracked_lsn;
+	ulint		tracked_lsn_age;
+
+	if (!srv_track_changed_pages) {
+		return FALSE;
+	}
+
+	ut_ad(mutex_own(&(log_sys->mutex)));
+
+	tracked_lsn = log_get_tracked_lsn();
+	tracked_lsn_age = log_sys->lsn - tracked_lsn;
+
+	/* The overwrite would happen when log_sys->log_group_capacity is
+	exceeded, but we use max_checkpoint_age for an extra safety margin. */
+	return tracked_lsn_age + lsn_advance > log_sys->max_checkpoint_age;
+}
+
 /************************************************************//**
 Opens the log for log_write_low. The log must be closed with log_close and
 released with log_release.
@@ -232,9 +280,7 @@ log_reserve_and_open(
 	ulint	archived_lsn_age;
 	ulint	dummy;
 #endif /* UNIV_LOG_ARCHIVE */
-#ifdef UNIV_DEBUG
 	ulint	count			= 0;
-#endif /* UNIV_DEBUG */
 
 	ut_a(len < log->buf_size / 2);
 loop:
@@ -262,6 +308,19 @@ loop:
 		goto loop;
 	}
 
+	if (log_check_tracking_margin(len_upper_limit) && (++count < 50)) {
+
+		/* This log write would violate the untracked LSN free space
+		margin.  Limit this to 50 retries as there might be situations
+		where we have no choice but to proceed anyway, i.e. if the log
+		is about to be overflown, log tracking or not. */
+		mutex_exit(&(log->mutex));
+
+		os_thread_sleep(10000);
+
+		goto loop;
+	}
+
 #ifdef UNIV_LOG_ARCHIVE
 	if (log->archiving_state != LOG_ARCH_OFF) {
 
@@ -400,6 +459,8 @@ log_close(void)
 	ulint		first_rec_group;
 	ib_uint64_t	oldest_lsn;
 	ib_uint64_t	lsn;
+	ib_uint64_t	tracked_lsn;
+	ulint		tracked_lsn_age;
 	log_t*		log	= log_sys;
 	ib_uint64_t	checkpoint_age;
 
@@ -426,6 +487,19 @@ log_close(void)
 		log->check_flush_or_checkpoint = TRUE;
 	}
 
+	if (srv_track_changed_pages) {
+
+		tracked_lsn = log_get_tracked_lsn();
+		tracked_lsn_age = lsn - tracked_lsn;
+
+		if (tracked_lsn_age >= log->log_group_capacity) {
+
+			fprintf(stderr, " InnoDB: Error: the age of the "
+				"oldest untracked record exceeds the log "
+				"group capacity!\n");
+		}
+	}
+
 	checkpoint_age = lsn - log->last_checkpoint_lsn;
 
 	if (checkpoint_age >= log->log_group_capacity) {
@@ -893,6 +967,8 @@ log_init(void)
 	log_sys->archiving_on = os_event_create(NULL);
 #endif /* UNIV_LOG_ARCHIVE */
 
+	log_sys->tracked_lsn = 0;
+
 	/*----------------------------*/
 
 	log_block_init(log_sys->buf, log_sys->lsn);
@@ -1742,6 +1818,12 @@ log_io_complete_checkpoint(void)
 	}
 
 	mutex_exit(&(log_sys->mutex));
+
+	/* Wake the redo log watching thread to parse the log up to this
+	checkpoint. */
+	if (srv_track_changed_pages) {
+		os_event_set(srv_checkpoint_completed_event);
+	}
 }
 
 /*******************************************************************//**
@@ -3169,6 +3251,15 @@ loop:
 
 	log_checkpoint_margin();
 
+	mutex_enter(&(log_sys->mutex));
+	if (log_check_tracking_margin(0)) {
+
+		mutex_exit(&(log_sys->mutex));
+		os_thread_sleep(10000);
+		goto loop;
+	}
+	mutex_exit(&(log_sys->mutex));
+
 #ifdef UNIV_LOG_ARCHIVE
 	log_archive_margin();
 #endif /* UNIV_LOG_ARCHIVE */
@@ -3197,6 +3288,7 @@ logs_empty_and_mark_files_at_shutdown(void)
 /*=======================================*/
 {
 	ib_uint64_t		lsn;
+	ib_uint64_t		tracked_lsn;
 	ulint			arch_log_no;
 	ibool			server_busy;
 	ulint			count = 0;
@@ -3388,6 +3480,12 @@ loop:
 		}
 
 		srv_shutdown_state = SRV_SHUTDOWN_LAST_PHASE;
+		/* Wake the log tracking thread which will then immediatelly
+		quit because of srv_shutdown_state value */
+		if (srv_track_changed_pages) {
+			os_event_set(srv_checkpoint_completed_event);
+			os_event_wait(srv_redo_log_thread_finished_event);
+		}
 		fil_close_all_files();
 		ut_a(srv_get_active_thread_type() == ULINT_UNDEFINED);
 		return;
@@ -3397,9 +3495,12 @@ loop:
 
 	mutex_enter(&log_sys->mutex);
 
+	tracked_lsn = log_get_tracked_lsn();
+
 	lsn = log_sys->lsn;
 
 	if (lsn != log_sys->last_checkpoint_lsn
+	    || (srv_track_changed_pages	&& (tracked_lsn != log_sys->last_checkpoint_lsn))
 #ifdef UNIV_LOG_ARCHIVE
 	    || (srv_log_archive_on
 		&& lsn != log_sys->archived_lsn + LOG_BLOCK_HDR_SIZE)
@@ -3457,6 +3558,11 @@ loop:
 
 	srv_shutdown_state = SRV_SHUTDOWN_LAST_PHASE;
 
+	/* Signal the log following thread to quit */
+	if (srv_track_changed_pages) {
+		os_event_set(srv_checkpoint_completed_event);
+	}
+
 	/* Make some checks that the server really is quiet */
 	ut_a(srv_get_active_thread_type() == ULINT_UNDEFINED);
 
@@ -3477,6 +3583,10 @@ loop:
 
 	fil_flush_file_spaces(FIL_TABLESPACE);
 
+	if (srv_track_changed_pages) {
+		os_event_wait(srv_redo_log_thread_finished_event);
+	}
+
 	fil_close_all_files();
 
 	/* Make some checks that the server really is quiet */
@@ -3603,6 +3713,18 @@ log_print(
 		((log_sys->n_log_ios - log_sys->n_log_ios_old)
 		 / time_elapsed));
 
+	if (srv_track_changed_pages) {
+
+		/* The maximum tracked LSN age is equal to the maximum
+		checkpoint age */
+		fprintf(file,
+			"Log tracking enabled\n"
+			"Log tracked up to   %llu\n"
+			"Max tracked LSN age %lu\n",
+			log_get_tracked_lsn(),
+			log_sys->max_checkpoint_age);
+	}
+
 	log_sys->n_log_ios_old = log_sys->n_log_ios;
 	log_sys->last_printout_time = current_time;
 
diff --git a/storage/xtradb/log/log0online.c b/storage/xtradb/log/log0online.c
new file mode 100644
index 00000000000..1d478c467e6
--- /dev/null
+++ b/storage/xtradb/log/log0online.c
@@ -0,0 +1,1085 @@
+/*****************************************************************************
+
+Copyright (c) 2011-2012 Percona Inc. All Rights Reserved.
+
+This program 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; version 2 of the License.
+
+This program 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
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+
+*****************************************************************************/
+
+/**************************************************//**
+@file log/log0online.c
+Online database log parsing for changed page tracking
+
+*******************************************************/
+
+#include "log0online.h"
+
+#include "my_dbug.h"
+
+#include "log0recv.h"
+#include "mach0data.h"
+#include "mtr0log.h"
+#include "srv0srv.h"
+#include "srv0start.h"
+#include "trx0sys.h"
+#include "ut0rbt.h"
+
+enum { FOLLOW_SCAN_SIZE = 4 * (UNIV_PAGE_SIZE_MAX) };
+
+/** Log parsing and bitmap output data structure */
+struct log_bitmap_struct {
+	byte		read_buf[FOLLOW_SCAN_SIZE];
+					/*!< log read buffer */
+	byte		parse_buf[RECV_PARSING_BUF_SIZE];
+					/*!< log parse buffer */
+	byte*		parse_buf_end;  /*!< parse buffer position where the
+					next read log data should be copied to.
+					If the previous log records were fully
+					parsed, it points to the start,
+					otherwise points immediatelly past the
+					end of the incomplete log record. */
+	char*		out_name;	/*!< the file name for bitmap output */
+	os_file_t	out;		/*!< the bitmap output file */
+	ib_uint64_t	out_offset;	/*!< the next write position in the
+					bitmap output file */
+	ib_uint64_t	start_lsn;	/*!< the LSN of the next unparsed
+					record and the start of the next LSN
+					interval to be parsed.  */
+	ib_uint64_t	end_lsn;	/*!< the end of the LSN interval to be
+					parsed, equal to the next checkpoint
+					LSN at the time of parse */
+	ib_uint64_t	next_parse_lsn;	/*!< the LSN of the next unparsed
+					record in the current parse */
+	ib_rbt_t*	modified_pages; /*!< the current modified page set,
+					organized as the RB-tree with the keys
+					of (space, 4KB-block-start-page-id)
+					pairs */
+	ib_rbt_node_t*	page_free_list; /*!< Singly-linked list of freed nodes
+					of modified_pages tree for later
+					reuse.  Nodes are linked through
+					ib_rbt_node_t.left as this field has
+					both the correct type and the tree does
+					not mind its overwrite during
+					rbt_next() tree traversal. */
+};
+
+/* The log parsing and bitmap output struct instance */
+static struct log_bitmap_struct* log_bmp_sys;
+
+/* File name stem for modified page bitmaps */
+static const char* modified_page_stem = "ib_modified_log.";
+
+/* On server startup with empty database srv_start_lsn == 0, in
+which case the first LSN of actual log records will be this. */
+#define MIN_TRACKED_LSN ((LOG_START_LSN) + (LOG_BLOCK_HDR_SIZE))
+
+/* Tests if num bit of bitmap is set */
+#define IS_BIT_SET(bitmap, num) \
+        (*((bitmap) + ((num) >> 3)) & (1UL << ((num) & 7UL)))
+
+/** The bitmap file block size in bytes.  All writes will be multiples of this.
+ */
+enum {
+	MODIFIED_PAGE_BLOCK_SIZE = 4096
+};
+
+
+/** Offsets in a file bitmap block */
+enum {
+	MODIFIED_PAGE_IS_LAST_BLOCK = 0,/* 1 if last block in the current
+					write, 0 otherwise. */
+	MODIFIED_PAGE_START_LSN = 4,	/* The starting tracked LSN of this and
+					other blocks in the same write */
+	MODIFIED_PAGE_END_LSN = 12,	/* The ending tracked LSN of this and
+					other blocks in the same write */
+	MODIFIED_PAGE_SPACE_ID = 20,	/* The space ID of tracked pages in
+					this block */
+	MODIFIED_PAGE_1ST_PAGE_ID = 24,	/* The page ID of the first tracked
+					page in this block */
+	MODIFIED_PAGE_BLOCK_UNUSED_1 = 28,/* Unused in order to align the start
+					of bitmap at 8 byte boundary */
+	MODIFIED_PAGE_BLOCK_BITMAP = 32,/* Start of the bitmap itself */
+	MODIFIED_PAGE_BLOCK_UNUSED_2 = MODIFIED_PAGE_BLOCK_SIZE - 8,
+					/* Unused in order to align the end of
+					bitmap at 8 byte boundary */
+	MODIFIED_PAGE_BLOCK_CHECKSUM = MODIFIED_PAGE_BLOCK_SIZE - 4
+					/* The checksum of the current block */
+};
+
+/** Length of the bitmap data in a block in bytes */
+enum { MODIFIED_PAGE_BLOCK_BITMAP_LEN
+       = MODIFIED_PAGE_BLOCK_UNUSED_2 - MODIFIED_PAGE_BLOCK_BITMAP };
+
+/** Length of the bitmap data in a block in page ids */
+enum { MODIFIED_PAGE_BLOCK_ID_COUNT = MODIFIED_PAGE_BLOCK_BITMAP_LEN * 8 };
+
+/****************************************************************//**
+Provide a comparisson function for the RB-tree tree (space,
+block_start_page) pairs.  Actual implementation does not matter as
+long as the ordering is full.
+@return -1 if p1 < p2, 0 if p1 == p2, 1 if p1 > p2
+*/
+static
+int
+log_online_compare_bmp_keys(
+/*========================*/
+	const void* p1,	/*!<in: 1st key to compare */
+	const void* p2)	/*!<in: 2nd key to compare */
+{
+	const byte *k1 = (const byte *)p1;
+	const byte *k2 = (const byte *)p2;
+
+	ulint k1_space = mach_read_from_4(k1 + MODIFIED_PAGE_SPACE_ID);
+	ulint k2_space = mach_read_from_4(k2 + MODIFIED_PAGE_SPACE_ID);
+	if (k1_space == k2_space) {
+		ulint k1_start_page
+			= mach_read_from_4(k1 + MODIFIED_PAGE_1ST_PAGE_ID);
+		ulint k2_start_page
+			= mach_read_from_4(k2 + MODIFIED_PAGE_1ST_PAGE_ID);
+		return k1_start_page < k2_start_page
+			? -1 : k1_start_page > k2_start_page ? 1 : 0;
+	}
+	return k1_space < k2_space ? -1 : 1;
+}
+
+/****************************************************************//**
+Set a bit for tracked page in the bitmap. Expand the bitmap tree as
+necessary. */
+static
+void
+log_online_set_page_bit(
+/*====================*/
+	ulint	space,	/*!<in: log record space id */
+	ulint	page_no)/*!<in: log record page id */
+{
+	ulint		block_start_page;
+	ulint		block_pos;
+	uint		bit_pos;
+	ib_rbt_bound_t	tree_search_pos;
+	byte		search_page[MODIFIED_PAGE_BLOCK_SIZE];
+	byte		*page_ptr;
+
+	ut_a(space != ULINT_UNDEFINED);
+	ut_a(page_no != ULINT_UNDEFINED);
+
+	block_start_page = page_no / MODIFIED_PAGE_BLOCK_ID_COUNT
+		* MODIFIED_PAGE_BLOCK_ID_COUNT;
+	block_pos = block_start_page ? (page_no % block_start_page / 8)
+		: (page_no / 8);
+	bit_pos = page_no % 8;
+
+	mach_write_to_4(search_page + MODIFIED_PAGE_SPACE_ID, space);
+	mach_write_to_4(search_page + MODIFIED_PAGE_1ST_PAGE_ID,
+			block_start_page);
+
+	if (!rbt_search(log_bmp_sys->modified_pages, &tree_search_pos,
+			search_page)) {
+		page_ptr = rbt_value(byte, tree_search_pos.last);
+	}
+	else {
+		ib_rbt_node_t *new_node;
+
+		if (log_bmp_sys->page_free_list) {
+			new_node = log_bmp_sys->page_free_list;
+			log_bmp_sys->page_free_list = new_node->left;
+		}
+		else {
+			new_node = ut_malloc(SIZEOF_NODE(
+				  log_bmp_sys->modified_pages));
+		}
+		memset(new_node, 0, SIZEOF_NODE(log_bmp_sys->modified_pages));
+
+		page_ptr = rbt_value(byte, new_node);
+		mach_write_to_4(page_ptr + MODIFIED_PAGE_SPACE_ID, space);
+		mach_write_to_4(page_ptr + MODIFIED_PAGE_1ST_PAGE_ID,
+				block_start_page);
+
+		rbt_add_preallocated_node(log_bmp_sys->modified_pages,
+					  &tree_search_pos, new_node);
+	}
+	page_ptr[MODIFIED_PAGE_BLOCK_BITMAP + block_pos] |= (1U << bit_pos);
+}
+
+/****************************************************************//**
+Calculate a bitmap block checksum.  Algorithm borrowed from
+log_block_calc_checksum.
+@return checksum */
+UNIV_INLINE
+ulint
+log_online_calc_checksum(
+/*=====================*/
+	const byte*	block)	/*!<in: bitmap block */
+{
+	ulint	sum;
+	ulint	sh;
+	ulint	i;
+
+	sum = 1;
+	sh = 0;
+
+	for (i = 0; i < MODIFIED_PAGE_BLOCK_CHECKSUM; i++) {
+
+		ulint	b = block[i];
+		sum &= 0x7FFFFFFFUL;
+		sum += b;
+		sum += b << sh;
+		sh++;
+		if (sh > 24) {
+			sh = 0;
+		}
+	}
+
+	return sum;
+}
+
+/****************************************************************//**
+Get the last tracked fully LSN from the bitmap file by reading
+backwards untile a correct end page is found.  Detects incomplete
+writes and corrupted data.  Sets the start output position for the
+written bitmap data.
+@return the last fully tracked LSN */
+static
+ib_uint64_t
+log_online_read_last_tracked_lsn()
+/*==============================*/
+{
+	byte		page[MODIFIED_PAGE_BLOCK_SIZE];
+	ib_uint64_t	read_offset	= log_bmp_sys->out_offset;
+	/* Initialize these to nonequal values so that file size == 0 case with
+	zero loop repetitions is handled correctly */
+	ulint		checksum	= 0;
+	ulint		actual_checksum = !checksum;
+	ibool		is_last_page	= FALSE;
+	ib_uint64_t	result;
+
+	ut_ad(log_bmp_sys->out_offset % MODIFIED_PAGE_BLOCK_SIZE == 0);
+
+	while (checksum != actual_checksum && read_offset > 0 && !is_last_page)
+	{
+
+		ulint		offset_low, offset_high;
+		ibool		success;
+
+		read_offset -= MODIFIED_PAGE_BLOCK_SIZE;
+		offset_high = (ulint)(read_offset >> 32);
+		offset_low = (ulint)(read_offset & 0xFFFFFFFF);
+
+		success = os_file_read(log_bmp_sys->out, page, offset_low,
+				       offset_high, MODIFIED_PAGE_BLOCK_SIZE);
+		if (!success) {
+
+			/* The following call prints an error message */
+			os_file_get_last_error(TRUE);
+			/* Here and below assume that bitmap file names do not
+			contain apostrophes, thus no need for
+			ut_print_filename(). */
+			fprintf(stderr, "InnoDB: Warning: failed reading "
+				"changed page bitmap file \'%s\'\n",
+				log_bmp_sys->out_name);
+			return MIN_TRACKED_LSN;
+		}
+
+		is_last_page
+			= mach_read_from_4(page + MODIFIED_PAGE_IS_LAST_BLOCK);
+		checksum = mach_read_from_4(page
+					    + MODIFIED_PAGE_BLOCK_CHECKSUM);
+		actual_checksum = log_online_calc_checksum(page);
+		if (checksum != actual_checksum) {
+
+			fprintf(stderr, "InnoDB: Warning: corruption "
+				"detected in \'%s\' at offset %llu\n",
+				log_bmp_sys->out_name, read_offset);
+		}
+
+	};
+
+	if (UNIV_LIKELY(checksum == actual_checksum && is_last_page)) {
+
+		log_bmp_sys->out_offset = read_offset
+			+ MODIFIED_PAGE_BLOCK_SIZE;
+		result = mach_read_from_8(page + MODIFIED_PAGE_END_LSN);
+	}
+	else {
+		log_bmp_sys->out_offset = read_offset;
+		result = 0;
+	}
+
+	/* Truncate the output file to discard the corrupted bitmap data, if
+	any */
+	if (!os_file_set_eof_at(log_bmp_sys->out,
+				log_bmp_sys->out_offset)) {
+		fprintf(stderr, "InnoDB: Warning: failed truncating "
+			"changed page bitmap file \'%s\' to %llu bytes\n",
+			log_bmp_sys->out_name, log_bmp_sys->out_offset);
+		result = 0;
+	}
+	return result;
+}
+
+/****************************************************************//**
+Safely write the log_sys->tracked_lsn value.  Uses atomic operations
+if available, otherwise this field is protected with the log system
+mutex.  The reader counterpart function is log_get_tracked_lsn() in
+log0log.c. */
+UNIV_INLINE
+void
+log_set_tracked_lsn(
+/*================*/
+	ib_uint64_t	tracked_lsn)	/*!<in: new value */
+{
+#ifdef HAVE_ATOMIC_BUILTINS_64
+	/* Single writer, no data race here */
+	ib_uint64_t old_value
+		= os_atomic_increment_uint64(&log_sys->tracked_lsn, 0);
+	(void) os_atomic_increment_uint64(&log_sys->tracked_lsn,
+					  tracked_lsn - old_value);
+#else
+	mutex_enter(&log_sys->mutex);
+	log_sys->tracked_lsn = tracked_lsn;
+	mutex_exit(&log_sys->mutex);
+#endif
+}
+
+/****************************************************************//**
+Diagnose a gap in tracked LSN range on server startup due to crash or
+very fast shutdown and try to close it by tracking the data
+immediatelly, if possible. */
+static
+void
+log_online_track_missing_on_startup(
+/*================================*/
+	ib_uint64_t	last_tracked_lsn,	/*!<in: last tracked LSN read
+						from the bitmap file */
+	ib_uint64_t	tracking_start_lsn)	/*!<in: last checkpoint LSN of
+						the current server startup */
+{
+	ut_ad(last_tracked_lsn != tracking_start_lsn);
+
+	fprintf(stderr, "InnoDB: last tracked LSN in \'%s\' is %llu, but "
+		"last checkpoint LSN is %llu.  This might be due to a server "
+		"crash or a very fast shutdown.  ", log_bmp_sys->out_name,
+		last_tracked_lsn, tracking_start_lsn);
+
+	/* last_tracked_lsn might be < MIN_TRACKED_LSN in the case of empty
+	   bitmap file, handle this too. */
+	last_tracked_lsn = ut_max(last_tracked_lsn, MIN_TRACKED_LSN);
+
+	/* See if we can fully recover the missing interval */
+	if (log_sys->lsn - last_tracked_lsn < log_sys->log_group_capacity) {
+
+		fprintf(stderr,
+			"Reading the log to advance the last tracked LSN.\n");
+
+		log_bmp_sys->start_lsn = last_tracked_lsn;
+		log_set_tracked_lsn(log_bmp_sys->start_lsn);
+		log_online_follow_redo_log();
+		ut_ad(log_bmp_sys->end_lsn >= tracking_start_lsn);
+
+		fprintf(stderr,
+			"InnoDB: continuing tracking changed pages from LSN "
+			"%llu\n", log_bmp_sys->end_lsn);
+	}
+	else {
+		fprintf(stderr,
+			"The age of last tracked LSN exceeds log capacity, "
+			"tracking-based incremental backups will work only "
+			"from the higher LSN!\n");
+
+		log_bmp_sys->end_lsn = log_bmp_sys->start_lsn
+			= tracking_start_lsn;
+		log_set_tracked_lsn(log_bmp_sys->start_lsn);
+
+		fprintf(stderr,
+			"InnoDB: starting tracking changed pages from LSN "
+			"%llu\n", log_bmp_sys->end_lsn);
+	}
+}
+
+/*********************************************************************//**
+Initialize the online log following subsytem. */
+UNIV_INTERN
+void
+log_online_read_init()
+/*==================*/
+{
+	char		buf[FN_REFLEN];
+	ibool		success;
+	ib_uint64_t	tracking_start_lsn
+		= ut_max(log_sys->last_checkpoint_lsn, MIN_TRACKED_LSN);
+
+	/* Assert (could be compile-time assert) that bitmap data start and end
+	in a bitmap block is 8-byte aligned */
+	ut_a(MODIFIED_PAGE_BLOCK_BITMAP % 8 == 0);
+	ut_a(MODIFIED_PAGE_BLOCK_BITMAP_LEN % 8 == 0);
+
+	log_bmp_sys = ut_malloc(sizeof(*log_bmp_sys));
+
+	ut_snprintf(buf, FN_REFLEN, "%s%s%d", srv_data_home,
+		    modified_page_stem, 1);
+	log_bmp_sys->out_name = ut_malloc(strlen(buf) + 1);
+	ut_strcpy(log_bmp_sys->out_name, buf);
+
+	log_bmp_sys->modified_pages = rbt_create(MODIFIED_PAGE_BLOCK_SIZE,
+						 log_online_compare_bmp_keys);
+	log_bmp_sys->page_free_list = NULL;
+
+	log_bmp_sys->out
+		= os_file_create_simple_no_error_handling
+		(innodb_file_bmp_key, log_bmp_sys->out_name, OS_FILE_OPEN,
+		 OS_FILE_READ_WRITE, &success);
+
+	if (!success) {
+
+		/* New file, tracking from scratch */
+		log_bmp_sys->out
+			= os_file_create_simple_no_error_handling
+			(innodb_file_bmp_key, log_bmp_sys->out_name,
+			 OS_FILE_CREATE, OS_FILE_READ_WRITE, &success);
+		if (!success) {
+
+			/* The following call prints an error message */
+			os_file_get_last_error(TRUE);
+			fprintf(stderr,
+				"InnoDB: Error: Cannot create \'%s\'\n",
+				log_bmp_sys->out_name);
+			exit(1);
+		}
+
+		log_bmp_sys->out_offset = 0;
+	}
+	else {
+
+		/* Old file, read last tracked LSN and continue from there */
+		ulint		size_low;
+		ulint		size_high;
+		ib_uint64_t	last_tracked_lsn;
+
+		success = os_file_get_size(log_bmp_sys->out, &size_low,
+					   &size_high);
+		ut_a(success);
+
+		log_bmp_sys->out_offset
+			= ((ib_uint64_t)size_high << 32) | size_low;
+
+		if (log_bmp_sys->out_offset % MODIFIED_PAGE_BLOCK_SIZE != 0) {
+
+			fprintf(stderr,
+				"InnoDB: Warning: truncated block detected "
+				"in \'%s\' at offset %llu\n",
+				log_bmp_sys->out_name,
+				log_bmp_sys->out_offset);
+			log_bmp_sys->out_offset -=
+				log_bmp_sys->out_offset
+				% MODIFIED_PAGE_BLOCK_SIZE;
+		}
+
+		last_tracked_lsn = log_online_read_last_tracked_lsn();
+
+		if (last_tracked_lsn < tracking_start_lsn) {
+
+			log_online_track_missing_on_startup(last_tracked_lsn,
+							    tracking_start_lsn);
+			return;
+		}
+
+		if (last_tracked_lsn > tracking_start_lsn) {
+
+			fprintf(stderr, "InnoDB: last tracked LSN in \'%s\' "
+				"is %llu, but last checkpoint LSN is %llu. "
+				"The tracking-based incremental backups will "
+				"work only from the latter LSN!\n",
+				log_bmp_sys->out_name, last_tracked_lsn,
+				tracking_start_lsn);
+		}
+
+	}
+
+	fprintf(stderr, "InnoDB: starting tracking changed pages from "
+		"LSN %llu\n", tracking_start_lsn);
+	log_bmp_sys->start_lsn = tracking_start_lsn;
+	log_set_tracked_lsn(tracking_start_lsn);
+}
+
+/*********************************************************************//**
+Shut down the online log following subsystem. */
+UNIV_INTERN
+void
+log_online_read_shutdown()
+/*======================*/
+{
+	ib_rbt_node_t *free_list_node = log_bmp_sys->page_free_list;
+
+	os_file_close(log_bmp_sys->out);
+
+	rbt_free(log_bmp_sys->modified_pages);
+
+	while (free_list_node) {
+		ib_rbt_node_t *next = free_list_node->left;
+		ut_free(free_list_node);
+		free_list_node = next;
+	}
+
+	ut_free(log_bmp_sys->out_name);
+	ut_free(log_bmp_sys);
+}
+
+/*********************************************************************//**
+For the given minilog record type determine if the record has (space; page)
+associated with it.
+@return TRUE if the record has (space; page) in it */
+static
+ibool
+log_online_rec_has_page(
+/*====================*/
+	byte	type)	/*!<in: the minilog record type */
+{
+	return type != MLOG_MULTI_REC_END && type != MLOG_DUMMY_RECORD;
+}
+
+/*********************************************************************//**
+Check if a page field for a given log record type actually contains a page
+id. It does not for file operations and MLOG_LSN.
+@return TRUE if page field contains actual page id, FALSE otherwise */
+static
+ibool
+log_online_rec_page_means_page(
+/*===========================*/
+	byte	type)	/*!<in: log record type */
+{
+	return log_online_rec_has_page(type)
+#ifdef UNIV_LOG_LSN_DEBUG
+		&& type != MLOG_LSN
+#endif
+		&& type != MLOG_FILE_CREATE
+		&& type != MLOG_FILE_RENAME
+		&& type != MLOG_FILE_DELETE
+		&& type != MLOG_FILE_CREATE2;
+}
+
+/*********************************************************************//**
+Parse the log data in the parse buffer for the (space, page) pairs and add
+them to the modified page set as necessary.  Removes the fully-parsed records
+from the buffer.  If an incomplete record is found, moves it to the end of the
+buffer. */
+static
+void
+log_online_parse_redo_log()
+/*=======================*/
+{
+	byte *ptr = log_bmp_sys->parse_buf;
+	byte *end = log_bmp_sys->parse_buf_end;
+
+	ulint len = 0;
+
+	while (ptr != end
+	       && log_bmp_sys->next_parse_lsn < log_bmp_sys->end_lsn) {
+
+		byte	type;
+		ulint	space;
+		ulint	page_no;
+		byte*	body;
+
+		/* recv_sys is not initialized, so on corrupt log we will
+		SIGSEGV.  But the log of a live database should not be
+		corrupt. */
+		len = recv_parse_log_rec(ptr, end, &type, &space, &page_no,
+					 &body);
+		if (len > 0) {
+
+			if (log_online_rec_page_means_page(type)
+			    && (space != TRX_DOUBLEWRITE_SPACE)) {
+
+				ut_a(len >= 3);
+				log_online_set_page_bit(space, page_no);
+			}
+
+			ptr += len;
+			ut_ad(ptr <= end);
+			log_bmp_sys->next_parse_lsn
+			    = recv_calc_lsn_on_data_add
+				(log_bmp_sys->next_parse_lsn, len);
+		}
+		else {
+
+			/* Incomplete log record.  Shift it to the
+			beginning of the parse buffer and leave it to be
+			completed on the next read.  */
+			ut_memmove(log_bmp_sys->parse_buf, ptr, end - ptr);
+			log_bmp_sys->parse_buf_end
+				= log_bmp_sys->parse_buf + (end - ptr);
+			ptr = end;
+		}
+	}
+
+	if (len > 0) {
+
+		log_bmp_sys->parse_buf_end = log_bmp_sys->parse_buf;
+	}
+}
+
+/*********************************************************************//**
+Check the log block checksum.
+@return TRUE if the log block checksum is OK, FALSE otherwise.  */
+static
+ibool
+log_online_is_valid_log_seg(
+/*========================*/
+	const byte* log_block)	/*!< in: read log data */
+{
+	ibool checksum_is_ok
+		= log_block_checksum_is_ok_or_old_format(log_block);
+
+	if (!checksum_is_ok) {
+
+		fprintf(stderr,
+			"InnoDB Error: log block checksum mismatch"
+			"expected %lu, calculated checksum %lu\n",
+			(ulong) log_block_get_checksum(log_block),
+			(ulong) log_block_calc_checksum(log_block));
+	}
+
+	return checksum_is_ok;
+}
+
+/*********************************************************************//**
+Copy new log data to the parse buffer while skipping log block header,
+trailer and already parsed data.  */
+static
+void
+log_online_add_to_parse_buf(
+/*========================*/
+	const byte*	log_block,	/*!< in: read log data */
+	ulint		data_len,	/*!< in: length of read log data */
+	ulint		skip_len)	/*!< in: how much of log data to
+					skip */
+{
+	ulint start_offset = skip_len ? skip_len : LOG_BLOCK_HDR_SIZE;
+	ulint end_offset
+		= (data_len == OS_FILE_LOG_BLOCK_SIZE)
+		? data_len - LOG_BLOCK_TRL_SIZE
+		: data_len;
+	ulint actual_data_len = (end_offset >= start_offset)
+		? end_offset - start_offset : 0;
+
+	ut_memcpy(log_bmp_sys->parse_buf_end, log_block + start_offset,
+		  actual_data_len);
+
+	log_bmp_sys->parse_buf_end += actual_data_len;
+
+	ut_a(log_bmp_sys->parse_buf_end - log_bmp_sys->parse_buf
+	     <= RECV_PARSING_BUF_SIZE);
+}
+
+/*********************************************************************//**
+Parse the log block: first copies the read log data to the parse buffer while
+skipping log block header, trailer and already parsed data.  Then it actually
+parses the log to add to the modified page bitmap. */
+static
+void
+log_online_parse_redo_log_block(
+/*============================*/
+	const byte*	log_block,		  /*!< in: read log data */
+	ulint		skip_already_parsed_len)  /*!< in: how many bytes of
+						  log data should be skipped as
+						  they were parsed before */
+{
+	ulint block_data_len;
+
+	block_data_len = log_block_get_data_len(log_block);
+
+	ut_ad(block_data_len % OS_FILE_LOG_BLOCK_SIZE == 0
+	      || block_data_len < OS_FILE_LOG_BLOCK_SIZE);
+
+	log_online_add_to_parse_buf(log_block, block_data_len,
+				    skip_already_parsed_len);
+	log_online_parse_redo_log();
+}
+
+/*********************************************************************//**
+Read and parse one redo log chunk and updates the modified page bitmap. */
+static
+void
+log_online_follow_log_seg(
+/*======================*/
+	log_group_t*	group,		       /*!< in: the log group to use */
+	ib_uint64_t	block_start_lsn,       /*!< in: the LSN to read from */
+	ib_uint64_t	block_end_lsn)	       /*!< in: the LSN to read to */
+{
+	/* Pointer to the current OS_FILE_LOG_BLOCK-sized chunk of the read log
+	data to parse */
+	byte* log_block = log_bmp_sys->read_buf;
+	byte* log_block_end = log_bmp_sys->read_buf
+		+ (block_end_lsn - block_start_lsn);
+
+	mutex_enter(&log_sys->mutex);
+	log_group_read_log_seg(LOG_RECOVER, log_bmp_sys->read_buf,
+			       group, block_start_lsn, block_end_lsn);
+	mutex_exit(&log_sys->mutex);
+
+	while (log_block < log_block_end
+	       && log_bmp_sys->next_parse_lsn < log_bmp_sys->end_lsn) {
+
+		/* How many bytes of log data should we skip in the current log
+		block.  Skipping is necessary because we round down the next
+		parse LSN thus it is possible to read the already-processed log
+		data many times */
+		ulint skip_already_parsed_len = 0;
+
+		if (!log_online_is_valid_log_seg(log_block)) {
+			break;
+		}
+
+		if ((block_start_lsn <= log_bmp_sys->next_parse_lsn)
+		    && (block_start_lsn + OS_FILE_LOG_BLOCK_SIZE
+			> log_bmp_sys->next_parse_lsn)) {
+
+			/* The next parse LSN is inside the current block, skip
+			data preceding it. */
+			skip_already_parsed_len
+				= log_bmp_sys->next_parse_lsn
+				- block_start_lsn;
+		}
+		else {
+
+			/* If the next parse LSN is not inside the current
+			block, then the only option is that we have processed
+			ahead already. */
+			ut_a(block_start_lsn > log_bmp_sys->next_parse_lsn);
+		}
+
+		/* TODO: merge the copying to the parse buf code with
+		skip_already_len calculations */
+		log_online_parse_redo_log_block(log_block,
+						skip_already_parsed_len);
+
+		log_block += OS_FILE_LOG_BLOCK_SIZE;
+		block_start_lsn += OS_FILE_LOG_BLOCK_SIZE;
+	}
+
+	return;
+}
+
+/*********************************************************************//**
+Read and parse the redo log in a given group in FOLLOW_SCAN_SIZE-sized
+chunks and updates the modified page bitmap. */
+static
+void
+log_online_follow_log_group(
+/*========================*/
+	log_group_t*	group,		/*!< in: the log group to use */
+	ib_uint64_t	contiguous_lsn)	/*!< in: the LSN of log block start
+					containing the log_parse_start_lsn */
+{
+	ib_uint64_t block_start_lsn = contiguous_lsn;
+	ib_uint64_t block_end_lsn;
+
+	log_bmp_sys->next_parse_lsn = log_bmp_sys->start_lsn;
+	log_bmp_sys->parse_buf_end = log_bmp_sys->parse_buf;
+
+	do {
+		block_end_lsn = block_start_lsn + FOLLOW_SCAN_SIZE;
+
+		log_online_follow_log_seg(group, block_start_lsn,
+					  block_end_lsn);
+
+		/* Next parse LSN can become higher than the last read LSN
+		only in the case when the read LSN falls right on the block
+		boundary, in which case next parse lsn is bumped to the actual
+		data LSN on the next (not yet read) block.  This assert is
+		slightly conservative.  */
+		ut_a(log_bmp_sys->next_parse_lsn
+		     <= block_end_lsn + LOG_BLOCK_HDR_SIZE
+		     + LOG_BLOCK_TRL_SIZE);
+
+		block_start_lsn = block_end_lsn;
+	} while (block_end_lsn < log_bmp_sys->end_lsn);
+
+	/* Assert that the last read log record is a full one */
+	ut_a(log_bmp_sys->parse_buf_end == log_bmp_sys->parse_buf);
+}
+
+/*********************************************************************//**
+Write, flush one bitmap block to disk and advance the output position if
+successful. */
+static
+void
+log_online_write_bitmap_page(
+/*=========================*/
+	const byte *block)	/*!< in: block to write */
+{
+	ibool	success;
+
+	success = os_file_write(log_bmp_sys->out_name,log_bmp_sys->out,
+				block,
+				(ulint)(log_bmp_sys->out_offset & 0xFFFFFFFF),
+				(ulint)(log_bmp_sys->out_offset << 32),
+				MODIFIED_PAGE_BLOCK_SIZE);
+	if (UNIV_UNLIKELY(!success)) {
+
+		/* The following call prints an error message */
+		os_file_get_last_error(TRUE);
+		fprintf(stderr, "InnoDB: Error: failed writing changed page "
+			"bitmap file \'%s\'\n", log_bmp_sys->out_name);
+		return;
+	}
+
+	success = os_file_flush(log_bmp_sys->out, FALSE);
+	if (UNIV_UNLIKELY(!success)) {
+
+		/* The following call prints an error message */
+		os_file_get_last_error(TRUE);
+		fprintf(stderr, "InnoDB: Error: failed flushing "
+			"changed page bitmap file \'%s\'\n",
+			log_bmp_sys->out_name);
+		return;
+	}
+
+	log_bmp_sys->out_offset += MODIFIED_PAGE_BLOCK_SIZE;
+}
+
+/*********************************************************************//**
+Append the current changed page bitmap to the bitmap file.  Clears the
+bitmap tree and recycles its nodes to the free list. */
+static
+void
+log_online_write_bitmap()
+/*=====================*/
+{
+	ib_rbt_node_t		*bmp_tree_node;
+	const ib_rbt_node_t	*last_bmp_tree_node;
+
+	bmp_tree_node = (ib_rbt_node_t *)
+		rbt_first(log_bmp_sys->modified_pages);
+	last_bmp_tree_node = rbt_last(log_bmp_sys->modified_pages);
+
+	while (bmp_tree_node) {
+
+		byte *page = rbt_value(byte, bmp_tree_node);
+
+		if (bmp_tree_node == last_bmp_tree_node) {
+			mach_write_to_4(page + MODIFIED_PAGE_IS_LAST_BLOCK, 1);
+		}
+
+		mach_write_to_8(page + MODIFIED_PAGE_START_LSN,
+				log_bmp_sys->start_lsn);
+		mach_write_to_8(page + MODIFIED_PAGE_END_LSN,
+				log_bmp_sys->end_lsn);
+		mach_write_to_4(page + MODIFIED_PAGE_BLOCK_CHECKSUM,
+				log_online_calc_checksum(page));
+
+		log_online_write_bitmap_page(page);
+
+		bmp_tree_node->left = log_bmp_sys->page_free_list;
+		log_bmp_sys->page_free_list = bmp_tree_node;
+
+		bmp_tree_node = (ib_rbt_node_t*)
+			rbt_next(log_bmp_sys->modified_pages, bmp_tree_node);
+	}
+
+	rbt_reset(log_bmp_sys->modified_pages);
+}
+
+/*********************************************************************//**
+Read and parse the redo log up to last checkpoint LSN to build the changed
+page bitmap which is then written to disk.  */
+UNIV_INTERN
+void
+log_online_follow_redo_log()
+/*========================*/
+{
+	ib_uint64_t	contiguous_start_lsn;
+	log_group_t*	group;
+
+	/* Grab the LSN of the last checkpoint, we will parse up to it */
+	mutex_enter(&(log_sys->mutex));
+	log_bmp_sys->end_lsn = log_sys->last_checkpoint_lsn;
+	mutex_exit(&(log_sys->mutex));
+
+	if (log_bmp_sys->end_lsn == log_bmp_sys->start_lsn) {
+		return;
+	}
+
+	group = UT_LIST_GET_FIRST(log_sys->log_groups);
+	ut_a(group);
+
+	contiguous_start_lsn = ut_uint64_align_down(log_bmp_sys->start_lsn,
+						    OS_FILE_LOG_BLOCK_SIZE);
+
+	while (group) {
+		log_online_follow_log_group(group, contiguous_start_lsn);
+		group = UT_LIST_GET_NEXT(log_groups, group);
+	}
+
+	/* A crash injection site that ensures last checkpoint LSN > last
+	tracked LSN, so that LSN tracking for this interval is tested. */
+	DBUG_EXECUTE_IF("crash_before_bitmap_write", DBUG_SUICIDE(););
+
+	log_online_write_bitmap();
+	log_bmp_sys->start_lsn = log_bmp_sys->end_lsn;
+	log_set_tracked_lsn(log_bmp_sys->start_lsn);
+}
+
+/*********************************************************************//**
+Initializes log bitmap iterator.
+@return TRUE if the iterator is initialized OK, FALSE otherwise. */
+UNIV_INTERN
+ibool
+log_online_bitmap_iterator_init(
+/*============================*/
+	log_bitmap_iterator_t *i) /*!<in/out:  iterator */
+{
+	ibool	success;
+
+	ut_a(i);
+	ut_snprintf(i->in_name, FN_REFLEN, "%s%s%d", srv_data_home,
+		    modified_page_stem, 1);
+	i->in_offset = 0;
+	/*
+	  Set up bit offset out of the reasonable limit
+	  to intiate reading block from file in
+	  log_online_bitmap_iterator_next()
+	*/
+	i->bit_offset = MODIFIED_PAGE_BLOCK_BITMAP_LEN;
+	i->in =
+		os_file_create_simple_no_error_handling(innodb_file_bmp_key,
+							i->in_name,
+							OS_FILE_OPEN,
+							OS_FILE_READ_ONLY,
+							&success);
+
+	if (!success) {
+		/* The following call prints an error message */
+		os_file_get_last_error(TRUE);
+		fprintf(stderr,
+			"InnoDB: Error: Cannot open \'%s\'\n",
+			i->in_name);
+		return FALSE;
+	}
+
+	i->page = ut_malloc(MODIFIED_PAGE_BLOCK_SIZE);
+
+	i->start_lsn = i->end_lsn = 0;
+	i->space_id = 0;
+	i->first_page_id = 0;
+	i->changed = FALSE;
+
+	return TRUE;
+}
+
+/*********************************************************************//**
+Releases log bitmap iterator. */
+UNIV_INTERN
+void
+log_online_bitmap_iterator_release(
+/*===============================*/
+	log_bitmap_iterator_t *i) /*!<in/out:  iterator */
+{
+	ut_a(i);
+	os_file_close(i->in);
+	ut_free(i->page);
+}
+
+/*********************************************************************//**
+Iterates through bits of saved bitmap blocks.
+Sequentially reads blocks from bitmap file(s) and interates through
+their bits. Ignores blocks with wrong checksum.
+@return TRUE if iteration is successful, FALSE if all bits are iterated. */
+UNIV_INTERN
+ibool
+log_online_bitmap_iterator_next(
+/*============================*/
+	log_bitmap_iterator_t *i) /*!<in/out: iterator */
+{
+	ulint	offset_low;
+	ulint	offset_high;
+	ulint	size_low;
+	ulint	size_high;
+	ulint	checksum	= 0;
+	ulint	actual_checksum	= !checksum;
+
+	ibool	success;
+
+	ut_a(i);
+
+	if (i->bit_offset < MODIFIED_PAGE_BLOCK_BITMAP_LEN)
+	{
+		++i->bit_offset;
+		i->changed =
+			IS_BIT_SET(i->page + MODIFIED_PAGE_BLOCK_BITMAP,
+				   i->bit_offset);
+		return TRUE;
+	}
+
+	while (checksum != actual_checksum)
+	{
+		success = os_file_get_size(i->in,
+					   &size_low,
+					   &size_high);
+		if (!success) {
+			os_file_get_last_error(TRUE);
+			fprintf(stderr,
+				"InnoDB: Warning: can't get size of "
+				"page bitmap file \'%s\'\n",
+				i->in_name);
+			return FALSE;
+		}
+
+		if (i->in_offset >=
+		    (ib_uint64_t)(size_low) +
+		    ((ib_uint64_t)(size_high) << 32))
+			return FALSE;
+
+		offset_high = (ulint)(i->in_offset >> 32);
+		offset_low = (ulint)(i->in_offset & 0xFFFFFFFF);
+
+		success = os_file_read(
+				       i->in,
+				       i->page,
+				       offset_low,
+				       offset_high,
+				       MODIFIED_PAGE_BLOCK_SIZE);
+
+		if (!success) {
+			os_file_get_last_error(TRUE);
+			fprintf(stderr,
+				"InnoDB: Warning: failed reading "
+				"changed page bitmap file \'%s\'\n",
+				i->in_name);
+			return FALSE;
+		}
+
+		checksum = mach_read_from_4(
+			i->page + MODIFIED_PAGE_BLOCK_CHECKSUM);
+
+		actual_checksum = log_online_calc_checksum(i->page);
+
+		i->in_offset += MODIFIED_PAGE_BLOCK_SIZE;
+	}
+
+	i->start_lsn =
+		mach_read_from_8(i->page + MODIFIED_PAGE_START_LSN);
+	i->end_lsn =
+		mach_read_from_8(i->page + MODIFIED_PAGE_END_LSN);
+	i->space_id =
+		mach_read_from_4(i->page + MODIFIED_PAGE_SPACE_ID);
+	i->first_page_id =
+		mach_read_from_4(i->page + MODIFIED_PAGE_1ST_PAGE_ID);
+	i->bit_offset =
+		0;
+	i->changed  =
+		IS_BIT_SET(i->page + MODIFIED_PAGE_BLOCK_BITMAP,
+			   i->bit_offset);
+
+	return TRUE;
+}
+
diff --git a/storage/xtradb/log/log0recv.c b/storage/xtradb/log/log0recv.c
index a554c576b6d..5ab8c14ae2e 100644
--- a/storage/xtradb/log/log0recv.c
+++ b/storage/xtradb/log/log0recv.c
@@ -857,7 +857,7 @@ block.  We also accept a log block in the old format before
 InnoDB-3.23.52 where the checksum field contains the log block number.
 @return TRUE if ok, or if the log block may be in the format of InnoDB
 version predating 3.23.52 */
-static
+UNIV_INTERN
 ibool
 log_block_checksum_is_ok_or_old_format(
 /*===================================*/
@@ -2102,7 +2102,7 @@ skip_this_recv_addr:
 /*******************************************************************//**
 Tries to parse a single log record and returns its length.
 @return	length of the record, or 0 if the record was not complete */
-static
+UNIV_INTERN
 ulint
 recv_parse_log_rec(
 /*===============*/
@@ -2173,7 +2173,7 @@ recv_parse_log_rec(
 
 /*******************************************************//**
 Calculates the new value for lsn when more data is added to the log. */
-static
+UNIV_INTERN
 ib_uint64_t
 recv_calc_lsn_on_data_add(
 /*======================*/
@@ -3570,6 +3570,8 @@ recv_reset_logs(
 	log_sys->archived_lsn = log_sys->lsn;
 #endif /* UNIV_LOG_ARCHIVE */
 
+	log_sys->tracked_lsn = log_sys->lsn;
+
 	log_block_init(log_sys->buf, log_sys->lsn);
 	log_block_set_first_rec_group(log_sys->buf, LOG_BLOCK_HDR_SIZE);
 
diff --git a/storage/xtradb/os/os0file.c b/storage/xtradb/os/os0file.c
index 061d556c6e7..8fa2cdb4a28 100644
--- a/storage/xtradb/os/os0file.c
+++ b/storage/xtradb/os/os0file.c
@@ -158,6 +158,7 @@ UNIV_INTERN ibool	os_aio_print_debug	= FALSE;
 UNIV_INTERN mysql_pfs_key_t  innodb_file_data_key;
 UNIV_INTERN mysql_pfs_key_t  innodb_file_log_key;
 UNIV_INTERN mysql_pfs_key_t  innodb_file_temp_key;
+UNIV_INTERN mysql_pfs_key_t  innodb_file_bmp_key;
 #endif /* UNIV_PFS_IO */
 
 /** The asynchronous i/o array slot structure */
@@ -2147,6 +2148,25 @@ os_file_set_eof(
 #endif /* __WIN__ */
 }
 
+/***********************************************************************//**
+Truncates a file at the specified position.
+@return TRUE if success */
+UNIV_INTERN
+ibool
+os_file_set_eof_at(
+	os_file_t	file, /*!< in: handle to a file */
+	ib_uint64_t	new_len)/*!< in: new file length */
+{
+#ifdef __WIN__
+	/* TODO: untested! */
+	return(!_chsize_s(file, new_len));
+#else
+	/* TODO: works only with -D_FILE_OFFSET_BITS=64 ? */
+	return(!ftruncate(file, new_len));
+#endif
+}
+
+
 #ifndef __WIN__
 /***********************************************************************//**
 Wrapper to fsync(2) that retries the call on some errors.
diff --git a/storage/xtradb/srv/srv0srv.c b/storage/xtradb/srv/srv0srv.c
index 0a545a8247a..dff9fc07a7f 100644
--- a/storage/xtradb/srv/srv0srv.c
+++ b/storage/xtradb/srv/srv0srv.c
@@ -67,6 +67,7 @@ Created 10/8/1995 Heikki Tuuri
 #include "mem0pool.h"
 #include "sync0sync.h"
 #include "que0que.h"
+#include "log0online.h"
 #include "log0recv.h"
 #include "pars0pars.h"
 #include "usr0sess.h"
@@ -176,6 +177,10 @@ UNIV_INTERN char*	srv_doublewrite_file = NULL;
 
 UNIV_INTERN ibool	srv_recovery_stats = FALSE;
 
+UNIV_INTERN my_bool	srv_track_changed_pages = TRUE;
+
+UNIV_INTERN ulonglong	srv_changed_pages_limit = 0;
+
 /* if TRUE, then we auto-extend the last data file */
 UNIV_INTERN ibool	srv_auto_extend_last_data_file	= FALSE;
 /* if != 0, this tells the max size auto-extending may increase the
@@ -771,6 +776,10 @@ UNIV_INTERN os_event_t	srv_lock_timeout_thread_event;
 
 UNIV_INTERN os_event_t	srv_shutdown_event;
 
+UNIV_INTERN os_event_t	srv_checkpoint_completed_event;
+
+UNIV_INTERN os_event_t	srv_redo_log_thread_finished_event;
+
 UNIV_INTERN srv_sys_t*	srv_sys	= NULL;
 
 /* padding to prevent other memory update hotspots from residing on
@@ -1110,6 +1119,9 @@ srv_init(void)
 	srv_lock_timeout_thread_event = os_event_create(NULL);
 	srv_shutdown_event = os_event_create(NULL);
 
+	srv_checkpoint_completed_event = os_event_create(NULL);
+	srv_redo_log_thread_finished_event = os_event_create(NULL);
+
 	for (i = 0; i < SRV_MASTER + 1; i++) {
 		srv_n_threads_active[i] = 0;
 		srv_n_threads[i] = 0;
@@ -3034,6 +3046,46 @@ srv_shutdown_print_master_pending(
         }
 }
 
+/******************************************************************//**
+A thread which follows the redo log and outputs the changed page bitmap.
+@return a dummy value */
+os_thread_ret_t
+srv_redo_log_follow_thread(
+/*=======================*/
+	void*	arg __attribute__((unused)))	/*!< in: a dummy parameter
+						     required by
+						     os_thread_create */
+{
+#ifdef UNIV_DEBUG_THREAD_CREATION
+	fprintf(stderr, "Redo log follower thread starts, id %lu\n",
+		os_thread_pf(os_thread_get_curr_id()));
+#endif
+
+#ifdef UNIV_PFS_THREAD
+	pfs_register_thread(srv_log_tracking_thread_key);
+#endif
+
+	my_thread_init();
+
+	do {
+		os_event_wait(srv_checkpoint_completed_event);
+		os_event_reset(srv_checkpoint_completed_event);
+
+		if (srv_shutdown_state < SRV_SHUTDOWN_LAST_PHASE) {
+			log_online_follow_redo_log();
+		}
+
+	} while (srv_shutdown_state < SRV_SHUTDOWN_LAST_PHASE);
+
+	log_online_read_shutdown();
+	os_event_set(srv_redo_log_thread_finished_event);
+
+	my_thread_end();
+	os_thread_exit(NULL);
+
+	OS_THREAD_DUMMY_RETURN;
+}
+
 /*******************************************************************//**
 Tells the InnoDB server that there has been activity in the database
 and wakes up the master thread if it is suspended (not sleeping). Used
diff --git a/storage/xtradb/srv/srv0start.c b/storage/xtradb/srv/srv0start.c
index d1329f445aa..7c98f74909e 100644
--- a/storage/xtradb/srv/srv0start.c
+++ b/storage/xtradb/srv/srv0start.c
@@ -51,6 +51,7 @@ Created 2/16/1996 Heikki Tuuri
 #include "rem0rec.h"
 #include "mtr0mtr.h"
 #include "log0log.h"
+#include "log0online.h"
 #include "log0recv.h"
 #include "page0page.h"
 #include "page0cur.h"
@@ -121,9 +122,9 @@ UNIV_INTERN enum srv_shutdown_state	srv_shutdown_state = SRV_SHUTDOWN_NONE;
 static os_file_t	files[1000];
 
 /** io_handler_thread parameters for thread identification */
-static ulint		n[SRV_MAX_N_IO_THREADS + 7];
+static ulint		n[SRV_MAX_N_IO_THREADS + 8];
 /** io_handler_thread identifiers */
-static os_thread_id_t	thread_ids[SRV_MAX_N_IO_THREADS + 7];
+static os_thread_id_t	thread_ids[SRV_MAX_N_IO_THREADS + 8];
 
 /** We use this mutex to test the return value of pthread_mutex_trylock
    on successful locking. HP-UX does NOT return 0, though Linux et al do. */
@@ -145,6 +146,7 @@ UNIV_INTERN mysql_pfs_key_t	srv_error_monitor_thread_key;
 UNIV_INTERN mysql_pfs_key_t	srv_monitor_thread_key;
 UNIV_INTERN mysql_pfs_key_t	srv_master_thread_key;
 UNIV_INTERN mysql_pfs_key_t	srv_purge_thread_key;
+UNIV_INTERN mysql_pfs_key_t	srv_log_tracking_thread_key;
 #endif /* UNIV_PFS_THREAD */
 
 /*********************************************************************//**
@@ -2037,6 +2039,19 @@ innobase_start_or_create_for_mysql(void)
 	if (srv_auto_lru_dump && srv_blocking_lru_restore)
 		buf_LRU_file_restore();
 
+	if (srv_track_changed_pages) {
+
+		/* Initialize the log tracking subsystem here to block
+		server startup until it's completed due to the potential
+		need to re-read previous server run's log. */
+		log_online_read_init();
+
+		/* Create the thread that follows the redo log to output the
+		changed page bitmap */
+		os_thread_create(&srv_redo_log_follow_thread, NULL,
+				 thread_ids + 6 + SRV_MAX_N_IO_THREADS);
+	}
+
 	srv_is_being_started = FALSE;
 
 	err = dict_create_or_check_foreign_constraint_tables();
diff --git a/storage/xtradb/ut/ut0rbt.c b/storage/xtradb/ut/ut0rbt.c
index 3d7cfa7636f..a5e9081b951 100644
--- a/storage/xtradb/ut/ut0rbt.c
+++ b/storage/xtradb/ut/ut0rbt.c
@@ -55,7 +55,6 @@ red-black properties:
 #endif
 
 #define ROOT(t)		(t->root->left)
-#define	SIZEOF_NODE(t)	((sizeof(ib_rbt_node_t) + t->sizeof_value) - 1)
 
 /**********************************************************************//**
 Print out the sub-tree recursively. */
@@ -834,6 +833,21 @@ rbt_add_node(
 	node = (ib_rbt_node_t*) ut_malloc(SIZEOF_NODE(tree));
 
 	memcpy(node->value, value, tree->sizeof_value);
+	return(rbt_add_preallocated_node(tree, parent, node));
+}
+
+/****************************************************************//**
+Add a new caller-provided node to tree at the specified position.
+The node must have its key fields initialized correctly.
+@return added node */
+UNIV_INTERN
+const ib_rbt_node_t*
+rbt_add_preallocated_node(
+/*======================*/
+	ib_rbt_t*	tree,			/*!< in: rb tree */
+	ib_rbt_bound_t*	parent,			/*!< in: parent */
+	ib_rbt_node_t*	node)			/*!< in: node */
+{
 	node->parent = node->left = node->right = tree->nil;
 
 	/* If tree is empty */
@@ -842,7 +856,7 @@ rbt_add_node(
 	}
 
 	/* Append the node, the hope here is that the caller knows
-	what s/he is doing. */
+	   what s/he is doing. */
 	rbt_tree_add_child(tree, parent, node);
 	rbt_balance_tree(tree, node);
 
@@ -854,6 +868,7 @@ rbt_add_node(
 	return(node);
 }
 
+
 /**********************************************************************//**
 Find a matching node in the rb tree.
 @return	NULL if not found else the node where key was found */
@@ -1142,7 +1157,17 @@ rbt_clear(
 	ib_rbt_t*	tree)			/*!< in: rb tree */
 {
 	rbt_free_node(ROOT(tree), tree->nil);
+	rbt_reset(tree);
+}
 
+/****************************************************************//**
+Clear the tree without deleting and freeing its nodes. */
+UNIV_INTERN
+void
+rbt_reset(
+/*======*/
+	ib_rbt_t*	tree)			/*!< in: rb tree */
+{
 	tree->n_nodes = 0;
 	tree->root->left = tree->root->right = tree->nil;
 }