diff --git a/mysql-test/suite/innodb/r/innodb_bug59733.result b/mysql-test/suite/innodb/r/innodb_bug59733.result
new file mode 100644
index 00000000000..c962cdfd677
--- /dev/null
+++ b/mysql-test/suite/innodb/r/innodb_bug59733.result
@@ -0,0 +1,18 @@
+CREATE TABLE bug59733(a INT AUTO_INCREMENT PRIMARY KEY,b CHAR(1))ENGINE=InnoDB;
+INSERT INTO bug59733 VALUES(0,'x');
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+CREATE INDEX b ON bug59733 (b);
+DELETE FROM bug59733 WHERE (a%100)=0;
+DROP INDEX b ON bug59733;
+CREATE INDEX b ON bug59733 (b);
+DROP TABLE bug59733;
diff --git a/mysql-test/suite/innodb/t/innodb_bug59733.test b/mysql-test/suite/innodb/t/innodb_bug59733.test
new file mode 100644
index 00000000000..0b1bff51932
--- /dev/null
+++ b/mysql-test/suite/innodb/t/innodb_bug59733.test
@@ -0,0 +1,53 @@
+#
+# Bug #59733 Possible deadlock when buffered changes are to be discarded
+# in buf_page_create
+#
+-- source include/have_innodb.inc
+
+-- disable_query_log
+# The flag innodb_change_buffering_debug is only available in debug builds.
+# It instructs InnoDB to try to evict pages from the buffer pool when
+# change buffering is possible, so that the change buffer will be used
+# whenever possible.
+-- error 0,ER_UNKNOWN_SYSTEM_VARIABLE
+SET @innodb_change_buffering_debug_orig = @@innodb_change_buffering_debug;
+-- error 0,ER_UNKNOWN_SYSTEM_VARIABLE
+SET GLOBAL innodb_change_buffering_debug = 1;
+-- enable_query_log
+
+CREATE TABLE bug59733(a INT AUTO_INCREMENT PRIMARY KEY,b CHAR(1))ENGINE=InnoDB;
+
+# Create enough rows for the table, so that the insert buffer will be
+# used. There must be multiple index pages, because changes to the
+# root page are never buffered.
+
+INSERT INTO bug59733 VALUES(0,'x');
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+INSERT INTO bug59733 SELECT 0,b FROM bug59733;
+
+# Create the secondary index for which changes will be buffered.
+CREATE INDEX b ON bug59733 (b);
+
+# This should be buffered, if innodb_change_buffering_debug = 1 is in effect.
+DELETE FROM bug59733 WHERE (a%100)=0;
+
+# Drop the index in order to get free pages with orphaned buffered changes.
+DROP INDEX b ON bug59733;
+
+# Create the index and attempt to reuse pages for which buffered changes exist.
+CREATE INDEX b ON bug59733 (b);
+
+DROP TABLE bug59733;
+
+-- disable_query_log
+-- error 0, ER_UNKNOWN_SYSTEM_VARIABLE
+SET GLOBAL innodb_change_buffering_debug = @innodb_change_buffering_debug_orig;
diff --git a/storage/innobase/btr/btr0btr.c b/storage/innobase/btr/btr0btr.c
index 3d8fadeaf92..4ce94854f7a 100644
--- a/storage/innobase/btr/btr0btr.c
+++ b/storage/innobase/btr/btr0btr.c
@@ -690,7 +690,8 @@ btr_root_block_get(
 	zip_size = dict_table_zip_size(index->table);
 	root_page_no = dict_index_get_page(index);
 
-	block = btr_block_get(space, zip_size, root_page_no, RW_X_LATCH, mtr);
+	block = btr_block_get(space, zip_size, root_page_no, RW_X_LATCH,
+			      index, mtr);
 	ut_a((ibool)!!page_is_comp(buf_block_get_frame(block))
 	     == dict_table_is_comp(index->table));
 #ifdef UNIV_BTR_DEBUG
@@ -891,7 +892,7 @@ btr_page_alloc_for_ibuf(
 				 dict_table_zip_size(index->table),
 				 node_addr.page, RW_X_LATCH, mtr);
 	new_page = buf_block_get_frame(new_block);
-	buf_block_dbg_add_level(new_block, SYNC_TREE_NODE_NEW);
+	buf_block_dbg_add_level(new_block, SYNC_IBUF_TREE_NODE_NEW);
 
 	flst_remove(root + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST,
 		    new_page + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST_NODE,
@@ -1139,7 +1140,7 @@ btr_node_ptr_get_child(
 	page_no = btr_node_ptr_get_child_page_no(node_ptr, offsets);
 
 	return(btr_block_get(space, dict_table_zip_size(index->table),
-			     page_no, RW_X_LATCH, mtr));
+			     page_no, RW_X_LATCH, index, mtr));
 }
 
 /************************************************************//**
@@ -1312,7 +1313,8 @@ btr_create(
 			space, 0,
 			IBUF_HEADER + IBUF_TREE_SEG_HEADER, mtr);
 
-		buf_block_dbg_add_level(ibuf_hdr_block, SYNC_TREE_NODE_NEW);
+		buf_block_dbg_add_level(
+			ibuf_hdr_block, SYNC_IBUF_TREE_NODE_NEW);
 
 		ut_ad(buf_block_get_page_no(ibuf_hdr_block)
 		      == IBUF_HEADER_PAGE_NO);
@@ -1350,10 +1352,9 @@ btr_create(
 	page_no = buf_block_get_page_no(block);
 	frame = buf_block_get_frame(block);
 
-	buf_block_dbg_add_level(block, SYNC_TREE_NODE_NEW);
-
 	if (type & DICT_IBUF) {
 		/* It is an insert buffer tree: initialize the free list */
+		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE_NEW);
 
 		ut_ad(page_no == IBUF_TREE_ROOT_PAGE_NO);
 
@@ -1361,6 +1362,8 @@ btr_create(
 	} else {
 		/* It is a non-ibuf tree: create a file segment for leaf
 		pages */
+		buf_block_dbg_add_level(block, SYNC_TREE_NODE_NEW);
+
 		if (!fseg_create(space, page_no,
 				 PAGE_HEADER + PAGE_BTR_SEG_LEAF, mtr)) {
 			/* Not enough space for new segment, free root
@@ -1432,7 +1435,8 @@ btr_free_but_not_root(
 leaf_loop:
 	mtr_start(&mtr);
 
-	root = btr_page_get(space, zip_size, root_page_no, RW_X_LATCH, &mtr);
+	root = btr_page_get(space, zip_size, root_page_no, RW_X_LATCH,
+			    NULL, &mtr);
 #ifdef UNIV_BTR_DEBUG
 	ut_a(btr_root_fseg_validate(FIL_PAGE_DATA + PAGE_BTR_SEG_LEAF
 				    + root, space));
@@ -1454,7 +1458,8 @@ leaf_loop:
 top_loop:
 	mtr_start(&mtr);
 
-	root = btr_page_get(space, zip_size, root_page_no, RW_X_LATCH, &mtr);
+	root = btr_page_get(space, zip_size, root_page_no, RW_X_LATCH,
+			    NULL, &mtr);
 #ifdef UNIV_BTR_DEBUG
 	ut_a(btr_root_fseg_validate(FIL_PAGE_DATA + PAGE_BTR_SEG_TOP
 				    + root, space));
@@ -1480,13 +1485,13 @@ btr_free_root(
 	ulint	zip_size,	/*!< in: compressed page size in bytes
 				or 0 for uncompressed pages */
 	ulint	root_page_no,	/*!< in: root page number */
-	mtr_t*	mtr)		/*!< in: a mini-transaction which has already
-				been started */
+	mtr_t*	mtr)		/*!< in/out: mini-transaction */
 {
 	buf_block_t*	block;
 	fseg_header_t*	header;
 
-	block = btr_block_get(space, zip_size, root_page_no, RW_X_LATCH, mtr);
+	block = btr_block_get(space, zip_size, root_page_no, RW_X_LATCH,
+			      NULL, mtr);
 
 	btr_search_drop_page_hash_index(block);
 
@@ -2365,9 +2370,8 @@ btr_attach_half_pages(
 	/* Update page links of the level */
 
 	if (prev_page_no != FIL_NULL) {
-		buf_block_t*	prev_block = btr_block_get(space, zip_size,
-							   prev_page_no,
-							   RW_X_LATCH, mtr);
+		buf_block_t*	prev_block = btr_block_get(
+			space, zip_size, prev_page_no, RW_X_LATCH, index, mtr);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(page_is_comp(prev_block->frame) == page_is_comp(page));
 		ut_a(btr_page_get_next(prev_block->frame, mtr)
@@ -2380,9 +2384,8 @@ btr_attach_half_pages(
 	}
 
 	if (next_page_no != FIL_NULL) {
-		buf_block_t*	next_block = btr_block_get(space, zip_size,
-							   next_page_no,
-							   RW_X_LATCH, mtr);
+		buf_block_t*	next_block = btr_block_get(
+			space, zip_size, next_page_no, RW_X_LATCH, index, mtr);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(page_is_comp(next_block->frame) == page_is_comp(page));
 		ut_a(btr_page_get_prev(next_block->frame, mtr)
@@ -2804,17 +2807,42 @@ func_exit:
 	return(rec);
 }
 
+#ifdef UNIV_SYNC_DEBUG
+/*************************************************************//**
+Removes a page from the level list of pages.
+@param space	in: space where removed
+@param zip_size	in: compressed page size in bytes, or 0 for uncompressed
+@param page	in/out: page to remove
+@param index	in: index tree
+@param mtr	in/out: mini-transaction */
+# define btr_level_list_remove(space,zip_size,page,index,mtr)		\
+	btr_level_list_remove_func(space,zip_size,page,index,mtr)
+#else /* UNIV_SYNC_DEBUG */
+/*************************************************************//**
+Removes a page from the level list of pages.
+@param space	in: space where removed
+@param zip_size	in: compressed page size in bytes, or 0 for uncompressed
+@param page	in/out: page to remove
+@param index	in: index tree
+@param mtr	in/out: mini-transaction */
+# define btr_level_list_remove(space,zip_size,page,index,mtr)		\
+	btr_level_list_remove_func(space,zip_size,page,mtr)
+#endif /* UNIV_SYNC_DEBUG */
+
 /*************************************************************//**
 Removes a page from the level list of pages. */
-static
+static __attribute__((nonnull))
 void
-btr_level_list_remove(
-/*==================*/
-	ulint		space,	/*!< in: space where removed */
-	ulint		zip_size,/*!< in: compressed page size in bytes
-				or 0 for uncompressed pages */
-	page_t*		page,	/*!< in: page to remove */
-	mtr_t*		mtr)	/*!< in: mtr */
+btr_level_list_remove_func(
+/*=======================*/
+	ulint			space,	/*!< in: space where removed */
+	ulint			zip_size,/*!< in: compressed page size in bytes
+					or 0 for uncompressed pages */
+	page_t*			page,	/*!< in/out: page to remove */
+#ifdef UNIV_SYNC_DEBUG
+	const dict_index_t*	index,	/*!< in: index tree */
+#endif /* UNIV_SYNC_DEBUG */
+	mtr_t*			mtr)	/*!< in/out: mini-transaction */
 {
 	ulint	prev_page_no;
 	ulint	next_page_no;
@@ -2832,7 +2860,7 @@ btr_level_list_remove(
 	if (prev_page_no != FIL_NULL) {
 		buf_block_t*	prev_block
 			= btr_block_get(space, zip_size, prev_page_no,
-					RW_X_LATCH, mtr);
+					RW_X_LATCH, index, mtr);
 		page_t*		prev_page
 			= buf_block_get_frame(prev_block);
 #ifdef UNIV_BTR_DEBUG
@@ -2849,7 +2877,7 @@ btr_level_list_remove(
 	if (next_page_no != FIL_NULL) {
 		buf_block_t*	next_block
 			= btr_block_get(space, zip_size, next_page_no,
-					RW_X_LATCH, mtr);
+					RW_X_LATCH, index, mtr);
 		page_t*		next_page
 			= buf_block_get_frame(next_block);
 #ifdef UNIV_BTR_DEBUG
@@ -3175,7 +3203,7 @@ btr_compress(
 	if (is_left) {
 
 		merge_block = btr_block_get(space, zip_size, left_page_no,
-					    RW_X_LATCH, mtr);
+					    RW_X_LATCH, index, mtr);
 		merge_page = buf_block_get_frame(merge_block);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(btr_page_get_next(merge_page, mtr)
@@ -3184,7 +3212,7 @@ btr_compress(
 	} else if (right_page_no != FIL_NULL) {
 
 		merge_block = btr_block_get(space, zip_size, right_page_no,
-					    RW_X_LATCH, mtr);
+					    RW_X_LATCH, index, mtr);
 		merge_page = buf_block_get_frame(merge_block);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(btr_page_get_prev(merge_page, mtr)
@@ -3273,7 +3301,7 @@ err_exit:
 		btr_search_drop_page_hash_index(block);
 
 		/* Remove the page from the level list */
-		btr_level_list_remove(space, zip_size, page, mtr);
+		btr_level_list_remove(space, zip_size, page, index, mtr);
 
 		btr_node_ptr_delete(index, block, mtr);
 		lock_update_merge_left(merge_block, orig_pred, block);
@@ -3330,7 +3358,7 @@ err_exit:
 #endif /* UNIV_BTR_DEBUG */
 
 		/* Remove the page from the level list */
-		btr_level_list_remove(space, zip_size, page, mtr);
+		btr_level_list_remove(space, zip_size, page, index, mtr);
 
 		/* Replace the address of the old child node (= page) with the
 		address of the merge page to the right */
@@ -3522,7 +3550,7 @@ btr_discard_page(
 
 	if (left_page_no != FIL_NULL) {
 		merge_block = btr_block_get(space, zip_size, left_page_no,
-					    RW_X_LATCH, mtr);
+					    RW_X_LATCH, index, mtr);
 		merge_page = buf_block_get_frame(merge_block);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(btr_page_get_next(merge_page, mtr)
@@ -3530,7 +3558,7 @@ btr_discard_page(
 #endif /* UNIV_BTR_DEBUG */
 	} else if (right_page_no != FIL_NULL) {
 		merge_block = btr_block_get(space, zip_size, right_page_no,
-					    RW_X_LATCH, mtr);
+					    RW_X_LATCH, index, mtr);
 		merge_page = buf_block_get_frame(merge_block);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(btr_page_get_prev(merge_page, mtr)
@@ -3565,7 +3593,7 @@ btr_discard_page(
 	btr_node_ptr_delete(index, block, mtr);
 
 	/* Remove the page from the level list */
-	btr_level_list_remove(space, zip_size, page, mtr);
+	btr_level_list_remove(space, zip_size, page, index, mtr);
 #ifdef UNIV_ZIP_DEBUG
 	{
 		page_zip_des_t*	merge_page_zip
@@ -4083,7 +4111,7 @@ loop:
 	if (right_page_no != FIL_NULL) {
 		const rec_t*	right_rec;
 		right_block = btr_block_get(space, zip_size, right_page_no,
-					    RW_X_LATCH, &mtr);
+					    RW_X_LATCH, index, &mtr);
 		right_page = buf_block_get_frame(right_block);
 		if (UNIV_UNLIKELY(btr_page_get_prev(right_page, &mtr)
 				  != page_get_page_no(page))) {
@@ -4309,7 +4337,7 @@ node_ptr_fails:
 		mtr_start(&mtr);
 
 		block = btr_block_get(space, zip_size, right_page_no,
-				      RW_X_LATCH, &mtr);
+				      RW_X_LATCH, index, &mtr);
 		page = buf_block_get_frame(block);
 
 		goto loop;
diff --git a/storage/innobase/btr/btr0cur.c b/storage/innobase/btr/btr0cur.c
index 46a52b549af..133b40e2d7b 100644
--- a/storage/innobase/btr/btr0cur.c
+++ b/storage/innobase/btr/btr0cur.c
@@ -249,7 +249,8 @@ btr_cur_latch_leaves(
 	case BTR_SEARCH_LEAF:
 	case BTR_MODIFY_LEAF:
 		mode = latch_mode == BTR_SEARCH_LEAF ? RW_S_LATCH : RW_X_LATCH;
-		get_block = btr_block_get(space, zip_size, page_no, mode, mtr);
+		get_block = btr_block_get(
+			space, zip_size, page_no, mode, cursor->index, mtr);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(page_is_comp(get_block->frame) == page_is_comp(page));
 #endif /* UNIV_BTR_DEBUG */
@@ -260,9 +261,9 @@ btr_cur_latch_leaves(
 		left_page_no = btr_page_get_prev(page, mtr);
 
 		if (left_page_no != FIL_NULL) {
-			get_block = btr_block_get(space, zip_size,
-						  left_page_no,
-						  RW_X_LATCH, mtr);
+			get_block = btr_block_get(
+				space, zip_size, left_page_no,
+				RW_X_LATCH, cursor->index, mtr);
 #ifdef UNIV_BTR_DEBUG
 			ut_a(page_is_comp(get_block->frame)
 			     == page_is_comp(page));
@@ -272,8 +273,9 @@ btr_cur_latch_leaves(
 			get_block->check_index_page_at_flush = TRUE;
 		}
 
-		get_block = btr_block_get(space, zip_size, page_no,
-					  RW_X_LATCH, mtr);
+		get_block = btr_block_get(
+			space, zip_size, page_no,
+			RW_X_LATCH, cursor->index, mtr);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(page_is_comp(get_block->frame) == page_is_comp(page));
 #endif /* UNIV_BTR_DEBUG */
@@ -282,9 +284,9 @@ btr_cur_latch_leaves(
 		right_page_no = btr_page_get_next(page, mtr);
 
 		if (right_page_no != FIL_NULL) {
-			get_block = btr_block_get(space, zip_size,
-						  right_page_no,
-						  RW_X_LATCH, mtr);
+			get_block = btr_block_get(
+				space, zip_size, right_page_no,
+				RW_X_LATCH, cursor->index, mtr);
 #ifdef UNIV_BTR_DEBUG
 			ut_a(page_is_comp(get_block->frame)
 			     == page_is_comp(page));
@@ -303,8 +305,9 @@ btr_cur_latch_leaves(
 		left_page_no = btr_page_get_prev(page, mtr);
 
 		if (left_page_no != FIL_NULL) {
-			get_block = btr_block_get(space, zip_size,
-						  left_page_no, mode, mtr);
+			get_block = btr_block_get(
+				space, zip_size,
+				left_page_no, mode, cursor->index, mtr);
 			cursor->left_block = get_block;
 #ifdef UNIV_BTR_DEBUG
 			ut_a(page_is_comp(get_block->frame)
@@ -315,7 +318,8 @@ btr_cur_latch_leaves(
 			get_block->check_index_page_at_flush = TRUE;
 		}
 
-		get_block = btr_block_get(space, zip_size, page_no, mode, mtr);
+		get_block = btr_block_get(
+			space, zip_size, page_no, mode, cursor->index, mtr);
 #ifdef UNIV_BTR_DEBUG
 		ut_a(page_is_comp(get_block->frame) == page_is_comp(page));
 #endif /* UNIV_BTR_DEBUG */
@@ -669,7 +673,9 @@ retry_page_get:
 		ut_a(!page_zip || page_zip_validate(page_zip, page));
 #endif /* UNIV_ZIP_DEBUG */
 
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+		buf_block_dbg_add_level(
+			block, dict_index_is_ibuf(index)
+			? SYNC_IBUF_TREE_NODE : SYNC_TREE_NODE);
 	}
 
 	ut_ad(index->id == btr_page_get_index_id(page));
@@ -767,7 +773,7 @@ retry_page_get:
 	if (level != 0) {
 		/* x-latch the page */
 		page = btr_page_get(
-			space, zip_size, page_no, RW_X_LATCH, mtr);
+			space, zip_size, page_no, RW_X_LATCH, index, mtr);
 
 		ut_a((ibool)!!page_is_comp(page)
 		     == dict_table_is_comp(index->table));
diff --git a/storage/innobase/btr/btr0pcur.c b/storage/innobase/btr/btr0pcur.c
index 056896c7927..3bd2e9fd7d6 100644
--- a/storage/innobase/btr/btr0pcur.c
+++ b/storage/innobase/btr/btr0pcur.c
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1996, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1996, 2011, Oracle and/or its affiliates. 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
@@ -266,8 +266,10 @@ btr_pcur_restore_position_func(
 					file, line, mtr))) {
 			cursor->pos_state = BTR_PCUR_IS_POSITIONED;
 
-			buf_block_dbg_add_level(btr_pcur_get_block(cursor),
-						SYNC_TREE_NODE);
+			buf_block_dbg_add_level(
+				btr_pcur_get_block(cursor),
+				dict_index_is_ibuf(index)
+				? SYNC_IBUF_TREE_NODE : SYNC_TREE_NODE);
 
 			if (cursor->rel_pos == BTR_PCUR_ON) {
 #ifdef UNIV_DEBUG
@@ -417,7 +419,8 @@ btr_pcur_move_to_next_page(
 	ut_ad(next_page_no != FIL_NULL);
 
 	next_block = btr_block_get(space, zip_size, next_page_no,
-				   cursor->latch_mode, mtr);
+				   cursor->latch_mode,
+				   btr_pcur_get_btr_cur(cursor)->index, mtr);
 	next_page = buf_block_get_frame(next_block);
 #ifdef UNIV_BTR_DEBUG
 	ut_a(page_is_comp(next_page) == page_is_comp(page));
diff --git a/storage/innobase/btr/btr0sea.c b/storage/innobase/btr/btr0sea.c
index 93573a300e4..7070420425c 100644
--- a/storage/innobase/btr/btr0sea.c
+++ b/storage/innobase/btr/btr0sea.c
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1996, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 1996, 2011, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, Google Inc.
 
 Portions of this file contain modifications contributed and copyrighted by
@@ -845,6 +845,7 @@ btr_search_guess_on_hash(
 	btr_pcur_t	pcur;
 #endif
 	ut_ad(index && info && tuple && cursor && mtr);
+	ut_ad(!dict_index_is_ibuf(index));
 	ut_ad((latch_mode == BTR_SEARCH_LEAF)
 	      || (latch_mode == BTR_MODIFY_LEAF));
 
diff --git a/storage/innobase/dict/dict0crea.c b/storage/innobase/dict/dict0crea.c
index 9a528d679a7..d7373a4b8ef 100644
--- a/storage/innobase/dict/dict0crea.c
+++ b/storage/innobase/dict/dict0crea.c
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1996, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1996, 2011, Oracle and/or its affiliates. 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
@@ -827,7 +827,7 @@ dict_truncate_index_tree(
 	appropriate field in the SYS_INDEXES record: this mini-transaction
 	marks the B-tree totally truncated */
 
-	btr_block_get(space, zip_size, root_page_no, RW_X_LATCH, mtr);
+	btr_block_get(space, zip_size, root_page_no, RW_X_LATCH, NULL, mtr);
 
 	btr_free_root(space, zip_size, root_page_no, mtr);
 create:
diff --git a/storage/innobase/dict/dict0dict.c b/storage/innobase/dict/dict0dict.c
index 1e3aed92cf7..ead86e37380 100644
--- a/storage/innobase/dict/dict0dict.c
+++ b/storage/innobase/dict/dict0dict.c
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1996, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1996, 2011, Oracle and/or its affiliates. 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
@@ -1714,7 +1714,8 @@ undo_size_ok:
 
 	new_index->page = page_no;
 	rw_lock_create(index_tree_rw_lock_key, &new_index->lock,
-		       SYNC_INDEX_TREE);
+		       dict_index_is_ibuf(index)
+		       ? SYNC_IBUF_INDEX_TREE : SYNC_INDEX_TREE);
 
 	if (!UNIV_UNLIKELY(new_index->type & DICT_UNIVERSAL)) {
 
diff --git a/storage/innobase/ibuf/ibuf0ibuf.c b/storage/innobase/ibuf/ibuf0ibuf.c
index 7d94ebc6438..718f2082ce9 100644
--- a/storage/innobase/ibuf/ibuf0ibuf.c
+++ b/storage/innobase/ibuf/ibuf0ibuf.c
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1997, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1997, 2011, Oracle and/or its affiliates. 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
@@ -402,7 +402,7 @@ ibuf_tree_root_get(
 	block = buf_page_get(
 		IBUF_SPACE_ID, 0, FSP_IBUF_TREE_ROOT_PAGE_NO, RW_X_LATCH, mtr);
 
-	buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+	buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE_NEW);
 
 	root = buf_block_get_frame(block);
 
@@ -549,7 +549,7 @@ ibuf_init_at_db_start(void)
 		block = buf_page_get(
 			IBUF_SPACE_ID, 0, FSP_IBUF_TREE_ROOT_PAGE_NO,
 			RW_X_LATCH, &mtr);
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE);
 
 		root = buf_block_get_frame(block);
 	}
@@ -2209,7 +2209,8 @@ ibuf_add_free_page(void)
 	} else {
 		buf_block_t*	block = buf_page_get(
 			IBUF_SPACE_ID, 0, page_no, RW_X_LATCH, &mtr);
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE_NEW);
+
+		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE_NEW);
 
 		page = buf_block_get_frame(block);
 	}
@@ -2332,8 +2333,7 @@ ibuf_remove_free_page(void)
 		block = buf_page_get(
 			IBUF_SPACE_ID, 0, page_no, RW_X_LATCH, &mtr);
 
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE);
-
+		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE);
 
 		page = buf_block_get_frame(block);
 	}
@@ -3022,7 +3022,7 @@ ibuf_get_volume_buffered(
 			IBUF_SPACE_ID, 0, prev_page_no, RW_X_LATCH,
 			mtr);
 
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE);
 
 
 		prev_page = buf_block_get_frame(block);
@@ -3095,7 +3095,7 @@ count_later:
 			IBUF_SPACE_ID, 0, next_page_no, RW_X_LATCH,
 			mtr);
 
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE);
 
 
 		next_page = buf_block_get_frame(block);
@@ -3333,7 +3333,7 @@ ibuf_set_entry_counter(
 				IBUF_SPACE_ID, 0, prev_page_no,
 				RW_X_LATCH, mtr);
 
-			buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+			buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE);
 
 			prev_page = buf_block_get_frame(block);
 
@@ -4419,6 +4419,7 @@ ibuf_merge_or_delete_for_page(
 	ut_ad(!block || buf_block_get_space(block) == space);
 	ut_ad(!block || buf_block_get_page_no(block) == page_no);
 	ut_ad(!block || buf_block_get_zip_size(block) == zip_size);
+	ut_ad(!block || buf_block_get_io_fix(block) == BUF_IO_READ);
 
 	if (srv_force_recovery >= SRV_FORCE_NO_IBUF_MERGE
 	    || trx_sys_hdr_page(space, page_no)) {
@@ -4571,7 +4572,13 @@ loop:
 
 		ut_a(success);
 
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+		/* This is a user page (secondary index leaf page),
+		but we pretend that it is a change buffer page in
+		order to obey the latching order. This should be OK,
+		because buffered changes are applied immediately while
+		the block is io-fixed. Other threads must not try to
+		latch an io-fixed block. */
+		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE);
 	}
 
 	/* Position pcur in the insert buffer at the first entry for this
@@ -4675,7 +4682,12 @@ loop:
 					__FILE__, __LINE__, &mtr);
 				ut_a(success);
 
-				buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+				/* This is a user page (secondary
+				index leaf page), but it should be OK
+				to use too low latching order for it,
+				as the block is io-fixed. */
+				buf_block_dbg_add_level(
+					block, SYNC_IBUF_TREE_NODE);
 
 				if (!ibuf_restore_pos(space, page_no,
 						      search_tuple,
diff --git a/storage/innobase/include/btr0btr.h b/storage/innobase/include/btr0btr.h
index 24f3801c7f8..699f201fe15 100644
--- a/storage/innobase/include/btr0btr.h
+++ b/storage/innobase/include/btr0btr.h
@@ -199,26 +199,45 @@ btr_block_get_func(
 	ulint		mode,		/*!< in: latch mode */
 	const char*	file,		/*!< in: file name */
 	ulint		line,		/*!< in: line where called */
-	mtr_t*		mtr)		/*!< in/out: mtr */
-	__attribute__((nonnull));
+# ifdef UNIV_SYNC_DEBUG
+	const dict_index_t*	index,	/*!< in: index tree, may be NULL
+					if it is not an insert buffer tree */
+# endif /* UNIV_SYNC_DEBUG */
+	mtr_t*		mtr);		/*!< in/out: mini-transaction */
+# ifdef UNIV_SYNC_DEBUG
 /** Gets a buffer page and declares its latching order level.
 @param space	tablespace identifier
 @param zip_size	compressed page size in bytes or 0 for uncompressed pages
 @param page_no	page number
 @param mode	latch mode
+@param index	index tree, may be NULL if not the insert buffer tree
 @param mtr	mini-transaction handle
 @return the block descriptor */
-# define btr_block_get(space,zip_size,page_no,mode,mtr) \
-	btr_block_get_func(space,zip_size,page_no,mode,__FILE__,__LINE__,mtr)
+#  define btr_block_get(space,zip_size,page_no,mode,index,mtr)	\
+	btr_block_get_func(space,zip_size,page_no,mode,		\
+			   __FILE__,__LINE__,index,mtr)
+# else /* UNIV_SYNC_DEBUG */
 /** Gets a buffer page and declares its latching order level.
 @param space	tablespace identifier
 @param zip_size	compressed page size in bytes or 0 for uncompressed pages
 @param page_no	page number
 @param mode	latch mode
+@param idx	index tree, may be NULL if not the insert buffer tree
+@param mtr	mini-transaction handle
+@return the block descriptor */
+#  define btr_block_get(space,zip_size,page_no,mode,idx,mtr)		\
+	btr_block_get_func(space,zip_size,page_no,mode,__FILE__,__LINE__,mtr)
+# endif /* UNIV_SYNC_DEBUG */
+/** Gets a buffer page and declares its latching order level.
+@param space	tablespace identifier
+@param zip_size	compressed page size in bytes or 0 for uncompressed pages
+@param page_no	page number
+@param mode	latch mode
+@param idx	index tree, may be NULL if not the insert buffer tree
 @param mtr	mini-transaction handle
 @return the uncompressed page frame */
-# define btr_page_get(space,zip_size,page_no,mode,mtr) \
-	buf_block_get_frame(btr_block_get(space,zip_size,page_no,mode,mtr))
+# define btr_page_get(space,zip_size,page_no,mode,idx,mtr)		\
+	buf_block_get_frame(btr_block_get(space,zip_size,page_no,mode,idx,mtr))
 #endif /* !UNIV_HOTBACKUP */
 /**************************************************************//**
 Gets the index id field of a page.
@@ -344,8 +363,7 @@ btr_free_root(
 	ulint	zip_size,	/*!< in: compressed page size in bytes
 				or 0 for uncompressed pages */
 	ulint	root_page_no,	/*!< in: root page number */
-	mtr_t*	mtr);		/*!< in: a mini-transaction which has already
-				been started */
+	mtr_t*	mtr);		/*!< in/out: mini-transaction */
 /*************************************************************//**
 Makes tree one level higher by splitting the root, and inserts
 the tuple. It is assumed that mtr contains an x-latch on the tree.
diff --git a/storage/innobase/include/btr0btr.ic b/storage/innobase/include/btr0btr.ic
index ccf41904fd0..1bd22a0ebc6 100644
--- a/storage/innobase/include/btr0btr.ic
+++ b/storage/innobase/include/btr0btr.ic
@@ -1,6 +1,6 @@
 /*****************************************************************************
 
-Copyright (c) 1994, 2010, Innobase Oy. All Rights Reserved.
+Copyright (c) 1994, 2011, Oracle and/or its affiliates. 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
@@ -48,6 +48,10 @@ btr_block_get_func(
 	ulint		mode,		/*!< in: latch mode */
 	const char*	file,		/*!< in: file name */
 	ulint		line,		/*!< in: line where called */
+#ifdef UNIV_SYNC_DEBUG
+	const dict_index_t*	index,	/*!< in: index tree, may be NULL
+					if it is not an insert buffer tree */
+#endif /* UNIV_SYNC_DEBUG */
 	mtr_t*		mtr)		/*!< in/out: mtr */
 {
 	buf_block_t*	block;
@@ -57,7 +61,9 @@ btr_block_get_func(
 
 	if (mode != RW_NO_LATCH) {
 
-		buf_block_dbg_add_level(block, SYNC_TREE_NODE);
+		buf_block_dbg_add_level(
+			block, index != NULL && dict_index_is_ibuf(index)
+			? SYNC_IBUF_TREE_NODE : SYNC_TREE_NODE);
 	}
 
 	return(block);
diff --git a/storage/innobase/include/sync0sync.h b/storage/innobase/include/sync0sync.h
index dd74ccee523..9c0d5e3c302 100644
--- a/storage/innobase/include/sync0sync.h
+++ b/storage/innobase/include/sync0sync.h
@@ -638,10 +638,6 @@ or row lock! */
 #define SYNC_DICT_HEADER	995
 #define SYNC_IBUF_HEADER	914
 #define SYNC_IBUF_PESS_INSERT_MUTEX 912
-#define SYNC_IBUF_MUTEX		910	/* ibuf mutex is really below
-					SYNC_FSP_PAGE: we assign a value this
-					high only to make the program to pass
-					the debug checks */
 /*-------------------------------*/
 #define	SYNC_INDEX_TREE		900
 #define SYNC_TREE_NODE_NEW	892
@@ -657,8 +653,11 @@ or row lock! */
 #define	SYNC_FSP		400
 #define	SYNC_FSP_PAGE		395
 /*------------------------------------- Insert buffer headers */
-/*------------------------------------- ibuf_mutex */
+#define SYNC_IBUF_MUTEX		370	/* ibuf_mutex */
 /*------------------------------------- Insert buffer tree */
+#define SYNC_IBUF_INDEX_TREE	360
+#define SYNC_IBUF_TREE_NODE_NEW	359
+#define SYNC_IBUF_TREE_NODE	358
 #define	SYNC_IBUF_BITMAP_MUTEX	351
 #define	SYNC_IBUF_BITMAP	350
 /*------------------------------------- MySQL query cache mutex */
diff --git a/storage/innobase/sync/sync0sync.c b/storage/innobase/sync/sync0sync.c
index 251a392a02c..3888fe4c657 100644
--- a/storage/innobase/sync/sync0sync.c
+++ b/storage/innobase/sync/sync0sync.c
@@ -1232,6 +1232,7 @@ sync_thread_add_level(
 	case SYNC_DICT_HEADER:
 	case SYNC_TRX_I_S_RWLOCK:
 	case SYNC_TRX_I_S_LAST_READ:
+	case SYNC_IBUF_MUTEX:
 		if (!sync_thread_levels_g(array, level, TRUE)) {
 			fprintf(stderr,
 				"InnoDB: sync_thread_levels_g(array, %lu)"
@@ -1317,21 +1318,27 @@ sync_thread_add_level(
 		     || sync_thread_levels_g(array, SYNC_TREE_NODE - 1, TRUE));
 		break;
 	case SYNC_TREE_NODE_NEW:
-		ut_a(sync_thread_levels_contain(array, SYNC_FSP_PAGE)
-		     || sync_thread_levels_contain(array, SYNC_IBUF_MUTEX));
+		ut_a(sync_thread_levels_contain(array, SYNC_FSP_PAGE));
 		break;
 	case SYNC_INDEX_TREE:
-		if (sync_thread_levels_contain(array, SYNC_IBUF_MUTEX)
-		    && sync_thread_levels_contain(array, SYNC_FSP)) {
-			ut_a(sync_thread_levels_g(array, SYNC_FSP_PAGE - 1,
-						  TRUE));
-		} else {
-			ut_a(sync_thread_levels_g(array, SYNC_TREE_NODE - 1,
-						  TRUE));
-		}
+		ut_a(sync_thread_levels_g(array, SYNC_TREE_NODE - 1, TRUE));
 		break;
-	case SYNC_IBUF_MUTEX:
-		ut_a(sync_thread_levels_g(array, SYNC_FSP_PAGE - 1, TRUE));
+	case SYNC_IBUF_TREE_NODE:
+		ut_a(sync_thread_levels_contain(array, SYNC_IBUF_INDEX_TREE)
+		     || sync_thread_levels_g(array, SYNC_IBUF_TREE_NODE - 1,
+					     TRUE));
+		break;
+	case SYNC_IBUF_TREE_NODE_NEW:
+		ut_a(sync_thread_levels_contain(array, SYNC_IBUF_MUTEX));
+		break;
+	case SYNC_IBUF_INDEX_TREE:
+		if (sync_thread_levels_contain(array, SYNC_FSP)) {
+			ut_a(sync_thread_levels_g(
+				     array, SYNC_FSP_PAGE - 1, TRUE));
+		} else {
+			ut_a(sync_thread_levels_g(
+				     array, SYNC_IBUF_TREE_NODE - 1, TRUE));
+		}
 		break;
 	case SYNC_IBUF_PESS_INSERT_MUTEX:
 		ut_a(sync_thread_levels_g(array, SYNC_FSP - 1, TRUE));