diff --git a/storage/xtradb/btr/btr0cur.c b/storage/xtradb/btr/btr0cur.c
index 73947fd8db8..32bef340a1b 100644
--- a/storage/xtradb/btr/btr0cur.c
+++ b/storage/xtradb/btr/btr0cur.c
@@ -4428,7 +4428,7 @@ btr_blob_free(
 	    && buf_block_get_space(block) == space
 	    && buf_block_get_page_no(block) == page_no) {
 
-		if (!buf_LRU_free_block(&block->page, (void *)&block->mutex, all, &have_LRU_mutex)
+		if (!buf_LRU_free_block(&block->page, all, TRUE)
 		    && all && block->page.zip.data
 		    /* Now, buf_LRU_free_block() may release mutex temporarily */
 		    && buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE
@@ -4437,7 +4437,7 @@ btr_blob_free(
 			/* Attempt to deallocate the uncompressed page
 			if the whole block cannot be deallocted. */
 
-			buf_LRU_free_block(&block->page, (void *)&block->mutex, FALSE, &have_LRU_mutex);
+			buf_LRU_free_block(&block->page, FALSE, TRUE);
 		}
 	}
 
diff --git a/storage/xtradb/buf/buf0buf.c b/storage/xtradb/buf/buf0buf.c
index 1c1086cde5c..803d3a66c54 100644
--- a/storage/xtradb/buf/buf0buf.c
+++ b/storage/xtradb/buf/buf0buf.c
@@ -1600,6 +1600,12 @@ buf_pool_watch_is_sentinel(
 	buf_pool_t*		buf_pool,	/*!< buffer pool instance */
 	const buf_page_t*	bpage)		/*!< in: block */
 {
+#ifdef UNIV_SYNC_DEBUG
+	ut_ad(rw_lock_own(&buf_pool->page_hash_latch, RW_LOCK_SHARED)
+	      || rw_lock_own(&buf_pool->page_hash_latch, RW_LOCK_EX)
+	      || mutex_own(buf_page_get_mutex(bpage)));
+#endif
+
 	ut_ad(buf_page_in_file(bpage));
 
 	if (bpage < &buf_pool->watch[0]
@@ -1976,7 +1982,6 @@ buf_page_get_zip(
 	ib_uint64_t	start_time;
 	ib_uint64_t	finish_time;
 	buf_pool_t*	buf_pool = buf_pool_get(space, offset);
-	ibool have_LRU_mutex = FALSE;
 
 	if (UNIV_UNLIKELY(innobase_get_slow_log())) {
 		trx = innobase_get_trx();
@@ -2048,40 +2053,33 @@ err_exit:
 		mutex_exit(block_mutex);
 
 		/* get LRU_list_mutex for buf_LRU_free_block() */
-		if (!have_LRU_mutex) {
-			mutex_enter(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = TRUE;
-		}
-
+		ut_ad(!mutex_own(&buf_pool->LRU_list_mutex));
+		mutex_enter(&buf_pool->LRU_list_mutex);
 		mutex_enter(block_mutex);
 
-		if (UNIV_UNLIKELY(bpage->space != space
+		if (UNIV_UNLIKELY((buf_page_get_state(bpage)
+				   != BUF_BLOCK_FILE_PAGE)
+				  || bpage->space != space
 				  || bpage->offset != offset
 				  || !bpage->in_LRU_list
 				  || !bpage->zip.data)) {
 			/* someone should interrupt, retry */
-			if (have_LRU_mutex) {
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				have_LRU_mutex = FALSE;
-			}
+			ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
+			mutex_exit(&buf_pool->LRU_list_mutex);
 			mutex_exit(block_mutex);
 			goto lookup;
 		}
 
 		/* Discard the uncompressed page frame if possible. */
-		if (buf_LRU_free_block(bpage, (void *)block_mutex, FALSE, &have_LRU_mutex)) {
-			if (have_LRU_mutex) {
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				have_LRU_mutex = FALSE;
-			}
+		if (buf_LRU_free_block(bpage, FALSE, TRUE)) {
+			ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
+			mutex_exit(&buf_pool->LRU_list_mutex);
 			mutex_exit(block_mutex);
 			goto lookup;
 		}
 
-		if (have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = FALSE;
-		}
+		ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
+		mutex_exit(&buf_pool->LRU_list_mutex);
 
 		buf_block_buf_fix_inc((buf_block_t*) bpage,
 				      __FILE__, __LINE__);
@@ -2464,7 +2462,6 @@ buf_page_get_gen(
 	ib_uint64_t	start_time;
 	ib_uint64_t	finish_time;
 	buf_pool_t*	buf_pool = buf_pool_get(space, offset);
-	ibool           have_LRU_mutex = FALSE;
 
 	ut_ad(mtr);
 	ut_ad(mtr->state == MTR_ACTIVE);
@@ -2566,21 +2563,9 @@ loop2:
 		    || mode == BUF_PEEK_IF_IN_POOL
 		    || mode == BUF_GET_IF_IN_POOL_OR_WATCH) {
 
-			if (have_LRU_mutex) {
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				have_LRU_mutex = FALSE;
-			}
-
 			return(NULL);
 		}
 
-		/* We should not hold LRU mutex below when trying
-		to read the page */
-		if (have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = FALSE;
-		}
-
 		if (buf_read_page(space, zip_size, offset, trx)) {
 			buf_read_ahead_random(space, zip_size, offset,
 					      ibuf_inside(mtr), trx);
@@ -2633,11 +2618,6 @@ null_exit:
 		//buf_pool_mutex_exit(buf_pool);
 		mutex_exit(block_mutex);
 
-		if (have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = FALSE;
-		}
-
 		return(NULL);
 	}
 
@@ -2646,11 +2626,6 @@ null_exit:
 
 		mutex_exit(block_mutex);
 
-		if (have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = FALSE;
-		}
-
 		return(NULL);
 	}
 
@@ -2711,12 +2686,8 @@ wait_until_unfixed:
 		ut_a(block);
 		block_mutex = &block->mutex;
 
-		//buf_pool_mutex_enter(buf_pool);
-		if (!have_LRU_mutex) {
-			mutex_enter(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = TRUE;
-		}
-
+		ut_ad(!mutex_own(&buf_pool->LRU_list_mutex));
+		mutex_enter(&buf_pool->LRU_list_mutex);
 		rw_lock_x_lock(&buf_pool->page_hash_latch);
 		mutex_enter(&block->mutex);
 		mutex_enter(&buf_pool->zip_mutex);
@@ -2740,10 +2711,8 @@ wait_until_unfixed:
 
 			rw_lock_x_unlock(&buf_pool->page_hash_latch);
 
-			if (have_LRU_mutex) {
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				have_LRU_mutex = FALSE;
-			}
+			ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
+			mutex_exit(&buf_pool->LRU_list_mutex);
 
 			goto wait_until_unfixed;
 		}
@@ -2782,10 +2751,8 @@ wait_until_unfixed:
 		/* Insert at the front of unzip_LRU list */
 		buf_unzip_LRU_add_block(block, FALSE);
 
-		if (have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = FALSE;
-		}
+		ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
+		mutex_exit(&buf_pool->LRU_list_mutex);
 
 		block->page.buf_fix_count = 1;
 		buf_block_set_io_fix(block, BUF_IO_READ);
@@ -2859,12 +2826,7 @@ wait_until_unfixed:
 		insert buffer (change buffer) as much as possible. */
 		ulint	page_no	= buf_block_get_page_no(block);
 
-		if (!have_LRU_mutex) {
-			mutex_enter(&buf_pool->LRU_list_mutex);
-			have_LRU_mutex = TRUE;
-		}
-
-		if (buf_LRU_free_block(&block->page, (void *)block_mutex, TRUE, &have_LRU_mutex)) {
+		if (buf_LRU_free_block(&block->page, TRUE, FALSE)) {
 			mutex_exit(block_mutex);
 			if (mode == BUF_GET_IF_IN_POOL_OR_WATCH) {
 				/* Set the watch, as it would have
@@ -2889,11 +2851,6 @@ wait_until_unfixed:
 				"innodb_change_buffering_debug evict %u %u\n",
 				(unsigned) space, (unsigned) offset);
 
-			if (have_LRU_mutex){
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				have_LRU_mutex = FALSE;
-			}
-
 			return(NULL);
 		} else if (UNIV_UNLIKELY(buf_block_get_state(block)
 					 != BUF_BLOCK_FILE_PAGE
@@ -2910,10 +2867,7 @@ wait_until_unfixed:
 		} else {
 			/* We should not hold LRU mutex below when trying
 			to flush page */
-			if (have_LRU_mutex) {
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				have_LRU_mutex = FALSE;
-			}
+			ut_ad(!mutex_own(&buf_pool->LRU_list_mutex));
 
 			if (buf_flush_page_try(buf_pool, block)) {
 				fprintf(stderr,
@@ -3022,11 +2976,6 @@ wait_until_unfixed:
 		_increment_page_get_statistics(block, trx);
 	}
 
-	if (have_LRU_mutex) {
-		mutex_exit(&buf_pool->LRU_list_mutex);
-		have_LRU_mutex = FALSE;
-	}
-
 	return(block);
 }
 
diff --git a/storage/xtradb/buf/buf0flu.c b/storage/xtradb/buf/buf0flu.c
index dda0630c09a..0afdeb3fd02 100644
--- a/storage/xtradb/buf/buf0flu.c
+++ b/storage/xtradb/buf/buf0flu.c
@@ -1606,7 +1606,11 @@ buf_flush_page_and_try_neighbors(
 	}
 
 	ut_a(buf_page_in_file(bpage)
-	     || buf_page_get_state(bpage) == BUF_BLOCK_REMOVE_HASH);
+	     || (buf_page_get_state(bpage) == BUF_BLOCK_REMOVE_HASH
+#ifdef UNIV_DEBUG
+		 && !mutex_own(&buf_pool->LRU_list_mutex)
+#endif
+		 ));
 
 	if (buf_flush_ready_for_flush(bpage, flush_type)) {
 		ulint		space;
diff --git a/storage/xtradb/buf/buf0lru.c b/storage/xtradb/buf/buf0lru.c
index 7156068ccc5..8b74fd10c3d 100644
--- a/storage/xtradb/buf/buf0lru.c
+++ b/storage/xtradb/buf/buf0lru.c
@@ -177,24 +177,15 @@ UNIV_INLINE
 ibool
 buf_LRU_evict_from_unzip_LRU(
 /*=========================*/
-	buf_pool_t*	buf_pool,
-	ibool*		have_LRU_mutex)
+	buf_pool_t*	buf_pool)
 {
 	ulint	io_avg;
 	ulint	unzip_avg;
 
-	//ut_ad(buf_pool_mutex_own(buf_pool));
+	ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
 
-	if (!*have_LRU_mutex) {
-		mutex_enter(&buf_pool->LRU_list_mutex);
-		*have_LRU_mutex = TRUE;
-	}
 	/* If the unzip_LRU list is empty, we can only use the LRU. */
 	if (UT_LIST_GET_LEN(buf_pool->unzip_LRU) == 0) {
-		if (*have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = FALSE;
-		}
 		return(FALSE);
 	}
 
@@ -203,26 +194,14 @@ buf_LRU_evict_from_unzip_LRU(
 	decompressed pages in the buffer pool. */
 	if (UT_LIST_GET_LEN(buf_pool->unzip_LRU)
 	    <= UT_LIST_GET_LEN(buf_pool->LRU) / 10) {
-		if (*have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = FALSE;
-		}
 		return(FALSE);
 	}
 
 	/* If eviction hasn't started yet, we assume by default
 	that a workload is disk bound. */
 	if (buf_pool->freed_page_clock == 0) {
-		if (*have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = FALSE;
-		}
 		return(TRUE);
 	}
-	if (*have_LRU_mutex) {
-		mutex_exit(&buf_pool->LRU_list_mutex);
-		*have_LRU_mutex = FALSE;
-	}
 
 	/* Calculate the average over past intervals, and add the values
 	of the current interval. */
@@ -626,6 +605,8 @@ buf_flush_or_remove_pages(
 	ibool		all_freed = TRUE;
 	ibool		must_restart = FALSE;
 
+	ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
+
 	buf_flush_list_mutex_enter(buf_pool);
 
 	for (bpage = UT_LIST_GET_LAST(buf_pool->flush_list);
@@ -946,20 +927,18 @@ ibool
 buf_LRU_free_from_unzip_LRU_list(
 /*=============================*/
 	buf_pool_t*	buf_pool,	/*!< in: buffer pool instance */
-	ulint		n_iterations,	/*!< in: how many times this has
+	ulint		n_iterations)	/*!< in: how many times this has
 					been called repeatedly without
 					result: a high value means that
 					we should search farther; we will
 					search n_iterations / 5 of the
 					unzip_LRU list, or nothing if
 					n_iterations >= 5 */
-	ibool*		have_LRU_mutex)
 {
 	buf_block_t*	block;
 	ulint		distance;
-	ibool		taken_LRU_mutex = FALSE;
 
-	//ut_ad(buf_pool_mutex_own(buf_pool));
+	ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
 
 	/* Theoratically it should be much easier to find a victim
 	from unzip_LRU as we can choose even a dirty block (as we'll
@@ -969,7 +948,7 @@ buf_LRU_free_from_unzip_LRU_list(
 	if we have done five iterations so far. */
 
 	if (UNIV_UNLIKELY(n_iterations >= 5)
-	    || !buf_LRU_evict_from_unzip_LRU(buf_pool, have_LRU_mutex)) {
+	    || !buf_LRU_evict_from_unzip_LRU(buf_pool)) {
 
 		return(FALSE);
 	}
@@ -977,54 +956,25 @@ buf_LRU_free_from_unzip_LRU_list(
 	distance = 100 + (n_iterations
 			  * UT_LIST_GET_LEN(buf_pool->unzip_LRU)) / 5;
 
-	if (!*have_LRU_mutex) {
-		mutex_enter(&buf_pool->LRU_list_mutex);
-		taken_LRU_mutex = TRUE;
-		*have_LRU_mutex = TRUE;
-	}
-
-restart:
 	for (block = UT_LIST_GET_LAST(buf_pool->unzip_LRU);
 	     UNIV_LIKELY(block != NULL) && UNIV_LIKELY(distance > 0);
 	     block = UT_LIST_GET_PREV(unzip_LRU, block), distance--) {
 
 		ibool freed;
 
-		mutex_enter(&block->mutex);
-		if (!block->in_unzip_LRU_list || !block->page.in_LRU_list
-		    || buf_block_get_state(block) != BUF_BLOCK_FILE_PAGE) {
-			mutex_exit(&block->mutex);
-			goto restart;
-		}
-
-		ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
-		ut_a(block->page.buf_pool_index < srv_buf_pool_instances);
 		ut_ad(buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE);
 		ut_ad(block->in_unzip_LRU_list);
 		ut_ad(block->page.in_LRU_list);
 
-		freed = buf_LRU_free_block(&block->page, (void *)&block->mutex, FALSE, have_LRU_mutex);
+		mutex_enter(&block->mutex);
+		freed = buf_LRU_free_block(&block->page, FALSE, TRUE);
 		mutex_exit(&block->mutex);
 
 		if (freed) {
-
-			if (taken_LRU_mutex && *have_LRU_mutex) {
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				*have_LRU_mutex = FALSE;
-			}
 			return(TRUE);
-		} else if (!*have_LRU_mutex) {
-			*have_LRU_mutex = TRUE;
-			mutex_enter(&buf_pool->LRU_list_mutex);
-			taken_LRU_mutex = TRUE;
 		}
 	}
 
-	if (taken_LRU_mutex && *have_LRU_mutex) {
-		mutex_exit(&buf_pool->LRU_list_mutex);
-		*have_LRU_mutex = FALSE;
-	}
-
 	return(FALSE);
 }
 
@@ -1036,55 +986,37 @@ ibool
 buf_LRU_free_from_common_LRU_list(
 /*==============================*/
 	buf_pool_t*	buf_pool,
-	ulint		n_iterations,
+	ulint		n_iterations)
 				/*!< in: how many times this has been called
 				repeatedly without result: a high value means
 				that we should search farther; if
 				n_iterations < 10, then we search
 				n_iterations / 10 * buf_pool->curr_size
 				pages from the end of the LRU list */
-	ibool*		have_LRU_mutex)
 {
 	buf_page_t*	bpage;
 	ulint		distance;
-	ibool		taken_LRU_mutex = FALSE;
 
-	//ut_ad(buf_pool_mutex_own(buf_pool));
+	ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
 
 	distance = 100 + (n_iterations * buf_pool->curr_size) / 10;
 
-	if (!*have_LRU_mutex) {
-		mutex_enter(&buf_pool->LRU_list_mutex);
-		taken_LRU_mutex = TRUE;
-		*have_LRU_mutex = TRUE;
-	}
-
-restart:
 	for (bpage = UT_LIST_GET_LAST(buf_pool->LRU);
 	     UNIV_LIKELY(bpage != NULL) && UNIV_LIKELY(distance > 0);
 	     bpage = UT_LIST_GET_PREV(LRU, bpage), distance--) {
 
 		ibool		freed;
 		unsigned	accessed;
-		mutex_t*	block_mutex = buf_page_get_mutex_enter(bpage);
-
-		if (!block_mutex) {
-			goto restart;
-		}
-
-		if (!bpage->in_LRU_list
-		    || !buf_page_in_file(bpage)) {
-			mutex_exit(block_mutex);
-			goto restart;
-		}
+		mutex_t*	block_mutex = buf_page_get_mutex(bpage);
 
 		ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
 		ut_ad(buf_page_in_file(bpage));
 		ut_ad(bpage->in_LRU_list);
 		ut_a(bpage->buf_pool_index < srv_buf_pool_instances);
 
+		mutex_enter(block_mutex);
 		accessed = buf_page_is_accessed(bpage);
-		freed = buf_LRU_free_block(bpage, (void *)block_mutex, TRUE, have_LRU_mutex);
+		freed = buf_LRU_free_block(bpage, TRUE, TRUE);
 		mutex_exit(block_mutex);
 
 		if (freed) {
@@ -1095,24 +1027,10 @@ restart:
 				++buf_pool->stat.n_ra_pages_evicted;
 			}
 
-			if (taken_LRU_mutex && *have_LRU_mutex) {
-				mutex_exit(&buf_pool->LRU_list_mutex);
-				*have_LRU_mutex = FALSE;
-			}
-
 			return(TRUE);
-		} else if (!*have_LRU_mutex) {
-			mutex_enter(&buf_pool->LRU_list_mutex);
-			taken_LRU_mutex = TRUE;
-			*have_LRU_mutex = TRUE;
 		}
 	}
 
-	if (taken_LRU_mutex && *have_LRU_mutex) {
-		mutex_exit(&buf_pool->LRU_list_mutex);
-		*have_LRU_mutex = FALSE;
-	}
-
 	return(FALSE);
 }
 
@@ -1136,23 +1054,19 @@ buf_LRU_search_and_free_block(
 				n_iterations / 5 of the unzip_LRU list. */
 {
 	ibool	freed = FALSE;
-	ibool	have_LRU_mutex = FALSE;
 
-	//buf_pool_mutex_enter(buf_pool);
-	if (UT_LIST_GET_LEN(buf_pool->unzip_LRU)) {
-		ut_ad(!mutex_own(&buf_pool->LRU_list_mutex));
-		mutex_enter(&buf_pool->LRU_list_mutex);
-		have_LRU_mutex = TRUE;
-	}
+	mutex_enter(&buf_pool->LRU_list_mutex);
 
-	freed = buf_LRU_free_from_unzip_LRU_list(buf_pool, n_iterations, &have_LRU_mutex);
+	freed = buf_LRU_free_from_unzip_LRU_list(buf_pool, n_iterations);
 
 	if (!freed) {
+		ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
 		freed = buf_LRU_free_from_common_LRU_list(
-			buf_pool, n_iterations, &have_LRU_mutex);
+			buf_pool, n_iterations);
 	}
 
 	buf_pool_mutex_enter(buf_pool);
+
 	if (!freed) {
 		buf_pool->LRU_flush_ended = 0;
 	} else if (buf_pool->LRU_flush_ended > 0) {
@@ -1160,8 +1074,8 @@ buf_LRU_search_and_free_block(
 	}
 
 	buf_pool_mutex_exit(buf_pool);
-	if (have_LRU_mutex)
-		mutex_exit(&buf_pool->LRU_list_mutex);
+
+	mutex_exit(&buf_pool->LRU_list_mutex);
 
 	return(freed);
 }
@@ -1893,17 +1807,16 @@ ibool
 buf_LRU_free_block(
 /*===============*/
 	buf_page_t*	bpage,	/*!< in: block to be freed */
-	void*		block_mutex, /*!< in: block mutex or NULL */
 	ibool		zip,	/*!< in: TRUE if should remove also the
 				compressed page of an uncompressed page */
-	ibool*		have_LRU_mutex)
+	ibool		have_LRU_mutex)
 {
 	buf_page_t*	b = NULL;
 	buf_pool_t*	buf_pool = buf_pool_from_bpage(bpage);
-	//mutex_t*	block_mutex = buf_page_get_mutex(bpage);
+	mutex_t*	block_mutex = buf_page_get_mutex(bpage);
 
 	//ut_ad(buf_pool_mutex_own(buf_pool));
-	ut_ad(mutex_own((mutex_t*)block_mutex));
+	ut_ad(mutex_own(block_mutex));
 	ut_ad(buf_page_in_file(bpage));
 	//ut_ad(bpage->in_LRU_list);
 	ut_ad(!bpage->in_flush_list == !bpage->oldest_modification);
@@ -1960,15 +1873,12 @@ alloc:
 #endif /* UNIV_DEBUG */
 
 	/* not to break latch order, must re-enter block_mutex */
-	mutex_exit((mutex_t*)block_mutex);
-
-	if (!*have_LRU_mutex) {
-		mutex_enter(&buf_pool->LRU_list_mutex);
-		*have_LRU_mutex = TRUE;
-	}
+	mutex_exit(block_mutex);
 
+	if (!have_LRU_mutex)
+		mutex_enter(&buf_pool->LRU_list_mutex); /* optimistic */
 	rw_lock_x_lock(&buf_pool->page_hash_latch);
-	mutex_enter((mutex_t*)block_mutex);
+	mutex_enter(block_mutex);
 
 	/* recheck states of block */
 	if (!bpage->in_LRU_list || block_mutex != buf_page_get_mutex(bpage)
@@ -1977,12 +1887,8 @@ not_freed:
 		if (b) {
 			buf_page_free_descriptor(b);
 		}
-
-		if (*have_LRU_mutex) {
+		if (!have_LRU_mutex)
 			mutex_exit(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = FALSE;
-		}
-
 		rw_lock_x_unlock(&buf_pool->page_hash_latch);
 		return(FALSE);
 	} else if (zip || !bpage->zip.data) {
@@ -2117,14 +2023,9 @@ not_freed:
 		}
 
 		//buf_pool_mutex_exit(buf_pool);
-
-		if (*have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = FALSE;
-		}
-
+		mutex_exit(&buf_pool->LRU_list_mutex);
 		rw_lock_x_unlock(&buf_pool->page_hash_latch);
-		mutex_exit((mutex_t*)block_mutex);
+		mutex_exit(block_mutex);
 
 		/* Remove possible adaptive hash index on the page.
 		The page was declared uninitialized by
@@ -2156,13 +2057,9 @@ not_freed:
 		}
 
 		//buf_pool_mutex_enter(buf_pool);
-
-		if (!*have_LRU_mutex) {
+		if (have_LRU_mutex)
 			mutex_enter(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = TRUE;
-		}
-
-		mutex_enter((mutex_t*)block_mutex);
+		mutex_enter(block_mutex);
 
 		if (b) {
 			mutex_enter(&buf_pool->zip_mutex);
@@ -2171,23 +2068,15 @@ not_freed:
 		}
 
 		buf_LRU_block_free_hashed_page((buf_block_t*) bpage, FALSE);
-
-		if (*have_LRU_mutex) {
-			mutex_exit(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = FALSE;
-		}
 	} else {
 		/* The block_mutex should have been released by
 		buf_LRU_block_remove_hashed_page() when it returns
 		BUF_BLOCK_ZIP_FREE. */
-		ut_ad((mutex_t*)block_mutex == &buf_pool->zip_mutex);
-		mutex_enter((mutex_t*)block_mutex);
+		ut_ad(block_mutex == &buf_pool->zip_mutex);
+		mutex_enter(block_mutex);
 
-		if (*have_LRU_mutex) {
+		if (!have_LRU_mutex)
 			mutex_exit(&buf_pool->LRU_list_mutex);
-			*have_LRU_mutex = FALSE;
-		}
-
 		rw_lock_x_unlock(&buf_pool->page_hash_latch);
 	}
 
diff --git a/storage/xtradb/buf/buf0rea.c b/storage/xtradb/buf/buf0rea.c
index 44db27cf943..e4e6415c341 100644
--- a/storage/xtradb/buf/buf0rea.c
+++ b/storage/xtradb/buf/buf0rea.c
@@ -340,9 +340,13 @@ buf_read_ahead_random(
 		return(0);
 	}
 
+	buf_pool_mutex_exit(buf_pool);
+
 	/* Count how many blocks in the area have been recently accessed,
 	that is, reside near the start of the LRU list. */
 
+	rw_lock_s_lock(&buf_pool->page_hash_latch);
+
 	for (i = low; i < high; i++) {
 		const buf_page_t* bpage =
 			buf_page_hash_get(buf_pool, space, i);
@@ -356,13 +360,13 @@ buf_read_ahead_random(
 			if (recent_blocks
 			    >= BUF_READ_AHEAD_RANDOM_THRESHOLD(buf_pool)) {
 
-				buf_pool_mutex_exit(buf_pool);
+				rw_lock_s_unlock(&buf_pool->page_hash_latch);
 				goto read_ahead;
 			}
 		}
 	}
 
-	buf_pool_mutex_exit(buf_pool);
+	rw_lock_s_unlock(&buf_pool->page_hash_latch);
 	/* Do nothing */
 	return(0);
 
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index 510292fefc5..245491a9194 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -12693,9 +12693,9 @@ innodb_buffer_pool_evict_update(
 
 			for (ulint i = 0; i < srv_buf_pool_instances; i++) {
 				buf_pool_t*	buf_pool = &buf_pool_ptr[i];
-				ibool have_LRU_mutex = TRUE;
 
 				//buf_pool_mutex_enter(buf_pool);
+				ut_ad(!mutex_own(&buf_pool->LRU_list_mutex));
 				mutex_enter(&buf_pool->LRU_list_mutex);
 
 				for (buf_block_t* block = UT_LIST_GET_LAST(
@@ -12711,15 +12711,15 @@ innodb_buffer_pool_evict_update(
 					ut_ad(block->page.in_LRU_list);
 
 					mutex_enter(&block->mutex);
+					ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
 					buf_LRU_free_block(&block->page,
-						(void *)&block->mutex,FALSE, &have_LRU_mutex);
+						           FALSE, TRUE);
 					mutex_exit(&block->mutex);
 					block = prev_block;
 				}
 
-				if (have_LRU_mutex) {
-					mutex_exit(&buf_pool->LRU_list_mutex);
-				}
+				ut_ad(mutex_own(&buf_pool->LRU_list_mutex));
+				mutex_exit(&buf_pool->LRU_list_mutex);
 				//buf_pool_mutex_exit(buf_pool);
 			}
 		}
diff --git a/storage/xtradb/include/buf0buf.ic b/storage/xtradb/include/buf0buf.ic
index 7fd32e4e995..1d7924843b9 100644
--- a/storage/xtradb/include/buf0buf.ic
+++ b/storage/xtradb/include/buf0buf.ic
@@ -689,6 +689,11 @@ buf_page_get_block(
 /*===============*/
 	buf_page_t*	bpage)	/*!< in: control block, or NULL */
 {
+#ifdef UNIV_SYNC_DEBUG
+	buf_pool_t*	buf_pool = buf_pool_from_bpage(bpage);
+	ut_ad(rw_lock_own(&buf_pool->page_hash_latch, RW_LOCK_SHARED)
+	      || rw_lock_own(&buf_pool->page_hash_latch, RW_LOCK_EX));
+#endif
 	if (UNIV_LIKELY(bpage != NULL)) {
 		ut_ad(buf_page_in_file(bpage));
 
diff --git a/storage/xtradb/include/buf0lru.h b/storage/xtradb/include/buf0lru.h
index 00988f0957a..2c845e6fbc4 100644
--- a/storage/xtradb/include/buf0lru.h
+++ b/storage/xtradb/include/buf0lru.h
@@ -99,10 +99,9 @@ ibool
 buf_LRU_free_block(
 /*===============*/
 	buf_page_t*	bpage,	/*!< in: block to be freed */
-	void*		block_mutex, /*!< in: block mutex or NULL */
 	ibool		zip,	/*!< in: TRUE if should remove also the
 				compressed page of an uncompressed page */
-	ibool*		have_LRU_mutex)
+	ibool		have_LRU_mutex)
 	__attribute__((nonnull));
 /******************************************************************//**
 Try to free a replaceable block.
diff --git a/storage/xtradb/include/univ.i b/storage/xtradb/include/univ.i
index e9ea4695c87..ca5f57808bd 100644
--- a/storage/xtradb/include/univ.i
+++ b/storage/xtradb/include/univ.i
@@ -64,10 +64,10 @@ component, i.e. we show M.N.P as M.N */
 	(INNODB_VERSION_MAJOR << 8 | INNODB_VERSION_MINOR)
 
 #ifndef PERCONA_INNODB_VERSION
-#define PERCONA_INNODB_VERSION 35.0
+#define PERCONA_INNODB_VERSION 35.2
 #endif
 
-#define INNODB_VERSION_STR	"5.5.37-MariaDB-" IB_TO_STR(PERCONA_INNODB_VERSION)
+#define INNODB_VERSION_STR	"5.5.38-MariaDB-" IB_TO_STR(PERCONA_INNODB_VERSION)
 
 #define REFMAN "http://dev.mysql.com/doc/refman/"	\
 	IB_TO_STR(MYSQL_MAJOR_VERSION) "."		\
diff --git a/storage/xtradb/row/row0ins.c b/storage/xtradb/row/row0ins.c
index af2692b2f2e..6548e6abba9 100644
--- a/storage/xtradb/row/row0ins.c
+++ b/storage/xtradb/row/row0ins.c
@@ -143,6 +143,7 @@ row_ins_alloc_sys_fields(
 	const dict_col_t*	col;
 	dfield_t*		dfield;
 	byte*			ptr;
+	uint			len;
 
 	row = node->row;
 	table = node->table;
@@ -151,35 +152,37 @@ row_ins_alloc_sys_fields(
 	ut_ad(row && table && heap);
 	ut_ad(dtuple_get_n_fields(row) == dict_table_get_n_cols(table));
 
-	/* 1. Allocate buffer for row id */
+	/* allocate buffer to hold the needed system created hidden columns. */
+	len = DATA_ROW_ID_LEN + DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN;
+	ptr = mem_heap_zalloc(heap, len);
 
+	/* 1. Populate row-id */
 	col = dict_table_get_sys_col(table, DATA_ROW_ID);
 
 	dfield = dtuple_get_nth_field(row, dict_col_get_no(col));
 
-	ptr = mem_heap_zalloc(heap, DATA_ROW_ID_LEN);
-
 	dfield_set_data(dfield, ptr, DATA_ROW_ID_LEN);
 
 	node->row_id_buf = ptr;
 
-	/* 3. Allocate buffer for trx id */
+	ptr += DATA_ROW_ID_LEN;
 
+	/* 2. Populate trx id */
 	col = dict_table_get_sys_col(table, DATA_TRX_ID);
 
 	dfield = dtuple_get_nth_field(row, dict_col_get_no(col));
-	ptr = mem_heap_zalloc(heap, DATA_TRX_ID_LEN);
 
 	dfield_set_data(dfield, ptr, DATA_TRX_ID_LEN);
 
 	node->trx_id_buf = ptr;
 
-	/* 4. Allocate buffer for roll ptr */
+	ptr += DATA_TRX_ID_LEN;
+
+	/* 3. Populate roll ptr */
 
 	col = dict_table_get_sys_col(table, DATA_ROLL_PTR);
 
 	dfield = dtuple_get_nth_field(row, dict_col_get_no(col));
-	ptr = mem_heap_zalloc(heap, DATA_ROLL_PTR_LEN);
 
 	dfield_set_data(dfield, ptr, DATA_ROLL_PTR_LEN);
 }