Revert most of revno 3560.9.1 (Bug#12704861)

This was an attempt to address problems with the Bug#12612184 fix.
Even with this follow-up fix, crash recovery can be broken.
Let us fix the bug later.

27 files changed, 415 insertions, 972 deletions

diff --git a/storage/innobase/btr/btr0btr.c b/storage/innobase/btr/btr0btr.c
index ad99913cf3b..e8e065a3116 100644
--- a/storage/innobase/btr/btr0btr.c
+++ b/storage/innobase/btr/btr0btr.c
@@ -300,30 +300,29 @@ btr_page_alloc_for_ibuf(
 /******************************************************************
 Allocates a new file page to be used in an index tree. NOTE: we assume
 that the caller has made the reservation for free extents! */
-static
-ulint
-btr_page_alloc_low(
-/*===============*/
-					/* out: allocated page number,
-					FIL_NULL if out of space */
+
+page_t*
+btr_page_alloc(
+/*===========*/
+					/* out: new allocated page, x-latched;
+					NULL if out of space */
 	dict_index_t*	index,		/* in: index */
 	ulint		hint_page_no,	/* in: hint of a good page */
 	byte		file_direction,	/* in: direction where a possible
 					page split is made */
 	ulint		level,		/* in: level where the page is placed
 					in the tree */
-	mtr_t*		mtr,		/* in/out: mini-transaction
-					for the allocation */
-	mtr_t*		init_mtr)	/* in/out: mini-transaction
-					in which the page should be
-					initialized (may be the same
-					as mtr), or NULL if it should
-					not be initialized (the page
-					at hint was previously freed
-					in mtr) */
+	mtr_t*		mtr)		/* in: mtr */
 {
 	fseg_header_t*	seg_header;
 	page_t*		root;
+	page_t*		new_page;
+	ulint		new_page_no;
+
+	if (index->type & DICT_IBUF) {
+
+		return(btr_page_alloc_for_ibuf(index, mtr));
+	}
 
 	root = btr_root_get(index, mtr);
 
@@ -337,61 +336,19 @@ btr_page_alloc_low(
 	reservation for free extents, and thus we know that a page can
 	be allocated: */
 
-	return(fseg_alloc_free_page_general(seg_header, hint_page_no,
-					    file_direction, TRUE,
-					    mtr, init_mtr));
-}
-
-/**************************************************************//**
-Allocates a new file page to be used in an index tree. NOTE: we assume
-that the caller has made the reservation for free extents! */
-
-page_t*
-btr_page_alloc(
-/*===========*/
-					/* out:	new allocated block, x-latched;
-					NULL if out of space */
-	dict_index_t*	index,		/* in: index */
-	ulint		hint_page_no,	/* in: hint of a good page */
-	byte		file_direction,	/* in: direction where a possible
-					page split is made */
-	ulint		level,		/* in: level where the page is placed
-					in the tree */
-	mtr_t*		mtr,		/* in/out: mini-transaction
-					for the allocation */
-	mtr_t*		init_mtr)	/* in/out: mini-transaction
-					for x-latching and initializing
-					the page */
-{
-	page_t*		new_page;
-	ulint		new_page_no;
-
-	if (index->type & DICT_IBUF) {
-
-		return(btr_page_alloc_for_ibuf(index, mtr));
-	}
-
-	new_page_no = btr_page_alloc_low(
-		index, hint_page_no, file_direction, level, mtr, init_mtr);
-
+	new_page_no = fseg_alloc_free_page_general(seg_header, hint_page_no,
+						   file_direction, TRUE, mtr);
 	if (new_page_no == FIL_NULL) {
 
 		return(NULL);
 	}
 
 	new_page = buf_page_get(dict_index_get_space(index), new_page_no,
-				RW_X_LATCH, init_mtr);
+				RW_X_LATCH, mtr);
 #ifdef UNIV_SYNC_DEBUG
 	buf_page_dbg_add_level(new_page, SYNC_TREE_NODE_NEW);
 #endif /* UNIV_SYNC_DEBUG */
 
-	if (mtr->freed_clust_leaf) {
-		mtr_memo_release(mtr, new_page, MTR_MEMO_FREE_CLUST_LEAF);
-		ut_ad(!mtr_memo_contains(mtr, buf_block_align(new_page),
-					 MTR_MEMO_FREE_CLUST_LEAF));
-	}
-
-	ut_ad(btr_freed_leaves_validate(mtr));
 	return(new_page);
 }
 
@@ -538,138 +495,8 @@ btr_page_free(
 	level = btr_page_get_level(page, mtr);
 
 	btr_page_free_low(index, page, level, mtr);
-
-	/* The handling of MTR_MEMO_FREE_CLUST_LEAF assumes this. */
-	ut_ad(mtr_memo_contains(mtr, buf_block_align(page),
-				MTR_MEMO_PAGE_X_FIX));
-
-	if (level == 0 && (index->type & DICT_CLUSTERED)) {
-		/* We may have to call btr_mark_freed_leaves() to
-		temporarily mark the block nonfree for invoking
-		btr_store_big_rec_extern_fields() after an
-		update. Remember that the block was freed. */
-		mtr->freed_clust_leaf = TRUE;
-		mtr_memo_push(mtr, buf_block_align(page),
-			      MTR_MEMO_FREE_CLUST_LEAF);
-	}
-
-	ut_ad(btr_freed_leaves_validate(mtr));
 }
 
-/**************************************************************//**
-Marks all MTR_MEMO_FREE_CLUST_LEAF pages nonfree or free.
-For invoking btr_store_big_rec_extern_fields() after an update,
-we must temporarily mark freed clustered index pages allocated, so
-that off-page columns will not be allocated from them. Between the
-btr_store_big_rec_extern_fields() and mtr_commit() we have to
-mark the pages free again, so that no pages will be leaked. */
-
-void
-btr_mark_freed_leaves(
-/*==================*/
-	dict_index_t*	index,	/* in/out: clustered index */
-	mtr_t*		mtr,	/* in/out: mini-transaction */
-	ibool		nonfree)/* in: TRUE=mark nonfree, FALSE=mark freed */
-{
-	/* This is loosely based on mtr_memo_release(). */
-
-	ulint	offset;
-
-	ut_ad(index->type & DICT_CLUSTERED);
-	ut_ad(mtr->magic_n == MTR_MAGIC_N);
-	ut_ad(mtr->state == MTR_ACTIVE);
-
-	if (!mtr->freed_clust_leaf) {
-		return;
-	}
-
-	offset = dyn_array_get_data_size(&mtr->memo);
-
-	while (offset > 0) {
-		mtr_memo_slot_t*	slot;
-		buf_block_t*		block;
-
-		offset -= sizeof *slot;
-
-		slot = dyn_array_get_element(&mtr->memo, offset);
-
-		if (slot->type != MTR_MEMO_FREE_CLUST_LEAF) {
-			continue;
-		}
-
-		/* Because btr_page_alloc() does invoke
-		mtr_memo_release on MTR_MEMO_FREE_CLUST_LEAF, all
-		blocks tagged with MTR_MEMO_FREE_CLUST_LEAF in the
-		memo must still be clustered index leaf tree pages. */
-		block = slot->object;
-		ut_a(buf_block_get_space(block)
-		     == dict_index_get_space(index));
-		ut_a(fil_page_get_type(buf_block_get_frame(block))
-		     == FIL_PAGE_INDEX);
-		ut_a(btr_page_get_level(buf_block_get_frame(block), mtr) == 0);
-
-		if (nonfree) {
-			/* Allocate the same page again. */
-			ulint	page_no;
-			page_no = btr_page_alloc_low(
-				index, buf_block_get_page_no(block),
-				FSP_NO_DIR, 0, mtr, NULL);
-			ut_a(page_no == buf_block_get_page_no(block));
-		} else {
-			/* Assert that the page is allocated and free it. */
-			btr_page_free_low(index, buf_block_get_frame(block),
-					  0, mtr);
-		}
-	}
-
-	ut_ad(btr_freed_leaves_validate(mtr));
-}
-
-#ifdef UNIV_DEBUG
-/**************************************************************//**
-Validates all pages marked MTR_MEMO_FREE_CLUST_LEAF.
-See btr_mark_freed_leaves(). */
-
-ibool
-btr_freed_leaves_validate(
-/*======================*/
-			/* out: TRUE if valid */
-	mtr_t*	mtr)	/* in: mini-transaction */
-{
-	ulint	offset;
-
-	ut_ad(mtr->magic_n == MTR_MAGIC_N);
-	ut_ad(mtr->state == MTR_ACTIVE);
-
-	offset = dyn_array_get_data_size(&mtr->memo);
-
-	while (offset > 0) {
-		mtr_memo_slot_t*	slot;
-		buf_block_t*		block;
-
-		offset -= sizeof *slot;
-
-		slot = dyn_array_get_element(&mtr->memo, offset);
-
-		if (slot->type != MTR_MEMO_FREE_CLUST_LEAF) {
-			continue;
-		}
-
-		ut_a(mtr->freed_clust_leaf);
-		/* Because btr_page_alloc() does invoke
-		mtr_memo_release on MTR_MEMO_FREE_CLUST_LEAF, all
-		blocks tagged with MTR_MEMO_FREE_CLUST_LEAF in the
-		memo must still be clustered index leaf tree pages. */
-		block = slot->object;
-		ut_a(fil_page_get_type(buf_block_get_frame(block))
-		     == FIL_PAGE_INDEX);
-		ut_a(btr_page_get_level(buf_block_get_frame(block), mtr) == 0);
-	}
-
-	return(TRUE);
-}
-#endif /* UNIV_DEBUG */
-
 /******************************************************************
 Sets the child node file address in a node pointer. */
 UNIV_INLINE
@@ -1199,7 +1026,7 @@ btr_root_raise_and_insert(
 	a node pointer to the new page, and then splitting the new page. */
 
 	new_page = btr_page_alloc(index, 0, FSP_NO_DIR,
-				  btr_page_get_level(root, mtr), mtr, mtr);
+				  btr_page_get_level(root, mtr), mtr);
 
 	btr_page_create(new_page, index, mtr);
 
@@ -1820,7 +1647,7 @@ func_start:
 
 	/* 2. Allocate a new page to the index */
 	new_page = btr_page_alloc(cursor->index, hint_page_no, direction,
-				  btr_page_get_level(page, mtr), mtr, mtr);
+				  btr_page_get_level(page, mtr), mtr);
 	btr_page_create(new_page, cursor->index, mtr);
 
 	/* 3. Calculate the first record on the upper half-page, and the
diff --git a/storage/innobase/btr/btr0cur.c b/storage/innobase/btr/btr0cur.c
index 37bb3188785..95d87344e93 100644
--- a/storage/innobase/btr/btr0cur.c
+++ b/storage/innobase/btr/btr0cur.c
@@ -2051,6 +2051,43 @@ return_after_reservations:
 	return(err);
 }
 
+/*****************************************************************
+Commits and restarts a mini-transaction so that it will retain an
+x-lock on index->lock and the cursor page. */
+
+void
+btr_cur_mtr_commit_and_start(
+/*=========================*/
+	btr_cur_t*	cursor,	/* in: cursor */
+	mtr_t*		mtr)	/* in/out: mini-transaction */
+{
+	buf_block_t*	block;
+
+	block = buf_block_align(btr_cur_get_rec(cursor));
+
+	ut_ad(mtr_memo_contains(mtr, dict_index_get_lock(cursor->index),
+				MTR_MEMO_X_LOCK));
+	ut_ad(mtr_memo_contains(mtr, block, MTR_MEMO_PAGE_X_FIX));
+	/* Keep the locks across the mtr_commit(mtr). */
+	rw_lock_x_lock(dict_index_get_lock(cursor->index));
+	rw_lock_x_lock(&block->lock);
+	mutex_enter(&block->mutex);
+#ifdef UNIV_SYNC_DEBUG
+	buf_block_buf_fix_inc_debug(block, __FILE__, __LINE__);
+#else
+	buf_block_buf_fix_inc(block);
+#endif
+	mutex_exit(&block->mutex);
+	/* Write out the redo log. */
+	mtr_commit(mtr);
+	mtr_start(mtr);
+	/* Reassociate the locks with the mini-transaction.
+	They will be released on mtr_commit(mtr). */
+	mtr_memo_push(mtr, dict_index_get_lock(cursor->index),
+		      MTR_MEMO_X_LOCK);
+	mtr_memo_push(mtr, block, MTR_MEMO_PAGE_X_FIX);
+}
+
 /*==================== B-TREE DELETE MARK AND UNMARK ===============*/
 
 /********************************************************************
@@ -3449,11 +3486,6 @@ btr_store_big_rec_extern_fields(
 					this function returns */
 	big_rec_t*	big_rec_vec,	/* in: vector containing fields
 					to be stored externally */
-	mtr_t*		alloc_mtr,	/* in/out: in an insert, NULL;
-					in an update, local_mtr for
-					allocating BLOB pages and
-					updating BLOB pointers; alloc_mtr
-					must not have freed any leaf pages */
 	mtr_t*		local_mtr __attribute__((unused))) /* in: mtr
 					containing the latch to rec and to the
 					tree */
@@ -3474,8 +3506,6 @@ btr_store_big_rec_extern_fields(
 	ulint	i;
 	mtr_t	mtr;
 
-	ut_ad(local_mtr);
-	ut_ad(!alloc_mtr || alloc_mtr == local_mtr);
 	ut_ad(rec_offs_validate(rec, index, offsets));
 	ut_ad(mtr_memo_contains(local_mtr, dict_index_get_lock(index),
 				MTR_MEMO_X_LOCK));
@@ -3485,25 +3515,6 @@ btr_store_big_rec_extern_fields(
 
 	space_id = buf_frame_get_space_id(rec);
 
-	if (alloc_mtr) {
-		/* Because alloc_mtr will be committed after
-		mtr, it is possible that the tablespace has been
-		extended when the B-tree record was updated or
-		inserted, or it will be extended while allocating
-		pages for big_rec.
-
-		TODO: In mtr (not alloc_mtr), write a redo log record
-		about extending the tablespace to its current size,
-		and remember the current size. Whenever the tablespace
-		grows as pages are allocated, write further redo log
-		records to mtr. (Currently tablespace extension is not
-		covered by the redo log. If it were, the record would
-		only be written to alloc_mtr, which is committed after
-		mtr.) */
-	} else {
-		alloc_mtr = &mtr;
-	}
-
 	/* We have to create a file segment to the tablespace
 	for each field and put the pointer to the field in rec */
 
@@ -3530,7 +3541,7 @@ btr_store_big_rec_extern_fields(
 			}
 
 			page = btr_page_alloc(index, hint_page_no,
-					      FSP_NO_DIR, 0, alloc_mtr, &mtr);
+					      FSP_NO_DIR, 0, &mtr);
 			if (page == NULL) {
 
 				mtr_commit(&mtr);
@@ -3584,42 +3595,37 @@ btr_store_big_rec_extern_fields(
 
 			extern_len -= store_len;
 
-			if (alloc_mtr == &mtr) {
 #ifdef UNIV_SYNC_DEBUG
-				rec_page =
+			rec_page =
 #endif /* UNIV_SYNC_DEBUG */
-					buf_page_get(
-						space_id,
-						buf_frame_get_page_no(data),
-						RW_X_LATCH, &mtr);
+			buf_page_get(space_id,
+				     buf_frame_get_page_no(data),
+				     RW_X_LATCH, &mtr);
 #ifdef UNIV_SYNC_DEBUG
-				buf_page_dbg_add_level(
-					rec_page, SYNC_NO_ORDER_CHECK);
+			buf_page_dbg_add_level(rec_page, SYNC_NO_ORDER_CHECK);
 #endif /* UNIV_SYNC_DEBUG */
-			}
-
 			mlog_write_ulint(data + local_len + BTR_EXTERN_LEN, 0,
-					 MLOG_4BYTES, alloc_mtr);
+					 MLOG_4BYTES, &mtr);
 			mlog_write_ulint(data + local_len + BTR_EXTERN_LEN + 4,
 					 big_rec_vec->fields[i].len
 					 - extern_len,
-					 MLOG_4BYTES, alloc_mtr);
+					 MLOG_4BYTES, &mtr);
 
 			if (prev_page_no == FIL_NULL) {
 				mlog_write_ulint(data + local_len
 						 + BTR_EXTERN_SPACE_ID,
 						 space_id,
-						 MLOG_4BYTES, alloc_mtr);
+						 MLOG_4BYTES, &mtr);
 
 				mlog_write_ulint(data + local_len
 						 + BTR_EXTERN_PAGE_NO,
 						 page_no,
-						 MLOG_4BYTES, alloc_mtr);
+						 MLOG_4BYTES, &mtr);
 
 				mlog_write_ulint(data + local_len
 						 + BTR_EXTERN_OFFSET,
 						 FIL_PAGE_DATA,
-						 MLOG_4BYTES, alloc_mtr);
+						 MLOG_4BYTES, &mtr);
 
 				/* Set the bit denoting that this field
 				in rec is stored externally */
@@ -3627,7 +3633,7 @@ btr_store_big_rec_extern_fields(
 				rec_set_nth_field_extern_bit(
 					rec, index,
 					big_rec_vec->fields[i].field_no,
-					TRUE, alloc_mtr);
+					TRUE, &mtr);
 			}
 
 			prev_page_no = page_no;
diff --git a/storage/innobase/fsp/fsp0fsp.c b/storage/innobase/fsp/fsp0fsp.c
index d5be8fca38f..90e6ad34a9a 100644
--- a/storage/innobase/fsp/fsp0fsp.c
+++ b/storage/innobase/fsp/fsp0fsp.c
@@ -300,12 +300,8 @@ fseg_alloc_free_page_low(
 				inserted there in order, into which
 				direction they go alphabetically: FSP_DOWN,
 				FSP_UP, FSP_NO_DIR */
-	mtr_t*		mtr,	/* in/out: mini-transaction */
-	mtr_t*		init_mtr);/* in/out: mini-transaction in which the
-				page should be initialized
-				(may be the same as mtr), or NULL if it
-				should not be initialized (the page at hint
-				was previously freed in mtr) */
+	mtr_t*		mtr);	/* in/out: mini-transaction */
+
 
 /**************************************************************************
 Reads the file space size stored in the header page. */
@@ -1375,43 +1371,6 @@ fsp_alloc_free_extent(
 	return(descr);
 }
 
-/**********************************************************************//**
-Allocates a single free page from a space. */
-static __attribute__((nonnull))
-void
-fsp_alloc_from_free_frag(
-/*=====================*/
-	fsp_header_t*	header,	/* in/out: tablespace header */
-	xdes_t*		descr,	/* in/out: extent descriptor */
-	ulint		bit,	/* in: slot to allocate in the extent */
-	mtr_t*		mtr)	/* in/out: mini-transaction */
-{
-	ulint		frag_n_used;
-
-	ut_ad(xdes_get_state(descr, mtr) == XDES_FREE_FRAG);
-	ut_a(xdes_get_bit(descr, XDES_FREE_BIT, bit, mtr));
-	xdes_set_bit(descr, XDES_FREE_BIT, bit, FALSE, mtr);
-
-	/* Update the FRAG_N_USED field */
-	frag_n_used = mtr_read_ulint(header + FSP_FRAG_N_USED, MLOG_4BYTES,
-				     mtr);
-	frag_n_used++;
-	mlog_write_ulint(header + FSP_FRAG_N_USED, frag_n_used, MLOG_4BYTES,
-			 mtr);
-	if (xdes_is_full(descr, mtr)) {
-		/* The fragment is full: move it to another list */
-		flst_remove(header + FSP_FREE_FRAG, descr + XDES_FLST_NODE,
-			    mtr);
-		xdes_set_state(descr, XDES_FULL_FRAG, mtr);
-
-		flst_add_last(header + FSP_FULL_FRAG, descr + XDES_FLST_NODE,
-			      mtr);
-		mlog_write_ulint(header + FSP_FRAG_N_USED,
-				 frag_n_used - FSP_EXTENT_SIZE, MLOG_4BYTES,
-				 mtr);
-	}
-}
-
 /**************************************************************************
 Allocates a single free page from a space. The page is marked as used. */
 static
@@ -1422,22 +1381,19 @@ fsp_alloc_free_page(
 			be allocated */
 	ulint	space,	/* in: space id */
 	ulint	hint,	/* in: hint of which page would be desirable */
-	mtr_t*	mtr,	/* in/out: mini-transaction */
-	mtr_t*	init_mtr)/* in/out: mini-transaction in which the
-			page should be initialized
-			(may be the same as mtr) */
+	mtr_t*	mtr)	/* in/out: mini-transaction */
 {
 	fsp_header_t*	header;
 	fil_addr_t	first;
 	xdes_t*		descr;
 	page_t*		page;
 	ulint		free;
+	ulint		frag_n_used;
 	ulint		page_no;
 	ulint		space_size;
 	ibool		success;
 
 	ut_ad(mtr);
-	ut_ad(init_mtr);
 
 	header = fsp_get_space_header(space, mtr);
 
@@ -1517,21 +1473,40 @@ fsp_alloc_free_page(
 		}
 	}
 
-	fsp_alloc_from_free_frag(header, descr, free, mtr);
+	xdes_set_bit(descr, XDES_FREE_BIT, free, FALSE, mtr);
+
+	/* Update the FRAG_N_USED field */
+	frag_n_used = mtr_read_ulint(header + FSP_FRAG_N_USED, MLOG_4BYTES,
+				     mtr);
+	frag_n_used++;
+	mlog_write_ulint(header + FSP_FRAG_N_USED, frag_n_used, MLOG_4BYTES,
+			 mtr);
+	if (xdes_is_full(descr, mtr)) {
+		/* The fragment is full: move it to another list */
+		flst_remove(header + FSP_FREE_FRAG, descr + XDES_FLST_NODE,
+			    mtr);
+		xdes_set_state(descr, XDES_FULL_FRAG, mtr);
+
+		flst_add_last(header + FSP_FULL_FRAG, descr + XDES_FLST_NODE,
+			      mtr);
+		mlog_write_ulint(header + FSP_FRAG_N_USED,
+				 frag_n_used - FSP_EXTENT_SIZE, MLOG_4BYTES,
+				 mtr);
+	}
 
 	/* Initialize the allocated page to the buffer pool, so that it can
 	be obtained immediately with buf_page_get without need for a disk
 	read. */
 
-	buf_page_create(space, page_no, init_mtr);
+	buf_page_create(space, page_no, mtr);
 
-	page = buf_page_get(space, page_no, RW_X_LATCH, init_mtr);
+	page = buf_page_get(space, page_no, RW_X_LATCH, mtr);
 #ifdef UNIV_SYNC_DEBUG
 	buf_page_dbg_add_level(page, SYNC_FSP_PAGE);
 #endif /* UNIV_SYNC_DEBUG */
 
 	/* Prior contents of the page should be ignored */
-	fsp_init_file_page(page, init_mtr);
+	fsp_init_file_page(page, mtr);
 
 	return(page_no);
 }
@@ -1750,7 +1725,7 @@ fsp_alloc_seg_inode_page(
 
 	space = buf_frame_get_space_id(space_header);
 
-	page_no = fsp_alloc_free_page(space, 0, mtr, mtr);
+	page_no = fsp_alloc_free_page(space, 0, mtr);
 
 	if (page_no == FIL_NULL) {
 
@@ -2120,8 +2095,7 @@ fseg_create_general(
 	}
 
 	if (page == 0) {
-		page = fseg_alloc_free_page_low(space,
-						inode, 0, FSP_UP, mtr, mtr);
+		page = fseg_alloc_free_page_low(space, inode, 0, FSP_UP, mtr);
 
 		if (page == FIL_NULL) {
 
@@ -2365,12 +2339,7 @@ fseg_alloc_free_page_low(
 				inserted there in order, into which
 				direction they go alphabetically: FSP_DOWN,
 				FSP_UP, FSP_NO_DIR */
-	mtr_t*		mtr,	/* in/out: mini-transaction */
-	mtr_t*		init_mtr)/* in/out: mini-transaction in which the
-				page should be initialized
-				(may be the same as mtr), or NULL if it
-				should not be initialized (the page at hint
-				was previously freed in mtr) */
+	mtr_t*		mtr)	/* in/out: mini-transaction */
 {
 	fsp_header_t*	space_header;
 	ulint		space_size;
@@ -2382,6 +2351,7 @@ fseg_alloc_free_page_low(
 					if could not be allocated */
 	xdes_t*		ret_descr;	/* the extent of the allocated page */
 	page_t*		page;
+	ibool		frag_page_allocated = FALSE;
 	ibool		success;
 	ulint		n;
 
@@ -2402,8 +2372,6 @@ fseg_alloc_free_page_low(
 	if (descr == NULL) {
 		/* Hint outside space or too high above free limit: reset
 		hint */
-		ut_a(init_mtr);
-		/* The file space header page is always allocated. */
 		hint = 0;
 		descr = xdes_get_descriptor(space, hint, mtr);
 	}
@@ -2415,20 +2383,15 @@ fseg_alloc_free_page_low(
 						   mtr), seg_id))
 	    && (xdes_get_bit(descr, XDES_FREE_BIT,
 			     hint % FSP_EXTENT_SIZE, mtr) == TRUE)) {
-take_hinted_page:
+
 		/* 1. We can take the hinted page
 		=================================*/
 		ret_descr = descr;
 		ret_page = hint;
-		/* Skip the check for extending the tablespace. If the
-		page hint were not within the size of the tablespace,
-		we would have got (descr == NULL) above and reset the hint. */
-		goto got_hinted_page;
 		/*-----------------------------------------------------------*/
-	} else if (xdes_get_state(descr, mtr) == XDES_FREE
-		   && (!init_mtr
-		       || ((reserved - used < reserved / FSEG_FILLFACTOR)
-			   && used >= FSEG_FRAG_LIMIT))) {
+	} else if ((xdes_get_state(descr, mtr) == XDES_FREE)
+		   && ((reserved - used) < reserved / FSEG_FILLFACTOR)
+		   && (used >= FSEG_FRAG_LIMIT)) {
 
 		/* 2. We allocate the free extent from space and can take
 		=========================================================
@@ -2446,20 +2409,8 @@ take_hinted_page:
 		/* Try to fill the segment free list */
 		fseg_fill_free_list(seg_inode, space,
 				    hint + FSP_EXTENT_SIZE, mtr);
-		goto take_hinted_page;
-		/*-----------------------------------------------------------*/
-	} else if (!init_mtr) {
-		ut_a(xdes_get_state(descr, mtr) == XDES_FREE_FRAG);
-		fsp_alloc_from_free_frag(space_header, descr,
-					 hint % FSP_EXTENT_SIZE, mtr);
 		ret_page = hint;
-		ret_descr = NULL;
-
-		/* Put the page in the fragment page array of the segment */
-		n = fseg_find_free_frag_page_slot(seg_inode, mtr);
-		ut_a(n != FIL_NULL);
-		fseg_set_nth_frag_page_no(seg_inode, n, ret_page, mtr);
-		goto got_hinted_page;
+		/*-----------------------------------------------------------*/
 	} else if ((direction != FSP_NO_DIR)
 		   && ((reserved - used) < reserved / FSEG_FILLFACTOR)
 		   && (used >= FSEG_FRAG_LIMIT)
@@ -2517,9 +2468,11 @@ take_hinted_page:
 	} else if (used < FSEG_FRAG_LIMIT) {
 		/* 6. We allocate an individual page from the space
 		===================================================*/
-		ret_page = fsp_alloc_free_page(space, hint, mtr, init_mtr);
+		ret_page = fsp_alloc_free_page(space, hint, mtr);
 		ret_descr = NULL;
 
+		frag_page_allocated = TRUE;
+
 		if (ret_page != FIL_NULL) {
 			/* Put the page in the fragment page array of the
 			segment */
@@ -2529,10 +2482,6 @@ take_hinted_page:
 			fseg_set_nth_frag_page_no(seg_inode, n, ret_page,
 						  mtr);
 		}
-
-		/* fsp_alloc_free_page() invoked fsp_init_file_page()
-		already. */
-		return(ret_page);
 		/*-----------------------------------------------------------*/
 	} else {
 		/* 7. We allocate a new extent and take its first page
@@ -2579,31 +2528,22 @@ take_hinted_page:
 		}
 	}
 
-got_hinted_page:
-	{
+	if (!frag_page_allocated) {
 		/* Initialize the allocated page to buffer pool, so that it
 		can be obtained immediately with buf_page_get without need
 		for a disk read */
-		mtr_t*	block_mtr = init_mtr ? init_mtr : mtr;
 
-		page = buf_page_create(space, ret_page, block_mtr);
+		page = buf_page_create(space, ret_page, mtr);
 
-		ut_a(page == buf_page_get(space, ret_page, RW_X_LATCH,
-					  block_mtr));
+		ut_a(page == buf_page_get(space, ret_page, RW_X_LATCH, mtr));
 
 #ifdef UNIV_SYNC_DEBUG
 		buf_page_dbg_add_level(page, SYNC_FSP_PAGE);
 #endif /* UNIV_SYNC_DEBUG */
 
-		if (init_mtr) {
-			/* The prior contents of the page should be ignored */
-			fsp_init_file_page(page, init_mtr);
-		}
-	}
+		/* The prior contents of the page should be ignored */
+		fsp_init_file_page(page, mtr);
 
-	/* ret_descr == NULL if the block was allocated from free_frag
-	(XDES_FREE_FRAG) */
-	if (ret_descr != NULL) {
 		/* At this point we know the extent and the page offset.
 		The extent is still in the appropriate list (FSEG_NOT_FULL
 		or FSEG_FREE), and the page is not yet marked as used. */
@@ -2640,11 +2580,7 @@ fseg_alloc_free_page_general(
 				with fsp_reserve_free_extents, then there
 				is no need to do the check for this individual
 				page */
-	mtr_t*		mtr,	/* in/out: mini-transaction handle */
-	mtr_t*		init_mtr)/* in/out: mtr or another mini-transaction
-				in which the page should be initialized,
-				or NULL if this is a "fake allocation" of
-				a page that was previously freed in mtr */
+	mtr_t*		mtr)	/* in/out: mini-transaction */
 {
 	fseg_inode_t*	inode;
 	ulint		space;
@@ -2682,8 +2618,7 @@ fseg_alloc_free_page_general(
 	}
 
 	page_no = fseg_alloc_free_page_low(buf_frame_get_space_id(inode),
-					   inode, hint, direction,
-					   mtr, init_mtr);
+					   inode, hint, direction, mtr);
 	if (!has_done_reservation) {
 		fil_space_release_free_extents(space, n_reserved);
 	}
@@ -2711,7 +2646,7 @@ fseg_alloc_free_page(
 	mtr_t*		mtr)	/* in: mtr handle */
 {
 	return(fseg_alloc_free_page_general(seg_header, hint, direction,
-					    FALSE, mtr, mtr));
+					    FALSE, mtr));
 }
 
 /**************************************************************************
diff --git a/storage/innobase/include/btr0btr.h b/storage/innobase/include/btr0btr.h
index 3988019589d..269fa355558 100644
--- a/storage/innobase/include/btr0btr.h
+++ b/storage/innobase/include/btr0btr.h
@@ -379,11 +379,7 @@ btr_page_alloc(
 					page split is made */
 	ulint		level,		/* in: level where the page is placed
 					in the tree */
-	mtr_t*		mtr,		/* in/out: mini-transaction
-					for the allocation */
-	mtr_t*		init_mtr);	/* in/out: mini-transaction
-					for x-latching and initializing
-					the page */
+	mtr_t*		mtr);		/* in: mtr */
 /******************************************************************
 Frees a file page used in an index tree. NOTE: cannot free field external
 storage pages because the page must contain info on its level. */
@@ -406,31 +402,6 @@ btr_page_free_low(
 	page_t*		page,	/* in: page to be freed, x-latched */
 	ulint		level,	/* in: page level */
 	mtr_t*		mtr);	/* in: mtr */
-/**************************************************************//**
-Marks all MTR_MEMO_FREE_CLUST_LEAF pages nonfree or free.
-For invoking btr_store_big_rec_extern_fields() after an update,
-we must temporarily mark freed clustered index pages allocated, so
-that off-page columns will not be allocated from them. Between the
-btr_store_big_rec_extern_fields() and mtr_commit() we have to
-mark the pages free again, so that no pages will be leaked. */
-
-void
-btr_mark_freed_leaves(
-/*==================*/
-	dict_index_t*	index,	/* in/out: clustered index */
-	mtr_t*		mtr,	/* in/out: mini-transaction */
-	ibool		nonfree);/* in: TRUE=mark nonfree, FALSE=mark freed */
-#ifdef UNIV_DEBUG
-/**************************************************************//**
-Validates all pages marked MTR_MEMO_FREE_CLUST_LEAF.
-See btr_mark_freed_leaves(). */
-
-ibool
-btr_freed_leaves_validate(
-/*======================*/
-			/* out: TRUE if valid */
-	mtr_t*	mtr);	/* in: mini-transaction */
-#endif /* UNIV_DEBUG */
 #ifdef UNIV_BTR_PRINT
 /*****************************************************************
 Prints size info of a B-tree. */
diff --git a/storage/innobase/include/btr0cur.h b/storage/innobase/include/btr0cur.h
index c2bf84ef9cb..c068d8d3318 100644
--- a/storage/innobase/include/btr0cur.h
+++ b/storage/innobase/include/btr0cur.h
@@ -252,6 +252,15 @@ btr_cur_pessimistic_update(
 				updates */
 	que_thr_t*	thr,	/* in: query thread */
 	mtr_t*		mtr);	/* in: mtr */
+/*****************************************************************
+Commits and restarts a mini-transaction so that it will retain an
+x-lock on index->lock and the cursor page. */
+
+void
+btr_cur_mtr_commit_and_start(
+/*=========================*/
+	btr_cur_t*	cursor,	/* in: cursor */
+	mtr_t*		mtr);	/* in/out: mini-transaction */
 /***************************************************************
 Marks a clustered index record deleted. Writes an undo log record to
 undo log on this delete marking. Writes in the trx id field the id
@@ -462,11 +471,6 @@ btr_store_big_rec_extern_fields(
 					this function returns */
 	big_rec_t*	big_rec_vec,	/* in: vector containing fields
 					to be stored externally */
-	mtr_t*		alloc_mtr,	/* in/out: in an insert, NULL;
-					in an update, local_mtr for
-					allocating BLOB pages and
-					updating BLOB pointers; alloc_mtr
-					must not have freed any leaf pages */
 	mtr_t*		local_mtr);	/* in: mtr containing the latch to
 					rec and to the tree */
 /***********************************************************************
diff --git a/storage/innobase/include/fsp0fsp.h b/storage/innobase/include/fsp0fsp.h
index 4c58d6075e6..b7322944189 100644
--- a/storage/innobase/include/fsp0fsp.h
+++ b/storage/innobase/include/fsp0fsp.h
@@ -179,11 +179,7 @@ fseg_alloc_free_page_general(
 				with fsp_reserve_free_extents, then there
 				is no need to do the check for this individual
 				page */
-	mtr_t*		mtr,	/* in/out: mini-transaction */
-	mtr_t*		init_mtr);/* in/out: mtr or another mini-transaction
-				in which the page should be initialized,
-				or NULL if this is a "fake allocation" of
-				a page that was previously freed in mtr */
+	mtr_t*		mtr);	/* in/out: mini-transaction */
 /**************************************************************************
 Reserves free pages from a tablespace. All mini-transactions which may
 use several pages from the tablespace should call this function beforehand
diff --git a/storage/innobase/include/mtr0mtr.h b/storage/innobase/include/mtr0mtr.h
index 58983063361..2b41fa0059a 100644
--- a/storage/innobase/include/mtr0mtr.h
+++ b/storage/innobase/include/mtr0mtr.h
@@ -36,8 +36,6 @@ first 3 values must be RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */
 #define MTR_MEMO_MODIFY		54
 #define	MTR_MEMO_S_LOCK		55
 #define	MTR_MEMO_X_LOCK		56
-/* The mini-transaction freed a clustered index leaf page. */
-#define MTR_MEMO_FREE_CLUST_LEAF	57
 
 /* Log item types: we have made them to be of the type 'byte'
 for the compiler to warn if val and type parameters are switched
@@ -317,12 +315,9 @@ struct mtr_struct{
 	ulint		state;	/* MTR_ACTIVE, MTR_COMMITTING, MTR_COMMITTED */
 	dyn_array_t	memo;	/* memo stack for locks etc. */
 	dyn_array_t	log;	/* mini-transaction log */
-	unsigned	modifications:1;
+	ibool		modifications;
 				/* TRUE if the mtr made modifications to
 				buffer pool pages */
-	unsigned	freed_clust_leaf:1;
-				/* TRUE if MTR_MEMO_FREE_CLUST_LEAF
-				was logged in the mini-transaction */
 	ulint		n_log_recs;
 				/* count of how many page initial log records
 				have been written to the mtr log */
diff --git a/storage/innobase/include/mtr0mtr.ic b/storage/innobase/include/mtr0mtr.ic
index 6b4cacf0766..81eec3bfc92 100644
--- a/storage/innobase/include/mtr0mtr.ic
+++ b/storage/innobase/include/mtr0mtr.ic
@@ -26,7 +26,6 @@ mtr_start(
 
 	mtr->log_mode = MTR_LOG_ALL;
 	mtr->modifications = FALSE;
-	mtr->freed_clust_leaf = FALSE;
 	mtr->n_log_recs = 0;
 
 #ifdef UNIV_DEBUG
@@ -51,8 +50,7 @@ mtr_memo_push(
 
 	ut_ad(object);
 	ut_ad(type >= MTR_MEMO_PAGE_S_FIX);
-	ut_ad(type <= MTR_MEMO_FREE_CLUST_LEAF);
-	ut_ad(type != MTR_MEMO_FREE_CLUST_LEAF || mtr->freed_clust_leaf);
+	ut_ad(type <= MTR_MEMO_X_LOCK);
 	ut_ad(mtr);
 	ut_ad(mtr->magic_n == MTR_MAGIC_N);
 
diff --git a/storage/innobase/mtr/mtr0mtr.c b/storage/innobase/mtr/mtr0mtr.c
index 33b71f0766c..728c37ce564 100644
--- a/storage/innobase/mtr/mtr0mtr.c
+++ b/storage/innobase/mtr/mtr0mtr.c
@@ -53,13 +53,17 @@ mtr_memo_slot_release(
 			buf_page_release((buf_block_t*)object, type, mtr);
 		} else if (type == MTR_MEMO_S_LOCK) {
 			rw_lock_s_unlock((rw_lock_t*)object);
-		} else if (type != MTR_MEMO_X_LOCK) {
-			ut_ad(type == MTR_MEMO_MODIFY
-			      || type == MTR_MEMO_FREE_CLUST_LEAF);
+#ifdef UNIV_DEBUG
+		} else if (type == MTR_MEMO_X_LOCK) {
+			rw_lock_x_unlock((rw_lock_t*)object);
+		} else {
+			ut_ad(type == MTR_MEMO_MODIFY);
 			ut_ad(mtr_memo_contains(mtr, object,
 						MTR_MEMO_PAGE_X_FIX));
+#else
 		} else {
 			rw_lock_x_unlock((rw_lock_t*)object);
+#endif
 		}
 	}
 
diff --git a/storage/innobase/row/row0ins.c b/storage/innobase/row/row0ins.c
index f6e6c81534b..c3b8f54a3c5 100644
--- a/storage/innobase/row/row0ins.c
+++ b/storage/innobase/row/row0ins.c
@@ -2090,20 +2090,15 @@ row_ins_index_entry_low(
 			if (big_rec) {
 				ut_a(err == DB_SUCCESS);
 				/* Write out the externally stored
-				columns, but allocate the pages and
-				write the pointers using the
-				mini-transaction of the record update.
-				If any pages were freed in the update,
-				temporarily mark them allocated so
-				that off-page columns will not
-				overwrite them. We must do this,
-				because we will write the redo log for
-				the BLOB writes before writing the
-				redo log for the record update. Thus,
-				redo log application at crash recovery
-				will see BLOBs being written to free pages. */
-
-				btr_mark_freed_leaves(index, &mtr, TRUE);
+				columns while still x-latching
+				index->lock and block->lock. We have
+				to mtr_commit(mtr) first, so that the
+				redo log will be written in the
+				correct order. Otherwise, we would run
+				into trouble on crash recovery if mtr
+				freed B-tree pages on which some of
+				the big_rec fields will be written. */
+				btr_cur_mtr_commit_and_start(&cursor, &mtr);
 
 				rec = btr_cur_get_rec(&cursor);
 				offsets = rec_get_offsets(rec, index, offsets,
@@ -2111,8 +2106,7 @@ row_ins_index_entry_low(
 							  &heap);
 
 				err = btr_store_big_rec_extern_fields(
-					index, rec, offsets, big_rec,
-					&mtr, &mtr);
+					index, rec, offsets, big_rec, &mtr);
 				/* If writing big_rec fails (for
 				example, because of DB_OUT_OF_FILE_SPACE),
 				the record will be corrupted. Even if
@@ -2125,9 +2119,6 @@ row_ins_index_entry_low(
 				undo log, and thus the record cannot
 				be rolled back. */
 				ut_a(err == DB_SUCCESS);
-				/* Free the pages again
-				in order to avoid a leak. */
-				btr_mark_freed_leaves(index, &mtr, FALSE);
 				goto stored_big_rec;
 			}
 		} else {
@@ -2175,8 +2166,7 @@ function_exit:
 					  ULINT_UNDEFINED, &heap);
 
 		err = btr_store_big_rec_extern_fields(index, rec,
-						      offsets, big_rec,
-						      NULL, &mtr);
+						      offsets, big_rec, &mtr);
 stored_big_rec:
 		if (modify) {
 			dtuple_big_rec_free(big_rec);
diff --git a/storage/innobase/row/row0row.c b/storage/innobase/row/row0row.c
index ccb3c1f7781..171039e34ac 100644
--- a/storage/innobase/row/row0row.c
+++ b/storage/innobase/row/row0row.c
@@ -212,27 +212,23 @@ row_build(
 	}
 
 #if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
-	if (rec_offs_any_null_extern(rec, offsets)) {
-		/* This condition can occur during crash recovery
-		before trx_rollback_or_clean_all_without_sess() has
-		completed execution.
-
-		This condition is possible if the server crashed
-		during an insert or update before
-		btr_store_big_rec_extern_fields() did mtr_commit() all
-		BLOB pointers to the clustered index record.
-
-		If the record contains a null BLOB pointer, look up the
-		transaction that holds the implicit lock on this record, and
-		assert that it is active. (In this version of InnoDB, we
-		cannot assert that it was recovered, because there is no
-		trx->is_recovered field.) */
-
-		ut_a(trx_assert_active(
-			     row_get_rec_trx_id(rec, index, offsets)));
-		ut_a(trx_undo_roll_ptr_is_insert(
-			     row_get_rec_roll_ptr(rec, index, offsets)));
-	}
+	/* This condition can occur during crash recovery before
+	trx_rollback_or_clean_all_without_sess() has completed
+	execution.
+
+	This condition is possible if the server crashed
+	during an insert or update before
+	btr_store_big_rec_extern_fields() did mtr_commit() all
+	BLOB pointers to the clustered index record.
+
+	If the record contains a null BLOB pointer, look up the
+	transaction that holds the implicit lock on this record, and
+	assert that it is active. (In this version of InnoDB, we
+	cannot assert that it was recovered, because there is no
+	trx->is_recovered field.) */
+
+	ut_a(!rec_offs_any_null_extern(rec, offsets)
+	     || trx_assert_active(row_get_rec_trx_id(rec, index, offsets)));
 #endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 
 	if (type != ROW_COPY_POINTERS) {
diff --git a/storage/innobase/row/row0upd.c b/storage/innobase/row/row0upd.c
index 58739edfd98..694b00ea265 100644
--- a/storage/innobase/row/row0upd.c
+++ b/storage/innobase/row/row0upd.c
@@ -1591,22 +1591,21 @@ row_upd_clust_rec(
 		*offsets_ = (sizeof offsets_) / sizeof *offsets_;
 
 		ut_a(err == DB_SUCCESS);
-		/* Write out the externally stored columns, but
-		allocate the pages and write the pointers using the
-		mini-transaction of the record update. If any pages
-		were freed in the update, temporarily mark them
-		allocated so that off-page columns will not overwrite
-		them. We must do this, because we write the redo log
-		for the BLOB writes before writing the redo log for
-		the record update. */
-
-		btr_mark_freed_leaves(index, mtr, TRUE);
+		/* Write out the externally stored columns while still
+		x-latching index->lock and block->lock. We have to
+		mtr_commit(mtr) first, so that the redo log will be
+		written in the correct order. Otherwise, we would run
+		into trouble on crash recovery if mtr freed B-tree
+		pages on which some of the big_rec fields will be
+		written. */
+		btr_cur_mtr_commit_and_start(btr_cur, mtr);
+
 		rec = btr_cur_get_rec(btr_cur);
 		err = btr_store_big_rec_extern_fields(
 			index, rec,
 			rec_get_offsets(rec, index, offsets_,
 					ULINT_UNDEFINED, &heap),
-			big_rec, mtr, mtr);
+			big_rec, mtr);
 		if (UNIV_LIKELY_NULL(heap)) {
 			mem_heap_free(heap);
 		}
@@ -1619,8 +1618,6 @@ row_upd_clust_rec(
 		to the undo log, and thus the record cannot be rolled
 		back. */
 		ut_a(err == DB_SUCCESS);
-		/* Free the pages again in order to avoid a leak. */
-		btr_mark_freed_leaves(index, mtr, FALSE);
 	}
 
 	mtr_commit(mtr);
diff --git a/storage/innobase/trx/trx0undo.c b/storage/innobase/trx/trx0undo.c
index ce09862f317..329565943c8 100644
--- a/storage/innobase/trx/trx0undo.c
+++ b/storage/innobase/trx/trx0undo.c
@@ -864,7 +864,7 @@ trx_undo_add_page(
 	page_no = fseg_alloc_free_page_general(header_page + TRX_UNDO_SEG_HDR
 					       + TRX_UNDO_FSEG_HEADER,
 					       undo->top_page_no + 1, FSP_UP,
-					       TRUE, mtr, mtr);
+					       TRUE, mtr);
 
 	fil_space_release_free_extents(undo->space, n_reserved);
 
diff --git a/storage/innodb_plugin/ChangeLog b/storage/innodb_plugin/ChangeLog
index 4e6e2be615a..e6724eb08c2 100644
--- a/storage/innodb_plugin/ChangeLog
+++ b/storage/innodb_plugin/ChangeLog
@@ -50,15 +50,6 @@
 	* include/trx0undo.h, trx/trx0rec.c, trx/trx0undo.c:
 	Fix Bug#12547647 UPDATE LOGGING COULD EXCEED LOG PAGE SIZE
 
-2011-08-29	The InnoDB Team
-
-	* btr/btr0btr.c, btr/btr0cur.c, fsp/fsp0fsp.c,
-	include/btr0btr.h, include/btr0cur.h, include/fsp0fsp.h,
-	include/mtr0mtr.h, include/mtr0mtr.ic, mtr/mtr0mtr.c,
-	row/row0ins.c, row/row0row.c, row/row0upd.c, trx/trx0undo.c:
-	Fix Bug#12704861 Corruption after a crash during BLOB update
-	and other regressions from the fix of Bug#12612184
-
 2011-08-15	The InnoDB Team
 
 	* btr/btr0btr.c, btr/btr0cur.c, btr/btr0pcur.c, btr/btr0sea.c,
diff --git a/storage/innodb_plugin/btr/btr0btr.c b/storage/innodb_plugin/btr/btr0btr.c
index 71e1599d19e..cb94ef08cd6 100644
--- a/storage/innodb_plugin/btr/btr0btr.c
+++ b/storage/innodb_plugin/btr/btr0btr.c
@@ -906,29 +906,28 @@ btr_page_alloc_for_ibuf(
 /**************************************************************//**
 Allocates a new file page to be used in an index tree. NOTE: we assume
 that the caller has made the reservation for free extents!
-@return	allocated page number, FIL_NULL if out of space */
-static __attribute__((nonnull(1,5), warn_unused_result))
-ulint
-btr_page_alloc_low(
-/*===============*/
+@return	new allocated block, x-latched; NULL if out of space */
+UNIV_INTERN
+buf_block_t*
+btr_page_alloc(
+/*===========*/
 	dict_index_t*	index,		/*!< in: index */
 	ulint		hint_page_no,	/*!< in: hint of a good page */
 	byte		file_direction,	/*!< in: direction where a possible
 					page split is made */
 	ulint		level,		/*!< in: level where the page is placed
 					in the tree */
-	mtr_t*		mtr,		/*!< in/out: mini-transaction
-					for the allocation */
-	mtr_t*		init_mtr)	/*!< in/out: mini-transaction
-					in which the page should be
-					initialized (may be the same
-					as mtr), or NULL if it should
-					not be initialized (the page
-					at hint was previously freed
-					in mtr) */
+	mtr_t*		mtr)		/*!< in: mtr */
 {
 	fseg_header_t*	seg_header;
 	page_t*		root;
+	buf_block_t*	new_block;
+	ulint		new_page_no;
+
+	if (dict_index_is_ibuf(index)) {
+
+		return(btr_page_alloc_for_ibuf(index, mtr));
+	}
 
 	root = btr_root_get(index, mtr);
 
@@ -942,42 +941,8 @@ btr_page_alloc_low(
 	reservation for free extents, and thus we know that a page can
 	be allocated: */
 
-	return(fseg_alloc_free_page_general(
-		       seg_header, hint_page_no, file_direction,
-		       TRUE, mtr, init_mtr));
-}
-
-/**************************************************************//**
-Allocates a new file page to be used in an index tree. NOTE: we assume
-that the caller has made the reservation for free extents!
-@return	new allocated block, x-latched; NULL if out of space */
-UNIV_INTERN
-buf_block_t*
-btr_page_alloc(
-/*===========*/
-	dict_index_t*	index,		/*!< in: index */
-	ulint		hint_page_no,	/*!< in: hint of a good page */
-	byte		file_direction,	/*!< in: direction where a possible
-					page split is made */
-	ulint		level,		/*!< in: level where the page is placed
-					in the tree */
-	mtr_t*		mtr,		/*!< in/out: mini-transaction
-					for the allocation */
-	mtr_t*		init_mtr)	/*!< in/out: mini-transaction
-					for x-latching and initializing
-					the page */
-{
-	buf_block_t*	new_block;
-	ulint		new_page_no;
-
-	if (dict_index_is_ibuf(index)) {
-
-		return(btr_page_alloc_for_ibuf(index, mtr));
-	}
-
-	new_page_no = btr_page_alloc_low(
-		index, hint_page_no, file_direction, level, mtr, init_mtr);
-
+	new_page_no = fseg_alloc_free_page_general(seg_header, hint_page_no,
+						   file_direction, TRUE, mtr);
 	if (new_page_no == FIL_NULL) {
 
 		return(NULL);
@@ -985,16 +950,9 @@ btr_page_alloc(
 
 	new_block = buf_page_get(dict_index_get_space(index),
 				 dict_table_zip_size(index->table),
-				 new_page_no, RW_X_LATCH, init_mtr);
+				 new_page_no, RW_X_LATCH, mtr);
 	buf_block_dbg_add_level(new_block, SYNC_TREE_NODE_NEW);
 
-	if (mtr->freed_clust_leaf) {
-		mtr_memo_release(mtr, new_block, MTR_MEMO_FREE_CLUST_LEAF);
-		ut_ad(!mtr_memo_contains(mtr, new_block,
-					 MTR_MEMO_FREE_CLUST_LEAF));
-	}
-
-	ut_ad(btr_freed_leaves_validate(mtr));
 	return(new_block);
 }
 
@@ -1129,139 +1087,12 @@ btr_page_free(
 	buf_block_t*	block,	/*!< in: block to be freed, x-latched */
 	mtr_t*		mtr)	/*!< in: mtr */
 {
-	const page_t*	page	= buf_block_get_frame(block);
-	ulint		level	= btr_page_get_level(page, mtr);
-
-	ut_ad(fil_page_get_type(block->frame) == FIL_PAGE_INDEX);
-	btr_page_free_low(index, block, level, mtr);
-
-	/* The handling of MTR_MEMO_FREE_CLUST_LEAF assumes this. */
-	ut_ad(mtr_memo_contains(mtr, block, MTR_MEMO_PAGE_X_FIX));
-
-	if (level == 0 && dict_index_is_clust(index)) {
-		/* We may have to call btr_mark_freed_leaves() to
-		temporarily mark the block nonfree for invoking
-		btr_store_big_rec_extern_fields_func() after an
-		update. Remember that the block was freed. */
-		mtr->freed_clust_leaf = TRUE;
-		mtr_memo_push(mtr, block, MTR_MEMO_FREE_CLUST_LEAF);
-	}
-
-	ut_ad(btr_freed_leaves_validate(mtr));
-}
-
-/**************************************************************//**
-Marks all MTR_MEMO_FREE_CLUST_LEAF pages nonfree or free.
-For invoking btr_store_big_rec_extern_fields() after an update,
-we must temporarily mark freed clustered index pages allocated, so
-that off-page columns will not be allocated from them. Between the
-btr_store_big_rec_extern_fields() and mtr_commit() we have to
-mark the pages free again, so that no pages will be leaked. */
-UNIV_INTERN
-void
-btr_mark_freed_leaves(
-/*==================*/
-	dict_index_t*	index,	/*!< in/out: clustered index */
-	mtr_t*		mtr,	/*!< in/out: mini-transaction */
-	ibool		nonfree)/*!< in: TRUE=mark nonfree, FALSE=mark freed */
-{
-	/* This is loosely based on mtr_memo_release(). */
-
-	ulint	offset;
-
-	ut_ad(dict_index_is_clust(index));
-	ut_ad(mtr->magic_n == MTR_MAGIC_N);
-	ut_ad(mtr->state == MTR_ACTIVE);
-
-	if (!mtr->freed_clust_leaf) {
-		return;
-	}
-
-	offset = dyn_array_get_data_size(&mtr->memo);
-
-	while (offset > 0) {
-		mtr_memo_slot_t*	slot;
-		buf_block_t*		block;
-
-		offset -= sizeof *slot;
-
-		slot = dyn_array_get_element(&mtr->memo, offset);
-
-		if (slot->type != MTR_MEMO_FREE_CLUST_LEAF) {
-			continue;
-		}
-
-		/* Because btr_page_alloc() does invoke
-		mtr_memo_release on MTR_MEMO_FREE_CLUST_LEAF, all
-		blocks tagged with MTR_MEMO_FREE_CLUST_LEAF in the
-		memo must still be clustered index leaf tree pages. */
-		block = slot->object;
-		ut_a(buf_block_get_space(block)
-		     == dict_index_get_space(index));
-		ut_a(fil_page_get_type(buf_block_get_frame(block))
-		     == FIL_PAGE_INDEX);
-		ut_a(page_is_leaf(buf_block_get_frame(block)));
-
-		if (nonfree) {
-			/* Allocate the same page again. */
-			ulint	page_no;
-			page_no = btr_page_alloc_low(
-				index, buf_block_get_page_no(block),
-				FSP_NO_DIR, 0, mtr, NULL);
-			ut_a(page_no == buf_block_get_page_no(block));
-		} else {
-			/* Assert that the page is allocated and free it. */
-			btr_page_free_low(index, block, 0, mtr);
-		}
-	}
-
-	ut_ad(btr_freed_leaves_validate(mtr));
-}
-
-#ifdef UNIV_DEBUG
-/**************************************************************//**
-Validates all pages marked MTR_MEMO_FREE_CLUST_LEAF.
-@see btr_mark_freed_leaves()
-@return TRUE */
-UNIV_INTERN
-ibool
-btr_freed_leaves_validate(
-/*======================*/
-	mtr_t*	mtr)	/*!< in: mini-transaction */
-{
-	ulint	offset;
-
-	ut_ad(mtr->magic_n == MTR_MAGIC_N);
-	ut_ad(mtr->state == MTR_ACTIVE);
-
-	offset = dyn_array_get_data_size(&mtr->memo);
-
-	while (offset > 0) {
-		const mtr_memo_slot_t*	slot;
-		const buf_block_t*	block;
-
-		offset -= sizeof *slot;
-
-		slot = dyn_array_get_element(&mtr->memo, offset);
-
-		if (slot->type != MTR_MEMO_FREE_CLUST_LEAF) {
-			continue;
-		}
+	ulint		level;
 
-		ut_a(mtr->freed_clust_leaf);
-		/* Because btr_page_alloc() does invoke
-		mtr_memo_release on MTR_MEMO_FREE_CLUST_LEAF, all
-		blocks tagged with MTR_MEMO_FREE_CLUST_LEAF in the
-		memo must still be clustered index leaf tree pages. */
-		block = slot->object;
-		ut_a(fil_page_get_type(buf_block_get_frame(block))
-		     == FIL_PAGE_INDEX);
-		ut_a(page_is_leaf(buf_block_get_frame(block)));
-	}
+	level = btr_page_get_level(buf_block_get_frame(block), mtr);
 
-	return(TRUE);
+	btr_page_free_low(index, block, level, mtr);
 }
-#endif /* UNIV_DEBUG */
 
 /**************************************************************//**
 Sets the child node file address in a node pointer. */
@@ -1984,7 +1815,7 @@ btr_root_raise_and_insert(
 
 	level = btr_page_get_level(root, mtr);
 
-	new_block = btr_page_alloc(index, 0, FSP_NO_DIR, level, mtr, mtr);
+	new_block = btr_page_alloc(index, 0, FSP_NO_DIR, level, mtr);
 	new_page = buf_block_get_frame(new_block);
 	new_page_zip = buf_block_get_page_zip(new_block);
 	ut_a(!new_page_zip == !root_page_zip);
@@ -2720,7 +2551,7 @@ func_start:
 
 	/* 2. Allocate a new page to the index */
 	new_block = btr_page_alloc(cursor->index, hint_page_no, direction,
-				   btr_page_get_level(page, mtr), mtr, mtr);
+				   btr_page_get_level(page, mtr), mtr);
 	new_page = buf_block_get_frame(new_block);
 	new_page_zip = buf_block_get_page_zip(new_block);
 	btr_page_create(new_block, new_page_zip, cursor->index,
diff --git a/storage/innodb_plugin/btr/btr0cur.c b/storage/innodb_plugin/btr/btr0cur.c
index 1e603a6fc81..4c862f061c5 100644
--- a/storage/innodb_plugin/btr/btr0cur.c
+++ b/storage/innodb_plugin/btr/btr0cur.c
@@ -2421,6 +2421,39 @@ return_after_reservations:
 	return(err);
 }
 
+/**************************************************************//**
+Commits and restarts a mini-transaction so that it will retain an
+x-lock on index->lock and the cursor page. */
+UNIV_INTERN
+void
+btr_cur_mtr_commit_and_start(
+/*=========================*/
+	btr_cur_t*	cursor,	/*!< in: cursor */
+	mtr_t*		mtr)	/*!< in/out: mini-transaction */
+{
+	buf_block_t*	block;
+
+	block = btr_cur_get_block(cursor);
+
+	ut_ad(mtr_memo_contains(mtr, dict_index_get_lock(cursor->index),
+				MTR_MEMO_X_LOCK));
+	ut_ad(mtr_memo_contains(mtr, block, MTR_MEMO_PAGE_X_FIX));
+	/* Keep the locks across the mtr_commit(mtr). */
+	rw_lock_x_lock(dict_index_get_lock(cursor->index));
+	rw_lock_x_lock(&block->lock);
+	mutex_enter(&block->mutex);
+	buf_block_buf_fix_inc(block, __FILE__, __LINE__);
+	mutex_exit(&block->mutex);
+	/* Write out the redo log. */
+	mtr_commit(mtr);
+	mtr_start(mtr);
+	/* Reassociate the locks with the mini-transaction.
+	They will be released on mtr_commit(mtr). */
+	mtr_memo_push(mtr, dict_index_get_lock(cursor->index),
+		      MTR_MEMO_X_LOCK);
+	mtr_memo_push(mtr, block, MTR_MEMO_PAGE_X_FIX);
+}
+
 /*==================== B-TREE DELETE MARK AND UNMARK ===============*/
 
 /****************************************************************//**
@@ -3863,9 +3896,6 @@ btr_store_big_rec_extern_fields_func(
 					the "external storage" flags in offsets
 					will not correspond to rec when
 					this function returns */
-	const big_rec_t*big_rec_vec,	/*!< in: vector containing fields
-					to be stored externally */
-
 #ifdef UNIV_DEBUG
 	mtr_t*		local_mtr,	/*!< in: mtr containing the
 					latch to rec and to the tree */
@@ -3874,11 +3904,9 @@ btr_store_big_rec_extern_fields_func(
 	ibool		update_in_place,/*! in: TRUE if the record is updated
 					in place (not delete+insert) */
 #endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
-	mtr_t*		alloc_mtr)	/*!< in/out: in an insert, NULL;
-					in an update, local_mtr for
-					allocating BLOB pages and
-					updating BLOB pointers; alloc_mtr
-					must not have freed any leaf pages */
+	const big_rec_t*big_rec_vec)	/*!< in: vector containing fields
+					to be stored externally */
+
 {
 	ulint	rec_page_no;
 	byte*	field_ref;
@@ -3897,9 +3925,6 @@ btr_store_big_rec_extern_fields_func(
 
 	ut_ad(rec_offs_validate(rec, index, offsets));
 	ut_ad(rec_offs_any_extern(offsets));
-	ut_ad(local_mtr);
-	ut_ad(!alloc_mtr || alloc_mtr == local_mtr);
-	ut_ad(!update_in_place || alloc_mtr);
 	ut_ad(mtr_memo_contains(local_mtr, dict_index_get_lock(index),
 				MTR_MEMO_X_LOCK));
 	ut_ad(mtr_memo_contains(local_mtr, rec_block, MTR_MEMO_PAGE_X_FIX));
@@ -3915,25 +3940,6 @@ btr_store_big_rec_extern_fields_func(
 	rec_page_no = buf_block_get_page_no(rec_block);
 	ut_a(fil_page_get_type(page_align(rec)) == FIL_PAGE_INDEX);
 
-	if (alloc_mtr) {
-		/* Because alloc_mtr will be committed after
-		mtr, it is possible that the tablespace has been
-		extended when the B-tree record was updated or
-		inserted, or it will be extended while allocating
-		pages for big_rec.
-
-		TODO: In mtr (not alloc_mtr), write a redo log record
-		about extending the tablespace to its current size,
-		and remember the current size. Whenever the tablespace
-		grows as pages are allocated, write further redo log
-		records to mtr. (Currently tablespace extension is not
-		covered by the redo log. If it were, the record would
-		only be written to alloc_mtr, which is committed after
-		mtr.) */
-	} else {
-		alloc_mtr = &mtr;
-	}
-
 	if (UNIV_LIKELY_NULL(page_zip)) {
 		int	err;
 
@@ -4010,7 +4016,7 @@ btr_store_big_rec_extern_fields_func(
 			}
 
 			block = btr_page_alloc(index, hint_page_no,
-					       FSP_NO_DIR, 0, alloc_mtr, &mtr);
+					       FSP_NO_DIR, 0, &mtr);
 			if (UNIV_UNLIKELY(block == NULL)) {
 
 				mtr_commit(&mtr);
@@ -4137,15 +4143,11 @@ btr_store_big_rec_extern_fields_func(
 					goto next_zip_page;
 				}
 
-				if (alloc_mtr == &mtr) {
-					rec_block = buf_page_get(
-						space_id, zip_size,
-						rec_page_no,
-						RW_X_LATCH, &mtr);
-					buf_block_dbg_add_level(
-						rec_block,
-						SYNC_NO_ORDER_CHECK);
-				}
+				rec_block = buf_page_get(space_id, zip_size,
+							 rec_page_no,
+							 RW_X_LATCH, &mtr);
+				buf_block_dbg_add_level(rec_block,
+							SYNC_NO_ORDER_CHECK);
 
 				if (err == Z_STREAM_END) {
 					mach_write_to_4(field_ref
@@ -4179,8 +4181,7 @@ btr_store_big_rec_extern_fields_func(
 
 				page_zip_write_blob_ptr(
 					page_zip, rec, index, offsets,
-					big_rec_vec->fields[i].field_no,
-					alloc_mtr);
+					big_rec_vec->fields[i].field_no, &mtr);
 
 next_zip_page:
 				prev_page_no = page_no;
@@ -4225,23 +4226,19 @@ next_zip_page:
 
 				extern_len -= store_len;
 
-				if (alloc_mtr == &mtr) {
-					rec_block = buf_page_get(
-						space_id, zip_size,
-						rec_page_no,
-						RW_X_LATCH, &mtr);
-					buf_block_dbg_add_level(
-						rec_block,
-						SYNC_NO_ORDER_CHECK);
-				}
+				rec_block = buf_page_get(space_id, zip_size,
+							 rec_page_no,
+							 RW_X_LATCH, &mtr);
+				buf_block_dbg_add_level(rec_block,
+							SYNC_NO_ORDER_CHECK);
 
 				mlog_write_ulint(field_ref + BTR_EXTERN_LEN, 0,
-						 MLOG_4BYTES, alloc_mtr);
+						 MLOG_4BYTES, &mtr);
 				mlog_write_ulint(field_ref
 						 + BTR_EXTERN_LEN + 4,
 						 big_rec_vec->fields[i].len
 						 - extern_len,
-						 MLOG_4BYTES, alloc_mtr);
+						 MLOG_4BYTES, &mtr);
 
 				if (prev_page_no == FIL_NULL) {
 					btr_blob_dbg_add_blob(
@@ -4251,19 +4248,18 @@ next_zip_page:
 
 					mlog_write_ulint(field_ref
 							 + BTR_EXTERN_SPACE_ID,
-							 space_id, MLOG_4BYTES,
-							 alloc_mtr);
+							 space_id,
+							 MLOG_4BYTES, &mtr);
 
 					mlog_write_ulint(field_ref
 							 + BTR_EXTERN_PAGE_NO,
-							 page_no, MLOG_4BYTES,
-							 alloc_mtr);
+							 page_no,
+							 MLOG_4BYTES, &mtr);
 
 					mlog_write_ulint(field_ref
 							 + BTR_EXTERN_OFFSET,
 							 FIL_PAGE_DATA,
-							 MLOG_4BYTES,
-							 alloc_mtr);
+							 MLOG_4BYTES, &mtr);
 				}
 
 				prev_page_no = page_no;
diff --git a/storage/innodb_plugin/fsp/fsp0fsp.c b/storage/innodb_plugin/fsp/fsp0fsp.c
index 19846b63d5b..fee7fde2e5c 100644
--- a/storage/innodb_plugin/fsp/fsp0fsp.c
+++ b/storage/innodb_plugin/fsp/fsp0fsp.c
@@ -312,9 +312,8 @@ fsp_fill_free_list(
 					descriptor page and ibuf bitmap page;
 					then we do not allocate more extents */
 	ulint		space,		/*!< in: space */
-	fsp_header_t*	header,		/*!< in/out: space header */
-	mtr_t*		mtr)		/*!< in/out: mini-transaction */
-	__attribute__((nonnull));
+	fsp_header_t*	header,		/*!< in: space header */
+	mtr_t*		mtr);		/*!< in: mtr */
 /**********************************************************************//**
 Allocates a single free page from a segment. This function implements
 the intelligent allocation strategy which tries to minimize file space
@@ -334,13 +333,7 @@ fseg_alloc_free_page_low(
 				inserted there in order, into which
 				direction they go alphabetically: FSP_DOWN,
 				FSP_UP, FSP_NO_DIR */
-	mtr_t*		mtr,	/*!< in/out: mini-transaction */
-	mtr_t*		init_mtr)/*!< in/out: mini-transaction in which the
-				page should be initialized
-				(may be the same as mtr), or NULL if it
-				should not be initialized (the page at hint
-				was previously freed in mtr) */
-	__attribute__((warn_unused_result, nonnull(3,6)));
+	mtr_t*		mtr);	/*!< in/out: mini-transaction */
 #endif /* !UNIV_HOTBACKUP */
 
 /**********************************************************************//**
@@ -708,18 +701,17 @@ list, if not free limit == space size. This adding is necessary to make the
 descriptor defined, as they are uninitialized above the free limit.
 @return pointer to the extent descriptor, NULL if the page does not
 exist in the space or if the offset exceeds the free limit */
-UNIV_INLINE __attribute__((nonnull, warn_unused_result))
+UNIV_INLINE
 xdes_t*
 xdes_get_descriptor_with_space_hdr(
 /*===============================*/
-	fsp_header_t*	sp_header,	/*!< in/out: space header, x-latched
-					in mtr */
-	ulint		space,		/*!< in: space id */
-	ulint		offset,		/*!< in: page offset; if equal
-					to the free limit, we try to
-					add new extents to the space
-					free list */
-	mtr_t*		mtr)		/*!< in/out: mini-transaction */
+	fsp_header_t*	sp_header,/*!< in/out: space header, x-latched */
+	ulint		space,	/*!< in: space id */
+	ulint		offset,	/*!< in: page offset;
+				if equal to the free limit,
+				we try to add new extents to
+				the space free list */
+	mtr_t*		mtr)	/*!< in: mtr handle */
 {
 	ulint	limit;
 	ulint	size;
@@ -727,9 +719,11 @@ xdes_get_descriptor_with_space_hdr(
 	ulint	descr_page_no;
 	page_t*	descr_page;
 
+	ut_ad(mtr);
 	ut_ad(mtr_memo_contains(mtr, fil_space_get_latch(space, NULL),
 				MTR_MEMO_X_LOCK));
-	ut_ad(mtr_memo_contains_page(mtr, sp_header, MTR_MEMO_PAGE_X_FIX));
+	ut_ad(mtr_memo_contains_page(mtr, sp_header, MTR_MEMO_PAGE_S_FIX)
+	      || mtr_memo_contains_page(mtr, sp_header, MTR_MEMO_PAGE_X_FIX));
 	ut_ad(page_offset(sp_header) == FSP_HEADER_OFFSET);
 	/* Read free limit and space size */
 	limit = mach_read_from_4(sp_header + FSP_FREE_LIMIT);
@@ -779,7 +773,7 @@ is necessary to make the descriptor defined, as they are uninitialized
 above the free limit.
 @return pointer to the extent descriptor, NULL if the page does not
 exist in the space or if the offset exceeds the free limit */
-static __attribute__((nonnull, warn_unused_result))
+static
 xdes_t*
 xdes_get_descriptor(
 /*================*/
@@ -788,7 +782,7 @@ xdes_get_descriptor(
 			or 0 for uncompressed pages */
 	ulint	offset,	/*!< in: page offset; if equal to the free limit,
 			we try to add new extents to the space free list */
-	mtr_t*	mtr)	/*!< in/out: mini-transaction */
+	mtr_t*	mtr)	/*!< in: mtr handle */
 {
 	buf_block_t*	block;
 	fsp_header_t*	sp_header;
@@ -1166,14 +1160,14 @@ fsp_header_get_tablespace_size(void)
 Tries to extend a single-table tablespace so that a page would fit in the
 data file.
 @return	TRUE if success */
-static __attribute__((nonnull, warn_unused_result))
+static
 ibool
 fsp_try_extend_data_file_with_pages(
 /*================================*/
 	ulint		space,		/*!< in: space */
 	ulint		page_no,	/*!< in: page number */
-	fsp_header_t*	header,		/*!< in/out: space header */
-	mtr_t*		mtr)		/*!< in/out: mini-transaction */
+	fsp_header_t*	header,		/*!< in: space header */
+	mtr_t*		mtr)		/*!< in: mtr */
 {
 	ibool	success;
 	ulint	actual_size;
@@ -1198,7 +1192,7 @@ fsp_try_extend_data_file_with_pages(
 /***********************************************************************//**
 Tries to extend the last data file of a tablespace if it is auto-extending.
 @return	FALSE if not auto-extending */
-static __attribute__((nonnull))
+static
 ibool
 fsp_try_extend_data_file(
 /*=====================*/
@@ -1208,8 +1202,8 @@ fsp_try_extend_data_file(
 					the actual file size rounded down to
 					megabyte */
 	ulint		space,		/*!< in: space */
-	fsp_header_t*	header,		/*!< in/out: space header */
-	mtr_t*		mtr)		/*!< in/out: mini-transaction */
+	fsp_header_t*	header,		/*!< in: space header */
+	mtr_t*		mtr)		/*!< in: mtr */
 {
 	ulint	size;
 	ulint	zip_size;
@@ -1345,7 +1339,7 @@ fsp_fill_free_list(
 					then we do not allocate more extents */
 	ulint		space,		/*!< in: space */
 	fsp_header_t*	header,		/*!< in/out: space header */
-	mtr_t*		mtr)		/*!< in/out: mini-transaction */
+	mtr_t*		mtr)		/*!< in: mtr */
 {
 	ulint	limit;
 	ulint	size;
@@ -1544,46 +1538,9 @@ fsp_alloc_free_extent(
 }
 
 /**********************************************************************//**
-Allocates a single free page from a space. */
-static __attribute__((nonnull))
-void
-fsp_alloc_from_free_frag(
-/*=====================*/
-	fsp_header_t*	header,	/*!< in/out: tablespace header */
-	xdes_t*		descr,	/*!< in/out: extent descriptor */
-	ulint		bit,	/*!< in: slot to allocate in the extent */
-	mtr_t*		mtr)	/*!< in/out: mini-transaction */
-{
-	ulint		frag_n_used;
-
-	ut_ad(xdes_get_state(descr, mtr) == XDES_FREE_FRAG);
-	ut_a(xdes_get_bit(descr, XDES_FREE_BIT, bit, mtr));
-	xdes_set_bit(descr, XDES_FREE_BIT, bit, FALSE, mtr);
-
-	/* Update the FRAG_N_USED field */
-	frag_n_used = mtr_read_ulint(header + FSP_FRAG_N_USED, MLOG_4BYTES,
-				     mtr);
-	frag_n_used++;
-	mlog_write_ulint(header + FSP_FRAG_N_USED, frag_n_used, MLOG_4BYTES,
-			 mtr);
-	if (xdes_is_full(descr, mtr)) {
-		/* The fragment is full: move it to another list */
-		flst_remove(header + FSP_FREE_FRAG, descr + XDES_FLST_NODE,
-			    mtr);
-		xdes_set_state(descr, XDES_FULL_FRAG, mtr);
-
-		flst_add_last(header + FSP_FULL_FRAG, descr + XDES_FLST_NODE,
-			      mtr);
-		mlog_write_ulint(header + FSP_FRAG_N_USED,
-				 frag_n_used - FSP_EXTENT_SIZE, MLOG_4BYTES,
-				 mtr);
-	}
-}
-
-/**********************************************************************//**
 Allocates a single free page from a space. The page is marked as used.
 @return	the page offset, FIL_NULL if no page could be allocated */
-static __attribute__((nonnull, warn_unused_result))
+static
 ulint
 fsp_alloc_free_page(
 /*================*/
@@ -1591,22 +1548,19 @@ fsp_alloc_free_page(
 	ulint	zip_size,/*!< in: compressed page size in bytes
 			or 0 for uncompressed pages */
 	ulint	hint,	/*!< in: hint of which page would be desirable */
-	mtr_t*	mtr,	/*!< in/out: mini-transaction */
-	mtr_t*	init_mtr)/*!< in/out: mini-transaction in which the
-			page should be initialized
-			(may be the same as mtr) */
+	mtr_t*	mtr)	/*!< in/out: mini-transaction */
 {
 	fsp_header_t*	header;
 	fil_addr_t	first;
 	xdes_t*		descr;
 	buf_block_t*	block;
 	ulint		free;
+	ulint		frag_n_used;
 	ulint		page_no;
 	ulint		space_size;
 	ibool		success;
 
 	ut_ad(mtr);
-	ut_ad(init_mtr);
 
 	header = fsp_get_space_header(space, zip_size, mtr);
 
@@ -1688,19 +1642,38 @@ fsp_alloc_free_page(
 		}
 	}
 
-	fsp_alloc_from_free_frag(header, descr, free, mtr);
+	xdes_set_bit(descr, XDES_FREE_BIT, free, FALSE, mtr);
+
+	/* Update the FRAG_N_USED field */
+	frag_n_used = mtr_read_ulint(header + FSP_FRAG_N_USED, MLOG_4BYTES,
+				     mtr);
+	frag_n_used++;
+	mlog_write_ulint(header + FSP_FRAG_N_USED, frag_n_used, MLOG_4BYTES,
+			 mtr);
+	if (xdes_is_full(descr, mtr)) {
+		/* The fragment is full: move it to another list */
+		flst_remove(header + FSP_FREE_FRAG, descr + XDES_FLST_NODE,
+			    mtr);
+		xdes_set_state(descr, XDES_FULL_FRAG, mtr);
+
+		flst_add_last(header + FSP_FULL_FRAG, descr + XDES_FLST_NODE,
+			      mtr);
+		mlog_write_ulint(header + FSP_FRAG_N_USED,
+				 frag_n_used - FSP_EXTENT_SIZE, MLOG_4BYTES,
+				 mtr);
+	}
 
 	/* Initialize the allocated page to the buffer pool, so that it can
 	be obtained immediately with buf_page_get without need for a disk
 	read. */
 
-	buf_page_create(space, page_no, zip_size, init_mtr);
+	buf_page_create(space, page_no, zip_size, mtr);
 
-	block = buf_page_get(space, zip_size, page_no, RW_X_LATCH, init_mtr);
+	block = buf_page_get(space, zip_size, page_no, RW_X_LATCH, mtr);
 	buf_block_dbg_add_level(block, SYNC_FSP_PAGE);
 
 	/* Prior contents of the page should be ignored */
-	fsp_init_file_page(block, init_mtr);
+	fsp_init_file_page(block, mtr);
 
 	return(page_no);
 }
@@ -1936,7 +1909,7 @@ fsp_alloc_seg_inode_page(
 	zip_size = dict_table_flags_to_zip_size(
 		mach_read_from_4(FSP_SPACE_FLAGS + space_header));
 
-	page_no = fsp_alloc_free_page(space, zip_size, 0, mtr, mtr);
+	page_no = fsp_alloc_free_page(space, zip_size, 0, mtr);
 
 	if (page_no == FIL_NULL) {
 
@@ -2350,7 +2323,7 @@ fseg_create_general(
 
 	if (page == 0) {
 		page = fseg_alloc_free_page_low(space, zip_size,
-						inode, 0, FSP_UP, mtr, mtr);
+						inode, 0, FSP_UP, mtr);
 
 		if (page == FIL_NULL) {
 
@@ -2606,12 +2579,7 @@ fseg_alloc_free_page_low(
 				inserted there in order, into which
 				direction they go alphabetically: FSP_DOWN,
 				FSP_UP, FSP_NO_DIR */
-	mtr_t*		mtr,	/*!< in/out: mini-transaction */
-	mtr_t*		init_mtr)/*!< in/out: mini-transaction in which the
-				page should be initialized
-				(may be the same as mtr), or NULL if it
-				should not be initialized (the page at hint
-				was previously freed in mtr) */
+	mtr_t*		mtr)	/*!< in/out: mini-transaction */
 {
 	fsp_header_t*	space_header;
 	ulint		space_size;
@@ -2622,6 +2590,7 @@ fseg_alloc_free_page_low(
 	ulint		ret_page;	/*!< the allocated page offset, FIL_NULL
 					if could not be allocated */
 	xdes_t*		ret_descr;	/*!< the extent of the allocated page */
+	ibool		frag_page_allocated = FALSE;
 	ibool		success;
 	ulint		n;
 
@@ -2643,8 +2612,6 @@ fseg_alloc_free_page_low(
 	if (descr == NULL) {
 		/* Hint outside space or too high above free limit: reset
 		hint */
-		ut_a(init_mtr);
-		/* The file space header page is always allocated. */
 		hint = 0;
 		descr = xdes_get_descriptor(space, zip_size, hint, mtr);
 	}
@@ -2656,20 +2623,15 @@ fseg_alloc_free_page_low(
 						   mtr), seg_id))
 	    && (xdes_get_bit(descr, XDES_FREE_BIT,
 			     hint % FSP_EXTENT_SIZE, mtr) == TRUE)) {
-take_hinted_page:
+
 		/* 1. We can take the hinted page
 		=================================*/
 		ret_descr = descr;
 		ret_page = hint;
-		/* Skip the check for extending the tablespace. If the
-		page hint were not within the size of the tablespace,
-		we would have got (descr == NULL) above and reset the hint. */
-		goto got_hinted_page;
 		/*-----------------------------------------------------------*/
-	} else if (xdes_get_state(descr, mtr) == XDES_FREE
-		   && (!init_mtr
-		       || ((reserved - used < reserved / FSEG_FILLFACTOR)
-			   && used >= FSEG_FRAG_LIMIT))) {
+	} else if ((xdes_get_state(descr, mtr) == XDES_FREE)
+		   && ((reserved - used) < reserved / FSEG_FILLFACTOR)
+		   && (used >= FSEG_FRAG_LIMIT)) {
 
 		/* 2. We allocate the free extent from space and can take
 		=========================================================
@@ -2687,20 +2649,8 @@ take_hinted_page:
 		/* Try to fill the segment free list */
 		fseg_fill_free_list(seg_inode, space, zip_size,
 				    hint + FSP_EXTENT_SIZE, mtr);
-		goto take_hinted_page;
-		/*-----------------------------------------------------------*/
-	} else if (!init_mtr) {
-		ut_a(xdes_get_state(descr, mtr) == XDES_FREE_FRAG);
-		fsp_alloc_from_free_frag(space_header, descr,
-					 hint % FSP_EXTENT_SIZE, mtr);
 		ret_page = hint;
-		ret_descr = NULL;
-
-		/* Put the page in the fragment page array of the segment */
-		n = fseg_find_free_frag_page_slot(seg_inode, mtr);
-		ut_a(n != FIL_NULL);
-		fseg_set_nth_frag_page_no(seg_inode, n, ret_page, mtr);
-		goto got_hinted_page;
+		/*-----------------------------------------------------------*/
 	} else if ((direction != FSP_NO_DIR)
 		   && ((reserved - used) < reserved / FSEG_FILLFACTOR)
 		   && (used >= FSEG_FRAG_LIMIT)
@@ -2760,10 +2710,11 @@ take_hinted_page:
 	} else if (used < FSEG_FRAG_LIMIT) {
 		/* 6. We allocate an individual page from the space
 		===================================================*/
-		ret_page = fsp_alloc_free_page(space, zip_size, hint,
-					       mtr, init_mtr);
+		ret_page = fsp_alloc_free_page(space, zip_size, hint, mtr);
 		ret_descr = NULL;
 
+		frag_page_allocated = TRUE;
+
 		if (ret_page != FIL_NULL) {
 			/* Put the page in the fragment page array of the
 			segment */
@@ -2773,10 +2724,6 @@ take_hinted_page:
 			fseg_set_nth_frag_page_no(seg_inode, n, ret_page,
 						  mtr);
 		}
-
-		/* fsp_alloc_free_page() invoked fsp_init_file_page()
-		already. */
-		return(ret_page);
 		/*-----------------------------------------------------------*/
 	} else {
 		/* 7. We allocate a new extent and take its first page
@@ -2824,34 +2771,26 @@ take_hinted_page:
 		}
 	}
 
-got_hinted_page:
-	{
+	if (!frag_page_allocated) {
 		/* Initialize the allocated page to buffer pool, so that it
 		can be obtained immediately with buf_page_get without need
 		for a disk read */
 		buf_block_t*	block;
 		ulint		zip_size = dict_table_flags_to_zip_size(
 			mach_read_from_4(FSP_SPACE_FLAGS + space_header));
-		mtr_t*		block_mtr = init_mtr ? init_mtr : mtr;
 
-		block = buf_page_create(space, ret_page, zip_size, block_mtr);
+		block = buf_page_create(space, ret_page, zip_size, mtr);
 		buf_block_dbg_add_level(block, SYNC_FSP_PAGE);
 
 		if (UNIV_UNLIKELY(block != buf_page_get(space, zip_size,
 							ret_page, RW_X_LATCH,
-							block_mtr))) {
+							mtr))) {
 			ut_error;
 		}
 
-		if (init_mtr) {
-			/* The prior contents of the page should be ignored */
-			fsp_init_file_page(block, init_mtr);
-		}
-	}
+		/* The prior contents of the page should be ignored */
+		fsp_init_file_page(block, mtr);
 
-	/* ret_descr == NULL if the block was allocated from free_frag
-	(XDES_FREE_FRAG) */
-	if (ret_descr != NULL) {
 		/* At this point we know the extent and the page offset.
 		The extent is still in the appropriate list (FSEG_NOT_FULL
 		or FSEG_FREE), and the page is not yet marked as used. */
@@ -2888,11 +2827,7 @@ fseg_alloc_free_page_general(
 				with fsp_reserve_free_extents, then there
 				is no need to do the check for this individual
 				page */
-	mtr_t*		mtr,	/*!< in/out: mini-transaction handle */
-	mtr_t*		init_mtr)/*!< in/out: mtr or another mini-transaction
-				in which the page should be initialized,
-				or NULL if this is a "fake allocation" of
-				a page that was previously freed in mtr */
+	mtr_t*		mtr)	/*!< in/out: mini-transaction */
 {
 	fseg_inode_t*	inode;
 	ulint		space;
@@ -2934,8 +2869,7 @@ fseg_alloc_free_page_general(
 	}
 
 	page_no = fseg_alloc_free_page_low(space, zip_size,
-					   inode, hint, direction,
-					   mtr, init_mtr);
+					   inode, hint, direction, mtr);
 	if (!has_done_reservation) {
 		fil_space_release_free_extents(space, n_reserved);
 	}
@@ -2944,6 +2878,28 @@ fseg_alloc_free_page_general(
 }
 
 /**********************************************************************//**
+Allocates a single free page from a segment. This function implements
+the intelligent allocation strategy which tries to minimize file space
+fragmentation.
+@return	allocated page offset, FIL_NULL if no page could be allocated */
+UNIV_INTERN
+ulint
+fseg_alloc_free_page(
+/*=================*/
+	fseg_header_t*	seg_header,/*!< in: segment header */
+	ulint		hint,	/*!< in: hint of which page would be desirable */
+	byte		direction,/*!< in: if the new page is needed because
+				of an index page split, and records are
+				inserted there in order, into which
+				direction they go alphabetically: FSP_DOWN,
+				FSP_UP, FSP_NO_DIR */
+	mtr_t*		mtr)	/*!< in: mtr handle */
+{
+	return(fseg_alloc_free_page_general(seg_header, hint, direction,
+					    FALSE, mtr));
+}
+
+/**********************************************************************//**
 Checks that we have at least 2 frag pages free in the first extent of a
 single-table tablespace, and they are also physically initialized to the data
 file. That is we have already extended the data file so that those pages are
diff --git a/storage/innodb_plugin/include/btr0btr.h b/storage/innodb_plugin/include/btr0btr.h
index 476ad29adac..c0a038dd21d 100644
--- a/storage/innodb_plugin/include/btr0btr.h
+++ b/storage/innodb_plugin/include/btr0btr.h
@@ -557,12 +557,7 @@ btr_page_alloc(
 					page split is made */
 	ulint		level,		/*!< in: level where the page is placed
 					in the tree */
-	mtr_t*		mtr,		/*!< in/out: mini-transaction
-					for the allocation */
-	mtr_t*		init_mtr)	/*!< in/out: mini-transaction
-					for x-latching and initializing
-					the page */
-	__attribute__((nonnull, warn_unused_result));
+	mtr_t*		mtr);		/*!< in: mtr */
 /**************************************************************//**
 Frees a file page used in an index tree. NOTE: cannot free field external
 storage pages because the page must contain info on its level. */
@@ -585,33 +580,6 @@ btr_page_free_low(
 	buf_block_t*	block,	/*!< in: block to be freed, x-latched */
 	ulint		level,	/*!< in: page level */
 	mtr_t*		mtr);	/*!< in: mtr */
-/**************************************************************//**
-Marks all MTR_MEMO_FREE_CLUST_LEAF pages nonfree or free.
-For invoking btr_store_big_rec_extern_fields() after an update,
-we must temporarily mark freed clustered index pages allocated, so
-that off-page columns will not be allocated from them. Between the
-btr_store_big_rec_extern_fields() and mtr_commit() we have to
-mark the pages free again, so that no pages will be leaked. */
-UNIV_INTERN
-void
-btr_mark_freed_leaves(
-/*==================*/
-	dict_index_t*	index,	/*!< in/out: clustered index */
-	mtr_t*		mtr,	/*!< in/out: mini-transaction */
-	ibool		nonfree)/*!< in: TRUE=mark nonfree, FALSE=mark freed */
-	__attribute__((nonnull));
-#ifdef UNIV_DEBUG
-/**************************************************************//**
-Validates all pages marked MTR_MEMO_FREE_CLUST_LEAF.
-@see btr_mark_freed_leaves()
-@return TRUE */
-UNIV_INTERN
-ibool
-btr_freed_leaves_validate(
-/*======================*/
-	mtr_t*	mtr)	/*!< in: mini-transaction */
-	__attribute__((nonnull, warn_unused_result));
-#endif /* UNIV_DEBUG */
 #ifdef UNIV_BTR_PRINT
 /*************************************************************//**
 Prints size info of a B-tree. */
diff --git a/storage/innodb_plugin/include/btr0cur.h b/storage/innodb_plugin/include/btr0cur.h
index 1d97c5b9452..6094a2a6c7a 100644
--- a/storage/innodb_plugin/include/btr0cur.h
+++ b/storage/innodb_plugin/include/btr0cur.h
@@ -326,6 +326,16 @@ btr_cur_pessimistic_update(
 	que_thr_t*	thr,	/*!< in: query thread */
 	mtr_t*		mtr);	/*!< in: mtr; must be committed before
 				latching any further pages */
+/*****************************************************************
+Commits and restarts a mini-transaction so that it will retain an
+x-lock on index->lock and the cursor page. */
+UNIV_INTERN
+void
+btr_cur_mtr_commit_and_start(
+/*=========================*/
+	btr_cur_t*	cursor,	/*!< in: cursor */
+	mtr_t*		mtr)	/*!< in/out: mini-transaction */
+	__attribute__((nonnull));
 /***********************************************************//**
 Marks a clustered index record deleted. Writes an undo log record to
 undo log on this delete marking. Writes in the trx id field the id
@@ -530,8 +540,6 @@ btr_store_big_rec_extern_fields_func(
 					the "external storage" flags in offsets
 					will not correspond to rec when
 					this function returns */
-	const big_rec_t*big_rec_vec,	/*!< in: vector containing fields
-					to be stored externally */
 #ifdef UNIV_DEBUG
 	mtr_t*		local_mtr,	/*!< in: mtr containing the
 					latch to rec and to the tree */
@@ -540,12 +548,9 @@ btr_store_big_rec_extern_fields_func(
 	ibool		update_in_place,/*! in: TRUE if the record is updated
 					in place (not delete+insert) */
 #endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
-	mtr_t*		alloc_mtr)	/*!< in/out: in an insert, NULL;
-					in an update, local_mtr for
-					allocating BLOB pages and
-					updating BLOB pointers; alloc_mtr
-					must not have freed any leaf pages */
-	__attribute__((nonnull(1,2,3,4,5), warn_unused_result));
+	const big_rec_t*big_rec_vec)	/*!< in: vector containing fields
+					to be stored externally */
+	__attribute__((nonnull));
 
 /** Stores the fields in big_rec_vec to the tablespace and puts pointers to
 them in rec.  The extern flags in rec will have to be set beforehand.
@@ -554,22 +559,21 @@ file segment of the index tree.
 @param index	in: clustered index; MUST be X-latched by mtr
 @param b	in/out: block containing rec; MUST be X-latched by mtr
 @param rec	in/out: clustered index record
-@param offs	in: rec_get_offsets(rec, index);
+@param offsets	in: rec_get_offsets(rec, index);
 		the "external storage" flags in offsets will not be adjusted
-@param big	in: vector containing fields to be stored externally
 @param mtr	in: mini-transaction that holds x-latch on index and b
 @param upd	in: TRUE if the record is updated in place (not delete+insert)
-@param rmtr	in/out: in updates, the mini-transaction that holds rec
+@param big	in: vector containing fields to be stored externally
 @return	DB_SUCCESS or DB_OUT_OF_FILE_SPACE */
 #ifdef UNIV_DEBUG
-# define btr_store_big_rec_extern_fields(index,b,rec,offs,big,mtr,upd,rmtr) \
-	btr_store_big_rec_extern_fields_func(index,b,rec,offs,big,mtr,upd,rmtr)
+# define btr_store_big_rec_extern_fields(index,b,rec,offsets,mtr,upd,big) \
+	btr_store_big_rec_extern_fields_func(index,b,rec,offsets,mtr,upd,big)
 #elif defined UNIV_BLOB_LIGHT_DEBUG
-# define btr_store_big_rec_extern_fields(index,b,rec,offs,big,mtr,upd,rmtr) \
-	btr_store_big_rec_extern_fields_func(index,b,rec,offs,big,upd,rmtr)
+# define btr_store_big_rec_extern_fields(index,b,rec,offsets,mtr,upd,big) \
+	btr_store_big_rec_extern_fields_func(index,b,rec,offsets,upd,big)
 #else
-# define btr_store_big_rec_extern_fields(index,b,rec,offs,big,mtr,upd,rmtr) \
-	btr_store_big_rec_extern_fields_func(index,b,rec,offs,big,rmtr)
+# define btr_store_big_rec_extern_fields(index,b,rec,offsets,mtr,upd,big) \
+	btr_store_big_rec_extern_fields_func(index,b,rec,offsets,big)
 #endif
 
 /*******************************************************************//**
diff --git a/storage/innodb_plugin/include/fsp0fsp.h b/storage/innodb_plugin/include/fsp0fsp.h
index 2221380c9a2..403e1d404a8 100644
--- a/storage/innodb_plugin/include/fsp0fsp.h
+++ b/storage/innodb_plugin/include/fsp0fsp.h
@@ -176,18 +176,19 @@ fseg_n_reserved_pages(
 Allocates a single free page from a segment. This function implements
 the intelligent allocation strategy which tries to minimize
 file space fragmentation.
-@param[in/out] seg_header	segment header
-@param[in] hint			hint of which page would be desirable
-@param[in] direction		if the new page is needed because
+@return	the allocated page offset FIL_NULL if no page could be allocated */
+UNIV_INTERN
+ulint
+fseg_alloc_free_page(
+/*=================*/
+	fseg_header_t*	seg_header, /*!< in: segment header */
+	ulint		hint,	/*!< in: hint of which page would be desirable */
+	byte		direction, /*!< in: if the new page is needed because
 				of an index page split, and records are
 				inserted there in order, into which
 				direction they go alphabetically: FSP_DOWN,
-				FSP_UP, FSP_NO_DIR
-@param[in/out] mtr		mini-transaction
-@return	the allocated page offset FIL_NULL if no page could be allocated */
-#define fseg_alloc_free_page(seg_header, hint, direction, mtr)		\
-	fseg_alloc_free_page_general(seg_header, hint, direction,	\
-				     FALSE, mtr, mtr)
+				FSP_UP, FSP_NO_DIR */
+	mtr_t*		mtr);	/*!< in: mtr handle */
 /**********************************************************************//**
 Allocates a single free page from a segment. This function implements
 the intelligent allocation strategy which tries to minimize file space
@@ -209,11 +210,7 @@ fseg_alloc_free_page_general(
 				with fsp_reserve_free_extents, then there
 				is no need to do the check for this individual
 				page */
-	mtr_t*		mtr,	/*!< in/out: mini-transaction */
-	mtr_t*		init_mtr)/*!< in/out: mtr or another mini-transaction
-				in which the page should be initialized,
-				or NULL if this is a "fake allocation" of
-				a page that was previously freed in mtr */
+	mtr_t*		mtr)	/*!< in/out: mini-transaction */
 	__attribute__((warn_unused_result, nonnull(1,5)));
 /**********************************************************************//**
 Reserves free pages from a tablespace. All mini-transactions which may
diff --git a/storage/innodb_plugin/include/mtr0mtr.h b/storage/innodb_plugin/include/mtr0mtr.h
index 3529519e7f4..8a9ec8ea7f0 100644
--- a/storage/innodb_plugin/include/mtr0mtr.h
+++ b/storage/innodb_plugin/include/mtr0mtr.h
@@ -53,8 +53,6 @@ first 3 values must be RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */
 #define MTR_MEMO_MODIFY		54
 #define	MTR_MEMO_S_LOCK		55
 #define	MTR_MEMO_X_LOCK		56
-/** The mini-transaction freed a clustered index leaf page. */
-#define MTR_MEMO_FREE_CLUST_LEAF	57
 
 /** @name Log item types
 The log items are declared 'byte' so that the compiler can warn if val
@@ -379,12 +377,9 @@ struct mtr_struct{
 #endif
 	dyn_array_t	memo;	/*!< memo stack for locks etc. */
 	dyn_array_t	log;	/*!< mini-transaction log */
-	unsigned	modifications:1;
-				/*!< TRUE if the mini-transaction
-				modified buffer pool pages */
-	unsigned	freed_clust_leaf:1;
-				/*!< TRUE if MTR_MEMO_FREE_CLUST_LEAF
-				was logged in the mini-transaction */
+	ibool		modifications;
+				/* TRUE if the mtr made modifications to
+				buffer pool pages */
 	ulint		n_log_recs;
 				/* count of how many page initial log records
 				have been written to the mtr log */
diff --git a/storage/innodb_plugin/include/mtr0mtr.ic b/storage/innodb_plugin/include/mtr0mtr.ic
index 9c0ddff9132..9f92d2b06a1 100644
--- a/storage/innodb_plugin/include/mtr0mtr.ic
+++ b/storage/innodb_plugin/include/mtr0mtr.ic
@@ -44,7 +44,6 @@ mtr_start(
 
 	mtr->log_mode = MTR_LOG_ALL;
 	mtr->modifications = FALSE;
-	mtr->freed_clust_leaf = FALSE;
 	mtr->n_log_recs = 0;
 
 	ut_d(mtr->state = MTR_ACTIVE);
@@ -68,8 +67,7 @@ mtr_memo_push(
 
 	ut_ad(object);
 	ut_ad(type >= MTR_MEMO_PAGE_S_FIX);
-	ut_ad(type <= MTR_MEMO_FREE_CLUST_LEAF);
-	ut_ad(type != MTR_MEMO_FREE_CLUST_LEAF || mtr->freed_clust_leaf);
+	ut_ad(type <= MTR_MEMO_X_LOCK);
 	ut_ad(mtr);
 	ut_ad(mtr->magic_n == MTR_MAGIC_N);
 	ut_ad(mtr->state == MTR_ACTIVE);
diff --git a/storage/innodb_plugin/mtr/mtr0mtr.c b/storage/innodb_plugin/mtr/mtr0mtr.c
index e3fefbedec7..5fad61b2922 100644
--- a/storage/innodb_plugin/mtr/mtr0mtr.c
+++ b/storage/innodb_plugin/mtr/mtr0mtr.c
@@ -58,11 +58,12 @@ mtr_memo_slot_release(
 			buf_page_release((buf_block_t*)object, type, mtr);
 		} else if (type == MTR_MEMO_S_LOCK) {
 			rw_lock_s_unlock((rw_lock_t*)object);
+#ifdef UNIV_DEBUG
 		} else if (type != MTR_MEMO_X_LOCK) {
-			ut_ad(type == MTR_MEMO_MODIFY
-			      || type == MTR_MEMO_FREE_CLUST_LEAF);
+			ut_ad(type == MTR_MEMO_MODIFY);
 			ut_ad(mtr_memo_contains(mtr, object,
 						MTR_MEMO_PAGE_X_FIX));
+#endif /* UNIV_DEBUG */
 		} else {
 			rw_lock_x_unlock((rw_lock_t*)object);
 		}
diff --git a/storage/innodb_plugin/row/row0ins.c b/storage/innodb_plugin/row/row0ins.c
index cd135e8ba8f..f0f6eca627f 100644
--- a/storage/innodb_plugin/row/row0ins.c
+++ b/storage/innodb_plugin/row/row0ins.c
@@ -2097,20 +2097,15 @@ row_ins_index_entry_low(
 			if (big_rec) {
 				ut_a(err == DB_SUCCESS);
 				/* Write out the externally stored
-				columns, but allocate the pages and
-				write the pointers using the
-				mini-transaction of the record update.
-				If any pages were freed in the update,
-				temporarily mark them allocated so
-				that off-page columns will not
-				overwrite them. We must do this,
-				because we will write the redo log for
-				the BLOB writes before writing the
-				redo log for the record update. Thus,
-				redo log application at crash recovery
-				will see BLOBs being written to free pages. */
-
-				btr_mark_freed_leaves(index, &mtr, TRUE);
+				columns while still x-latching
+				index->lock and block->lock. We have
+				to mtr_commit(mtr) first, so that the
+				redo log will be written in the
+				correct order. Otherwise, we would run
+				into trouble on crash recovery if mtr
+				freed B-tree pages on which some of
+				the big_rec fields will be written. */
+				btr_cur_mtr_commit_and_start(&cursor, &mtr);
 
 				rec = btr_cur_get_rec(&cursor);
 				offsets = rec_get_offsets(
@@ -2119,8 +2114,7 @@ row_ins_index_entry_low(
 
 				err = btr_store_big_rec_extern_fields(
 					index, btr_cur_get_block(&cursor),
-					rec, offsets, big_rec, &mtr,
-					FALSE, &mtr);
+					rec, offsets, &mtr, FALSE, big_rec);
 				/* If writing big_rec fails (for
 				example, because of DB_OUT_OF_FILE_SPACE),
 				the record will be corrupted. Even if
@@ -2133,9 +2127,6 @@ row_ins_index_entry_low(
 				undo log, and thus the record cannot
 				be rolled back. */
 				ut_a(err == DB_SUCCESS);
-				/* Free the pages again
-				in order to avoid a leak. */
-				btr_mark_freed_leaves(index, &mtr, FALSE);
 				goto stored_big_rec;
 			}
 		} else {
@@ -2177,7 +2168,7 @@ function_exit:
 
 		err = btr_store_big_rec_extern_fields(
 			index, btr_cur_get_block(&cursor),
-			rec, offsets, big_rec, &mtr, FALSE, NULL);
+			rec, offsets, &mtr, FALSE, big_rec);
 
 stored_big_rec:
 		if (modify) {
diff --git a/storage/innodb_plugin/row/row0row.c b/storage/innodb_plugin/row/row0row.c
index e476ffae84e..9cdbbe76e04 100644
--- a/storage/innodb_plugin/row/row0row.c
+++ b/storage/innodb_plugin/row/row0row.c
@@ -243,20 +243,19 @@ row_build(
 	}
 
 #if defined UNIV_DEBUG || defined UNIV_BLOB_LIGHT_DEBUG
-	if (rec_offs_any_null_extern(rec, offsets)) {
-		/* This condition can occur during crash recovery
-		before trx_rollback_active() has completed execution.
-
-		This condition is possible if the server crashed
-		during an insert or update-by-delete-and-insert before
-		btr_store_big_rec_extern_fields() did mtr_commit() all
-		BLOB pointers to the freshly inserted clustered index
-		record. */
-		ut_a(trx_assert_recovered(
-			     row_get_rec_trx_id(rec, index, offsets)));
-		ut_a(trx_undo_roll_ptr_is_insert(
-			     row_get_rec_roll_ptr(rec, index, offsets)));
-	}
+	/* This condition can occur during crash recovery before
+	trx_rollback_active() has completed execution.
+
+	This condition is possible if the server crashed
+	during an insert or update before
+	btr_store_big_rec_extern_fields() did mtr_commit() all
+	BLOB pointers to the clustered index record.
+
+	If the record contains a null BLOB pointer, look up the
+	transaction that holds the implicit lock on this record, and
+	assert that it was recovered (and will soon be rolled back). */
+	ut_a(!rec_offs_any_null_extern(rec, offsets)
+	     || trx_assert_recovered(row_get_rec_trx_id(rec, index, offsets)));
 #endif /* UNIV_DEBUG || UNIV_BLOB_LIGHT_DEBUG */
 
 	if (type != ROW_COPY_POINTERS) {
diff --git a/storage/innodb_plugin/row/row0upd.c b/storage/innodb_plugin/row/row0upd.c
index 05856687015..b5952ff0a78 100644
--- a/storage/innodb_plugin/row/row0upd.c
+++ b/storage/innodb_plugin/row/row0upd.c
@@ -1978,22 +1978,21 @@ row_upd_clust_rec(
 		rec_offs_init(offsets_);
 
 		ut_a(err == DB_SUCCESS);
-		/* Write out the externally stored columns, but
-		allocate the pages and write the pointers using the
-		mini-transaction of the record update. If any pages
-		were freed in the update, temporarily mark them
-		allocated so that off-page columns will not overwrite
-		them. We must do this, because we write the redo log
-		for the BLOB writes before writing the redo log for
-		the record update. */
-
-		btr_mark_freed_leaves(index, mtr, TRUE);
+		/* Write out the externally stored columns while still
+		x-latching index->lock and block->lock. We have to
+		mtr_commit(mtr) first, so that the redo log will be
+		written in the correct order. Otherwise, we would run
+		into trouble on crash recovery if mtr freed B-tree
+		pages on which some of the big_rec fields will be
+		written. */
+		btr_cur_mtr_commit_and_start(btr_cur, mtr);
+
 		rec = btr_cur_get_rec(btr_cur);
 		err = btr_store_big_rec_extern_fields(
 			index, btr_cur_get_block(btr_cur), rec,
 			rec_get_offsets(rec, index, offsets_,
 					ULINT_UNDEFINED, &heap),
-			big_rec, mtr, TRUE, mtr);
+			mtr, TRUE, big_rec);
 		/* If writing big_rec fails (for example, because of
 		DB_OUT_OF_FILE_SPACE), the record will be corrupted.
 		Even if we did not update any externally stored
@@ -2003,8 +2002,6 @@ row_upd_clust_rec(
 		to the undo log, and thus the record cannot be rolled
 		back. */
 		ut_a(err == DB_SUCCESS);
-		/* Free the pages again in order to avoid a leak. */
-		btr_mark_freed_leaves(index, mtr, FALSE);
 	}
 
 	mtr_commit(mtr);
diff --git a/storage/innodb_plugin/trx/trx0undo.c b/storage/innodb_plugin/trx/trx0undo.c
index c36f55fbd9c..746f0808643 100644
--- a/storage/innodb_plugin/trx/trx0undo.c
+++ b/storage/innodb_plugin/trx/trx0undo.c
@@ -912,7 +912,7 @@ trx_undo_add_page(
 	page_no = fseg_alloc_free_page_general(header_page + TRX_UNDO_SEG_HDR
 					       + TRX_UNDO_FSEG_HEADER,
 					       undo->top_page_no + 1, FSP_UP,
-					       TRUE, mtr, mtr);
+					       TRUE, mtr);
 
 	fil_space_release_free_extents(undo->space, n_reserved);