diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index fc0f41dbf90b..d85fd5c8a2c4 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3155,6 +3155,7 @@ extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
 				struct inode *inode2, ext4_lblk_t lblk1,
 			     ext4_lblk_t lblk2,  ext4_lblk_t count,
 			     int mark_unwritten,int *err);
+extern int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu);
 
 /* move_extent.c */
 extern void ext4_double_down_write_data_sem(struct inode *first,
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 95796f00e4e6..26481e543312 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5930,3 +5930,82 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1,
 	}
 	return replaced_count;
 }
+
+/*
+ * ext4_clu_mapped - determine whether any block in a logical cluster has
+ *                   been mapped to a physical cluster
+ *
+ * @inode - file containing the logical cluster
+ * @lclu - logical cluster of interest
+ *
+ * Returns 1 if any block in the logical cluster is mapped, signifying
+ * that a physical cluster has been allocated for it.  Otherwise,
+ * returns 0.  Can also return negative error codes.  Derived from
+ * ext4_ext_map_blocks().
+ */
+int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct ext4_ext_path *path;
+	int depth, mapped = 0, err = 0;
+	struct ext4_extent *extent;
+	ext4_lblk_t first_lblk, first_lclu, last_lclu;
+
+	/* search for the extent closest to the first block in the cluster */
+	path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
+	if (IS_ERR(path)) {
+		err = PTR_ERR(path);
+		path = NULL;
+		goto out;
+	}
+
+	depth = ext_depth(inode);
+
+	/*
+	 * A consistent leaf must not be empty.  This situation is possible,
+	 * though, _during_ tree modification, and it's why an assert can't
+	 * be put in ext4_find_extent().
+	 */
+	if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
+		EXT4_ERROR_INODE(inode,
+		    "bad extent address - lblock: %lu, depth: %d, pblock: %lld",
+				 (unsigned long) EXT4_C2B(sbi, lclu),
+				 depth, path[depth].p_block);
+		err = -EFSCORRUPTED;
+		goto out;
+	}
+
+	extent = path[depth].p_ext;
+
+	/* can't be mapped if the extent tree is empty */
+	if (extent == NULL)
+		goto out;
+
+	first_lblk = le32_to_cpu(extent->ee_block);
+	first_lclu = EXT4_B2C(sbi, first_lblk);
+
+	/*
+	 * Three possible outcomes at this point - found extent spanning
+	 * the target cluster, to the left of the target cluster, or to the
+	 * right of the target cluster.  The first two cases are handled here.
+	 * The last case indicates the target cluster is not mapped.
+	 */
+	if (lclu >= first_lclu) {
+		last_lclu = EXT4_B2C(sbi, first_lblk +
+				     ext4_ext_get_actual_len(extent) - 1);
+		if (lclu <= last_lclu) {
+			mapped = 1;
+		} else {
+			first_lblk = ext4_ext_next_allocated_block(path);
+			first_lclu = EXT4_B2C(sbi, first_lblk);
+			if (lclu == first_lclu)
+				mapped = 1;
+		}
+	}
+
+out:
+	ext4_ext_drop_refs(path);
+	kfree(path);
+
+	return err ? err : mapped;
+}
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 194785ce890a..c5d456e12062 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -1552,3 +1552,56 @@ bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk)
 
 	return ret;
 }
+
+/*
+ * ext4_es_insert_delayed_block - adds a delayed block to the extents status
+ *                                tree, adding a pending reservation where
+ *                                needed
+ *
+ * @inode - file containing the newly added block
+ * @lblk - logical block to be added
+ * @allocated - indicates whether a physical cluster has been allocated for
+ *              the logical cluster that contains the block
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
+				 bool allocated)
+{
+	struct extent_status newes;
+	int err = 0;
+
+	es_debug("add [%u/1) delayed to extent status tree of inode %lu\n",
+		 lblk, inode->i_ino);
+
+	newes.es_lblk = lblk;
+	newes.es_len = 1;
+	ext4_es_store_pblock_status(&newes, ~0, EXTENT_STATUS_DELAYED);
+	trace_ext4_es_insert_delayed_block(inode, &newes, allocated);
+
+	ext4_es_insert_extent_check(inode, &newes);
+
+	write_lock(&EXT4_I(inode)->i_es_lock);
+
+	err = __es_remove_extent(inode, lblk, lblk);
+	if (err != 0)
+		goto error;
+retry:
+	err = __es_insert_extent(inode, &newes);
+	if (err == -ENOMEM && __es_shrink(EXT4_SB(inode->i_sb),
+					  128, EXT4_I(inode)))
+		goto retry;
+	if (err != 0)
+		goto error;
+
+	if (allocated)
+		__insert_pending(inode, lblk);
+
+error:
+	write_unlock(&EXT4_I(inode)->i_es_lock);
+
+	ext4_es_print_tree(inode);
+	ext4_print_pending_tree(inode);
+
+	return err;
+}
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index 379b7171c67c..9d3c676ec623 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -178,6 +178,16 @@ static inline int ext4_es_is_hole(struct extent_status *es)
 	return (ext4_es_type(es) & EXTENT_STATUS_HOLE) != 0;
 }
 
+static inline int ext4_es_is_mapped(struct extent_status *es)
+{
+	return (ext4_es_is_written(es) || ext4_es_is_unwritten(es));
+}
+
+static inline int ext4_es_is_delonly(struct extent_status *es)
+{
+	return (ext4_es_is_delayed(es) && !ext4_es_is_unwritten(es));
+}
+
 static inline void ext4_es_set_referenced(struct extent_status *es)
 {
 	es->es_pblk |= ((ext4_fsblk_t)EXTENT_STATUS_REFERENCED) << ES_SHIFT;
@@ -232,5 +242,7 @@ extern void ext4_exit_pending(void);
 extern void ext4_init_pending_tree(struct ext4_pending_tree *tree);
 extern void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk);
 extern bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk);
+extern int ext4_es_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk,
+					bool allocated);
 
 #endif /* _EXT4_EXTENTS_STATUS_H */
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b83bf3308b5e..57c6dd38f071 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1780,6 +1780,65 @@ static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
 	return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
 }
 
+/*
+ * ext4_insert_delayed_block - adds a delayed block to the extents status
+ *                             tree, incrementing the reserved cluster/block
+ *                             count or making a pending reservation
+ *                             where needed
+ *
+ * @inode - file containing the newly added block
+ * @lblk - logical block to be added
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
+static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	int ret;
+	bool allocated = false;
+
+	/*
+	 * If the cluster containing lblk is shared with a delayed,
+	 * written, or unwritten extent in a bigalloc file system, it's
+	 * already been accounted for and does not need to be reserved.
+	 * A pending reservation must be made for the cluster if it's
+	 * shared with a written or unwritten extent and doesn't already
+	 * have one.  Written and unwritten extents can be purged from the
+	 * extents status tree if the system is under memory pressure, so
+	 * it's necessary to examine the extent tree if a search of the
+	 * extents status tree doesn't get a match.
+	 */
+	if (sbi->s_cluster_ratio == 1) {
+		ret = ext4_da_reserve_space(inode);
+		if (ret != 0)   /* ENOSPC */
+			goto errout;
+	} else {   /* bigalloc */
+		if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) {
+			if (!ext4_es_scan_clu(inode,
+					      &ext4_es_is_mapped, lblk)) {
+				ret = ext4_clu_mapped(inode,
+						      EXT4_B2C(sbi, lblk));
+				if (ret < 0)
+					goto errout;
+				if (ret == 0) {
+					ret = ext4_da_reserve_space(inode);
+					if (ret != 0)   /* ENOSPC */
+						goto errout;
+				} else {
+					allocated = true;
+				}
+			} else {
+				allocated = true;
+			}
+		}
+	}
+
+	ret = ext4_es_insert_delayed_block(inode, lblk, allocated);
+
+errout:
+	return ret;
+}
+
 /*
  * This function is grabs code from the very beginning of
  * ext4_map_blocks, but assumes that the caller is from delayed write
@@ -1864,25 +1923,9 @@ add_delayed:
 		 * XXX: __block_prepare_write() unmaps passed block,
 		 * is it OK?
 		 */
-		/*
-		 * If the block was allocated from previously allocated cluster,
-		 * then we don't need to reserve it again. However we still need
-		 * to reserve metadata for every block we're going to write.
-		 */
-		if (EXT4_SB(inode->i_sb)->s_cluster_ratio == 1 ||
-		    !ext4_es_scan_clu(inode,
-				      &ext4_es_is_delayed, map->m_lblk)) {
-			ret = ext4_da_reserve_space(inode);
-			if (ret) {
-				/* not enough space to reserve */
-				retval = ret;
-				goto out_unlock;
-			}
-		}
 
-		ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
-					    ~0, EXTENT_STATUS_DELAYED);
-		if (ret) {
+		ret = ext4_insert_delayed_block(inode, map->m_lblk);
+		if (ret != 0) {
 			retval = ret;
 			goto out_unlock;
 		}
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index 7849b7f8fd9d..6d7a943f849c 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -2512,6 +2512,41 @@ TRACE_EVENT(ext4_es_shrink,
 		  __entry->scan_time, __entry->nr_skipped, __entry->retried)
 );
 
+TRACE_EVENT(ext4_es_insert_delayed_block,
+	TP_PROTO(struct inode *inode, struct extent_status *es,
+		 bool allocated),
+
+	TP_ARGS(inode, es, allocated),
+
+	TP_STRUCT__entry(
+		__field(	dev_t,		dev		)
+		__field(	ino_t,		ino		)
+		__field(	ext4_lblk_t,	lblk		)
+		__field(	ext4_lblk_t,	len		)
+		__field(	ext4_fsblk_t,	pblk		)
+		__field(	char,		status		)
+		__field(	bool,		allocated	)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= inode->i_sb->s_dev;
+		__entry->ino		= inode->i_ino;
+		__entry->lblk		= es->es_lblk;
+		__entry->len		= es->es_len;
+		__entry->pblk		= ext4_es_pblock(es);
+		__entry->status		= ext4_es_status(es);
+		__entry->allocated	= allocated;
+	),
+
+	TP_printk("dev %d,%d ino %lu es [%u/%u) mapped %llu status %s "
+		  "allocated %d",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  (unsigned long) __entry->ino,
+		  __entry->lblk, __entry->len,
+		  __entry->pblk, show_extent_status(__entry->status),
+		  __entry->allocated)
+);
+
 /* fsmap traces */
 DECLARE_EVENT_CLASS(ext4_fsmap_class,
 	TP_PROTO(struct super_block *sb, u32 keydev, u32 agno, u64 bno, u64 len,