diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 55d6d1c36b62..c912ee26e85d 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -3015,8 +3015,8 @@ void check_system_chunk(struct btrfs_trans_handle *trans, u64 type)
 	num_devs = get_profile_num_devs(fs_info, type);
 
 	/* num_devs device items to update and 1 chunk item to add or remove */
-	thresh = btrfs_calc_trunc_metadata_size(fs_info, num_devs) +
-		btrfs_calc_trans_metadata_size(fs_info, 1);
+	thresh = btrfs_calc_metadata_size(fs_info, num_devs) +
+		btrfs_calc_insert_metadata_size(fs_info, 1);
 
 	if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) {
 		btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu",
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 20793742c9d3..d27b39858339 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2451,17 +2451,21 @@ u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset);
 
 u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes);
 
-static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_fs_info *fs_info,
-						 unsigned num_items)
+/*
+ * Use this if we would be adding new items, as we could split nodes as we cow
+ * down the tree.
+ */
+static inline u64 btrfs_calc_insert_metadata_size(struct btrfs_fs_info *fs_info,
+						  unsigned num_items)
 {
 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
 }
 
 /*
- * Doing a truncate won't result in new nodes or leaves, just what we need for
- * COW.
+ * Doing a truncate or a modification won't result in new nodes or leaves, just
+ * what we need for COW.
  */
-static inline u64 btrfs_calc_trunc_metadata_size(struct btrfs_fs_info *fs_info,
+static inline u64 btrfs_calc_metadata_size(struct btrfs_fs_info *fs_info,
 						 unsigned num_items)
 {
 	return (u64)fs_info->nodesize * BTRFS_MAX_LEVEL * num_items;
diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
index d2dfc201b2e1..62aa18b38a08 100644
--- a/fs/btrfs/delalloc-space.c
+++ b/fs/btrfs/delalloc-space.c
@@ -256,12 +256,12 @@ static void btrfs_calculate_inode_block_rsv_size(struct btrfs_fs_info *fs_info,
 	lockdep_assert_held(&inode->lock);
 	outstanding_extents = inode->outstanding_extents;
 	if (outstanding_extents)
-		reserve_size = btrfs_calc_trans_metadata_size(fs_info,
+		reserve_size = btrfs_calc_insert_metadata_size(fs_info,
 						outstanding_extents + 1);
 	csum_leaves = btrfs_csum_bytes_to_leaves(fs_info,
 						 inode->csum_bytes);
-	reserve_size += btrfs_calc_trans_metadata_size(fs_info,
-						       csum_leaves);
+	reserve_size += btrfs_calc_insert_metadata_size(fs_info,
+							csum_leaves);
 	/*
 	 * For qgroup rsv, the calculation is very simple:
 	 * account one nodesize for each outstanding extent
@@ -284,7 +284,7 @@ static void calc_inode_reservations(struct btrfs_fs_info *fs_info,
 	u64 csum_leaves = btrfs_csum_bytes_to_leaves(fs_info, num_bytes);
 
 	/* We add one for the inode update at finish ordered time */
-	*meta_reserve = btrfs_calc_trans_metadata_size(fs_info,
+	*meta_reserve = btrfs_calc_insert_metadata_size(fs_info,
 						nr_extents + csum_leaves + 1);
 	*qgroup_reserve = nr_extents * fs_info->nodesize;
 }
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 6858a05606dd..de87ea7ce84d 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -558,7 +558,7 @@ static int btrfs_delayed_item_reserve_metadata(struct btrfs_trans_handle *trans,
 	src_rsv = trans->block_rsv;
 	dst_rsv = &fs_info->delayed_block_rsv;
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 
 	/*
 	 * Here we migrate space rsv from transaction rsv, since have already
@@ -612,7 +612,7 @@ static int btrfs_delayed_inode_reserve_metadata(
 	src_rsv = trans->block_rsv;
 	dst_rsv = &fs_info->delayed_block_rsv;
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 
 	/*
 	 * btrfs_dirty_inode will update the inode under btrfs_join_transaction
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 9a91d1eb0af4..951a60c740e7 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -79,7 +79,7 @@ int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans)
 void btrfs_delayed_refs_rsv_release(struct btrfs_fs_info *fs_info, int nr)
 {
 	struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
-	u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, nr);
+	u64 num_bytes = btrfs_calc_insert_metadata_size(fs_info, nr);
 	u64 released = 0;
 
 	released = __btrfs_block_rsv_release(fs_info, block_rsv, num_bytes,
@@ -105,8 +105,8 @@ void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans)
 	if (!trans->delayed_ref_updates)
 		return;
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info,
-						   trans->delayed_ref_updates);
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info,
+						    trans->delayed_ref_updates);
 	spin_lock(&delayed_rsv->lock);
 	delayed_rsv->size += num_bytes;
 	delayed_rsv->full = 0;
@@ -174,7 +174,7 @@ int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
 				  enum btrfs_reserve_flush_enum flush)
 {
 	struct btrfs_block_rsv *block_rsv = &fs_info->delayed_refs_rsv;
-	u64 limit = btrfs_calc_trans_metadata_size(fs_info, 1);
+	u64 limit = btrfs_calc_insert_metadata_size(fs_info, 1);
 	u64 num_bytes = 0;
 	int ret = -ENOSPC;
 
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index b31991f0f440..1cb694c96500 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2511,7 +2511,7 @@ int btrfs_punch_hole_range(struct inode *inode, struct btrfs_path *path,
 			   struct btrfs_trans_handle **trans_out)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-	u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1);
+	u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
 	u64 ino_size = round_up(inode->i_size, fs_info->sectorsize);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_trans_handle *trans = NULL;
@@ -2530,7 +2530,7 @@ int btrfs_punch_hole_range(struct inode *inode, struct btrfs_path *path,
 		ret = -ENOMEM;
 		goto out;
 	}
-	rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1);
+	rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
 	rsv->failfast = 1;
 
 	/*
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index faaf57a7c289..265dc75f7a7a 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -211,8 +211,8 @@ int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
 	int ret;
 
 	/* 1 for slack space, 1 for updating the inode */
-	needed_bytes = btrfs_calc_trunc_metadata_size(fs_info, 1) +
-		btrfs_calc_trans_metadata_size(fs_info, 1);
+	needed_bytes = btrfs_calc_insert_metadata_size(fs_info, 1) +
+		btrfs_calc_metadata_size(fs_info, 1);
 
 	spin_lock(&rsv->lock);
 	if (rsv->reserved < needed_bytes)
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 86031cdfc356..63cad7865d75 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -436,7 +436,7 @@ int btrfs_save_ino_cache(struct btrfs_root *root,
 	 * 1 item for free space object
 	 * 3 items for pre-allocation
 	 */
-	trans->bytes_reserved = btrfs_calc_trans_metadata_size(fs_info, 10);
+	trans->bytes_reserved = btrfs_calc_insert_metadata_size(fs_info, 10);
 	ret = btrfs_block_rsv_add(root, trans->block_rsv,
 				  trans->bytes_reserved,
 				  BTRFS_RESERVE_NO_FLUSH);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c4116bc58827..31eacbf51d4e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5337,7 +5337,7 @@ static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
 	struct btrfs_trans_handle *trans;
-	u64 delayed_refs_extra = btrfs_calc_trans_metadata_size(fs_info, 1);
+	u64 delayed_refs_extra = btrfs_calc_insert_metadata_size(fs_info, 1);
 	int ret;
 
 	/*
@@ -5426,7 +5426,7 @@ void btrfs_evict_inode(struct inode *inode)
 	rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
 	if (!rsv)
 		goto no_delete;
-	rsv->size = btrfs_calc_trunc_metadata_size(fs_info, 1);
+	rsv->size = btrfs_calc_metadata_size(fs_info, 1);
 	rsv->failfast = 1;
 
 	btrfs_i_size_write(BTRFS_I(inode), 0);
@@ -9040,7 +9040,7 @@ static int btrfs_truncate(struct inode *inode, bool skip_writeback)
 	int ret;
 	struct btrfs_trans_handle *trans;
 	u64 mask = fs_info->sectorsize - 1;
-	u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
+	u64 min_size = btrfs_calc_metadata_size(fs_info, 1);
 
 	if (!skip_writeback) {
 		ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index e0469816c678..1e664e0b59b8 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -362,7 +362,7 @@ static int inherit_props(struct btrfs_trans_handle *trans,
 		 * reservations if we do add more properties in the future.
 		 */
 		if (need_reserve) {
-			num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
+			num_bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 			ret = btrfs_block_rsv_add(root, trans->block_rsv,
 					num_bytes, BTRFS_RESERVE_NO_FLUSH);
 			if (ret)
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 47733fb55df7..3b17b647d002 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -533,7 +533,7 @@ int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
 			return ret;
 	}
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, items);
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info, items);
 	rsv->space_info = btrfs_find_space_info(fs_info,
 					    BTRFS_BLOCK_GROUP_METADATA);
 	ret = btrfs_block_rsv_add(root, rsv, num_bytes,
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 5f8f65599de1..13a4326c8821 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -412,7 +412,7 @@ static inline u64 calc_reclaim_items_nr(struct btrfs_fs_info *fs_info,
 	u64 bytes;
 	u64 nr;
 
-	bytes = btrfs_calc_trans_metadata_size(fs_info, 1);
+	bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
 	nr = div64_u64(to_reclaim, bytes);
 	if (!nr)
 		nr = 1;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 2e3f6778bfa3..f21416d68c2c 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -485,7 +485,7 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
 		 * worth of delayed refs updates in this trans handle, and
 		 * refill that amount for whatever is missing in the reserve.
 		 */
-		num_bytes = btrfs_calc_trans_metadata_size(fs_info, num_items);
+		num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items);
 		if (delayed_refs_rsv->full == 0) {
 			delayed_refs_bytes = num_bytes;
 			num_bytes <<= 1;
@@ -636,7 +636,7 @@ struct btrfs_trans_handle *btrfs_start_transaction_fallback_global_rsv(
 	if (IS_ERR(trans))
 		return trans;
 
-	num_bytes = btrfs_calc_trans_metadata_size(fs_info, num_items);
+	num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items);
 	ret = btrfs_cond_migrate_bytes(fs_info, &fs_info->trans_block_rsv,
 				       num_bytes, min_factor);
 	if (ret) {