diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 24a048210b15..955ce300e5a1 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -252,8 +252,6 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
 			em->len += merge->len;
 			em->block_len += merge->block_len;
 			em->block_start = merge->block_start;
-			em->mod_len = (em->mod_len + em->mod_start) - merge->mod_start;
-			em->mod_start = merge->mod_start;
 			em->generation = max(em->generation, merge->generation);
 			em->flags |= EXTENT_FLAG_MERGED;
 
@@ -271,7 +269,6 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
 		em->block_len += merge->block_len;
 		rb_erase_cached(&merge->rb_node, &tree->map);
 		RB_CLEAR_NODE(&merge->rb_node);
-		em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
 		em->generation = max(em->generation, merge->generation);
 		em->flags |= EXTENT_FLAG_MERGED;
 		free_extent_map(merge);
@@ -300,7 +297,6 @@ int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen)
 	struct extent_map_tree *tree = &inode->extent_tree;
 	int ret = 0;
 	struct extent_map *em;
-	bool prealloc = false;
 
 	write_lock(&tree->lock);
 	em = lookup_extent_mapping(tree, start, len);
@@ -325,21 +321,9 @@ int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen)
 
 	em->generation = gen;
 	em->flags &= ~EXTENT_FLAG_PINNED;
-	em->mod_start = em->start;
-	em->mod_len = em->len;
-
-	if (em->flags & EXTENT_FLAG_FILLING) {
-		prealloc = true;
-		em->flags &= ~EXTENT_FLAG_FILLING;
-	}
 
 	try_merge_map(tree, em);
 
-	if (prealloc) {
-		em->mod_start = em->start;
-		em->mod_len = em->len;
-	}
-
 out:
 	write_unlock(&tree->lock);
 	free_extent_map(em);
@@ -361,8 +345,6 @@ static inline void setup_extent_mapping(struct extent_map_tree *tree,
 					int modified)
 {
 	refcount_inc(&em->refs);
-	em->mod_start = em->start;
-	em->mod_len = em->len;
 
 	ASSERT(list_empty(&em->list));
 
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index c5a098c99cc6..10e9491865c9 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -30,8 +30,6 @@ enum {
 	ENUM_BIT(EXTENT_FLAG_PREALLOC),
 	/* Logging this extent */
 	ENUM_BIT(EXTENT_FLAG_LOGGING),
-	/* Filling in a preallocated extent */
-	ENUM_BIT(EXTENT_FLAG_FILLING),
 	/* This em is merged from two or more physically adjacent ems */
 	ENUM_BIT(EXTENT_FLAG_MERGED),
 };
@@ -46,8 +44,6 @@ struct extent_map {
 	/* all of these are in bytes */
 	u64 start;
 	u64 len;
-	u64 mod_start;
-	u64 mod_len;
 	u64 orig_start;
 	u64 orig_block_len;
 	u64 ram_bytes;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 15a13e191ee7..12b1a83a4303 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7337,9 +7337,7 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
 	em->ram_bytes = ram_bytes;
 	em->generation = -1;
 	em->flags |= EXTENT_FLAG_PINNED;
-	if (type == BTRFS_ORDERED_PREALLOC)
-		em->flags |= EXTENT_FLAG_FILLING;
-	else if (type == BTRFS_ORDERED_COMPRESSED)
+	if (type == BTRFS_ORDERED_COMPRESSED)
 		extent_map_set_compression(em, compress_type);
 
 	ret = btrfs_replace_extent_map_range(inode, em, true);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 472918a5bc73..d9777649e170 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -4574,8 +4574,8 @@ static int log_extent_csums(struct btrfs_trans_handle *trans,
 	struct btrfs_root *csum_root;
 	u64 csum_offset;
 	u64 csum_len;
-	u64 mod_start = em->mod_start;
-	u64 mod_len = em->mod_len;
+	u64 mod_start = em->start;
+	u64 mod_len = em->len;
 	LIST_HEAD(ordered_sums);
 	int ret = 0;
 
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 90b0222390e5..766cfd48386c 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -277,8 +277,7 @@ DEFINE_EVENT(btrfs__inode, btrfs_inode_evict,
 		{ EXTENT_FLAG_COMPRESS_LZO,	"COMPRESS_LZO"	},\
 		{ EXTENT_FLAG_COMPRESS_ZSTD,	"COMPRESS_ZSTD"	},\
 		{ EXTENT_FLAG_PREALLOC,		"PREALLOC"	},\
-		{ EXTENT_FLAG_LOGGING,		"LOGGING"	},\
-		{ EXTENT_FLAG_FILLING,		"FILLING"	})
+		{ EXTENT_FLAG_LOGGING,		"LOGGING"	})
 
 TRACE_EVENT_CONDITION(btrfs_get_extent,