diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 1c36e437b027..8e1589dd1c70 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1046,6 +1046,13 @@ static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start,
 	return em;
 }
 
+static u32 get_extent_max_capacity(const struct extent_map *em)
+{
+	if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
+		return BTRFS_MAX_COMPRESSED;
+	return BTRFS_MAX_EXTENT_SIZE;
+}
+
 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em,
 				     bool locked)
 {
@@ -1062,6 +1069,12 @@ static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em,
 		goto out;
 	if (test_bit(EXTENT_FLAG_PREALLOC, &next->flags))
 		goto out;
+	/*
+	 * If the next extent is at its max capacity, defragging current extent
+	 * makes no sense, as the total number of extents won't change.
+	 */
+	if (next->len >= get_extent_max_capacity(em))
+		goto out;
 	/* Physically adjacent and large enough */
 	if ((em->block_start + em->block_len == next->block_start) &&
 	    (em->block_len > SZ_128K && next->block_len > SZ_128K))
@@ -1262,6 +1275,13 @@ static int defrag_collect_targets(struct btrfs_inode *inode,
 		if (range_len >= extent_thresh)
 			goto next;
 
+		/*
+		 * Skip extents already at its max capacity, this is mostly for
+		 * compressed extents, which max cap is only 128K.
+		 */
+		if (em->len >= get_extent_max_capacity(em))
+			goto next;
+
 		next_mergeable = defrag_check_next_extent(&inode->vfs_inode, em,
 							  locked);
 		if (!next_mergeable) {