diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 286ab7c27db089..53a3f5e5ae899d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7442,6 +7442,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
 	u64 block_start, orig_start, orig_block_len, ram_bytes;
 	bool can_nocow = false;
 	bool space_reserved = false;
+	u64 prev_len;
 	int ret = 0;
 
 	/*
@@ -7469,6 +7470,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
 			can_nocow = true;
 	}
 
+	prev_len = len;
 	if (can_nocow) {
 		struct extent_map *em2;
 
@@ -7498,8 +7500,6 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
 			goto out;
 		}
 	} else {
-		const u64 prev_len = len;
-
 		/* Our caller expects us to free the input extent map. */
 		free_extent_map(em);
 		*map = NULL;
@@ -7530,7 +7530,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
 	 * We have created our ordered extent, so we can now release our reservation
 	 * for an outstanding extent.
 	 */
-	btrfs_delalloc_release_extents(BTRFS_I(inode), len);
+	btrfs_delalloc_release_extents(BTRFS_I(inode), prev_len);
 
 	/*
 	 * Need to update the i_size under the extent lock so buffered