Btrfs: Let some locks go during defrag and snapshot dropping

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 42aa203..8b7d015 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -300,9 +300,9 @@
 	struct radix_tree_root block_group_data_radix;
 	struct radix_tree_root extent_map_radix;
 
-	u64 extent_tree_insert[BTRFS_MAX_LEVEL * 3];
+	u64 extent_tree_insert[BTRFS_MAX_LEVEL * 6];
 	int extent_tree_insert_nr;
-	u64 extent_tree_prealloc[BTRFS_MAX_LEVEL * 3];
+	u64 extent_tree_prealloc[BTRFS_MAX_LEVEL * 6];
 	int extent_tree_prealloc_nr;
 
 	u64 generation;