btrfs: remove btrfs_delayed_extent_op::is_data

The value of btrfs_delayed_extent_op::is_data is always false, we can
cascade the change and simplify code that depends on it, removing the
structure member eventually.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/delayed-ref.c

@@ -930,7 +930,6 @@ int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
 	is_system = (generic_ref->tree_ref.owning_root == BTRFS_CHUNK_TREE_OBJECTID);
 
 	ASSERT(generic_ref->type == BTRFS_REF_METADATA && generic_ref->action);
-	BUG_ON(extent_op && extent_op->is_data);
 	ref = kmem_cache_alloc(btrfs_delayed_tree_ref_cachep, GFP_NOFS);
 	if (!ref)
 		return -ENOMEM;
@@ -1103,8 +1102,7 @@ int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
 		return -ENOMEM;
 
 	init_delayed_ref_head(head_ref, NULL, bytenr, num_bytes, 0, 0,
-			      BTRFS_UPDATE_DELAYED_HEAD, extent_op->is_data,
-			      false);
+			      BTRFS_UPDATE_DELAYED_HEAD, false, false);
 	head_ref->extent_op = extent_op;
 
 	delayed_refs = &trans->transaction->delayed_refs;

fs/btrfs/delayed-ref.h

@@ -58,7 +58,6 @@ struct btrfs_delayed_extent_op {
 	u8 level;
 	bool update_key;
 	bool update_flags;
-	bool is_data;
 	u64 flags_to_set;
 };
 

fs/btrfs/extent-tree.c

@@ -1577,12 +1577,12 @@ static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
 	u32 item_size;
 	int ret;
 	int err = 0;
-	int metadata = !extent_op->is_data;
+	int metadata = 1;
 
 	if (TRANS_ABORTED(trans))
 		return 0;
 
-	if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA))
+	if (!btrfs_fs_incompat(fs_info, SKINNY_METADATA))
 		metadata = 0;
 
 	path = btrfs_alloc_path();
@@ -2192,7 +2192,6 @@ int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
 	extent_op->flags_to_set = flags;
 	extent_op->update_flags = true;
 	extent_op->update_key = false;
-	extent_op->is_data = false;
 	extent_op->level = level;
 
 	ret = btrfs_add_delayed_extent_op(trans, eb->start, eb->len, extent_op);
@@ -4951,7 +4950,6 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 		extent_op->flags_to_set = flags;
 		extent_op->update_key = skinny_metadata ? false : true;
 		extent_op->update_flags = true;
-		extent_op->is_data = false;
 		extent_op->level = level;
 
 		btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT,