btrfs: sink parameter is_data to btrfs_set_disk_extent_flags

The parameter has been added in 2009 in the infamous monster commit
5d4f98a2 ("Btrfs: Mixed back reference  (FORWARD ROLLING FORMAT
CHANGE)") but not used ever since. We can sink it and allow further
simplifications.
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/ctree.c

@@ -343,7 +343,7 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
 			int level = btrfs_header_level(buf);
 
 			ret = btrfs_set_disk_extent_flags(trans, buf,
-							  new_flags, level, 0);
+							  new_flags, level);
 			if (ret)
 				return ret;
 		}

fs/btrfs/ctree.h

@@ -2811,8 +2811,7 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 		  struct extent_buffer *buf, int full_backref);
 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
-				struct extent_buffer *eb, u64 flags,
-				int level, int is_data);
+				struct extent_buffer *eb, u64 flags, int level);
 int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref);
 
 int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,

fs/btrfs/extent-tree.c

@@ -2180,7 +2180,7 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 
 int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
 				struct extent_buffer *eb, u64 flags,
-				int level, int is_data)
+				int level)
 {
 	struct btrfs_delayed_extent_op *extent_op;
 	int ret;
@@ -2192,7 +2192,7 @@ 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 = is_data ? true : false;
+	extent_op->is_data = false;
 	extent_op->level = level;
 
 	ret = btrfs_add_delayed_extent_op(trans, eb->start, eb->len, extent_op);
@@ -5136,7 +5136,7 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
 		ret = btrfs_dec_ref(trans, root, eb, 0);
 		BUG_ON(ret); /* -ENOMEM */
 		ret = btrfs_set_disk_extent_flags(trans, eb, flag,
-						  btrfs_header_level(eb), 0);
+						  btrfs_header_level(eb));
 		BUG_ON(ret); /* -ENOMEM */
 		wc->flags[level] |= flag;
 	}