MDEV-17849 Undo tablespace truncation recovery fails to shrink file

fil_space_t::add(): Replaces fil_node_create(), fil_node_create_low().
Let the caller pass fil_node_t::handle, to avoid having to close and
re-open files.

fil_node_t::read_page0(): Refactored from fil_node_open_file().
Read the first page of a data file.

fil_node_open_file(): Open the file only once.

srv_undo_tablespace_open(): Set the file handle for the opened
undo tablespace. This should ensure that ut_ad(file->is_open())
no longer fails in recv_add_trim().

xtrabackup_backup_func(): Remove some dead code.

xb_fil_cur_open(): Open files only if needed. Undo tablespaces
should already have been opened.

1 files changed, 5 insertions, 8 deletions

diff --git a/storage/innobase/fsp/fsp0space.cc b/storage/innobase/fsp/fsp0space.cc
index df234f7274e..88b34be4952 100644
--- a/storage/innobase/fsp/fsp0space.cc
+++ b/storage/innobase/fsp/fsp0space.cc
@@ -123,18 +123,15 @@ Tablespace::open_or_create(bool is_temp)
 				is_temp
 				? FIL_TYPE_TEMPORARY : FIL_TYPE_TABLESPACE,
 				NULL);
+			if (!space) {
+				return DB_ERROR;
+			}
 		}
 
 		ut_a(fil_validate());
 
-		/* Create the tablespace node entry for this data file. */
-		if (!fil_node_create(
-			    it->m_filepath, it->m_size, space, false,
-			    TRUE)) {
-
-		       err = DB_ERROR;
-		       break;
-		}
+		space->add(it->m_filepath, OS_FILE_CLOSED, it->m_size,
+			   false, true);
 	}
 
 	return(err);