mke2fs: optionally create undo file

Provide the user with an option to create an undo file so that they
can roll back a failed tuning operation.  Previously, one would be
created if force_undo was set in the configuration file and a bunch of
(undocumented) conditions were met.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2 files changed