e2freefrag: use GETFSMAP on mounted filesystems

Use GETFSMAP to query mounted filesystems for free space information.
This prevents us from reporting stale free space stats if there happen
to be uncheckpointed block bitmap updates sitting in the journal.

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