ext4 needs to convert allocated (metadata) blocks back into blocks
reserved for delayed allocation. Add functions into quota code for
supporting such operation.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

(cherry picked from commit 1c8924eb)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>