This reserved space isn't committed yet but cannot be used for allocations.
For userspace it has no difference from used space. XFS already does this.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Fixes: 689c958c ("ext4: add project quota support")