resize2fs: fix overly-pessimistic calculation of minimum size required

For extent-mapped file systems, we need to reserve some extra space in
case we need to grow the extent tree.  Calculate the safety margin
more intelligently, so we don't overestimate the amount of space
required.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Dmitry Monakhov <dmonakhov@openvz.org>
1 file changed