Closes#2929
Instead of just adding a fixed amount to the blocks used, try to
estimate the real space needed according to the filesystem structure
(bitmaps, inodes, blocks).
The side effect of this is that we no longer significantly overestimate
the size needed for small file systems.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
With the ROOTFS_TARGET conversion, EXT2_OPTS gets evaluated very early
(before TARGET_DIR is populated with files), so the calculated
blocks/inodes numbers are wrong.
Fix it by moving the calculation to a shell script wrapper around
genext2fs, so it only gets executed just before genext2fs runs.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
