e2fsck: add support for expanding the inode size

e2fsck: add support for expanding the inode size

This patch adds a "-E expand_extra_isize" feature which makes sure
that _every_ used inode has i_extra_isize >= s_min_extra_isize if
s_min_extra_isize is set. Else it makes sure that i_extra_isize
of every inode is equal to sizeof(ext2_inode_large) - 128.

This is useful for the case where nanosecond timestamps or 64-bit
inode version fields are required for all inodes in the filesystem.

Signed-off-by: Kalpak Shah <kalpak@clusterfs.com>
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>