resize2fs: rewrite extent/dir/ea block checksums when migrating

resize2fs: rewrite extent/dir/ea block checksums when migrating

With the advent of metadata_csum, we now tie extent and directory
blocks to the associated inode number (and generation).  Therefore, we
must be careful when remapping inodes.  At that point in the resize
process, all the blocks that are going away have been duplicated
elsewhere in the FS (albeit with checksums based on the old inode
numbers).  If we're moving the inode, then do that and remember that
new inode number.  Now we can update the block mappings for each inode
with the final inode number, and schedule directory blocks for mass
inode relocation.  We also have to recalculate the EA block checksum.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>