[PATCH 0/4] ext4: ioc_move_ext fixes

Currenty EXT4_IOC_MOVE_EXT is very dangerous call because anyone who
has write perm is able to call it and trigger kernel panic. Even more
all kernel since v2.6.30-6558-g748de67 are affected, so current
Debian and Redhat server solutions are dangerous.

Tests are available here:
http://www.spinics.net/lists/linux-fsdevel/msg58316.html
Or here:
https://github.com/dmonakhov/xfstests/tree/ce8e3adab629b2a9be8ba2e73db7dad49eb46614
288'th test

This patchset attempt to close all known bugs, so it survived after
all tests i know.

TOC:
ext4: move_extent code cleanup
ext4: online defrag is not supported for journaled files
ext4: basic bug shield for move_extent_per_page V2
ext4: reimplement uninit extent optimization for move_extent_per_page V2