[patch 0/3] xfstests: for btrfs publishing/export patchset (v4)

[Jeff Mahoney <jeffm@suse.com>]

These are the tests that Josef requested accompany the submission of
the btrfs publishing/export patchset[1].

021: Test new global metadata reservation ioctl
022: Test new sysfs exporting of allocation and device membership
023: Test new sysfs exporting of feature bits
024: Test setting/clearing feature bits via ioctl
025: Test setting/clearing feature bits via sysfs

As part of the ioctl testing, I added a helper that can be extended
easily to export simple information via ioctl. This means that the
tests can be independent of btrfsprogs version or its output formatting.

V2:
- Used next numbers in sequence
- Better commit messages
- Fixed handling of the missing feature cases
- Fixed issues raised in Josef's review

V3:
- Fixed missing output in btrfs/023 when the ioctls arent't supported
- Fixed missing umount introduced in V2

V4:
- I was running the tests directly, not through check and didn't catch these:
 - Fixed incorrect output from 022 while running under check
 - Added tests to group file

-Jeff

[1] http://thread.gmane.org/gmane.comp.file-systems.btrfs/29307