[PATCH] snapshot, defragment and raid test cases for btrfs

[Anand Jain]

Hi,

  Attached is the patch for the xfstests, which adds snapshot,
  defragment and volume management test cases for the btrfs
  (257, 258 and 259 respectively).

  This introduces a new user variable 'DISK_POOL' which should
  be set to disks for the raid tests.

  An example of usage of these tests is as below.
------------
[root at localhost xfstests]# cat local.config
TEST_DEV="/dev/sdd"
TEST_DIR=/btrfs
SCRATCH_DEV="/dev/sde"
SCRATCH_MNT=/btrfs1
DISK_POOL="/dev/sdf /dev/sdg"
[root at localhost xfstests]#

[root at localhost xfstests]# ./check 257 258 259
FSTYP -- btrfs
PLATFORM -- Linux/i686 localhost 3.0.0-rc6+
MKFS_OPTIONS -- /dev/sde
MOUNT_OPTIONS -- -o context=system_u:object_r:nfs_t:s0 /dev/sde /btrfs1

257 8s
258 3s
259 33s
Ran: 257 258 259
Passed all 3 tests
----------------

  Thank you.

Anand