tree 7208d1c89aa625fa6eb349fdafa2e49a00bbe078
parent e9662f701c85ebc99f532bf8bb53208c0648846a
author Miao Xie <miaox@cn.fujitsu.com> 1362045873 +0000
committer Josef Bacik <jbacik@fusionio.com> 1362076434 -0500

Btrfs: fix wrong reserved space in qgroup during snap/subv creation

There are two problems in the space reservation of the snapshot/
subvolume creation.
- don't reserve the space for the root item insertion
- the space which is reserved in the qgroup is different with
  the free space reservation. we need reserve free space for
  7 items, but in qgroup reservation, we need reserve space only
  for 3 items.

So we implement new metadata reservation functions for the
snapshot/subvolume creation.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>