GFS2: decouple quota allocations from block allocations

This patch separates the code pertaining to allocations into two
parts: quota-related information and block reservations.
This patch also moves all the block reservation structure allocations to
function gfs2_inplace_reserve to simplify the code, and moves
the frees to function gfs2_inplace_release.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index 8a139ff..c150298 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -40,7 +40,8 @@
 	inode_init_once(&ip->i_inode);
 	init_rwsem(&ip->i_rw_mutex);
 	INIT_LIST_HEAD(&ip->i_trunc_list);
-	ip->i_alloc = NULL;
+	ip->i_qadata = NULL;
+	ip->i_res = NULL;
 	ip->i_hash_cache = NULL;
 }