GFS2: Remove old, unused linked list code from quota

This is the kernel portion of the patch-set for upstream gfs2,
to remove the quota-linked-list stuff and replace it with
fiemap-based traversal of the quota file.

The corresponding userland fixes have been pushed to
STABLE3 and master branches of cluster.git and gfs2-utils.git
respectively (Refer Red Hat bug #536902).

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

include/linux/gfs2_ondisk.h

@@ -179,33 +179,6 @@ struct gfs2_rgrp {
 	__u8 rg_reserved[80]; /* Several fields from gfs1 now reserved */
 };
 
-/*
- * quota linked list: user quotas and group quotas form two separate 
- * singly linked lists. ll_next stores uids or gids of next quotas in the 
- * linked list.
-
-Given the uid/gid, how to calculate the quota file offsets for the corresponding
-gfs2_quota structures on disk:
-
-for user quotas, given uid,
-offset = uid * sizeof(struct gfs2_quota);
-
-for group quotas, given gid,
-offset = (gid * sizeof(struct gfs2_quota)) + sizeof(struct gfs2_quota);
-
-
-  uid:0   gid:0       uid:12   gid:12      uid:17   gid:17     uid:5142 gid:5142
-+-------+-------+    +-------+-------+    +-------+- - - -+    +- - - -+-------+
-| valid | valid | :: | valid | valid | :: | valid | inval | :: | inval | valid |
-+-------+-------+    +-------+-------+    +-------+- - - -+    +- - - -+-------+
-next:12   next:12    next:17 next:5142    next:NULL                    next:NULL
-    |       |            |       |            |<-- user quota list         |
-     \______|___________/ \______|___________/         group quota list -->|
-            |                    |                                         |
-             \__________________/ \_______________________________________/
-
-*/
-
 /*
  * quota structure
  */
@@ -214,8 +187,7 @@ struct gfs2_quota {
 	__be64 qu_limit;
 	__be64 qu_warn;
 	__be64 qu_value;
-	__be32 qu_ll_next; /* location of next quota in list */
-	__u8 qu_reserved[60];
+	__u8 qu_reserved[64];
 };
 
 /*