GFS2: make sure rgrps are up to date in func gfs2_blk2rgrpd

This patch adds a call to gfs2_rindex_update from function gfs2_blk2rgrpd
and removes calls to it that are made redundant by it. The problem is
that a gfs2_grow can add rgrps to the rindex, then put those rgrps into
use, thus rendering the rindex we read in at mount time incomplete.

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

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 6ff9f17..19bde40 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -332,6 +332,9 @@
 	struct rb_node *n, *next;
 	struct gfs2_rgrpd *cur;
 
+	if (gfs2_rindex_update(sdp))
+		return NULL;
+
 	spin_lock(&sdp->sd_rindex_spin);
 	n = sdp->sd_rindex_tree.rb_node;
 	while (n) {
@@ -917,10 +920,6 @@
 	if (!blk_queue_discard(q))
 		return -EOPNOTSUPP;
 
-	ret = gfs2_rindex_update(sdp);
-	if (ret)
-		return ret;
-
 	if (argp == NULL) {
 		r.start = 0;
 		r.len = ULLONG_MAX;
@@ -1671,13 +1670,8 @@
 {
 	struct gfs2_rgrpd *rgd;
 	struct gfs2_holder rgd_gh;
-	int error;
+	int error = -EINVAL;
 
-	error = gfs2_rindex_update(sdp);
-	if (error)
-		return error;
-
-	error = -EINVAL;
 	rgd = gfs2_blk2rgrpd(sdp, no_addr, 1);
 	if (!rgd)
 		goto fail;