gfs2: Use qd_sbd more consequently

Before this patch many of the functions in quota.c got their superblock
pointer, sdp, from the quota_data's glock pointer. That's silly because
the qd already has its own pointer to the superblock (qd_sbd).

This patch changes references to use that instead, eliminating a level
of indirection.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/quota.c

@@ -119,7 +119,7 @@ static void gfs2_qd_dispose(struct list_head *list)
 
 	while (!list_empty(list)) {
 		qd = list_first_entry(list, struct gfs2_quota_data, qd_lru);
-		sdp = qd->qd_gl->gl_name.ln_sbd;
+		sdp = qd->qd_sbd;
 
 		list_del(&qd->qd_lru);
 
@@ -302,7 +302,7 @@ static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
 
 static void qd_hold(struct gfs2_quota_data *qd)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 	gfs2_assert(sdp, !__lockref_is_dead(&qd->qd_lockref));
 	lockref_get(&qd->qd_lockref);
 }
@@ -367,7 +367,7 @@ static void slot_put(struct gfs2_quota_data *qd)
 
 static int bh_get(struct gfs2_quota_data *qd)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 	struct inode *inode = sdp->sd_qc_inode;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	unsigned int block, offset;
@@ -421,7 +421,7 @@ static int bh_get(struct gfs2_quota_data *qd)
 
 static void bh_put(struct gfs2_quota_data *qd)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 
 	mutex_lock(&sdp->sd_quota_mutex);
 	gfs2_assert(sdp, qd->qd_bh_count);
@@ -489,8 +489,7 @@ static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
 
 static void qd_unlock(struct gfs2_quota_data *qd)
 {
-	gfs2_assert_warn(qd->qd_gl->gl_name.ln_sbd,
-			 test_bit(QDF_LOCKED, &qd->qd_flags));
+	gfs2_assert_warn(qd->qd_sbd, test_bit(QDF_LOCKED, &qd->qd_flags));
 	clear_bit(QDF_LOCKED, &qd->qd_flags);
 	bh_put(qd);
 	slot_put(qd);
@@ -666,7 +665,7 @@ static int sort_qd(const void *a, const void *b)
 
 static void do_qc(struct gfs2_quota_data *qd, s64 change, int qc_type)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
 	struct gfs2_quota_change *qc = qd->qd_bh_qc;
 	s64 x;
@@ -881,7 +880,7 @@ static int gfs2_adjust_quota(struct gfs2_inode *ip, loff_t loc,
 
 static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 {
-	struct gfs2_sbd *sdp = (*qda)->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = (*qda)->qd_sbd;
 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
 	struct gfs2_alloc_parms ap = { .aflags = 0, };
 	unsigned int data_blocks, ind_blocks;
@@ -1009,11 +1008,12 @@ static int update_qd(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd)
 static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
 		    struct gfs2_holder *q_gh)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
 	struct gfs2_holder i_gh;
 	int error;
 
+	gfs2_assert_warn(sdp, sdp == qd->qd_gl->gl_name.ln_sbd);
 restart:
 	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
 	if (error)
@@ -1091,7 +1091,7 @@ int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
 
 static int need_sync(struct gfs2_quota_data *qd)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 	struct gfs2_tune *gt = &sdp->sd_tune;
 	s64 value;
 	unsigned int num, den;
@@ -1178,7 +1178,7 @@ void gfs2_quota_unlock(struct gfs2_inode *ip)
 
 static int print_message(struct gfs2_quota_data *qd, char *type)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_name.ln_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 
 	fs_info(sdp, "quota %s for %s %u\n",
 		type,