[GFS2] Eliminate the no longer needed sd_statfs_mutex

This patch eliminates the unneeded sd_statfs_mutex mutex but preserves
the ordering as discussed.

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

fs/gfs2/incore.h

@@ -529,7 +529,6 @@ struct gfs2_sbd {
 	/* StatFS stuff */
 
 	spinlock_t sd_statfs_spin;
-	struct mutex sd_statfs_mutex;
 	struct gfs2_statfs_change_host sd_statfs_master;
 	struct gfs2_statfs_change_host sd_statfs_local;
 	unsigned long sd_statfs_sync_time;

fs/gfs2/ops_fstype.c

@@ -60,7 +60,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 
 	mutex_init(&sdp->sd_inum_mutex);
 	spin_lock_init(&sdp->sd_statfs_spin);
-	mutex_init(&sdp->sd_statfs_mutex);
 
 	spin_lock_init(&sdp->sd_rindex_spin);
 	mutex_init(&sdp->sd_rindex_mutex);

fs/gfs2/super.c

@@ -688,9 +688,7 @@ void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
 	if (error)
 		return;
 
-	mutex_lock(&sdp->sd_statfs_mutex);
 	gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
-	mutex_unlock(&sdp->sd_statfs_mutex);
 
 	spin_lock(&sdp->sd_statfs_spin);
 	l_sc->sc_total += total;
@@ -738,9 +736,7 @@ int gfs2_statfs_sync(struct gfs2_sbd *sdp)
 	if (error)
 		goto out_bh2;
 
-	mutex_lock(&sdp->sd_statfs_mutex);
 	gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
-	mutex_unlock(&sdp->sd_statfs_mutex);
 
 	spin_lock(&sdp->sd_statfs_spin);
 	m_sc->sc_total += l_sc->sc_total;