GFS2: Move glock superblock pointer to field gl_name

What uniquely identifies a glock in the glock hash table is not
gl_name, but gl_name and its superblock pointer. This patch makes
the gl_name field correspond to a unique glock identifier. That will
allow us to simplify hashing with a future patch, since the hash
algorithm can then take the gl_name and hash its components in one
operation.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 2c1ae86..7833394 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -70,7 +70,7 @@
 static void maybe_release_space(struct gfs2_bufdata *bd)
 {
 	struct gfs2_glock *gl = bd->bd_gl;
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	struct gfs2_rgrpd *rgd = gl->gl_object;
 	unsigned int index = bd->bd_bh->b_blocknr - gl->gl_name.ln_number;
 	struct gfs2_bitmap *bi = rgd->rd_bits + index;
@@ -585,7 +585,7 @@
 static void gfs2_meta_sync(struct gfs2_glock *gl)
 {
 	struct address_space *mapping = gfs2_glock2aspace(gl);
-	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
 	int error;
 
 	if (mapping == NULL)
@@ -595,7 +595,7 @@
 	error = filemap_fdatawait(mapping);
 
 	if (error)
-		gfs2_io_error(gl->gl_sbd);
+		gfs2_io_error(gl->gl_name.ln_sbd);
 }
 
 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)