[GFS2] Don't add glocks to the journal

The only reason for adding glocks to the journal was to keep track
of which locks required a log flush prior to release. We add a
flag to the glock to allow this check to be made in a simpler way.

This reduces the size of a glock (by 12 bytes on i386, 24 on x86_64)
and means that we can avoid extra work during the journal flush.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/log.h b/fs/gfs2/log.h
index 24e7161..4babd43 100644
--- a/fs/gfs2/log.h
+++ b/fs/gfs2/log.h
@@ -57,7 +57,14 @@
 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp);
 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 				      struct buffer_head *real);
-void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl);
+void __gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl);
+
+static inline void gfs2_log_flush(struct gfs2_sbd *sbd, struct gfs2_glock *gl)
+{
+	if (!gl || test_bit(GLF_LFLUSH, &gl->gl_flags))
+		__gfs2_log_flush(sbd, gl);
+}
+
 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *trans);
 void gfs2_remove_from_ail(struct gfs2_bufdata *bd);