GFS2: Log the reason for log flushes in every log header

This patch just adds the capability for GFS2 to track which function
called gfs2_log_flush. This should make it easier to diagnose
problems based on the sequence of events found in the journals.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/trans.c

@@ -117,7 +117,8 @@ void gfs2_trans_end(struct gfs2_sbd *sdp)
 	up_read(&sdp->sd_log_flush_lock);
 
 	if (sdp->sd_vfs->s_flags & SB_SYNCHRONOUS)
-		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL);
+		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
+			       GFS2_LFC_TRANS_END);
 	if (alloced)
 		sb_end_intwrite(sdp->sd_vfs);
 }