[GFS2] don't try to lockfs after shutdown

If an fs has already been shut down, a lockfs callback should do nothing.
An fs that's been shut down can't acquire locks or do anything with
respect to the cluster.

Also, remove FIXME comment in withdraw function.  The missing bits of the
withdraw procedure are now all done by user space.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/lm.c b/fs/gfs2/lm.c
index effe4a3..e30673d 100644
--- a/fs/gfs2/lm.c
+++ b/fs/gfs2/lm.c
@@ -104,15 +104,9 @@
 	vprintk(fmt, args);
 	va_end(args);
 
-	fs_err(sdp, "about to withdraw from the cluster\n");
+	fs_err(sdp, "about to withdraw this file system\n");
 	BUG_ON(sdp->sd_args.ar_debug);
 
-
-	fs_err(sdp, "waiting for outstanding I/O\n");
-
-	/* FIXME: suspend dm device so oustanding bio's complete
-	   and all further io requests fail */
-
 	fs_err(sdp, "telling LM to withdraw\n");
 	gfs2_withdraw_lockproto(&sdp->sd_lockstruct);
 	fs_err(sdp, "withdrawn\n");
diff --git a/fs/gfs2/ops_super.c b/fs/gfs2/ops_super.c
index 7685b46..b283783 100644
--- a/fs/gfs2/ops_super.c
+++ b/fs/gfs2/ops_super.c
@@ -173,6 +173,9 @@
 	struct gfs2_sbd *sdp = sb->s_fs_info;
 	int error;
 
+	if (test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
+		return;
+
 	for (;;) {
 		error = gfs2_freeze_fs(sdp);
 		if (!error)