From: Steven Whitehouse <swhiteho@redhat.com>
Date: Tue, 12 Feb 2008 17:07:13 +0000
Subject: [gfs2] fix calling of drop_bh
Message-id: 1202836033.22038.446.camel@quoit
O-Subject: [RHEL 5.2] bz #423370 Fix calling of drop_bh
Bugzilla: 432370

Hi,

Here is the patch from upstream. Its been tested and shown to fix bz
#423370. This one is fairly urgent since its holding up testing,

Steve.

------------------------------------------------------------------------------------
>From c3938ce043464e99b813be64929b15da03bd7417 Mon Sep 17 00:00:00 2001
From: Steven Whitehouse <swhiteho@redhat.com>
Date: Tue, 12 Feb 2008 15:28:21 +0000
Subject: [PATCH 4/4] [GFS2] Fix bug where we called drop_bh incorrectly

As a result of an earlier patch, drop_bh was being called in cases
when it shouldn't have been. Since we never have a gh in the drop
case and we always have a gh in the promote case, we can use that
extra information to tell which case has been seen.

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

Acked-by: Bob Peterson <rpeterso@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 515b241..89110f0 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -767,7 +767,6 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
 {
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	const struct gfs2_glock_operations *glops = gl->gl_ops;
-	struct gfs2_holder *gh = gl->gl_req_gh;
 
 	gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
 	gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
@@ -778,23 +777,11 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
 	if (glops->go_inval)
 		glops->go_inval(gl, DIO_METADATA);
 
-	if (gh) {
-		spin_lock(&gl->gl_spin);
-		list_del_init(&gh->gh_list);
-		gh->gh_error = 0;
-		spin_unlock(&gl->gl_spin);
-	}
-
 	spin_lock(&gl->gl_spin);
 	gfs2_demote_wake(gl);
-	gl->gl_req_gh = NULL;
 	clear_bit(GLF_LOCK, &gl->gl_flags);
 	spin_unlock(&gl->gl_spin);
-
 	gfs2_glock_put(gl);
-
-	if (gh)
-		gfs2_holder_wake(gh);
 }
 
 /**
@@ -812,7 +799,7 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
 	int prev_state = gl->gl_state;
 	int op_done = 1;
 
-	if ((ret & LM_OUT_ST_MASK) == LM_ST_UNLOCKED) {
+	if (!gh && (ret & LM_OUT_ST_MASK) == LM_ST_UNLOCKED) {
 		drop_bh(gl, ret);
 		return;
 	}