[Cluster-devel] [PATCH] [GFS2] Clean up arguments to rq_mutex/rq_promote

[Steven Whitehouse <swhiteho@redhat.com>]

By making the arguments to rq_mutex and rq_promote into glocks
and moving the asserts to those functions, run_queue becomes
much simpler. Also rq_mutex always returned 1, so I've changed it
to return void and it always breaks out of the loop.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index e4bc8ae..65d6eba 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -455,18 +455,18 @@ static void wait_on_demote(struct gfs2_glock *gl)
  * Returns: 1 if the queue is blocked
  */
 
-static int rq_mutex(struct gfs2_holder *gh)
+static void rq_mutex(struct gfs2_glock *gl)
 {
-	struct gfs2_glock *gl = gh->gh_gl;
+	struct gfs2_holder *gh = list_entry(gl->gl_waiters1.next,
+					    struct gfs2_holder, gh_list);
 
+	BUG_ON(test_bit(HIF_MUTEX, &gh->gh_iflags) == 0);
 	list_del_init(&gh->gh_list);
 	/*  gh->gh_error never examined.  */
 	set_bit(GLF_LOCK, &gl->gl_flags);
 	clear_bit(HIF_WAIT, &gh->gh_iflags);
 	smp_mb();
 	wake_up_bit(&gh->gh_iflags, HIF_WAIT);
-
-	return 1;
 }
 
 /**
@@ -478,11 +478,13 @@ static int rq_mutex(struct gfs2_holder *gh)
  * Returns: 1 if the queue is blocked
  */
 
-static int rq_promote(struct gfs2_holder *gh)
+static int rq_promote(struct gfs2_glock *gl)
 {
-	struct gfs2_glock *gl = gh->gh_gl;
+	struct gfs2_holder *gh = list_entry(gl->gl_waiters3.next,
+					    struct gfs2_holder, gh_list);
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 
+	BUG_ON(test_bit(HIF_PROMOTE, &gh->gh_iflags) == 0);
 	if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
 		if (list_empty(&gl->gl_holders)) {
 			gl->gl_req_gh = gh;
@@ -562,35 +564,21 @@ static int rq_demote(struct gfs2_glock *gl)
  */
 static void run_queue(struct gfs2_glock *gl)
 {
-	struct gfs2_holder *gh;
-	int blocked = 1;
+	int blocked;
 
 	for (;;) {
+		blocked = 1;
 		if (test_bit(GLF_LOCK, &gl->gl_flags))
 			break;
 
 		if (!list_empty(&gl->gl_waiters1)) {
-			gh = list_entry(gl->gl_waiters1.next,
-					struct gfs2_holder, gh_list);
-
-			if (test_bit(HIF_MUTEX, &gh->gh_iflags))
-				blocked = rq_mutex(gh);
-			else
-				gfs2_assert_warn(gl->gl_sbd, 0);
-
+			rq_mutex(gl);
+			break;
 		} else if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
 			blocked = rq_demote(gl);
 		} else if (!list_empty(&gl->gl_waiters3)) {
-			gh = list_entry(gl->gl_waiters3.next,
-					struct gfs2_holder, gh_list);
-
-			if (test_bit(HIF_PROMOTE, &gh->gh_iflags))
-				blocked = rq_promote(gh);
-			else
-				gfs2_assert_warn(gl->gl_sbd, 0);
-
-		} else
-			break;
+			blocked = rq_promote(gl);
+		}
 
 		if (blocked)
 			break;
-- 
1.5.1.2