[PATCH v1 net-next 3/6] af_unix: Manage inflight graph state as unix_graph_state.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

The graph state is managed by two variables, unix_graph_maybe_cyclic
and unix_graph_grouped.

However, unix_graph_grouped is checked only when unix_graph_maybe_cyclic
is true, so the graph state is actually tri-state.

Let's merge the two variables into unix_graph_state.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/unix/garbage.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index 7ffb80dd422c..478b2eb479a2 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -112,8 +112,13 @@ static struct unix_vertex *unix_edge_successor(struct unix_edge *edge)
 	return edge->successor->vertex;
 }
 
-static bool unix_graph_maybe_cyclic;
-static bool unix_graph_grouped;
+enum {
+	UNIX_GRAPH_NOT_CYCLIC,
+	UNIX_GRAPH_MAYBE_CYCLIC,
+	UNIX_GRAPH_CYCLIC,
+};
+
+static unsigned char unix_graph_state;
 
 static void unix_update_graph(struct unix_vertex *vertex)
 {
@@ -123,8 +128,7 @@ static void unix_update_graph(struct unix_vertex *vertex)
 	if (!vertex)
 		return;
 
-	unix_graph_maybe_cyclic = true;
-	unix_graph_grouped = false;
+	unix_graph_state = UNIX_GRAPH_MAYBE_CYCLIC;
 }
 
 static LIST_HEAD(unix_unvisited_vertices);
@@ -525,8 +529,7 @@ static void unix_walk_scc(struct sk_buff_head *hitlist)
 	list_replace_init(&unix_visited_vertices, &unix_unvisited_vertices);
 	swap(unix_vertex_unvisited_index, unix_vertex_grouped_index);
 
-	unix_graph_maybe_cyclic = !!unix_graph_circles;
-	unix_graph_grouped = true;
+	unix_graph_state = unix_graph_circles ? UNIX_GRAPH_CYCLIC : UNIX_GRAPH_NOT_CYCLIC;
 }
 
 static void unix_walk_scc_fast(struct sk_buff_head *hitlist)
@@ -557,7 +560,7 @@ static void unix_walk_scc_fast(struct sk_buff_head *hitlist)
 	list_replace_init(&unix_visited_vertices, &unix_unvisited_vertices);
 
 	if (!unix_graph_circles)
-		unix_graph_maybe_cyclic = false;
+		unix_graph_state = UNIX_GRAPH_NOT_CYCLIC;
 }
 
 static bool gc_in_progress;
@@ -569,14 +572,14 @@ static void __unix_gc(struct work_struct *work)
 
 	spin_lock(&unix_gc_lock);
 
-	if (!unix_graph_maybe_cyclic) {
+	if (unix_graph_state == UNIX_GRAPH_NOT_CYCLIC) {
 		spin_unlock(&unix_gc_lock);
 		goto skip_gc;
 	}
 
 	__skb_queue_head_init(&hitlist);
 
-	if (unix_graph_grouped)
+	if (unix_graph_state == UNIX_GRAPH_CYCLIC)
 		unix_walk_scc_fast(&hitlist);
 	else
 		unix_walk_scc(&hitlist);
-- 
2.30.2