[RBTREE] Change rbtree off-tree marking in I/O schedulers.
They were abusing the rb_color field to mark nodes which weren't currently
on the tree. Fix that to use the same method as eventpoll did -- setting
the parent pointer to point back to itself. And use the appropriate
accessor macros for setting and reading the parent.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 2540dfa..01c416b 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -60,14 +60,9 @@
/*
* rb-tree defines
*/
-#define RB_NONE (2)
#define RB_EMPTY(node) ((node)->rb_node == NULL)
-#define RB_CLEAR_COLOR(node) (node)->rb_color = RB_NONE
#define RB_CLEAR(node) do { \
- (node)->rb_parent = NULL; \
- RB_CLEAR_COLOR((node)); \
- (node)->rb_right = NULL; \
- (node)->rb_left = NULL; \
+ memset(node, 0, sizeof(*node)); \
} while (0)
#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL)
#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node)
@@ -563,7 +558,6 @@
cfq_update_next_crq(crq);
rb_erase(&crq->rb_node, &cfqq->sort_list);
- RB_CLEAR_COLOR(&crq->rb_node);
if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
cfq_del_cfqq_rr(cfqd, cfqq);