rbtree: move some implementation details from rbtree.h to rbtree.c

rbtree users must use the documented APIs to manipulate the tree
structure.  Low-level helpers to manipulate node colors and parenthood are
not part of that API, so move them to lib/rbtree.c

[dwmw2@infradead.org: fix jffs2 build issue due to renamed __rb_parent_color field]
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 1 deletions

diff --git a/lib/rbtree.c b/lib/rbtree.c
index fe43c8c5f527..ccada9abe6f5 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -23,6 +23,24 @@
 #include <linux/rbtree.h>
 #include <linux/export.h>
 
+#define RB_RED          0
+#define RB_BLACK        1
+
+#define rb_color(r)   ((r)->__rb_parent_color & 1)
+#define rb_is_red(r)   (!rb_color(r))
+#define rb_is_black(r) rb_color(r)
+#define rb_set_red(r)  do { (r)->__rb_parent_color &= ~1; } while (0)
+#define rb_set_black(r)  do { (r)->__rb_parent_color |= 1; } while (0)
+
+static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
+{
+        rb->__rb_parent_color = rb_color(rb) | (unsigned long)p;
+}
+static inline void rb_set_color(struct rb_node *rb, int color)
+{
+        rb->__rb_parent_color = (rb->__rb_parent_color & ~1) | color;
+}
+
 static void __rb_rotate_left(struct rb_node *node, struct rb_root *root)
 {
         struct rb_node *right = node->rb_right;
@@ -255,7 +273,7 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
                         rb_set_parent(old->rb_right, node);
                 }
 
-                node->rb_parent_color = old->rb_parent_color;
+                node->__rb_parent_color = old->__rb_parent_color;
                 node->rb_left = old->rb_left;
                 rb_set_parent(old->rb_left, node);