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authorWolfram Strepp <wstrepp@gmx.de>2009-06-16 15:34:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 19:47:56 -0700
commit4c60117811171d867d4f27f17ea07d7419d45dae (patch)
tree9148532285b9276573f000b3125aee885afce411 /lib
parent16c047add3ceaf0ab882e3e094d1ec904d02312d (diff)
downloadvexpress-lsk-4c60117811171d867d4f27f17ea07d7419d45dae.tar.gz
rb_tree: make clear distinction between two different cases in rb_erase()
There are two cases when a node, having 2 childs, is erased: 'normal case': the successor is not the right-hand-child of the node to be erased 'special case': the successor is the right-hand child of the node to be erased Here some ascii-art, with following symbols (referring to the code): O: node to be deleted N: the successor of O P: parent of N C: child of N L: some other node normal case: O N / \ / \ / \ / \ L \ L \ / \ P ----> / \ P / \ / \ / / N C \ / \ \ C / \ special case: O|P N / \ / \ / \ / \ L \ L \ / \ N ----> / C \ / \ \ C / \ Notice that for the special case we don't have to reconnect C to N. Signed-off-by: Wolfram Strepp <wstrepp@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/rbtree.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c
index 0455685f6a7..4b4b29b4577 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -244,13 +244,13 @@ void rb_erase(struct rb_node *node, struct rb_root *root)
parent = rb_parent(node);
color = rb_color(node);
- if (child)
- rb_set_parent(child, parent);
if (parent == old) {
- parent->rb_right = child;
parent = node;
- } else
+ } else {
+ if (child)
+ rb_set_parent(child, parent);
parent->rb_left = child;
+ }
node->rb_parent_color = old->rb_parent_color;
node->rb_right = old->rb_right;