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authorMichel Lespinasse <walken@google.com>2012-10-09 03:30:37 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-09 11:22:32 +0400
commitbf7ad8eeab995710c766df49c9c69a8592ca0216 (patch)
tree737988d677b8ea408a44a58a949cc0e8eda02440
parentea5272f5c94fb2ee62f4f15a5b88eef6184cd506 (diff)
downloadlinux-bf7ad8eeab995710c766df49c9c69a8592ca0216.tar.xz
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>
-rw-r--r--fs/jffs2/readinode.c13
-rw-r--r--include/linux/rbtree.h34
-rw-r--r--lib/rbtree.c20
3 files changed, 36 insertions, 31 deletions
diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c
index 1ea349fff68b..ae81b01e6fd7 100644
--- a/fs/jffs2/readinode.c
+++ b/fs/jffs2/readinode.c
@@ -394,8 +394,11 @@ static int jffs2_add_tn_to_tree(struct jffs2_sb_info *c,
}
/* Trivial function to remove the last node in the tree. Which by definition
- has no right-hand -- so can be removed just by making its only child (if
- any) take its place under its parent. */
+ has no right-hand child — so can be removed just by making its left-hand
+ child (if any) take its place under its parent. Since this is only done
+ when we're consuming the whole tree, there's no need to use rb_erase()
+ and let it worry about adjusting colours and balancing the tree. That
+ would just be a waste of time. */
static void eat_last(struct rb_root *root, struct rb_node *node)
{
struct rb_node *parent = rb_parent(node);
@@ -412,12 +415,12 @@ static void eat_last(struct rb_root *root, struct rb_node *node)
link = &parent->rb_right;
*link = node->rb_left;
- /* Colour doesn't matter now. Only the parent pointer. */
if (node->rb_left)
- node->rb_left->rb_parent_color = node->rb_parent_color;
+ node->rb_left->__rb_parent_color = node->__rb_parent_color;
}
-/* We put this in reverse order, so we can just use eat_last */
+/* We put the version tree in reverse order, so we can use the same eat_last()
+ function that we use to consume the tmpnode tree (tn_root). */
static void ver_insert(struct rb_root *ver_root, struct jffs2_tmp_dnode_info *tn)
{
struct rb_node **link = &ver_root->rb_node;
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index 2049087c43b7..bf836a2c6a32 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -32,37 +32,19 @@
#include <linux/kernel.h>
#include <linux/stddef.h>
-struct rb_node
-{
- unsigned long rb_parent_color;
-#define RB_RED 0
-#define RB_BLACK 1
+struct rb_node {
+ unsigned long __rb_parent_color;
struct rb_node *rb_right;
struct rb_node *rb_left;
} __attribute__((aligned(sizeof(long))));
/* The alignment might seem pointless, but allegedly CRIS needs it */
-struct rb_root
-{
+struct rb_root {
struct rb_node *rb_node;
};
-#define rb_parent(r) ((struct rb_node *)((r)->rb_parent_color & ~3))
-#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->rb_parent_color & 3) | (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;
-}
+#define rb_parent(r) ((struct rb_node *)((r)->__rb_parent_color & ~3))
#define RB_ROOT (struct rb_root) { NULL, }
#define rb_entry(ptr, type, member) container_of(ptr, type, member)
@@ -70,8 +52,10 @@ static inline void rb_set_color(struct rb_node *rb, int color)
#define RB_EMPTY_ROOT(root) ((root)->rb_node == NULL)
/* 'empty' nodes are nodes that are known not to be inserted in an rbree */
-#define RB_EMPTY_NODE(node) ((node)->rb_parent_color == (unsigned long)(node))
-#define RB_CLEAR_NODE(node) ((node)->rb_parent_color = (unsigned long)(node))
+#define RB_EMPTY_NODE(node) \
+ ((node)->__rb_parent_color == (unsigned long)(node))
+#define RB_CLEAR_NODE(node) \
+ ((node)->__rb_parent_color = (unsigned long)(node))
extern void rb_insert_color(struct rb_node *, struct rb_root *);
@@ -98,7 +82,7 @@ extern void rb_replace_node(struct rb_node *victim, struct rb_node *new,
static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
struct rb_node ** rb_link)
{
- node->rb_parent_color = (unsigned long )parent;
+ node->__rb_parent_color = (unsigned long)parent;
node->rb_left = node->rb_right = NULL;
*rb_link = node;
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);