From bf7ad8eeab995710c766df49c9c69a8592ca0216 Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Mon, 8 Oct 2012 16:30:37 -0700 Subject: [PATCH] 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 Cc: Andrea Arcangeli Acked-by: David Woodhouse Cc: Rik van Riel Cc: Peter Zijlstra Cc: Daniel Santos Cc: Jens Axboe Cc: "Eric W. Biederman" Signed-off-by: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/jffs2/readinode.c | 13 ++++++++----- include/linux/rbtree.h | 34 +++++++++------------------------- lib/rbtree.c | 20 +++++++++++++++++++- 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 #include -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 #include +#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); -- 2.30.2