[PATCH] Corrections to Documentation/rbtree.txt

Ian Abbott
2008-03-20T16:00:11Z

From: Ian Abbott <abbotti@mev.co.uk>

The description of the rb_entry() macro in Documentation/rbtree.txt seems incorrect.
This patch improves it (hopefully). Also I changed the example code to call the
previous 'my_search()' example instead of an undefined 'mysearch()'.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
--- linux-2.6.24/Documentation/rbtree.txt.orig 2008-01-24 22:58:37.000000000 +0000
+++ linux-2.6.24/Documentation/rbtree.txt 2008-03-20 15:14:55.000000000 +0000
@@ -64,8 +64,8 @@
};

When dealing with a pointer to the embedded struct rb_node, the containing data
-structure may be accessed with the standard container_of() macro. In addition,
-individual members may be accessed directly via rb_entry(node, type, member).
+structure may be accessed with the rb_entry() macro, which is a synonym for the
+standard container_of() macro.

At the root of each rbtree is an rb_root structure, which is initialized to be
empty via:
@@ -85,7 +85,7 @@
struct rb_node *node = root->rb_node;

while (node) {
- struct mytype *data = container_of(node, struct mytype, node);
+ struct mytype *data = rb_entry(node, struct mytype, node);
int result;

result = strcmp(string, data->keystring);
@@ -118,7 +118,7 @@

/* Figure out where to put new node */
while (*new) {
- struct mytype *this = container_of(*new, struct mytype, node);
+ struct mytype *this = rb_entry(*new, struct mytype, node);
int result = strcmp(data->keystring, this->keystring);

parent = *new;
@@ -146,7 +146,7 @@

Example:

- struct mytype *data = mysearch(mytree, "walrus");
+ struct mytype *data = my_search(mytree, "walrus");

if (data) {
rb_erase(data->node, mytree);
@@ -180,13 +180,11 @@
NULL when there are no more nodes left.

The iterator functions return a pointer to the embedded struct rb_node, from
-which the containing data structure may be accessed with the container_of()
-macro, and individual members may be accessed directly via
-rb_entry(node, type, member).
+which the containing data structure may be accessed with the rb_entry() macro.

Example:

struct rb_node *node;
for (node = rb_first(&mytree); node; node = rb_next(node))
- printk("key=%s\n", rb_entry(node, int, keystring));
+ printk("key=%s\n", rb_entry(node, struct mytype, node)->keystring);