aboutsummaryrefslogtreecommitdiffstats
path: root/lib/radix-tree.c
diff options
context:
space:
mode:
authorJonathan Corbet <corbet@lwn.net>2006-03-25 03:08:05 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-25 08:22:59 -0800
commitdaff89f324755f87a060d5125a205c0755811ea9 (patch)
tree5b2734bd46c8d73a068b571ba1059e67df014825 /lib/radix-tree.c
parent57070d012cd425c3a71663528c56a436abd2d9da (diff)
[PATCH] radix-tree documentation cleanups
Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'lib/radix-tree.c')
-rw-r--r--lib/radix-tree.c49
1 files changed, 27 insertions, 22 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 1e5b17dc7e3d..7097bb239e40 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -37,7 +37,6 @@
#else
#define RADIX_TREE_MAP_SHIFT 3 /* For more stressful testing */
#endif
-#define RADIX_TREE_TAGS 2
#define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT)
#define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1)
@@ -48,7 +47,7 @@
struct radix_tree_node {
unsigned int count;
void *slots[RADIX_TREE_MAP_SIZE];
- unsigned long tags[RADIX_TREE_TAGS][RADIX_TREE_TAG_LONGS];
+ unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
};
struct radix_tree_path {
@@ -135,17 +134,20 @@ out:
return ret;
}
-static inline void tag_set(struct radix_tree_node *node, int tag, int offset)
+static inline void tag_set(struct radix_tree_node *node, unsigned int tag,
+ int offset)
{
__set_bit(offset, node->tags[tag]);
}
-static inline void tag_clear(struct radix_tree_node *node, int tag, int offset)
+static inline void tag_clear(struct radix_tree_node *node, unsigned int tag,
+ int offset)
{
__clear_bit(offset, node->tags[tag]);
}
-static inline int tag_get(struct radix_tree_node *node, int tag, int offset)
+static inline int tag_get(struct radix_tree_node *node, unsigned int tag,
+ int offset)
{
return test_bit(offset, node->tags[tag]);
}
@@ -154,7 +156,7 @@ static inline int tag_get(struct radix_tree_node *node, int tag, int offset)
* Returns 1 if any slot in the node has this tag set.
* Otherwise returns 0.
*/
-static inline int any_tag_set(struct radix_tree_node *node, int tag)
+static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag)
{
int idx;
for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
@@ -180,7 +182,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
{
struct radix_tree_node *node;
unsigned int height;
- char tags[RADIX_TREE_TAGS];
+ char tags[RADIX_TREE_MAX_TAGS];
int tag;
/* Figure out what the height should be. */
@@ -197,7 +199,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
* Prepare the tag status of the top-level node for propagation
* into the newly-pushed top-level node(s)
*/
- for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
tags[tag] = 0;
if (any_tag_set(root->rnode, tag))
tags[tag] = 1;
@@ -211,7 +213,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
node->slots[0] = root->rnode;
/* Propagate the aggregated tag info into the new root */
- for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
if (tags[tag])
tag_set(node, tag, 0);
}
@@ -349,14 +351,15 @@ EXPORT_SYMBOL(radix_tree_lookup);
* @index: index key
* @tag: tag index
*
- * Set the search tag corresponging to @index in the radix tree. From
+ * Set the search tag (which must be < RADIX_TREE_MAX_TAGS)
+ * corresponding to @index in the radix tree. From
* the root all the way down to the leaf node.
*
* Returns the address of the tagged item. Setting a tag on a not-present
* item is a bug.
*/
void *radix_tree_tag_set(struct radix_tree_root *root,
- unsigned long index, int tag)
+ unsigned long index, unsigned int tag)
{
unsigned int height, shift;
struct radix_tree_node *slot;
@@ -390,7 +393,8 @@ EXPORT_SYMBOL(radix_tree_tag_set);
* @index: index key
* @tag: tag index
*
- * Clear the search tag corresponging to @index in the radix tree. If
+ * Clear the search tag (which must be < RADIX_TREE_MAX_TAGS)
+ * corresponding to @index in the radix tree. If
* this causes the leaf node to have no tags set then clear the tag in the
* next-to-leaf node, etc.
*
@@ -398,7 +402,7 @@ EXPORT_SYMBOL(radix_tree_tag_set);
* has the same return value and semantics as radix_tree_lookup().
*/
void *radix_tree_tag_clear(struct radix_tree_root *root,
- unsigned long index, int tag)
+ unsigned long index, unsigned int tag)
{
struct radix_tree_path path[RADIX_TREE_MAX_PATH], *pathp = path;
struct radix_tree_node *slot;
@@ -450,7 +454,7 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
* radix_tree_tag_get - get a tag on a radix tree node
* @root: radix tree root
* @index: index key
- * @tag: tag index
+ * @tag: tag index (< RADIX_TREE_MAX_TAGS)
*
* Return values:
*
@@ -459,7 +463,7 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
* -1: tag present, unset
*/
int radix_tree_tag_get(struct radix_tree_root *root,
- unsigned long index, int tag)
+ unsigned long index, unsigned int tag)
{
unsigned int height, shift;
struct radix_tree_node *slot;
@@ -592,7 +596,7 @@ EXPORT_SYMBOL(radix_tree_gang_lookup);
*/
static unsigned int
__lookup_tag(struct radix_tree_root *root, void **results, unsigned long index,
- unsigned int max_items, unsigned long *next_index, int tag)
+ unsigned int max_items, unsigned long *next_index, unsigned int tag)
{
unsigned int nr_found = 0;
unsigned int shift;
@@ -646,7 +650,7 @@ out:
* @results: where the results of the lookup are placed
* @first_index: start the lookup from this key
* @max_items: place up to this many items at *results
- * @tag: the tag index
+ * @tag: the tag index (< RADIX_TREE_MAX_TAGS)
*
* Performs an index-ascending scan of the tree for present items which
* have the tag indexed by @tag set. Places the items at *@results and
@@ -654,7 +658,8 @@ out:
*/
unsigned int
radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
- unsigned long first_index, unsigned int max_items, int tag)
+ unsigned long first_index, unsigned int max_items,
+ unsigned int tag)
{
const unsigned long max_index = radix_tree_maxindex(root->height);
unsigned long cur_index = first_index;
@@ -716,7 +721,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
struct radix_tree_node *slot;
unsigned int height, shift;
void *ret = NULL;
- char tags[RADIX_TREE_TAGS];
+ char tags[RADIX_TREE_MAX_TAGS];
int nr_cleared_tags;
int tag;
int offset;
@@ -751,7 +756,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
* Clear all tags associated with the just-deleted item
*/
nr_cleared_tags = 0;
- for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
tags[tag] = 1;
if (tag_get(pathp->node, tag, pathp->offset)) {
tag_clear(pathp->node, tag, pathp->offset);
@@ -763,7 +768,7 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
}
for (pathp--; nr_cleared_tags && pathp->node; pathp--) {
- for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
if (tags[tag])
continue;
@@ -801,7 +806,7 @@ EXPORT_SYMBOL(radix_tree_delete);
* @root: radix tree root
* @tag: tag to test
*/
-int radix_tree_tagged(struct radix_tree_root *root, int tag)
+int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag)
{
struct radix_tree_node *rnode;
rnode = root->rnode;

Privacy Policy