* @slot: pointer to slot
* @item: new item to store in the slot.
*
- * For use with radix_tree_lookup_slot() and
- * radix_tree_gang_lookup_tag_slot(). Caller must hold tree write locked
+ * For use with radix_tree_lookup_slot(). Caller must hold tree write locked
* across slot lookup and replacement.
*
* NOTE: This cannot be used to switch between non-entries (empty slots),
}
EXPORT_SYMBOL(radix_tree_gang_lookup_tag);
-/**
- * radix_tree_gang_lookup_tag_slot - perform multiple slot lookup on a
- * radix tree based on a tag
- * @root: radix tree root
- * @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 (< 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 slots at *@results and
- * returns the number of slots which were placed at *@results.
- */
-unsigned int
-radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root,
- void __rcu ***results, unsigned long first_index,
- unsigned int max_items, unsigned int tag)
-{
- struct radix_tree_iter iter;
- void __rcu **slot;
- unsigned int ret = 0;
-
- if (unlikely(!max_items))
- return 0;
-
- radix_tree_for_each_tagged(slot, root, &iter, first_index, tag) {
- results[ret] = slot;
- if (++ret == max_items)
- break;
- }
-
- return ret;
-}
-EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);
-
static bool __radix_tree_delete(struct radix_tree_root *root,
struct radix_tree_node *node, void __rcu **slot)
{
/*
* Regression2
* Description:
- * Toshiyuki Okajima describes the following radix-tree bug:
+ * Toshiyuki Okajima describes the following bug, originally found in the
+ * radix tree and now translated into XArray terminology:
*
- * In the following case, we can get a hangup on
- * radix_radix_tree_gang_lookup_tag_slot.
+ * In the following case, we can get a hang in xa_extract.
*
- * 0. The radix tree contains RADIX_TREE_MAP_SIZE items. And the tag of
- * a certain item has PAGECACHE_TAG_DIRTY.
- * 1. radix_tree_range_tag_if_tagged(, start, end, , PAGECACHE_TAG_DIRTY,
- * PAGECACHE_TAG_TOWRITE) is called to add PAGECACHE_TAG_TOWRITE tag
- * for the tag which has PAGECACHE_TAG_DIRTY. However, there is no tag with
- * PAGECACHE_TAG_DIRTY within the range from start to end. As the result,
- * There is no tag with PAGECACHE_TAG_TOWRITE but the root tag has
- * PAGECACHE_TAG_TOWRITE.
- * 2. An item is added into the radix tree and then the level of it is
- * extended into 2 from 1. At that time, the new radix tree node succeeds
- * the tag status of the root tag. Therefore the tag of the new radix tree
- * node has PAGECACHE_TAG_TOWRITE but there is not slot with
- * PAGECACHE_TAG_TOWRITE tag in the child node of the new radix tree node.
- * 3. The tag of a certain item is cleared with PAGECACHE_TAG_DIRTY.
- * 4. All items within the index range from 0 to RADIX_TREE_MAP_SIZE - 1 are
- * released. (Only the item which index is RADIX_TREE_MAP_SIZE exist in the
- * radix tree.) As the result, the slot of the radix tree node is NULL but
- * the tag which corresponds to the slot has PAGECACHE_TAG_TOWRITE.
- * 5. radix_tree_gang_lookup_tag_slot(PAGECACHE_TAG_TOWRITE) calls
- * __lookup_tag. __lookup_tag returns with 0. And __lookup_tag doesn't
- * change the index that is the input and output parameter. Because the 1st
- * slot of the radix tree node is NULL, but the tag which corresponds to
- * the slot has PAGECACHE_TAG_TOWRITE.
- * Therefore radix_tree_gang_lookup_tag_slot tries to get some items by
- * calling __lookup_tag, but it cannot get any items forever.
+ * 0. The xarray contains XA_CHUNK_SIZE items. And a certain entry is marked
+ * with PAGECACHE_TAG_DIRTY.
+ * 1. tag_tagged_items(, start, end, , PAGECACHE_TAG_DIRTY,
+ * PAGECACHE_TAG_TOWRITE) is called to set PAGECACHE_TAG_TOWRITE on
+ * entries which have PAGECACHE_TAG_DIRTY. However, there is no entry with
+ * PAGECACHE_TAG_DIRTY within the range from start to end. As a result,
+ * there is no entry with PAGECACHE_TAG_TOWRITE but the root is marked
+ * PAGECACHE_TAG_TOWRITE.
+ * 2. An item is added into the xarray and then the level of it is
+ * extended into 2 from 1. At that time, the new xa_node inherits
+ * the mark from the root. Therefore the new xa_node has
+ * PAGECACHE_TAG_TOWRITE but none of its children have that mark.
+ * 3. The PAGECACHE_TAG_DIRTY mark is cleared from the entry in step 0.
+ * 4. All entries within the index range from 0 to XA_CHUNK_SIZE - 1 are
+ * released (only the entry at index XA_CHUNK_SIZE exists in the
+ * xarray). As the result, the slot of the xa_node is NULL but
+ * the slot still has PAGECACHE_TAG_TOWRITE set.
+ * 5. xa_extract(, PAGECACHE_TAG_TOWRITE) finds slot 0 has the tag set
+ * and tries to get some items, but it spins forever.
*
- * The fix is to change that radix_tree_tag_if_tagged doesn't tag the root tag
- * if it doesn't set any tags within the specified range.
+ * The fix is to change tag_tagged_items() to not mark the root
+ * if it doesn't set any marks within the specified range.
*
* Running:
* This test should run to completion immediately. The above bug would cause it
* to hang indefinitely.
- *
- * Upstream commit:
- * Not yet
*/
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/slab.h>
-#include <linux/radix-tree.h>
+#include <linux/xarray.h>
#include <stdlib.h>
#include <stdio.h>
#define PAGECACHE_TAG_WRITEBACK XA_MARK_1
#define PAGECACHE_TAG_TOWRITE XA_MARK_2
-static RADIX_TREE(mt_tree, GFP_KERNEL);
-unsigned long page_count = 0;
+static DEFINE_XARRAY(mt_tree);
+static unsigned long page_count = 0;
struct page {
unsigned long index;
{
int i;
struct page *p;
- int max_slots = RADIX_TREE_MAP_SIZE;
+ int max_slots = XA_CHUNK_SIZE;
unsigned long int start, end;
struct page *pages[1];
/* 0. */
for (i = 0; i <= max_slots - 1; i++) {
p = page_alloc();
- radix_tree_insert(&mt_tree, i, p);
+ xa_store(&mt_tree, i, p, GFP_KERNEL);
}
- radix_tree_tag_set(&mt_tree, max_slots - 1, PAGECACHE_TAG_DIRTY);
+ xa_set_mark(&mt_tree, max_slots - 1, PAGECACHE_TAG_DIRTY);
/* 1. */
start = 0;
/* 2. */
p = page_alloc();
- radix_tree_insert(&mt_tree, max_slots, p);
+ xa_store(&mt_tree, max_slots, p, GFP_KERNEL);
/* 3. */
- radix_tree_tag_clear(&mt_tree, max_slots - 1, PAGECACHE_TAG_DIRTY);
+ xa_clear_mark(&mt_tree, max_slots - 1, PAGECACHE_TAG_DIRTY);
/* 4. */
for (i = max_slots - 1; i >= 0; i--)
- free(radix_tree_delete(&mt_tree, i));
+ free(xa_erase(&mt_tree, i));
/* 5. */
- // NOTE: start should not be 0 because radix_tree_gang_lookup_tag_slot
- // can return.
+ // NOTE: start should not be 0 because xa_extract can return.
start = 1;
end = max_slots - 2;
- radix_tree_gang_lookup_tag_slot(&mt_tree, (void ***)pages, start, end,
+ xa_extract(&mt_tree, (void **)pages, start, 1, end,
PAGECACHE_TAG_TOWRITE);
/* We remove all the remained nodes */
- free(radix_tree_delete(&mt_tree, max_slots));
+ free(xa_erase(&mt_tree, max_slots));
- BUG_ON(!radix_tree_empty(&mt_tree));
+ BUG_ON(!xa_empty(&mt_tree));
printv(1, "regression test 2, done\n");
}
projects / users / willy / xarray.git / commitdiff