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-rw-r--r--lib/radix-tree.c41
1 files changed, 20 insertions, 21 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 92cdd9936e3..05da38bcc29 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -28,7 +28,6 @@
#include <linux/slab.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
-#include <linux/gfp.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/rcupdate.h>
@@ -364,7 +363,7 @@ static void *radix_tree_lookup_element(struct radix_tree_root *root,
unsigned int height, shift;
struct radix_tree_node *node, **slot;
- node = rcu_dereference(root->rnode);
+ node = rcu_dereference_raw(root->rnode);
if (node == NULL)
return NULL;
@@ -384,7 +383,7 @@ static void *radix_tree_lookup_element(struct radix_tree_root *root,
do {
slot = (struct radix_tree_node **)
(node->slots + ((index>>shift) & RADIX_TREE_MAP_MASK));
- node = rcu_dereference(*slot);
+ node = rcu_dereference_raw(*slot);
if (node == NULL)
return NULL;
@@ -556,6 +555,10 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
*
* 0: tag not present or not set
* 1: tag set
+ *
+ * Note that the return value of this function may not be relied on, even if
+ * the RCU lock is held, unless tag modification and node deletion are excluded
+ * from concurrency.
*/
int radix_tree_tag_get(struct radix_tree_root *root,
unsigned long index, unsigned int tag)
@@ -568,7 +571,7 @@ int radix_tree_tag_get(struct radix_tree_root *root,
if (!root_tag_get(root, tag))
return 0;
- node = rcu_dereference(root->rnode);
+ node = rcu_dereference_raw(root->rnode);
if (node == NULL)
return 0;
@@ -596,13 +599,9 @@ int radix_tree_tag_get(struct radix_tree_root *root,
*/
if (!tag_get(node, tag, offset))
saw_unset_tag = 1;
- if (height == 1) {
- int ret = tag_get(node, tag, offset);
-
- BUG_ON(ret && saw_unset_tag);
- return !!ret;
- }
- node = rcu_dereference(node->slots[offset]);
+ if (height == 1)
+ return !!tag_get(node, tag, offset);
+ node = rcu_dereference_raw(node->slots[offset]);
shift -= RADIX_TREE_MAP_SHIFT;
height--;
}
@@ -657,7 +656,7 @@ EXPORT_SYMBOL(radix_tree_next_hole);
*
* Returns: the index of the hole if found, otherwise returns an index
* outside of the set specified (in which case 'index - return >= max_scan'
- * will be true). In rare cases of wrap-around, LONG_MAX will be returned.
+ * will be true). In rare cases of wrap-around, ULONG_MAX will be returned.
*
* radix_tree_next_hole may be called under rcu_read_lock. However, like
* radix_tree_gang_lookup, this will not atomically search a snapshot of
@@ -675,7 +674,7 @@ unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
if (!radix_tree_lookup(root, index))
break;
index--;
- if (index == LONG_MAX)
+ if (index == ULONG_MAX)
break;
}
@@ -711,7 +710,7 @@ __lookup(struct radix_tree_node *slot, void ***results, unsigned long index,
}
shift -= RADIX_TREE_MAP_SHIFT;
- slot = rcu_dereference(slot->slots[i]);
+ slot = rcu_dereference_raw(slot->slots[i]);
if (slot == NULL)
goto out;
}
@@ -758,7 +757,7 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
unsigned long cur_index = first_index;
unsigned int ret;
- node = rcu_dereference(root->rnode);
+ node = rcu_dereference_raw(root->rnode);
if (!node)
return 0;
@@ -787,7 +786,7 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
slot = *(((void ***)results)[ret + i]);
if (!slot)
continue;
- results[ret + nr_found] = rcu_dereference(slot);
+ results[ret + nr_found] = rcu_dereference_raw(slot);
nr_found++;
}
ret += nr_found;
@@ -826,7 +825,7 @@ radix_tree_gang_lookup_slot(struct radix_tree_root *root, void ***results,
unsigned long cur_index = first_index;
unsigned int ret;
- node = rcu_dereference(root->rnode);
+ node = rcu_dereference_raw(root->rnode);
if (!node)
return 0;
@@ -915,7 +914,7 @@ __lookup_tag(struct radix_tree_node *slot, void ***results, unsigned long index,
}
}
shift -= RADIX_TREE_MAP_SHIFT;
- slot = rcu_dereference(slot->slots[i]);
+ slot = rcu_dereference_raw(slot->slots[i]);
if (slot == NULL)
break;
}
@@ -951,7 +950,7 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
if (!root_tag_get(root, tag))
return 0;
- node = rcu_dereference(root->rnode);
+ node = rcu_dereference_raw(root->rnode);
if (!node)
return 0;
@@ -980,7 +979,7 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
slot = *(((void ***)results)[ret + i]);
if (!slot)
continue;
- results[ret + nr_found] = rcu_dereference(slot);
+ results[ret + nr_found] = rcu_dereference_raw(slot);
nr_found++;
}
ret += nr_found;
@@ -1020,7 +1019,7 @@ radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
if (!root_tag_get(root, tag))
return 0;
- node = rcu_dereference(root->rnode);
+ node = rcu_dereference_raw(root->rnode);
if (!node)
return 0;