If the radix tree user attempted to insert a colliding entry with an
existing multiorder entry, then radix_tree_create() could encounter
a sibling entry when walking down the tree to look for a slot.
Use radix_tree_descend() to fix the problem, and add a test-case to make
sure the problem doesn't come back in future.
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
---
lib/radix-tree.c | 4 ++--
tools/testing/radix-tree/multiorder.c | 5 +++++
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index b1ca744..9b5d8a9 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -548,9 +548,9 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
/* Go a level down */
height--;
shift -= RADIX_TREE_MAP_SHIFT;
- offset = (index >> shift) & RADIX_TREE_MAP_MASK;
node = indirect_to_ptr(slot);
- slot = node->slots[offset];
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+ offset = radix_tree_descend(node, &slot, offset);
}
#ifdef CONFIG_RADIX_TREE_MULTIORDER
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 1b6fc9b..fc93457 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -135,6 +135,11 @@ static void multiorder_check(unsigned long index, int order)
item_check_absent(&tree, i);
for (i = max; i < 2*max; i++)
item_check_absent(&tree, i);
+ for (i = min; i < max; i++) {
+ static void *entry = (void *)
+ (0xA0 | RADIX_TREE_EXCEPTIONAL_ENTRY);
+ assert(radix_tree_insert(&tree, i, entry) == -EEXIST);
+ }
assert(item_delete(&tree, index) != 0);
--
2.8.0.rc3
--
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