radix-tree: fix radix_tree_create for sibling entries
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@linux.intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 @@
/* 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