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Commit 8a14f4d8 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Linus Torvalds
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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: default avatarMatthew Wilcox <willy@linux.intel.com>
Reviewed-by: default avatarRoss 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0fc9b8ca

lib/radix-tree.c

+2 −2
Original line number Diff line number Diff line
@@ -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

tools/testing/radix-tree/multiorder.c

+5 −0
Original line number Diff line number Diff line
@@ -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);