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authorMatthew Wilcox <willy@linux.intel.com>2016-05-20 17:02:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-20 17:58:30 -0700
commit8a14f4d8328cc8615f8a5487c4173f36a8314796 (patch)
treedf71c04e61341c3d21acc8e2786af46759aad703 /lib
parent0fc9b8ca2b1df4948e9516697b1cf12f030968bd (diff)
downloadlinux-8a14f4d8328cc8615f8a5487c4173f36a8314796.tar.gz
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>
Diffstat (limited to 'lib')
-rw-r--r--lib/radix-tree.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index b1ca74489bc2..9b5d8a963897 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