From b642cb6a143da812f188307c2661c0357776a9d0 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Tue, 5 Jun 2012 21:36:33 +0400 Subject: radix-tree: fix contiguous iterator MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit fffaee365fded09f9ebf2db19066065fa54323c3 upstream. This patch fixes bug in macro radix_tree_for_each_contig(). If radix_tree_next_slot() sees NULL in next slot it returns NULL, but following radix_tree_next_chunk() switches iterating into next chunk. As result iterating becomes non-contiguous and breaks vfs "splice" and all its users. Signed-off-by: Konstantin Khlebnikov Reported-and-bisected-by: Hans de Bruin Reported-and-bisected-by: Ondrej Zary Reported-bisected-and-tested-by: Toralf Förster Link: https://lkml.org/lkml/2012/6/5/64 Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- lib/radix-tree.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'lib') diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 86516f5588e3..3ac50dc55638 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -673,6 +673,9 @@ void **radix_tree_next_chunk(struct radix_tree_root *root, * during iterating; it can be zero only at the beginning. * And we cannot overflow iter->next_index in a single step, * because RADIX_TREE_MAP_SHIFT < BITS_PER_LONG. + * + * This condition also used by radix_tree_next_slot() to stop + * contiguous iterating, and forbid swithing to the next chunk. */ index = iter->next_index; if (!index && iter->index) -- cgit v1.2.3