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authorKonstantin Khlebnikov <khlebnikov@openvz.org>2012-06-05 21:36:33 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-10 00:36:17 +0900
commitb642cb6a143da812f188307c2661c0357776a9d0 (patch)
tree2c88df819dc12d6a92bf72cce91eaad3ba62ec88 /lib
parentf940c5366eaaea9630ba643a036c2df321f66db3 (diff)
downloadlwn-b642cb6a143da812f188307c2661c0357776a9d0.tar.gz
lwn-b642cb6a143da812f188307c2661c0357776a9d0.zip
radix-tree: fix contiguous iterator
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 <khlebnikov@openvz.org> Reported-and-bisected-by: Hans de Bruin <jmdebruin@xmsnet.nl> Reported-and-bisected-by: Ondrej Zary <linux@rainbow-software.org> Reported-bisected-and-tested-by: Toralf Förster <toralf.foerster@gmx.de> Link: https://lkml.org/lkml/2012/6/5/64 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/radix-tree.c3
1 files changed, 3 insertions, 0 deletions
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)