提交 fffaee36 编写于 作者: K Konstantin Khlebnikov 提交者: Linus Torvalds

radix-tree: fix contiguous iterator

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: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Reported-and-bisected-by: NHans de Bruin <jmdebruin@xmsnet.nl>
Reported-and-bisected-by: NOndrej Zary <linux@rainbow-software.org>
Reported-bisected-and-tested-by: NToralf Förster <toralf.foerster@gmx.de>
Link: https://lkml.org/lkml/2012/6/5/64
Cc: stable <stable@vger.kernel.org> # 3.4.x
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 f9ba7179
......@@ -368,8 +368,11 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
iter->index++;
if (likely(*slot))
return slot;
if (flags & RADIX_TREE_ITER_CONTIG)
if (flags & RADIX_TREE_ITER_CONTIG) {
/* forbid switching to the next chunk */
iter->next_index = 0;
break;
}
}
}
return NULL;
......
......@@ -686,6 +686,9 @@ 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)
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册