Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932365AbcDNORx (ORCPT ); Thu, 14 Apr 2016 10:17:53 -0400 Received: from mga14.intel.com ([192.55.52.115]:31796 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754912AbcDNORt (ORCPT ); Thu, 14 Apr 2016 10:17:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,485,1455004800"; d="scan'208";a="85155970" From: Matthew Wilcox To: linux-kernel@vger.kernel.org, Andrew Morton Cc: Matthew Wilcox , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Konstantin Khlebnikov , Kirill Shutemov , Jan Kara , Neil Brown , Ross Zwisler Subject: [PATCH v2 25/29] radix-tree: Fix radix_tree_create for sibling entries Date: Thu, 14 Apr 2016 10:16:46 -0400 Message-Id: <1460643410-30196-26-git-send-email-willy@linux.intel.com> X-Mailer: git-send-email 2.8.0.rc3 In-Reply-To: <1460643410-30196-1-git-send-email-willy@linux.intel.com> References: <1460643410-30196-1-git-send-email-willy@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1758 Lines: 47 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 Reviewed-by: Ross Zwisler --- lib/radix-tree.c | 4 ++-- tools/testing/radix-tree/multiorder.c | 5 +++++ 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/lib/radix-tree.c b/lib/radix-tree.c index b1ca744..9b5d8a9 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 diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c index 1b6fc9b..fc93457 100644 --- a/tools/testing/radix-tree/multiorder.c +++ b/tools/testing/radix-tree/multiorder.c @@ -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); -- 2.8.0.rc3