From patchwork Thu Apr 14 14:16:35 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 8837551 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id ED7779F36E for ; Thu, 14 Apr 2016 14:26:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 06FA620270 for ; Thu, 14 Apr 2016 14:26:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A4DD20160 for ; Thu, 14 Apr 2016 14:26:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932339AbcDNOWG (ORCPT ); Thu, 14 Apr 2016 10:22:06 -0400 Received: from mga09.intel.com ([134.134.136.24]:35979 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756590AbcDNOWD (ORCPT ); Thu, 14 Apr 2016 10:22:03 -0400 Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga102.jf.intel.com with ESMTP; 14 Apr 2016 07:17:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,485,1455004800"; d="scan'208";a="686240908" Received: from unknown (HELO thog.int.wil.cx) ([10.254.90.221]) by FMSMGA003.fm.intel.com with SMTP; 14 Apr 2016 07:17:04 -0700 Received: by thog.int.wil.cx (Postfix, from userid 1000) id 60DE060326; Thu, 14 Apr 2016 10:17:01 -0400 (EDT) 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 14/29] radix-tree: Fix extending the tree for multi-order entries at offset 0 Date: Thu, 14 Apr 2016 10:16:35 -0400 Message-Id: <1460643410-30196-15-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-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The current code will insert entries at each level, as if we're going to add a new entry at the bottom level, so we then get an -EEXIST when we try to insert the entry into the tree. The best way to fix this is to not check 'order' when inserting into an empty tree. We still need to 'extend' the tree to the height necessary for the maximum index corresponding to this entry, so pass that value to radix_tree_extend() rather than the index we're asked to create, or we won't create a tree that's deep enough. Signed-off-by: Matthew Wilcox Reviewed-by: Ross Zwisler --- lib/radix-tree.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 272ce81..f13ddbb 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -432,7 +432,7 @@ static unsigned radix_tree_load_root(struct radix_tree_root *root, * Extend a radix tree so it can store key @index. */ static int radix_tree_extend(struct radix_tree_root *root, - unsigned long index, unsigned order) + unsigned long index) { struct radix_tree_node *node; struct radix_tree_node *slot; @@ -444,7 +444,7 @@ static int radix_tree_extend(struct radix_tree_root *root, while (index > radix_tree_maxindex(height)) height++; - if ((root->rnode == NULL) && (order == 0)) { + if (root->rnode == NULL) { root->height = height; goto out; } @@ -467,7 +467,7 @@ static int radix_tree_extend(struct radix_tree_root *root, node->count = 1; node->parent = NULL; slot = root->rnode; - if (radix_tree_is_indirect_ptr(slot) && newheight > 1) { + if (radix_tree_is_indirect_ptr(slot)) { slot = indirect_to_ptr(slot); slot->parent = node; slot = ptr_to_indirect(slot); @@ -478,7 +478,7 @@ static int radix_tree_extend(struct radix_tree_root *root, root->height = newheight; } while (height > root->height); out: - return 0; + return height * RADIX_TREE_MAP_SHIFT; } /** @@ -503,20 +503,26 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, void ***slotp) { struct radix_tree_node *node = NULL, *slot; + unsigned long maxindex; unsigned int height, shift, offset; - int error; + unsigned long max = index | ((1UL << order) - 1); + + shift = radix_tree_load_root(root, &slot, &maxindex); /* Make sure the tree is high enough. */ - if (index > radix_tree_maxindex(root->height)) { - error = radix_tree_extend(root, index, order); - if (error) + if (max > maxindex) { + int error = radix_tree_extend(root, max); + if (error < 0) return error; + shift = error; + slot = root->rnode; + if (order == shift) { + shift += RADIX_TREE_MAP_SHIFT; + root->height++; + } } - slot = root->rnode; - height = root->height; - shift = height * RADIX_TREE_MAP_SHIFT; offset = 0; /* uninitialised var warning */ while (shift > order) {