From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8036C04EB8 for ; Thu, 6 Dec 2018 14:49:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACB1F20661 for ; Thu, 6 Dec 2018 14:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544107744; bh=oVGQIz4XXiEGOftiRYiY1jIhPDOYSnxinYpNM4ouqKQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kyCNuXVOJByHl+my0nkKErmzPHgWXjutfWW1oXc+mLp08o2hzvLXkHC+OLB2X0rvb ILa+5Jgv8dAS8OlGcMAoHWE0WgZIIOnvJYyM8JZtNCUUsAJTSq1Kj1Ggb5lO/WiP/F KU8GtE9HIiG4B7OnV+5+beTDnQApjPmqWJUx5UX0= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACB1F20661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731208AbeLFOtD (ORCPT ); Thu, 6 Dec 2018 09:49:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:53436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730783AbeLFOsQ (ORCPT ); Thu, 6 Dec 2018 09:48:16 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 04CC020892; Thu, 6 Dec 2018 14:48:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544107695; bh=oVGQIz4XXiEGOftiRYiY1jIhPDOYSnxinYpNM4ouqKQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KpNAeRbqGZdX8nK/H1mnHqNH0JOBmYP1qoUhQBWzXz6hZaVhdf01LFlKKLVZWv+Hr BR+q/sX1vKYWnwcH6JdBCA5MTxFhKc1Bx00/PpJyuh7kKvO2lmcoI3bYLv37aOs0Rg p/YTXj+qf0ybF6YJpPASi+il/yotuR2CYCKYOkiY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Josef Bacik , Qu Wenruo , David Sterba , Ben Hutchings Subject: [PATCH 4.9 077/101] btrfs: tree-check: reduce stack consumption in check_dir_item Date: Thu, 6 Dec 2018 15:39:16 +0100 Message-Id: <20181206143016.555628642@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181206143011.174892052@linuxfoundation.org> References: <20181206143011.174892052@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Sterba commit e2683fc9d219430f5b78889b50cde7f40efeba7b upstream. I've noticed that the updated item checker stack consumption increased dramatically in 542f5385e20cf97447 ("btrfs: tree-checker: Add checker for dir item") tree-checker.c:check_leaf +552 (176 -> 728) The array is 255 bytes long, dynamic allocation would slow down the sanity checks so it's more reasonable to keep it on-stack. Moving the variable to the scope of use reduces the stack usage again tree-checker.c:check_leaf -264 (728 -> 464) Reviewed-by: Josef Bacik Reviewed-by: Qu Wenruo Signed-off-by: David Sterba Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/tree-checker.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -212,7 +212,6 @@ static int check_dir_item(struct btrfs_r di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); while (cur < item_size) { - char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)]; u32 name_len; u32 data_len; u32 max_name_len; @@ -295,6 +294,8 @@ static int check_dir_item(struct btrfs_r */ if (key->type == BTRFS_DIR_ITEM_KEY || key->type == BTRFS_XATTR_ITEM_KEY) { + char namebuf[max(BTRFS_NAME_LEN, XATTR_NAME_MAX)]; + read_extent_buffer(leaf, namebuf, (unsigned long)(di + 1), name_len); name_hash = btrfs_name_hash(namebuf, name_len);