From patchwork Tue Mar 23 12:46:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 12157699 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=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 F041BC433C1 for ; Tue, 23 Mar 2021 12:47:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B40D4619B1 for ; Tue, 23 Mar 2021 12:47:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231285AbhCWMqa (ORCPT ); Tue, 23 Mar 2021 08:46:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:39060 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231322AbhCWMq3 (ORCPT ); Tue, 23 Mar 2021 08:46:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9F7C8619B7; Tue, 23 Mar 2021 12:46:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616503588; bh=dKb4XHoIDXNLVg+qyrrG69FkzuESgHyQtMG/175Jr0E=; h=From:To:Cc:Subject:Date:From; b=mn4G5F2Q76qMPWsgaqnasyU9DR6HnK3afRUyNqF7giwnuVWMbolkSDWbtRnnrd1qF QeI51YC8ZBRuhVC0tN8XYfuoaBeKYDmGv+JLipyZhc4Z5QDmBUv1mRLFgemHqjeU87 7431ZkI0gkbWNYlH9BYAqt54rhsPXKGvo7Gu8Mxl2Y7BvlEL3MEgIaS2Cw5YxtVSuJ 4H3CAHXR592NKYKLc9H09iV0HG6znQxNNruqmX03met0sVD/W8c4tIWpqh/r1JU41S WR1YYWa6nCWZHLx2e0LwFfJh7ranM6SKDKAHCNbCEZoIQctCvCuXYtPVDThf/mTI/e Lk0CuVME+Wn8g== From: Arnd Bergmann To: Chris Mason , Josef Bacik , David Sterba , Anand Jain , Naohiro Aota Cc: Arnd Bergmann , Nikolay Borisov , Johannes Thumshirn , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] btrfs: zoned: fix uninitialized max_chunk_size Date: Tue, 23 Mar 2021 13:46:19 +0100 Message-Id: <20210323124624.1494552-1-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Arnd Bergmann The ctl->max_chunk_size member might be used uninitialized when none of the three conditions for initializing it in init_alloc_chunk_ctl_policy_zoned() are true: In function ‘init_alloc_chunk_ctl_policy_zoned’, inlined from ‘init_alloc_chunk_ctl’ at fs/btrfs/volumes.c:5023:3, inlined from ‘btrfs_alloc_chunk’ at fs/btrfs/volumes.c:5340:2: include/linux/compiler-gcc.h:48:45: error: ‘ctl.max_chunk_size’ may be used uninitialized [-Werror=maybe-uninitialized] 4998 | ctl->max_chunk_size = min(limit, ctl->max_chunk_size); | ^~~ fs/btrfs/volumes.c: In function ‘btrfs_alloc_chunk’: fs/btrfs/volumes.c:5316:32: note: ‘ctl’ declared here 5316 | struct alloc_chunk_ctl ctl; | ^~~ Initialize it to UINT_MAX and rely on the min() expression to limit it. Fixes: 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") Signed-off-by: Arnd Bergmann --- Note that the -Wmaybe-unintialized warning is globally disabled by default. For some reason I got this warning anyway when building this specific file with gcc-11. --- fs/btrfs/volumes.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index bc3b33efddc5..b42b423b6a10 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4980,6 +4980,7 @@ static void init_alloc_chunk_ctl_policy_zoned( u64 type = ctl->type; ctl->max_stripe_size = zone_size; + ctl->max_chunk_size = UINT_MAX; if (type & BTRFS_BLOCK_GROUP_DATA) { ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE, zone_size);