From patchwork Wed May 12 14:42:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 438403 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, 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 A1FC4C43470 for ; Wed, 12 May 2021 15:56:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6624C6193E for ; Wed, 12 May 2021 15:56:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232198AbhELP5q (ORCPT ); Wed, 12 May 2021 11:57:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:52190 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233696AbhELPvt (ORCPT ); Wed, 12 May 2021 11:51:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 62905619D5; Wed, 12 May 2021 15:26:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620833188; bh=u8DTeNU9PR7drrQsSPr8yuvabY5xeHIC6Zj/xahhxlQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R7lmsSFiEincGEt4OhyXsUVez/V5OViqyI2Pz0Zvru/IGXRBZtc0XscrObXBLq1Vh GyWoj0XE2zO3vX0LBzreFIVqQwM55GTdbk6r2QpeUyuHBwFD0v07jm9Qfetoj9cvxG +DDxKVat8wt1UW+/mwc/dbtm0FxJpo5adcLv/Z/U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Glauber , Song Liu Subject: [PATCH 5.11 053/601] md: Fix missing unused status line of /proc/mdstat Date: Wed, 12 May 2021 16:42:10 +0200 Message-Id: <20210512144829.559879635@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144827.811958675@linuxfoundation.org> References: <20210512144827.811958675@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jan Glauber commit 7abfabaf5f805f5171d133ce6af9b65ab766e76a upstream. Reading /proc/mdstat with a read buffer size that would not fit the unused status line in the first read will skip this line from the output. So 'dd if=/proc/mdstat bs=64 2>/dev/null' will not print something like: unused devices: Don't return NULL immediately in start() for v=2 but call show() once to print the status line also for multiple reads. Cc: stable@vger.kernel.org Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") Signed-off-by: Jan Glauber Signed-off-by: Song Liu Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8187,7 +8187,11 @@ static void *md_seq_start(struct seq_fil loff_t l = *pos; struct mddev *mddev; - if (l >= 0x10000) + if (l == 0x10000) { + ++*pos; + return (void *)2; + } + if (l > 0x10000) return NULL; if (!l--) /* header */