From patchwork Thu May 26 16:36:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12862522 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7457DC433EF for ; Thu, 26 May 2022 16:36:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348152AbiEZQgX (ORCPT ); Thu, 26 May 2022 12:36:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245543AbiEZQgW (ORCPT ); Thu, 26 May 2022 12:36:22 -0400 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B528A3ED04; Thu, 26 May 2022 09:36:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=AnEIxfUMmcUWxMypKv8Fd+pUHTZRqVZQOmFGGbpQ8x4=; b=mC9Bb5u/4zA7cyUUg55DN+zbau Y5J9xLhpLpz7hmy8gM1fFUkZUDFdZw16IHtZ6CXkoDjEagDTbcY98JsqNsO49uJCtLpqVAW7x2DNB elNrIenlyMUQ1cGIlG+IP0cknHZQijYjkSUzo1y6hX7r148eX3lu9wpKWInuYFAhRTIEoh5GAdIee nvF2LhpthDkyeeddTfKfLF+WsNNmralMRHCmd5jGr8O0Jn64727w7VjvyFaHAUExDQz9tJn4uMFP8 lARUaNu/d1fENk/6ayHrR9eOjJTJRxnrnwNtz4XHObzWj4zlcGmcosBb9xhDmkEociOxEn2Hg5Jh1 LLbDemiA==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nuGTD-008A7R-Rm; Thu, 26 May 2022 10:36:20 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1nuGTB-0008Xz-4Y; Thu, 26 May 2022 10:36:17 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, Song Liu Cc: Christoph Hellwig , Donald Buczek , Guoqing Jiang , Xiao Ni , Stephen Bates , Martin Oliveira , David Sloan , Logan Gunthorpe Date: Thu, 26 May 2022 10:36:03 -0600 Message-Id: <20220526163604.32736-17-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220526163604.32736-1-logang@deltatee.com> References: <20220526163604.32736-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, song@kernel.org, hch@infradead.org, buczek@molgen.mpg.de, guoqing.jiang@linux.dev, xni@redhat.com, sbates@raithlin.com, Martin.Oliveira@eideticom.com, David.Sloan@eideticom.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v2 16/17] md: Ensure resync is reported after it starts X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org The 07layouts test in mdadm fails on some systems. The failure presents itself as the backup file not being removed before the next layout is grown into: mdadm: /dev/md0: cannot create backup file /tmp/md-test-backup: File exists This is because the background mdadm process, which is responsible for cleaning up this backup file gets into an infinite loop waiting for the reshape to start. mdadm checks the mdstat file if a reshape is going and, if it is not, it waits for an event on the file or times out in 5 seconds. On faster machines, the reshape may complete before the 5 seconds times out, and thus the background mdadm process loops waiting for a reshape to start that has already occurred. mdadm reads the mdstat file to start, but mdstat does not report that the reshape has begun, even though it has indeed begun. So the mdstat_wait() call (in mdadm) which polls on the mdstat file won't ever return until timing out. The reason mdstat reports the reshape has started is due to an issue in status_resync(). recovery_active is subtracted from curr_resync which will result in a value of zero for the first chunk of reshaped data, and the resulting read will report no reshape in progress. To fix this, if "resync - recovery_active" is an overloaded value, force the value to be MD_RESYNC_ACTIVE so the code reports a resync in progress. Signed-off-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig --- drivers/md/md.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 0893029865eb..2be429874d18 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8022,10 +8022,20 @@ static int status_resync(struct seq_file *seq, struct mddev *mddev) if (test_bit(MD_RECOVERY_DONE, &mddev->recovery)) /* Still cleaning up */ resync = max_sectors; - } else if (resync > max_sectors) + } else if (resync > max_sectors) { resync = max_sectors; - else + } else { resync -= atomic_read(&mddev->recovery_active); + if (resync < MD_RESYNC_ACTIVE) { + /* + * Resync has started, but the subtraction has + * yielded one of the special values. Force it + * to active to ensure the status reports an + * active resync. + */ + resync = MD_RESYNC_ACTIVE; + } + } if (resync == MD_RESYNC_NONE) { if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery)) {