From patchwork Mon Dec 28 12:49:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 353011 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, USER_AGENT_GIT autolearn=unavailable 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 D8057C433DB for ; Mon, 28 Dec 2020 16:33:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0946207B6 for ; Mon, 28 Dec 2020 16:33:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730575AbgL1NFN (ORCPT ); Mon, 28 Dec 2020 08:05:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:32854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730569AbgL1NFM (ORCPT ); Mon, 28 Dec 2020 08:05:12 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C27CD22A84; Mon, 28 Dec 2020 13:04:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609160696; bh=M7feVJb4J5+v0RDefL6gJZZ685A7+llWtYvbk39kb8Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SqXTPzQu3J1fdYhPgr8vQgy/vHr+lp3zJUZP40ahe54G/XGBnRRkS6t+MCQ6Peg6l FuyZ/YB2Q9/1OrN/Wx3PrajiCxmdfUHd2mFhZrsHaykABKjyXzs+e4yxjQxdPg5Sk7 FhqnhW32JQc3uN0rMYjnGylrz+SqSJDbblqS9et8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefan Haberland , Jan Hoeppner , Jens Axboe Subject: [PATCH 4.9 139/175] s390/dasd: prevent inconsistent LCU device data Date: Mon, 28 Dec 2020 13:49:52 +0100 Message-Id: <20201228124859.981154467@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124853.216621466@linuxfoundation.org> References: <20201228124853.216621466@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stefan Haberland commit a29ea01653493b94ea12bb2b89d1564a265081b6 upstream. Prevent _lcu_update from adding a device to a pavgroup if the LCU still requires an update. The data is not reliable any longer and in parallel devices might have been moved on the lists already. This might lead to list corruptions or invalid PAV grouping. Only add devices to a pavgroup if the LCU is up to date. Additional steps are taken by the scheduled lcu update. Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland Reviewed-by: Jan Hoeppner Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/s390/block/dasd_alias.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -502,6 +502,14 @@ static int _lcu_update(struct dasd_devic return rc; spin_lock_irqsave(&lcu->lock, flags); + /* + * there is another update needed skip the remaining handling + * the data might already be outdated + * but especially do not add the device to an LCU with pending + * update + */ + if (lcu->flags & NEED_UAC_UPDATE) + goto out; lcu->pav = NO_PAV; for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) { switch (lcu->uac->unit[i].ua_type) { @@ -520,6 +528,7 @@ static int _lcu_update(struct dasd_devic alias_list) { _add_device_to_lcu(lcu, device, refdev); } +out: spin_unlock_irqrestore(&lcu->lock, flags); return 0; }