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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CC32C4167B for ; Wed, 6 Dec 2023 13:31:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378577AbjLFNbe (ORCPT ); Wed, 6 Dec 2023 08:31:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378484AbjLFNbc (ORCPT ); Wed, 6 Dec 2023 08:31:32 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1779D45 for ; Wed, 6 Dec 2023 05:31:38 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E3A0C433C8; Wed, 6 Dec 2023 13:31:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1701869498; bh=OwMR4dVuXI2wfzttIoneLd+lFsP/aVlEanurpdeSjC0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HaS6U7HiH6L2Jq0Tm6s3ajg0QihHhtirXUWp2jr/7bjP0yZnvm5rNWGg26VCENBHa 1/cBP/Dwa3q4PlQMNSoIUgk1NOIZWv4cIetvO9yokKs+BHMMvOiwTPAH+ovtyysPOA k1mnQPCDqwpRJgK9mueMRSMBH1cQSaMeqIi/cr54= Date: Wed, 6 Dec 2023 22:31:36 +0900 From: Greg KH To: Yafang Shao Cc: rafael@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drivers: base: Introduce a new kernel parameter driver_sync_probe= Message-ID: <2023120644-pry-worried-22a2@gregkh> References: <20231206115355.4319-1-laoar.shao@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231206115355.4319-1-laoar.shao@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 06, 2023 at 11:53:55AM +0000, Yafang Shao wrote: > After upgrading our kernel from version 4.19 to 6.1, certain regressions > occurred due to the driver's asynchronous probe behavior. Specifically, > the SCSI driver transitioned to an asynchronous probe by default, resulting > in a non-fixed root disk behavior. In the prior 4.19 kernel, the root disk > was consistently identified as /dev/sda. However, with kernel 6.1, the root > disk can be any of /dev/sdX, leading to issues for applications reliant on > /dev/sda, notably impacting monitoring systems monitoring the root disk. Device names are never guaranteed to be stable, ALWAYS use a persistant names like a filesystem label or other ways. Look at /dev/disk/ for the needed ways to do this properly. > To address this, a new kernel parameter 'driver_sync_probe=' is introduced > to enforce synchronous probe behavior for specific drivers. This should be a per-bus thing, not a driver-specific thing as drivers for the same bus could have differing settings here which would cause a mess. Please just revert the scsi bus functionality if you have had regressions here, it's not a driver-core thing to do. thanks, greg k-h