From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sg-1-18.ptr.blmpb.com (sg-1-18.ptr.blmpb.com [118.26.132.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F1C2D155C97 for ; Wed, 17 Dec 2025 07:17:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=118.26.132.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765955880; cv=none; b=LJjL1e64OLUyYXK6pFM49NdvTpVqWDm9us5ipgomcLVado15ZTx9YH+tVvcmDP0JIPsrkI4dIJ+Mv2qgrPf1x6qHCt7LucZpF0QiQXdhg7uC9Hm1VD6xW/3Y+cNZaO9+MvW2LGOm5m2alPRLKpvmfCopC8vPPvr+iu8SDikC4qg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765955880; c=relaxed/simple; bh=pPBbEkwMbcZrXwJzmOjeqBsrG4Xd3AgbcxDnh2kQjbI=; h=In-Reply-To:To:Date:Message-Id:Mime-Version:Content-Type: References:From:Subject; b=K2Q+g5rbm+iMTNOksZEUNNpwzg9UBIcLmp05XR/047aoBznXPXjNwT2jdkwc4VkNZ+S/tWxpsLpDVCARoy/yhIg4BJSo6xAz4UhwmBFatNYM0LzfrF9lbyzYxqBr09TbxfsrTnyOy5bzZFMtDYZhZ44GGej8ta5M57AI9PwRbVE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fnnas.com; spf=pass smtp.mailfrom=fnnas.com; dkim=pass (2048-bit key) header.d=fnnas-com.20200927.dkim.feishu.cn header.i=@fnnas-com.20200927.dkim.feishu.cn header.b=h8ZzrV1n; arc=none smtp.client-ip=118.26.132.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=fnnas.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fnnas.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fnnas-com.20200927.dkim.feishu.cn header.i=@fnnas-com.20200927.dkim.feishu.cn header.b="h8ZzrV1n" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=s1; d=fnnas-com.20200927.dkim.feishu.cn; t=1765955871; h=from:subject:mime-version:from:date:message-id:subject:to:cc: reply-to:content-type:mime-version:in-reply-to:message-id; bh=pPBbEkwMbcZrXwJzmOjeqBsrG4Xd3AgbcxDnh2kQjbI=; b=h8ZzrV1nrM7L/0eWJ1Z7aPqFUG6ExXiniAIKg5LmmRdYouAtotWjkwQerqpSBC1NpIF6LX eFDMLAV2VNWpCfoJrCLHwfRz2dfTxIdysKXef+VPbd/Lwm7wjL6XUZEZTtNBkL3MIxjreS rJs9BKRsDuAdp7NGNYGtE31fa7FFnQ2pHBBbN2neXHJoX3ikdaFnxX89gz77RyGkEPIdQ5 58rcFt6/4E1Zg98M0jetzUqgYGErG1R06CVcqfPkCKi3vkhoakH2M3HlBOQpft01hqQkxh /PhdlP2g4Lv2x67sUgT9Vs1UwATgsUSPINcIR8/uott/RcIlyqwpPxJVk44TAw== In-Reply-To: <619a9b00-43dd-4897-8bb0-9ff29a760f52@gmail.com> To: "BugReports" , , , , Date: Wed, 17 Dec 2025 15:17:45 +0800 Content-Transfer-Encoding: quoted-printable User-Agent: Mozilla Thunderbird Message-Id: Precedence: bulk X-Mailing-List: linux-raid@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Received: from [192.168.1.104] ([39.182.0.136]) by smtp.feishu.cn with ESMTPS; Wed, 17 Dec 2025 15:17:48 +0800 Content-Type: text/plain; charset=UTF-8 Content-Language: en-US References: <8fd97a33-eb5a-4c88-ac8a-bfa1dd2ced61@fnnas.com> <619a9b00-43dd-4897-8bb0-9ff29a760f52@gmail.com> Reply-To: yukuai@fnnas.com From: "Yu Kuai" Subject: Re: Issues with md raid 1 on kernel 6.18 after booting kernel 6.19rc1 once X-Original-From: Yu Kuai X-Lms-Return-Path: Hi, =E5=9C=A8 2025/12/17 15:13, BugReports =E5=86=99=E9=81=93: > > ... > > We'll have to backport following patch into old kernels to make new=20 > arrays to assemble in old > kernels. > > .... > > > The md array which i am talking about was not created with kernel=20 > 6.19, it was created sometime in 2024. > > It was just used in kernel 6.19 and that broke compatibility with my=20 > 6.18 kernel. I know, I mean any array that is created or assembled in new kernels will n= ow have lsb field stored in metadata. This field is not defined in old kernels and = that's why array can't assembled in old kernels, due to unknown metadata. This is what we have to do for new features, and we're planning to avoid th= e forward compatibility issue with the above patch that I mentioned. --=20 Thansk, Kuai