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 5EBE733EB11 for ; Wed, 17 Dec 2025 17:12:03 +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=1765991527; cv=none; b=tuqipEgP89NricpxLLR3vHCC06a9DgFa94OTslU3mfleElIa0yDRq/FUiXA7bbtu5eJ9RPEcNtSJc3tdvmQyHS07cOvmhV7r7TzpRKPv5me8xHLLA8e06AZeqikRF+jvItnsAh0nIeTk++P7NV+JYZnhXXRMKePm5U+XCsZq3KY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765991527; c=relaxed/simple; bh=DSjq2RoIyhNvUNFOqu9um+RuSimk6KlrYztstsTZa/4=; h=To:From:Subject:Date:In-Reply-To:References:Cc:Content-Type: Message-Id:Mime-Version; b=Za+PphT1yjOKriy9ewTIEe25dS7j/BkkPQo5edFUlApoDKXyplsTfqudw6bx5aOzLpk7KhAvVAMnK3AkaOfAi/ScQOB9cjSCqj9v8NcTZ0nKXlUFv2hJnwNkkazi4ZjLeEDRHFtqJ4KZlz2kR0C7XbSmXeFySK75OYQZwt2xyXw= 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=CYzOzz+q; 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="CYzOzz+q" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=s1; d=fnnas-com.20200927.dkim.feishu.cn; t=1765991508; h=from:subject:mime-version:from:date:message-id:subject:to:cc: reply-to:content-type:mime-version:in-reply-to:message-id; bh=0EhvVRObfPvnEE8BjGaWdsdhDKkQN0iEJzYVBn07ElA=; b=CYzOzz+q0hcPgi+C4z9DnfxFziTsSHpAmdgfbMlr1K41alTK1jQGxnOTM66W3BdX7wWySi wGqoMY7+lGeFXNRxSAmqeVecbVNLRt1O0oyyOoszJQUKX6nsimemM0sYxlBC4XeBMsuL81 tRFnr4bDgPWsNL4iEk5tjc+fWGQaOrdpy7wSenH8e79woCf8qhzDGUoUhL5VjGcm3RwRbv wZU7+wHj11NoYgdaw3Z4zqE4tFbxP5LPsWWEHhGWHxuwZNyGNxnTGowIEtNz4OZIiHcEAJ P3pyreTzddtDypG+tdNik19nFe8cQRTmr8zJAvoCF+yCwKnKPe2zVJ75yoFCuA== To: "Greg KH" , From: "Yu Kuai" Subject: Re: [PATCH stable/6.18-6.17] md: add check_new_feature module parameter Date: Thu, 18 Dec 2025 01:11:43 +0800 In-Reply-To: <2025121700-pedicure-reckless-65b9@gregkh> Reply-To: yukuai@fnnas.com Content-Language: en-US Content-Transfer-Encoding: quoted-printable References: <20251217130513.2706844-1-linan666@huaweicloud.com> <2025121700-pedicure-reckless-65b9@gregkh> Cc: , , , , , , X-Original-From: Yu Kuai Content-Type: text/plain; charset=UTF-8 X-Lms-Return-Path: Message-Id: <6979cd43-d38c-477d-857c-8d211bc85474@fnnas.com> 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; Thu, 18 Dec 2025 01:11:45 +0800 User-Agent: Mozilla Thunderbird Hi, =E5=9C=A8 2025/12/17 22:04, Greg KH =E5=86=99=E9=81=93: > On Wed, Dec 17, 2025 at 09:05:13PM +0800, linan666@huaweicloud.com wrote: >> From: Li Nan >> >> commit 9c47127a807da3e36ce80f7c83a1134a291fc021 upstream. >> >> Raid checks if pad3 is zero when loading superblock from disk. Arrays >> created with new features may fail to assemble on old kernels as pad3 >> is used. >> >> Add module parameter check_new_feature to bypass this check. > This is a new feature, why does it need to go to stable kernels? > > And a module parameter? Ugh, this isn't the 1990's anymore, this is not > good and will be a mess over time (think multiple devices...) Nan didn't mention the background. We won't backport the new feature to sta= ble kernels(Although this fix a data lost problem in the case array is created with disks in different lbs, anyone is interested can do this). However, th= is backport is just used to provide a possible solution for user to still asse= mble arrays after switching to old LTS kernels when they are using the default l= bs. I think this is fine to provide forward compatibility, please let us know i= f you do not like this, or Nan should send a new version with explanation. > > thanks, > > greg k-h > --=20 Thansk, Kuai