From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B42131DC075; Mon, 18 Aug 2025 06:18:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755497917; cv=none; b=F5vvbKoPrCuxkpQl+ii2TyAGSFzfjoDQiYXnZVjYHvLAHZ73KE7UnjaXVzUmJuYhOTrFHKv0X2wGJCuqI4mz54wY8oV1kfzlYmO4h0A1R2/gl2XWTHlZO85v0bu//HaygW2susHoED/ymfPJcvIMGs99AtzD5ETpcNu875m2LRI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755497917; c=relaxed/simple; bh=gvgGwRBTrUDJK7ICfwrCyAPLE4fapCBnf1KZyNBQ6qM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tChuywb2Lz60reSg4D/FKsR7ePJFjbdtu2ya/6TxvQe0dDyPmUsjmmIf8hadlcpqbByChI5StpGVXII7eOyDZ52mLJBV9f9KxmBx9Npj8sTgNf90KYZ6CJUsWs3CFpOrcdjVM40PTsrfIxZWqKyZdwjV6OXb8RckitDRTXWhrpo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=G3yljLYy; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="G3yljLYy" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=v5X2+QvXc8JJyNSaaL1xliidRSYMQ5/OwHCSVyNzHxc=; b=G3yljLYy83oMDK4o1Oxjoz9H+U sDcRvvub+B2xGF+abpgOS9ggX3p2XieMTqiSGPf8Bn4o3mzbikrFUscObuPH2XkdPb9zngc1GmHuq 8YihdLdfLRnPrQNGjPNOs16ep4ubbi/a6L2B4m8D9fOyULzlKYBQlxIvznS4j0COC3EcGKRjrdNqh NdWzNP+YYRV3x/4qwYsGVH371D2KGK/NyKX73G4/6MxrQhuuziiPcqZIox10MwEFrEsESkh9gs6XB gpCdY02BMkLpGlLshDJ8yBZlYV4Lhoo/W9lqAD73mFltYIGXdhoabDJRqFpWDHM2amnpWxTUqF1NT VfUdPsgg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1untCT-00000006cZx-3zOq; Mon, 18 Aug 2025 06:18:33 +0000 Date: Sun, 17 Aug 2025 23:18:33 -0700 From: Christoph Hellwig To: Yu Kuai Cc: Christoph Hellwig , Damien Le Moal , colyli@kernel.org, linux-raid@vger.kernel.org, linux-block@vger.kernel.org, "yukuai (C)" Subject: Re: [PATCH 1/2] block: ignore underlying non-stack devices io_opt Message-ID: References: <20250817152645.7115-1-colyli@kernel.org> <756b587d-2a5c-4749-a03b-cfc786740684@kernel.org> <4aa48545-7398-c346-5968-5d08f29748c4@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Aug 18, 2025 at 02:14:06PM +0800, Yu Kuai wrote: > Please take a look at the first patch, nothing special, the new flag > will be passed to the top device. But passing it on will be incorrect in many cases, e.g. for any write caching solution. And that is a much more common use case than stacking different raid level using block layer stacking.