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 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.lore.kernel.org (Postfix) with ESMTPS id 68023C27C53 for ; Wed, 12 Jun 2024 03:51:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=t0RTx3EaQ+M8bxrkBxK7TMUCfx+mnUwVjynNcSZ3MY4=; b=xEnQP77a0GaEMQkcKY9Od4Li/f wVteiiA36MEvnwRowyVW0+zcYQp6mbW+VunYYV43kDouOcKun6GP8WdvR4DGPHf5g9wDJNKcL7ozQ 2vE9gRaUYVT7dibKdQVRPuzuEaq3hgAna3yWtrWqrexdWZQFw0gmDAKjIpcFmR7/58FklXhf+H6g6 IreNVz4aBOSx2MVfmMsH14No8GyiICEzAZ0vMBin3IcpfWMmLcqPsC0dUUwMrT78AMriRkMxmMBzi +64B2gas8wFZCx2DSjPsLVm6omj2QoIPND8rANlACFJaZqq/wp0+3r5qYX8o5yQekYWLFQNpqyr5W Wq4l9HZA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHF1N-0000000Axrl-2eJg; Wed, 12 Jun 2024 03:51:37 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sHF1H-0000000AxoH-2IUr for linux-nvme@lists.infradead.org; Wed, 12 Jun 2024 03:51:34 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 939CE68BEB; Wed, 12 Jun 2024 05:51:22 +0200 (CEST) Date: Wed, 12 Jun 2024 05:51:22 +0200 From: Christoph Hellwig To: "Martin K. Petersen" Cc: Christoph Hellwig , Jens Axboe , Mike Snitzer , Mikulas Patocka , Song Liu , Yu Kuai , Dan Williams , Vishal Verma , Dave Jiang , Ira Weiny , Keith Busch , Sagi Grimberg , Chaitanya Kulkarni , linux-block@vger.kernel.org, dm-devel@lists.linux.dev, linux-raid@vger.kernel.org, nvdimm@lists.linux.dev, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, Bart Van Assche , Kanchan Joshi Subject: Re: [PATCH 03/11] block: remove the BIP_IP_CHECKSUM flag Message-ID: <20240612035122.GA25733@lst.de> References: <20240607055912.3586772-1-hch@lst.de> <20240607055912.3586772-4-hch@lst.de> <20240610115732.GA19790@lst.de> <20240610122423.GB21513@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240611_205131_770846_599B1949 X-CRM114-Status: GOOD ( 24.20 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Jun 11, 2024 at 03:51:27PM -0400, Martin K. Petersen wrote: > > But how do you even toggle the flag? There is no no code to do that. > > And if you already have a special kernel module for that it really > > should just use a passthrough request to take care of that. > > A passthrough command to the controller? A passthrough command to the LU that has a mismatching checksum. > > Note that unlike the NOCHECK flag which I just cleaned up because they > > were unused, this one actually does get in the way of the architecture > > of the whole series :( We could add a per-bip csum_type but it would > > feel really weird. > > Why would it feel weird? That's how it currently works. Because there's no way to have it set to anything but the per-queue one. > The qualification tool issues a flurry of commands injecting errors at > various places in the stack to identify that the right entity (block > layer, controller, storage device) catch a bad checksum, reference tag, > etc. How does it do that? There's no actualy way to make it mismatch.