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 5E541C61DE3 for ; Sat, 21 Feb 2026 17:41:50 +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=FcflqHP8wP8tLQKnEOO9Ccml2hMLrq+0/CpPwhxRE7M=; b=TvrYP4wxrS4ITdZ38eY2neIEZ+ bWMWtJsxZIVACWlDSXvpaykw2AtnirpU4DaNBuPbi8spHoCz90bJSdrFfmEu+UpzeXN3z48Umfgxd bjNasSdPeQhszXKUJVQs9c9DVV9JgPFSRcWsUMdcCR/X+7cXmaMQ2ZmJrM3sA4xdNcFIrldmg7mVx p/5PQS/Ty0P3R9LMYQ5OnTb/2k8p7CTRYcKYoqlgI3UUfd5bkDekc6rruB3UCUhapBIS9TQ3Gl8aM DG0v2wcRvWL6exlRiBA9iQjlWEsQR8orfGo5P5sRyEVDUu15qzfxaDNQ7uU+hQTD1zCY2GIHGMpvO uOSBvNhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vtqz9-0000000GDJ5-1DHL; Sat, 21 Feb 2026 17:41:43 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vtqyz-0000000GDIU-1dBk for linux-nvme@lists.infradead.org; Sat, 21 Feb 2026 17:41:42 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id B2EAD407F2; Sat, 21 Feb 2026 17:41:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44B31C4CEF7; Sat, 21 Feb 2026 17:41:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771695690; bh=hC/bKukwvz707+9AogQXTJbFdJshNSgSwFm4eZcmcjM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZLZY01/u2Mj5XoC/TEIMxkn1Fyn4UOpnYAx04p7FeFCEMq1SbrqBA5WkhzTtI6kZb QFBx2zeeeONDEz0vZwpr1znz0VM59flDkyZUsvQ11iRioTnfrZY5b02mfaBO49+xkT gVIGx9J54pngaVg75opSFOrSuBqPazXU6im3VACIsoci3hh+mvxcqgHmuyOmrFJxlk PM3x4aiUzSceUFq3RvIcK9e6yWTGZYZgn4p1RIPgV1Lvzjful53O01jX92CcsdvXef C+BwuALX2iFuZVFbMf3f5j+3hnw2jdxCRNw49xhYSPafldjS/KvQ8ZczKvKSKrh8Bd jINjZMvYA9SXg== Date: Sat, 21 Feb 2026 12:41:28 -0500 From: Mike Snitzer To: John Garry Cc: lsf-pc@lists.linux-foundation.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, dm-devel@lists.linux.dev Subject: Re: [LSF/MM/BPF TOPIC] Native SCSI multipath support Message-ID: References: <69349b51-72c2-47f9-948f-f89843af62e4@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <69349b51-72c2-47f9-948f-f89843af62e4@oracle.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260221_094133_458010_F840EE57 X-CRM114-Status: GOOD ( 14.86 ) 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 Fri, Feb 13, 2026 at 02:19:11PM +0000, John Garry wrote: > At ALPSS 25 I presented a proposal for Native SCSI multipath support. Let's > discuss this topic at LSFMM. > > The idea for this is that SCSI could natively support multipath, like how > NVMe host driver does today. It is intended as an alternative to > dm-multipath support. > > I have been working on the implementation and I plan to post patches in the > next cycle. I am looking at a 3-stage approach: > a. create a driver-agnostic multipath library, very heavily based on NVMe > host multipath support. > The library would support features such as path management, path > selection/iopolicy, failover recovery, PR, delayed removal, gendisk > management etc. > b. switch NVMe over to use this library I can appreciate that the kernel to userspace interface of DM multipath is clearly unwanted (hence NVMe multipath and now SCSI multipath). But you should really be switching DM-multipath over to using it too; or at least detailing _why_ the core of DM multipath (drivers/md/dm-mpath.c) cannot be updated to use this common backend library. This line of work makes little sense to me if it just ignores dm-multipath. Mike > c. add native SCSI multipath support based on this common library > > Thanks, > John > > >