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 94357CD4F39 for ; Fri, 15 May 2026 00:24:39 +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=m8DtHMHpdZM4pY6VH+I4/Yx3x192CtVNTK/xzy7Lpvw=; b=XEZxyKXnMTOQr2doHuEqkpjhoG FNmO4aAnVx67J91M7522WZJAZgzq10nuRL0RemtOkpPr69RPdVeSThzuMvkCtNey/zhqYehg8qOk3 h3bbcgCNCM3b7cU9fWTHYtJ3sW1txvQM8Lc/9nTnKTsyTgFQIRwV7IFop4lSrrOo8e0P/BpVLhLga W6FbFQ8MfaFvUjbxgy1zWvyzNpxqakk6i97GaCTTec8bEdJLYMKqo0cKXTV8gcHPjNfXcKv14l6AA MyueW/blhyi+hj67mDi9BjU5QL68xcx6bEr9gpXe+Q5KqyxZe/5OthC9dvHkFpKkVwgbmwnSWFcKs rzKhw33A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wNgM1-00000006uWp-0aav; Fri, 15 May 2026 00:24:37 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wNgLz-00000006uWd-3tKJ for linux-nvme@lists.infradead.org; Fri, 15 May 2026 00:24:35 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 2DAD360008; Fri, 15 May 2026 00:24:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4531C2BCB3; Fri, 15 May 2026 00:24:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778804674; bh=k4W7/pJA6lvhQOEmxL4Uw4hNh3lzjA73mTSZz6L891g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tD2BIK9VBTnBncsoHz8hImJBJ3vlvh7QDgIdEffKwFpWh0uZadfLaadKAdX2eqx3j 1O1Q4tGiZOyD91QPUiLS+AJb1VVGvzk4bkrysSZSuu9T6ccr8NM0SN4/pYGMoPJBHu AjE5BAOZuSMbBnRBtJ76U8gESt5i/B8vSKtGQYz4c0pOP4YcY6iFBJOxSIpORWYVMs M88egYe3bRFdeq8/MGmTwPRrsqGlGerf1O8hP7/FhsWbrSLsXRCwbsxnYAHC1uH9Q/ DRVqD9qXy3GZ3FbdGLytphLbGeOSMuoDzi7yZ4mSjK/pWw3PZxhBFqXt+KVXF2IHED 5iWXIx1088evA== Date: Thu, 14 May 2026 20:24:33 -0400 From: Mike Snitzer To: John Garry Cc: hch@lst.de, kbusch@kernel.org, sagi@grimberg.me, axboe@fb.com, martin.petersen@oracle.com, james.bottomley@hansenpartnership.com, hare@suse.com, bmarzins@redhat.com, nilay@linux.ibm.com, jmeneghi@redhat.com, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, michael.christie@oracle.com, dm-devel@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 00/13] libmultipath: a generic multipath lib for block drivers Message-ID: References: <20260428111105.1778008-1-john.g.garry@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260428111105.1778008-1-john.g.garry@oracle.com> 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, Apr 28, 2026 at 11:10:52AM +0000, John Garry wrote: > libmultipath: a generic multipath lib for block drivers > > This series introduces libmultipath. It is essentially a refactoring of > NVME multipath support, so we can have a common library to also support > native SCSI multipath. > > Much of the code is taken directly from the NVMe multipath code. However, > NVMe specifics are removed. A template structure is provided so the driver > may provide callbacks for driver specifics, like ANA support for NVMe. > > Important new structures introduced include: > > - mpath_head > These contain much of the multipath-specific functionality from > nvme_ns_head, including a pointer to the gendisk structure and > a path SRCU-based array. > > - mpath_device > This is the per-path structure, and contains much the same > multipath-specific functionality in nvme_ns > > libmultipath provides functionality for path management, path selection, > data path, and failover handling. > > Since the NVMe driver has some code in the sysfs and ioctl handling > which iterate all multipath NSes, functions like mpath_call_for_device() > are added to do the same per-path iteration. To get upstream this library needs an in-tree consumer. So at the end of the series, it'd makes sense to include the NVMe and/or SCSI changes that uses it. Mike