Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 25 Jul 2019 13:58:35 -0600
From:   Keith Busch <kbusch@kernel.org>
To:     Logan Gunthorpe <logang@deltatee.com>
Cc:     Matthew Wilcox <willy@infradead.org>, linux-kernel@vger.kernel.org,
        linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
        Sagi Grimberg <sagi@grimberg.me>, Jens Axboe <axboe@fb.com>,
        Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
        Max Gurtovoy <maxg@mellanox.com>,
        Stephen Bates <sbates@raithlin.com>
Subject: Re: [PATCH v6 04/16] nvme-core: introduce nvme_get_by_path()
Message-ID: <20190725195835.GA7317@localhost.localdomain>
References: <20190725172335.6825-1-logang@deltatee.com>
 <20190725172335.6825-5-logang@deltatee.com>
 <20190725175023.GA30641@bombadil.infradead.org>
 <da58f91e-6cfa-02e0-dd89-3cfa23764a0e@deltatee.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <da58f91e-6cfa-02e0-dd89-3cfa23764a0e@deltatee.com>
User-Agent: Mutt/1.9.1 (2017-09-22)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Jul 25, 2019 at 11:54:18AM -0600, Logan Gunthorpe wrote:
> 
> 
> On 2019-07-25 11:50 a.m., Matthew Wilcox wrote:
> > On Thu, Jul 25, 2019 at 11:23:23AM -0600, Logan Gunthorpe wrote:
> >> nvme_get_by_path() is analagous to blkdev_get_by_path() except it
> >> gets a struct nvme_ctrl from the path to its char dev (/dev/nvme0).
> >>
> >> The purpose of this function is to support NVMe-OF target passthru.
> > 
> > I can't find anywhere that you use this in this patchset.
> > 
> 
> Oh sorry, the commit message is out of date the function was actually
> called nvme_ctrl_get_by_path() and it's used in Patch 10.

Instead of by path, could we have configfs take something else, like
the unique controller instance or serial number? I know that's different
than how we handle blocks and files, but that way nvme core can lookup
the cooresponding controller without adding new cdev dependencies.