From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1757024AbcBBUO2 (ORCPT <rfc822;w@1wt.eu>);
	Tue, 2 Feb 2016 15:14:28 -0500
Received: from mga04.intel.com ([192.55.52.120]:40430 "EHLO mga04.intel.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1753415AbcBBUO0 (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Tue, 2 Feb 2016 15:14:26 -0500
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.22,386,1449561600"; 
   d="scan'208";a="739360417"
Date: Tue, 2 Feb 2016 15:14:22 -0500
From: Matthew Wilcox <willy@linux.intel.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>, Jan Kara <jack@suse.cz>,
        Dave Chinner <david@fromorbit.com>,
        Christoph Hellwig <hch@infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andrew Morton <akpm@linux-foundation.org>, Jan Kara <jack@suse.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-nvdimm <linux-nvdimm@ml01.01.org>
Subject: Re: [PATCH 2/2] dax: fix bdev NULL pointer dereferences
Message-ID: <20160202201422.GB3260@linux.intel.com>
References: <20160201145147.GD13740@quack.suse.cz>
 <20160201214730.GR20456@dastard>
 <20160202111723.GD12574@quack.suse.cz>
 <CAPcyv4j8MtNrsW86HepcS3JdO-Gkt+PCcS5GdPi1m3jwCsJ+nQ@mail.gmail.com>
 <20160202164642.GE12574@quack.suse.cz>
 <CAPcyv4hsChZS4Qv7XHpZm-qYuPrpTqgcpBC56jazE+y=B7q3CQ@mail.gmail.com>
 <20160202173456.GB23963@linux.intel.com>
 <CAPcyv4giawA3F0vdBFKbXVXu5bjYxjQWPE0ve9KMCcQh0uMDdg@mail.gmail.com>
 <20160202184643.GA3260@linux.intel.com>
 <CAPcyv4jf=4ea-C-Agh8FjDRJ1xkEpi0GTXFccdmwUADXfnAfrg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAPcyv4jf=4ea-C-Agh8FjDRJ1xkEpi0GTXFccdmwUADXfnAfrg@mail.gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Feb 02, 2016 at 10:59:41AM -0800, Dan Williams wrote:
> True, but in this case we're just trying to resolve the bdev for a
> inode / sector combination to already allocated storage.  So
> get_block() is a misnomer, this is just get_bdev() to resolve a
> super_block-inode+sector tuple to a bdev for cases when s_bdev is the
> wrong answer.

Then let's call it that.  i_ops->get_bdev(struct inode *inode, pgoff_t index)
And if it doesn't exist, use i_sb->s_bdev.