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 S965372AbcAZMzE (ORCPT <rfc822;w@1wt.eu>);
	Tue, 26 Jan 2016 07:55:04 -0500
Received: from mga02.intel.com ([134.134.136.20]:48359 "EHLO mga02.intel.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S964860AbcAZMzA convert rfc822-to-8bit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 26 Jan 2016 07:55:00 -0500
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.22,350,1449561600"; 
   d="scan'208";a="901360510"
Date: Tue, 26 Jan 2016 07:54:56 -0500
From: Matthew Wilcox <willy@linux.intel.com>
To: "Williams, Dan J" <dan.j.williams@intel.com>
Cc: "kirill@shutemov.name" <kirill@shutemov.name>,
        "jack@suse.cz" <jack@suse.cz>,
        "syzkaller@googlegroups.com" <syzkaller@googlegroups.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kirill.shutemov@linux.intel.com" <kirill.shutemov@linux.intel.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "kcc@google.com" <kcc@google.com>, "vbabka@suse.cz" <vbabka@suse.cz>,
        "viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
        "dvyukov@google.com" <dvyukov@google.com>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "gthelen@google.com" <gthelen@google.com>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
        "mhocko@suse.com" <mhocko@suse.com>, "jack@suse.com" <jack@suse.com>,
        "glider@google.com" <glider@google.com>,
        "sasha.levin@oracle.com" <sasha.levin@oracle.com>,
        "Wilcox, Matthew R" <matthew.r.wilcox@intel.com>,
        "j-nomura@ce.jp.nec.com" <j-nomura@ce.jp.nec.com>
Subject: Re: mm: WARNING in __delete_from_page_cache
Message-ID: <20160126125456.GK2948@linux.intel.com>
References: <CACT4Y+aBnm8VLe5f=AwO2nUoQZaH-UVqUynGB+naAC-zauOQsQ@mail.gmail.com>
 <20160124230422.GA8439@node.shutemov.name>
 <20160125122206.GA24938@quack.suse.cz>
 <1453779754.32645.3.camel@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
In-Reply-To: <1453779754.32645.3.camel@intel.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Jan 26, 2016 at 03:42:34AM +0000, Williams, Dan J wrote:
> @@ -2907,7 +2912,12 @@ extern void replace_mount_options(struct super_block *sb, char *options);
>  
>  static inline bool io_is_direct(struct file *filp)
>  {
> -	return (filp->f_flags & O_DIRECT) || IS_DAX(file_inode(filp));

I think this should just be a one-liner:

-	return (filp->f_flags & O_DIRECT) || IS_DAX(file_inode(filp));
+	return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);

This does the right thing for block device inodes and filesystem inodes.
(see the opening stanzas of __dax_fault for an example).