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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2BBE7C3F68F for ; Tue, 14 Jan 2020 00:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 029452084D for ; Tue, 14 Jan 2020 00:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729259AbgANAqL (ORCPT ); Mon, 13 Jan 2020 19:46:11 -0500 Received: from mga01.intel.com ([192.55.52.88]:44320 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726536AbgANAqL (ORCPT ); Mon, 13 Jan 2020 19:46:11 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Jan 2020 16:46:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,431,1571727600"; d="scan'208";a="247869908" Received: from iweiny-desk2.sc.intel.com ([10.3.52.157]) by fmsmga004.fm.intel.com with ESMTP; 13 Jan 2020 16:46:10 -0800 Date: Mon, 13 Jan 2020 16:46:10 -0800 From: Ira Weiny To: "Darrick J. Wong" Cc: linux-kernel@vger.kernel.org, Alexander Viro , Dan Williams , Dave Chinner , Christoph Hellwig , "Theodore Y. Ts'o" , Jan Kara , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [RFC PATCH V2 09/12] fs: Prevent mode change if file is mmap'ed Message-ID: <20200114004610.GD29860@iweiny-DESK2.sc.intel.com> References: <20200110192942.25021-1-ira.weiny@intel.com> <20200110192942.25021-10-ira.weiny@intel.com> <20200113222212.GO8247@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200113222212.GO8247@magnolia> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Mon, Jan 13, 2020 at 02:22:12PM -0800, Darrick J. Wong wrote: > On Fri, Jan 10, 2020 at 11:29:39AM -0800, ira.weiny@intel.com wrote: > > From: Ira Weiny > > [snip] > > > > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c > > index bc3654fe3b5d..1ab0906c6c7f 100644 > > --- a/fs/xfs/xfs_ioctl.c > > +++ b/fs/xfs/xfs_ioctl.c > > @@ -1200,6 +1200,14 @@ xfs_ioctl_setattr_dax_invalidate( > > goto out_unlock; > > } > > > > + /* > > + * If there is a mapping in place we must remain in our current mode. > > + */ > > + if (atomic64_read(&inode->i_mapped)) { > > Urk, should we really be messing around with the address space > internals? I contemplated a function call instead of checking i_mapped directly? Is that what you mean? > > > + error = -EBUSY; > > + goto out_unlock; > > + } > > + > > error = filemap_write_and_wait(inode->i_mapping); > > if (error) > > goto out_unlock; > > diff --git a/include/linux/fs.h b/include/linux/fs.h > > index 631f11d6246e..6e7dc626b657 100644 > > --- a/include/linux/fs.h > > +++ b/include/linux/fs.h > > @@ -740,6 +740,7 @@ struct inode { > > #endif > > > > void *i_private; /* fs or device private pointer */ > > + atomic64_t i_mapped; > > I would have expected to find this in struct address_space since the > mapping count is a function of the address space, right? I suppose but the only external call (above) would be passing an inode. So to me it seemed better here. Ira > > --D >