Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751586AbdG0ItR (ORCPT ); Thu, 27 Jul 2017 04:49:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:55307 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750878AbdG0ItQ (ORCPT ); Thu, 27 Jul 2017 04:49:16 -0400 Date: Thu, 27 Jul 2017 10:49:14 +0200 From: Jan Kara To: Jeff Layton Cc: Alexander Viro , Jan Kara , "J . Bruce Fields" , Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Matthew Wilcox , Bob Peterson , Steven Whitehouse , cluster-devel@redhat.com Subject: Re: [PATCH v2 2/4] mm: add file_fdatawait_range and file_write_and_wait Message-ID: <20170727084914.GC21100@quack2.suse.cz> References: <20170726175538.13885-1-jlayton@kernel.org> <20170726175538.13885-3-jlayton@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170726175538.13885-3-jlayton@kernel.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 835 Lines: 27 On Wed 26-07-17 13:55:36, Jeff Layton wrote: > +int file_write_and_wait(struct file *file) > +{ > + int err = 0, err2; > + struct address_space *mapping = file->f_mapping; > + > + if ((!dax_mapping(mapping) && mapping->nrpages) || > + (dax_mapping(mapping) && mapping->nrexceptional)) { > + err = filemap_fdatawrite(mapping); > + /* See comment of filemap_write_and_wait() */ > + if (err != -EIO) { > + loff_t i_size = i_size_read(mapping->host); > + > + if (i_size != 0) > + __filemap_fdatawait_range(mapping, 0, > + i_size - 1); > + } > + } Err, what's the i_size check doing here? I'd just pass ~0 as the end of the range and ignore i_size. It is much easier than trying to wrap your head around possible races with file operations modifying i_size. Honza -- Jan Kara SUSE Labs, CR