From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 990526B03A2 for ; Tue, 18 Apr 2017 18:46:51 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id z185so4092906pgz.11 for ; Tue, 18 Apr 2017 15:46:51 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id a8si438813pgk.365.2017.04.18.15.46.50 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Apr 2017 15:46:50 -0700 (PDT) Date: Tue, 18 Apr 2017 15:46:47 -0700 From: Andrew Morton Subject: Re: [PATCH 1/4] fs: fix data invalidation in the cleancache during direct IO Message-Id: <20170418154647.9583bfa06705c614a2640a15@linux-foundation.org> In-Reply-To: <20170414140753.16108-2-aryabinin@virtuozzo.com> References: <20170414140753.16108-1-aryabinin@virtuozzo.com> <20170414140753.16108-2-aryabinin@virtuozzo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrey Ryabinin Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, Konrad Rzeszutek Wilk , Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , Steve French , Matthew Wilcox , Ross Zwisler , Trond Myklebust , Anna Schumaker , Jan Kara , Jens Axboe , Johannes Weiner , Alexey Kuznetsov , Christoph Hellwig , v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org On Fri, 14 Apr 2017 17:07:50 +0300 Andrey Ryabinin wrote: > Some direct write fs hooks call invalidate_inode_pages2[_range]() > conditionally iff mapping->nrpages is not zero. If page cache is empty, > buffered read following after direct IO write would get stale data from > the cleancache. > > Also it doesn't feel right to check only for ->nrpages because > invalidate_inode_pages2[_range] invalidates exceptional entries as well. > > Fix this by calling invalidate_inode_pages2[_range]() regardless of nrpages > state. I'm not understanding this. I can buy the argument about nrexceptional, but why does cleancache require the invalidate_inode_pages2_range) call even when ->nrpages is zero? I *assume* it's because invalidate_inode_pages2_range() calls cleancache_invalidate_inode(), yes? If so, can we please add this to the changelog? If not then please explain further. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org