From patchwork Fri Nov 25 19:53:59 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabian Frederick X-Patchwork-Id: 9448083 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E170A6071C for ; Fri, 25 Nov 2016 19:54:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D14762787C for ; Fri, 25 Nov 2016 19:54:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C62DE27D5D; Fri, 25 Nov 2016 19:54:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 57DF42787C for ; Fri, 25 Nov 2016 19:54:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932654AbcKYTyr (ORCPT ); Fri, 25 Nov 2016 14:54:47 -0500 Received: from mailrelay110.isp.belgacom.be ([195.238.20.137]:11278 "EHLO mailrelay110.isp.belgacom.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932266AbcKYTyh (ORCPT ); Fri, 25 Nov 2016 14:54:37 -0500 X-Belgacom-Dynamic: yes X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A2BoAgDCljhY/9JLtVteDg4BAQQBAQoBA?= =?us-ascii?q?YM4AQEBAQEfgVqNRZdAkj+CDoIIhiGBZkAUAQIBAQEBAQEBYiiFRSNPSzeIca5?= =?us-ascii?q?Li3aGPolwhHceBZpUkQYCgXCIOIYISZE0HjeBFIMGAQuCBDw9NIZhBII5AQEB?= Received: from 210.75-181-91.adsl-dyn.isp.belgacom.be (HELO inkjet2.lan) ([91.181.75.210]) by relay.skynet.be with ESMTP; 25 Nov 2016 20:54:19 +0100 From: Fabian Frederick To: tytso@mit.edu Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, fabf@skynet.be Subject: [PATCH 1/1 linux-next] ext4: fix journal data documentation regarding O_DIRECT Date: Fri, 25 Nov 2016 20:53:59 +0100 Message-Id: <1480103639-25499-1-git-send-email-fabf@skynet.be> X-Mailer: git-send-email 2.7.4 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP O_DIRECT is declared disabled in data=journal mode but still served as buffered-IO when one would expect such operations to be canceled. This patch clarifies documentation and removes redundancy. Thanks to Theodore Ts'o for explanations. Signed-off-by: Fabian Frederick --- Documentation/filesystems/ext4.txt | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index 6c0108e..12bb488 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -157,10 +157,7 @@ noload if the filesystem was not unmounted cleanly, filesystem containing inconsistencies that can lead to any number of problems. -data=journal All data are committed into the journal prior to being - written into the main file system. Enabling - this mode will disable delayed allocation and - O_DIRECT support. +data=journal See journal mode below. data=ordered (*) All data are forced directly out to the main file system prior to its metadata being committed to the @@ -415,7 +412,8 @@ In the event of a crash, the journal can be replayed, bringing both data and metadata into a consistent state. This mode is the slowest except when data needs to be read from and written to disk at the same time where it outperforms all others modes. Enabling this mode will disable delayed -allocation and O_DIRECT support. +allocation and O_DIRECT support; the later being silently served using +buffered-IO. /proc entries =============