From: Theodore Tso Subject: Re: [PATCH] ext4: fix blkdev_issue_flush() failure handling Date: Sun, 29 Mar 2009 22:25:21 -0400 Message-ID: <20090330022521.GB13356@mit.edu> References: <200903291928.14451.bzolnier@gmail.com> <49CFB33A.9020406@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Bartlomiej Zolnierkiewicz , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: Eric Sandeen Return-path: Received: from THUNK.ORG ([69.25.196.29]:59633 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753921AbZC3CZ1 (ORCPT ); Sun, 29 Mar 2009 22:25:27 -0400 Content-Disposition: inline In-Reply-To: <49CFB33A.9020406@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Mar 29, 2009 at 12:43:22PM -0500, Eric Sandeen wrote: > > As long as we keep the call there this is probably good, but after > talking w/ Chris Mason, I think the call is extraneous anyway and should > probably just be removed... > Yes, I agree, but it takes a lot of digging to be completely sure of that it's safe to remove it. Interestingly, it was you who added the patch which added the call to blkdev_issue_flush(): commit d755fb384250d6bd7fd18a0930e71965acc8e72e Author: Eric Sandeen Date: Fri Jul 11 19:27:31 2008 -0400 ext4: call blkdev_issue_flush on fsync To ensure that bits are truly on-disk after an fsync, we should call blkdev_issue_flush if barriers are supported. Inspired by an old thread on barriers, by reiserfs & xfs which do the same, and by a patch SuSE ships with their kernel Signed-off-by: Eric Sandeen Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" When we remove it we should add a comment noting why it's not necessary. - Ted