From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anders Larsen Subject: Re: [PATCH] fs: push sync_filesystem() down to the file system's remount_fs() Date: Thu, 13 Mar 2014 15:50:03 +0100 Message-ID: <1394722203.5634.0@alarsen-lx> References: <1394720456-16629-1-git-send-email-tytso@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; DelSp=Yes; Format=Flowed Content-Transfer-Encoding: 8BIT Cc: linux-fsdevel@thunk.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig To: Theodore Ts'o Return-path: Received: from jesper.alarsen.net ([144.76.18.233]:55425 "EHLO mail.alarsen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751335AbaCMPAX convert rfc822-to-8bit (ORCPT ); Thu, 13 Mar 2014 11:00:23 -0400 In-Reply-To: <1394720456-16629-1-git-send-email-tytso@mit.edu> (from tytso@mit.edu on Thu Mar 13 15:20:56 2014) Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 2014-03-13 15:20, Theodore Ts'o wrote: > Previously, the no-op "mount -o mount /dev/xxx" operation when the > file system is already mounted read-write causes an implied, > unconditional syncfs(). This seems pretty stupid, and it's certainly > documented or guaraunteed to do this, nor is it particularly useful, > except in the case where the file system was mounted rw and is getting > remounted read-only. > > However, it's possible that there might be some file systems that are > actually depending on this behavior. In most file systems, it's > probably fine to only call sync_filesystem() when transitioning from > read-write to read-only, and there are some file systems where this is > not needed at all (for example, for a pseudo-filesystem or something > like romfs). qnx4 fs is read-only and thus doesn't need the sync_filesystem() at all, but as the sync shouldn't hurt: Acked-By: Anders Larsen