From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-16.italiaonline.it ([212.48.25.144]:56749 "EHLO smtp-16.italiaonline.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754384AbbCQXFW (ORCPT ); Tue, 17 Mar 2015 19:05:22 -0400 Message-ID: <5508B245.5080607@inwind.it> Date: Wed, 18 Mar 2015 00:01:25 +0100 From: Goffredo Baroncelli Reply-To: kreijack@inwind.it MIME-Version: 1.0 To: Wang Shilong , peer.loz@gmx.net CC: linux-btrfs@vger.kernel.org Subject: Re: Is it safe or useful to use NOCOW flag and autodefrag mount option at same time? References: In-Reply-To: Content-Type: text/plain; charset=windows-1252 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 2015-03-15 10:09, Wang Shilong wrote: Hi Wang, > > Btrfs use COW feautr to do defrag, acutally there was bug in the past > (nocow and defrag).. > > But make sure your kernel include following commit: > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=47059d930f0e002ff851beea87d738146804726d > > With above commit, i think autodefrag should work well with nocow. If I read correctly, autodefrag disables the NOcow behavior. This to me doesn't seem be "work well"; these are two incompatibles features: enabling autodefrag disables the nocow behavior on all files. Do I understood correctly ? BR G.Baroncelli -- gpg @keyserver.linux.it: Goffredo Baroncelli Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5