From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f50.google.com ([209.85.214.50]:35981 "EHLO mail-it0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754169AbdBNQqP (ORCPT ); Tue, 14 Feb 2017 11:46:15 -0500 Received: by mail-it0-f50.google.com with SMTP id c7so40349052itd.1 for ; Tue, 14 Feb 2017 08:46:15 -0800 (PST) Received: from [191.9.206.254] (rrcs-70-62-41-24.central.biz.rr.com. [70.62.41.24]) by smtp.gmail.com with ESMTPSA id z13sm552682ioz.3.2017.02.14.08.46.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 14 Feb 2017 08:46:13 -0800 (PST) Subject: Re: Unexpected behavior involving file attributes and snapshots. References: Cc: Btrfs BTRFS From: "Austin S. Hemmelgarn" Message-ID: <03288d87-0689-2cf5-0ab5-e625c97880dd@gmail.com> Date: Tue, 14 Feb 2017 11:46:10 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed To: unlisted-recipients:; (no To-header on input) Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 2017-02-14 11:07, Chris Murphy wrote: > On Tue, Feb 14, 2017 at 8:30 AM, Austin S. Hemmelgarn > wrote: >> I was just experimenting with snapshots on 4.9.0, and came across some >> unexpected behavior. >> >> The simple explanation is that if you snapshot a subvolume, any files in the >> subvolume that have the NOCOW attribute will not have that attribute in the >> snapshot. Some further testing indicates that this is the only file >> attribute that isn't preserved (I checked all the chattr flags that BTRFS >> supports). > > Huh, I can't reproduce this with 4.9.8 or 4.10rc7. systemd sets > journal files with chattr +C, and I do manual snapshots of rootfs > periodically, and those snapshots have journal files that have +C > still set. > Just tested on a different filesystem, and I'm not seeing it there either, I'll take a closer look at the FS I saw this on and see if I can figure out what's up.