From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f177.google.com ([209.85.192.177]:35436 "EHLO mail-pf0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751137AbdAYEnV (ORCPT ); Tue, 24 Jan 2017 23:43:21 -0500 Received: by mail-pf0-f177.google.com with SMTP id f144so55255082pfa.2 for ; Tue, 24 Jan 2017 20:43:21 -0800 (PST) Date: Tue, 24 Jan 2017 20:42:53 -0800 From: Omar Sandoval To: Chris Murphy Cc: Btrfs BTRFS , agruenba@redhat.com Subject: Re: read-only fs, kernel 4.9.0, fs/btrfs/delayed-inode.c:1170 __btrfs_run_delayed_items, Message-ID: <20170125044253.GA18885@vader> References: <20170124185644.GA2853@vader> <20170124201038.GB2853@vader> <20170124202723.GD2853@vader> <20170124225052.GA10425@vader> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, Jan 24, 2017 at 07:53:06PM -0700, Chris Murphy wrote: > On Tue, Jan 24, 2017 at 3:50 PM, Omar Sandoval wrote: > > > Got this to repro after installing systemd-container. It's happening on > > lsetxattr() to set the SELinux context on /var/lib/machines, which is a > > subvolume. Looking into it now. Thanks for all of the help, Chris. > > Aha! So the snapshot part was a goose chase, it has nothing to do with > that, really. Because I'm taking a snapshot of root, the nested > /var/lib/machines subvolume is not in that snapshot, so now it has to > be created by systemd at next boot and the proper selinux label set on > it. > > It means there's something different about subvolumes and directories > when it comes to xattrs, and the xattr patch I found in bisect is > exposing the difference, hence things getting tripped up. The snapshots were actually the key -- the error was because setxattr() was being allowed on the read-only directory created in the place of the /var/lib/machines subvolume. Not sure if you saw the patch I sent up, but this should fix it: https://patchwork.kernel.org/patch/9536307/