Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752758AbbDALWu (ORCPT ); Wed, 1 Apr 2015 07:22:50 -0400 Received: from cantor2.suse.de ([195.135.220.15]:44539 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750848AbbDALWq (ORCPT ); Wed, 1 Apr 2015 07:22:46 -0400 Date: Wed, 1 Apr 2015 13:22:42 +0200 From: David Sterba To: Omar Sandoval Cc: "Eric W. Biederman" , Chris Mason , Josef Bacik , Timo Kokkonen , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] Btrfs: prevent deletion of mounted subvolumes Message-ID: <20150401112242.GG6821@suse.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Omar Sandoval , "Eric W. Biederman" , Chris Mason , Josef Bacik , Timo Kokkonen , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <64e28e67cbab0a2cd97411b848911414a743d83f.1427705646.git.osandov@osandov.com> <20150330123034.GB32051@suse.cz> <20150330184135.GA27227@mew.dhcp4.washington.edu> <87k2xwv6y8.fsf@x220.int.ebiederm.org> <20150401070328.GA27048@mew> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150401070328.GA27048@mew> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1072 Lines: 23 On Wed, Apr 01, 2015 at 12:03:28AM -0700, Omar Sandoval wrote: > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -1024,6 +1024,10 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) > struct btrfs_root *root = info->tree_root; > char *compress_type; > > + if (dentry != dentry->d_sb->s_root) { > + seq_puts(seq, ",subvol="); > + seq_dentry(seq, dentry, " \t\n\\"); Unfortunatelly this does not work if the default subvolume is not the toplevel one and the implicit mount (ie. without subvol=) is used. Then this leads to subvol=/ although it should be subvol=/the/default . There was a patch to build the path in the show_options callback, but it looked too heavy (taking locks, doing lookups). This is unrelated to the problem reported by Timo, though the fix might also fix this one. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/