From owner-freebsd-fs@FreeBSD.ORG Wed Mar 23 14:37:34 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CB144106567D for ; Wed, 23 Mar 2011 14:37:34 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id 474C08FC14 for ; Wed, 23 Mar 2011 14:37:33 +0000 (UTC) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id p2NEbTdt008254 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 23 Mar 2011 16:37:29 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4) with ESMTP id p2NEbTpK026352; Wed, 23 Mar 2011 16:37:29 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4/Submit) id p2NEbTTf026351; Wed, 23 Mar 2011 16:37:29 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 23 Mar 2011 16:37:29 +0200 From: Kostik Belousov To: Lawrence Stewart Message-ID: <20110323143729.GA78089@deviant.kiev.zoral.com.ua> References: <4D8989A5.1020203@swin.edu.au> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bNaxTB0Vnic66+5h" Content-Disposition: inline In-Reply-To: <4D8989A5.1020203@swin.edu.au> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-3.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00, DNS_FROM_OPENWHOIS autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: freebsd-fs@freebsd.org Subject: Re: mount -o union doesn't allow changes to sub directories? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Mar 2011 14:37:34 -0000 --bNaxTB0Vnic66+5h Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Mar 23, 2011 at 04:48:21PM +1100, Lawrence Stewart wrote: > Hi again, >=20 > If I run something like: >=20 > mount -o union /dev/md0 /etc >=20 > where md0 is a memory backed fs device, and /etc is fully populated but > mounted RO off a CD, I can touch a new file in /etc, but can't in any > subdir of etc (fails with "Read-only filesystem" reported). >=20 > As far as I can tell this is a bug, but wanted to check if I'm > misunderstanding how the "-o union" mount option is supposed to work. No, this is how the union mount work. Union is performed only on the mount point directory, for the names that are absent in the directory. --bNaxTB0Vnic66+5h Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk2KBagACgkQC3+MBN1Mb4gJPwCfU2LOeCrR3O+fmArlSLOxdHZ4 67UAoL/sMPUkLoMS7UJ5QSlxss3wMhyT =fP+l -----END PGP SIGNATURE----- --bNaxTB0Vnic66+5h--