From owner-freebsd-current@FreeBSD.ORG Sat Aug 6 14:43:29 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 92BA6106566C for ; Sat, 6 Aug 2011 14:43:29 +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 0E20A8FC0A for ; Sat, 6 Aug 2011 14:43:28 +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 p76EhP2v036273 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 6 Aug 2011 17:43:25 +0300 (EEST) (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 p76EhPGl043550; Sat, 6 Aug 2011 17:43:25 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4/Submit) id p76EhP3Q043549; Sat, 6 Aug 2011 17:43:25 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Sat, 6 Aug 2011 17:43:25 +0300 From: Kostik Belousov To: bf1783@gmail.com Message-ID: <20110806144325.GE17489@deviant.kiev.zoral.com.ua> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="IFgKI66spn1gqMCY" Content-Disposition: inline In-Reply-To: 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=-3.3 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-current@freebsd.org Subject: Re: Recursive nullfs mounts and r224655 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 06 Aug 2011 14:43:29 -0000 --IFgKI66spn1gqMCY Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Aug 06, 2011 at 04:44:25AM -0400, b. f. wrote: > Recent changes to the kernel (sys/kern/vfs_mount.c, in r224655?) > between r224550 and r224655 have broken my tinderbox setup. It had a > tmpfs filesystem mounted at /T and a UFS filesystem mounted at /U, > and, when setting up the tinderbox, performed: >=20 > mkdir /U/u1 > mkdir /U/u2 > mkdir /T/t1 > mount -t nullfs /T/t1 /U/u1 > mkdir-p /U/u1/u3/u4 > mount -t nullfs /U/u2 /U/u1/u3/u4 > ... >=20 > This worked at r224550 and before. It now fails at the second nullfs > mount, with ENOENT("mount_nullfs: No such file or directory"). r224615 and r224655 must be reverted. The reason for your trouble is that nullfs cannot cache any vnodes, thus reclaiming anything that get reference count of 0. This interacts badly with VOP_VNTOCNP() which has to operate on the vnodes with zero refcount, since we cannot decrement refcount under the namecache lock. Trying to update vptocnp(9) interface is too intrusive change for freeze period. --IFgKI66spn1gqMCY Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk49Uw0ACgkQC3+MBN1Mb4hZdgCg0pLjLMA5p8EMYTOkIBflD63m ecoAoM9+5K5eU2mgTz5J5i+7l7rofw7x =N+Ey -----END PGP SIGNATURE----- --IFgKI66spn1gqMCY--