From owner-svn-src-all@FreeBSD.ORG Sat Apr 3 08:53:54 2010 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2E4111065672; Sat, 3 Apr 2010 08:53:54 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 1DF738FC13; Sat, 3 Apr 2010 08:53:54 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id o338rsV4036113; Sat, 3 Apr 2010 08:53:54 GMT (envelope-from avg@svn.freebsd.org) Received: (from avg@localhost) by svn.freebsd.org (8.14.3/8.14.3/Submit) id o338rrYB036111; Sat, 3 Apr 2010 08:53:53 GMT (envelope-from avg@svn.freebsd.org) Message-Id: <201004030853.o338rrYB036111@svn.freebsd.org> From: Andriy Gapon Date: Sat, 3 Apr 2010 08:53:53 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r206130 - head/sys/geom X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Apr 2010 08:53:54 -0000 Author: avg Date: Sat Apr 3 08:53:53 2010 New Revision: 206130 URL: http://svn.freebsd.org/changeset/base/206130 Log: g_vfs_open: allow only one mount per device vnode In other words, deny multiple read-only mounts of the same device. Shared read-only mounts should theoretically be possible, but, unfortunately, can not be implemented correctly using current buffer cache code/interface and results in an eventual system crash. Also, using nullfs seems to be a more efficient way to achieve the same goal. This gets us back to where we were before GEOM and where other BSDs are. Submitted by: pjd (idea for checking for shared mounting) Discussed with: phk, pjd Silence from: fs@, geom@ MFC after: 2 weeks Modified: head/sys/geom/geom_vfs.c Modified: head/sys/geom/geom_vfs.c ============================================================================== --- head/sys/geom/geom_vfs.c Sat Apr 3 08:39:00 2010 (r206129) +++ head/sys/geom/geom_vfs.c Sat Apr 3 08:53:53 2010 (r206130) @@ -161,6 +161,10 @@ g_vfs_open(struct vnode *vp, struct g_co g_topology_assert(); *cpp = NULL; + bo = &vp->v_bufobj; + if (bo->bo_private != vp) + return (EBUSY); + pp = g_dev_getprovider(vp->v_rdev); if (pp == NULL) return (ENOENT); @@ -176,7 +180,7 @@ g_vfs_open(struct vnode *vp, struct g_co vnode_create_vobject(vp, pp->mediasize, curthread); VFS_UNLOCK_GIANT(vfslocked); *cpp = cp; - bo = &vp->v_bufobj; + cp->private = vp; bo->bo_ops = g_vfs_bufops; bo->bo_private = cp; bo->bo_bsize = pp->sectorsize; @@ -196,5 +200,6 @@ g_vfs_close(struct g_consumer *cp) gp = cp->geom; bo = gp->softc; bufobj_invalbuf(bo, V_SAVE, 0, 0); + bo->bo_private = cp->private; g_wither_geom_close(gp, ENXIO); }