From owner-freebsd-current@FreeBSD.ORG Wed May 21 23:21:01 2003 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1C3CC37B401; Wed, 21 May 2003 23:21:01 -0700 (PDT) Received: from gw.catspoiler.org (217-ip-163.nccn.net [209.79.217.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4630C43F3F; Wed, 21 May 2003 23:20:58 -0700 (PDT) (envelope-from truckman@FreeBSD.org) Received: from FreeBSD.org (mousie.catspoiler.org [192.168.101.2]) by gw.catspoiler.org (8.12.9/8.12.9) with ESMTP id h4M6KnM7075096; Wed, 21 May 2003 23:20:53 -0700 (PDT) (envelope-from truckman@FreeBSD.org) Message-Id: <200305220620.h4M6KnM7075096@gw.catspoiler.org> Date: Wed, 21 May 2003 23:20:49 -0700 (PDT) From: Don Lewis To: des@FreeBSD.org, jeff@FreeBSD.org MIME-Version: 1.0 Content-Type: TEXT/plain; charset=us-ascii cc: current@FreeBSD.org Subject: possible patch for vnode double unlock in pfs_lookup() X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 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: Thu, 22 May 2003 06:21:01 -0000 If the ISDOTDOT flag is set and the lockparent or ISLASTCN flags are not set, pfs_lookup() unlocks the same vnode twice. This can be observed by running find / -print with the DEBUG_VFS_LOCKS kernel option enabled. I think the following is the correct patch: I believe that it is safe to defer committing a fix until after 5.1-RELEASE. Index: sys/fs/pseudofs/pseudofs_vnops.c =================================================================== RCS file: /home/ncvs/src/sys/fs/pseudofs/pseudofs_vnops.c,v retrieving revision 1.35 diff -u -r1.35 pseudofs_vnops.c --- sys/fs/pseudofs/pseudofs_vnops.c 2 Mar 2003 22:23:45 -0000 1.35 +++ sys/fs/pseudofs/pseudofs_vnops.c 22 May 2003 04:40:09 -0000 @@ -411,7 +411,8 @@ vn_lock(vn, LK_EXCLUSIVE|LK_RETRY, cnp->cn_thread); cnp->cn_flags &= ~PDIRUNLOCK; } - if (!lockparent || !(cnp->cn_flags & ISLASTCN)) + if ((!lockparent || !(cnp->cn_flags & ISLASTCN)) && + !(cnp->cn_flags & ISDOTDOT)) VOP_UNLOCK(vn, 0, cnp->cn_thread); /*