From owner-svn-src-stable@FreeBSD.ORG Mon Dec 24 12:54:13 2012 Return-Path: Delivered-To: svn-src-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id DE070D16; Mon, 24 Dec 2012 12:54:12 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) by mx1.freebsd.org (Postfix) with ESMTP id C21F98FC0A; Mon, 24 Dec 2012 12:54:12 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.5/8.14.5) with ESMTP id qBOCsCQr007826; Mon, 24 Dec 2012 12:54:12 GMT (envelope-from kib@svn.freebsd.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.5/8.14.5/Submit) id qBOCsCdE007824; Mon, 24 Dec 2012 12:54:12 GMT (envelope-from kib@svn.freebsd.org) Message-Id: <201212241254.qBOCsCdE007824@svn.freebsd.org> From: Konstantin Belousov Date: Mon, 24 Dec 2012 12:54:12 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r244651 - in stable/9/sys: kern sys X-SVN-Group: stable-9 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Dec 2012 12:54:13 -0000 Author: kib Date: Mon Dec 24 12:54:12 2012 New Revision: 244651 URL: http://svnweb.freebsd.org/changeset/base/244651 Log: MFC r240283: Add MNTK_LOOKUP_EXCL_DOTDOT struct mount flag, which specifies to the lookup code that dotdot lookups shall override any shared lock requests with the exclusive one. The flag is useful for filesystems which sometimes need to upgrade shared lock to exclusive inside the VOP_LOOKUP or later, which cannot be done safely for dotdot, due to dvp also locked and causing LOR. Modified: stable/9/sys/kern/vfs_lookup.c stable/9/sys/sys/mount.h Directory Properties: stable/9/sys/ (props changed) Modified: stable/9/sys/kern/vfs_lookup.c ============================================================================== --- stable/9/sys/kern/vfs_lookup.c Mon Dec 24 10:10:18 2012 (r244650) +++ stable/9/sys/kern/vfs_lookup.c Mon Dec 24 12:54:12 2012 (r244651) @@ -393,11 +393,13 @@ namei(struct nameidata *ndp) } static int -compute_cn_lkflags(struct mount *mp, int lkflags) +compute_cn_lkflags(struct mount *mp, int lkflags, int cnflags) { - if (mp == NULL || - ((lkflags & LK_SHARED) && !(mp->mnt_kern_flag & MNTK_LOOKUP_SHARED))) { + if (mp == NULL || ((lkflags & LK_SHARED) && + (!(mp->mnt_kern_flag & MNTK_LOOKUP_SHARED) || + ((cnflags & ISDOTDOT) && + (mp->mnt_kern_flag & MNTK_LOOKUP_EXCL_DOTDOT))))) { lkflags &= ~LK_SHARED; lkflags |= LK_EXCLUSIVE; } @@ -526,7 +528,8 @@ lookup(struct nameidata *ndp) dp = ndp->ni_startdir; ndp->ni_startdir = NULLVP; vn_lock(dp, - compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY)); + compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | LK_RETRY, + cnp->cn_flags)); dirloop: /* @@ -683,7 +686,7 @@ dirloop: VFS_UNLOCK_GIANT(tvfslocked); vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | - LK_RETRY)); + LK_RETRY, ISDOTDOT)); } } @@ -721,7 +724,8 @@ unionlookup: vprint("lookup in", dp); #endif lkflags_save = cnp->cn_lkflags; - cnp->cn_lkflags = compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags); + cnp->cn_lkflags = compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags, + cnp->cn_flags); if ((error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp)) != 0) { cnp->cn_lkflags = lkflags_save; KASSERT(ndp->ni_vp == NULL, ("leaf should be empty")); @@ -740,7 +744,7 @@ unionlookup: VFS_UNLOCK_GIANT(tvfslocked); vn_lock(dp, compute_cn_lkflags(dp->v_mount, cnp->cn_lkflags | - LK_RETRY)); + LK_RETRY, cnp->cn_flags)); goto unionlookup; } @@ -812,8 +816,8 @@ unionlookup: dvfslocked = 0; vref(vp_crossmp); ndp->ni_dvp = vp_crossmp; - error = VFS_ROOT(mp, compute_cn_lkflags(mp, cnp->cn_lkflags), - &tdp); + error = VFS_ROOT(mp, compute_cn_lkflags(mp, cnp->cn_lkflags, + cnp->cn_flags), &tdp); vfs_unbusy(mp); if (vn_lock(vp_crossmp, LK_SHARED | LK_NOWAIT)) panic("vp_crossmp exclusively locked or reclaimed"); Modified: stable/9/sys/sys/mount.h ============================================================================== --- stable/9/sys/sys/mount.h Mon Dec 24 10:10:18 2012 (r244650) +++ stable/9/sys/sys/mount.h Mon Dec 24 12:54:12 2012 (r244651) @@ -369,6 +369,7 @@ void __mnt_vnode_markerfree(str #define MNTK_NO_IOPF 0x00000100 /* Disallow page faults during reads and writes. Filesystem shall properly handle i/o state on EFAULT. */ +#define MNTK_LOOKUP_EXCL_DOTDOT 0x00000800 #define MNTK_NOASYNC 0x00800000 /* disable async */ #define MNTK_UNMOUNT 0x01000000 /* unmount in progress */ #define MNTK_MWAIT 0x02000000 /* waiting for unmount to finish */