From owner-dev-commits-src-main@freebsd.org Fri Feb 12 01:07:14 2021 Return-Path: Delivered-To: dev-commits-src-main@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 5F9D453D60F; Fri, 12 Feb 2021 01:07:14 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DcFhc2J49z3N8m; Fri, 12 Feb 2021 01:07:11 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 65B181AFD1; Fri, 12 Feb 2021 01:07:11 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 11C17B5Z070576; Fri, 12 Feb 2021 01:07:11 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 11C17BYI070575; Fri, 12 Feb 2021 01:07:11 GMT (envelope-from git) Date: Fri, 12 Feb 2021 01:07:11 GMT Message-Id: <202102120107.11C17BYI070575@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: e4aaf35ab549 - main - nullfs: provide special bypass for VOP_VPUT_PAIR MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: e4aaf35ab54958f74409790fa2b7df8c2d230cee Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Feb 2021 01:07:15 -0000 The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=e4aaf35ab54958f74409790fa2b7df8c2d230cee commit e4aaf35ab54958f74409790fa2b7df8c2d230cee Author: Konstantin Belousov AuthorDate: 2021-01-24 13:22:48 +0000 Commit: Konstantin Belousov CommitDate: 2021-02-12 01:02:20 +0000 nullfs: provide special bypass for VOP_VPUT_PAIR Generic bypass cannot understand the rules of liveness for the VOP. Reviewed by: chs, mckusick Tested by: pho MFC after: 2 weeks Sponsored by: The FreeBSD Foundation --- sys/fs/nullfs/null_vnops.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c index 1de0cdfca9ac..45065e0be7b5 100644 --- a/sys/fs/nullfs/null_vnops.c +++ b/sys/fs/nullfs/null_vnops.c @@ -967,6 +967,54 @@ null_read_pgcache(struct vop_read_pgcache_args *ap) return (error); } +/* + * Avoid standard bypass, since lower dvp and vp could be no longer + * valid after vput(). + */ +static int +null_vput_pair(struct vop_vput_pair_args *ap) +{ + struct mount *mp; + struct vnode *dvp, *ldvp, *lvp, *vp, *vp1, **vpp; + int error, res; + + dvp = ap->a_dvp; + ldvp = NULLVPTOLOWERVP(dvp); + vref(ldvp); + + vpp = ap->a_vpp; + vp = NULL; + lvp = NULL; + if (vpp != NULL) { + vp = *vpp; + if (vp != NULL) { + vhold(vp); + mp = vp->v_mount; + lvp = NULLVPTOLOWERVP(vp); + if (ap->a_unlock_vp) + vref(lvp); + } + } + + res = VOP_VPUT_PAIR(ldvp, &lvp, ap->a_unlock_vp); + + /* lvp might have been unlocked and vp reclaimed */ + if (vp != NULL) { + if (!ap->a_unlock_vp && vp->v_vnlock != lvp->v_vnlock) { + error = null_nodeget(mp, lvp, &vp1); + if (error == 0) { + vput(vp); + *vpp = vp1; + } + } + if (ap->a_unlock_vp) + vrele(vp); + vdrop(vp); + } + vrele(dvp); + return (res); +} + /* * Global vfs data structures */ @@ -997,5 +1045,6 @@ struct vop_vector null_vnodeops = { .vop_vptocnp = null_vptocnp, .vop_vptofh = null_vptofh, .vop_add_writecount = null_add_writecount, + .vop_vput_pair = null_vput_pair, }; VFS_VOP_VECTOR_REGISTER(null_vnodeops);