From nobody Fri Jul 3 18:58:58 2026 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4gsNMR3F7Hz6kKdm for ; Fri, 03 Jul 2026 18:58:59 +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 "YR1" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4gsNMR0f9mz3yH8 for ; Fri, 03 Jul 2026 18:58:59 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1783105139; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=mVAEsHcIFEk0pwR13L9kJUPMWil+KISdRDKW3ayrf0w=; b=NniyyJkmAY1Rz8ad15CUHOlWz9SHZPIInPcj30zibytCE+p4/e6pezqr3mhMGXn5d5S1IY YFvaZXx0PDQHHndh3D1mAWOrgo3lNk9JXV+URqc7rNm7rLQrXBbXC3NlPohlreeGPpwfwh aVUXMNbzH31kjxv9awq8xW0JQrSm/8j9+aw5dcxWH9Fwa78Oolo2AnCM1UdAsDTxKyDFAq OezS0t4olK7gypccw6sH4VPtjUVQ8R4M9O95NT7dOk78jYMCTCHRus98rUPcy471kCsuuE es8Y6CRsDHzFLfO7WIa1qDBRR+lNq6eanLBZyEKSwhnbz3gqa+9nHKheUPMmOQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1783105139; a=rsa-sha256; cv=none; b=ADzAgXKuASTY1pJMEmK2tUtBKtcECh2YLQ34BdiiZy55SwDcRvr9TtIFI4AxJdyH9hGWNu GQkbAR1pmsEj68HshSUupE1c1TC4GpsHY+phlsYCGYGKbNdnzBQyOQod84j+uj3xksc+y9 tEkrVbRXYzYYf4dEunxLIIOZdx7anYCNdLvyOfqepnAbSezhhMArFZpYU7RW4ES5eBXFUM PiU4+Z+KmST1b0W/OGFX3AhITzAB2img5/LqFdlUhxv1lJt9Yy/iZlP88gne11sXwLYknR LGHWKSjkS3JK0ssF70CwTgDDoYAE4nWqHe7G1KqedbBe1yzFPHxYe+m53cPVmA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1783105139; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=mVAEsHcIFEk0pwR13L9kJUPMWil+KISdRDKW3ayrf0w=; b=vn1/W/+Wf+bwAugZCZMXE1+OpV5MkCNKH1nf+UE62U/fqE9vagFbglJ7viFsV5J1NE9XMS swK3FwPzFh6juarA1C4VIXdw549BrxRH0mh+2ikeXogAgIskB3qvkfPurFQ07jy/sZBGsU VgAqFU12Ewb1jzIrZhpKlE+PVBOlSw4Pm9TF8AJYLEcml24FakijBcjQPS+K11dFqVJrr6 d2Qi738wqwyXFe3GdRWl12bbu19YRbtjdCtebWdf1RtUG2SL5U6cGDMtqCCd2SCSQ2F3Bi bFzKlWtLoPk5XHKIn9gGq6M6ueBuwB24+Sq0QMxlZfQb2mrbS/lWLYfsh3FnVA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4gsNMQ6QKsz113F for ; Fri, 03 Jul 2026 18:58:58 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 33785 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Fri, 03 Jul 2026 18:58:58 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Robert Wing Subject: git: 2de20c5c77cf - main - autofs: enable witness for autofs node lock List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: rew X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 2de20c5c77cf8d5b2059054cff0e0c1fc124739d Auto-Submitted: auto-generated Date: Fri, 03 Jul 2026 18:58:58 +0000 Message-Id: <6a480672.33785.206f5e6c@gitrepo.freebsd.org> The branch main has been updated by rew: URL: https://cgit.FreeBSD.org/src/commit/?id=2de20c5c77cf8d5b2059054cff0e0c1fc124739d commit 2de20c5c77cf8d5b2059054cff0e0c1fc124739d Author: Robert Wing AuthorDate: 2026-07-03 18:55:37 +0000 Commit: Robert Wing CommitDate: 2026-07-03 18:55:37 +0000 autofs: enable witness for autofs node lock Previously, an_vnode_lock was initialized with SX_NOWITNESS to silence lock order reversals. The reversals would occur when autofs_node_vn() was called with the directory vnode lock held, then lock an_vnode_lock, then lock the vnode attached to the autofs node. It looked like: directory vnode -> an_vnode_lock -> vnode attached to autofs node The established lock order is now vnode -> an_vnode_lock Currently, we don't have to worry about losing an autofs node during the unlock/lock as autofs nodes are only removed during an unmount() after vflush(). When autofs_node_vn() is called, the mountpoint has either been busied (preventing unmount) or a directory vnode is locked which prevents vflush() from finishing until the directory vnode is unlocked. Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D57857 --- sys/fs/autofs/autofs_vnops.c | 44 ++++++++++++++++++-------------------------- 1 file changed, 18 insertions(+), 26 deletions(-) diff --git a/sys/fs/autofs/autofs_vnops.c b/sys/fs/autofs/autofs_vnops.c index e8e47f20166a..b6424fc2ff4c 100644 --- a/sys/fs/autofs/autofs_vnops.c +++ b/sys/fs/autofs/autofs_vnops.c @@ -572,16 +572,7 @@ autofs_node_new(struct autofs_node *parent, struct autofs_mount *amp, anp->an_name = strdup(name, M_AUTOFS); anp->an_fileno = atomic_fetchadd_int(&->am_last_fileno, 1); callout_init(&anp->an_callout, 1); - /* - * The reason for SX_NOWITNESS here is that witness(4) - * cannot tell vnodes apart, so the following perfectly - * valid lock order... - * - * vnode lock A -> autofsvlk B -> vnode lock B - * - * ... gets reported as a LOR. - */ - sx_init_flags(&anp->an_vnode_lock, "autofsvlk", SX_NOWITNESS); + sx_init(&anp->an_vnode_lock, "autofsvlk"); getnanotime(&anp->an_ctime); anp->an_parent = parent; anp->an_mount = amp; @@ -645,6 +636,7 @@ autofs_node_vn(struct autofs_node *anp, struct mount *mp, int flags, { struct vnode *vp; int error; + enum vgetstate vs; AUTOFS_ASSERT_UNLOCKED(anp->an_mount); @@ -652,53 +644,53 @@ autofs_node_vn(struct autofs_node *anp, struct mount *mp, int flags, vp = anp->an_vnode; if (vp != NULL) { - error = vget(vp, flags | LK_RETRY); - if (error != 0) { - AUTOFS_WARN("vget failed with error %d", error); - sx_xunlock(&anp->an_vnode_lock); - return (error); - } +lockvp: + vs = vget_prep(vp); + sx_xunlock(&anp->an_vnode_lock); + vget_finish(vp, flags | LK_RETRY, vs); if (VN_IS_DOOMED(vp)) { /* * We got forcibly unmounted. */ AUTOFS_DEBUG("doomed vnode"); - sx_xunlock(&anp->an_vnode_lock); vput(vp); return (ENOENT); } *vpp = vp; - sx_xunlock(&anp->an_vnode_lock); return (0); } + sx_xunlock(&anp->an_vnode_lock); error = getnewvnode("autofs", mp, &autofs_vnodeops, &vp); - if (error != 0) { - sx_xunlock(&anp->an_vnode_lock); + if (error != 0) return (error); - } vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_type = VDIR; if (anp->an_parent == NULL) vp->v_vflag |= VV_ROOT; - vp->v_data = anp; - VN_LOCK_ASHARE(vp); error = insmntque(vp, mp); if (error != 0) { AUTOFS_DEBUG("insmntque() failed with error %d", error); - sx_xunlock(&anp->an_vnode_lock); return (error); } - KASSERT(anp->an_vnode == NULL, ("lost race")); + sx_xlock(&anp->an_vnode_lock); + if (anp->an_vnode != NULL) { + vp->v_op = &dead_vnodeops; + vp->v_data = NULL; + vgone(vp); + vput(vp); + vp = anp->an_vnode; + goto lockvp; + } + vp->v_data = anp; anp->an_vnode = vp; - sx_xunlock(&anp->an_vnode_lock); vn_set_state(vp, VSTATE_CONSTRUCTED);