Module Name: src
Committed By: riastradh
Date: Mon Mar 28 12:35:44 UTC 2022
Modified Files:
src/sys/miscfs/specfs: spec_vnops.c
Log Message:
specfs: sn_gone cannot be set while we hold the vnode lock.
Revoke runs with the vnode lock too, which is exclusive. Add an
assertion to this effect in spec_node_revoke to make it clear.
To generate a diff of this commit:
cvs rdiff -u -r1.194 -r1.195 src/sys/miscfs/specfs/spec_vnops.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/miscfs/specfs/spec_vnops.c
diff -u src/sys/miscfs/specfs/spec_vnops.c:1.194 src/sys/miscfs/specfs/spec_vnops.c:1.195
--- src/sys/miscfs/specfs/spec_vnops.c:1.194 Mon Mar 28 12:35:35 2022
+++ src/sys/miscfs/specfs/spec_vnops.c Mon Mar 28 12:35:44 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: spec_vnops.c,v 1.194 2022/03/28 12:35:35 riastradh Exp $ */
+/* $NetBSD: spec_vnops.c,v 1.195 2022/03/28 12:35:44 riastradh Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -58,7 +58,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.194 2022/03/28 12:35:35 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.195 2022/03/28 12:35:44 riastradh Exp $");
#include <sys/param.h>
#include <sys/proc.h>
@@ -402,6 +402,8 @@ spec_node_revoke(vnode_t *vp)
specnode_t *sn;
specdev_t *sd;
+ KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
+
sn = vp->v_specnode;
sd = sn->sn_dev;
@@ -552,11 +554,8 @@ spec_open(void *v)
/*
* Acquire an open reference -- as long as we hold onto it, and
- * the vnode isn't revoked, it can't be closed.
- *
- * But first check whether it has been revoked -- if so, we
- * can't acquire more open references and we must fail
- * immediately with EBADF.
+ * the vnode isn't revoked, it can't be closed, and the vnode
+ * can't be revoked until we release the vnode lock.
*/
mutex_enter(&device_lock);
switch (vp->v_type) {
@@ -565,10 +564,7 @@ spec_open(void *v)
* Character devices can accept opens from multiple
* vnodes.
*/
- if (sn->sn_gone) {
- error = EBADF;
- break;
- }
+ KASSERT(!sn->sn_gone);
sd->sd_opencnt++;
sn->sn_opencnt++;
break;
@@ -581,10 +577,7 @@ spec_open(void *v)
* Treat zero opencnt with non-NULL mountpoint as open.
* This may happen after forced detach of a mounted device.
*/
- if (sn->sn_gone) {
- error = EBADF;
- break;
- }
+ KASSERT(!sn->sn_gone);
if (sd->sd_opencnt != 0 || sd->sd_mountpoint != NULL) {
error = EBUSY;
break;
