Module Name: src
Committed By: mlelstv
Date: Wed Jun 2 15:59:08 UTC 2021
Modified Files:
src/sys/dev/dkwedge: dk.c
Log Message:
Copy mode of open wedges with the same parent and validate it.
Remove race on mode value when closing.
To generate a diff of this commit:
cvs rdiff -u -r1.103 -r1.104 src/sys/dev/dkwedge/dk.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/dev/dkwedge/dk.c
diff -u src/sys/dev/dkwedge/dk.c:1.103 src/sys/dev/dkwedge/dk.c:1.104
--- src/sys/dev/dkwedge/dk.c:1.103 Sat May 22 13:43:50 2021
+++ src/sys/dev/dkwedge/dk.c Wed Jun 2 15:59:08 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: dk.c,v 1.103 2021/05/22 13:43:50 mlelstv Exp $ */
+/* $NetBSD: dk.c,v 1.104 2021/06/02 15:59:08 mlelstv Exp $ */
/*-
* Copyright (c) 2004, 2005, 2006, 2007 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.103 2021/05/22 13:43:50 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.104 2021/06/02 15:59:08 mlelstv Exp $");
#ifdef _KERNEL_OPT
#include "opt_dkwedge.h"
@@ -1137,6 +1137,7 @@ static int
dkopen(dev_t dev, int flags, int fmt, struct lwp *l)
{
struct dkwedge_softc *sc = dkwedge_lookup(dev);
+ struct dkwedge_softc *nsc;
struct vnode *vp;
int error = 0;
int mode;
@@ -1169,13 +1170,24 @@ dkopen(dev_t dev, int flags, int fmt, st
}
if (error)
goto popen_fail;
- /* remember open mode */
- sc->sc_mode = mode;
sc->sc_parent->dk_rawvp = vp;
+ } else {
+ /*
+ * Retrieve mode from an already opened wedge.
+ */
+ mode = 0;
+ LIST_FOREACH(nsc, &sc->sc_parent->dk_wedges, sc_plink) {
+ if (nsc == sc || nsc->sc_dk.dk_openmask == 0)
+ continue;
+ mode = nsc->sc_mode;
+ break;
+ }
}
+ sc->sc_mode = mode;
sc->sc_parent->dk_rawopens++;
- } else if (flags & ~sc->sc_mode & FWRITE) {
- /* parent is opened read-only, cannot open read-write */
+ }
+ KASSERT(sc->sc_mode != 0);
+ if (flags & ~sc->sc_mode & FWRITE) {
error = EROFS;
goto popen_fail;
}
@@ -1199,7 +1211,9 @@ static int
dklastclose(struct dkwedge_softc *sc)
{
struct vnode *vp;
- int error = 0;
+ int error = 0, mode;
+
+ mode = sc->sc_mode;
vp = NULL;
if (sc->sc_parent->dk_rawopens > 0) {
@@ -1214,7 +1228,7 @@ dklastclose(struct dkwedge_softc *sc)
mutex_exit(&sc->sc_dk.dk_openlock);
if (vp) {
- dk_close_parent(vp, sc->sc_mode);
+ dk_close_parent(vp, mode);
}
return error;
@@ -1248,9 +1262,11 @@ dkclose(dev_t dev, int flags, int fmt, s
sc->sc_dk.dk_openmask =
sc->sc_dk.dk_copenmask | sc->sc_dk.dk_bopenmask;
- if (sc->sc_dk.dk_openmask == 0)
+ if (sc->sc_dk.dk_openmask == 0) {
error = dklastclose(sc); /* releases locks */
- else {
+ sc->sc_mode = 0;
+ } else {
+ sc->sc_mode = 0;
mutex_exit(&sc->sc_parent->dk_rawlock);
mutex_exit(&sc->sc_dk.dk_openlock);
}
