Module Name: src
Committed By: hannken
Date: Fri Dec 10 09:20:38 UTC 2021
Modified Files:
src/sys/fs/union: union_vnops.c
Log Message:
Fix previous, don't copy up if the underlying node is unreadable.
To generate a diff of this commit:
cvs rdiff -u -r1.80 -r1.81 src/sys/fs/union/union_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/fs/union/union_vnops.c
diff -u src/sys/fs/union/union_vnops.c:1.80 src/sys/fs/union/union_vnops.c:1.81
--- src/sys/fs/union/union_vnops.c:1.80 Sun Dec 5 16:16:58 2021
+++ src/sys/fs/union/union_vnops.c Fri Dec 10 09:20:38 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: union_vnops.c,v 1.80 2021/12/05 16:16:58 hannken Exp $ */
+/* $NetBSD: union_vnops.c,v 1.81 2021/12/10 09:20:38 hannken Exp $ */
/*
* Copyright (c) 1992, 1993, 1994, 1995
@@ -72,7 +72,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.80 2021/12/05 16:16:58 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: union_vnops.c,v 1.81 2021/12/10 09:20:38 hannken Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -771,10 +771,20 @@ union_access(void *v)
}
}
+ /*
+ * Copy up to prevent checking (and failing) against
+ * underlying file system mounted read only.
+ * Check for read access first to prevent implicit
+ * copy of unaccessible underlying vnode.
+ */
if (un->un_uppervp == NULLVP &&
(un->un_lowervp->v_type == VREG) &&
(ap->a_accmode & VWRITE)) {
- error = union_copyup(un, 1, ap->a_cred, curlwp);
+ vn_lock(un->un_lowervp, LK_EXCLUSIVE | LK_RETRY);
+ error = VOP_ACCESS(un->un_lowervp, VREAD, ap->a_cred);
+ VOP_UNLOCK(un->un_lowervp);
+ if (error == 0)
+ error = union_copyup(un, 1, ap->a_cred, curlwp);
if (error)
return error;
}
