all: use consistent file permissions

Currently we have unix permissions for new files/dirs
hardcoded throughout the code base. Some places use 0644,
some - 0640, some - 0600 and a variety of other constants.

Introduce osutil.MkdirAll/WriteFile that use the default
permissions and use them throughout the code base.

This makes permissions consistent and also allows to easily
change the permissions later if we change our minds.

Also merge pkg/fileutil into pkg/osutil as they become
dependent on each other. The line between them was poorly
defined anyway as both operate on files.

1 files changed, 24 insertions, 0 deletions

diff --git a/pkg/osutil/fileutil_linux.go b/pkg/osutil/fileutil_linux.go
new file mode 100644
index 000000000..415c00353
--- /dev/null
+++ b/pkg/osutil/fileutil_linux.go
@@ -0,0 +1,24 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+package osutil
+
+import (
+	"io/ioutil"
+	"path/filepath"
+	"syscall"
+	"unsafe"
+)
+
+// UmountAll recurusively unmounts all mounts in dir.
+func UmountAll(dir string) {
+	files, _ := ioutil.ReadDir(dir)
+	for _, f := range files {
+		name := filepath.Join(dir, f.Name())
+		if f.IsDir() {
+			UmountAll(name)
+		}
+		fn := []byte(name + "\x00")
+		syscall.Syscall(syscall.SYS_UMOUNT2, uintptr(unsafe.Pointer(&fn[0])), syscall.MNT_FORCE, 0)
+	}
+}