Calls RemoveSmbGlobalMapping when it necessary.

Author: vitaliy-leschenko

pkg/mounter/refcounter_windows.go

@@ -0,0 +1,122 @@
+//go:build windows
+// +build windows
+
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package mounter
+
+import (
+	"crypto/md5"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+var basePath = "c:\\csi\\smbmounts"
+var mutexes sync.Map
+
+func lock(key string) func() {
+	value, _ := mutexes.LoadOrStore(key, &sync.Mutex{})
+	mtx := value.(*sync.Mutex)
+	mtx.Lock()
+
+	return func() { mtx.Unlock() }
+}
+
+// getRootMappingPath - returns root of smb share path or empty string if the path is invalid. For example:
+//
+//	\\hostname\share\subpath   =>   \\hostname\share, error is nil
+//	\\hostname\share           =>   \\hostname\share, error is nil
+//	\\hostname                 =>   '', error is 'remote path (\\hostname) is invalid'
+func getRootMappingPath(path string) (string, error) {
+	items := strings.Split(path, "\\")
+	parts := []string{}
+	for _, s := range items {
+		if len(s) > 0 {
+			parts = append(parts, s)
+			if len(parts) == 2 {
+				break
+			}
+		}
+	}
+	if len(parts) != 2 {
+		return "", fmt.Errorf("remote path (%s) is invalid", path)
+	}
+	// parts[0] is a smb host name
+	// parts[1] is a smb share name
+	return strings.ToLower("\\\\" + parts[0] + "\\" + parts[1]), nil
+}
+
+// incementRemotePathReferencesCount - adds new reference between mappingPath and remotePath if it doesn't exist.
+// How it works:
+//  1. MappingPath contains two components: hostname, sharename
+//  2. We create directory in basePath related to each mappingPath. It will be used as container for references.
+//     Example: c:\\csi\\smbmounts\\hostname\\sharename
+//  3. Each reference is a file with name based on MD5 of remotePath. For debug it also will contains remotePath in body of the file.
+//     So, in incementRemotePathReferencesCount we create the file. In decrementRemotePathReferencesCount we remove the file.
+//     Example: c:\\csi\\smbmounts\\hostname\\sharename\\092f1413e6c1d03af8b5da6f44619af8
+func incementRemotePathReferencesCount(mappingPath, remotePath string) error {
+	remotePath = strings.TrimSuffix(remotePath, "\\")
+	path := filepath.Join(basePath, strings.TrimPrefix(mappingPath, "\\\\"))
+	if err := os.MkdirAll(path, os.ModeDir); err != nil {
+		return err
+	}
+	filePath := filepath.Join(path, getMd5(remotePath))
+	file, err := os.Create(filePath)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		file.Close()
+	}()
+
+	_, err = file.WriteString(remotePath)
+	return err
+}
+
+// decrementRemotePathReferencesCount - removes reference between mappingPath and remotePath.
+// See incementRemotePathReferencesCount to understand how references work.
+func decrementRemotePathReferencesCount(mappingPath, remotePath string) error {
+	remotePath = strings.TrimSuffix(remotePath, "\\")
+	path := filepath.Join(basePath, strings.TrimPrefix(mappingPath, "\\\\"))
+	if err := os.MkdirAll(path, os.ModeDir); err != nil {
+		return err
+	}
+	filePath := filepath.Join(path, getMd5(remotePath))
+	return os.Remove(filePath)
+}
+
+// getRemotePathReferencesCount - returns count of references between mappingPath and remotePath.
+// See incementRemotePathReferencesCount to understand how references work.
+func getRemotePathReferencesCount(mappingPath string) int {
+	path := filepath.Join(basePath, strings.TrimPrefix(mappingPath, "\\\\"))
+	if os.MkdirAll(path, os.ModeDir) != nil {
+		return -1
+	}
+	files, err := os.ReadDir(path)
+	if err != nil {
+		return -1
+	}
+	return len(files)
+}
+
+func getMd5(path string) string {
+	data := []byte(strings.ToLower(path))
+	return fmt.Sprintf("%x", md5.Sum(data))
+}

pkg/mounter/refcounter_windows_test.go

@@ -0,0 +1,227 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package mounter
+
+import (
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLockUnlock(t *testing.T) {
+	key := "resource name"
+
+	unlock := lock(key)
+	defer unlock()
+
+	_, loaded := mutexes.Load(key)
+	assert.True(t, loaded)
+}
+
+func TestLockLockedResource(t *testing.T) {
+	locked := true
+	unlock := lock("a")
+	go func() {
+		time.Sleep(500 * time.Microsecond)
+		locked = false
+		unlock()
+	}()
+
+	// try to lock already locked resource
+	unlock2 := lock("a")
+	defer unlock2()
+	if locked {
+		assert.Fail(t, "access to locked resource")
+	}
+}
+
+func TestLockDifferentKeys(t *testing.T) {
+	unlocka := lock("a")
+	unlockb := lock("b")
+	unlocka()
+	unlockb()
+}
+
+func TestGetRootMappingPath(t *testing.T) {
+	testCases := []struct {
+		remote       string
+		expectResult string
+		expectError  bool
+	}{
+		{
+			remote:       "",
+			expectResult: "",
+			expectError:  true,
+		},
+		{
+			remote:       "hostname",
+			expectResult: "",
+			expectError:  true,
+		},
+		{
+			remote:       "\\\\hostname\\path",
+			expectResult: "\\\\hostname\\path",
+			expectError:  false,
+		},
+		{
+			remote:       "\\\\hostname\\path\\",
+			expectResult: "\\\\hostname\\path",
+			expectError:  false,
+		},
+		{
+			remote:       "\\\\hostname\\path\\subpath",
+			expectResult: "\\\\hostname\\path",
+			expectError:  false,
+		},
+	}
+	for _, tc := range testCases {
+		result, err := getRootMappingPath(tc.remote)
+		if tc.expectError && err == nil {
+			t.Errorf("Expected error but getRootMappingPath returned a nil error")
+		}
+		if !tc.expectError {
+			if err != nil {
+				t.Errorf("Expected no errors but getRootMappingPath returned error: %v", err)
+			}
+			if tc.expectResult != result {
+				t.Errorf("Expected (%s) but getRootMappingPath returned (%s)", tc.expectResult, result)
+			}
+		}
+	}
+}
+
+func TestRemotePathReferencesCounter(t *testing.T) {
+	remotePath1 := "\\\\servername\\share\\subpath\\1"
+	remotePath2 := "\\\\servername\\share\\subpath\\2"
+	mappingPath, err := getRootMappingPath(remotePath1)
+	assert.Nil(t, err)
+
+	basePath = os.Getenv("TEMP") + "\\TestMappingPathCounter"
+	os.RemoveAll(basePath)
+	defer func() {
+		// cleanup temp folder
+		os.RemoveAll(basePath)
+	}()
+
+	// by default we have no any files in `mappingPath`. So, `count` should be zero
+	assert.Zero(t, getRemotePathReferencesCount(mappingPath))
+	// add reference to `remotePath1`. So, `count` should be equal `1`
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath1))
+	assert.Equal(t, 1, getRemotePathReferencesCount(mappingPath))
+	// add reference to `remotePath2`. So, `count` should be equal `2`
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath2))
+	assert.Equal(t, 2, getRemotePathReferencesCount(mappingPath))
+	// remove reference to `remotePath1`. So, `count` should be equal `1`
+	assert.Nil(t, decrementRemotePathReferencesCount(mappingPath, remotePath1))
+	assert.Equal(t, 1, getRemotePathReferencesCount(mappingPath))
+	// remove reference to `remotePath2`. So, `count` should be equal `0`
+	assert.Nil(t, decrementRemotePathReferencesCount(mappingPath, remotePath2))
+	assert.Zero(t, getRemotePathReferencesCount(mappingPath))
+}
+
+func TestIncementRemotePathReferencesCount(t *testing.T) {
+	remotePath := "\\\\servername\\share\\subpath"
+	mappingPath, err := getRootMappingPath(remotePath)
+	assert.Nil(t, err)
+
+	basePath = os.Getenv("TEMP") + "\\TestMappingPathCounter"
+	os.RemoveAll(basePath)
+	defer func() {
+		// cleanup temp folder
+		os.RemoveAll(basePath)
+	}()
+
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+
+	mappingPathContainer := basePath + "\\servername\\share"
+	if dir, err := os.Stat(mappingPathContainer); os.IsNotExist(err) || !dir.IsDir() {
+		t.Error("mapping file container does not exist")
+	}
+
+	reference := mappingPathContainer + "\\" + getMd5(remotePath)
+	if file, err := os.Stat(reference); os.IsNotExist(err) || file.IsDir() {
+		t.Error("reference file does not exist")
+	}
+}
+
+func TestDecrementRemotePathReferencesCount(t *testing.T) {
+	remotePath := "\\\\servername\\share\\subpath"
+	mappingPath, err := getRootMappingPath(remotePath)
+	assert.Nil(t, err)
+
+	basePath = os.Getenv("TEMP") + "\\TestMappingPathCounter"
+	os.RemoveAll(basePath)
+	defer func() {
+		// cleanup temp folder
+		os.RemoveAll(basePath)
+	}()
+
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+	assert.Nil(t, decrementRemotePathReferencesCount(mappingPath, remotePath))
+
+	mappingPathContainer := basePath + "\\servername\\share"
+	if dir, err := os.Stat(mappingPathContainer); os.IsNotExist(err) || !dir.IsDir() {
+		t.Error("mapping file container does not exist")
+	}
+
+	reference := mappingPathContainer + "\\" + getMd5(remotePath)
+	if _, err := os.Stat(reference); os.IsExist(err) {
+		t.Error("reference file exists")
+	}
+}
+
+func TestMultiplyCallsOfIncementRemotePathReferencesCount(t *testing.T) {
+	remotePath := "\\\\servername\\share\\subpath"
+	mappingPath, err := getRootMappingPath(remotePath)
+	assert.Nil(t, err)
+
+	basePath = os.Getenv("TEMP") + "\\TestMappingPathCounter"
+	os.RemoveAll(basePath)
+	defer func() {
+		// cleanup temp folder
+		os.RemoveAll(basePath)
+	}()
+
+	assert.Zero(t, getRemotePathReferencesCount(mappingPath))
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+	// next calls of `incementMappingPathCount` with the same arguments should be ignored
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+	assert.Equal(t, 1, getRemotePathReferencesCount(mappingPath))
+}
+
+func TestMultiplyCallsOfDecrementRemotePathReferencesCount(t *testing.T) {
+	remotePath := "\\\\servername\\share\\subpath"
+	mappingPath, err := getRootMappingPath(remotePath)
+	assert.Nil(t, err)
+
+	basePath = os.Getenv("TEMP") + "\\TestMappingPathCounter"
+	os.RemoveAll(basePath)
+	defer func() {
+		// cleanup temp folder
+		os.RemoveAll(basePath)
+	}()
+
+	assert.Zero(t, getRemotePathReferencesCount(mappingPath))
+	assert.Nil(t, incementRemotePathReferencesCount(mappingPath, remotePath))
+	assert.Nil(t, decrementRemotePathReferencesCount(mappingPath, remotePath))
+	assert.NotNil(t, decrementRemotePathReferencesCount(mappingPath, remotePath))
+}