lib/backup: fixes path generation for windows (#4133)

replaces custom fsync function with standard Fsync methods for files.
fixes pattern matching for parts and properly generate backup path for local fs.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70

app/vmbackup/main.go

@@ -155,7 +155,7 @@ See the docs at https://docs.victoriametrics.com/vmbackup.html .
 }
 
 func newSrcFS() (*fslocal.FS, error) {
-	snapshotPath := *storageDataPath + "/snapshots/" + *snapshotName
+	snapshotPath := filepath.Join(*storageDataPath, "snapshots", *snapshotName)
 
 	// Verify the snapshot exists.
 	f, err := os.Open(snapshotPath)

docs/CHANGELOG.md

@@ -43,6 +43,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 
 * BUGFIX: reduce the probability of sudden increase in the number of small parts on systems with small number of CPU cores.
 * BUGFIX: [vmctl](https://docs.victoriametrics.com/vmctl.html): fix performance issue when migrating data from VictoriaMetrics according to [these docs](https://docs.victoriametrics.com/vmctl.html#migrating-data-from-victoriametrics). Add the ability to speed up the data migration via `--vm-native-disable-retries` command-line flag. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4092).
+* BUGFIX: [vmbackup](https://docs.victoriametrics.com/vmbackup.html): fixes compatibility with Windows OS. For details see [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70)
 * BUGFIX: do not panic at windows during snapshot deletion. Note, at windows process restart required for complete snapshot delete. See [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/70#issuecomment-1491529183) for details.
 * BUGFIX: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): fix a panic when the duration in the query contains uppercase `M` suffix. Such a suffix isn't allowed to use in durations, since it clashes with `a million` suffix, e.g. it isn't clear whether `rate(metric[5M])` means rate over 5 minutes, 5 months or 5 million seconds. See [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3589) and [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/4120) issues.
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): retry failed read request on the closed connection one more time. This improves rules execution reliability when connection between vmalert and datasource closes unexpectedly.

lib/backup/actions/backup.go

@@ -4,7 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"strings"
+	"path/filepath"
 	"sync/atomic"
 	"time"
 
@@ -83,12 +83,7 @@ func (b *Backup) Run() error {
 }
 
 func storeMetadata(src *fslocal.FS, dst common.RemoteFS) error {
-	last := strings.LastIndex(src.Dir, "/")
-	if last < 0 {
-		return fmt.Errorf("cannot decode snapshot location %q", src.Dir)
-	}
-
-	snapshotName := src.Dir[last+1:]
+	snapshotName := filepath.Base(src.Dir)
 	snapshotTime, err := snapshot.Time(snapshotName)
 	if err != nil {
 		return fmt.Errorf("cannot decode snapshot name %q: %w", snapshotName, err)

lib/backup/actions/util.go

@@ -3,6 +3,7 @@ package actions
 import (
 	"flag"
 	"fmt"
+	"path/filepath"
 	"strings"
 	"sync"
 	"time"
@@ -190,7 +191,7 @@ func NewRemoteFS(path string) (common.RemoteFS, error) {
 	dir := path[n+len("://"):]
 	switch scheme {
 	case "fs":
-		if !strings.HasPrefix(dir, "/") {
+		if !filepath.IsAbs(dir) {
 			return nil, fmt.Errorf("dir must be absolute; got %q", dir)
 		}
 		fs := &fsremote.FS{

lib/backup/common/part.go

@@ -51,7 +51,7 @@ func (p *Part) RemotePath(prefix string) string {
 	return fmt.Sprintf("%s/%s/%016X_%016X_%016X", prefix, p.Path, p.FileSize, p.Offset, p.Size)
 }
 
-var partNameRegexp = regexp.MustCompile(`^(.+)/([0-9A-F]{16})_([0-9A-F]{16})_([0-9A-F]{16})$`)
+var partNameRegexp = regexp.MustCompile(`^(.+)[/\\]([0-9A-F]{16})_([0-9A-F]{16})_([0-9A-F]{16})$`)
 
 // ParseFromRemotePath parses p from remotePath.
 //

lib/backup/fscommon/fscommon.go

@@ -10,36 +10,6 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
-// FsyncFile fsyncs path contents and the parent directory contents.
-func FsyncFile(path string) error {
-	if err := fsync(path); err != nil {
-		_ = os.RemoveAll(path)
-		return fmt.Errorf("cannot fsync file %q: %w", path, err)
-	}
-	dir := filepath.Dir(path)
-	if err := fsync(dir); err != nil {
-		return fmt.Errorf("cannot fsync dir %q: %w", dir, err)
-	}
-	return nil
-}
-
-// FsyncDir fsyncs dir contents.
-func FsyncDir(dir string) error {
-	return fsync(dir)
-}
-
-func fsync(path string) error {
-	f, err := os.Open(path)
-	if err != nil {
-		return err
-	}
-	if err := f.Sync(); err != nil {
-		_ = f.Close()
-		return err
-	}
-	return f.Close()
-}
-
 // AppendFiles appends all the files from dir to dst.
 //
 // All the appended files will have dir prefix.
@@ -77,7 +47,7 @@ func appendFilesInternal(dst []string, d *os.File) ([]string, error) {
 			// Do not take into account special files.
 			continue
 		}
-		path := dir + "/" + name
+		path := filepath.Join(dir, name)
 		if fi.IsDir() {
 			// Process directory
 			dst, err = AppendFiles(dst, path)
@@ -112,13 +82,13 @@ func appendFilesInternal(dst []string, d *os.File) ([]string, error) {
 			if err != nil {
 				return nil, fmt.Errorf("cannot list files at %q from symlink %q: %w", pathReal, path, err)
 			}
-			pathReal += "/"
+			pathReal += string(filepath.Separator)
 			for i := len(dst); i < len(dstNew); i++ {
 				x := dstNew[i]
 				if !strings.HasPrefix(x, pathReal) {
 					return nil, fmt.Errorf("unexpected prefix for path %q; want %q", x, pathReal)
 				}
-				dstNew[i] = path + "/" + x[len(pathReal):]
+				dstNew[i] = filepath.Join(path, x[len(pathReal):])
 			}
 			dst = dstNew
 			continue
@@ -182,7 +152,7 @@ func removeEmptyDirsInternal(d *os.File) (bool, error) {
 		if name == "." || name == ".." {
 			continue
 		}
-		path := dir + "/" + name
+		path := filepath.Join(dir, name)
 		if fi.IsDir() {
 			// Process directory
 			ok, err := removeEmptyDirs(path)

lib/backup/fslocal/fslocal.go

@@ -68,7 +68,7 @@ func (fs *FS) ListParts() ([]common.Part, error) {
 	}
 
 	var parts []common.Part
-	dir += "/"
+	dir += string(filepath.Separator)
 	for _, file := range files {
 		if !strings.HasPrefix(file, dir) {
 			logger.Panicf("BUG: unexpected prefix for file %q; want %q", file, dir)
@@ -187,11 +187,7 @@ func (fs *FS) mkdirAll(filePath string) error {
 }
 
 func (fs *FS) path(p common.Part) string {
-	dir := fs.Dir
-	for strings.HasSuffix(dir, "/") {
-		dir = dir[:len(dir)-1]
-	}
-	return fs.Dir + "/" + p.Path
+	return filepath.Join(fs.Dir, p.Path)
 }
 
 type limitedReadCloser struct {
@@ -235,9 +231,11 @@ func (wc *writeCloser) Write(p []byte) (int, error) {
 }
 
 func (wc *writeCloser) Close() error {
+	wc.w.MustFlush(true)
 	wc.w.MustClose()
 	if wc.n != 0 {
 		return fmt.Errorf("missing data writes for %d bytes", wc.n)
 	}
-	return fscommon.FsyncFile(wc.path)
+
+	return nil
 }

lib/backup/fsremote/fsremote.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/backup/common"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/backup/fscommon"
+	libfs "github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
@@ -48,7 +49,7 @@ func (fs *FS) ListParts() ([]common.Part, error) {
 	}
 
 	var parts []common.Part
-	dir += "/"
+	dir += string(filepath.Separator)
 	for _, file := range files {
 		if !strings.HasPrefix(file, dir) {
 			logger.Panicf("BUG: unexpected prefix for file %q; want %q", file, dir)
@@ -101,7 +102,8 @@ func (fs *FS) CopyPart(srcFS common.OriginFS, p common.Part) error {
 	}
 	// Attempt to create hardlink from srcPath to dstPath.
 	if err := os.Link(srcPath, dstPath); err == nil {
-		return fscommon.FsyncFile(dstPath)
+		libfs.MustSyncPath(dstPath)
+		return nil
 	}
 
 	// Cannot create hardlink. Just copy file contents
@@ -115,6 +117,9 @@ func (fs *FS) CopyPart(srcFS common.OriginFS, p common.Part) error {
 		return fmt.Errorf("cannot create destination file: %w", err)
 	}
 	n, err := io.Copy(dstFile, srcFile)
+	if err := dstFile.Sync(); err != nil {
+		return fmt.Errorf("cannot fsync dstFile: %q: %w", dstFile.Name(), err)
+	}
 	if err1 := dstFile.Close(); err1 != nil {
 		err = err1
 	}
@@ -129,10 +134,6 @@ func (fs *FS) CopyPart(srcFS common.OriginFS, p common.Part) error {
 		_ = os.RemoveAll(dstPath)
 		return fmt.Errorf("unexpected number of bytes copied from %q to %q; got %d bytes; want %d bytes", srcPath, dstPath, n, p.Size)
 	}
-	if err := fscommon.FsyncFile(dstPath); err != nil {
-		_ = os.RemoveAll(dstPath)
-		return err
-	}
 	return nil
 }
 
@@ -167,6 +168,9 @@ func (fs *FS) UploadPart(p common.Part, r io.Reader) error {
 		return fmt.Errorf("cannot create file %q: %w", path, err)
 	}
 	n, err := io.Copy(w, r)
+	if err := w.Sync(); err != nil {
+		return fmt.Errorf("cannot fsync file: %q: %w", w.Name(), err)
+	}
 	if err1 := w.Close(); err1 != nil && err == nil {
 		err = err1
 	}
@@ -178,10 +182,6 @@ func (fs *FS) UploadPart(p common.Part, r io.Reader) error {
 		_ = os.RemoveAll(path)
 		return fmt.Errorf("wrong data size uploaded to %q; got %d bytes; want %d bytes", path, n, p.Size)
 	}
-	if err := fscommon.FsyncFile(path); err != nil {
-		_ = os.RemoveAll(path)
-		return err
-	}
 	return nil
 }
 
@@ -194,7 +194,7 @@ func (fs *FS) mkdirAll(filePath string) error {
 }
 
 func (fs *FS) path(p common.Part) string {
-	return p.RemotePath(fs.Dir)
+	return filepath.Join(fs.Dir, p.Path, fmt.Sprintf("%016X_%016X_%016X", p.FileSize, p.Offset, p.Size))
 }
 
 // DeleteFile deletes filePath at fs.