all: Convert folders to use filesystem abstraction

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4228

lib/config/config.go

@@ -23,6 +23,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/syncthing/syncthing/lib/fs"
 	"github.com/syncthing/syncthing/lib/protocol"
 	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/upgrade"
@@ -31,7 +32,7 @@ import (
 
 const (
 	OldestHandledVersion = 10
-	CurrentVersion       = 21
+	CurrentVersion       = 22
 	MaxRescanIntervalS   = 365 * 24 * 60 * 60
 )
 
@@ -319,6 +320,9 @@ func (cfg *Configuration) clean() error {
 	if cfg.Version == 20 {
 		convertV20V21(cfg)
 	}
+	if cfg.Version == 21 {
+		convertV21V22(cfg)
+	}
 
 	// Build a list of available devices
 	existingDevices := make(map[protocol.DeviceID]bool)
@@ -368,23 +372,38 @@ func (cfg *Configuration) clean() error {
 	return nil
 }
 
+func convertV21V22(cfg *Configuration) {
+	for i := range cfg.Folders {
+		cfg.Folders[i].FilesystemType = fs.FilesystemTypeBasic
+		// Migrate to templated external versioner commands
+		if cfg.Folders[i].Versioning.Type == "external" {
+			cfg.Folders[i].Versioning.Params["command"] += " %FOLDER_PATH% %FILE_PATH%"
+		}
+	}
+
+	cfg.Version = 22
+}
+
 func convertV20V21(cfg *Configuration) {
 	for _, folder := range cfg.Folders {
+		if folder.FilesystemType != fs.FilesystemTypeBasic {
+			continue
+		}
 		switch folder.Versioning.Type {
 		case "simple", "trashcan":
 			// Clean out symlinks in the known place
-			cleanSymlinks(filepath.Join(folder.Path(), ".stversions"))
+			cleanSymlinks(folder.Filesystem(), ".stversions")
 		case "staggered":
 			versionDir := folder.Versioning.Params["versionsPath"]
 			if versionDir == "" {
 				// default place
-				cleanSymlinks(filepath.Join(folder.Path(), ".stversions"))
+				cleanSymlinks(folder.Filesystem(), ".stversions")
 			} else if filepath.IsAbs(versionDir) {
 				// absolute
-				cleanSymlinks(versionDir)
+				cleanSymlinks(fs.NewFilesystem(fs.FilesystemTypeBasic, versionDir), ".")
 			} else {
 				// relative to folder
-				cleanSymlinks(filepath.Join(folder.Path(), versionDir))
+				cleanSymlinks(folder.Filesystem(), versionDir)
 			}
 		}
 	}
@@ -428,9 +447,7 @@ func convertV17V18(cfg *Configuration) {
 }
 
 func convertV16V17(cfg *Configuration) {
-	for i := range cfg.Folders {
-		cfg.Folders[i].Fsync = true
-	}
+	// Fsync = true removed
 
 	cfg.Version = 17
 }
@@ -670,21 +687,21 @@ loop:
 	return devices[0:count]
 }
 
-func cleanSymlinks(dir string) {
+func cleanSymlinks(filesystem fs.Filesystem, dir string) {
 	if runtime.GOOS == "windows" {
 		// We don't do symlinks on Windows. Additionally, there may
 		// be things that look like symlinks that are not, which we
 		// should leave alone. Deduplicated files, for example.
 		return
 	}
-	filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+	filesystem.Walk(dir, func(path string, info fs.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
-		if info.Mode()&os.ModeSymlink != 0 {
+		if info.IsSymlink() {
 			l.Infoln("Removing incorrectly versioned symlink", path)
-			os.Remove(path)
-			return filepath.SkipDir
+			filesystem.Remove(path)
+			return fs.SkipDir
 		}
 		return nil
 	})