Improve error handling and setting of xattr and file flags

- Improve error handling of file flags and xattrs. You now get warnings
- file flags on *BSD/Darwin use a mask and combine with the user/superuser
mask to prevent spurious warnings. The mask is not yet implemented as
a preference
- error handling/report for reading special files
- bump to go 1.20 for errors.Join

go.mod

@@ -1,6 +1,6 @@
 module github.com/gilbertchen/duplicacy
 
-go 1.19
+go 1.20
 
 require (
 	cloud.google.com/go v0.38.0
@@ -22,7 +22,7 @@ require (
 	github.com/minio/highwayhash v1.0.2
 	github.com/ncw/swift/v2 v2.0.1
 	github.com/pkg/sftp v1.11.0
-	github.com/pkg/xattr v0.4.1
+	github.com/pkg/xattr v0.4.9
 	github.com/vmihailenco/msgpack v4.0.4+incompatible
 	golang.org/x/crypto v0.12.0
 	golang.org/x/net v0.10.0

go.sum

@@ -128,6 +128,8 @@ github.com/pkg/sftp v1.11.0 h1:4Zv0OGbpkg4yNuUtH0s8rvoYxRCNyT29NVUo6pgPmxI=
 github.com/pkg/sftp v1.11.0/go.mod h1:lYOWFsE0bwd1+KfKJaKeuokY15vzFx25BLbzYYoAxZI=
 github.com/pkg/xattr v0.4.1 h1:dhclzL6EqOXNaPDWqoeb9tIxATfBSmjqL0b4DpSjwRw=
 github.com/pkg/xattr v0.4.1/go.mod h1:W2cGD0TBEus7MkUgv0tNZ9JutLtVO3cXu+IBRuHqnFs=
+github.com/pkg/xattr v0.4.9 h1:5883YPCtkSd8LFbs13nXplj9g9tlrwoJRjgpgMu1/fE=
+github.com/pkg/xattr v0.4.9/go.mod h1:di8WF84zAKk8jzR1UBTEWh9AUlIZZ7M/JNt8e9B6ktU=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
@@ -225,6 +227,7 @@ golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210514084401-e8d321eab015/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220408201424-a24fb2fb8a0f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
 golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=

src/duplicacy_backupmanager.go

@@ -826,7 +826,10 @@ func (manager *BackupManager) Restore(top string, revision int, inPlace bool, qu
 					return 0
 				}
 			}
-			remoteEntry.RestoreEarlyDirFlags(fullPath)
+			err = remoteEntry.RestoreEarlyDirFlags(fullPath, 0) // TODO: mask
+			if err != nil {
+				LOG_WARN("DOWNLOAD_FLAGS", "Failed to set early file flags on %s: %v", fullPath, err)
+			}
 			directoryEntries = append(directoryEntries, remoteEntry)
 		} else if remoteEntry.IsSpecial() {
 			if stat, _ := os.Lstat(fullPath); stat != nil {
@@ -1297,7 +1300,10 @@ func (manager *BackupManager) RestoreFile(chunkDownloader *ChunkDownloader, chun
 					LOG_ERROR("DOWNLOAD_CREATE", "Failed to create the file %s for in-place writing: %v", fullPath, err)
 					return false, nil
 				}
-				entry.RestoreEarlyFileFlags(existingFile)
+				err = entry.RestoreEarlyFileFlags(existingFile, 0) // TODO: implement mask
+				if err != nil {
+					LOG_WARN("DOWNLOAD_FLAGS", "Failed to set early file flags on %s: %v", fullPath, err)
+				}
 
 				n := int64(1)
 				// There is a go bug on Windows (https://github.com/golang/go/issues/21681) that causes Seek to fail
@@ -1481,7 +1487,10 @@ func (manager *BackupManager) RestoreFile(chunkDownloader *ChunkDownloader, chun
 				return false, nil
 			}
 		}
-		entry.RestoreEarlyFileFlags(existingFile)
+		err = entry.RestoreEarlyFileFlags(existingFile, 0) // TODO: implement mask
+		if err != nil {
+			LOG_WARN("DOWNLOAD_FLAGS", "Failed to set early file flags on %s: %v", fullPath, err)
+		}
 
 		existingFile.Seek(0, 0)
 
@@ -1564,7 +1573,10 @@ func (manager *BackupManager) RestoreFile(chunkDownloader *ChunkDownloader, chun
 			LOG_ERROR("DOWNLOAD_OPEN", "Failed to open file for writing: %v", err)
 			return false, nil
 		}
-		entry.RestoreEarlyFileFlags(newFile)
+		err = entry.RestoreEarlyFileFlags(newFile, 0) // TODO: implement mask
+		if err != nil {
+			LOG_WARN("DOWNLOAD_FLAGS", "Failed to set early file flags on %s: %v", fullPath, err)
+		}
 
 		hasher := manager.config.NewFileHasher()
 

src/duplicacy_entry.go

@@ -591,8 +591,9 @@ func (entry *Entry) RestoreMetadata(fullPath string, fileInfo os.FileInfo, setOw
 		}
 	}
 
-	if entry.Attributes != nil && len(*entry.Attributes) > 0 {
-		entry.SetAttributesToFile(fullPath)
+	err := entry.SetAttributesToFile(fullPath)
+	if err != nil {
+		LOG_WARN("RESTORE_ATTR", "Failed to set extended attributes on %s: %v", entry.Path, err)
 	}
 
 	// Note that chown can remove setuid/setgid bits so should be called before chmod
@@ -621,10 +622,10 @@ func (entry *Entry) RestoreMetadata(fullPath string, fileInfo os.FileInfo, setOw
 		}
 	}
 
-	// TODO Set flags last
-	// if entry.Attributes != nil && len(*entry.Attributes) > 0 {
-	// 	entry.SetFlagsToFile(fullPath)
-	// }
+	err = entry.RestoreLateFileFlags(fullPath, fileInfo, 0) // TODO: implement mask
+	if err != nil {
+		LOG_WARN("RESTORE_FLAGS", "Failed to set file flags on %s: %v", entry.Path, err)
+	}
 
 	return true
 }
@@ -842,9 +843,11 @@ func ListEntries(top string, path string, patterns []string, nobackupFile string
 			}
 		}
 
+		fullPath := joinPath(top, entry.Path)
+
 		if entry.IsLink() {
 			isRegular := false
-			isRegular, entry.Link, err = Readlink(joinPath(top, entry.Path))
+			isRegular, entry.Link, err = Readlink(fullPath)
 			if err != nil {
 				LOG_WARN("LIST_LINK", "Failed to read the symlink %s: %v", entry.Path, err)
 				skippedFiles = append(skippedFiles, entry.Path)
@@ -854,7 +857,7 @@ func ListEntries(top string, path string, patterns []string, nobackupFile string
 			if isRegular {
 				entry.Mode ^= uint32(os.ModeSymlink)
 			} else if path == "" && (filepath.IsAbs(entry.Link) || filepath.HasPrefix(entry.Link, `\\`)) && !strings.HasPrefix(entry.Link, normalizedTop) {
-				stat, err := os.Stat(joinPath(top, entry.Path))
+				stat, err := os.Stat(fullPath)
 				if err != nil {
 					LOG_WARN("LIST_LINK", "Failed to read the symlink: %v", err)
 					skippedFiles = append(skippedFiles, entry.Path)
@@ -873,14 +876,20 @@ func ListEntries(top string, path string, patterns []string, nobackupFile string
 				entry = newEntry
 			}
 		} else if entry.IsSpecial() {
-			if !entry.ReadSpecial(f) {
-				LOG_WARN("LIST_DEV", "Failed to save device node %s", entry.Path)
+			if err := entry.ReadSpecial(fullPath, f); err != nil {
+				LOG_WARN("LIST_DEV", "Failed to save device node %s: %v", entry.Path, err)
 				skippedFiles = append(skippedFiles, entry.Path)
 				continue
 			}
 		}
 
-		entry.ReadAttributes(top)
+		if err := entry.ReadAttributes(fullPath, f); err != nil {
+			LOG_WARN("LIST_ATTR", "Failed to read xattrs on %s: %v", entry.Path, err)
+		}
+
+		if err := entry.ReadFileFlags(fullPath, f); err != nil {
+			LOG_WARN("LIST_ATTR", "Failed to read file flags on %s: %v", entry.Path, err)
+		}
 
 		if excludeByAttribute && entry.Attributes != nil && excludedByAttribute(*entry.Attributes) {
 			LOG_DEBUG("LIST_EXCLUDE", "%s is excluded by attribute", entry.Path)

src/duplicacy_utils_darwin.go

@@ -7,112 +7,147 @@ package duplicacy
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
 	"os"
-	"path/filepath"
 	"strings"
 	"syscall"
 
 	"github.com/pkg/xattr"
+	"golang.org/x/sys/unix"
 )
 
-const darwin_UF_NODUMP = 0x1
+const (
+	darwinFileFlagsKey = "\x00bf"
+)
 
-const darwinFileFlagsKey = "\x00bf"
+var darwinIsSuperUser bool
+
+func init() {
+	darwinIsSuperUser = syscall.Geteuid() == 0
+}
 
 func excludedByAttribute(attributes map[string][]byte) bool {
 	value, ok := attributes["com.apple.metadata:com_apple_backup_excludeItem"]
 	excluded := ok && strings.Contains(string(value), "com.apple.backupd")
 	if !excluded {
-		value, ok := attributes[darwinFileFlagsKey]
-		excluded = ok && (binary.LittleEndian.Uint32(value) & darwin_UF_NODUMP) != 0
+		flags, ok := attributes[darwinFileFlagsKey]
+		excluded = ok && (binary.LittleEndian.Uint32(flags)&unix.UF_NODUMP) != 0
 	}
 	return excluded
 }
 
-func (entry *Entry) ReadAttributes(top string) {
-	fullPath := filepath.Join(top, entry.Path)
-	fileInfo, err := os.Lstat(fullPath)
-	if err != nil {
-		return
+func (entry *Entry) ReadAttributes(fullPath string, fi os.FileInfo) error {
+	if entry.IsSpecial() {
+		return nil
+	}
+
+	attributes, err := xattr.LList(fullPath)
+	if err != nil {
+		return err
 	}
 
-	if !entry.IsSpecial() {
-		attributes, _ := xattr.LList(fullPath)
 	if len(attributes) > 0 {
 		entry.Attributes = &map[string][]byte{}
+	}
+	var allErrors error
 	for _, name := range attributes {
-				attribute, err := xattr.LGet(fullPath, name)
-				if err == nil {
-					(*entry.Attributes)[name] = attribute
-				}
-			}
-		}
-	}
-	if err := entry.readFileFlags(fileInfo); err != nil {
-		LOG_INFO("ATTR_BACKUP", "Could not backup flags for file %s: %v", fullPath, err)
-	}
-}
-
-func (entry *Entry) SetAttributesToFile(fullPath string) {
-	if !entry.IsSpecial() {
-		names, _ := xattr.LList(fullPath)
-		for _, name := range names {
-			newAttribute, found := (*entry.Attributes)[name]
-			if found {
-				oldAttribute, _ := xattr.LGet(fullPath, name)
-				if !bytes.Equal(oldAttribute, newAttribute) {
-					xattr.LSet(fullPath, name, newAttribute)
-				}
-				delete(*entry.Attributes, name)
+		value, err := xattr.LGet(fullPath, name)
+		if err != nil {
+			allErrors = errors.Join(allErrors, err)
 		} else {
-				xattr.LRemove(fullPath, name)
+			(*entry.Attributes)[name] = value
 		}
 	}
 
-		for name, attribute := range *entry.Attributes {
-			if len(name) > 0 && name[0] == '\x00' {
-				continue
-			}
-			xattr.LSet(fullPath, name, attribute)
-		}
-	}
-	if err := entry.restoreLateFileFlags(fullPath); err != nil {
-		LOG_DEBUG("ATTR_RESTORE", "Could not restore flags for file %s: %v", fullPath, err)
-	}
+	return allErrors
 }
 
-func (entry *Entry) RestoreEarlyDirFlags(path string) error {
-	return nil
-}
-
-func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
-	return nil
-}
-
-func (entry *Entry) readFileFlags(fileInfo os.FileInfo) error {
-	stat, ok := fileInfo.Sys().(*syscall.Stat_t)
-	if ok && stat.Flags != 0 {
+func (entry *Entry) ReadFileFlags(fullPath string, fileInfo os.FileInfo) error {
+	stat, _ := fileInfo.Sys().(*syscall.Stat_t)
+	if stat != nil && stat.Flags != 0 {
 		if entry.Attributes == nil {
 			entry.Attributes = &map[string][]byte{}
 		}
 		v := make([]byte, 4)
 		binary.LittleEndian.PutUint32(v, stat.Flags)
 		(*entry.Attributes)[darwinFileFlagsKey] = v
-		LOG_DEBUG("ATTR_READ", "Read flags 0x%x for %s", stat.Flags, entry.Path)
 	}
 	return nil
 }
 
-func (entry *Entry) restoreLateFileFlags(path string) error {
-	if entry.Attributes == nil {
+func (entry *Entry) SetAttributesToFile(fullPath string) error {
+	if entry.Attributes == nil || len(*entry.Attributes) == 0 || entry.IsSpecial() {
 		return nil
 	}
-	if v, have := (*entry.Attributes)[darwinFileFlagsKey]; have {
-		f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_SYMLINK, 0)
+	attributes := *entry.Attributes
+
+	if _, haveFlags := attributes[darwinFileFlagsKey]; haveFlags && len(attributes) <= 1 {
+		return nil
+	}
+
+	names, err := xattr.LList(fullPath)
 	if err != nil {
 		return err
 	}
-		err = syscall.Fchflags(int(f.Fd()), int(binary.LittleEndian.Uint32(v)))
+	for _, name := range names {
+		newAttribute, found := attributes[name]
+		if found {
+			oldAttribute, _ := xattr.LGet(fullPath, name)
+			if !bytes.Equal(oldAttribute, newAttribute) {
+				err = errors.Join(err, xattr.LSet(fullPath, name, newAttribute))
+			}
+			delete(attributes, name)
+		} else {
+			err = errors.Join(err, xattr.LRemove(fullPath, name))
+		}
+	}
+
+	for name, attribute := range attributes {
+		if len(name) > 0 && name[0] == '\x00' {
+			continue
+		}
+		err = errors.Join(err, xattr.LSet(fullPath, name, attribute))
+	}
+	return err
+}
+
+func (entry *Entry) RestoreEarlyDirFlags(fullPath string, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyFileFlags(f *os.File, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreLateFileFlags(fullPath string, fileInfo os.FileInfo, mask uint32) error {
+	if entry.Attributes == nil {
+		return nil
+	}
+
+	if darwinIsSuperUser {
+		mask |= ^uint32(unix.UF_SETTABLE | unix.SF_SETTABLE)
+	} else {
+		mask |= ^uint32(unix.UF_SETTABLE)
+	}
+
+	var flags uint32
+
+	stat := fileInfo.Sys().(*syscall.Stat_t)
+	if stat == nil {
+		return errors.New("file stat info missing")
+	}
+	if v, have := (*entry.Attributes)[darwinFileFlagsKey]; have {
+		flags = binary.LittleEndian.Uint32(v)
+	}
+
+	flags = (flags & ^mask) | (stat.Flags & mask)
+
+	if flags != stat.Flags {
+		f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.O_SYMLINK, 0)
+		if err != nil {
+			return err
+		}
+		err = syscall.Fchflags(int(f.Fd()), int(flags))
 		f.Close()
 		return err
 	}

src/duplicacy_utils_linux.go

@@ -7,8 +7,9 @@ package duplicacy
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
+	"fmt"
 	"os"
-	"path/filepath"
 	"syscall"
 	"unsafe"
 
@@ -51,125 +52,55 @@ func ioctl(f *os.File, request uintptr, attrp *uint32) error {
 	return nil
 }
 
-type xattrHandle struct {
-	f        *os.File
-	fullPath string
+func excludedByAttribute(attributes map[string][]byte) bool {
+	_, excluded := attributes["user.duplicacy_exclude"]
+	if !excluded {
+		flags, ok := attributes[linuxFileFlagsKey]
+		excluded = ok && (binary.LittleEndian.Uint32(flags)&linux_FS_NODUMP_FL) != 0
+	}
+	return excluded
 }
 
-func (x xattrHandle) list() ([]string, error) {
-	if x.f != nil {
-		return xattr.FList(x.f)
-	} else {
-		return xattr.LList(x.fullPath)
-	}
-}
-
-func (x xattrHandle) get(name string) ([]byte, error) {
-	if x.f != nil {
-		return xattr.FGet(x.f, name)
-	} else {
-		return xattr.LGet(x.fullPath, name)
-	}
-}
-
-func (x xattrHandle) set(name string, value []byte) error {
-	if x.f != nil {
-		return xattr.FSet(x.f, name, value)
-	} else {
-		return xattr.LSet(x.fullPath, name, value)
-	}
-}
-
-func (x xattrHandle) remove(name string) error {
-	if x.f != nil {
-		return xattr.FRemove(x.f, name)
-	} else {
-		return xattr.LRemove(x.fullPath, name)
-	}
-}
-
-func (entry *Entry) ReadAttributes(top string) {
-	fullPath := filepath.Join(top, entry.Path)
-	x := xattrHandle{nil, fullPath}
-
-	if !entry.IsLink() {
-		var err error
-		x.f, err = os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW|syscall.O_NONBLOCK, 0)
+func (entry *Entry) ReadAttributes(fullPath string, fi os.FileInfo) error {
+	attributes, err := xattr.LList(fullPath)
 	if err != nil {
-			// FIXME: We really should return errors for failure to read
-			return
+		return err
 	}
-	}
-
-	attributes, _ := x.list()
 
 	if len(attributes) > 0 {
 		entry.Attributes = &map[string][]byte{}
 	}
+	var allErrors error
 	for _, name := range attributes {
-		attribute, err := x.get(name)
-		if err == nil {
-			(*entry.Attributes)[name] = attribute
-		}
-	}
-
-	if entry.IsFile() || entry.IsDir() {
-		if err := entry.readFileFlags(x.f); err != nil {
-			LOG_INFO("ATTR_BACKUP", "Could not backup flags for file %s: %v", fullPath, err)
-		}
-	}
-	x.f.Close()
-}
-
-func excludedByAttribute(attributes map[string][]byte) bool {
-	_, ok := attributes["user.duplicacy_exclude"]
-	return ok
-}
-
-func (entry *Entry) SetAttributesToFile(fullPath string) {
-	x := xattrHandle{nil, fullPath}
-	if !entry.IsLink() {
-		var err error
-		x.f, err = os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW, 0)
+		value, err := xattr.LGet(fullPath, name)
 		if err != nil {
-			return
-		}
-	}
-
-	names, _ := x.list()
-
-	for _, name := range names {
-		newAttribute, found := (*entry.Attributes)[name]
-		if found {
-			oldAttribute, _ := x.get(name)
-			if !bytes.Equal(oldAttribute, newAttribute) {
-				x.set(name, newAttribute)
-			}
-			delete(*entry.Attributes, name)
+			allErrors = errors.Join(allErrors, err)
 		} else {
-			x.remove(name)
+			(*entry.Attributes)[name] = value
 		}
 	}
 
-	for name, attribute := range *entry.Attributes {
-		if len(name) > 0 && name[0] == '\x00' {
-			continue
-		}
-		x.set(name, attribute)
-	}
-	if entry.IsFile() || entry.IsDir() {
-		if err := entry.restoreLateFileFlags(x.f); err != nil {
-			LOG_DEBUG("ATTR_RESTORE", "Could not restore flags for file %s: %v", fullPath, err)
-		}
-	}
-	x.f.Close()
+	return allErrors
 }
 
-func (entry *Entry) readFileFlags(f *os.File) error {
-	var flags uint32
-	if err := ioctl(f, linux_FS_IOC_GETFLAGS, &flags); err != nil {
+func (entry *Entry) ReadFileFlags(fullPath string, fileInfo os.FileInfo) error {
+	if !(entry.IsFile() || entry.IsDir()) {
+		return nil
+	}
+
+	f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW, 0)
+	if err != nil {
 		return err
 	}
+
+	var flags uint32
+
+	err = ioctl(f, linux_FS_IOC_GETFLAGS, &flags)
+	f.Close()
+	if err != nil {
+		return err
+	}
+
 	if flags != 0 {
 		if entry.Attributes == nil {
 			entry.Attributes = &map[string][]byte{}
@@ -177,49 +108,109 @@ func (entry *Entry) readFileFlags(f *os.File) error {
 		v := make([]byte, 4)
 		binary.LittleEndian.PutUint32(v, flags)
 		(*entry.Attributes)[linuxFileFlagsKey] = v
-		LOG_DEBUG("ATTR_READ", "Read flags 0x%x for %s", flags, entry.Path)
 	}
 	return nil
 }
 
-func (entry *Entry) RestoreEarlyDirFlags(path string) error {
-	if entry.Attributes == nil {
+func (entry *Entry) SetAttributesToFile(fullPath string) error {
+	if entry.Attributes == nil || len(*entry.Attributes) == 0 {
 		return nil
 	}
-	if v, have := (*entry.Attributes)[linuxFileFlagsKey]; have {
-		flags := binary.LittleEndian.Uint32(v) & linuxIocFlagsDirEarly
-		f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_DIRECTORY, 0)
+	attributes := *entry.Attributes
+
+	if _, haveFlags := attributes[linuxFileFlagsKey]; haveFlags && len(attributes) <= 1 {
+		return nil
+	}
+
+	names, err := xattr.LList(fullPath)
 	if err != nil {
 		return err
 	}
-		LOG_DEBUG("ATTR_RESTORE", "Restore dir flags (early) 0x%x for %s", flags, entry.Path)
-		err = ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
-		f.Close()
+	for _, name := range names {
+		newAttribute, found := (*entry.Attributes)[name]
+		if found {
+			oldAttribute, _ := xattr.LGet(fullPath, name)
+			if !bytes.Equal(oldAttribute, newAttribute) {
+				err = errors.Join(err, xattr.LSet(fullPath, name, newAttribute))
+			}
+			delete(*entry.Attributes, name)
+		} else {
+			err = errors.Join(err, xattr.LRemove(fullPath, name))
+		}
+	}
+
+	for name, attribute := range *entry.Attributes {
+		if len(name) > 0 && name[0] == '\x00' {
+			continue
+		}
+		err = errors.Join(err, xattr.LSet(fullPath, name, attribute))
+	}
 	return err
 }
-	return nil
-}
 
-func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
+func (entry *Entry) RestoreEarlyDirFlags(fullPath string, mask uint32) error {
 	if entry.Attributes == nil {
 		return nil
 	}
+	var flags uint32
+
 	if v, have := (*entry.Attributes)[linuxFileFlagsKey]; have {
-		flags := binary.LittleEndian.Uint32(v) & linuxIocFlagsFileEarly
-		LOG_DEBUG("ATTR_RESTORE", "Restore flags (early) 0x%x for %s", flags, entry.Path)
-		return ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		flags = binary.LittleEndian.Uint32(v) & linuxIocFlagsDirEarly & ^mask
+	}
+
+	if flags != 0 {
+		f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.O_DIRECTORY, 0)
+		if err != nil {
+			return err
+		}
+		err = ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		f.Close()
+		if err != nil {
+			return fmt.Errorf("Set flags 0x%.8x failed: %w", flags, err)
+		}
 	}
 	return nil
 }
 
-func (entry *Entry) restoreLateFileFlags(f *os.File) error {
+func (entry *Entry) RestoreEarlyFileFlags(f *os.File, mask uint32) error {
 	if entry.Attributes == nil {
 		return nil
 	}
+	var flags uint32
+
 	if v, have := (*entry.Attributes)[linuxFileFlagsKey]; have {
-		flags := binary.LittleEndian.Uint32(v) & (linuxIocFlagsFileEarly | linuxIocFlagsDirEarly | linuxIocFlagsLate)
-		LOG_DEBUG("ATTR_RESTORE", "Restore flags (late) 0x%x for %s", flags, entry.Path)
-		return ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		flags = binary.LittleEndian.Uint32(v) & linuxIocFlagsFileEarly & ^mask
+	}
+
+	if flags != 0 {
+		err := ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		if err != nil {
+			return fmt.Errorf("Set flags 0x%.8x failed: %w", flags, err)
+		}
+	}
+	return nil
+}
+
+func (entry *Entry) RestoreLateFileFlags(fullPath string, fileInfo os.FileInfo, mask uint32) error {
+	if entry.IsLink() || entry.Attributes == nil {
+		return nil
+	}
+	var flags uint32
+
+	if v, have := (*entry.Attributes)[linuxFileFlagsKey]; have {
+		flags = binary.LittleEndian.Uint32(v) & (linuxIocFlagsFileEarly | linuxIocFlagsDirEarly | linuxIocFlagsLate) & ^mask
+	}
+
+	if flags != 0 {
+		f, err := os.OpenFile(fullPath, os.O_RDONLY|syscall.O_NOFOLLOW, 0)
+		if err != nil {
+			return err
+		}
+		err = ioctl(f, linux_FS_IOC_SETFLAGS, &flags)
+		f.Close()
+		if err != nil {
+			return fmt.Errorf("Set flags 0x%.8x failed: %w", flags, err)
+		}
 	}
 	return nil
 }

src/duplicacy_utils_others.go

@@ -8,6 +8,7 @@
 package duplicacy
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path"
@@ -57,7 +58,7 @@ func (entry *Entry) getHardLinkKey(f os.FileInfo) (key listEntryLinkKey, linked
 		return
 	}
 	stat := f.Sys().(*syscall.Stat_t)
-	if stat == nil || stat.Nlink < 2 {
+	if stat == nil || stat.Nlink <= 1 {
 		return
 	}
 	key.dev = uint64(stat.Dev)
@@ -66,19 +67,19 @@ func (entry *Entry) getHardLinkKey(f os.FileInfo) (key listEntryLinkKey, linked
 	return
 }
 
-func (entry *Entry) ReadSpecial(fileInfo os.FileInfo) bool {
+func (entry *Entry) ReadSpecial(fullPath string, fileInfo os.FileInfo) error {
 	if fileInfo.Mode()&(os.ModeDevice|os.ModeCharDevice) == 0 {
-		return true
+		return nil
 	}
 	stat := fileInfo.Sys().(*syscall.Stat_t)
 	if stat == nil {
-		return false
+		return errors.New("file stat info missing")
 	}
 	entry.Size = 0
 	rdev := uint64(stat.Rdev)
 	entry.StartChunk = int(rdev & 0xFFFFFFFF)
 	entry.StartOffset = int(rdev >> 32)
-	return true
+	return nil
 }
 
 func (entry *Entry) GetRdev() uint64 {

src/duplicacy_utils_windows.go

@@ -116,15 +116,32 @@ func (entry *Entry) getHardLinkKey(f os.FileInfo) (key listEntryLinkKey, linked
 	return
 }
 
-func (entry *Entry) ReadAttributes(top string) {
+func (entry *Entry) ReadAttributes(fullPath string, fi os.FileInfo) error {
+	return nil
 }
 
-func (entry *Entry) SetAttributesToFile(fullPath string) {
-
+func (entry *Entry) ReadFileFlags(fullPath string, fileInfo os.FileInfo) error {
+	return nil
 }
 
-func (entry *Entry) ReadSpecial(fileInfo os.FileInfo) bool {
-	return true
+func (entry *Entry) SetAttributesToFile(fullPath string) error {
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyDirFlags(fullPath string, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyFileFlags(f *os.File, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreLateFileFlags(fullPath string, fileInfo os.FileInfo, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) ReadSpecial(fullPath string, fileInfo os.FileInfo) error {
+	return nil
 }
 
 func (entry *Entry) IsSameSpecial(fileInfo os.FileInfo) bool {
@@ -161,11 +178,3 @@ func SplitDir(fullPath string) (dir string, file string) {
 func excludedByAttribute(attributes map[string][]byte) bool {
 	return false
 }
-
-func (entry *Entry) RestoreEarlyDirFlags(path string) error {
-	return nil
-}
-
-func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
-	return nil
-}

src/duplicacy_utils_xbsd.go

@@ -10,110 +10,148 @@ package duplicacy
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
 	"os"
-	"path/filepath"
 	"syscall"
 	"unsafe"
 
 	"github.com/pkg/xattr"
 )
 
-const bsd_UF_NODUMP = 0x1
+const (
+	bsd_UF_NODUMP   = 0x1
+	bsd_SF_SETTABLE = 0xffff0000
+	bsd_UF_SETTABLE = 0x0000ffff
 
-const bsdFileFlagsKey = "\x00bf"
+	bsdFileFlagsKey = "\x00bf"
+)
+
+var bsdIsSuperUser bool
+
+func init() {
+	bsdIsSuperUser = syscall.Geteuid() == 0
+}
 
 func excludedByAttribute(attributes map[string][]byte) bool {
 	_, excluded := attributes["duplicacy_exclude"]
 	if !excluded {
-		value, ok := attributes[bsdFileFlagsKey]
-		excluded = ok && (binary.LittleEndian.Uint32(value) & bsd_UF_NODUMP) != 0
+		flags, ok := attributes[bsdFileFlagsKey]
+		excluded = ok && (binary.LittleEndian.Uint32(flags)&bsd_UF_NODUMP) != 0
 	}
 	return excluded
 }
 
-func (entry *Entry) ReadAttributes(top string) {
-	fullPath := filepath.Join(top, entry.Path)
-	fileInfo, err := os.Lstat(fullPath)
-	if err != nil {
-		return
+func (entry *Entry) ReadAttributes(fullPath string, fi os.FileInfo) error {
+	if entry.IsSpecial() {
+		return nil
 	}
 
-	if !entry.IsSpecial() {
-		attributes, _ := xattr.LList(fullPath)
+	attributes, err := xattr.LList(fullPath)
+	if err != nil {
+		return err
+	}
 
 	if len(attributes) > 0 {
 		entry.Attributes = &map[string][]byte{}
+	}
+	var allErrors error
 	for _, name := range attributes {
-				attribute, err := xattr.LGet(fullPath, name)
-				if err == nil {
-					(*entry.Attributes)[name] = attribute
-				}
-			}
-		}
-	}
-	if err := entry.readFileFlags(fileInfo); err != nil {
-		LOG_INFO("ATTR_BACKUP", "Could not backup flags for file %s: %v", fullPath, err)
-	}
-}
-
-func (entry *Entry) SetAttributesToFile(fullPath string) {
-	if !entry.IsSpecial() {
-		names, _ := xattr.LList(fullPath)
-		for _, name := range names {
-			newAttribute, found := (*entry.Attributes)[name]
-			if found {
-				oldAttribute, _ := xattr.LGet(fullPath, name)
-				if !bytes.Equal(oldAttribute, newAttribute) {
-					xattr.LSet(fullPath, name, newAttribute)
-				}
-				delete(*entry.Attributes, name)
+		value, err := xattr.LGet(fullPath, name)
+		if err != nil {
+			allErrors = errors.Join(allErrors, err)
 		} else {
-				xattr.LRemove(fullPath, name)
+			(*entry.Attributes)[name] = value
 		}
 	}
 
-		for name, attribute := range *entry.Attributes {
-			if len(name) > 0 && name[0] == '\x00' {
-				continue
-			}
-			xattr.LSet(fullPath, name, attribute)
-		}
-	}
-	if err := entry.restoreLateFileFlags(fullPath); err != nil {
-		LOG_DEBUG("ATTR_RESTORE", "Could not restore flags for file %s: %v", fullPath, err)
-	}
+	return allErrors
 }
 
-func (entry *Entry) RestoreEarlyDirFlags(path string) error {
-	return nil
-}
-
-func (entry *Entry) RestoreEarlyFileFlags(f *os.File) error {
-	return nil
-}
-
-func (entry *Entry) readFileFlags(fileInfo os.FileInfo) error {
-	stat, ok := fileInfo.Sys().(*syscall.Stat_t)
-	if ok && stat.Flags != 0 {
+func (entry *Entry) ReadFileFlags(fullPath string, fileInfo os.FileInfo) error {
+	stat, _ := fileInfo.Sys().(*syscall.Stat_t)
+	if stat != nil && stat.Flags != 0 {
 		if entry.Attributes == nil {
 			entry.Attributes = &map[string][]byte{}
 		}
 		v := make([]byte, 4)
 		binary.LittleEndian.PutUint32(v, stat.Flags)
 		(*entry.Attributes)[bsdFileFlagsKey] = v
-		LOG_DEBUG("ATTR_READ", "Read flags 0x%x for %s", stat.Flags, entry.Path)
 	}
 	return nil
 }
 
-func (entry *Entry) restoreLateFileFlags(path string) error {
+func (entry *Entry) SetAttributesToFile(fullPath string) error {
+	if entry.Attributes == nil || len(*entry.Attributes) == 0 || entry.IsSpecial() {
+		return nil
+	}
+	attributes := *entry.Attributes
+
+	if _, haveFlags := attributes[bsdFileFlagsKey]; haveFlags && len(attributes) <= 1 {
+		return nil
+	}
+
+	names, err := xattr.LList(fullPath)
+	if err != nil {
+		return err
+	}
+	for _, name := range names {
+		newAttribute, found := attributes[name]
+		if found {
+			oldAttribute, _ := xattr.LGet(fullPath, name)
+			if !bytes.Equal(oldAttribute, newAttribute) {
+				err = errors.Join(err, xattr.LSet(fullPath, name, newAttribute))
+			}
+			delete(attributes, name)
+		} else {
+			err = errors.Join(err, xattr.LRemove(fullPath, name))
+		}
+	}
+
+	for name, attribute := range attributes {
+		if len(name) > 0 && name[0] == '\x00' {
+			continue
+		}
+		err = errors.Join(err, xattr.LSet(fullPath, name, attribute))
+	}
+	return err
+}
+
+func (entry *Entry) RestoreEarlyDirFlags(fullPath string, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreEarlyFileFlags(f *os.File, mask uint32) error {
+	return nil
+}
+
+func (entry *Entry) RestoreLateFileFlags(fullPath string, fileInfo os.FileInfo, mask uint32) error {
 	if entry.Attributes == nil {
 		return nil
 	}
+
+	if bsdIsSuperUser {
+		mask |= ^uint32(bsd_UF_SETTABLE | bsd_SF_SETTABLE)
+	} else {
+		mask |= ^uint32(bsd_UF_SETTABLE)
+	}
+
+	var flags uint32
+
+	stat := fileInfo.Sys().(*syscall.Stat_t)
+	if stat == nil {
+		return errors.New("file stat info missing")
+	}
 	if v, have := (*entry.Attributes)[bsdFileFlagsKey]; have {
+		flags = binary.LittleEndian.Uint32(v)
+	}
+
+	flags = (flags & ^mask) | (stat.Flags & mask)
+
+	if flags != stat.Flags {
+		pPath, _ := syscall.BytePtrFromString(fullPath)
 		if _, _, errno := syscall.Syscall(syscall.SYS_LCHFLAGS,
-			uintptr(unsafe.Pointer(syscall.StringBytePtr(path))),
-			uintptr(binary.LittleEndian.Uint32((v))), 0); errno != 0 {
+			uintptr(unsafe.Pointer(pPath)),
+			uintptr(flags), 0); errno != 0 {
 			return os.NewSyscallError("lchflags", errno)
 		}
 	}