fs: add WithAllowXAttrErrors CopyOpt

fs/copy.go

@@ -32,14 +32,49 @@ var bufferPool = &sync.Pool{
 	},
 }
 
+// XAttrErrorHandlers transform a non-nil xattr error.
+// Return nil to ignore an error.
+// xattrKey can be empty for listxattr operation.
+type XAttrErrorHandler func(dst, src, xattrKey string, err error) error
+
+type copyDirOpts struct {
+	xeh XAttrErrorHandler
+}
+
+type CopyDirOpt func(*copyDirOpts) error
+
+// WithXAttrErrorHandler allows specifying XAttrErrorHandler
+// If nil XAttrErrorHandler is specified (default), CopyDir stops
+// on a non-nil xattr error.
+func WithXAttrErrorHandler(xeh XAttrErrorHandler) CopyDirOpt {
+	return func(o *copyDirOpts) error {
+		o.xeh = xeh
+		return nil
+	}
+}
+
+// WithAllowXAttrErrors allows ignoring xattr errors.
+func WithAllowXAttrErrors() CopyDirOpt {
+	xeh := func(dst, src, xattrKey string, err error) error {
+		return nil
+	}
+	return WithXAttrErrorHandler(xeh)
+}
+
 // CopyDir copies the directory from src to dst.
 // Most efficient copy of files is attempted.
-func CopyDir(dst, src string) error {
+func CopyDir(dst, src string, opts ...CopyDirOpt) error {
+	var o copyDirOpts
+	for _, opt := range opts {
+		if err := opt(&o); err != nil {
+			return err
+		}
+	}
 	inodes := map[uint64]string{}
-	return copyDirectory(dst, src, inodes)
+	return copyDirectory(dst, src, inodes, &o)
 }
 
-func copyDirectory(dst, src string, inodes map[uint64]string) error {
+func copyDirectory(dst, src string, inodes map[uint64]string, o *copyDirOpts) error {
 	stat, err := os.Stat(src)
 	if err != nil {
 		return errors.Wrapf(err, "failed to stat %s", src)
@@ -75,7 +110,7 @@ func copyDirectory(dst, src string, inodes map[uint64]string) error {
 
 		switch {
 		case fi.IsDir():
-			if err := copyDirectory(target, source, inodes); err != nil {
+			if err := copyDirectory(target, source, inodes, o); err != nil {
 				return err
 			}
 			continue
@@ -111,7 +146,7 @@ func copyDirectory(dst, src string, inodes map[uint64]string) error {
 			return errors.Wrap(err, "failed to copy file info")
 		}
 
-		if err := copyXAttrs(target, source); err != nil {
+		if err := copyXAttrs(target, source, o.xeh); err != nil {
 			return errors.Wrap(err, "failed to copy xattrs")
 		}
 	}

fs/copy_linux.go

@@ -73,9 +73,9 @@ func copyFileContent(dst, src *os.File) error {
 	dstFd := int(dst.Fd())
 
 	for size > 0 {
-        // Ensure that we are never trying to copy more than SSIZE_MAX at a
-        // time and at the same time avoids overflows when the file is larger
-        // than 4GB on 32-bit systems.
+		// Ensure that we are never trying to copy more than SSIZE_MAX at a
+		// time and at the same time avoids overflows when the file is larger
+		// than 4GB on 32-bit systems.
 		var copySize int
 		if size > maxSSizeT {
 			copySize = int(maxSSizeT)
@@ -101,18 +101,34 @@ func copyFileContent(dst, src *os.File) error {
 	return nil
 }
 
-func copyXAttrs(dst, src string) error {
+func copyXAttrs(dst, src string, xeh XAttrErrorHandler) error {
 	xattrKeys, err := sysx.LListxattr(src)
 	if err != nil {
-		return errors.Wrapf(err, "failed to list xattrs on %s", src)
+		e := errors.Wrapf(err, "failed to list xattrs on %s", src)
+		if xeh != nil {
+			e = xeh(dst, src, "", e)
+		}
+		return e
 	}
 	for _, xattr := range xattrKeys {
 		data, err := sysx.LGetxattr(src, xattr)
 		if err != nil {
-			return errors.Wrapf(err, "failed to get xattr %q on %s", xattr, src)
+			e := errors.Wrapf(err, "failed to get xattr %q on %s", xattr, src)
+			if xeh != nil {
+				if e = xeh(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
 		}
 		if err := sysx.LSetxattr(dst, xattr, data, 0); err != nil {
-			return errors.Wrapf(err, "failed to set xattr %q on %s", xattr, dst)
+			e := errors.Wrapf(err, "failed to set xattr %q on %s", xattr, dst)
+			if xeh != nil {
+				if e = xeh(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
 		}
 	}
 

fs/copy_unix.go

@@ -69,18 +69,34 @@ func copyFileContent(dst, src *os.File) error {
 	return err
 }
 
-func copyXAttrs(dst, src string) error {
+func copyXAttrs(dst, src string, xeh XAttrErrorHandler) error {
 	xattrKeys, err := sysx.LListxattr(src)
 	if err != nil {
-		return errors.Wrapf(err, "failed to list xattrs on %s", src)
+		e := errors.Wrapf(err, "failed to list xattrs on %s", src)
+		if xeh != nil {
+			e = xeh(dst, src, "", e)
+		}
+		return e
 	}
 	for _, xattr := range xattrKeys {
 		data, err := sysx.LGetxattr(src, xattr)
 		if err != nil {
-			return errors.Wrapf(err, "failed to get xattr %q on %s", xattr, src)
+			e := errors.Wrapf(err, "failed to get xattr %q on %s", xattr, src)
+			if xeh != nil {
+				if e = xeh(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
 		}
 		if err := sysx.LSetxattr(dst, xattr, data, 0); err != nil {
-			return errors.Wrapf(err, "failed to set xattr %q on %s", xattr, dst)
+			e := errors.Wrapf(err, "failed to set xattr %q on %s", xattr, dst)
+			if xeh != nil {
+				if e = xeh(dst, src, xattr, e); e == nil {
+					continue
+				}
+			}
+			return e
 		}
 	}
 

fs/copy_windows.go

@@ -40,7 +40,7 @@ func copyFileContent(dst, src *os.File) error {
 	return err
 }
 
-func copyXAttrs(dst, src string) error {
+func copyXAttrs(dst, src string, xeh XAttrErrorHandler) error {
 	return nil
 }