rclone/backend/local/xattr.go

114 lines
2.6 KiB
Go

//go:build !openbsd && !plan9
package local
import (
"fmt"
"strings"
"syscall"
"github.com/pkg/xattr"
"github.com/rclone/rclone/fs"
)
const (
xattrPrefix = "user." // FIXME is this correct for all unixes?
xattrSupported = xattr.XATTR_SUPPORTED
)
// Check to see if the error supplied is a not supported error, and if
// so, disable xattrs
func (f *Fs) xattrIsNotSupported(err error) bool {
xattrErr, ok := err.(*xattr.Error)
if !ok {
return false
}
// Xattrs not supported can be ENOTSUP or ENOATTR or EINVAL (on Solaris)
if xattrErr.Err == syscall.EINVAL || xattrErr.Err == syscall.ENOTSUP || xattrErr.Err == xattr.ENOATTR {
// Show xattrs not supported
if f.xattrSupported.CompareAndSwap(1, 0) {
fs.Errorf(f, "xattrs not supported - disabling: %v", err)
}
return true
}
return false
}
// getXattr returns the extended attributes for an object
//
// It doesn't return any attributes owned by this backend in
// metadataKeys
func (o *Object) getXattr() (metadata fs.Metadata, err error) {
if !xattrSupported || o.fs.xattrSupported.Load() == 0 {
return nil, nil
}
var list []string
if o.fs.opt.FollowSymlinks {
list, err = xattr.List(o.path)
} else {
list, err = xattr.LList(o.path)
}
if err != nil {
if o.fs.xattrIsNotSupported(err) {
return nil, nil
}
return nil, fmt.Errorf("failed to read xattr: %w", err)
}
if len(list) == 0 {
return nil, nil
}
metadata = make(fs.Metadata, len(list))
for _, k := range list {
var v []byte
if o.fs.opt.FollowSymlinks {
v, err = xattr.Get(o.path, k)
} else {
v, err = xattr.LGet(o.path, k)
}
if err != nil {
if o.fs.xattrIsNotSupported(err) {
return nil, nil
}
return nil, fmt.Errorf("failed to read xattr key %q: %w", k, err)
}
k = strings.ToLower(k)
if !strings.HasPrefix(k, xattrPrefix) {
continue
}
k = k[len(xattrPrefix):]
if _, found := systemMetadataInfo[k]; found {
continue
}
metadata[k] = string(v)
}
return metadata, nil
}
// setXattr sets the metadata on the file Xattrs
//
// It doesn't set any attributes owned by this backend in metadataKeys
func (o *Object) setXattr(metadata fs.Metadata) (err error) {
if !xattrSupported || o.fs.xattrSupported.Load() == 0 {
return nil
}
for k, value := range metadata {
k = strings.ToLower(k)
if _, found := systemMetadataInfo[k]; found {
continue
}
k = xattrPrefix + k
v := []byte(value)
if o.fs.opt.FollowSymlinks {
err = xattr.Set(o.path, k, v)
} else {
err = xattr.LSet(o.path, k, v)
}
if err != nil {
if o.fs.xattrIsNotSupported(err) {
return nil
}
return fmt.Errorf("failed to set xattr key %q: %w", k, err)
}
}
return nil
}