Added VolumeMarkWritable and VolumeStatus grpc methods

This is necessary for copy to mark as read-only and then restore the
original state afterwards.

weed/storage/store.go

@@ -307,7 +307,20 @@ func (s *Store) MarkVolumeReadonly(i needle.VolumeId) error {
 	if v == nil {
 		return fmt.Errorf("volume %d not found", i)
 	}
+	v.noWriteLock.Lock()
 	v.noWriteOrDelete = true
+	v.noWriteLock.Unlock()
+	return nil
+}
+
+func (s *Store) MarkVolumeWritable(i needle.VolumeId) error {
+	v := s.findVolume(i)
+	if v == nil {
+		return fmt.Errorf("volume %d not found", i)
+	}
+	v.noWriteLock.Lock()
+	v.noWriteOrDelete = false
+	v.noWriteLock.Unlock()
 	return nil
 }
 

weed/storage/volume.go

@@ -27,6 +27,7 @@ type Volume struct {
 	needleMapKind      NeedleMapType
 	noWriteOrDelete    bool // if readonly, either noWriteOrDelete or noWriteCanDelete
 	noWriteCanDelete   bool // if readonly, either noWriteOrDelete or noWriteCanDelete
+	noWriteLock        sync.RWMutex
 	hasRemoteFile      bool // if the volume has a remote file
 	MemoryMapMaxSizeMb uint32
 
@@ -58,6 +59,8 @@ func NewVolume(dirname string, collection string, id needle.VolumeId, needleMapK
 }
 
 func (v *Volume) String() string {
+	v.noWriteLock.RLock()
+	defer v.noWriteLock.RUnlock()
 	return fmt.Sprintf("Id:%v, dir:%s, Collection:%s, dataFile:%v, nm:%v, noWrite:%v canDelete:%v", v.Id, v.dir, v.Collection, v.DataBackend, v.nm, v.noWriteOrDelete || v.noWriteCanDelete, v.noWriteCanDelete)
 }
 
@@ -245,5 +248,7 @@ func (v *Volume) RemoteStorageNameKey() (storageName, storageKey string) {
 }
 
 func (v *Volume) IsReadOnly() bool {
+	v.noWriteLock.RLock()
+	defer v.noWriteLock.RUnlock()
 	return v.noWriteOrDelete || v.noWriteCanDelete || v.location.isDiskSpaceLow
 }

weed/storage/volume_super_block.go

@@ -26,8 +26,10 @@ func (v *Volume) maybeWriteSuperBlock() error {
 			if dataFile, e = os.Create(v.DataBackend.Name()); e == nil {
 				v.DataBackend = backend.NewDiskFile(dataFile)
 				if _, e = v.DataBackend.WriteAt(v.SuperBlock.Bytes(), 0); e == nil {
+					v.noWriteLock.Lock()
 					v.noWriteOrDelete = false
 					v.noWriteCanDelete = false
+					v.noWriteLock.Unlock()
 				}
 			}
 		}