+// Save modifications to the indicated collection in srcfs, then (if
+// successful) ensure they are also reflected in dstfs.
+func (h *handler) syncCollection(srcfs, dstfs arvados.CustomFileSystem, path string) error {
+ coll, _ := h.determineCollection(srcfs, path)
+ if coll == nil || coll.UUID == "" {
+ return errors.New("could not determine collection to sync")
+ }
+ d, err := srcfs.OpenFile("by_id/"+coll.UUID, os.O_RDWR, 0777)
+ if err != nil {
+ return err
+ }
+ defer d.Close()
+ err = d.Sync()
+ if err != nil {
+ return err
+ }
+ snap, err := d.Snapshot()
+ if err != nil {
+ return err
+ }
+ dstd, err := dstfs.OpenFile("by_id/"+coll.UUID, os.O_RDWR, 0777)
+ if err != nil {
+ return err
+ }
+ defer dstd.Close()
+ return dstd.Splice(snap)
+}
+