diff --git a/olivefs/src/filesystem.rs b/olivefs/src/filesystem.rs
index 1583fa1..dbda5bb 100644
--- a/olivefs/src/filesystem.rs
+++ b/olivefs/src/filesystem.rs
@@ -1099,6 +1099,8 @@ impl Filesystem for OliveFilesystem {
     }
 
     /// Reposition read/write file offset
+    /// used for looking for holes (for sparse files e.g. with cp and tar)
+    /// whence: SEEK_HOLE or SEEK_DATA.
     fn lseek(
         &mut self,
         _req: &Request<'_>,