demo/link_cp: don't issue 0 bytes IO ops

CarterLi · Aug 14, 2023 · b8eac66 · b8eac66
1 parent c0a7ed7
commit b8eac66
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/demo/link_cp.cpp b/demo/link_cp.cpp
@@ -42,8 +42,11 @@ uio::task<> copy_file(uio::io_service& service, off_t insize) {
     }
 
     int left = insize - offset;
-    service.read_fixed(0, buf.data(), left, offset, 0, IOSQE_FIXED_FILE | IOSQE_IO_LINK) | panic_on_err("read_fixed(2)", false);
-    service.write_fixed(1, buf.data(), left, offset, 0, IOSQE_FIXED_FILE) | panic_on_err("write_fixed(2)", false);
+    if (left)
+    {
+        service.read_fixed(0, buf.data(), left, offset, 0, IOSQE_FIXED_FILE | IOSQE_IO_LINK) | panic_on_err("read_fixed(2)", false);
+        service.write_fixed(1, buf.data(), left, offset, 0, IOSQE_FIXED_FILE | IOSQE_IO_LINK) | panic_on_err("write_fixed(2)", false);
+    }
     co_await service.fsync(1, 0, IOSQE_FIXED_FILE);
 }