From 554562fef24d49cfab2dccee5e163c8da5bb5e7d Mon Sep 17 00:00:00 2001
From: Anatol Belski <anbelski@linux.microsoft.com>
Date: Thu, 12 Mar 2026 21:06:48 +0100
Subject: [PATCH] block: qcow_sync: impl SparseCapable for QcowDiskSync

Advertise support for sparse operations and the zero flag. QCOW2
inherently supports both through cluster deallocation.

Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
---
 block/src/qcow_sync.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/block/src/qcow_sync.rs b/block/src/qcow_sync.rs
index 56c19307f..c75e895e8 100644
--- a/block/src/qcow_sync.rs
+++ b/block/src/qcow_sync.rs
@@ -298,6 +298,16 @@ impl disk_file::DiskFd for QcowDiskSync {
 
 impl disk_file::Geometry for QcowDiskSync {}
 
+impl disk_file::SparseCapable for QcowDiskSync {
+    fn supports_sparse_operations(&self) -> bool {
+        true
+    }
+
+    fn supports_zero_flag(&self) -> bool {
+        true
+    }
+}
+
 pub struct QcowSync {
     metadata: Arc<QcowMetadata>,
     data_file: QcowRawFile,