qemu-iotests: Test qcow2 not leaking clusters on write error

This adds a test for a temporary write failure, which simulates the
situation after werror=stop/enospc has stopped the VM. We shouldn't
leave leaked clusters behind in such cases.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/qemu-iotests/026 b/tests/qemu-iotests/026
index 7fadfba..582d254 100755
--- a/tests/qemu-iotests/026
+++ b/tests/qemu-iotests/026
@@ -200,6 +200,23 @@ done
 done
 done
 
+echo
+echo === Avoid cluster leaks after temporary failure ===
+echo
+
+cat > "$TEST_DIR/blkdebug.conf" <<EOF
+[inject-error]
+event = "write_aio"
+errno = "5"
+once = "on"
+EOF
+
+# After the failed first write, do a second write so that the updated refcount
+# block is actually written back
+_make_test_img 64M
+$QEMU_IO -c "write 0 1M" -c "write 0 1M" "$BLKDBG_TEST_IMG" | _filter_qemu_io
+_check_test_img
+
 # success, all done
 echo "*** done"
 rm -f $seq.full