Unallocated sectors should really never be accessed by the guest,
so there's no need to copy them during the streaming process.
If they are read by the guest during streaming, guest-initiated
copy-on-read will copy them (we're in the base == NULL case, which
enables copy on read). If they are read after we disconnect the
image from the base, they will read as zeroes anyway.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
block/stream.c | 18 ++++--------------
tests/qemu-iotests/030 | 5 +++--
2 files changed, 7 insertions(+), 16 deletions(-)
diff --git a/block/stream.c b/block/stream.c
index b76104c..f9766db 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -130,14 +130,9 @@ static int coroutine_fn is_allocated_base(BlockDriverState
*top,
*/
intermediate = top->backing_hd;
- while (intermediate) {
+ while (intermediate != base) {
int pnum_inter;
- /* reached base */
- if (intermediate == base) {
- *pnum = n;
- return 1;
- }
ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors,
&pnum_inter);
if (ret < 0) {
@@ -160,6 +155,7 @@ static int coroutine_fn is_allocated_base(BlockDriverState
*top,
intermediate = intermediate->backing_hd;
}
+ *pnum = n;
return 1;
}
@@ -198,14 +194,8 @@ retry:
}
s->common.busy = true;
- if (base) {
- ret = is_allocated_base(bs, base, sector_num,
- STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
- } else {
- ret = bdrv_co_is_allocated(bs, sector_num,
- STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE,
- &n);
- }
+ ret = is_allocated_base(bs, base, sector_num,
+ STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n);
trace_stream_one_iteration(s, sector_num, n, ret);
if (ret == 0) {
if (s->common.speed) {
diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index 9c74dd2..9ab5c1c 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -67,8 +67,9 @@ class TestSingleDrive(ImageStreamingTestCase):
self.assert_no_active_streams()
self.vm.shutdown()
- self.assertFalse('sectors not allocated' in qemu_io('-c', 'map',
test_img),
- 'image file not fully populated after streaming')
+ self.assertEqual(qemu_io('-c', 'map', backing_img),
+ qemu_io('-c', 'map', test_img),
+ 'image file map does not match backing file after
streaming')
def test_stream_partial(self):
self.assert_no_active_streams()
--
1.7.9.3
