This helps implementing is_allocated on top of get_block_status.
Reviewed-by: Eric Blake <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
---
block.c | 5 +++++
qemu-img.c | 9 +--------
2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/block.c b/block.c
index a3f7577..e18ff71 100644
--- a/block.c
+++ b/block.c
@@ -3011,6 +3011,11 @@ int bdrv_has_zero_init(BlockDriverState *bs)
{
assert(bs->drv);
+ /* If BS is a copy on write image, it is initialized to
+ the contents of the base image, which may not be zeroes. */
+ if (bs->backing_hd) {
+ return 0;
+ }
if (bs->drv->bdrv_has_zero_init) {
return bs->drv->bdrv_has_zero_init(bs);
}
diff --git a/qemu-img.c b/qemu-img.c
index 837f8bc..d50e0fc 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1514,14 +1514,7 @@ static int img_convert(int argc, char **argv)
should add a specific call to have the info to go faster */
buf1 = buf;
while (n > 0) {
- /* If the output image is being created as a copy on write
image,
- copy all sectors even the ones containing only NUL bytes,
- because they may differ from the sectors in the base image.
-
- If the output is to a host device, we also write out
- sectors that are entirely 0, since whatever data was
- already there is garbage, not 0s. */
- if (!has_zero_init || out_baseimg ||
+ if (!has_zero_init ||
is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
ret = bdrv_write(out_bs, sector_num, buf1, n1);
if (ret < 0) {
--
1.8.3.1
