block: make bdrv_has_zero_init return false for copy-on-write-images
This helps implementing is_allocated on top of get_block_status. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
parent
e4a86f88cc
commit
11212d8fa0
5
block.c
5
block.c
|
@ -3031,6 +3031,11 @@ int bdrv_has_zero_init(BlockDriverState *bs)
|
||||||
{
|
{
|
||||||
assert(bs->drv);
|
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) {
|
if (bs->drv->bdrv_has_zero_init) {
|
||||||
return bs->drv->bdrv_has_zero_init(bs);
|
return bs->drv->bdrv_has_zero_init(bs);
|
||||||
}
|
}
|
||||||
|
|
|
@ -1537,14 +1537,7 @@ static int img_convert(int argc, char **argv)
|
||||||
should add a specific call to have the info to go faster */
|
should add a specific call to have the info to go faster */
|
||||||
buf1 = buf;
|
buf1 = buf;
|
||||||
while (n > 0) {
|
while (n > 0) {
|
||||||
/* If the output image is being created as a copy on write image,
|
if (!has_zero_init ||
|
||||||
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 ||
|
|
||||||
is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
|
is_allocated_sectors_min(buf1, n, &n1, min_sparse)) {
|
||||||
ret = bdrv_write(out_bs, sector_num, buf1, n1);
|
ret = bdrv_write(out_bs, sector_num, buf1, n1);
|
||||||
if (ret < 0) {
|
if (ret < 0) {
|
||||||
|
|
Loading…
Reference in New Issue