block: add wrappers for logical block provisioning information

This adds 2 wrappers to read the unallocated_blocks_are_zero and
can_write_zeroes_with_unmap info from the BDI. The wrappers are
required to check for the existence of a backing_hd and
if the devices are opened with the correct flags.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Peter Lieven 2013-10-24 12:06:54 +02:00 committed by Kevin Wolf
parent e1a5c4bed4
commit 4ce786914b
2 changed files with 32 additions and 0 deletions

30
block.c
View File

@ -3103,6 +3103,36 @@ int bdrv_has_zero_init(BlockDriverState *bs)
return 0;
}
bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
{
BlockDriverInfo bdi;
if (bs->backing_hd) {
return false;
}
if (bdrv_get_info(bs, &bdi) == 0) {
return bdi.unallocated_blocks_are_zero;
}
return false;
}
bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
{
BlockDriverInfo bdi;
if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) {
return false;
}
if (bdrv_get_info(bs, &bdi) == 0) {
return bdi.can_write_zeroes_with_unmap;
}
return false;
}
typedef struct BdrvCoGetBlockStatusData {
BlockDriverState *bs;
BlockDriverState *base;

View File

@ -344,6 +344,8 @@ int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
int bdrv_has_zero_init_1(BlockDriverState *bs);
int bdrv_has_zero_init(BlockDriverState *bs);
bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum);
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,