On 16.07.2013 18:29, Paolo Bonzini wrote:
Define the return value of get_block_status. Bits 0, 1, 2 and 9-62 are valid; bit 63 (the sign bit) is reserved for errors. Bits 3-7 are left for future extensions.The return code is compatible with the old is_allocated API: returning just 0 or 1 (aka BDRV_BLOCK_DATA) will not cause any behavioral change in clients of is_allocated. We will return more precise information in the next patches. Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- v1->v2: improved comment block.c | 7 +++++-- include/block/block.h | 26 ++++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 2 deletions(-) diff --git a/block.c b/block.c index 6e7a8a3..7ff0716 100644 --- a/block.c +++ b/block.c @@ -2990,7 +2990,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,if (!bs->drv->bdrv_co_get_block_status) {*pnum = nb_sectors; - return 1; + return BDRV_BLOCK_DATA; }return bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum);@@ -3040,7 +3040,10 @@ int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num, int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum) { - return bdrv_get_block_status(bs, sector_num, nb_sectors, pnum); + int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum); + return + (ret & BDRV_BLOCK_DATA) || + ((ret & BDRV_BLOCK_ZERO) && !bdrv_has_zero_init(bs));
i do also not understand the "((ret & BDRV_BLOCK_ZERO) && !bdrv_has_zero_init(bs))"; if a block is unallocated and reads as zero, but the device lacks zero init, it is declared as allocated with this, isn't it? for iscsi and host_device with lbprz==1 or discardzeroes respectively all blocks would return as allocated. is this wanted? Peter
