Am 02.10.2013 17:13, schrieb Paolo Bonzini: > Il 02/10/2013 17:06, Stefan Hajnoczi ha scritto: >> Sorry I didn't review this earlier but this flag looks hacky and I'm not >> confident about merging the patch yet. >> >> The patch makes me wonder if the raw_bsd driver should avoid calling >> bs->file itself: >> >> return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | >> (sector_num << BDRV_SECTOR_BITS); >> >> Let block.c:bdrv_co_get_block_status() call down into bs->file. >> >> The problem is then the protocol cannot report unallocated sectors with >> this approach. >> >> I think we want to preserve bs' offset while taking the other flags from >> bs->file (DATA, ZERO). > This would cause other changes. For example, a qcow2 with full metadata > preallocation (i.e. all L2 tables are there but it points to holes) > would not return DATA anymore. I think this is wrong, and especially a > change from the old is_allocated API. > > However, a variant on this idea could be to return > > BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | > (sector_num << BDRV_SECTOR_BITS); > > and then BDRV_BLOCK_RAW would mean "take DATA and ZERO from bs->file". Like this?
diff --git a/block.c b/block.c index 93e113a..71fab1f 100644 --- a/block.c +++ b/block.c @@ -3146,6 +3146,10 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, *pnum = 0; return ret; } + + if (ret & BDRV_BLOCK_RAW) { + return bdrv_get_block_status(bs->file, sector_num, nb_sectors, pnum); + } if (!(ret & BDRV_BLOCK_DATA)) { if (bdrv_has_zero_init(bs)) { diff --git a/block/raw_bsd.c b/block/raw_bsd.c index d4ace60..308d605 100644 --- a/block/raw_bsd.c +++ b/block/raw_bsd.c @@ -62,7 +62,8 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum) { - return bdrv_get_block_status(bs->file, sector_num, nb_sectors, pnum); + return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | + (sector_num << BDRV_SECTOR_BITS); }