Il 25/11/2013 14:57, Peter Lieven ha scritto: > this patch aims to set bdi->cluster_size to the internal page size > of the iscsi target so that enabled callers can align requests > properly. > > Signed-off-by: Peter Lieven <p...@kamp.de> > --- > block/iscsi.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/block/iscsi.c b/block/iscsi.c > index 93fee6d..75d6b87 100644 > --- a/block/iscsi.c > +++ b/block/iscsi.c > @@ -1580,6 +1580,13 @@ static int iscsi_get_info(BlockDriverState *bs, > BlockDriverInfo *bdi) > IscsiLun *iscsilun = bs->opaque; > bdi->unallocated_blocks_are_zero = !!iscsilun->lbprz; > bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && > iscsilun->lbp.lbpws; > + /* Guess the internal cluster (page) size of the iscsi target by the > means > + * of opt_unmap_gran. Transfer the unmap granularity only if it has a > + * reasonable size for bdi->cluster_size */ > + if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 64 * 1024 && > + iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * > 1024) { > + bdi->cluster_size = iscsilun->bl.opt_unmap_gran * > iscsilun->block_size; > + } > return 0; > } > >
After looking at patch 5, I think this one is correct. Reviewed-by: Paolo Bonzini <pbonz...@redhat.com> but I think you should make higher layers (qcow2) use the lower BDS's granularity, at least as a default. Paolo