On 04/28/2014 09:18 AM, Peter Lieven wrote: > depending on the target the opt_unmap_gran might be as low > as 4K. As we know use this also as a knob to activate the allocationmap
s/know/now/
> feature lower the barrier. The limit 4K (and not 512) is choosen
> to avoid a potentially too big allocationmap.
>
> Signed-off-by: Peter Lieven <p...@kamp.de>
> ---
> block/iscsi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index eca8a22..944f2ce 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -1377,7 +1377,7 @@ static int iscsi_open(BlockDriverState *bs, QDict
> *options, int flags,
> /* 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 */
> - if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 64 * 1024 &&
> + if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&
> iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 *
> 1024) {
> iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *
> iscsilun->block_size) >>
> BDRV_SECTOR_BITS;
>
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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