block/iscsi: allow cluster_size of 4K and greater

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
feature lower the barrier. The limit 4K (and not 512) is choosen
to avoid a potentially too big allocationmap.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Lieven 2014-04-28 17:18:32 +02:00 committed by Paolo Bonzini
parent 5917af812e
commit 3d2acaa308
1 changed files with 1 additions and 1 deletions

View File

@ -1386,7 +1386,7 @@ 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;