From 3d2acaa308bfab65329ef983654b302899bfb2b0 Mon Sep 17 00:00:00 2001
From: Peter Lieven <pl@kamp.de>
Date: Mon, 28 Apr 2014 17:18:32 +0200
Subject: [PATCH] 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>
---
block/iscsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index e8d26bb781..84bedfa8fc 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -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;
--
2.30.2