commit 3d2acaa308bfab65329ef983654b302899bfb2b0
author Peter Lieven <pl@kamp.de> Mon Apr 28 17:18:32 2014 +0200
committer Paolo Bonzini <pbonzini@redhat.com> Tue Apr 29 11:15:01 2014 +0200
tree 83f433e25ec0aba8e1a183151c4d63b8b1e2e296
parent 5917af812e9c4bd6500927b26efe8d3e2f267bd0

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

diff --git a/block/iscsi.c b/block/iscsi.c
index e8d26bb..84bedfa 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1386,7 +1386,7 @@
     /* 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;