[Qemu-devel] [RFC][PATCH 1.8] block/iscsi: set bdi->cluster_size

[Peter Lieven <pl@kamp.de>]

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 <pl@kamp.de>
---
 block/iscsi.c |    6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/block/iscsi.c b/block/iscsi.c
index b7b5238..3a4c5d4 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1569,6 +1569,12 @@ 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;
+    bdi->cluster_size = iscsilun->bl.opt_xfer_len * iscsilun->block_size;
+    /* if opt_xfer_len is not specified guess the internal page size of the
+     * iscsi target by the means of opt_unmap_gran */
+    if (bdi->cluster_size == 0) {
+        bdi->cluster_size = iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
+    }
     return 0;
 }
 
-- 
1.7.9.5