iscsi: Set request_alignment during .bdrv_refresh_limits()

We want to eventually stick request_alignment alongside other
BlockLimits, but first, we must ensure it is populated at the
same time as all other limits, rather than being a special case
that is set only when a block is first opened.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/iscsi.c

@@ -1589,7 +1589,6 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
         goto out;
     }
     bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
-    bs->request_alignment = iscsilun->block_size;
 
     /* We don't have any emulation for devices other than disks and CD-ROMs, so
      * this must be sg ioctl compatible. We force it to be sg, otherwise qemu
@@ -1711,6 +1710,8 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
     IscsiLun *iscsilun = bs->opaque;
     uint32_t max_xfer_len = iscsilun->use_16_for_rw ? 0xffffffff : 0xffff;
 
+    bs->request_alignment = iscsilun->block_size;
+
     if (iscsilun->bl.max_xfer_len) {
         max_xfer_len = MIN(max_xfer_len, iscsilun->bl.max_xfer_len);
     }