[Qemu-devel] [PULL v2 06/25] iscsi: Rely on block layer to break up large requests

[Stefan Hajnoczi <stefanha@redhat.com>]

From: Eric Blake <eblake@redhat.com>

Now that the block layer honors max_request, we don't need to
bother with an EINVAL on overlarge requests, but can instead
assert that requests are well-behaved.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1468607524-19021-7-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/iscsi.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 129c3af..5602abd 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -586,11 +586,8 @@ iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
         return -EINVAL;
     }
 
-    if (bs->bl.max_transfer &&
-        nb_sectors << BDRV_SECTOR_BITS > bs->bl.max_transfer) {
-        error_report("iSCSI Error: Write of %d sectors exceeds max_xfer_len "
-                     "of %" PRIu32 " bytes", nb_sectors, bs->bl.max_transfer);
-        return -EINVAL;
+    if (bs->bl.max_transfer) {
+        assert(nb_sectors << BDRV_SECTOR_BITS <= bs->bl.max_transfer);
     }
 
     lba = sector_qemu2lun(sector_num, iscsilun);
@@ -754,11 +751,8 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
         return -EINVAL;
     }
 
-    if (bs->bl.max_transfer &&
-        nb_sectors << BDRV_SECTOR_BITS > bs->bl.max_transfer) {
-        error_report("iSCSI Error: Read of %d sectors exceeds max_xfer_len "
-                     "of %" PRIu32 " bytes", nb_sectors, bs->bl.max_transfer);
-        return -EINVAL;
+    if (bs->bl.max_transfer) {
+        assert(nb_sectors << BDRV_SECTOR_BITS <= bs->bl.max_transfer);
     }
 
     /* if cache.direct is off and we have a valid entry in our allocation map
-- 
2.7.4