[Qemu-devel] [PATCH 6/5] iscsi: Rely on block layer to break up large requests

[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>
---
 block/iscsi.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 16d7522..0f027ce 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -473,11 +473,8 @@ 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);
@@ -651,11 +648,8 @@ 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 (iscsilun->lbprz && nb_sectors >= ISCSI_CHECKALLOC_THRES &&
-- 
2.5.5