blk/aio: fix incomplete patch to get rid off aio_size

Signed-off-by: Igor Fedotov <igor.fedotov@croit.io>

src/blk/aio/aio.cc

@@ -29,18 +29,25 @@ int aio_queue_t::submit_batch(aio_iter begin, aio_iter end,
   struct aio_t *piocb[max_iodepth];
 #endif
   int done = 0;
-  while (cur != end) {
+  int itemCount0 = 0; //used for LIBAIO only
+  int itemCount = 0;
+  while (cur != end || itemCount0 < itemCount) {
 #if defined(HAVE_LIBAIO)
-    int itemCount = 0;
     while (cur != end && itemCount < max_iodepth) {
       cur->priv = priv;
       piocb[itemCount] = &(*cur);
       ++itemCount;
       ++cur;
     }
-    r = io_submit(ctx, itemCount, (struct iocb**)piocb);
+    int toSubmit = itemCount - itemCount0;
+    r = io_submit(ctx, toSubmit, (struct iocb**)(piocb + itemCount0));
+    if (r >= 0 && r < toSubmit) {
+      r = -EAGAIN;
+      itemCount0 += (r > 0 ? r : 0);
+      done += (r > 0 ? r : 0);
+    }
 #elif defined(HAVE_POSIXAIO)
-    cur->priv = priv
+    cur->priv = priv;
     if ((cur->n_aiocb == 1) {
       // TODO: consider batching multiple reads together with lio_listio
       cur->aio.aiocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;
@@ -69,6 +76,7 @@ int aio_queue_t::submit_batch(aio_iter begin, aio_iter end,
     done += r;
     attempts = 16;
     delay = 125;
+    itemCount0 = itemCount = 0;
   }
   return done;
 }