migration/rdma: Fix save_page method to fail on polling error

qemu_rdma_save_page() reports polling error with error_report(), then
succeeds anyway.  This is because the variable holding the polling
status *shadows* the variable the function returns.  The latter
remains zero.

Broken since day one, and duplicated more recently.

Fixes: 2da776db4846 (rdma: core logic)
Fixes: b390afd8c50b (migration/rdma: Fix out of order wrid)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Message-ID: <20230921121312.1301864-2-armbru@redhat.com>

diff --git a/migration/rdma.c b/migration/rdma.c
index a2a3db35b1d1481adb06594ff387de642d0603c7..3915d1d7c97d15d145a70a7ded856d9dddf5081b 100644 (file)
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -3282,7 +3282,8 @@ static size_t qemu_rdma_save_page(QEMUFile *f,
      */
     while (1) {
         uint64_t wr_id, wr_id_in;
-        int ret = qemu_rdma_poll(rdma, rdma->recv_cq, &wr_id_in, NULL);
+        ret = qemu_rdma_poll(rdma, rdma->recv_cq, &wr_id_in, NULL);
+
         if (ret < 0) {
             error_report("rdma migration: polling error! %d", ret);
             goto err;
@@ -3297,7 +3298,8 @@ static size_t qemu_rdma_save_page(QEMUFile *f,
 
     while (1) {
         uint64_t wr_id, wr_id_in;
-        int ret = qemu_rdma_poll(rdma, rdma->send_cq, &wr_id_in, NULL);
+        ret = qemu_rdma_poll(rdma, rdma->send_cq, &wr_id_in, NULL);
+
         if (ret < 0) {
             error_report("rdma migration: polling error! %d", ret);
             goto err;