commit 96f363d839f5fdae370afb9a9f843782dd1b38f8
author Markus Armbruster <armbru@redhat.com> Thu Sep 28 15:20:01 2023 +0200
committer Juan Quintela <quintela@redhat.com> Wed Oct 11 11:17:04 2023 +0200
tree de8f4582b7c25cc980647b553add3a43bb3aaa13
parent dcf07e72a4c929a06a5735e80b429f49b2278b9f

migration/rdma: Convert qemu_rdma_exchange_recv() to Error

Functions that use an Error **errp parameter to return errors should
not also report them to the user, because reporting is the caller's
job.  When the caller does, the error is reported twice.  When it
doesn't (because it recovered from the error), there is no error to
report, i.e. the report is bogus.

qio_channel_rdma_readv() violates this principle: it calls
error_report() via qemu_rdma_exchange_recv().  I elected not to
investigate how callers handle the error, i.e. precise impact is not
known.

Clean this up by converting qemu_rdma_exchange_recv() to Error.

Necessitates setting an error when qemu_rdma_exchange_get_response()
failed.  Since this error will go away later in this series, simply
use "FIXME temporary error message" there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20230928132019.2544702-36-armbru@redhat.com>

migration/rdma.c

diff --git a/migration/rdma.c b/migration/rdma.c
index fdb527a..b13fec6 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -1980,7 +1980,7 @@
  * control-channel message.
  */
 static int qemu_rdma_exchange_recv(RDMAContext *rdma, RDMAControlHeader *head,
-                                   uint32_t expecting)
+                                   uint32_t expecting, Error **errp)
 {
     RDMAControlHeader ready = {
                                 .len = 0,
@@ -1995,7 +1995,7 @@
     ret = qemu_rdma_post_send_control(rdma, NULL, &ready);
 
     if (ret < 0) {
-        error_report("Failed to send control buffer!");
+        error_setg(errp, "Failed to send control buffer!");
         return -1;
     }
 
@@ -2006,6 +2006,7 @@
                                           expecting, RDMA_WRID_READY);
 
     if (ret < 0) {
+        error_setg(errp, "FIXME temporary error message");
         return -1;
     }
 
@@ -2016,7 +2017,7 @@
      */
     ret = qemu_rdma_post_recv_control(rdma, RDMA_WRID_READY);
     if (ret < 0) {
-        error_report("rdma migration: error posting second control recv!");
+        error_setg(errp, "rdma migration: error posting second control recv!");
         return -1;
     }
 
@@ -2957,11 +2958,11 @@
         /* We've got nothing at all, so lets wait for
          * more to arrive
          */
-        ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_QEMU_FILE);
+        ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_QEMU_FILE,
+                                      errp);
 
         if (ret < 0) {
             rdma->errored = true;
-            error_setg(errp, "qemu_rdma_exchange_recv failed");
             return -1;
         }
 
@@ -3575,6 +3576,7 @@
     RDMAControlHeader blocks = { .type = RDMA_CONTROL_RAM_BLOCKS_RESULT,
                                  .repeat = 1 };
     QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(qemu_file_get_ioc(f));
+    Error *err = NULL;
     RDMAContext *rdma;
     RDMALocalBlocks *local;
     RDMAControlHeader head;
@@ -3604,9 +3606,10 @@
     do {
         trace_qemu_rdma_registration_handle_wait();
 
-        ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_NONE);
+        ret = qemu_rdma_exchange_recv(rdma, &head, RDMA_CONTROL_NONE, &err);
 
         if (ret < 0) {
+            error_report_err(err);
             break;
         }