migration/rdma: Convert qemu_rdma_exchange_get_response() 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.

qemu_rdma_exchange_send() and qemu_rdma_exchange_recv() violate this
principle: they call error_report() via
qemu_rdma_exchange_get_response().  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_get_response() to
Error.

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: <20230928132019.2544702-38-armbru@redhat.com>

1 files changed, 11 insertions, 11 deletions

diff --git a/migration/rdma.c b/migration/rdma.c
index 7866cf9bb7..87f2e6129e 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -1824,14 +1824,15 @@ static int qemu_rdma_post_recv_control(RDMAContext *rdma, int idx)
  * Block and wait for a RECV control channel message to arrive.
  */
 static int qemu_rdma_exchange_get_response(RDMAContext *rdma,
-                RDMAControlHeader *head, uint32_t expecting, int idx)
+                RDMAControlHeader *head, uint32_t expecting, int idx,
+                Error **errp)
 {
     uint32_t byte_len;
     int ret = qemu_rdma_block_for_wrid(rdma, RDMA_WRID_RECV_CONTROL + idx,
                                        &byte_len);
 
     if (ret < 0) {
-        error_report("rdma migration: recv polling control error!");
+        error_setg(errp, "rdma migration: recv polling control error!");
         return -1;
     }
 
@@ -1844,7 +1845,7 @@ static int qemu_rdma_exchange_get_response(RDMAContext *rdma,
         trace_qemu_rdma_exchange_get_response_none(control_desc(head->type),
                                              head->type);
     } else if (head->type != expecting || head->type == RDMA_CONTROL_ERROR) {
-        error_report("Was expecting a %s (%d) control message"
+        error_setg(errp, "Was expecting a %s (%d) control message"
                 ", but got: %s (%d), length: %d",
                 control_desc(expecting), expecting,
                 control_desc(head->type), head->type, head->len);
@@ -1854,11 +1855,12 @@ static int qemu_rdma_exchange_get_response(RDMAContext *rdma,
         return -1;
     }
     if (head->len > RDMA_CONTROL_MAX_BUFFER - sizeof(*head)) {
-        error_report("too long length: %d", head->len);
+        error_setg(errp, "too long length: %d", head->len);
         return -1;
     }
     if (sizeof(*head) + head->len != byte_len) {
-        error_report("Malformed length: %d byte_len %d", head->len, byte_len);
+        error_setg(errp, "Malformed length: %d byte_len %d",
+                   head->len, byte_len);
         return -1;
     }
 
@@ -1911,9 +1913,8 @@ static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head,
 
         ret = qemu_rdma_exchange_get_response(rdma, &resp_ignored,
                                               RDMA_CONTROL_READY,
-                                              RDMA_WRID_READY);
+                                              RDMA_WRID_READY, errp);
         if (ret < 0) {
-            error_setg(errp, "FIXME temporary error message");
             return -1;
         }
     }
@@ -1964,10 +1965,10 @@ static int qemu_rdma_exchange_send(RDMAContext *rdma, RDMAControlHeader *head,
 
         trace_qemu_rdma_exchange_send_waiting(control_desc(resp->type));
         ret = qemu_rdma_exchange_get_response(rdma, resp,
-                                              resp->type, RDMA_WRID_DATA);
+                                              resp->type, RDMA_WRID_DATA,
+                                              errp);
 
         if (ret < 0) {
-            error_setg(errp, "FIXME temporary error message");
             return -1;
         }
 
@@ -2011,10 +2012,9 @@ static int qemu_rdma_exchange_recv(RDMAContext *rdma, RDMAControlHeader *head,
      * Block and wait for the message.
      */
     ret = qemu_rdma_exchange_get_response(rdma, head,
-                                          expecting, RDMA_WRID_READY);
+                                          expecting, RDMA_WRID_READY, errp);
 
     if (ret < 0) {
-        error_setg(errp, "FIXME temporary error message");
         return -1;
     }