exchange

commit 46da69710427458d402a55ce617ba28286923dba
parent fd8519d7cb869a5574cec6e686ef9c56505a73d4
Author: Christian Grothoff <grothoff@gnunet.org>
Date:   Sat, 15 Aug 2026 21:15:36 +0200

properly handle DB status on get_serial_by_table

Diffstat:
M
src/auditor/taler-auditor-sync.c
 | 
73
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------

1 file changed, 64 insertions(+), 9 deletions(-)
diff --git a/src/auditor/taler-auditor-sync.c b/src/auditor/taler-auditor-sync.c
@@ -580,6 +580,57 @@ do_insert (struct InsertContext *ctx,
 
 
 /**
+ * Determine the last serial number of each table in @a db.
+ *
+ * Failing to determine a serial must abort the pass: the previous
+ * value of the field is stale (#tables is file-scope), and continuing
+ * with it would silently skip records or entire tables.
+ *
+ * @param db database to query
+ * @param source true to store the result in the `end_serial` of each
+ *        table (data source), false for `start_serial` (destination)
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR to rollback
+ */
+static enum GNUNET_GenericReturnValue
+lookup_serials (struct TALER_EXCHANGEDB_PostgresContext *db,
+                bool source)
+{
+  for (unsigned int i = 0; ! tables[i].end; i++)
+  {
+    uint64_t *serial = source
+      ? &tables[i].end_serial
+      : &tables[i].start_serial;
+    enum GNUNET_DB_QueryStatus qs;
+
+    qs = TALER_EXCHANGEDB_get_serial_by_table (db,
+                                               tables[i].rt,
+                                               serial);
+    switch (qs)
+    {
+    case GNUNET_DB_STATUS_HARD_ERROR:
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  "Failed to determine last serial of table `%s': hard error\n",
+                  rt_name (tables[i].rt));
+      global_ret = EXIT_FAILURE;
+      return GNUNET_SYSERR;
+    case GNUNET_DB_STATUS_SOFT_ERROR:
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "Serialization error determining last serial of table `%s' (will retry)\n",
+                  rt_name (tables[i].rt));
+      return GNUNET_SYSERR;
+    case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
+      /* Table is empty; the statement did not write *serial. */
+      *serial = 0;
+      break;
+    case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
+      break;
+    }
+  }
+  return GNUNET_OK;
+}
+
+
+/**
  * Run one replication transaction.
  *
  * @return #GNUNET_OK on success, #GNUNET_SYSERR to rollback
@@ -595,19 +646,19 @@ transact (void)
       TALER_EXCHANGEDB_start (src,
                               "lookup src serials"))
     return GNUNET_SYSERR;
-  for (unsigned int i = 0; ! tables[i].end; i++)
-    TALER_EXCHANGEDB_get_serial_by_table (src,
-                                          tables[i].rt,
-                                          &tables[i].end_serial);
+  if (GNUNET_OK !=
+      lookup_serials (src,
+                      true))
+    return GNUNET_SYSERR;
   TALER_EXCHANGEDB_rollback (src);
   if (GNUNET_OK !=
       TALER_EXCHANGEDB_start (dst,
                               "lookup dst serials"))
     return GNUNET_SYSERR;
-  for (unsigned int i = 0; ! tables[i].end; i++)
-    TALER_EXCHANGEDB_get_serial_by_table (dst,
-                                          tables[i].rt,
-                                          &tables[i].start_serial);
+  if (GNUNET_OK !=
+      lookup_serials (dst,
+                      false))
+    return GNUNET_SYSERR;
   TALER_EXCHANGEDB_rollback (dst);
   for (unsigned int i = 0; ! tables[i].end; i++)
   {
@@ -673,7 +724,11 @@ transact (void)
         GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                     "Serialization error committing transaction on table `%s' (will retry)\n",
                     rt_name (table->rt));
-        continue;
+        /* The rows of the failed commit are gone, but start_serial was
+           already advanced past them by do_insert(); continuing here
+           would leave a permanent hole. Restart the pass instead, which
+           re-reads the serials actually present in the destination. */
+        return GNUNET_SYSERR;
       }
       if (GNUNET_DB_STATUS_HARD_ERROR == qs)
       {