Wrap creating the sorted subkey cache in a transaction

Signed-off-by: Michael Adam <obnox@samba.org>

diff --git a/source/registry/reg_backend_db.c b/source/registry/reg_backend_db.c
index 344bc4124d360797db07d06e4323c3e03fb0811e..689bd1038e3ea0d4a0c731932af7e08baae826fd 100644 (file)
--- a/source/registry/reg_backend_db.c
+++ b/source/registry/reg_backend_db.c
@@ -920,9 +920,15 @@ static bool create_sorted_subkeys(const char *key, const char *sorted_keyname)
        int i, res;
        size_t len;
 
+       if (regdb->transaction_start(regdb) != 0) {
+               DEBUG(0, ("create_sorted_subkeys: transaction_start "
+                         "failed\n"));
+               return false;
+       }
+
        ctr = talloc(talloc_tos(), REGSUBKEY_CTR);
        if (ctr == NULL) {
-               return false;
+               goto fail;
        }
 
        res = regdb_fetch_keys(key, ctr);
@@ -963,15 +969,37 @@ static bool create_sorted_subkeys(const char *key, const char *sorted_keyname)
                p += strlen(sorted_subkeys[i]) + 1;
        }
 
-       status = dbwrap_trans_store_bystring(
+       status = dbwrap_store_bystring(
                regdb, sorted_keyname, make_tdb_data((uint8_t *)buf, len),
                TDB_REPLACE);
        if (!NT_STATUS_IS_OK(status)) {
-               goto fail;
+               /*
+                * Don't use a "goto fail;" here, this would commit the broken
+                * transaction. See below for an explanation.
+                */
+               if (regdb->transaction_cancel(regdb) == -1) {
+                       DEBUG(0, ("create_sorted_subkeys: transaction_cancel "
+                                 "failed\n"));
+               }
+               TALLOC_FREE(ctr);
+               return false;
        }
 
        result = true;
  fail:
+       /*
+        * We only get here via the "goto fail" when we did not write anything
+        * yet. Using transaction_commit even in a failure case is necessary
+        * because this (disposable) call might be nested in other
+        * transactions. Doing a cancel here would destroy the possibility of
+        * a transaction_commit for transactions that we might be wrapped in.
+        */
+       if (regdb->transaction_commit(regdb) == -1) {
+               DEBUG(0, ("create_sorted_subkeys: transaction_start "
+                         "failed\n"));
+               goto fail;
+       }
+
        TALLOC_FREE(ctr);
        return result;
 }