s3:registry: wrap reg_deletekey() into a transaction

This is wrong layering but fixes a race condition.
(cherry picked from commit e3ad0456515c97f6697190c86b8cec4af8e1e190)

diff --git a/source3/registry/reg_api.c b/source3/registry/reg_api.c
index c7777a120f3a7e89be0624feedeeeb9f00f2808b..69b987a723d1589b683d58796a66c118a870162b 100644 (file)
--- a/source3/registry/reg_api.c
+++ b/source3/registry/reg_api.c
@@ -695,12 +695,19 @@ WERROR reg_deletekey(struct registry_key *parent, const char *path)
        err = reg_openkey(mem_ctx, parent, name, REG_KEY_READ, &key);
        W_ERROR_NOT_OK_GOTO_DONE(err);
 
+       err = regdb_transaction_start();
+       if (!W_ERROR_IS_OK(err)) {
+               DEBUG(0, ("reg_deletekey: Error starting transaction: %s\n",
+                         win_errstr(err)));
+               goto done;
+       }
+
        err = fill_subkey_cache(key);
-       W_ERROR_NOT_OK_GOTO_DONE(err);
+       W_ERROR_NOT_OK_GOTO(err, trans_done);
 
        if (regsubkey_ctr_numkeys(key->subkeys) > 0) {
                err = WERR_ACCESS_DENIED;
-               goto done;
+               goto trans_done;
        }
 
        /* no subkeys - proceed with delete */
@@ -710,7 +717,7 @@ WERROR reg_deletekey(struct registry_key *parent, const char *path)
 
                err = reg_openkey(mem_ctx, parent, name,
                                  KEY_CREATE_SUB_KEY, &tmp_key);
-               W_ERROR_NOT_OK_GOTO_DONE(err);
+               W_ERROR_NOT_OK_GOTO(err, trans_done);
 
                parent = tmp_key;
                name = end+1;
@@ -718,11 +725,24 @@ WERROR reg_deletekey(struct registry_key *parent, const char *path)
 
        if (name[0] == '\0') {
                err = WERR_INVALID_PARAM;
-               goto done;
+               goto trans_done;
        }
 
        err = delete_reg_subkey(parent->key, name);
 
+trans_done:
+       if (W_ERROR_IS_OK(err)) {
+               err = regdb_transaction_commit();
+               if (!W_ERROR_IS_OK(err)) {
+                       DEBUG(0, ("reg_deletekey: Error committing transaction: %s\n", win_errstr(err)));
+               }
+       } else {
+               WERROR err1 = regdb_transaction_cancel();
+               if (!W_ERROR_IS_OK(err1)) {
+                       DEBUG(0, ("reg_deletekey: Error cancelling transaction: %s\n", win_errstr(err1)));
+               }
+       }
+
 done:
        TALLOC_FREE(mem_ctx);
        return err;