tests: drivermodule: Make sure that all compiled storage backends can be loaded

Add a new storage driver registration function that will force the
backend code to fail if any of the storage backend modules can't be
loaded. This will make sure that they work and are present.

src/storage/storage_backend.c

@@ -87,7 +87,8 @@ static size_t virStorageFileBackendsCount;
 
 static int
 virStorageDriverLoadBackendModule(const char *name,
-                                  const char *regfunc)
+                                  const char *regfunc,
+                                  bool forceload)
 {
     char *modfile = NULL;
     int ret;
@@ -100,7 +101,14 @@ virStorageDriverLoadBackendModule(const char *name,
                                             "LIBVIRT_STORAGE_BACKEND_DIR")))
         return 1;
 
-    ret = virDriverLoadModuleFull(modfile, regfunc, NULL);
+    if ((ret = virDriverLoadModuleFull(modfile, regfunc, NULL)) != 0) {
+        if (forceload) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("failed to load storage backend module '%s'"),
+                           name);
+            ret = -1;
+        }
+    }
 
     VIR_FREE(modfile);
 
@@ -109,7 +117,7 @@ virStorageDriverLoadBackendModule(const char *name,
 
 
 # define VIR_STORAGE_BACKEND_REGISTER(func, module)                            \
-    if (virStorageDriverLoadBackendModule(module, #func) < 0)                  \
+    if (virStorageDriverLoadBackendModule(module, #func, allbackends) < 0)     \
         return -1
 #else
 # define VIR_STORAGE_BACKEND_REGISTER(func, module)                            \
@@ -118,7 +126,7 @@ virStorageDriverLoadBackendModule(const char *name,
 #endif
 
 int
-virStorageBackendDriversRegister(void)
+virStorageBackendDriversRegister(bool allbackends ATTRIBUTE_UNUSED)
 {
 #if WITH_STORAGE_DIR || WITH_STORAGE_FS
     VIR_STORAGE_BACKEND_REGISTER(virStorageBackendFsRegister, "fs");

src/storage/storage_backend.h

@@ -198,7 +198,7 @@ struct _virStorageFileBackend {
     virStorageFileBackendChown  storageFileChown;
 };
 
-int virStorageBackendDriversRegister(void);
+int virStorageBackendDriversRegister(bool allmodules);
 
 int virStorageBackendRegister(virStorageBackendPtr backend);
 int virStorageBackendFileRegister(virStorageFileBackendPtr backend);

src/storage/storage_driver.c

@@ -2838,9 +2838,10 @@ static virStateDriver stateDriver = {
     .stateReload = storageStateReload,
 };
 
-int storageRegister(void)
+static int
+storageRegisterFull(bool allbackends)
 {
-    if (virStorageBackendDriversRegister() < 0)
+    if (virStorageBackendDriversRegister(allbackends) < 0)
         return -1;
     if (virSetSharedStorageDriver(&storageDriver) < 0)
         return -1;
@@ -2850,6 +2851,20 @@ int storageRegister(void)
 }
 
 
+int
+storageRegister(void)
+{
+    return storageRegisterFull(false);
+}
+
+
+int
+storageRegisterAll(void)
+{
+    return storageRegisterFull(true);
+}
+
+
 /* ----------- file handlers cooperating with storage driver --------------- */
 static bool
 virStorageFileIsInitialized(const virStorageSource *src)

src/storage/storage_driver.h

@@ -70,5 +70,6 @@ char *virStoragePoolObjBuildTempFilePath(virStoragePoolObjPtr pool,
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
 
 int storageRegister(void);
+int storageRegisterAll(void);
 
 #endif /* __VIR_STORAGE_DRIVER_H__ */

tests/virdrivermoduletest.c

@@ -71,7 +71,7 @@ mymain(void)
     TEST("interface");
 #endif
 #ifdef WITH_STORAGE
-    TEST("storage");
+    TEST_FULL("storage", "storageRegisterAll");
 #endif
 #ifdef WITH_NODE_DEVICES
     TEST("nodedev");

tests/virstoragetest.c

@@ -732,7 +732,7 @@ mymain(void)
     virStorageSourcePtr chain2; /* short for chain->backingStore */
     virStorageSourcePtr chain3; /* short for chain2->backingStore */
 
-    if (virStorageBackendDriversRegister() < 0)
+    if (virStorageBackendDriversRegister(false) < 0)
        return -1;
 
     /* Prep some files with qemu-img; if that is not found on PATH, or