storage: Extract out mount command creation for FS Backend

Extract out the code that is used to create the MOUNT command
for starting the pool. We can use this for Storage Pool XML
to Argv testing to ensure code changes don't alter how a
storage pool is started.
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
ACKed-by: NMichal Privoznik <mprivozn@redhat.com>

src/storage/storage_backend_fs.c

@@ -330,19 +330,11 @@ virStorageBackendFileSystemIsMounted(virStoragePoolObjPtr pool)
     return ret;
 }
 
-/**
- * @pool storage pool to mount
- *
- * Ensure that a FS storage pool is mounted on its target location.
- * If already mounted, this is a no-op
- *
- * Returns 0 if successfully mounted, -1 on error
- */
-static int
-virStorageBackendFileSystemMount(virStoragePoolObjPtr pool)
+
+static virCommandPtr
+virStorageBackendFileSystemMountCmd(virStoragePoolDefPtr def,
+                                    const char *src)
 {
-    virStoragePoolDefPtr def = virStoragePoolObjGetDef(pool);
-    char *src = NULL;
     /* 'mount -t auto' doesn't seem to auto determine nfs (or cifs),
      *  while plain 'mount' does. We have to craft separate argvs to
      *  accommodate this */
@@ -353,23 +345,6 @@ virStorageBackendFileSystemMount(virStoragePoolObjPtr pool)
     bool cifsfs = (def->type == VIR_STORAGE_POOL_NETFS &&
                    def->source.format == VIR_STORAGE_POOL_NETFS_CIFS);
     virCommandPtr cmd = NULL;
-    int ret = -1;
-    int rc;
-
-    if (virStorageBackendFileSystemIsValid(pool) < 0)
-        return -1;
-
-    if ((rc = virStorageBackendFileSystemIsMounted(pool)) < 0)
-        return -1;
-
-    /* Short-circuit if already mounted */
-    if (rc == 1) {
-        VIR_INFO("Target '%s' is already mounted", def->target.path);
-        return 0;
-    }
-
-    if (!(src = virStorageBackendFileSystemGetPoolSource(pool)))
-        return -1;
 
     if (netauto)
         cmd = virCommandNewArgList(MOUNT,
@@ -404,6 +379,43 @@ virStorageBackendFileSystemMount(virStoragePoolObjPtr pool)
                                    def->target.path,
                                    NULL);
 
+    return cmd;
+}
+
+
+/**
+ * @pool storage pool to mount
+ *
+ * Ensure that a FS storage pool is mounted on its target location.
+ * If already mounted, this is a no-op
+ *
+ * Returns 0 if successfully mounted, -1 on error
+ */
+static int
+virStorageBackendFileSystemMount(virStoragePoolObjPtr pool)
+{
+    virStoragePoolDefPtr def = virStoragePoolObjGetDef(pool);
+    char *src = NULL;
+    virCommandPtr cmd = NULL;
+    int ret = -1;
+    int rc;
+
+    if (virStorageBackendFileSystemIsValid(pool) < 0)
+        return -1;
+
+    if ((rc = virStorageBackendFileSystemIsMounted(pool)) < 0)
+        return -1;
+
+    /* Short-circuit if already mounted */
+    if (rc == 1) {
+        VIR_INFO("Target '%s' is already mounted", def->target.path);
+        return 0;
+    }
+
+    if (!(src = virStorageBackendFileSystemGetPoolSource(pool)))
+        return -1;
+
+    cmd = virStorageBackendFileSystemMountCmd(def, src);
     if (virCommandRun(cmd, NULL) < 0)
         goto cleanup;