[TD-1920]add mnode_bak and mnode_tmp dir exist check when start up

src/dnode/src/dnodeMain.c

@@ -219,14 +219,20 @@ static int32_t dnodeInitStorage() {
 
   if (tsCompactMnodeWal == 1) {
     sprintf(tsMnodeTmpDir, "%s/mnode_tmp", tsDataDir);
-    tfsRmdir(tsMnodeTmpDir);
+    if (taosDirExist(tsMnodeTmpDir)) {
+      dError("mnode_tmp dir already exist in %s,quit compact job", tsMnodeTmpDir);
+      return -1;
+    }
     if (dnodeCreateDir(tsMnodeTmpDir) < 0) {
       dError("failed to create dir: %s, reason: %s", tsMnodeTmpDir, strerror(errno));
       return -1;
     }
 
     sprintf(tsMnodeBakDir, "%s/mnode_bak", tsDataDir);
-    //tfsRmdir(tsMnodeBakDir);   
+    if (taosDirExist(tsMnodeBakDir)) {
+      dError("mnode_bak dir already exist in %s,quit compact job", tsMnodeBakDir);
+      return -1;
+    }
   }
   //TODO(dengyihao): no need to init here 
   if (dnodeCreateDir(tsMnodeDir) < 0) {

src/os/inc/osDir.h

@@ -21,6 +21,7 @@ extern "C" {
 #endif
 
 void    taosRemoveDir(char *rootDir);
+bool    taosDirExist(const char* dirname);
 int32_t taosMkDir(const char *pathname, mode_t mode);
 void    taosRemoveOldLogFiles(char *rootDir, int32_t keepDays);
 int32_t taosRename(char *oldName, char *newName);

src/os/src/detail/osDir.c

@@ -45,6 +45,10 @@ void taosRemoveDir(char *rootDir) {
   uInfo("dir:%s is removed", rootDir);
 }
 
+bool taosDirExist(const char* dirname) {
+  return access(dirname, F_OK) == 0;
+}
+
 int taosMkDir(const char *path, mode_t mode) {
   int code = mkdir(path, 0755);
   if (code < 0 && errno == EEXIST) code = 0;