diff --git a/include/os/osString.h b/include/os/osString.h
index c78c740cf6..63c7aca58c 100644
--- a/include/os/osString.h
+++ b/include/os/osString.h
@@ -96,11 +96,9 @@ int32_t taosStr2Uint32(const char *str, uint32_t *val);
 int32_t taosStr2Uint16(const char *str, uint16_t *val);
 int32_t taosStr2Uint8(const char *str, uint8_t *val);
 
-int32_t taosConvInit(void);
-void    taosConvDestroy();
-iconv_t taosAcquireConv(int32_t *idx, ConvType type);
-void    taosReleaseConv(int32_t idx, iconv_t conv, ConvType type);
-int32_t taosUcs4ToMbs(TdUcs4 *ucs4, int32_t ucs4_max_len, char *mbs);
+iconv_t taosAcquireConv(int32_t *idx, ConvType type, void* charsetCxt);
+void    taosReleaseConv(int32_t idx, iconv_t conv, ConvType type, void* charsetCxt);
+int32_t taosUcs4ToMbs(TdUcs4 *ucs4, int32_t ucs4_max_len, char *mbs, void* charsetCxt);
 int32_t taosUcs4ToMbsEx(TdUcs4 *ucs4, int32_t ucs4_max_len, char *mbs, iconv_t conv);
 bool    taosMbsToUcs4(const char *mbs, size_t mbs_len, TdUcs4 *ucs4, int32_t ucs4_max_len, int32_t *len, void* charsetCxt);
 int32_t tasoUcs4Compare(TdUcs4 *f1_ucs4, TdUcs4 *f2_ucs4, int32_t bytes);
@@ -129,7 +127,6 @@ double   taosStr2Double(const char *str, char **pEnd);
 float    taosStr2Float(const char *str, char **pEnd);
 int32_t  taosHex2Ascii(const char *z, uint32_t n, void **data, uint32_t *size);
 int32_t  taosAscii2Hex(const char *z, uint32_t n, void **data, uint32_t *size);
-char    *taosStrndup(const char *s, int n);
 // int32_t  taosBin2Ascii(const char *z, uint32_t n, void** data, uint32_t* size);
 bool isHex(const char *z, uint32_t n);
 bool isValidateHex(const char *z, uint32_t n);
diff --git a/source/os/src/osString.c b/source/os/src/osString.c
index caa43f7459..380e9f84d3 100644
--- a/source/os/src/osString.c
+++ b/source/os/src/osString.c
@@ -308,67 +308,8 @@ int32_t tasoUcs4Copy(TdUcs4 *target_ucs4, TdUcs4 *source_ucs4, int32_t len_ucs4)
   return TSDB_CODE_SUCCESS;
 }
 
-typedef struct {
-  iconv_t conv;
-  int8_t  inUse;
-} SConv;
-
-// 0: Mbs --> Ucs4
-// 1: Ucs4--> Mbs
-SConv  *gConv[2] = {NULL, NULL};
-int32_t convUsed[2] = {0, 0};
-int32_t gConvMaxNum[2] = {0, 0};
-
-int32_t taosConvInit(void) {
-  int8_t M2C = 0;
-  gConvMaxNum[M2C] = 512;
-  gConvMaxNum[1 - M2C] = 512;
-
-  gConv[M2C] = taosMemoryCalloc(gConvMaxNum[M2C], sizeof(SConv));
-  if (gConv[M2C] == NULL) {
-    return terrno;
-  }
-
-  gConv[1 - M2C] = taosMemoryCalloc(gConvMaxNum[1 - M2C], sizeof(SConv));
-  if (gConv[1 - M2C] == NULL) {
-    taosMemoryFree(gConv[M2C]);
-    return terrno;
-  }
-
-  for (int32_t i = 0; i < gConvMaxNum[M2C]; ++i) {
-    gConv[M2C][i].conv = iconv_open(DEFAULT_UNICODE_ENCODEC, tsCharset);
-    if ((iconv_t)-1 == gConv[M2C][i].conv) {
-      terrno = TAOS_SYSTEM_ERROR(errno);
-      return terrno;
-    }
-  }
-  for (int32_t i = 0; i < gConvMaxNum[1 - M2C]; ++i) {
-    gConv[1 - M2C][i].conv = iconv_open(tsCharset, DEFAULT_UNICODE_ENCODEC);
-    if ((iconv_t)-1 == gConv[1 - M2C][i].conv) {
-      terrno = TAOS_SYSTEM_ERROR(errno);
-      return terrno;
-    }
-  }
-
-  return 0;
-}
-
-void taosConvDestroy() {
-  int8_t M2C = 0;
-  for (int32_t i = 0; i < gConvMaxNum[M2C]; ++i) {
-    (void)iconv_close(gConv[M2C][i].conv);
-  }
-  for (int32_t i = 0; i < gConvMaxNum[1 - M2C]; ++i) {
-    (void)iconv_close(gConv[1 - M2C][i].conv);
-  }
-  taosMemoryFreeClear(gConv[M2C]);
-  taosMemoryFreeClear(gConv[1 - M2C]);
-  gConvMaxNum[M2C] = -1;
-  gConvMaxNum[1 - M2C] = -1;
-}
-
-iconv_t taosAcquireConv(int32_t *idx, ConvType type) {
-  if (idx == NULL) {
+iconv_t taosAcquireConv(int32_t *idx, ConvType type, void* charsetCxt) {
+  if(idx == NULL) {
     terrno = TSDB_CODE_INVALID_PARA;
     return (iconv_t)-1;
   }
@@ -512,12 +453,12 @@ int32_t taosUcs4ToMbs(TdUcs4 *ucs4, int32_t ucs4_max_len, char *mbs, void* chars
   size_t outLen = ucs4_max_len;
   if (iconv(conv, (char **)&ucs4, &ucs4_input_len, &mbs, &outLen) == -1) {
     code = TAOS_SYSTEM_ERROR(errno);
-    taosReleaseConv(idx, conv, C2M);
+    taosReleaseConv(idx, conv, C2M, charsetCxt);
     terrno = code;
     return code;
   }
 
-  taosReleaseConv(idx, conv, C2M);
+  taosReleaseConv(idx, conv, C2M, charsetCxt);
 
   return (int32_t)(ucs4_max_len - outLen);
 #endif
diff --git a/source/util/src/tutil.c b/source/util/src/tutil.c
index 9e993847fb..cdcef4b807 100644
--- a/source/util/src/tutil.c
+++ b/source/util/src/tutil.c
@@ -503,6 +503,31 @@ int32_t parseCfgReal(const char *str, float *out) {
   return TSDB_CODE_SUCCESS;
 }
 
+bool tIsValidFileName(const char *fileName, const char *pattern) {
+  const char *fileNamePattern = "^[a-zA-Z0-9_.-]+$";
+
+  regex_t fileNameReg;
+
+  if (pattern) fileNamePattern = pattern;
+
+  if (regcomp(&fileNameReg, fileNamePattern, REG_EXTENDED) != 0) {
+    fprintf(stderr, "failed to compile file name pattern:%s\n", fileNamePattern);
+    return false;
+  }
+
+  int32_t code = regexec(&fileNameReg, fileName, 0, NULL, 0);
+  regfree(&fileNameReg);
+  if (code != 0) {
+    return false;
+  }
+  return true;
+}
+
+bool tIsValidFilePath(const char *filePath, const char *pattern) {
+  const char *filePathPattern = "^[a-zA-Z0-9:/\\_.-]+$";
+  return tIsValidFileName(filePath, pattern ? pattern : filePathPattern);
+}
+
 bool taosIsBigChar(char c) {
   if (c >= 'A' && c <= 'Z') {
     return true;