diff --git a/components/fs/fs.c b/components/fs/fs.c
index a06212a3f4899b06abad994c60e6c8880c48d6f1..636667f9b22d32a64cc0182d30a6db0402bf3944 100644
--- a/components/fs/fs.c
+++ b/components/fs/fs.c
@@ -347,14 +347,14 @@ ssize_t read(int fd, void *buf, size_t nbyte)
         return recv(fd, buf, nbyte, 0);
     }
 #endif
-    if (g_fs->fsFops == NULL || g_fs->fsFops->Read == NULL) {
-        errno = ENOSYS;
-        return FS_FAILURE;
-    }
     if (g_fs == NULL) {
         errno = ENODEV;
         return FS_FAILURE;
     }
+    if (g_fs->fsFops == NULL || g_fs->fsFops->Read == NULL) {
+        errno = ENOSYS;
+        return FS_FAILURE;
+    }
     return g_fs->fsFops->Read(fd, buf, nbyte);
 }