diff --git a/fs/inode/fs_files.c b/fs/inode/fs_files.c
index 9f04b2197c134..63312f7d02048 100644
--- a/fs/inode/fs_files.c
+++ b/fs/inode/fs_files.c
@@ -68,6 +68,7 @@ static FAR struct file *files_fget(int fd, FAR struct filelist *list)
 static int files_extend(FAR struct filelist *list, size_t row)
 {
   FAR struct file **tmp;
+  irqstate_t flags;
   int i;
 
   if (row <= list->fl_rows)
@@ -80,7 +81,7 @@ static int files_extend(FAR struct filelist *list, size_t row)
       return -EMFILE;
     }
 
-  tmp = kmm_realloc(list->fl_files, sizeof(FAR struct file *) * row);
+  tmp = kmm_malloc(sizeof(FAR struct file *) * row);
   DEBUGASSERT(tmp);
   if (tmp == NULL)
     {
@@ -105,9 +106,16 @@ static int files_extend(FAR struct filelist *list, size_t row)
     }
   while (++i < row);
 
+  flags = enter_critical_section();
+
+  memcpy(tmp, list->fl_files,
+         list->fl_rows * sizeof(FAR struct file *));
+
   list->fl_files = tmp;
   list->fl_rows = row;
 
+  leave_critical_section(flags);
+
   /* Note: If assertion occurs, the fl_rows has a overflow.
    * And there may be file descriptors leak in system.
    */
@@ -594,26 +602,42 @@ int fs_getfilep(int fd, FAR struct file **filep)
    * thread-specific file list.
    */
 
-  /* And return the file pointer from the list */
-
-  ret = nxmutex_lock(&list->fl_lock);
-  if (ret < 0)
+  if (!nxmutex_is_locked(&list->fl_lock))
     {
-      leave_critical_section(flags);
-      return ret;
+      *filep = files_fget(fd, list);
+
+      /* if f_inode is NULL, fd was closed */
+
+      if (!(*filep)->f_inode)
+        {
+          *filep = NULL;
+          ret = -EBADF;
+        }
     }
+  else
+    {
+      /* And return the file pointer from the list */
 
-  *filep = files_fget(fd, list);
+      ret = nxmutex_lock(&list->fl_lock);
+      if (ret < 0)
+        {
+          leave_critical_section(flags);
+          return ret;
+        }
 
-  /* if f_inode is NULL, fd was closed */
+      *filep = files_fget(fd, list);
 
-  if (!(*filep)->f_inode)
-    {
-      *filep = NULL;
-      ret = -EBADF;
+      /* if f_inode is NULL, fd was closed */
+
+      if (!(*filep)->f_inode)
+        {
+          *filep = NULL;
+          ret = -EBADF;
+        }
+
+      nxmutex_unlock(&list->fl_lock);
     }
 
-  nxmutex_unlock(&list->fl_lock);
   leave_critical_section(flags);
   return ret;
 }