Adjust the fix so calling other file operations (e.g. write, read etc.) after close() not crash the system

Author: geza-pycom

esp32/littlefs/vfs_littlefs_file.c

@@ -21,6 +21,7 @@ typedef struct _pyb_file_obj_t {
     vfs_lfs_struct_t* littlefs;
     struct lfs_file_config cfg;  // Attributes of the file, e.g.: timestamp
     bool timestamp_update;  // For requesting timestamp update when closing the file
+    bool opened; // Indicate whether the file is opened
 } pyb_file_obj_t;
 
 STATIC void file_obj_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
@@ -101,7 +102,8 @@ STATIC mp_uint_t file_obj_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_t arg,
         return 0;
 
     } else if (request == MP_STREAM_CLOSE) {
-        if (self->littlefs == NULL) {
+        // This check is needed here because calling close() twice makes LFS crash in lfs_file_close()
+        if (self->opened == false) {
             return 0;
         }
 
@@ -113,7 +115,7 @@ STATIC mp_uint_t file_obj_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_t arg,
             *errcode = littleFsErrorToErrno(res);
             return MP_STREAM_ERROR;
         }
-        self->littlefs = NULL; // indicate a closed file
+        self->opened = false; // indicate a closed file
         return 0;
     } else {
         *errcode = MP_EINVAL;
@@ -168,6 +170,7 @@ STATIC mp_obj_t file_open(fs_user_mount_t *vfs, const mp_obj_type_t *type, mp_ar
     pyb_file_obj_t *o = m_new_obj_with_finaliser(pyb_file_obj_t);
     o->base.type = type;
     o->timestamp_update = false;
+    o->opened = false;
 
     xSemaphoreTake(vfs->fs.littlefs.mutex, portMAX_DELAY);
         const char *fname = concat_with_cwd(&vfs->fs.littlefs, mp_obj_str_get_str(args[0].u_obj));
@@ -181,6 +184,7 @@ STATIC mp_obj_t file_open(fs_user_mount_t *vfs, const mp_obj_type_t *type, mp_ar
     }
 
     o->littlefs = &vfs->fs.littlefs;
+    o->opened = true; // File is opened successfully
 
     return MP_OBJ_FROM_PTR(o);
 }