fs: Add fs_dir_t_init() function

The fs_dir_t_init() function has been added that should be used
for initialization of fs_dir_t structures before passing them
to fs_open and other functions.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>

include/fs/fs.h

@@ -234,6 +234,20 @@ static inline void fs_file_t_init(struct fs_file_t *zfp)
 	*zfp = (struct fs_file_t){ 0 };
 }
 
+/**
+ * @brief Initialize fs_dir_t object
+ *
+ * Initializes the fs_dir_t object; the function needs to be invoked
+ * on object before first use with fs_opendir.
+ *
+ * @param zdp Pointer to file object
+ *
+ */
+static inline void fs_dir_t_init(struct fs_dir_t *zdp)
+{
+	*zdp = (struct fs_dir_t){ 0 };
+}
+
 /**
  * @brief Open or create file
  *

include/fs/fs_interface.h

@@ -59,6 +59,8 @@ struct fs_file_t {
 /**
  * @brief Directory object representing an open directory
  *
+ * The object needs to be initialized with function fs_dir_t_init().
+ *
  * @param dirp Pointer to directory object structure
  * @param mp Pointer to mount point structure
  */

tests/subsys/fs/fs_api/src/main.c

@@ -73,6 +73,7 @@ void test_main(void)
 							fs_setup,
 							dummy_teardown),
 			 ztest_unit_test(test_fs_file_t_init),
+			 ztest_unit_test(test_fs_dir_t_init),
 			 ztest_unit_test(test_file_statvfs),
 			 ztest_unit_test(test_mkdir),
 			 ztest_unit_test(test_opendir),

tests/subsys/fs/fs_api/src/test_fs.h

@@ -32,6 +32,7 @@ struct test_fs_data {
 	int reserve;
 };
 
+void test_fs_dir_t_init(void);
 void test_fs_file_t_init(void);
 void test_fs_register(void);
 void test_mount(void);

tests/subsys/fs/fs_api/src/test_fs_dir_file.c

@@ -93,6 +93,20 @@ void test_fs_file_t_init(void)
 	zassert_equal(fst.flags, 0, "Expected to be initialized to 0");
 }
 
+/**
+ * @brief Test fs_dir_t_init initializer
+ */
+void test_fs_dir_t_init(void)
+{
+	struct fs_dir_t dirp;
+
+	memset(&dirp, 0xff, sizeof(dirp));
+
+	fs_dir_t_init(&dirp);
+	zassert_equal(dirp.mp, NULL, "Expected to be initialized to NULL");
+	zassert_equal(dirp.dirp, NULL, "Expected to be initialized to NULL");
+}
+
 /**
  * @brief Test mount interface of filesystem
  *
@@ -263,7 +277,8 @@ void test_opendir(void)
 
 	TC_PRINT("\nopendir tests:\n");
 
-	memset(&dirp, 0, sizeof(dirp));
+	fs_dir_t_init(&dirp);
+
 	TC_PRINT("Test null path\n");
 	ret = fs_opendir(NULL, NULL);
 	zassert_not_equal(ret, 0, "Open dir with NULL pointer parameter");
@@ -307,7 +322,7 @@ void test_closedir(void)
 	struct fs_dir_t dirp;
 
 	TC_PRINT("\nclosedir tests: %s\n", TEST_DIR);
-	memset(&dirp, 0, sizeof(dirp));
+	fs_dir_t_init(&dirp);
 	ret = fs_opendir(&dirp, TEST_DIR);
 	zassert_equal(ret, 0, "Fail to open dir");
 
@@ -331,7 +346,7 @@ static int _test_lsdir(const char *path)
 
 	TC_PRINT("\nlsdir tests:\n");
 
-	memset(&dirp, 0, sizeof(dirp));
+	fs_dir_t_init(&dirp);
 	memset(&entry, 0, sizeof(entry));
 
 	TC_PRINT("read an unopened dir\n");