f2fs: inject ENOSPC failures

This patch injects ENOSPC failures.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/dir.c

@@ -537,6 +537,10 @@ int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
 	}
 
 start:
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+	if (time_to_inject(FAULT_DIR_DEPTH))
+		return -ENOSPC;
+#endif
 	if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
 		return -ENOSPC;