mufs: read and write file size during mount and format

source/fs/mufs/super.c

@@ -9,6 +9,7 @@
 struct mufs_super {
 	char magic[4];
 	uint32_t nblocks;
+	uint32_t file_size;
 	uint32_t root;
 	uint8_t depth;
 } __attribute__((packed));
@@ -28,6 +29,8 @@ int mufs_mount(struct mufs *fs, struct flash_dev *dev)
 
 	fs->dev = dev;
 	fs->nblocks = super.nblocks;
+
+	fs->root.file_size = super.file_size;
 	fs->root.root = super.root;
 	fs->root.depth = super.depth;
 
@@ -40,6 +43,8 @@ int mufs_format(struct flash_dev *dev)
 
 	memcpy(super.magic, "mufs", 4);
 	super.nblocks = flash_get_capacity(dev) >> dev->log2_block_size;
+
+	super.file_size = 0;
 	super.root = 0;
 	super.depth = 0;