mufs: embed struct mufs_dtree in struct mufs_dentry and clean up code

source/fs/mufs/dir.c

@@ -1,3 +1,4 @@
+#include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -216,21 +217,15 @@ static size_t read_dirent(struct mufs *fs, struct mufs_tree *tree,
 	dirent->tree.fs = fs;
 	dirent->tree.va = dirent->tree.va << dev->log2_block_size;
 	/* TODO: get a proper offset to the tree. */
-	dirent->tree.va += 1;
+	dirent->tree.va += offsetof(struct mufs_dentry, tree);
 	dirent->tree.va += base & ((UINT32_C(1) << dev->log2_block_size) - 1);
-	dirent->tree.file_size = entry.file_size;
-	dirent->tree.root = entry.root;
-	dirent->tree.depth = entry.depth;
+	dirent->tree.file_size = entry.tree.file_size;
+	dirent->tree.root = entry.tree.root;
+	dirent->tree.depth = entry.tree.depth;
 
 	return ret;
 }
 
-struct mufs_dtree {
-	uint32_t file_size;
-	uint32_t root;
-	uint8_t depth;
-} __attribute__((packed));
-
 static size_t write_dirent(struct mufs_tree *tree,
 	uint32_t va, struct mufs_dirent *dirent)
 {
@@ -238,9 +233,9 @@ static size_t write_dirent(struct mufs_tree *tree,
 	struct mufs_dentry entry;
 
 	entry.type = dirent->type;
-	entry.file_size = dirent->tree.file_size;
-	entry.root = dirent->tree.root;
-	entry.depth = dirent->tree.depth;
+	entry.tree.file_size = dirent->tree.file_size;
+	entry.tree.root = dirent->tree.root;
+	entry.tree.depth = dirent->tree.depth;
 	entry.path_len = strlen(dirent->path);
 
 	if (mufs_write(tree, dirent->path, va + sizeof entry,

source/fs/mufs/dir.h

@@ -1,10 +1,14 @@
 #pragma once
 
-struct mufs_dentry {
-	uint8_t type;
+struct mufs_dtree {
 	uint32_t file_size;
 	uint32_t root;
 	uint8_t depth;
+} __attribute__((packed));
+
+struct mufs_dentry {
+	uint8_t type;
+	struct mufs_dtree tree;
 	uint16_t path_len;
 } __attribute__((packed));