vfs_alloc_dentry (#54)

* vfs_alloc_dentry

* vfs_alloc_dentry

* 修正dentry被错误清空的问题

Co-authored-by: fslongjin <longjin@RinGoTek.cn>

kernel/filesystem/VFS/VFS.c

@@ -297,15 +297,12 @@ int64_t vfs_mkdir(const char *path, mode_t mode, bool from_userland)
         return -EEXIST;
     }
 
-    struct vfs_dir_entry_t *subdir_dentry = (struct vfs_dir_entry_t *)kzalloc(sizeof(struct vfs_dir_entry_t), 0);
+    struct vfs_dir_entry_t *subdir_dentry = vfs_alloc_dentry(pathlen - last_slash);
 
-    list_init(&subdir_dentry->subdirs_list);
-    list_init(&subdir_dentry->child_node_list);
     if (path[pathlen - 1] == '/')
         subdir_dentry->name_length = pathlen - last_slash - 2;
     else
         subdir_dentry->name_length = pathlen - last_slash - 1;
-    subdir_dentry->name = (char *)kmalloc(subdir_dentry->name_length + 1, 0);
     memset((void *)subdir_dentry->name, 0, subdir_dentry->name_length + 1);
 
     for (int i = last_slash + 1, cnt = 0; i < pathlen && cnt < subdir_dentry->name_length; ++i, ++cnt)
@@ -409,10 +406,9 @@ uint64_t do_open(const char *filename, int flags)
             parent_dentry = vfs_root_sb->root;
 
         // 创建新的文件
-        dentry = (struct vfs_dir_entry_t *)kzalloc(sizeof(struct vfs_dir_entry_t), 0);
+        dentry = vfs_alloc_dentry(path_len - tmp_index);
 
         dentry->name_length = path_len - tmp_index - 1;
-        dentry->name = (char *)kzalloc(dentry->name_length + 1, 0);
         strncpy(dentry->name, path + tmp_index + 1, dentry->name_length);
         // kdebug("to create new file:%s   namelen=%d", dentry->name, dentry->name_length)
         dentry->parent = parent_dentry;
@@ -513,7 +509,8 @@ struct vfs_dir_entry_t *vfs_alloc_dentry(const int name_size)
     struct vfs_dir_entry_t *dentry = (struct vfs_dir_entry_t *)kzalloc(sizeof(struct vfs_dir_entry_t), 0);
     if (unlikely(dentry == NULL))
         return NULL;
-    dentry->name = (char *)kzalloc(name_size, 0);
+    if (name_size != 0)
+        dentry->name = (char *)kzalloc(name_size, 0);
 
     // 初始化lockref
     spin_init(&dentry->lockref.lock);

kernel/filesystem/devfs/devfs.c

@@ -205,9 +205,7 @@ static __always_inline void __devfs_init_root_inode()
  */
 static __always_inline void __devfs_init_root_dentry()
 {
-    devfs_root_dentry = (struct vfs_dir_entry_t *)kzalloc(sizeof(struct vfs_dir_entry_t), 0);
-    list_init(&devfs_root_dentry->child_node_list);
-    list_init(&devfs_root_dentry->subdirs_list);
+    devfs_root_dentry = vfs_alloc_dentry(0);
     devfs_root_dentry->dir_ops = &devfs_dentry_ops;
 
     __devfs_init_root_inode();

kernel/filesystem/fat32/fat32.c

@@ -369,16 +369,11 @@ struct vfs_superblock_t *fat32_read_superblock(struct block_device *blk)
     printk_color(BLUE, BLACK, "FAT32 FSInfo\n\tFSI_LeadSig:%#018lx\n\tFSI_StrucSig:%#018lx\n\tFSI_Free_Count:%#018lx\n", fsbi->fsinfo.FSI_LeadSig, fsbi->fsinfo.FSI_StrucSig, fsbi->fsinfo.FSI_Free_Count);
 
     // 初始化超级块的dir entry
-    sb_ptr->root = (struct vfs_dir_entry_t *)kmalloc(sizeof(struct vfs_dir_entry_t), 0);
-    memset(sb_ptr->root, 0, sizeof(struct vfs_dir_entry_t));
-
-    list_init(&sb_ptr->root->child_node_list);
-    list_init(&sb_ptr->root->subdirs_list);
+    sb_ptr->root = vfs_alloc_dentry(2);
 
     sb_ptr->root->parent = sb_ptr->root;
     sb_ptr->root->dir_ops = &fat32_dEntry_ops;
     // 分配2个字节的name
-    sb_ptr->root->name = (char *)(kmalloc(2, 0));
     sb_ptr->root->name[0] = '/';
     sb_ptr->root->name_length = 1;