Mastering Linux Kernel Development

Struct dentry

In our earlier discussion, we gained an understanding on how a typical disk filesystem represents each directory through an inode structure, and how a directory block on disk represents information of files under that directory. When user-mode applications initiate file access operations such as open() with a complete path such as /root/test/abc , the VFS will need to perform directory lookup operations to decode and validate each component specified in the path.

For efficient lookup and translation of components in a file path, VFS enumerates a special data structure, called dentry. A dentry object contains a string name of the file or directory, a pointer to its inode, and a pointer to the parent dentry. An instance of dentry ...