Mastering Linux Kernel Development

struct file

An instance of struct file represents an open file. This structure is created when a user process successfully opens a file, and contains the caller application's file access attributes such as offset into file data, access mode, and special flags, among others. This object is mapped to the caller's file descriptor table, and serves as the caller application's handle to the file. This structure is local to the process and is retained by a process until the relevant file is closed. A close operation on the file descriptor destroys the file instance.

struct file {       union {           struct llist_node       fu_llist;         struct rcu_head         fu_rcuhead;       } f_u;    struct path             f_path;   struct inode            *f_inode;       /* cached value */ const struct file_operations *f_op; ...