+-----------------------------------------------------------------------------------------+
|                               File operations structure                                 |
+-----------------------------------------------------------------------------------------+
  #include <linux/fs.h>
  struct module *owner;

  loff_t (*llseek)              | int (*check_flags)
  ssize_t (*read)               | ssize_t (*readv)
  ssize_t (*aio_read)           | ssize_t (*writev)
  ssize_t (*write)              | ssize_t (*sendfile)
  ssize_t (*aio_write)          | ssize_t (*sendpage)
  int (*readdir)                | int (*dir_notify)
  unsigned int (*poll)          | unsigned long (*get_unmapped_area)
  int (*ioctl)                  |
  int (*mmap)                   |
  int (*open)                   |
  int (*flush)                  |
  int (*release)                |
  int (*fsync)                  |
  int (*fasync)                 |
  int (*lock)                   |
+-----------------------------------------------------------------------------------------+

+-----------------------------------+-----------------------------------+
|             file struct           |          inode structure          |
+-----------------------------------+-----------------------------------+
  mode_t f_mode;                    | dev_t i_rdev;
  loff_t f_pos;                     | struct cdev *i_cdev;
  unsigned int f_flags;             |
  struct file_operations *f_op;     |
  void *private_data;               |
  struct dentry *f_dentry;          |
  struct fown_struct f_owner;       |
+-----------------------------------+-----------------------------------+


                       +-----------------------+
                       |     struct file {     |
                       |       ...             |
            +--------->|       f_op ----------+ |
            |          |       ...             | |
            |          |     }                 | |
            |          +-----------------------+ |
            |                                    |
  +---------+-------+                  v         v
  |                 |      +-----------------------+
  |  struct inode   |<-----| struct file_operations|
  |                 |<-----+       f_ops           |
  |                 |      |       ...             |
  +---------+-------+      +-----------------------+
            ^                                    ^
            |          +-----------------------+ |
            |          |      struct file      | |
            +----------|                       |-+
                       +-----------------------+