prototypes:
int (*fl_compare_owner)(struct file_lock *, struct file_lock *);
void (*fl_notify)(struct file_lock *); /* unblock callback */
- void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
void (*fl_release_private)(struct file_lock *);
void (*fl_break)(struct file_lock *); /* break_lease callback */
BKL may block
fl_compare_owner: yes no
fl_notify: yes no
-fl_copy_lock: yes no
fl_release_private: yes yes
fl_break: yes no