lustre/osd-ldiskfs/osd_dynlocks.h

   1 #ifndef _OSD_DYNLOCKS_H
   2 #define _OSD_DYNLOCKS_H
   3
   4 #include <linux/list.h>
   5 #include <linux/wait.h>
   6
   7 /*
   8  * lock's namespace:
   9  *   - list of locks
  10  *   - lock to protect this list
  11  */
  12 struct dynlock {
  13         unsigned                dl_magic;
  14         struct list_head        dl_list;
  15         spinlock_t              dl_list_lock;
  16 };
  17
  18 enum dynlock_type {
  19         DLT_WRITE,
  20         DLT_READ
  21 };
  22
  23 struct dynlock_handle {
  24         unsigned                dh_magic;
  25         struct list_head        dh_list;
  26         unsigned long           dh_value;       /* lock value */
  27         int                     dh_refcount;    /* number of users */
  28         int                     dh_readers;
  29         int                     dh_writers;
  30         int                     dh_pid;         /* holder of the lock */
  31         wait_queue_head_t       dh_wait;
  32 };
  33
  34 void dynlock_init(struct dynlock *dl);
  35 struct dynlock_handle *dynlock_lock(struct dynlock *dl, unsigned long value,
  36                                     enum dynlock_type lt, gfp_t gfp);
  37 void dynlock_unlock(struct dynlock *dl, struct dynlock_handle *lock);
  38 int dynlock_is_locked(struct dynlock *dl, unsigned long value);
  39
  40 #endif