Several improvements to rmlock(9). Many of these are based on patches

provided by Isilon.
- Add an rm_assert() supporting various lock assertions similar to other
  locking primitives.  Because rmlocks track readers the assertions are
  always fully accurate unlike rw_assert() and sx_assert().
- Flesh out the lock class methods for rmlocks to support sleeping via
  condvars and rm_sleep() (but only while holding write locks), rmlock
  details in 'show lock' in DDB, and the lc_owner method used by
  dtrace.
- Add an internal destroyed cookie so that API functions can assert
  that an rmlock is not destroyed.
- Make use of rm_assert() to add various assertions to the API (e.g.
  to assert locks are held when an unlock routine is called).
- Give RM_SLEEPABLE locks their own lock class and always use the
  rmlock's own lock_object with WITNESS.
- Use THREAD_NO_SLEEPING() / THREAD_SLEEPING_OK() to disallow sleeping
  while holding a read lock on an rmlock.

Submitted by:	andre
Obtained from:	EMC/Isilon

1 files changed, 22 insertions, 0 deletions

diff --git a/sys/sys/rmlock.h b/sys/sys/rmlock.h
index 5a0fa8a..ed6110a 100644
--- a/sys/sys/rmlock.h
+++ b/sys/sys/rmlock.h
@@ -65,6 +65,10 @@ void	_rm_wunlock(struct rmlock *rm);
 int	_rm_rlock(struct rmlock *rm, struct rm_priotracker *tracker,
 	    int trylock);
 void	_rm_runlock(struct rmlock *rm,  struct rm_priotracker *tracker);
+#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
+void	_rm_assert(const struct rmlock *rm, int what, const char *file,
+	    int line);
+#endif
 
 /*
  * Public interface for lock operations.
@@ -89,6 +93,9 @@ void	_rm_runlock(struct rmlock *rm,  struct rm_priotracker *tracker);
 #define	rm_try_rlock(rm,tracker)	_rm_rlock((rm),(tracker), 1)
 #define	rm_runlock(rm,tracker)		_rm_runlock((rm), (tracker))
 #endif
+#define	rm_sleep(chan, rm, pri, wmesg, timo)				\
+	_sleep((chan), &(rm)->lock_object, (pri), (wmesg),		\
+	    tick_sbt * (timo), 0, C_HARDCLOCK)
 
 struct rm_args {
 	struct rmlock	*ra_rm;
@@ -123,5 +130,20 @@ struct rm_args_flags {
 	SYSUNINIT(name##_rm_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
 	    rm_destroy, (rm))
 
+#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
+#define	RA_LOCKED		LA_LOCKED
+#define	RA_RLOCKED		LA_SLOCKED
+#define	RA_WLOCKED		LA_XLOCKED
+#define	RA_UNLOCKED		LA_UNLOCKED
+#define	RA_RECURSED		LA_RECURSED
+#define	RA_NOTRECURSED		LA_NOTRECURSED
+#endif
+
+#ifdef INVARIANTS
+#define	rm_assert(rm, what)	_rm_assert((rm), (what), LOCK_FILE, LOCK_LINE)
+#else
+#define	rm_assert(rm, what)
+#endif
+
 #endif /* _KERNEL */
 #endif /* !_SYS_RMLOCK_H_ */