Block in cv_destroy() on all waiters

[mirror_spl.git] / module / spl / spl-condvar.c

diff --git a/module/spl/spl-condvar.c b/module/spl/spl-condvar.c
index 421f8806b006285facbb462af41ca89fd5d7dc50..2730435c75aa163a49b97c968c463d375d9bde23 100644 (file)
--- a/module/spl/spl-condvar.c
+++ b/module/spl/spl-condvar.c
@@ -46,6 +46,7 @@ __cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg)
 
        cvp->cv_magic = CV_MAGIC;
        init_waitqueue_head(&cvp->cv_event);
+       init_waitqueue_head(&cvp->cv_destroy);
        atomic_set(&cvp->cv_waiters, 0);
        cvp->cv_mutex = NULL;
        cvp->cv_name = NULL;
@@ -65,12 +66,27 @@ __cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg)
 }
 EXPORT_SYMBOL(__cv_init);
 
+static int
+cv_destroy_wakeup(kcondvar_t *cvp)
+{
+       if ((waitqueue_active(&cvp->cv_event)) ||
+           (atomic_read(&cvp->cv_waiters) > 0))
+               return 0;
+
+       return 1;
+}
+
 void
 __cv_destroy(kcondvar_t *cvp)
 {
        SENTRY;
        ASSERT(cvp);
        ASSERT(cvp->cv_magic == CV_MAGIC);
+
+       /* Block until all waiters have woken */
+       while (cv_destroy_wakeup(cvp) == 0)
+               wait_event_timeout(cvp->cv_destroy, cv_destroy_wakeup(cvp), 1);
+
        ASSERT(cvp->cv_mutex == NULL);
        ASSERT(atomic_read(&cvp->cv_waiters) == 0);
        ASSERT(!waitqueue_active(&cvp->cv_event));
@@ -78,7 +94,6 @@ __cv_destroy(kcondvar_t *cvp)
        if (cvp->cv_name)
                kmem_free(cvp->cv_name, cvp->cv_name_size);
 
-       ASSERT3P(memset(cvp, CV_POISON, sizeof(*cvp)), ==, cvp);
        SEXIT;
 }
 EXPORT_SYMBOL(__cv_destroy);
@@ -111,10 +126,13 @@ cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state)
        mutex_enter(mp);
 
        /* No more waiters a different mutex could be used */
-       if (atomic_dec_and_test(&cvp->cv_waiters))
+       if (atomic_dec_and_test(&cvp->cv_waiters)) {
                cvp->cv_mutex = NULL;
+               wake_up(&cvp->cv_destroy);
+       }
 
        finish_wait(&cvp->cv_event, &wait);
+
        SEXIT;
 }
 
@@ -170,8 +188,10 @@ __cv_timedwait_common(kcondvar_t *cvp, kmutex_t *mp,
        mutex_enter(mp);
 
        /* No more waiters a different mutex could be used */
-       if (atomic_dec_and_test(&cvp->cv_waiters))
+       if (atomic_dec_and_test(&cvp->cv_waiters)) {
                cvp->cv_mutex = NULL;
+               wake_up(&cvp->cv_destroy);
+       }
 
        finish_wait(&cvp->cv_event, &wait);