diff options
| -rw-r--r-- | include/sys/condvar.h | 3 | ||||
| -rw-r--r-- | module/spl/spl-condvar.c | 32 |
2 files changed, 26 insertions, 9 deletions
diff --git a/include/sys/condvar.h b/include/sys/condvar.h index 59407c2dd..709a86d39 100644 --- a/include/sys/condvar.h +++ b/include/sys/condvar.h @@ -35,12 +35,13 @@ * calling any of the wait/signal funs, and passed into the wait funs. */ #define CV_MAGIC 0x346545f4 -#define CV_POISON 0x95 +#define CV_DESTROY 0x346545f5 typedef struct { int cv_magic; wait_queue_head_t cv_event; wait_queue_head_t cv_destroy; + atomic_t cv_refs; atomic_t cv_waiters; kmutex_t *cv_mutex; } kcondvar_t; diff --git a/module/spl/spl-condvar.c b/module/spl/spl-condvar.c index e9f727d72..6ed6579b3 100644 --- a/module/spl/spl-condvar.c +++ b/module/spl/spl-condvar.c @@ -48,6 +48,7 @@ __cv_init(kcondvar_t *cvp, char *name, kcv_type_t type, void *arg) init_waitqueue_head(&cvp->cv_event); init_waitqueue_head(&cvp->cv_destroy); atomic_set(&cvp->cv_waiters, 0); + atomic_set(&cvp->cv_refs, 1); cvp->cv_mutex = NULL; /* We may be called when there is a non-zero preempt_count or @@ -63,12 +64,13 @@ EXPORT_SYMBOL(__cv_init); static int cv_destroy_wakeup(kcondvar_t *cvp) { - if ((cvp->cv_mutex != NULL) || - (waitqueue_active(&cvp->cv_event)) || - (atomic_read(&cvp->cv_waiters) > 0)) - return 0; + if (!atomic_read(&cvp->cv_waiters) && !atomic_read(&cvp->cv_refs)) { + ASSERT(cvp->cv_mutex == NULL); + ASSERT(!waitqueue_active(&cvp->cv_event)); + return 1; + } - return 1; + return 0; } void @@ -78,11 +80,15 @@ __cv_destroy(kcondvar_t *cvp) ASSERT(cvp); ASSERT(cvp->cv_magic == CV_MAGIC); - /* Block until all waiters have woken */ + cvp->cv_magic = CV_DESTROY; + atomic_dec(&cvp->cv_refs); + + /* Block until all waiters are woken and references dropped. */ while (cv_destroy_wakeup(cvp) == 0) wait_event_timeout(cvp->cv_destroy, cv_destroy_wakeup(cvp), 1); ASSERT3P(cvp->cv_mutex, ==, NULL); + ASSERT3S(atomic_read(&cvp->cv_refs), ==, 0); ASSERT3S(atomic_read(&cvp->cv_waiters), ==, 0); ASSERT3S(waitqueue_active(&cvp->cv_event), ==, 0); @@ -100,6 +106,7 @@ cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state) ASSERT(mp); ASSERT(cvp->cv_magic == CV_MAGIC); ASSERT(mutex_owned(mp)); + atomic_inc(&cvp->cv_refs); if (cvp->cv_mutex == NULL) cvp->cv_mutex = mp; @@ -124,6 +131,7 @@ cv_wait_common(kcondvar_t *cvp, kmutex_t *mp, int state) } finish_wait(&cvp->cv_event, &wait); + atomic_dec(&cvp->cv_refs); SEXIT; } @@ -157,6 +165,7 @@ __cv_timedwait_common(kcondvar_t *cvp, kmutex_t *mp, ASSERT(mp); ASSERT(cvp->cv_magic == CV_MAGIC); ASSERT(mutex_owned(mp)); + atomic_inc(&cvp->cv_refs); if (cvp->cv_mutex == NULL) cvp->cv_mutex = mp; @@ -166,8 +175,10 @@ __cv_timedwait_common(kcondvar_t *cvp, kmutex_t *mp, /* XXX - Does not handle jiffie wrap properly */ time_left = expire_time - jiffies; - if (time_left <= 0) + if (time_left <= 0) { + atomic_dec(&cvp->cv_refs); SRETURN(-1); + } prepare_to_wait_exclusive(&cvp->cv_event, &wait, state); atomic_inc(&cvp->cv_waiters); @@ -186,6 +197,7 @@ __cv_timedwait_common(kcondvar_t *cvp, kmutex_t *mp, } finish_wait(&cvp->cv_event, &wait); + atomic_dec(&cvp->cv_refs); SRETURN(time_left > 0 ? time_left : -1); } @@ -210,6 +222,7 @@ __cv_signal(kcondvar_t *cvp) SENTRY; ASSERT(cvp); ASSERT(cvp->cv_magic == CV_MAGIC); + atomic_inc(&cvp->cv_refs); /* All waiters are added with WQ_FLAG_EXCLUSIVE so only one * waiter will be set runable with each call to wake_up(). @@ -218,6 +231,7 @@ __cv_signal(kcondvar_t *cvp) if (atomic_read(&cvp->cv_waiters) > 0) wake_up(&cvp->cv_event); + atomic_dec(&cvp->cv_refs); SEXIT; } EXPORT_SYMBOL(__cv_signal); @@ -225,15 +239,17 @@ EXPORT_SYMBOL(__cv_signal); void __cv_broadcast(kcondvar_t *cvp) { + SENTRY; ASSERT(cvp); ASSERT(cvp->cv_magic == CV_MAGIC); - SENTRY; + atomic_inc(&cvp->cv_refs); /* Wake_up_all() will wake up all waiters even those which * have the WQ_FLAG_EXCLUSIVE flag set. */ if (atomic_read(&cvp->cv_waiters) > 0) wake_up_all(&cvp->cv_event); + atomic_dec(&cvp->cv_refs); SEXIT; } EXPORT_SYMBOL(__cv_broadcast); |