diff options
| -rw-r--r-- | include/linux/sunrpc/svc.h | 1 | ||||
| -rw-r--r-- | net/sunrpc/svc.c | 2 | ||||
| -rw-r--r-- | net/sunrpc/svc_xprt.c | 32 |
3 files changed, 17 insertions, 18 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index cf61ecd148e0..21678464883a 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -280,7 +280,6 @@ struct svc_rqst { bool rq_splice_ok; /* turned off in gss privacy * to prevent encrypting page * cache pages */ - wait_queue_head_t rq_wait; /* synchronization */ struct task_struct *rq_task; /* service thread */ }; diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 1db5007ddbce..ca8a7958f4e6 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -612,8 +612,6 @@ svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node) if (!rqstp) goto out_enomem; - init_waitqueue_head(&rqstp->rq_wait); - serv->sv_nrthreads++; spin_lock_bh(&pool->sp_lock); pool->sp_nrthreads++; diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 08e49d1e17b3..faaf2b46273b 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -348,8 +348,6 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) cpu = get_cpu(); pool = svc_pool_for_cpu(xprt->xpt_server, cpu); - put_cpu(); - spin_lock_bh(&pool->sp_lock); if (!list_empty(&pool->sp_threads) && @@ -382,10 +380,15 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) printk(KERN_ERR "svc_xprt_enqueue: server %p, rq_xprt=%p!\n", rqstp, rqstp->rq_xprt); - rqstp->rq_xprt = xprt; + /* Note the order of the following 3 lines: + * We want to assign xprt to rqstp->rq_xprt only _after_ + * we've woken up the process, so that we don't race with + * the lockless check in svc_get_next_xprt(). + */ svc_xprt_get(xprt); + wake_up_process(rqstp->rq_task); + rqstp->rq_xprt = xprt; pool->sp_stats.threads_woken++; - wake_up(&rqstp->rq_wait); } else { dprintk("svc: transport %p put into queue\n", xprt); list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); @@ -394,6 +397,7 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt) out_unlock: spin_unlock_bh(&pool->sp_lock); + put_cpu(); } /* @@ -509,7 +513,7 @@ void svc_wake_up(struct svc_serv *serv) svc_thread_dequeue(pool, rqstp); rqstp->rq_xprt = NULL; */ - wake_up(&rqstp->rq_wait); + wake_up_process(rqstp->rq_task); } else pool->sp_task_pending = 1; spin_unlock_bh(&pool->sp_lock); @@ -628,7 +632,6 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) { struct svc_xprt *xprt; struct svc_pool *pool = rqstp->rq_pool; - DECLARE_WAITQUEUE(wait, current); long time_left; /* Normally we will wait up to 5 seconds for any required @@ -654,15 +657,15 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) xprt = ERR_PTR(-EAGAIN); goto out; } - /* No data pending. Go to sleep */ - svc_thread_enqueue(pool, rqstp); - /* * We have to be able to interrupt this wait * to bring down the daemons ... */ set_current_state(TASK_INTERRUPTIBLE); + /* No data pending. Go to sleep */ + svc_thread_enqueue(pool, rqstp); + /* * checking kthread_should_stop() here allows us to avoid * locking and signalling when stopping kthreads that call @@ -676,14 +679,13 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) goto out; } - add_wait_queue(&rqstp->rq_wait, &wait); spin_unlock_bh(&pool->sp_lock); time_left = schedule_timeout(timeout); + __set_current_state(TASK_RUNNING); try_to_freeze(); - remove_wait_queue(&rqstp->rq_wait, &wait); xprt = rqstp->rq_xprt; if (xprt != NULL) return xprt; @@ -786,10 +788,10 @@ int svc_recv(struct svc_rqst *rqstp, long timeout) printk(KERN_ERR "svc_recv: service %p, transport not NULL!\n", rqstp); - if (waitqueue_active(&rqstp->rq_wait)) - printk(KERN_ERR - "svc_recv: service %p, wait queue active!\n", - rqstp); + + /* Make sure the task pointer is set! */ + if (WARN_ON_ONCE(!rqstp->rq_task)) + rqstp->rq_task = current_task; err = svc_alloc_arg(rqstp); if (err) |