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Diffstat (limited to 'net/sunrpc/svc_xprt.c')
-rw-r--r--net/sunrpc/svc_xprt.c81
1 files changed, 33 insertions, 48 deletions
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 6666c674585..c179ca2a5aa 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -346,20 +346,6 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt)
if (!svc_xprt_has_something_to_do(xprt))
return;
- 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) &&
- !list_empty(&pool->sp_sockets))
- printk(KERN_ERR
- "svc_xprt_enqueue: "
- "threads and transports both waiting??\n");
-
- pool->sp_stats.packets++;
-
/* Mark transport as busy. It will remain in this state until
* the provider calls svc_xprt_received. We update XPT_BUSY
* atomically because it also guards against trying to enqueue
@@ -368,9 +354,15 @@ static void svc_xprt_do_enqueue(struct svc_xprt *xprt)
if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
/* Don't enqueue transport while already enqueued */
dprintk("svc: transport %p busy, not enqueued\n", xprt);
- goto out_unlock;
+ return;
}
+ cpu = get_cpu();
+ pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
+ spin_lock_bh(&pool->sp_lock);
+
+ pool->sp_stats.packets++;
+
if (!list_empty(&pool->sp_threads)) {
rqstp = list_entry(pool->sp_threads.next,
struct svc_rqst,
@@ -382,18 +374,23 @@ 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);
pool->sp_stats.sockets_queued++;
}
-out_unlock:
spin_unlock_bh(&pool->sp_lock);
+ put_cpu();
}
/*
@@ -509,7 +506,7 @@ 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);
@@ -628,8 +625,7 @@ 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;
+ long time_left = 0;
/* Normally we will wait up to 5 seconds for any required
* cache information to be provided.
@@ -651,40 +647,32 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
} else {
if (pool->sp_task_pending) {
pool->sp_task_pending = 0;
- spin_unlock_bh(&pool->sp_lock);
- return ERR_PTR(-EAGAIN);
+ 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);
- /*
- * checking kthread_should_stop() here allows us to avoid
- * locking and signalling when stopping kthreads that call
- * svc_recv. If the thread has already been woken up, then
- * we can exit here without sleeping. If not, then it
- * it'll be woken up quickly during the schedule_timeout
- */
- if (kthread_should_stop()) {
- set_current_state(TASK_RUNNING);
- spin_unlock_bh(&pool->sp_lock);
- return ERR_PTR(-EINTR);
- }
-
- add_wait_queue(&rqstp->rq_wait, &wait);
+ /* No data pending. Go to sleep */
+ svc_thread_enqueue(pool, rqstp);
spin_unlock_bh(&pool->sp_lock);
- time_left = schedule_timeout(timeout);
+ if (!(signalled() || kthread_should_stop())) {
+ time_left = schedule_timeout(timeout);
+ __set_current_state(TASK_RUNNING);
- try_to_freeze();
+ try_to_freeze();
+
+ xprt = rqstp->rq_xprt;
+ if (xprt != NULL)
+ return xprt;
+ } else
+ __set_current_state(TASK_RUNNING);
spin_lock_bh(&pool->sp_lock);
- remove_wait_queue(&rqstp->rq_wait, &wait);
if (!time_left)
pool->sp_stats.threads_timedout++;
@@ -699,6 +687,7 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
return ERR_PTR(-EAGAIN);
}
}
+out:
spin_unlock_bh(&pool->sp_lock);
return xprt;
}
@@ -744,7 +733,7 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
svc_add_new_temp_xprt(serv, newxpt);
else
module_put(xprt->xpt_class->xcl_owner);
- } else if (xprt->xpt_ops->xpo_has_wspace(xprt)) {
+ } else {
/* XPT_DATA|XPT_DEFERRED case: */
dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
rqstp, rqstp->rq_pool->sp_id, xprt,
@@ -781,10 +770,6 @@ 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);
err = svc_alloc_arg(rqstp);
if (err)