SUNRPC: Do not grab pool->sp_lock unnecessarily in svc_get_next_xprt

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 08e48cecfdcc..08e49d1e17b3 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -651,8 +651,8 @@ 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);
@@ -672,8 +672,8 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
                  */
                 if (kthread_should_stop()) {
                         set_current_state(TASK_RUNNING);
-                        spin_unlock_bh(&pool->sp_lock);
-                        return ERR_PTR(-EINTR);
+                        xprt = ERR_PTR(-EINTR);
+                        goto out;
                 }
 
                 add_wait_queue(&rqstp->rq_wait, &wait);
@@ -683,8 +683,12 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
 
                 try_to_freeze();
 
-                spin_lock_bh(&pool->sp_lock);
                 remove_wait_queue(&rqstp->rq_wait, &wait);
+                xprt = rqstp->rq_xprt;
+                if (xprt != NULL)
+                        return xprt;
+
+                spin_lock_bh(&pool->sp_lock);
                 if (!time_left)
                         pool->sp_stats.threads_timedout++;
 
@@ -699,6 +703,7 @@ 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;
 }