SUNRPC: Fix broken kthread_should_stop test in svc_get_next_xprt

We should definitely not be exiting svc_get_next_xprt() with the
thread enqueued. Fix this by ensuring that we fall through to
the dequeue.
Also move the test itself outside the spin lock protected section.

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

1 files changed, 10 insertions, 21 deletions

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index faaf2b46273b..5eb6f32df3e5 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -632,7 +632,7 @@ 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;
-        long                    time_left;
+        long                    time_left = 0;
 
         /* Normally we will wait up to 5 seconds for any required
          * cache information to be provided.
@@ -665,30 +665,19 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
 
                 /* 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
-                 * 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);
-                        xprt = ERR_PTR(-EINTR);
-                        goto out;
-                }
-
                 spin_unlock_bh(&pool->sp_lock);
 
-                time_left = schedule_timeout(timeout);
-                __set_current_state(TASK_RUNNING);
+                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;
+                        xprt = rqstp->rq_xprt;
+                        if (xprt != NULL)
+                                return xprt;
+                } else
+                        __set_current_state(TASK_RUNNING);
 
                 spin_lock_bh(&pool->sp_lock);
                 if (!time_left)