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>

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index faaf2b46273bbdc27ca5ec918112951f558ec313..5eb6f32df3e5467d015d64e14065b8c0b9615c56 100644 (file)
--- 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)