SUNRPC: track length of RPC wait queues

RPC wait queue length will eventually be exported to userland via the RPC
iostats interface.

Test plan:
Compile kernel with CONFIG_NFS enabled.

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 1b74420d1603..aa0449dcd8e5 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -181,6 +181,7 @@ static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *
         else
                 list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
         task->u.tk_wait.rpc_waitq = queue;
+        queue->qlen++;
         rpc_set_queued(task);
 
         dprintk("RPC: %4d added to queue %p \"%s\"\n",
@@ -215,6 +216,7 @@ static void __rpc_remove_wait_queue(struct rpc_task *task)
                 __rpc_remove_wait_queue_priority(task);
         else
                 list_del(&task->u.tk_wait.list);
+        queue->qlen--;
         dprintk("RPC: %4d removed from queue %p \"%s\"\n",
                                 task->tk_pid, queue, rpc_qname(queue));
 }