From:   Trond Myklebust <trondmy@gmail.com>
To:     linux-nfs@vger.kernel.org
Subject: [PATCH v2 07/28] SUNRPC: Fix up tracking of timeouts
Date:   Fri, 29 Mar 2019 17:59:27 -0400
Message-Id: <20190329215948.107328-8-trond.myklebust@hammerspace.com>
In-Reply-To: <20190329215948.107328-7-trond.myklebust@hammerspace.com>
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Add a helper to ensure that debugfs and friends print out the
correct current task timeout value.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 include/linux/sunrpc/sched.h  |  1 +
 include/trace/events/sunrpc.h |  2 +-
 net/sunrpc/clnt.c             |  2 +-
 net/sunrpc/debugfs.c          |  2 +-
 net/sunrpc/sched.c            | 14 ++++++++++++++
 5 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index 81f5d93f7109..0b7d333f624e 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -226,6 +226,7 @@ void		rpc_execute(struct rpc_task *);
 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
+unsigned long	rpc_task_timeout(const struct rpc_task *task);
 void		rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
 					struct rpc_task *task,
 					rpc_action action,
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 5e3b77d9daa7..dd301db64521 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -186,7 +186,7 @@ DECLARE_EVENT_CLASS(rpc_task_queued,
 		__entry->client_id = task->tk_client ?
 				     task->tk_client->cl_clid : -1;
 		__entry->task_id = task->tk_pid;
-		__entry->timeout = task->tk_timeout;
+		__entry->timeout = rpc_task_timeout(task);
 		__entry->runstate = task->tk_runstate;
 		__entry->status = task->tk_status;
 		__entry->flags = task->tk_flags;
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 4d853b5420c8..3ab743c0e888 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2900,7 +2900,7 @@ static void rpc_show_task(const struct rpc_clnt *clnt,
 
 	printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
 		task->tk_pid, task->tk_flags, task->tk_status,
-		clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
+		clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
 		clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
 		task->tk_action, rpc_waitq);
 }
diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c
index 19bb356230ed..95ebd76b132d 100644
--- a/net/sunrpc/debugfs.c
+++ b/net/sunrpc/debugfs.c
@@ -33,7 +33,7 @@ tasks_show(struct seq_file *f, void *v)
 
 	seq_printf(f, "%5u %04x %6d 0x%x 0x%x %8ld %ps %sv%u %s a:%ps q:%s\n",
 		task->tk_pid, task->tk_flags, task->tk_status,
-		clnt->cl_clid, xid, task->tk_timeout, task->tk_ops,
+		clnt->cl_clid, xid, rpc_task_timeout(task), task->tk_ops,
 		clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
 		task->tk_action, rpc_waitq);
 	return 0;
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 7e0f7b83262f..40944c34a9e4 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -58,6 +58,20 @@ static struct rpc_wait_queue delay_queue;
 struct workqueue_struct *rpciod_workqueue __read_mostly;
 struct workqueue_struct *xprtiod_workqueue __read_mostly;
 
+unsigned long
+rpc_task_timeout(const struct rpc_task *task)
+{
+	unsigned long timeout = READ_ONCE(task->tk_timeout);
+
+	if (timeout != 0) {
+		unsigned long now = jiffies;
+		if (time_before(now, timeout))
+			return timeout - now;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rpc_task_timeout);
+
 /*
  * Disable the timer for a given RPC task. Should be called with
  * queue->lock and bh_disabled in order to avoid races within
-- 
2.20.1