[PATCH] NFS: Fix Oops in rpc_call_sync()

Fix the Oops in http://bugzilla.linux-nfs.org/show_bug.cgi?id=138
We shouldn't be calling rpc_release_task() for tasks that are not active.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/sunrpc/sched.h

@@ -250,7 +250,6 @@ void		rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt,
 				int flags, const struct rpc_call_ops *ops,
 				void *data);
 void		rpc_put_task(struct rpc_task *);
-void		rpc_release_task(struct rpc_task *);
 void		rpc_exit_task(struct rpc_task *);
 void		rpc_release_calldata(const struct rpc_call_ops *, void *);
 void		rpc_killall_tasks(struct rpc_clnt *);

net/sunrpc/clnt.c

@@ -490,16 +490,14 @@ int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 
 	/* Set up the call info struct and execute the task */
 	status = task->tk_status;
-	if (status != 0) {
-		rpc_release_task(task);
+	if (status != 0)
 		goto out;
-	}
 	atomic_inc(&task->tk_count);
 	status = rpc_execute(task);
 	if (status == 0)
 		status = task->tk_status;
-	rpc_put_task(task);
 out:
+	rpc_put_task(task);
 	rpc_restore_sigmask(&oldset);
 	return status;
 }
@@ -537,7 +535,7 @@ rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 	if (status == 0)
 		rpc_execute(task);
 	else
-		rpc_release_task(task);
+		rpc_put_task(task);
 
 	rpc_restore_sigmask(&oldset);		
 	return status;

net/sunrpc/sched.c

@@ -42,6 +42,7 @@ static mempool_t	*rpc_buffer_mempool __read_mostly;
 static void			__rpc_default_timer(struct rpc_task *task);
 static void			rpciod_killall(void);
 static void			rpc_async_schedule(struct work_struct *);
+static void			 rpc_release_task(struct rpc_task *task);
 
 /*
  * RPC tasks sit here while waiting for conditions to improve.
@@ -896,7 +897,7 @@ void rpc_put_task(struct rpc_task *task)
 }
 EXPORT_SYMBOL(rpc_put_task);
 
-void rpc_release_task(struct rpc_task *task)
+static void rpc_release_task(struct rpc_task *task)
 {
 #ifdef RPC_DEBUG
 	BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);