diff options
| -rw-r--r-- | net/sunrpc/sched.c | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 385f427bedad..ff50a0546865 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -293,11 +293,6 @@ static void rpc_make_runnable(struct rpc_task *task) rpc_clear_queued(task); if (rpc_test_and_set_running(task)) return; - /* We might have raced */ - if (RPC_IS_QUEUED(task)) { - rpc_clear_running(task); - return; - } if (RPC_IS_ASYNC(task)) { int status; @@ -607,7 +602,9 @@ void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata) */ static void __rpc_execute(struct rpc_task *task) { - int status = 0; + struct rpc_wait_queue *queue; + int task_is_async = RPC_IS_ASYNC(task); + int status = 0; dprintk("RPC: %5u __rpc_execute flags=0x%x\n", task->tk_pid, task->tk_flags); @@ -647,15 +644,25 @@ static void __rpc_execute(struct rpc_task *task) */ if (!RPC_IS_QUEUED(task)) continue; - rpc_clear_running(task); - if (RPC_IS_ASYNC(task)) { - /* Careful! we may have raced... */ - if (RPC_IS_QUEUED(task)) - return; - if (rpc_test_and_set_running(task)) - return; + /* + * The queue->lock protects against races with + * rpc_make_runnable(). + * + * Note that once we clear RPC_TASK_RUNNING on an asynchronous + * rpc_task, rpc_make_runnable() can assign it to a + * different workqueue. We therefore cannot assume that the + * rpc_task pointer may still be dereferenced. + */ + queue = task->tk_waitqueue; + spin_lock_bh(&queue->lock); + if (!RPC_IS_QUEUED(task)) { + spin_unlock_bh(&queue->lock); continue; } + rpc_clear_running(task); + spin_unlock_bh(&queue->lock); + if (task_is_async) + return; /* sync task: sleep here */ dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid); |