sunrpc: clarify comments on rpc_make_runnable

commit 506026c3ec270e18402f0c9d33fee37482c23861 upstream.

rpc_make_runnable is not generally called with the queue lock held, unless
it's waking up a task that has been sitting on a waitqueue. This is safe
when the task has not entered the FSM yet, but the comments don't really
spell this out.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index dc6af2748e25db49f782edd275cc4549f6e596f0..150848bf717ce669ef2401aa95391150bea12792 100644 (file)
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -296,8 +296,9 @@ EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task);
 /*
  * Make an RPC task runnable.
  *
- * Note: If the task is ASYNC, this must be called with
- * the spinlock held to protect the wait queue operation.
+ * Note: If the task is ASYNC, and is being made runnable after sitting on an
+ * rpc_wait_queue, this must be called with the queue spinlock held to protect
+ * the wait queue operation.
  */
 static void rpc_make_runnable(struct rpc_task *task)
 {