850bac3ae4
Refactor: Extract the loop that finds an idle service thread from svc_xprt_enqueue() and svc_wake_up(). Both functions do just about the same thing. Note that svc_wake_up() currently does not hold the RCU read lock while waking the target thread. It indeed should hold the lock, just as svc_xprt_enqueue() does, to ensure the rqstp does not vanish during the wake-up. This patch adds the RCU lock for svc_wake_up(). Note that shrinking the pool thread count is rare, and calls to svc_wake_up() are also quite infrequent. In practice, this race is very unlikely to be hit, so we are not marking the lock fix for stable backport at this time. Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>