On Tue, 10 Jun 2008 16:33:32 -0400 Trond Myklebust <trond.myklebust@xxxxxxxxxx> wrote: > On Tue, 2008-06-10 at 16:13 -0400, Jeff Layton wrote: > > > We can't call nfs_callback_down() until after nfs_callback_up() > > returns, so we're guaranteed to have "task" set to a valid task > > (presuming that nfs_callback_up() doesn't return error). We also can't > > return from nfs_callback_down() until after the nfs_callback_svc() has > > exited. kthread_stop() will block until it does. > > The code I'm alluding to is in kthread(): > > /* OK, tell user we're spawned, wait for stop or wakeup */ > __set_current_state(TASK_UNINTERRUPTIBLE); > complete(&create->started); > schedule(); > > if (!kthread_should_stop()) > ret = threadfn(data); > > schedule() is called _after_ the complete() call, and _before_ we > execute threadfn() a.k.a. nfs_callback_svc(). If nfs_alloc_client() has > time to call nfs_callback_down() before the above thread gets scheduled > back in, then threadfn() doesn't get called at all, since > kthread_should_stop() is true. > That makes total sense. Thanks for clearing it up. Cheers, -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
