On Tue, 2008-06-10 at 15:13 -0400, Jeff Layton wrote: > I think you're basically correct, but it looks to me like the > nfs_callback_mutex actually protects nfs_callback_info.task as well. > > If we're starting the thread, then we can't call kthread_stop on it > until we release the mutex. So the thread can't exit until we release > the mutex, and we can be guaranteed that this: > > nfs_callback_info.task = NULL; > > ...can't happen until after kthread_run returns and nfs_callback_up > sets it. > > If that's right, then maybe this (untested, RFC only) patch would make sense? Hmm... I suppose that is correct, but what if nfs_alloc_client() does nfs_callback_up(); <kstrdup() fails> nfs_callback_down(); AFAICS, if nfs_callback_down() gets called before the kthread() function gets scheduled back in, then you can get left with a value of nfs_callback_info.task != NULL, since nfs_callback_svc() will never be called. Wouldn't it therefore make more sense to clear nfs_callback_info.task in nfs_callback_down()? Cheers Trond -- 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
