On Wed, 9 Jan 2008 18:48:14 +0000 Christoph Hellwig <[EMAIL PROTECTED]> wrote:
> On Wed, Jan 09, 2008 at 01:36:21PM -0500, Jeff Layton wrote: > > I don't see a good alternative though. We need to be able to drop > > the and check the refcount in nlmsvc_unlink_block. That function is > > called from lockd, and we can't have lockd call kthread_stop on > > itself. > > > > If you see a better way to do this, I'm certainly open to > > suggestions. > > > > I'll note that my first stab at fixing this problem was to change > > the svc_wake_up() call in the rpc callback to a routine to wake up > > any lockd on the box that happened to be up. That sidesteps this > > entire problem of having to make sure lockd stays up. If we decided > > that was the right approach we could dump the last patch in this > > series altogether. > > > > That said there could be other use after free bugs lurking in the > > lockd code so maybe keeping lockd up until nlm_blocked is empty is > > the right thing to do. > > What about just not exiting from lockd as long as nlm_blocked is not > empty? lockd_down still simply calls kthread_stop, but lockd only > honours it when nlm_blocked is empty? lockd can basically block forever in this situation if the client goes away for good. With the current kthread implementation, kthread_stops are serialized and I don't think we want to monopolize the kthread_stop queue. If kthread_stops could occur in parallel, that would be a different situation :-) -- Jeff Layton <[EMAIL PROTECTED]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
