lockd: don't clear sm_monitored on nsm_reboot_lookup

When lockd gets a notify downcall from statd, it'll search its hosts
cache and then clear the sm_monitored bit on the host it finds. The idea
is apparently to make lockd redo a SM_MON on the next lock request.

This is unnecessary and causes the kernel's NSM cache to go out of sync
with statd. statd doesn't stop monitoring a host when it gets a
SM_NOTIFY and there's no guarantee that another lock will occur after
the reclaim and before the unmount. In that event, no SM_UNMON will
occur.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/lockd/mon.c

@@ -349,9 +349,9 @@ retry:
  * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
  * @info: pointer to NLMPROC_SM_NOTIFY arguments
  *
- * Returns a matching nsm_handle if found in the nsm cache; the returned
+ * Returns a matching nsm_handle if found in the nsm cache. The returned
- * nsm_handle's reference count is bumped and sm_monitored is cleared.
+ * nsm_handle's reference count is bumped. Otherwise returns NULL if some
- * Otherwise returns NULL if some error occurred.
+ * error occurred.
  */
 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
 {
@@ -370,12 +370,6 @@ struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
 	atomic_inc(&cached->sm_count);
 	spin_unlock(&nsm_lock);
 
-	/*
-	 * During subsequent lock activity, force a fresh
-	 * notification to be set up for this host.
-	 */
-	cached->sm_monitored = 0;
-
 	dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
 			cached->sm_name, cached->sm_addrbuf,
 			atomic_read(&cached->sm_count));