[PATCH] knfsd: Protect update to sn_nrthreads with lock_kernel

Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/nfsd/nfsctl.c

@@ -532,7 +532,9 @@ static ssize_t write_ports(struct file *file, char *buf, size_t size)
 			/* Decrease the count, but don't shutdown the
 			 * the service
 			 */
+			lock_kernel();
 			nfsd_serv->sv_nrthreads--;
+			unlock_kernel();
 		}
 		return err;
 	}