block: Range check cpu in blk_cpu_to_group

[net-next-2.6.git] / block / blk.h

diff --git a/block/blk.h b/block/blk.h
index 6e7dc87141e48230d0eb82c2bdcf770b0ac581a9..d6b911ac002cd9ef14c76535a6b3b6814243079b 100644 (file)
--- a/block/blk.h
+++ b/block/blk.h
@@ -142,14 +142,18 @@ static inline int queue_congestion_off_threshold(struct request_queue *q)
 
 static inline int blk_cpu_to_group(int cpu)
 {
+       int group = NR_CPUS;
 #ifdef CONFIG_SCHED_MC
        const struct cpumask *mask = cpu_coregroup_mask(cpu);
-       return cpumask_first(mask);
+       group = cpumask_first(mask);
 #elif defined(CONFIG_SCHED_SMT)
-       return cpumask_first(topology_thread_cpumask(cpu));
+       group = cpumask_first(topology_thread_cpumask(cpu));
 #else
        return cpu;
 #endif
+       if (likely(group < NR_CPUS))
+               return group;
+       return cpu;
 }
 
 /*