cfq-iosched: fix sysfs oops when attempting to read unconfigured weights

[cascardo/linux.git] / block / cfq-iosched.c

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index dbd0207..ed86fb2 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1714,16 +1714,26 @@ static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v)
 static int cfq_print_weight(struct seq_file *sf, void *v)
 {
        struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+       struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+       unsigned int val = 0;
 
-       seq_printf(sf, "%u\n", blkcg_to_cfqgd(blkcg)->weight);
+       if (cgd)
+               val = cgd->weight;
+
+       seq_printf(sf, "%u\n", val);
        return 0;
 }
 
 static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
 {
        struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
+       struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg);
+       unsigned int val = 0;
+
+       if (cgd)
+               val = cgd->leaf_weight;
 
-       seq_printf(sf, "%u\n", blkcg_to_cfqgd(blkcg)->leaf_weight);
+       seq_printf(sf, "%u\n", val);
        return 0;
 }