cfq-iosched: fix other locations where blkcg_to_cfqgd() can return NULL
Commit 9470e4a693db only covered the initial bug report, there are
other spots in CFQ where we need to check that we actually have
a valid cfq_group_data structure.
Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data")
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index ed86fb2..d8ad45ccd 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1754,6 +1754,9 @@
ret = -EINVAL;
cfqg = blkg_to_cfqg(ctx.blkg);
cfqgd = blkcg_to_cfqgd(blkcg);
+ if (!cfqg || !cfqgd)
+ goto err;
+
if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) {
if (!is_leaf_weight) {
cfqg->dev_weight = ctx.v;
@@ -1765,6 +1768,7 @@
ret = 0;
}
+err:
blkg_conf_finish(&ctx);
return ret ?: nbytes;
}
@@ -1787,12 +1791,17 @@
struct blkcg *blkcg = css_to_blkcg(css);
struct blkcg_gq *blkg;
struct cfq_group_data *cfqgd;
+ int ret = 0;
if (val < CFQ_WEIGHT_MIN || val > CFQ_WEIGHT_MAX)
return -EINVAL;
spin_lock_irq(&blkcg->lock);
cfqgd = blkcg_to_cfqgd(blkcg);
+ if (!cfqgd) {
+ ret = -EINVAL;
+ goto out;
+ }
if (!is_leaf_weight)
cfqgd->weight = val;
@@ -1814,8 +1823,9 @@
}
}
+out:
spin_unlock_irq(&blkcg->lock);
- return 0;
+ return ret;
}
static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,