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authorJens Axboe <axboe@fb.com>2015-06-20 10:26:50 -0600
committerJens Axboe <axboe@fb.com>2015-06-20 10:26:50 -0600
commitae994ea972473c0ace9d55f718b60f0727af1381 (patch)
tree4f8f4de062db1d65af8480f2d04414b16aa2e168
parent9470e4a693db84bee7becbba8de01af02bb23c9f (diff)
downloadop-kernel-dev-ae994ea972473c0ace9d55f718b60f0727af1381.zip
op-kernel-dev-ae994ea972473c0ace9d55f718b60f0727af1381.tar.gz
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>
-rw-r--r--block/cfq-iosched.c12
1 files changed, 11 insertions, 1 deletions
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 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
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 @@ static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
ret = 0;
}
+err:
blkg_conf_finish(&ctx);
return ret ?: nbytes;
}
@@ -1787,12 +1791,17 @@ static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
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 @@ static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
}
}
+out:
spin_unlock_irq(&blkcg->lock);
- return 0;
+ return ret;
}
static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
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