blkcg: avoid free blkcg_root when failed to alloc blkcg policy

this patch fix two errors, firstly avoid kfree blk_root, secondly not free(blkcg) ,if blkcg alloc fail(blkcg == NULL), just unlock that mutex; Signed-off-by: weiping zhang <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
leemgs · Aug 25, 2017 · 4c18c9e · 4c18c9e
1 parent 231b3db
commit 4c18c9e
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
@@ -1067,7 +1067,7 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
 		blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
 		if (!blkcg) {
 			ret = ERR_PTR(-ENOMEM);
-			goto free_blkcg;
+			goto unlock;
 		}
 	}
 
@@ -1111,8 +1111,10 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
 	for (i--; i >= 0; i--)
 		if (blkcg->cpd[i])
 			blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
-free_blkcg:
-	kfree(blkcg);
+
+	if (blkcg != &blkcg_root)
+		kfree(blkcg);
+unlock:
 	mutex_unlock(&blkcg_pol_mutex);
 	return ret;
 }