X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=block%2Fblk-cgroup.c;h=9d359e05fad74d0a2f2a9a64ef3aeeb40bb3a7d6;hb=4e90b688013526340fef9f11ae0184888fd563d1;hp=5bcdfc10c23a6340367c4b9781496a49b5c81efe;hpb=be9e2f775f5a3147205c552534c3abf0f9374a13;p=firefly-linux-kernel-4.4.55.git

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 5bcdfc10c23a..9d359e05fad7 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1127,15 +1127,15 @@ void blkcg_exit_queue(struct request_queue *q)
  * of the main cic data structures.  For now we allow a task to change
  * its cgroup only if it's the only owner of its ioc.
  */
-static int blkcg_can_attach(struct cgroup_subsys_state *css,
-			    struct cgroup_taskset *tset)
+static int blkcg_can_attach(struct cgroup_taskset *tset)
 {
 	struct task_struct *task;
+	struct cgroup_subsys_state *dst_css;
 	struct io_context *ioc;
 	int ret = 0;
 
 	/* task_lock() is needed to avoid races with exit_io_context() */
-	cgroup_taskset_for_each(task, tset) {
+	cgroup_taskset_for_each(task, dst_css, tset) {
 		task_lock(task);
 		ioc = task->io_context;
 		if (ioc && atomic_read(&ioc->nr_tasks) > 1)
@@ -1331,10 +1331,8 @@ int blkcg_policy_register(struct blkcg_policy *pol)
 			struct blkcg_policy_data *cpd;
 
 			cpd = pol->cpd_alloc_fn(GFP_KERNEL);
-			if (!cpd) {
-				mutex_unlock(&blkcg_pol_mutex);
+			if (!cpd)
 				goto err_free_cpds;
-			}
 
 			blkcg->cpd[pol->plid] = cpd;
 			cpd->blkcg = blkcg;