1 files changed, 9 insertions, 5 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 604f6d99ab92..371fe8e92ab5 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -186,7 +186,7 @@ static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css)
 
 static inline struct blkcg *task_blkcg(struct task_struct *tsk)
 {
-        return css_to_blkcg(task_css(tsk, blkio_subsys_id));
+        return css_to_blkcg(task_css(tsk, blkio_cgrp_id));
 }
 
 static inline struct blkcg *bio_blkcg(struct bio *bio)
@@ -241,12 +241,16 @@ static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
  */
 static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
 {
-        int ret;
+        char *p;
 
-        ret = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
-        if (ret)
+        p = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
+        if (!p) {
                 strncpy(buf, "<unavailable>", buflen);
-        return ret;
+                return -ENAMETOOLONG;
+        }
+
+        memmove(buf, p, buf + buflen - p);
+        return 0;
 }
 
 /**