blkcg: remove blkio_group->path[]

blkio_group->path[] stores the path of the associated cgroup and is
used only for debug messages.  Just format the path from blkg->cgroup
when printing debug messages.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 17 insertions, 4 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index ef6550a67a69..c524267e4f7f 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -77,8 +77,6 @@ struct blkio_group {
         struct list_head q_node;
         struct hlist_node blkcg_node;
         struct blkio_cgroup *blkcg;
-        /* Store cgroup path */
-        char path[128];
         /* reference count */
         int refcnt;
 
@@ -167,9 +165,24 @@ static inline struct blkio_group *pdata_to_blkg(void *pdata)
         return NULL;
 }
 
-static inline char *blkg_path(struct blkio_group *blkg)
+/**
+ * blkg_path - format cgroup path of blkg
+ * @blkg: blkg of interest
+ * @buf: target buffer
+ * @buflen: target buffer length
+ *
+ * Format the path of the cgroup of @blkg into @buf.
+ */
+static inline int blkg_path(struct blkio_group *blkg, char *buf, int buflen)
 {
-        return blkg->path;
+        int ret;
+
+        rcu_read_lock();
+        ret = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
+        rcu_read_unlock();
+        if (ret)
+                strncpy(buf, "<unavailable>", buflen);
+        return ret;
 }
 
 /**