blkcg: remove blkcg->id
blkcg->id is a unique id given to each blkcg; however, the
cgroup_subsys_state which each blkcg embeds already has ->serial_nr
which can be used for the same purpose. Drop blkcg->id and replace
its uses with blkcg->css.serial_nr. Rename cfq_cgroup->blkcg_id to
->blkcg_serial_nr and @id in check_blkcg_changed() to @serial_nr for
consistency.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index cadc378..900f569 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -299,7 +299,7 @@
struct cfq_ttime ttime;
int ioprio; /* the current ioprio */
#ifdef CONFIG_CFQ_GROUP_IOSCHED
- uint64_t blkcg_id; /* the current blkcg ID */
+ uint64_t blkcg_serial_nr; /* the current blkcg serial */
#endif
};
@@ -3534,17 +3534,17 @@
{
struct cfq_data *cfqd = cic_to_cfqd(cic);
struct cfq_queue *sync_cfqq;
- uint64_t id;
+ uint64_t serial_nr;
rcu_read_lock();
- id = bio_blkcg(bio)->id;
+ serial_nr = bio_blkcg(bio)->css.serial_nr;
rcu_read_unlock();
/*
* Check whether blkcg has changed. The condition may trigger
* spuriously on a newly created cic but there's no harm.
*/
- if (unlikely(!cfqd) || likely(cic->blkcg_id == id))
+ if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr))
return;
sync_cfqq = cic_to_cfqq(cic, 1);
@@ -3558,7 +3558,7 @@
cfq_put_queue(sync_cfqq);
}
- cic->blkcg_id = id;
+ cic->blkcg_serial_nr = serial_nr;
}
#else
static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { }