block: partition: convert percpu ref

Percpu refcount is the perfect match for partition's case,
and the conversion is quite straight.

With the convertion, one pair of atomic inc/dec can be saved
for accounting block I/O, which is run in hot path of block I/O.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Ming Lei
2015-07-16 11:16:45 +08:00
committed by Jens Axboe
parent b54e5ed8f2
commit 6c71013ecb
3 changed files with 27 additions and 15 deletions
+5 -4
View File
@@ -232,8 +232,9 @@ static void delete_partition_rcu_cb(struct rcu_head *head)
put_device(part_to_dev(part));
}
void __delete_partition(struct hd_struct *part)
void __delete_partition(struct percpu_ref *ref)
{
struct hd_struct *part = container_of(ref, struct hd_struct, ref);
call_rcu(&part->rcu_head, delete_partition_rcu_cb);
}
@@ -254,7 +255,7 @@ void delete_partition(struct gendisk *disk, int partno)
kobject_put(part->holder_dir);
device_del(part_to_dev(part));
hd_struct_put(part);
hd_struct_kill(part);
}
static ssize_t whole_disk_show(struct device *dev,
@@ -355,8 +356,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
if (!dev_get_uevent_suppress(ddev))
kobject_uevent(&pdev->kobj, KOBJ_ADD);
hd_ref_init(p);
return p;
if (!hd_ref_init(p))
return p;
out_free_info:
free_part_info(p);