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authorMing Lei <tom.leiming@gmail.com>2015-07-16 06:16:45 +0300
committerJens Axboe <axboe@fb.com>2015-07-17 17:41:53 +0300
commit6c71013ecb7e2bddbed9f5b95e7aed22c491daa9 (patch)
tree773a3ebe4289815e677ce2b357c665cba5292c0e /block
parentb54e5ed8f285d62c0d242c4ef9da90937994db02 (diff)
downloadlinux-6c71013ecb7e2bddbed9f5b95e7aed22c491daa9.tar.xz
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>
Diffstat (limited to 'block')
-rw-r--r--block/genhd.c6
-rw-r--r--block/partition-generic.c9
2 files changed, 10 insertions, 5 deletions
diff --git a/block/genhd.c b/block/genhd.c
index 85df45292dba..0c706f33a599 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1284,7 +1284,11 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
* converted to make use of bd_mutex and sequence counters.
*/
seqcount_init(&disk->part0.nr_sects_seq);
- hd_ref_init(&disk->part0);
+ if (hd_ref_init(&disk->part0)) {
+ hd_free_part(&disk->part0);
+ kfree(disk);
+ return NULL;
+ }
disk->minors = minors;
rand_initialize_disk(disk);
diff --git a/block/partition-generic.c b/block/partition-generic.c
index eca0d02a607c..e7711133284e 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -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);