On 05/03/2016 03:38 PM, Johannes Thumshirn wrote:
> Inititialize the hd_struct's perpcu reference before assigning the hd_struct
> to the partition table list.
> 
> This fixes a race which could be triggered using a simple partition
> creation/deletion loop with virtio-blk on aarch64.
> 
> Signed-off-by: Johannes Thumshirn <jthumsh...@suse.de>
> ---
>  block/partition-generic.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/block/partition-generic.c b/block/partition-generic.c
> index 5d87019..aa5b83a 100644
> --- a/block/partition-generic.c
> +++ b/block/partition-generic.c
> @@ -361,6 +361,10 @@ struct hd_struct *add_partition(struct gendisk *disk, 
> int partno,
>                       goto out_del;
>       }
>  
> +     err = -ENOMEM;
> +     if (hd_ref_init(p))
> +             goto out_free_info;
> +
>       /* everything is up and running, commence */
>       rcu_assign_pointer(ptbl->part[partno], p);
>  
> @@ -368,8 +372,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int 
> partno,
>       if (!dev_get_uevent_suppress(ddev))
>               kobject_uevent(&pdev->kobj, KOBJ_ADD);
>  
> -     if (!hd_ref_init(p))
> -             return p;
> +     return p;
>  
>  out_free_info:
>       free_part_info(p);
> 
Suggested-by: Hannes Reinecke <h...@suse.com>
Reviewed-by: Hannes Reinecke <h...@suse.com>

:-)

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Teamlead Storage & Networking
h...@suse.de                                   +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)

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