On Wed, Jul 08, 2015 at 01:09:44PM +0200, Hannes Reinecke wrote:
> +++ b/drivers/scsi/device_handler/scsi_dh_alua.c
> @@ -264,8 +264,11 @@ static int alua_check_vpd(struct scsi_device *sdev, 
> struct alua_dh_data *h)
>       int device_id_size, device_id_type = 0;
>       struct alua_port_group *tmp_pg, *pg = NULL;
>  
> -     if (!sdev->vpd_pg83)
> +     rcu_read_lock();
> +     if (!rcu_dereference(sdev->vpd_pg83)) {
> +             rcu_read_unlock();
>               return SCSI_DH_DEV_UNSUPP;
> +     }
>  
>       /*
>        * Look for the correct descriptor.
> @@ -281,8 +284,8 @@ static int alua_check_vpd(struct scsi_device *sdev, 
> struct alua_dh_data *h)
>        */
>       memset(device_id_str, 0, 256);
>       device_id_size = 0;
> -     d = sdev->vpd_pg83 + 4;
> -     while (d < sdev->vpd_pg83 + sdev->vpd_pg83_len) {
> +     d = rcu_dereference(sdev->vpd_pg83) + 4;
> +     while (d < rcu_dereference(sdev->vpd_pg83) + sdev->vpd_pg83_len) {

Seem like this code would benefit from a local variable in favor of the
repeated rcu_dereference() calls.

> @@ -803,7 +803,7 @@ void scsi_attach_vpd(struct scsi_device *sdev)

I think this function could use a new name, e.g. scsi_read_vpd_pages?

> @@ -563,8 +563,9 @@ static void ses_match_to_enclosure(struct 
> enclosure_device *edev,
>       if (!sdev->vpd_pg83_len)
>               return;
>  
> -     desc = sdev->vpd_pg83 + 4;
> -     while (desc < sdev->vpd_pg83 + sdev->vpd_pg83_len) {
> +     rcu_read_lock();
> +     desc = rcu_dereference(sdev->vpd_pg83) + 4;
> +     while (desc < rcu_dereference(sdev->vpd_pg83) + sdev->vpd_pg83_len) {

A local variable or two would help here as well.
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to