On 05/08/2012 11:56 PM, Mike Snitzer wrote:
> Introduce scsi_dh_attached_handler_name() to retrieve the name of the
> scsi_dh that is attached to the scsi_device associated with the provided
> request queue. Returns NULL if a scsi_dh is not attached.
>
> Also, fix scsi_dh_{attach,detach} function header comments to document
> @q rather than @sdev.
>
> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
> ---
> drivers/scsi/device_handler/scsi_dh.c | 31 +++++++++++++++++++++++++++++--
> include/scsi/scsi_dh.h | 5 +++++
> 2 files changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c
> index 48e46f5..7497c78 100644
> --- a/drivers/scsi/device_handler/scsi_dh.c
> +++ b/drivers/scsi/device_handler/scsi_dh.c
> @@ -468,7 +468,8 @@ EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
>
> /*
> * scsi_dh_attach - Attach device handler
> - * @sdev - sdev the handler should be attached to
> + * @q - Request queue that is associated with the scsi_device
> + * the handler should be attached to
> * @name - name of the handler to attach
> */
> int scsi_dh_attach(struct request_queue *q, const char *name)
> @@ -498,7 +499,8 @@ EXPORT_SYMBOL_GPL(scsi_dh_attach);
>
> /*
> * scsi_dh_detach - Detach device handler
> - * @sdev - sdev the handler should be detached from
> + * @q - Request queue that is associated with the scsi_device
> + * the handler should be detached from
> *
> * This function will detach the device handler only
> * if the sdev is not part of the internal list, ie
> @@ -527,6 +529,31 @@ void scsi_dh_detach(struct request_queue *q)
> }
> EXPORT_SYMBOL_GPL(scsi_dh_detach);
>
> +/*
> + * scsi_dh_attached_handler_name - Get attached device handler's name
> + * @q - Request queue that is associated with the scsi_device
> + * that may have a device handler attached
> + *
> + * Returns name of attached scsi_dh, NULL if no handler is attached.
> + */
> +const char *scsi_dh_attached_handler_name(struct request_queue *q)
> +{
> + unsigned long flags;
> + struct scsi_device *sdev;
> +
> + spin_lock_irqsave(q->queue_lock, flags);
> + sdev = q->queuedata;
> + if (!sdev || !get_device(&sdev->sdev_gendev))
> + sdev = NULL;
> + spin_unlock_irqrestore(q->queue_lock, flags);
> +
> + if (!sdev || !sdev->scsi_dh_data)
> + return NULL;
> +
> + return sdev->scsi_dh_data->scsi_dh->name;
> +}
> +EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);
> +
> static struct notifier_block scsi_dh_nb = {
> .notifier_call = scsi_dh_notifier
> };
> diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h
> index e3f2db2..94f502b 100644
> --- a/include/scsi/scsi_dh.h
> +++ b/include/scsi/scsi_dh.h
> @@ -60,6 +60,7 @@ extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
> extern int scsi_dh_handler_exist(const char *);
> extern int scsi_dh_attach(struct request_queue *, const char *);
> extern void scsi_dh_detach(struct request_queue *);
> +extern const char *scsi_dh_attached_handler_name(struct request_queue *q);
> extern int scsi_dh_set_params(struct request_queue *, const char *);
> #else
> static inline int scsi_dh_activate(struct request_queue *req,
> @@ -80,6 +81,10 @@ static inline void scsi_dh_detach(struct request_queue *q)
> {
> return;
> }
> +static inline const char *scsi_dh_attached_handler_name(struct request_queue *q)
> +{
> + return NULL;
> +}
> static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
> {
> return -SCSI_DH_NOSYS;
Acked-by: Hannes Reinecke <hare@xxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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