diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c index 53a7385e1b4d..3ee1cbc89479 100644 --- a/drivers/scsi/device_handler/scsi_dh.c +++ b/drivers/scsi/device_handler/scsi_dh.c @@ -451,6 +451,39 @@ int scsi_dh_activate(struct request_queue *q) } EXPORT_SYMBOL_GPL(scsi_dh_activate); +/* + * scsi_dh_set_params - set the parameters for the device as per the + * string specified in params. + * @q - Request queue that is associated with the scsi_device for + * which the parameters to be set. + * @params - parameters in the following format + * "no_of_params\0param1\0param2\0param3\0...\0" + * for example, string for 2 parameters with value 10 and 21 + * is specified as "2\010\021\0". + */ +int scsi_dh_set_params(struct request_queue *q, const char *params) +{ + int err = -SCSI_DH_NOSYS; + unsigned long flags; + struct scsi_device *sdev; + struct scsi_device_handler *scsi_dh = NULL; + + spin_lock_irqsave(q->queue_lock, flags); + sdev = q->queuedata; + if (sdev && sdev->scsi_dh_data) + scsi_dh = sdev->scsi_dh_data->scsi_dh; + if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) + err = 0; + spin_unlock_irqrestore(q->queue_lock, flags); + + if (err) + return err; + err = scsi_dh->set_params(sdev, params); + put_device(&sdev->sdev_gendev); + return err; +} +EXPORT_SYMBOL_GPL(scsi_dh_set_params); + /* * scsi_dh_handler_exist - Return TRUE(1) if a device handler exists for * the given name. FALSE(0) otherwise. diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 1f3a4c8044c0..9af48cbf0036 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -187,6 +187,7 @@ struct scsi_device_handler { void (*detach)(struct scsi_device *); int (*activate)(struct scsi_device *); int (*prep_fn)(struct scsi_device *, struct request *); + int (*set_params)(struct scsi_device *, const char *); }; struct scsi_dh_data { diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h index 33efce20c26c..ff2407405b42 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 *); 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 int scsi_dh_set_params(struct request_queue *, const char *); #else static inline int scsi_dh_activate(struct request_queue *req) { @@ -77,4 +78,8 @@ static inline void scsi_dh_detach(struct request_queue *q) { return; } +static inline int scsi_dh_set_params(struct request_queue *req, const char *params) +{ + return -SCSI_DH_NOSYS; +} #endif