From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH v2 2/5] scsi_dh: add scsi_dh_attached_handler_name Date: Wed, 09 May 2012 08:57:53 +0200 Message-ID: <4FAA1571.4090007@suse.de> References: <1336514167-15393-1-git-send-email-snitzer@redhat.com> <1336514167-15393-3-git-send-email-snitzer@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1336514167-15393-3-git-send-email-snitzer@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mike Snitzer Cc: dm-devel@redhat.com, babu.moger@netapp.com, agk@redhat.com List-Id: dm-devel.ids 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 > --- > 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 =3D q->queuedata; > + if (!sdev || !get_device(&sdev->sdev_gendev)) > + sdev =3D 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 =3D { > .notifier_call =3D 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 *, act= ivate_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_q= ueue *q) > +{ > + return NULL; > +} > static inline int scsi_dh_set_params(struct request_queue *req, const ch= ar *params) > { > return -SCSI_DH_NOSYS; Acked-by: Hannes Reinecke Cheers, Hannes -- = Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg)