Hi James,
Could you please stage this scsi_dh patch for the 3.5 merge? The other
DM mpath patches in the patchset will go through Alasdair's DM tree.
Thanks,
Mike
On Thu, May 17 2012 at 6:58pm -0400,
Chandra Seetharaman <sekharan@xxxxxxxxxx> wrote:
> Reviewed-by: Chandra Seetharaman <sekharan@xxxxxxxxxx>
>
> On Thu, 2012-05-10 at 17:31 -0400, 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>
> > Tested-by: Babu Moger <babu.moger@xxxxxxxxxx>
> > Cc: Hannes Reinecke <hare@xxxxxxx>
> > Cc: Chandra Seetharaman <sekharan@xxxxxxxxxx>
> > ---
> > drivers/scsi/device_handler/scsi_dh.c | 38 ++++++++++++++++++++++++++++++++--
> > include/scsi/scsi_dh.h | 6 +++++
> > 2 files changed, 42 insertions(+), 2 deletions(-)
> >
> > v4: fixed potential for returned string to be invalid (hch)
> > v3: fixed missing put_device that Babu pointed out
> >
> > Index: linux-2.6/drivers/scsi/device_handler/scsi_dh.c
> > ===================================================================
> > --- linux-2.6.orig/drivers/scsi/device_handler/scsi_dh.c
> > +++ linux-2.6/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 +529,38 @@ void scsi_dh_detach(struct request_queue
> > }
> > 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
> > + * @gfp - the GFP mask used in the kmalloc() call when allocating memory
> > + *
> > + * Returns name of attached handler, NULL if no handler is attached.
> > + * Caller must take care to free the returned string.
> > + */
> > +const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
> > +{
> > + unsigned long flags;
> > + struct scsi_device *sdev;
> > + const char *handler_name = NULL;
> > +
> > + 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)
> > + return NULL;
> > +
> > + if (sdev->scsi_dh_data)
> > + handler_name = kstrdup(sdev->scsi_dh_data->scsi_dh->name, gfp);
> > +
> > + put_device(&sdev->sdev_gendev);
> > + return handler_name;
> > +}
> > +EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);
> > +
> > static struct notifier_block scsi_dh_nb = {
> > .notifier_call = scsi_dh_notifier
> > };
> > Index: linux-2.6/include/scsi/scsi_dh.h
> > ===================================================================
> > --- linux-2.6.orig/include/scsi/scsi_dh.h
> > +++ linux-2.6/include/scsi/scsi_dh.h
> > @@ -60,6 +60,7 @@ extern int scsi_dh_activate(struct reque
> > 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 *, gfp_t);
> > extern int scsi_dh_set_params(struct request_queue *, const char *);
> > #else
> > static inline int scsi_dh_activate(struct request_queue *req,
> > @@ -80,6 +81,11 @@ static inline void scsi_dh_detach(struct
> > {
> > return;
> > }
> > +static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
> > + gfp_t gfp)
> > +{
> > + return NULL;
> > +}
> > static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
> > {
> > return -SCSI_DH_NOSYS;
> >
>
>
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