dm-mpath, scsi_dh: don't let dm detach device handlers

While allowing dm-mpath to attach device handlers is a functionality we need
for backwards compatibility reason there is no reason to reference count
them and detach them if dm-mpath stops using the device for some reason.

If the device handler works for the given device it can just stay attached,
and we can take the retain_hw_handler codepath.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

2 files changed, 0 insertions, 6 deletions

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 50c2a363bc8f..798d67994aeb 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -221,7 +221,6 @@ struct scsi_device_handler {
 struct scsi_dh_data {
         struct scsi_device_handler *scsi_dh;
         struct scsi_device *sdev;
-        struct kref kref;
 };
 
 #define to_scsi_device(d)       \
diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h
index 620c723ee8ed..99c9196fe606 100644
--- a/include/scsi/scsi_dh.h
+++ b/include/scsi/scsi_dh.h
@@ -59,7 +59,6 @@ enum {
 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 *, gfp_t);
 extern int scsi_dh_set_params(struct request_queue *, const char *);
 #else
@@ -77,10 +76,6 @@ static inline int scsi_dh_attach(struct request_queue *req, const char *name)
 {
         return SCSI_DH_NOSYS;
 }
-static inline void scsi_dh_detach(struct request_queue *q)
-{
-        return;
-}
 static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
                                                         gfp_t gfp)
 {