4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hannes Reinecke <hare@xxxxxxx> commit 857de6e00778738dc3d61f75acbac35bdc48e533 upstream. The device handler needs to check if a given queue belongs to a scsi device; only then does it make sense to attach a device handler. [mkp: dropped flags] Signed-off-by: Hannes Reinecke <hare@xxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/scsi_dh.c | 22 ++++------------------ drivers/scsi/scsi_lib.c | 23 +++++++++++++++++++++++ include/scsi/scsi_device.h | 1 + 3 files changed, 28 insertions(+), 18 deletions(-) --- a/drivers/scsi/scsi_dh.c +++ b/drivers/scsi/scsi_dh.c @@ -289,20 +289,6 @@ int scsi_unregister_device_handler(struc } EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); -static struct scsi_device *get_sdev_from_queue(struct request_queue *q) -{ - struct scsi_device *sdev; - unsigned long flags; - - 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); - - return sdev; -} - /* * scsi_dh_activate - activate the path associated with the scsi_device * corresponding to the given request queue. @@ -321,7 +307,7 @@ int scsi_dh_activate(struct request_queu struct scsi_device *sdev; int err = SCSI_DH_NOSYS; - sdev = get_sdev_from_queue(q); + sdev = scsi_device_from_queue(q); if (!sdev) { if (fn) fn(data, err); @@ -368,7 +354,7 @@ int scsi_dh_set_params(struct request_qu struct scsi_device *sdev; int err = -SCSI_DH_NOSYS; - sdev = get_sdev_from_queue(q); + sdev = scsi_device_from_queue(q); if (!sdev) return err; @@ -391,7 +377,7 @@ int scsi_dh_attach(struct request_queue struct scsi_device_handler *scsi_dh; int err = 0; - sdev = get_sdev_from_queue(q); + sdev = scsi_device_from_queue(q); if (!sdev) return -ENODEV; @@ -429,7 +415,7 @@ const char *scsi_dh_attached_handler_nam struct scsi_device *sdev; const char *handler_name = NULL; - sdev = get_sdev_from_queue(q); + sdev = scsi_device_from_queue(q); if (!sdev) return NULL; --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2215,6 +2215,29 @@ void scsi_mq_destroy_tags(struct Scsi_Ho blk_mq_free_tag_set(&shost->tag_set); } +/** + * scsi_device_from_queue - return sdev associated with a request_queue + * @q: The request queue to return the sdev from + * + * Return the sdev associated with a request queue or NULL if the + * request_queue does not reference a SCSI device. + */ +struct scsi_device *scsi_device_from_queue(struct request_queue *q) +{ + struct scsi_device *sdev = NULL; + + if (q->mq_ops) { + if (q->mq_ops == &scsi_mq_ops) + sdev = q->queuedata; + } else if (q->request_fn == scsi_request_fn) + sdev = q->queuedata; + if (!sdev || !get_device(&sdev->sdev_gendev)) + sdev = NULL; + + return sdev; +} +EXPORT_SYMBOL_GPL(scsi_device_from_queue); + /* * Function: scsi_block_requests() * --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -307,6 +307,7 @@ extern void scsi_remove_device(struct sc extern int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh); void scsi_attach_vpd(struct scsi_device *sdev); +extern struct scsi_device *scsi_device_from_queue(struct request_queue *q); extern int scsi_device_get(struct scsi_device *); extern void scsi_device_put(struct scsi_device *); extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,