Starting multipath on a cciss device will cause a kernel warning to be triggered. Problem is that we're using the ->queuedata field of the request_queue to derefence the scsi device; however, for other (non-SCSI) devices this points to a totally different structure. So we should rather be using accessors here which make sure we're only returning valid SCSI device structures.
Signed-off-by: Hannes Reinecke <[email protected]> --- drivers/scsi/device_handler/scsi_dh.c | 6 +++--- drivers/scsi/scsi_lib.c | 11 +++++++++++ include/scsi/scsi_device.h | 1 + 3 files changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c index 33e422e..b89f204 100644 --- a/drivers/scsi/device_handler/scsi_dh.c +++ b/drivers/scsi/device_handler/scsi_dh.c @@ -388,7 +388,7 @@ int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) struct device *dev = NULL; spin_lock_irqsave(q->queue_lock, flags); - sdev = q->queuedata; + sdev = scsi_device_from_queue(q); if (!sdev) { spin_unlock_irqrestore(q->queue_lock, flags); err = SCSI_DH_NOSYS; @@ -484,7 +484,7 @@ int scsi_dh_attach(struct request_queue *q, const char *name) return -EINVAL; spin_lock_irqsave(q->queue_lock, flags); - sdev = q->queuedata; + sdev = scsi_device_from_queue(q); if (!sdev || !get_device(&sdev->sdev_gendev)) err = -ENODEV; spin_unlock_irqrestore(q->queue_lock, flags); @@ -513,7 +513,7 @@ void scsi_dh_detach(struct request_queue *q) struct scsi_device_handler *scsi_dh = NULL; spin_lock_irqsave(q->queue_lock, flags); - sdev = q->queuedata; + sdev = scsi_device_from_queue(q); if (!sdev || !get_device(&sdev->sdev_gendev)) sdev = NULL; spin_unlock_irqrestore(q->queue_lock, flags); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 7bd7f0d..12184a4 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1668,6 +1668,17 @@ out: spin_lock_irq(q->queue_lock); } +struct scsi_device *scsi_device_from_queue(struct request_queue *q) +{ + struct scsi_device *sdev = NULL; + + if (q->request_fn == scsi_request_fn) + sdev = q->queuedata; + + return sdev; +} +EXPORT_SYMBOL_GPL(scsi_device_from_queue); + u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) { struct device *host_dev; diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index d65fbec..4d43642 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -325,6 +325,7 @@ extern void starget_for_each_device(struct scsi_target *, void *, extern void __starget_for_each_device(struct scsi_target *, void *, void (*fn)(struct scsi_device *, void *)); +extern struct scsi_device *scsi_device_from_queue(struct request_queue *); /* only exposed to implement shost_for_each_device */ extern struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *, -- 1.7.12.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
