bsg: split handling of SCSI CDBs vs transport requeues

The current BSG design tries to shoe-horn the transport-specific
passthrough commands into the overall framework for SCSI passthrough
requests.  This has a couple problems:

 - each passthrough queue has to set the QUEUE_FLAG_SCSI_PASSTHROUGH flag
   despite not dealing with SCSI commands at all.  Because of that these
   queues could also incorrectly accept SCSI commands from in-kernel
   users or through the legacy SCSI_IOCTL_SEND_COMMAND ioctl.
 - the real SCSI bsg queues also incorrectly accept bsg requests of the
   BSG_SUB_PROTOCOL_SCSI_TRANSPORT type
 - the bsg transport code is almost unredable because it tries to reuse
   different SCSI concepts for its own purpose.

This patch instead adds a new bsg_ops structure to handle the two cases
differently, and thus solves all of the above problems.  Another side
effect is that the bsg-lib queues also don't need to embedd a
struct scsi_request anymore.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 7c0987616684..08acbabfae07 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -228,7 +228,6 @@ static int sas_bsg_initialize(struct Scsi_Host *shost, struct sas_rphy *rphy)
 	 */
 	blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
 	blk_queue_flag_set(QUEUE_FLAG_BIDI, q);
-	blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q);
 	return 0;
 }