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>
diff --git a/include/linux/bsg.h b/include/linux/bsg.h
index 2a202e4..0c7dd9c 100644
--- a/include/linux/bsg.h
+++ b/include/linux/bsg.h
@@ -1,34 +1,43 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef BSG_H
-#define BSG_H
+#ifndef _LINUX_BSG_H
+#define _LINUX_BSG_H
#include <uapi/linux/bsg.h>
+struct request;
-#if defined(CONFIG_BLK_DEV_BSG)
+#ifdef CONFIG_BLK_DEV_BSG
+struct bsg_ops {
+ int (*check_proto)(struct sg_io_v4 *hdr);
+ int (*fill_hdr)(struct request *rq, struct sg_io_v4 *hdr,
+ fmode_t mode);
+ int (*complete_rq)(struct request *rq, struct sg_io_v4 *hdr);
+ void (*free_rq)(struct request *rq);
+};
+
struct bsg_class_device {
struct device *class_dev;
struct device *parent;
int minor;
struct request_queue *queue;
struct kref ref;
+ const struct bsg_ops *ops;
void (*release)(struct device *);
};
-extern int bsg_register_queue(struct request_queue *q,
- struct device *parent, const char *name,
- void (*release)(struct device *));
-extern void bsg_unregister_queue(struct request_queue *);
+int bsg_register_queue(struct request_queue *q, struct device *parent,
+ const char *name, const struct bsg_ops *ops,
+ void (*release)(struct device *));
+int bsg_scsi_register_queue(struct request_queue *q, struct device *parent);
+void bsg_unregister_queue(struct request_queue *q);
#else
-static inline int bsg_register_queue(struct request_queue *q,
- struct device *parent, const char *name,
- void (*release)(struct device *))
+static inline int bsg_scsi_register_queue(struct request_queue *q,
+ struct device *parent)
{
return 0;
}
static inline void bsg_unregister_queue(struct request_queue *q)
{
}
-#endif
-
-#endif
+#endif /* CONFIG_BLK_DEV_BSG */
+#endif /* _LINUX_BSG_H */