kernel_optimize_test/include/linux/bsg.h
Christoph Hellwig 17cb960f29 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>
2018-03-13 11:40:24 -06:00

44 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BSG_H
#define _LINUX_BSG_H
#include <uapi/linux/bsg.h>
struct request;
#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 *);
};
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_scsi_register_queue(struct request_queue *q,
struct device *parent)
{
return 0;
}
static inline void bsg_unregister_queue(struct request_queue *q)
{
}
#endif /* CONFIG_BLK_DEV_BSG */
#endif /* _LINUX_BSG_H */