linux/include/scsi/scsi_dh.h
Bart Van Assche b8e162f9e7 scsi: core: Introduce enum scsi_disposition
Improve readability of the code in the SCSI core by introducing an
enumeration type for the values used internally that decide how to continue
processing a SCSI command. The eh_*_handler return values have not been
changed because that would involve modifying all SCSI drivers.

The output of the following command has been inspected to verify that no
out-of-range values are assigned to a variable of type enum
scsi_disposition:

KCFLAGS=-Wassign-enum make CC=clang W=1 drivers/scsi/

Link: https://lore.kernel.org/r/20210415220826.29438-6-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-04-15 22:44:40 -04:00

91 lines
2.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Header file for SCSI device handler infrastructure.
*
* Modified version of patches posted by Mike Christie <michaelc@cs.wisc.edu>
*
* Copyright IBM Corporation, 2007
* Authors:
* Chandra Seetharaman <sekharan@us.ibm.com>
* Mike Anderson <andmike@linux.vnet.ibm.com>
*/
#include <scsi/scsi_device.h>
enum {
SCSI_DH_OK = 0,
/*
* device errors
*/
SCSI_DH_DEV_FAILED, /* generic device error */
SCSI_DH_DEV_TEMP_BUSY,
SCSI_DH_DEV_UNSUPP, /* device handler not supported */
SCSI_DH_DEVICE_MAX, /* max device blkerr definition */
/*
* transport errors
*/
SCSI_DH_NOTCONN = SCSI_DH_DEVICE_MAX + 1,
SCSI_DH_CONN_FAILURE,
SCSI_DH_TRANSPORT_MAX, /* max transport blkerr definition */
/*
* driver and generic errors
*/
SCSI_DH_IO = SCSI_DH_TRANSPORT_MAX + 1, /* generic error */
SCSI_DH_INVALID_IO,
SCSI_DH_RETRY, /* retry the req, but not immediately */
SCSI_DH_IMM_RETRY, /* immediately retry the req */
SCSI_DH_TIMED_OUT,
SCSI_DH_RES_TEMP_UNAVAIL,
SCSI_DH_DEV_OFFLINED,
SCSI_DH_NOMEM,
SCSI_DH_NOSYS,
SCSI_DH_DRIVER_MAX,
};
typedef void (*activate_complete)(void *, int);
struct scsi_device_handler {
/* Used by the infrastructure */
struct list_head list; /* list of scsi_device_handlers */
/* Filled by the hardware handler */
struct module *module;
const char *name;
enum scsi_disposition (*check_sense)(struct scsi_device *,
struct scsi_sense_hdr *);
int (*attach)(struct scsi_device *);
void (*detach)(struct scsi_device *);
int (*activate)(struct scsi_device *, activate_complete, void *);
blk_status_t (*prep_fn)(struct scsi_device *, struct request *);
int (*set_params)(struct scsi_device *, const char *);
void (*rescan)(struct scsi_device *);
};
#ifdef CONFIG_SCSI_DH
extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);
extern int scsi_dh_attach(struct request_queue *, const char *);
extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);
extern int scsi_dh_set_params(struct request_queue *, const char *);
#else
static inline int scsi_dh_activate(struct request_queue *req,
activate_complete fn, void *data)
{
fn(data, 0);
return 0;
}
static inline int scsi_dh_attach(struct request_queue *req, const char *name)
{
return SCSI_DH_NOSYS;
}
static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
gfp_t gfp)
{
return NULL;
}
static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
{
return -SCSI_DH_NOSYS;
}
#endif