linux/include/scsi/scsi_dh.h
Hannes Reinecke ae11b1b36d [SCSI] scsi_dh: attach to hardware handler from dm-mpath
multipath keeps a separate device table which may be
more current than the built-in one.
So we should make sure to always call ->attach whenever
a multipath map with hardware handler is instantiated.
And we should call ->detach on removal, too.

[sekharan: update as per comments from agk]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-07-26 15:14:53 -04:00

81 lines
2.4 KiB
C

/*
* Header file for SCSI device handler infrastruture.
*
* Modified version of patches posted by Mike Christie <michaelc@cs.wisc.edu>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* 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_NOSYS,
SCSI_DH_DRIVER_MAX,
};
#if defined(CONFIG_SCSI_DH) || defined(CONFIG_SCSI_DH_MODULE)
extern int scsi_dh_activate(struct request_queue *);
extern int scsi_dh_handler_exist(const char *);
extern int scsi_dh_attach(struct request_queue *, const char *);
extern void scsi_dh_detach(struct request_queue *);
#else
static inline int scsi_dh_activate(struct request_queue *req)
{
return 0;
}
static inline int scsi_dh_handler_exist(const char *name)
{
return 0;
}
static inline int scsi_dh_attach(struct request_queue *req, const char *name)
{
return SCSI_DH_NOSYS;
}
static inline void scsi_dh_detach(struct request_queue *q)
{
return;
}
#endif