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scsi_transport_srp.h
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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef SCSI_TRANSPORT_SRP_H
#define SCSI_TRANSPORT_SRP_H
#include <linux/transport_class.h>
#include <linux/types.h>
#include <linux/mutex.h>
#define SRP_RPORT_ROLE_INITIATOR 0
#define SRP_RPORT_ROLE_TARGET 1
struct srp_rport_identifiers {
u8 port_id[16];
u8 roles;
};
/**
* enum srp_rport_state - SRP transport layer state
* @SRP_RPORT_RUNNING: Transport layer operational.
* @SRP_RPORT_BLOCKED: Transport layer not operational; fast I/O fail timer
* is running and I/O has been blocked.
* @SRP_RPORT_FAIL_FAST: Fast I/O fail timer has expired; fail I/O fast.
* @SRP_RPORT_LOST: Port is being removed.
*/
enum srp_rport_state {
SRP_RPORT_RUNNING,
SRP_RPORT_BLOCKED,
SRP_RPORT_FAIL_FAST,
SRP_RPORT_LOST,
};
/**
* struct srp_rport - SRP initiator or target port
*
* Fields that are relevant for SRP initiator and SRP target drivers:
* @dev: Device associated with this rport.
* @port_id: 16-byte port identifier.
* @roles: Role of this port - initiator or target.
*
* Fields that are only relevant for SRP initiator drivers:
* @lld_data: LLD private data.
* @mutex: Protects against concurrent rport reconnect /
* fast_io_fail / dev_loss_tmo activity.
* @state: rport state.
* @reconnect_delay: Reconnect delay in seconds.
* @failed_reconnects: Number of failed reconnect attempts.
* @reconnect_work: Work structure used for scheduling reconnect attempts.
* @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
* @dev_loss_tmo: Device loss timeout in seconds.
* @fast_io_fail_work: Work structure used for scheduling fast I/O fail work.
* @dev_loss_work: Work structure used for scheduling device loss work.
*/
struct srp_rport {
/* for initiator and target drivers */
struct device dev;
u8 port_id[16];
u8 roles;
/* for initiator drivers */
void *lld_data;
struct mutex mutex;
enum srp_rport_state state;
int reconnect_delay;
int failed_reconnects;
struct delayed_work reconnect_work;
int fast_io_fail_tmo;
int dev_loss_tmo;
struct delayed_work fast_io_fail_work;
struct delayed_work dev_loss_work;
};
/**
* struct srp_function_template
*
* Fields that are only relevant for SRP initiator drivers:
* @has_rport_state: Whether or not to create the state, fast_io_fail_tmo and
* dev_loss_tmo sysfs attribute for an rport.
* @reset_timer_if_blocked: Whether or srp_timed_out() should reset the command
* timer if the device on which it has been queued is blocked.
* @reconnect_delay: If not NULL, points to the default reconnect_delay value.
* @fast_io_fail_tmo: If not NULL, points to the default fast_io_fail_tmo value.
* @dev_loss_tmo: If not NULL, points to the default dev_loss_tmo value.
* @reconnect: Callback function for reconnecting to the target. See also
* srp_reconnect_rport().
* @terminate_rport_io: Callback function for terminating all outstanding I/O
* requests for an rport.
* @rport_delete: Callback function that deletes an rport.
*/
struct srp_function_template {
/* for initiator drivers */
bool has_rport_state;
bool reset_timer_if_blocked;
int *reconnect_delay;
int *fast_io_fail_tmo;
int *dev_loss_tmo;
int (*reconnect)(struct srp_rport *rport);
void (*terminate_rport_io)(struct srp_rport *rport);
void (*rport_delete)(struct srp_rport *rport);
};
extern struct scsi_transport_template *
srp_attach_transport(struct srp_function_template *);
extern void srp_release_transport(struct scsi_transport_template *);
extern void srp_rport_get(struct srp_rport *rport);
extern void srp_rport_put(struct srp_rport *rport);
extern struct srp_rport *srp_rport_add(struct Scsi_Host *,
struct srp_rport_identifiers *);
extern void srp_rport_del(struct srp_rport *);
extern int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo,
long dev_loss_tmo);
int srp_parse_tmo(int *tmo, const char *buf);
extern int srp_reconnect_rport(struct srp_rport *rport);
extern void srp_start_tl_fail_timers(struct srp_rport *rport);
extern void srp_remove_host(struct Scsi_Host *);
extern void srp_stop_rport_timers(struct srp_rport *rport);
enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd);
/**
* srp_chkready() - evaluate the transport layer state before I/O
* @rport: SRP target port pointer.
*
* Returns a SCSI result code that can be returned by the LLD queuecommand()
* implementation. The role of this function is similar to that of
* fc_remote_port_chkready().
*/
static inline int srp_chkready(struct srp_rport *rport)
{
switch (rport->state) {
case SRP_RPORT_RUNNING:
case SRP_RPORT_BLOCKED:
default:
return 0;
case SRP_RPORT_FAIL_FAST:
return DID_TRANSPORT_FAILFAST << 16;
case SRP_RPORT_LOST:
return DID_NO_CONNECT << 16;
}
}
#endif