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Diffstat (limited to 'include/scsi/scsi_transport_srp.h')
| -rw-r--r-- | include/scsi/scsi_transport_srp.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/include/scsi/scsi_transport_srp.h b/include/scsi/scsi_transport_srp.h new file mode 100644 index 000000000..d22df1258 --- /dev/null +++ b/include/scsi/scsi_transport_srp.h @@ -0,0 +1,145 @@ +/* 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 |