name : scsi_transport_srp.h /* 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 scsi_timeout_action 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