scsi_transport_srp: Add transport layer error handling

[platform/adaptation/renesas_rcar/renesas_kernel.git] / include / scsi / scsi_transport_srp.h

diff --git a/include/scsi/scsi_transport_srp.h b/include/scsi/scsi_transport_srp.h
index 5a2d2d1..ee70016 100644 (file)
--- a/include/scsi/scsi_transport_srp.h
+++ b/include/scsi/scsi_transport_srp.h
@@ -13,6 +13,26 @@ struct srp_rport_identifiers {
        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:      Device loss timer has expired; port is being removed.
+ */
+enum srp_rport_state {
+       SRP_RPORT_RUNNING,
+       SRP_RPORT_BLOCKED,
+       SRP_RPORT_FAIL_FAST,
+       SRP_RPORT_LOST,
+};
+
+/**
+ * struct srp_rport
+ * @lld_data: LLD private data.
+ * @mutex:    Protects against concurrent rport fast_io_fail / dev_loss_tmo.
+ */
 struct srp_rport {
        /* for initiator and target drivers */
 
@@ -23,11 +43,38 @@ struct srp_rport {
 
        /* for initiator drivers */
 
-       void *lld_data; /* LLD private data */
+       void                    *lld_data;
+
+       struct mutex            mutex;
+       enum srp_rport_state    state;
+       bool                    deleted;
+       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
+ * @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.
+ * @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.
+ */
 struct srp_function_template {
        /* for initiator drivers */
+       bool has_rport_state;
+       bool reset_timer_if_blocked;
+       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);
        /* for target drivers */
        int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
@@ -43,7 +90,30 @@ 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 fast_io_fail_tmo, int dev_loss_tmo);
+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 *);
 
+/**
+ * srp_chkready() - evaluate the transport layer state before I/O
+ *
+ * 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