SCST events infrastructure

Prepared with help from Prasidh Srikanth <Prasidh.Srikanth@sandisk.com>



git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@6574 d57e44dd-8a1f-0410-8b47-8ef2f437770f

scst/include/scst_event.h

@@ -0,0 +1,131 @@
+/*
+ *  include/scst_event.h
+ *
+ *  Copyright (C) 2014 - 2015 SanDisk Corporation
+ *
+ *  Contains constants and data structures for scst_event module.
+ */
+
+#ifndef __SCST_EVENT_H
+#define __SCST_EVENT_H
+
+#ifdef __KERNEL__
+#include <linux/types.h>
+#endif
+
+#ifdef INSIDE_KERNEL_TREE
+#include <scst/scst_const.h>
+#else
+#include "scst_const.h"
+#endif
+
+#define SCST_EVENT_NAME			"scst_event"
+#define SCST_EVENT_PATH			"/dev/"
+#define SCST_EVENT_DEV			SCST_EVENT_PATH SCST_EVENT_NAME
+#define SCST_EVENT_VERSION_NAME		SCST_VERSION_NAME
+#define SCST_EVENT_VERSION		\
+	SCST_EVENT_VERSION_NAME "$Revision: 2454 $" SCST_CONST_VERSION
+
+#ifndef aligned_u64
+#define aligned_u64 uint64_t __attribute__((aligned(8)))
+#endif
+
+/*
+ * Due to variable size, this structure must always be last in any outer
+ * structure!
+ */
+struct scst_event {
+	int32_t payload_len;
+
+	uint32_t event_code;
+
+	uint32_t event_id; /* ID uniquely identifying this event */
+
+	/*
+	 * Event's issuer's name, i.e. SCST name of the corresponding module
+	 * (target driver or dev handler). SCST_EVENT_SCST_CORE_ISSUER for SCST
+	 * core.
+	 */
+	char issuer_name[SCST_MAX_NAME];
+
+	uint8_t payload[]; /* event's payload */
+};
+
+#ifdef __KERNEL__
+typedef void (*scst_event_done_notify_fn) (struct scst_event *event,
+	void *priv, int status);
+
+struct scst_event_entry {
+	struct list_head events_list_entry;
+	scst_event_done_notify_fn event_notify_fn;
+	void *notify_fn_priv;
+	unsigned long event_timeout; /* in jiffies */
+	int *pqueued_events_cnt;
+	union {
+		struct work_struct scst_event_queue_work;
+		struct delayed_work event_timeout_work;
+	};
+
+	struct scst_event event;
+	/* event's payload */
+};
+#endif
+
+struct scst_event_user {
+	int32_t max_event_size;
+	struct scst_event out_event;
+};
+
+struct scst_event_notify_done {
+	uint32_t event_id;
+	int status;
+};
+
+/* IOCTLs */
+#define SCST_EVENT_ALLOW_EVENT		_IOW('u', 1, struct scst_event)
+#define SCST_EVENT_DISALLOW_EVENT	_IOW('u', 2, struct scst_event)
+#define SCST_EVENT_GET_NEXT_EVENT	_IOWR('u', 3, struct scst_event_user)
+#define SCST_EVENT_NOTIFY_DONE		_IOW('u', 4, struct scst_event_notify_done)
+
+#ifdef __KERNEL__
+void scst_event_queue(uint32_t event_code, const char *issuer_name,
+	struct scst_event_entry *e);
+#endif
+
+/*************************************************************
+ ** SCST events
+ *************************************************************/
+
+/* SCST core issuer name */
+#define SCST_EVENT_SCST_CORE_ISSUER	"SCST core"
+
+/** SCST core's events **/
+
+#define SCST_EVENT_LUN_NOT_FOUND	1
+struct scst_event_lun_not_found_payload {
+	aligned_u64 lun;
+	uint8_t initiator_name[SCST_MAX_EXTERNAL_NAME];
+	uint8_t target_name[SCST_MAX_EXTERNAL_NAME];
+};
+
+#define SCST_EVENT_NEGATIVE_LUNS_INQUIRY 2
+struct scst_event_negative_luns_inquiry_payload {
+	uint8_t initiator_name[SCST_MAX_EXTERNAL_NAME];
+	uint8_t target_name[SCST_MAX_EXTERNAL_NAME];
+};
+
+#define SCST_EVENT_TM_FN_RECEIVED	4
+struct scst_event_tm_fn_received_payload {
+	uint32_t fn; /* TM fn */
+	aligned_u64 lun;
+	uint8_t device_name[SCST_MAX_EXTERNAL_NAME];
+	uint8_t initiator_name[SCST_MAX_EXTERNAL_NAME];
+	uint8_t target_name[SCST_MAX_EXTERNAL_NAME];
+	uint8_t session_sysfs_name[SCST_MAX_EXTERNAL_NAME];
+	struct { /* if ABORT TASK, then tag and CDB of cmd to abort */
+		aligned_u64 cmd_to_abort_tag;
+		uint8_t cdb[SCST_MAX_CDB_SIZE];
+	};
+};
+
+#endif /* __SCST_EVENT_H */

scst/src/Makefile

@@ -56,6 +56,7 @@ ifdef CONFIG_DLM_MODULE
 scst-y        += scst_dlm.o
 endif
 scst-y        += scst_tg.o
+scst-y        += scst_event.o
 obj-$(CONFIG_SCST)   += scst.o dev_handlers/
 
 obj-$(BUILD_DEV) += $(DEV_HANDLERS_DIR)/

scst/src/scst_main.c

@@ -2582,10 +2582,14 @@ static int __init init_scst(void)
 		goto out_destroy_sense_mempool;
 	}
 
-	res = scst_sysfs_init();
+	res = scst_event_init();
 	if (res != 0)
 		goto out_destroy_aen_mempool;
 
+	res = scst_sysfs_init();
+	if (res != 0)
+		goto out_event_exit;
+
 	scst_tg_init();
 
 	if (scst_max_cmd_mem == 0) {
@@ -2682,6 +2686,9 @@ out_destroy_sgv_pool:
 out_sysfs_cleanup:
 	scst_sysfs_cleanup();
 
+out_event_exit:
+	scst_event_exit();
+
 out_destroy_aen_mempool:
 	mempool_destroy(scst_aen_mempool);
 
@@ -2763,6 +2770,8 @@ static void __exit exit_scst(void)
 
 	scst_sysfs_cleanup();
 
+	scst_event_exit();
+
 #define DEINIT_CACHEP(p) do {		\
 		kmem_cache_destroy(p);	\
 		p = NULL;		\

scst/src/scst_priv.h

@@ -851,6 +851,14 @@ int gen_relative_target_port_id(uint16_t *id);
 bool scst_is_relative_target_port_id_unique(uint16_t id,
 	const struct scst_tgt *t);
 
+int scst_event_init(void);
+void scst_event_exit(void);
+
+int scst_event_queue_lun_not_found(const struct scst_cmd *cmd);
+int scst_event_queue_negative_luns_inquiry(const struct scst_tgt *tgt,
+	const char *initiator_name);
+int scst_event_queue_tm_fn_received(struct scst_mgmt_cmd *mcmd);
+
 typedef void __printf(2, 3) (*scst_show_fn)(void *arg, const char *fmt, ...);
 void scst_trace_cmds(scst_show_fn show, void *arg);
 void scst_trace_mcmds(scst_show_fn show, void *arg);