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Commit 3f993063 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

iscsi-target: Add iscsit_transport API template 



Add basic struct iscsit_transport API template to allow iscsi-target for
running with external transport modules using existing iscsi_target_core.h
code.

For all external modules, this calls try_module_get() and module_put()
to obtain + release an external iscsit_transport module reference count.

Also include the iscsi-target symbols necessary in iscsi_transport.h to
allow external transport modules to function.

v3 changes:
- Add iscsit_build_reject export for ISTATE_SEND_REJECT usage

v2 changes:

- Drop unnecessary export of iscsit_get_transport + iscsit_put_transport (roland)
- Add ->iscsit_queue_data_in() to remove extra context switch on RDMA_WRITE
- Add ->iscsit_queue_status() to remove extra context switch on IB_SEND status
- Add ->iscsit_get_dataout() to remove extra context switch on RDMA_READ
- Drop ->iscsit_free_cmd()
- Drop ->iscsit_unmap_cmd()
- Rename iscsit_create_transport() -> iscsit_register_transport() (andy)
- Rename iscsit_destroy_transport() -> iscsit_unregister_transport() (andy)

Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 20361e69

drivers/target/iscsi/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ iscsi_target_mod-y += iscsi_target_parameters.o \ 
				iscsi_target_util.o \

				iscsi_target.o \

				iscsi_target_configfs.o \

				iscsi_target_stat.o

				iscsi_target_stat.o \

				iscsi_target_transport.o



obj-$(CONFIG_ISCSI_TARGET)	+= iscsi_target_mod.o

drivers/target/iscsi/iscsi_target_transport.c

0 → 100644
+55 −0
Original line number Diff line number Diff line 
#include <linux/spinlock.h>

#include <linux/list.h>

#include <target/iscsi/iscsi_transport.h>



static LIST_HEAD(g_transport_list);

static DEFINE_MUTEX(transport_mutex);



struct iscsit_transport *iscsit_get_transport(int type)

{

	struct iscsit_transport *t;



	mutex_lock(&transport_mutex);

	list_for_each_entry(t, &g_transport_list, t_node) {

		if (t->transport_type == type) {

			if (t->owner && !try_module_get(t->owner)) {

				t = NULL;

			}

			mutex_unlock(&transport_mutex);

			return t;

		}

	}

	mutex_unlock(&transport_mutex);



	return NULL;

}



void iscsit_put_transport(struct iscsit_transport *t)

{

	if (t->owner)

		module_put(t->owner);

}



int iscsit_register_transport(struct iscsit_transport *t)

{

	INIT_LIST_HEAD(&t->t_node);



	mutex_lock(&transport_mutex);

	list_add_tail(&t->t_node, &g_transport_list);

	mutex_unlock(&transport_mutex);



	pr_debug("Registered iSCSI transport: %s\n", t->name);



	return 0;

}

EXPORT_SYMBOL(iscsit_register_transport);



void iscsit_unregister_transport(struct iscsit_transport *t)

{

	mutex_lock(&transport_mutex);

	list_del(&t->t_node);

	mutex_unlock(&transport_mutex);



	pr_debug("Unregistered iSCSI transport: %s\n", t->name);

}

EXPORT_SYMBOL(iscsit_unregister_transport);

include/target/iscsi/iscsi_transport.h

0 → 100644
+83 −0
Original line number Diff line number Diff line 
#include <linux/module.h>

#include <linux/list.h>

#include "../../../drivers/target/iscsi/iscsi_target_core.h"



struct iscsit_transport {

#define ISCSIT_TRANSPORT_NAME	16

	char name[ISCSIT_TRANSPORT_NAME];

	int transport_type;

	struct module *owner;

	struct list_head t_node;

	int (*iscsit_setup_np)(struct iscsi_np *, struct __kernel_sockaddr_storage *);

	int (*iscsit_accept_np)(struct iscsi_np *, struct iscsi_conn *);

	void (*iscsit_free_np)(struct iscsi_np *);

	void (*iscsit_free_conn)(struct iscsi_conn *);

	struct iscsi_cmd *(*iscsit_alloc_cmd)(struct iscsi_conn *, gfp_t);

	int (*iscsit_get_login_rx)(struct iscsi_conn *, struct iscsi_login *);

	int (*iscsit_put_login_tx)(struct iscsi_conn *, struct iscsi_login *, u32);

	int (*iscsit_immediate_queue)(struct iscsi_conn *, struct iscsi_cmd *, int);

	int (*iscsit_response_queue)(struct iscsi_conn *, struct iscsi_cmd *, int);

	int (*iscsit_get_dataout)(struct iscsi_conn *, struct iscsi_cmd *, bool);

	int (*iscsit_queue_data_in)(struct iscsi_conn *, struct iscsi_cmd *);

	int (*iscsit_queue_status)(struct iscsi_conn *, struct iscsi_cmd *);

};



/*

 * From iscsi_target_transport.c

 */



extern int iscsit_register_transport(struct iscsit_transport *);

extern void iscsit_unregister_transport(struct iscsit_transport *);

extern struct iscsit_transport *iscsit_get_transport(int);

extern void iscsit_put_transport(struct iscsit_transport *);



/*

 * From iscsi_target.c

 */

extern int iscsit_add_reject_from_cmd(u8, int, int, unsigned char *,

				struct iscsi_cmd *);

extern int iscsit_setup_scsi_cmd(struct iscsi_conn *, struct iscsi_cmd *,

				unsigned char *);

extern void iscsit_set_unsoliticed_dataout(struct iscsi_cmd *);

extern int iscsit_process_scsi_cmd(struct iscsi_conn *, struct iscsi_cmd *,

				struct iscsi_scsi_req *);

extern int iscsit_check_dataout_hdr(struct iscsi_conn *, unsigned char *,

				struct iscsi_cmd **);

extern int iscsit_check_dataout_payload(struct iscsi_cmd *, struct iscsi_data *,

				bool);

extern int iscsit_handle_nop_out(struct iscsi_conn *, struct iscsi_cmd *,

				unsigned char *);

extern int iscsit_handle_logout_cmd(struct iscsi_conn *, struct iscsi_cmd *,

				unsigned char *);

extern int iscsit_handle_task_mgt_cmd(struct iscsi_conn *, struct iscsi_cmd *,

				unsigned char *);

extern void iscsit_build_rsp_pdu(struct iscsi_cmd *, struct iscsi_conn *,

				bool, struct iscsi_scsi_rsp *);

extern void iscsit_build_nopin_rsp(struct iscsi_cmd *, struct iscsi_conn *,

				struct iscsi_nopin *, bool);

extern void iscsit_build_task_mgt_rsp(struct iscsi_cmd *, struct iscsi_conn *,

				struct iscsi_tm_rsp *);

extern void iscsit_build_reject(struct iscsi_cmd *, struct iscsi_conn *,

				struct iscsi_reject *);

extern int iscsit_build_logout_rsp(struct iscsi_cmd *, struct iscsi_conn *,

				struct iscsi_logout_rsp *);

extern int iscsit_logout_post_handler(struct iscsi_cmd *, struct iscsi_conn *);

/*

 * From iscsi_target_device.c

 */

extern void iscsit_increment_maxcmdsn(struct iscsi_cmd *, struct iscsi_session *);

/*

 * From iscsi_target_erl1.c

 */

extern void iscsit_stop_dataout_timer(struct iscsi_cmd *);



/*

 * From iscsi_target_tmr.c

 */

extern int iscsit_tmr_post_handler(struct iscsi_cmd *, struct iscsi_conn *);



/*

 * From iscsi_target_util.c

 */

extern struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *, gfp_t);

extern int iscsit_sequence_cmd(struct iscsi_conn *, struct iscsi_cmd *, __be32);