Commit 2c47f9ef authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by James Bottomley
Browse files

[SCSI] tgt: add I_T nexus support 



tgt uses scsi_host as I_T nexus. This works for ibmvstgt because it
creates one scsi_host for one initiator. However, other target drivers
don't work like that.

This adds I_T nexus support, which enable one scsi_host to handle
multiple initiators. New scsi_tgt_it_nexus_create/destroy functions
are expected be called transport classes. For example, ibmvstgt
creates an initiator remote port, then the srp transport calls
tgt_it_nexus_create. tgt doesn't manages I_T nexus, instead it tells
tgtd, user-space daemon, to create a new I_T nexus.

On the receiving the response from tgtd, tgt calls
shost->transportt->it_nexus_response. transports should notify a
lld. The srp transport uses it_nexus_response callback in
srp_function_template to do that.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent aebd5e47

drivers/scsi/scsi_tgt_if.c

+38 −4
Original line number Diff line number Diff line
@@ -102,7 +102,8 @@ static int tgt_uspace_send_event(u32 type, struct tgt_event *p) 
	return 0;

}



int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 tag)

int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, u64 itn_id,

			     struct scsi_lun *lun, u64 tag)

{

	struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);

	struct tgt_event ev;
@@ -110,6 +111,7 @@ int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 ta 


	memset(&ev, 0, sizeof(ev));

	ev.p.cmd_req.host_no = shost->host_no;

	ev.p.cmd_req.itn_id = itn_id;

	ev.p.cmd_req.data_len = cmd->request_bufflen;

	memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb));

	memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun));
@@ -127,7 +129,7 @@ int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 ta 
	return err;

}



int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag)

int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 itn_id, u64 tag)

{

	struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);

	struct tgt_event ev;
@@ -135,6 +137,7 @@ int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag) 


	memset(&ev, 0, sizeof(ev));

	ev.p.cmd_done.host_no = shost->host_no;

	ev.p.cmd_done.itn_id = itn_id;

	ev.p.cmd_done.tag = tag;

	ev.p.cmd_done.result = cmd->result;
@@ -149,14 +152,15 @@ int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag) 
	return err;

}



int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,

				  struct scsi_lun *scsilun, void *data)

int scsi_tgt_uspace_send_tsk_mgmt(int host_no, u64 itn_id, int function,

				  u64 tag, struct scsi_lun *scsilun, void *data)

{

	struct tgt_event ev;

	int err;



	memset(&ev, 0, sizeof(ev));

	ev.p.tsk_mgmt_req.host_no = host_no;

	ev.p.tsk_mgmt_req.itn_id = itn_id;

	ev.p.tsk_mgmt_req.function = function;

	ev.p.tsk_mgmt_req.tag = tag;

	memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun));
@@ -172,6 +176,29 @@ int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag, 
	return err;

}



int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 itn_id,

					  int function, char *initiator_id)

{

	struct tgt_event ev;

	int err;



	memset(&ev, 0, sizeof(ev));

	ev.p.it_nexus_req.host_no = host_no;

	ev.p.it_nexus_req.function = function;

	ev.p.it_nexus_req.itn_id = itn_id;

	if (initiator_id)

		strncpy(ev.p.it_nexus_req.initiator_id, initiator_id,

			sizeof(ev.p.it_nexus_req.initiator_id));



	dprintk("%d %x %llx\n", host_no, function, (unsigned long long)itn_id);



	err = tgt_uspace_send_event(TGT_KEVENT_IT_NEXUS_REQ, &ev);

	if (err)

		eprintk("tx buf is full, could not send\n");



	return err;

}



static int event_recv_msg(struct tgt_event *ev)

{

	int err = 0;
@@ -179,6 +206,7 @@ static int event_recv_msg(struct tgt_event *ev) 
	switch (ev->hdr.type) {

	case TGT_UEVENT_CMD_RSP:

		err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no,

					   ev->p.cmd_rsp.itn_id,

					   ev->p.cmd_rsp.result,

					   ev->p.cmd_rsp.tag,

					   ev->p.cmd_rsp.uaddr,
@@ -189,9 +217,15 @@ static int event_recv_msg(struct tgt_event *ev) 
		break;

	case TGT_UEVENT_TSK_MGMT_RSP:

		err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no,

					       ev->p.tsk_mgmt_rsp.itn_id,

					       ev->p.tsk_mgmt_rsp.mid,

					       ev->p.tsk_mgmt_rsp.result);

		break;

	case TGT_UEVENT_IT_NEXUS_RSP:

		err = scsi_tgt_kspace_it_nexus_rsp(ev->p.it_nexus_rsp.host_no,

						   ev->p.it_nexus_rsp.itn_id,

						   ev->p.it_nexus_rsp.result);

		break;

	default:

		eprintk("unknown type %d\n", ev->hdr.type);

		err = -EINVAL;

drivers/scsi/scsi_tgt_lib.c

+70 −13
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <scsi/scsi_cmnd.h>

#include <scsi/scsi_device.h>

#include <scsi/scsi_host.h>

#include <scsi/scsi_transport.h>

#include <scsi/scsi_tgt.h>



#include "scsi_tgt_priv.h"
@@ -46,6 +47,7 @@ struct scsi_tgt_cmd { 


	struct list_head hash_list;

	struct request *rq;

	u64 itn_id;

	u64 tag;

};
@@ -185,12 +187,13 @@ static void scsi_tgt_cmd_destroy(struct work_struct *work) 
}



static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd,

			      u64 tag)

			      u64 itn_id, u64 tag)

{

	struct scsi_tgt_queuedata *qdata = rq->q->queuedata;

	unsigned long flags;

	struct list_head *head;



	tcmd->itn_id = itn_id;

	tcmd->tag = tag;

	tcmd->bio = NULL;

	INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy);
@@ -301,14 +304,14 @@ EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host); 
 * @scsilun:	scsi lun

 * @tag:	unique value to identify this command for tmf

 */

int scsi_tgt_queue_command(struct scsi_cmnd *cmd, struct scsi_lun *scsilun,

			   u64 tag)

int scsi_tgt_queue_command(struct scsi_cmnd *cmd, u64 itn_id,

			   struct scsi_lun *scsilun, u64 tag)

{

	struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;

	int err;



	init_scsi_tgt_cmd(cmd->request, tcmd, tag);

	err = scsi_tgt_uspace_send_cmd(cmd, scsilun, tag);

	init_scsi_tgt_cmd(cmd->request, tcmd, itn_id, tag);

	err = scsi_tgt_uspace_send_cmd(cmd, itn_id, scsilun, tag);

	if (err)

		cmd_hashlist_del(cmd);
@@ -326,7 +329,7 @@ static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd) 


	dprintk("cmd %p %lu\n", cmd, rq_data_dir(cmd->request));



	scsi_tgt_uspace_send_status(cmd, tcmd->tag);

	scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag);



	if (cmd->request_buffer)

		scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
@@ -459,7 +462,7 @@ static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag) 
	return rq;

}



int scsi_tgt_kspace_exec(int host_no, int result, u64 tag,

int scsi_tgt_kspace_exec(int host_no, u64 itn_id, int result, u64 tag,

			 unsigned long uaddr, u32 len, unsigned long sense_uaddr,

			 u32 sense_len, u8 rw)

{
@@ -541,21 +544,22 @@ done: 
	return err;

}



int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, int function, u64 tag,

			      struct scsi_lun *scsilun, void *data)

int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, u64 itn_id,

			      int function, u64 tag, struct scsi_lun *scsilun,

			      void *data)

{

	int err;



	/* TODO: need to retry if this fails. */

	err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, function,

					    tag, scsilun, data);

	err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, itn_id,

					    function, tag, scsilun, data);

	if (err < 0)

		eprintk("The task management request lost!\n");

	return err;

}

EXPORT_SYMBOL_GPL(scsi_tgt_tsk_mgmt_request);



int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result)

int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 itn_id, u64 mid, int result)

{

	struct Scsi_Host *shost;

	int err = -EINVAL;
@@ -573,7 +577,60 @@ int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result) 
		goto done;

	}



	err = shost->hostt->tsk_mgmt_response(mid, result);

	err = shost->hostt->tsk_mgmt_response(shost, itn_id, mid, result);

done:

	scsi_host_put(shost);

	return err;

}



int scsi_tgt_it_nexus_create(struct Scsi_Host *shost, u64 itn_id,

			     char *initiator)

{

	int err;



	/* TODO: need to retry if this fails. */

	err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no, itn_id, 0,

						    initiator);

	if (err < 0)

		eprintk("The i_t_neuxs request lost, %d %llx!\n",

			shost->host_no, (unsigned long long)itn_id);

	return err;

}

EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_create);



int scsi_tgt_it_nexus_destroy(struct Scsi_Host *shost, u64 itn_id)

{

	int err;



	/* TODO: need to retry if this fails. */

	err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no,

						    itn_id, 1, NULL);

	if (err < 0)

		eprintk("The i_t_neuxs request lost, %d %llx!\n",

			shost->host_no, (unsigned long long)itn_id);

	return err;

}

EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_destroy);



int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 itn_id, int result)

{

	struct Scsi_Host *shost;

	int err = -EINVAL;



	dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid);



	shost = scsi_host_lookup(host_no);

	if (IS_ERR(shost)) {

		printk(KERN_ERR "Could not find host no %d\n", host_no);

		return err;

	}



	if (!shost->uspace_req_q) {

		printk(KERN_ERR "Not target scsi host %d\n", host_no);

		goto done;

	}



	err = shost->transportt->it_nexus_response(shost, itn_id, result);

done:

	scsi_host_put(shost);

	return err;

drivers/scsi/scsi_tgt_priv.h

+14 −8
Original line number Diff line number Diff line
@@ -15,12 +15,18 @@ do { \ 
extern void scsi_tgt_if_exit(void);

extern int scsi_tgt_if_init(void);



extern int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun,

extern int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, u64 it_nexus_id,

				    struct scsi_lun *lun, u64 tag);

extern int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 it_nexus_id,

				       u64 tag);

extern int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag);

extern int scsi_tgt_kspace_exec(int host_no, int result, u64 tag,

				unsigned long uaddr, u32 len, unsigned long sense_uaddr,

				u32 sense_len, u8 rw);

extern int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,

extern int scsi_tgt_kspace_exec(int host_no, u64 it_nexus_id, int result, u64 tag,

				unsigned long uaddr, u32 len,

				unsigned long sense_uaddr, u32 sense_len, u8 rw);

extern int scsi_tgt_uspace_send_tsk_mgmt(int host_no, u64 it_nexus_id,

					 int function, u64 tag,

					 struct scsi_lun *scsilun, void *data);

extern int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 mid, int result);
 
extern int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 it_nexus_id,

				    u64 mid, int result);

extern int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 it_nexus_id,

						 int function, char *initiator);

extern int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 it_nexus_id, int result);

include/scsi/scsi_host.h

+1 −1
Original line number Diff line number Diff line
@@ -146,7 +146,7 @@ struct scsi_host_template { 
				  void (*done)(struct scsi_cmnd *));



	/* Used as callback for the completion of task management request. */

	int (* tsk_mgmt_response)(u64 mid, int result);

	int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64 mid, int result);



	/*

	 * This is an error handling strategy routine.  You don't need to

include/scsi/scsi_tgt.h

+5 −3
Original line number Diff line number Diff line
@@ -11,9 +11,11 @@ struct scsi_lun; 
extern struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *);

extern int scsi_tgt_alloc_queue(struct Scsi_Host *);

extern void scsi_tgt_free_queue(struct Scsi_Host *);

extern int scsi_tgt_queue_command(struct scsi_cmnd *, struct scsi_lun *, u64);

extern int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *, int, u64, struct scsi_lun *,

				     void *);

extern int scsi_tgt_queue_command(struct scsi_cmnd *, u64, struct scsi_lun *, u64);

extern int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *, u64, int, u64,

				     struct scsi_lun *, void *);

extern struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *,

					       enum dma_data_direction,	gfp_t);

extern void scsi_host_put_command(struct Scsi_Host *, struct scsi_cmnd *);

extern int scsi_tgt_it_nexus_create(struct Scsi_Host *, u64, char *);

extern int scsi_tgt_it_nexus_destroy(struct Scsi_Host *, u64);

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