[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: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 371b69c..fa79e54 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -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 list_head hash_list;
struct request *rq;
+ u64 itn_id;
u64 tag;
};
@@ -185,12 +187,13 @@
}
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 @@
* @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 @@
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 @@
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 @@
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 @@
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;